Commit Graph

411 Commits

Author SHA1 Message Date
Vineet Gupta 7d0857a54a ARC: [SMP] Disallow RTSC
RTSC is strictly incore and must not be allowed in SMP configs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-07 14:34:31 +05:30
Vineet Gupta 57e26e5745 ARC: [SMP] Fix build failures for large NR_CPUS
ST.as only takes S9 (255) for offset. This was going out of range when
accessing a task_struct field with 4k NR_CPUS (due to 128b of coumaks
itself in there).

Workaround by using an intermediate register to do the address scaling.

There is some duplication of fix for ctx_sw.c and ctx_sw_asm.S however
given that C version will go away soon I'm not bothering to factor out
the common code.

Reported-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:46 +05:30
Noam Camus 3aa4f80e41 ARC: [SMP] enlarge possible NR_CPUS
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:46 +05:30
Vineet Gupta 5ea72a9026 ARC: [SMP] TLB flush
- Add mm_cpumask setting (aggregating only, unlike some other arches)
  used to restrict the TLB flush cross-calling

- cross-calling versions of TLB flush routines (thanks to Noam)

Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:45 +05:30
Vineet Gupta 63eca94ca2 ARC: [SMP] ASID allocation
-Track a Per CPU ASID counter
-mm-per-cpu ASID (multiple threads, or mm migrated around)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:45 +05:30
Chen Gang b6fe8e7c01 arc: export symbol for pm_power_off in reset.c
Need export symbol for it, or can not pass compiling, the related error
with allmodconfig:

    MODPOST 2994 modules
  ERROR: "pm_power_off" [drivers/mfd/retu-mfd.ko] undefined!
  ERROR: "pm_power_off" [drivers/char/ipmi/ipmi_poweroff.ko] undefined!

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:44 +05:30
Chen Gang 8f146d0204 arc: export symbol for save_stack_trace() in stacktrace.c
Need export its symbol just like other architectures done, or can not
pass compiling with allmodconfig, the related error:

    MODPOST 2994 modules
  ERROR: "save_stack_trace" [kernel/backtracetest.ko] undefined!
  ERROR: "save_stack_trace" [drivers/md/persistent-data/dm-persistent-data.ko] undefined!

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:44 +05:30
Chen Gang 4782f7f9ae arc: remove '__init' for get_hw_config_num_irq()
get_hw_config_num_irq() may be called by normal iss_model_init_smp()
which is a function pointer for 'init_smp' which may be called by
first_lines_of_secondary() which also need be normal too.

The related warning (with allmodconfig):

    MODPOST vmlinux.o
  WARNING: vmlinux.o(.text+0x5814): Section mismatch in reference from the function iss_model_init_smp() to the function .init.text:get_hw_config_num_irq()
  The function iss_model_init_smp() references
  the function __init get_hw_config_num_irq().
  This is often because iss_model_init_smp lacks a __init
  annotation or the annotation of get_hw_config_num_irq is wrong.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
2013-11-06 10:41:43 +05:30
Chen Gang 8f5d221b06 arc: remove '__init' for first_lines_of_secondary()
first_lines_of_secondary() is a '__init' function, but it may be called
by __cpu_up() by _cpu_up() by cpu_up() which is a normal export symbol
function. So recommend to remove '__init'.

The related warning (with allmodconfig):

    MODPOST vmlinux.o
  WARNING: vmlinux.o(.text+0x315c): Section mismatch in reference from the function __cpu_up() to the function .init.text:first_lines_of_secondary()
  The function __cpu_up() references
  the function __init first_lines_of_secondary().
  This is often because __cpu_up lacks a __init
  annotation or the annotation of first_lines_of_secondary is wrong.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
2013-11-06 10:41:43 +05:30
Chen Gang ef3a661af6 arc: remove '__init' for setup_processor() and arc_init_IRQ()
They haven't '__init' in definition, but has '__init' in declaration.
And normal function start_kernel_secondary() may call setup_processor()
which will call arc_init_IRQ().

So need remove '__init' for both of them. The related warning (with
allmodconfig):

    MODPOST vmlinux.o
  WARNING: vmlinux.o(.text+0x3084): Section mismatch in reference from the function start_kernel_secondary() to the function .init.text:setup_processor()
  The function start_kernel_secondary() references
  the function __init setup_processor().
  This is often because start_kernel_secondary lacks a __init
  annotation or the annotation of setup_processor is wrong.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
2013-11-06 10:41:42 +05:30
Chen Gang 3d01c1ce41 arc: kgdb: add default implementation for kgdb_roundup_cpus()
arc supports kgdb, but need update -- add function kgdb_roundup_cpus(),
or can not pass compiling. At present, add the simple generic one just
like other architectures(e.g. tile, mips ...).

The related error (with allmodconfig):

  kernel/built-in.o: In function `kgdb_cpu_enter':
  kernel/debug/debug_core.c:580: undefined reference to `kgdb_roundup_cpus'

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:41 +05:30
Vineet Gupta 0a4c40a3b7 ARC: Fix bogus gcc warning and micro-optimise TLB iteration loop
------------------>8----------------------
arch/arc/mm/tlb.c: In function ‘do_tlb_overlap_fault’:
arch/arc/mm/tlb.c:688:13: warning: array subscript is above array bounds
[-Warray-bounds]
         (pd0[n] & PAGE_MASK)) {
             ^
------------------>8----------------------

While at it, remove the usless last iteration of outer loop when reading
a TLB SET for duplicate entries.

Suggested-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:41 +05:30
Vineet Gupta 0dafafc3ef ARC: Add support for irqflags tracing and lockdep
Lockdep required a small fix to stacktrace API which was incorrectly
unwindign out of __switch_to for the current call frame.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:40 +05:30
Vineet Gupta 54c8bff14d ARC: Reset the value of Interrupt Priority Register
In case bootloader has changed the priority of one/more IRQ lines

Reported-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:40 +05:30
Vineet Gupta 07ba69a46c ARC: Reduce #ifdef'ery for unaligned access emulation
Emulation not enabled is treated as if the fixup failed, so no need for
special #ifdef checks.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:39 +05:30
Vineet Gupta 21a63b5604 ARC: Change calling convention of do_page_fault()
switch the args (address, pt_regs) to match with all the other "C"
exception handlers.

This removes the awkwardness in EV_ProtV for page fault vs. unaligned
access.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:39 +05:30
Vineet Gupta d4599baf5c ARC: cacheflush optim - PTAG can be loop invariant if V-P is const
Line op needs vaddr (indexing) and paddr (tag match). For page sized
flushes (V-P const), each line op will need a different index, but the
tag bits wil remain constant, hence paddr can be setup once outside the
loop.

This improves select LMBench numbers for Aliasing dcache where we have
more "preventive" cache flushing.

Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
3.11-rc7- Linux 3.11.0-   80 4.66 8.88 69.7 112. 268. 8.60 28.0 3489 13.K 27.K	# Non alias ARC700
3.11-rc7- Linux 3.11.0-   80 4.64 8.51 68.6 98.5 271. 8.58 28.1 4160 15.K 32.K	# Aliasing
3.11-rc7- Linux 3.11.0-   80 4.64 8.51 69.8 99.4 270. 8.73 27.5 3880 15.K 31.K	# PTAG loop Inv

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:38 +05:30
Vineet Gupta bd12976c36 ARC: cacheflush refactor #3: Unify the {d,i}cache flush leaf helpers
With Line length being constant now, we can fold the 2 helpers into 1.
This allows applying any optimizations (forthcoming) to single place.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:38 +05:30
Vineet Gupta 63d2dfdbf4 ARC: cacheflush refactor #2: I and D caches lines to have same size
Having them be different seems an obscure configuration.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:37 +05:30
Vineet Gupta f3e4de3274 ARC: cacheflush refactor #1: push aux reg ascertaining into leaf routine
ARC dcache supports 3 ops - Inv, Flush, Flush-n-Inv.
The programming model however provides 2 commands FLUSH, INV.
INV will either discard or flush-n-discard (based on DT_CTRL bit)

The leaf helper __dc_line_loop() used to take the AUX register
(corresponding to the 2 commands). Now we push that to within the
helper, paving way for code consolidations to follow.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:29 +05:30
Vineet Gupta 064a626924 ARC: use __weak instead of __attribute__((weak))
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:40:37 +05:30
Vineet Gupta 8e457d6a75 ARC: Annotate some functions as static
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:40:37 +05:30
Christoph Lameter 6855e95ce3 arc: Replace __get_cpu_var uses
__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.

This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
2013-11-06 10:40:37 +05:30
Vineet Gupta 9c41f4eeb9 ARC: Incorrect mm reference used in vmalloc fault handler
A vmalloc fault needs to sync up PGD/PTE entry from init_mm to current
task's "active_mm".  ARC vmalloc fault handler however was using mm.

A vmalloc fault for non user task context (actually pre-userland, from
init thread's open for /dev/console) caused the handler to deref NULL mm
(for mm->pgd)

The reasons it worked so far is amazing:

1. By default (!SMP), vmalloc fault handler uses a cached value of PGD.
   In SMP that MMU register is repurposed hence need for mm pointer deref.

2. In pre-3.12 SMP kernel, the problem triggering vmalloc didn't exist in
   pre-userland code path - it was introduced with commit 20bafb3d23
   "n_tty: Move buffers into n_tty_data"

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: stable@vger.kernel.org    #3.10 and 3.11
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-02 10:27:04 -07:00
Ingo Molnar fb10d5b7ef Merge branch 'linus' into sched/core
Resolve cherry-picking conflicts:

Conflicts:
	mm/huge_memory.c
	mm/memory.c
	mm/mprotect.c

See this upstream merge commit for more details:

  52469b4fcd Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-01 08:24:41 +01:00
Anoop Thomas Mathew 23d6d3db66 doc: typo on word accounting in kprobes.c in mutliple architectures
Signed-off-by: Anoop Thomas Mathew <atm@profoundis.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-10-14 15:46:39 +02:00
Vineet Gupta 5b24282846 ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc"
ARCompact TRAP_S insn used for breakpoints, commits before exception is
taken (updating architectural PC). So ptregs->ret contains next-PC and
not the breakpoint PC itself. This is different from other restartable
exceptions such as TLB Miss where ptregs->ret has exact faulting PC.
gdb needs to know exact-PC hence ARC ptrace GETREGSET provides for
@stop_pc which returns ptregs->ret vs. EFA depending on the
situation.

However, writing stop_pc (SETREGSET request), which updates ptregs->ret
doesn't makes sense stop_pc doesn't always correspond to that reg as
described above.

This was not an issue so far since user_regs->ret / user_regs->stop_pc
had same value and both writing to ptregs->ret was OK, needless, but NOT
broken, hence not observed.

With gdb "jump", they diverge, and user_regs->ret updating ptregs is
overwritten immediately with stop_pc, which this patch fixes.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-12 12:00:36 +05:30
Rob Herring 5116b1defa of: remove empty arch prom.h headers
Now that prom.h is optional, all the empty prom.h headers can be removed.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
2013-10-09 20:04:13 -05:00
Rob Herring 32df8dca50 of: remove HAVE_ARCH_DEVTREE_FIXUPS
HAVE_ARCH_DEVTREE_FIXUPS appears to always be needed except for sparc,
but it is only used for /proc/device-teee and sparc does not enable
/proc/device-tree. So this option is redundant. Remove the option and
always enable it. This has the side effect of fixing /proc/device-tree
on arches such as arm64 which failed to define this option.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
2013-10-09 20:04:08 -05:00
Rob Herring be5973117b arc: remove unnecessary prom.h includes
Remove unnecessary prom.h includes in preparation to remove prom.h.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
2013-10-09 20:04:01 -05:00
Rob Herring 880beb8807 arc: use common of_flat_dt_match_machine
Convert arc to use the common of_flat_dt_match_machine function.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-09 20:03:55 -05:00
Rob Herring 29eb45a9ab of: remove early_init_dt_setup_initrd_arch
All arches do essentially the same thing now for
early_init_dt_setup_initrd_arch, so it can now be removed.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
2013-10-09 11:39:01 -05:00
Rob Herring ad81fcb530 arc: use early_init_dt_scan
Convert arc to use new early_init_dt_scan function.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-09 11:38:08 -05:00
Rob Herring 1efc959e0b arc: use unflatten_and_copy_device_tree
Use the common unflatten_and_copy_device_tree to copy the built-in FDT
out of init section.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
2013-10-09 11:38:03 -05:00
Ingo Molnar 37bf06375c Linux 3.12-rc4
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Merge tag 'v3.12-rc4' into sched/core

Merge Linux v3.12-rc4 to fix a conflict and also to refresh the tree
before applying more scheduler patches.

Conflicts:
	arch/avr32/include/asm/Kbuild

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:36:13 +02:00
Christian Ruppert 10469350e3 ARC: Fix signal frame management for SA_SIGINFO
Previously, when a signal was registered with SA_SIGINFO, parameters 2
and 3 of the signal handler were written to registers r1 and r2 before
the register set was saved. This led to corruption of these two
registers after returning from the signal handler (the wrong values were
restored).
With this patch, registers are now saved before any parameters are
passed, thus maintaining the processor state from before signal entry.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-03 09:43:56 +05:30
Uwe Kleine-König 55c2e26204 ARC: Use clockevents_config_and_register over clockevents_register_device
clockevents_config_and_register is more clever and correct than doing it
by hand; so use it.

[vgupta: fixed build failure due to missing ; in patch]

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-27 16:28:48 +05:30
Vineet Gupta 6c00350b57 ARC: Workaround spinlock livelock in SMP SystemC simulation
Some ARC SMP systems lack native atomic R-M-W (LLOCK/SCOND) insns and
can only use atomic EX insn (reg with mem) to build higher level R-M-W
primitives. This includes a SystemC based SMP simulation model.

So rwlocks need to use a protecting spinlock for atomic cmp-n-exchange
operation to update reader(s)/writer count.

The spinlock operation itself looks as follows:

	mov reg, 1		; 1=locked, 0=unlocked
retry:
	EX reg, [lock]		; load existing, store 1, atomically
	BREQ reg, 1, rety	; if already locked, retry

In single-threaded simulation, SystemC alternates between the 2 cores
with "N" insn each based scheduling. Additionally for insn with global
side effect, such as EX writing to shared mem, a core switch is
enforced too.

Given that, 2 cores doing a repeated EX on same location, Linux often
got into a livelock e.g. when both cores were fiddling with tasklist
lock (gdbserver / hackbench) for read/write respectively as the
sequence diagram below shows:

           core1                                   core2
         --------                                --------
1. spin lock [EX r=0, w=1] - LOCKED
2. rwlock(Read)            - LOCKED
3. spin unlock  [ST 0]     - UNLOCKED
                                         spin lock [EX r=0,w=1] - LOCKED
                      -- resched core 1----

5. spin lock [EX r=1] - ALREADY-LOCKED

                      -- resched core 2----
6.                                       rwlock(Write) - READER-LOCKED
7.                                       spin unlock [ST 0]
8.                                       rwlock failed, retry again

9.                                       spin lock  [EX r=0, w=1]
                      -- resched core 1----

10  spinlock locked in #9, retry #5
11. spin lock [EX gets 1]
                      -- resched core 2----
...
...

The fix was to unlock using the EX insn too (step 7), to trigger another
SystemC scheduling pass which would let core1 proceed, eliding the
livelock.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-27 16:28:48 +05:30
Vineet Gupta 0752adfda1 ARC: Fix 32-bit wrap around in access_ok()
Anton reported

 | LTP tests syscalls/process_vm_readv01 and process_vm_writev01 fail
 | similarly in one testcase test_iov_invalid -> lvec->iov_base.
 | Testcase expects errno EFAULT and return code -1,
 | but it gets return code 1 and ERRNO is 0 what means success.

Essentially test case was passing a pointer of -1 which access_ok()
was not catching. It was doing [@addr + @sz <= TASK_SIZE] which would
pass for @addr == -1

Fixed that by rewriting as [@addr <= TASK_SIZE - @sz]

Reported-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-27 16:28:47 +05:30
Mischa Jonker c11eb222fd ARC: Handle zero-overhead-loop in unaligned access handler
If a load or store is the last instruction in a zero-overhead-loop, and
it's misaligned, the loop would execute only once.

This fixes that problem.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-27 16:28:23 +05:30
Peter Zijlstra a787870924 sched, arch: Create asm/preempt.h
In order to prepare to per-arch implementations of preempt_count move
the required bits into an asm-generic header and use this for all
archs.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-h5j0c1r3e3fk015m30h8f1zx@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-25 14:07:50 +02:00
Martin Schwidefsky 0244ad004a Remove GENERIC_HARDIRQ config option
After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-09-13 15:09:52 +02:00
Linus Torvalds ac4de9543a Merge branch 'akpm' (patches from Andrew Morton)
Merge more patches from Andrew Morton:
 "The rest of MM.  Plus one misc cleanup"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  mm/Kconfig: add MMU dependency for MIGRATION.
  kernel: replace strict_strto*() with kstrto*()
  mm, thp: count thp_fault_fallback anytime thp fault fails
  thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page()
  thp: do_huge_pmd_anonymous_page() cleanup
  thp: move maybe_pmd_mkwrite() out of mk_huge_pmd()
  mm: cleanup add_to_page_cache_locked()
  thp: account anon transparent huge pages into NR_ANON_PAGES
  truncate: drop 'oldsize' truncate_pagecache() parameter
  mm: make lru_add_drain_all() selective
  memcg: document cgroup dirty/writeback memory statistics
  memcg: add per cgroup writeback pages accounting
  memcg: check for proper lock held in mem_cgroup_update_page_stat
  memcg: remove MEMCG_NR_FILE_MAPPED
  memcg: reduce function dereference
  memcg: avoid overflow caused by PAGE_ALIGN
  memcg: rename RESOURCE_MAX to RES_COUNTER_MAX
  memcg: correct RESOURCE_MAX to ULLONG_MAX
  mm: memcg: do not trap chargers with full callstack on OOM
  mm: memcg: rework and document OOM waiting and wakeup
  ...
2013-09-12 15:44:27 -07:00
Johannes Weiner 759496ba64 arch: mm: pass userspace fault flag to generic fault handler
Unlike global OOM handling, memory cgroup code will invoke the OOM killer
in any OOM situation because it has no way of telling faults occuring in
kernel context - which could be handled more gracefully - from
user-triggered faults.

Pass a flag that identifies faults originating in user space from the
architecture-specific fault handlers to generic code so that memcg OOM
handling can be improved.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 15:38:01 -07:00
Johannes Weiner 94bce453c7 arch: mm: remove obsolete init OOM protection
The memcg code can trap tasks in the context of the failing allocation
until an OOM situation is resolved.  They can hold all kinds of locks
(fs, mm) at this point, which makes it prone to deadlocking.

This series converts memcg OOM handling into a two step process that is
started in the charge context, but any waiting is done after the fault
stack is fully unwound.

Patches 1-4 prepare architecture handlers to support the new memcg
requirements, but in doing so they also remove old cruft and unify
out-of-memory behavior across architectures.

Patch 5 disables the memcg OOM handling for syscalls, readahead, kernel
faults, because they can gracefully unwind the stack with -ENOMEM.  OOM
handling is restricted to user triggered faults that have no other
option.

Patch 6 reworks memcg's hierarchical OOM locking to make it a little
more obvious wth is going on in there: reduce locked regions, rename
locking functions, reorder and document.

Patch 7 implements the two-part OOM handling such that tasks are never
trapped with the full charge stack in an OOM situation.

This patch:

Back before smart OOM killing, when faulting tasks were killed directly on
allocation failures, the arch-specific fault handlers needed special
protection for the init process.

Now that all fault handlers call into the generic OOM killer (see commit
609838cfed97: "mm: invoke oom-killer from remaining unconverted page
fault handlers"), which already provides init protection, the
arch-specific leftovers can be removed.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Acked-by: Vineet Gupta <vgupta@synopsys.com>	[arch/arc bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 15:38:01 -07:00
Noam Camus c3567f8a35 ARC: SMP failed to boot due to missing IVT setup
Commit 05b016ecf5 "ARC: Setup Vector Table Base in early boot" moved
the Interrupt vector Table setup out of arc_init_IRQ() which is called
for all CPUs, to entry point of boot cpu only, breaking booting of others.

Fix by adding the same to entry point of non-boot CPUs too.

read_arc_build_cfg_regs() printing IVT Base Register didn't help the
casue since it prints a synthetic value if zero which is totally bogus,
so fix that to print the exact Register.

[vgupta: Remove the now stale comment from header of arc_init_IRQ and
also added the commentary for halt-on-reset]

Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Cc: <stable@vger.kernel.org> #3.11
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 07:40:08 -07:00
Linus Torvalds 31f7c3a688 Device tree core updates for v3.12
Generally minor changes. A bunch of bug fixes, particularly for
 initialization and some refactoring. Most notable change if feeding the
 entire flattened tree into the random pool at boot. May not be
 significant, but shouldn't hurt either.
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Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux

Pull device tree core updates from Grant Likely:
 "Generally minor changes.  A bunch of bug fixes, particularly for
  initialization and some refactoring.  Most notable change if feeding
  the entire flattened tree into the random pool at boot.  May not be
  significant, but shouldn't hurt either"

Tim Bird questions whether the boot time cost of the random feeding may
be noticeable.  And "add_device_randomness()" is definitely not some
speed deamon of a function.

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
  of/platform: add error reporting to of_amba_device_create()
  irq/of: Fix comment typo for irq_of_parse_and_map
  of: Feed entire flattened device tree into the random pool
  of/fdt: Clean up casting in unflattening path
  of/fdt: Remove duplicate memory clearing on FDT unflattening
  gpio: implement gpio-ranges binding document fix
  of: call __of_parse_phandle_with_args from of_parse_phandle
  of: introduce of_parse_phandle_with_fixed_args
  of: move of_parse_phandle()
  of: move documentation of of_parse_phandle_with_args
  of: Fix missing memory initialization on FDT unflattening
  of: consolidate definition of early_init_dt_alloc_memory_arch()
  of: Make of_get_phy_mode() return int i.s.o. const int
  include: dt-binding: input: create a DT header defining key codes.
  of/platform: Staticize of_platform_device_create_pdata()
  of: Specify initrd location using 64-bit
  dt: Typo fix
  OF: make of_property_for_each_{u32|string}() use parameters if OF is not enabled
2013-09-10 13:53:52 -07:00
Vineet Gupta 07b9b65147 ARC: fix new Section mismatches in build (post __cpuinit cleanup)
--------------->8--------------------
WARNING: vmlinux.o(.text+0x708): Section mismatch in reference from the
function read_arc_build_cfg_regs() to the function
.init.text:read_decode_cache_bcr()

WARNING: vmlinux.o(.text+0x702): Section mismatch in reference from the
function read_arc_build_cfg_regs() to the function
.init.text:read_decode_mmu_bcr()
--------------->8--------------------

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-05 19:19:06 +05:30
Mischa Jonker 7efd0da2d1 ARC: Fix __udelay calculation
Cast usecs to u64, to ensure that the (usecs * 4295 * HZ)
multiplication is 64 bit.

Initially, the (usecs * 4295 * HZ) part was done as a 32 bit
multiplication, with the result casted to 64 bit. This led to some bits
falling off, causing a "DMA initialization error" in the stmmac Ethernet
driver, due to a premature timeout.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-05 10:31:12 +05:30
Mischa Jonker 8508d5653f ARC: remove console_verbose() from setup_arch()
It prevents kernel parameters such as 'loglevel' from doing their job.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-05 10:31:12 +05:30
Mischa Jonker 6532b02fe5 ARC: Add read*_relaxed to asm/io.h
Some drivers require these, and ARC didn't had them yet.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-05 10:31:11 +05:30
Noam Camus 7d669a193b ARC: Handle un-aligned user space access in BE.
Adding endian awarness to un-aligned access exception handling.

Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-05 10:31:11 +05:30
Vineet Gupta 947bf103fc ARC: [ASID] Track ASID allocation cycles/generations
This helps remove asid-to-mm reverse map

While mm->context.id contains the ASID assigned to a process, our ASID
allocator also used asid_mm_map[] reverse map. In a new allocation
cycle (mm->ASID >= @asid_cache), the Round Robin ASID allocator used this
to check if new @asid_cache belonged to some mm2 (from prev cycle).
If so, it could locate that mm using the ASID reverse map, and mark that
mm as unallocated ASID, to force it to refresh at the time of switch_mm()

However, for SMP, the reverse map has to be maintained per CPU, so
becomes 2 dimensional, hence got rid of it.

With reverse map gone, it is NOT possible to reach out to current
assignee. So we track the ASID allocation generation/cycle and
on every switch_mm(), check if the current generation of CPU ASID is
same as mm's ASID; If not it is refreshed.

(Based loosely on arch/sh implementation)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-30 21:42:19 +05:30
Vineet Gupta c60115537c ARC: [ASID] activate_mm() == switch_mm()
ASID allocation changes/2

Use the fact that switch_mm() and activate_mm() are exactly same code
now while acknowledging the semantical difference in comment

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-30 21:42:19 +05:30
Vineet Gupta 3daa48d1d9 ARC: [ASID] get_new_mmu_context() to conditionally allocate new ASID
ASID allocation changes/1

This patch does 2 things:

(1) get_new_mmu_context() NOW moves mm->ASID to a new value ONLY if it
    was from a prev allocation cycle/generation OR if mm had no ASID
    allocated (vs. before would unconditionally moving to a new ASID)

    Callers desiring unconditional update of ASID, e.g.local_flush_tlb_mm()
    (for parent's address space invalidation at fork) need to first force
    the parent to an unallocated ASID.

(2) get_new_mmu_context() always sets the MMU PID reg with unchanged/new
    ASID value.

The gains are:
- consolidation of all asid alloc logic into get_new_mmu_context()
- avoiding code duplication in switch_mm() for PID reg setting
- Enables future change to fold activate_mm() into switch_mm()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-30 21:42:18 +05:30
Vineet Gupta 5bd87adf9b ARC: [ASID] Refactor the TLB paranoid debug code
-Asm code already has values of SW and HW ASID values, so they can be
 passed to the printing routine.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-30 21:42:18 +05:30
Vineet Gupta ade922f8e2 ARC: [ASID] Remove legacy/unused debug code
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-30 21:42:17 +05:30
Vineet Gupta c0857f5d0e ARC: No need to flush the TLB in early boot
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-30 10:48:14 +05:30
Vineet Gupta 483e9bcb01 ARC: MMUv4 preps/3 - Abstract out TLB Insert/Delete
This reorganizes the current TLB operations into psuedo-ops to better
pair with MMUv4's native Insert/Delete operations

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-30 10:22:48 +05:30
Vineet Gupta d091fcb97f ARC: MMUv4 preps/2 - Reshuffle PTE bits
With previous commit freeing up PTE bits, reassign them so as to:

- Match the bit to H/w counterpart where possible
  (e.g. MMUv2 GLOBAL/PRESENT, this avoids a shift in create_tlb())
- Avoid holes in _PAGE_xxx definitions

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-30 10:19:12 +05:30
Vineet Gupta 64b703ef27 ARC: MMUv4 preps/1 - Fold PTE K/U access flags
The current ARC VM code has 13 flags in Page Table entry: some software
(accesed/dirty/non-linear-maps) and rest hardware specific. With 8k MMU
page, we need 19 bits for addressing page frame so remaining 13 bits is
just about enough to accomodate the current flags.

In MMUv4 there are 2 additional flags, SZ (normal or super page) and WT
(cache access mode write-thru) - and additionally PFN is 20 bits (vs. 19
before for 8k). Thus these can't be held in current PTE w/o making each
entry 64bit wide.

It seems there is some scope of compressing the current PTE flags (and
freeing up a few bits). Currently PTE contains fully orthogonal distinct
access permissions for kernel and user mode (Kr, Kw, Kx; Ur, Uw, Ux)
which can be folded into one set (R, W, X). The translation of 3 PTE
bits into 6 TLB bits (when programming the MMU) can be done based on
following pre-requites/assumptions:

1. For kernel-mode-only translations (vmalloc: 0x7000_0000 to
   0x7FFF_FFFF), PTE additionally has PAGE_GLOBAL flag set (and user
   space entries can never be global). Thus such a PTE can translate
   to Kr, Kw, Kx (as appropriate) and zero for User mode counterparts.

2. For non global entries, the PTE flags can be used to create mirrored
   K and U TLB bits. This is true after commit a950549c67
   "ARC: copy_(to|from)_user() to honor usermode-access permissions"
   which ensured that user-space translations _MUST_ have same access
   permissions for both U/K mode accesses so that  copy_{to,from}_user()
   play fair with fault based CoW break and such...

There is no such thing as free lunch - the cost is slightly infalted
TLB-Miss Handlers.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-29 17:51:36 +05:30
Vineet Gupta 4b06ff35fb ARC: Code cosmetics (Nothing semantical)
* reduce editor lines taken by pt_regs
* ARCompact ISA specific part of TLB Miss handlers clubbed together
* cleanup some comments

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-29 17:51:15 +05:30
Grant Likely a1727da599 of: consolidate definition of early_init_dt_alloc_memory_arch()
Most architectures use the same implementation. Collapse the common ones
into a single weak function that can be overridden.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
2013-08-28 21:18:32 +01:00
Grant Likely 8be137f266 Linux 3.11-rc7
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Merge tag 'v3.11-rc7' into devicetree/next

Linux 3.11-rc7
2013-08-28 20:18:13 +01:00
Vineet Gupta fce16bc35a ARC: Entry Handler tweaks: Optimize away redundant IRQ_DISABLE_SAVE
In the exception return path, for both U/K cases, intr are already
disabled (for various existing reasons). So when we drop down to
@restore_regs, we need not redo that.

There was subtle issue - when intr were NOT being disabled for
ret-to-kernel-but-no-preemption case - now fixed by moving the
IRQ_DISABLE further up in @resume_kernel_mode.

So what do we gain:

* Shaves off a few insn in return path.

* Eliminates the need for IRQ_DISABLE_SAVE assembler macro for ARCv2
  hence allows for entry code sharing.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-26 09:40:25 +05:30
Vineet Gupta 37f3ac498c ARC: Exception Handlers Code consolidation
After the recent cleanups, all the exception handlers now have same
boilerplate prologue code. Move that into common macro.

This reduces readability but helps greatly with sharing / duplicating
entry code with ARCv2 ISA where the handlers are pretty much the same,
just the entry prologue is different (due to hardware assist).

Also while at it, add the missing FAKE_RET_FROM_EXCPN calls in couple of
places to drop down to pure kernel mode (from exception mode) before
jumping off into "C" code.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-26 09:40:25 +05:30
Vineet Gupta fe240f11cd ARC: Add some .gitignore entries
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-26 09:40:24 +05:30
Joern Rennecke b0f55f2a1a ARC: [lib] strchr breakage in Big-endian configuration
For a search buffer, 2 byte aligned, strchr() was returning pointer
outside of buffer (buf - 1)

------------->8----------------
    // Input buffer (default 4 byte aigned)
    char *buffer = "1AA_";

    // actual search start (to mimick 2 byte alignment)
    char *current_line = &(buffer[2]);

    // Character to search for
    char c = 'A';

    char *c_pos = strchr(current_line, c);

    printf("%s\n", c_pos) --> 'AA_' as oppose to 'A_'
------------->8----------------

Reported-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Debugged-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Cc: <stable@vger.kernel.org> # [3.9 and 3.10]
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: Joern Rennecke  <joern.rennecke@embecosm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-24 11:24:53 -07:00
Vineet Gupta 4ffd9e2c4d ARC: SMP build breakage
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-07-26 15:34:22 -07:00
Santosh Shilimkar 374d5c9964 of: Specify initrd location using 64-bit
On some PAE architectures, the entire range of physical memory could reside
outside the 32-bit limit.  These systems need the ability to specify the
initrd location using 64-bit numbers.

This patch globally modifies the early_init_dt_setup_initrd_arch() function to
use 64-bit numbers instead of the current unsigned long.

There has been quite a bit of debate about whether to use u64 or phys_addr_t.
It was concluded to stick to u64 to be consistent with rest of the device
tree code. As summarized by Geert, "The address to load the initrd is decided
by the bootloader/user and set at that point later in time. The dtb should not
be tied to the kernel you are booting"

More details on the discussion can be found here:
https://lkml.org/lkml/2013/6/20/690
https://lkml.org/lkml/2012/9/13/544

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
2013-07-24 11:10:01 +01:00
Linus Torvalds 8f041e6ca1 Couple of Platform updates (Device Tree files primarily) given that the
corresponding drivers (net/ethernet/arc/*, irqctl/irq-tb10x.c) have now
 been merged into your tree.
 
 Ideally these shd have been part of same submissions, oh well...
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Merge tag 'arc-v3.11-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull second set of ARC architecture updates from Vineet Gupta:
 "Couple of Platform updates (Device Tree files primarily) given that
  the corresponding drivers (net/ethernet/arc/*, irqctl/irq-tb10x.c)
  have now been merged into your tree.

  Ideally these shd have been part of same submissions, oh well..."

* tag 'arc-v3.11-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [TB10x] Updates for irqchip driver
  ARC: [plat-arcfpga] Enable arc_emac for ARCAngle4 Board
2013-07-10 10:11:26 -07:00
Johannes Weiner 609838cfed mm: invoke oom-killer from remaining unconverted page fault handlers
A few remaining architectures directly kill the page faulting task in an
out of memory situation.  This is usually not a good idea since that
task might not even use a significant amount of memory and so may not be
the optimal victim to resolve the situation.

Since 2.6.29's 1c0fe6e ("mm: invoke oom-killer from page fault") there
is a hook that architecture page fault handlers are supposed to call to
invoke the OOM killer and let it pick the right task to kill.  Convert
the remaining architectures over to this hook.

To have the previous behavior of simply taking out the faulting task the
vm.oom_kill_allocating_task sysctl can be set to 1.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>   [arch/arc bits]
Cc: James Hogan <james.hogan@imgtec.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:20 -07:00
Linus Torvalds 98f486f18d Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 - new drivers: Kontron PLD, Wondermedia VT
 - mv64xxx driver gained sun4i support and a bigger cleanup
 - duplicate driver 'intel-mid' removed
 - added generic device tree binding for sda holding time (and
   designware driver already uses it)
 - we tried to allow driver probing with only device tree and no i2c
   ids, but I had to revert it because of side effects.  Needs some
   rethinking.
 - driver bugfixes, cleanups...

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (34 commits)
  i2c-designware: use div_u64 to fix link
  i2c: Kontron PLD i2c bus driver
  i2c: iop3xxx: fix build failure after waitqueue changes
  i2c-designware: make SDA hold time configurable
  i2c: mv64xxx: Set bus frequency to 100kHz if clock-frequency is not provided
  i2c: imx: allow autoloading on dt ids
  i2c: mv64xxx: Fix transfer error code
  i2c: i801: SMBus patch for Intel Coleto Creek DeviceIDs
  i2c: omap: correct usage of the interrupt enable register
  i2c-pxa: prepare clock before use
  Revert "i2c: core: make it possible to match a pure device tree driver"
  i2c: nomadik: allocate adapter number dynamically
  i2c: nomadik: support elder Nomadiks
  i2c: mv64xxx: Add Allwinner sun4i compatible
  i2c: mv64xxx: make the registers offset configurable
  i2c: mv64xxx: Add macros to access parts of registers
  i2c: vt8500: Add support for I2C bus on Wondermedia SoCs
  i2c: designware: fix race between subsequent xfers
  i2c: bfin-twi: Read and write the FIFO in loop
  i2c: core: make it possible to match a pure device tree driver
  ...
2013-07-04 14:02:09 -07:00
Linus Torvalds e61aca5158 Merge branch 'kconfig-diet' from Dave Hansen
Merge Kconfig menu diet patches from Dave Hansen:
 "I think the "Kernel Hacking" menu has gotten a bit out of hand.  It is
  over 120 lines long on my system with everything enabled and options
  are scattered around it haphazardly.

        http://sr71.net/~dave/linux/kconfig-horror.png

  Let's try to introduce some sanity.  This set takes that 120 lines
  down to 55 and makes it vastly easier to find some things.  It's a
  start.

  This set stands on its own, but there is plenty of room for follow-up
  patches.  The arch-specific debug options still end up getting stuck
  in the top-level "kernel hacking" menu.  OPTIMIZE_INLINING, for
  instance, could obviously go in to the "compiler options" menu, but
  the fact that it is defined in arch/ in a separate Kconfig file keeps
  it on its own for the moment.

  The Signed-off-by's in here look funky.  I changed employers while
  working on this set, so I have signoffs from both email addresses"

* emailed patches from Dave Hansen <dave@sr71.net>:
  hang and lockup detection menu
  kconfig: consolidate printk options
  group locking debugging options
  consolidate compilation option configs
  consolidate runtime testing configs
  order memory debugging Kconfig options
  consolidate per-arch stack overflow debugging options
2013-07-04 11:25:51 -07:00
Dave Hansen d1a1dc0be8 consolidate per-arch stack overflow debugging options
Original posting:

	http://lkml.kernel.org/r/20121214184202.F54094D9@kernel.stglabs.ibm.com

Several architectures have similar stack debugging config options.
They all pretty much do the same thing, some with slightly
differing help text.

This patch changes the architectures to instead enable a Kconfig
boolean, and then use that boolean in the generic Kconfig.debug
to present the actual menu option.  This removes a bunch of
duplication and adds consistency across arches.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-04 11:25:39 -07:00
Linus Torvalds 7f0ef0267e Merge branch 'akpm' (updates from Andrew Morton)
Merge first patch-bomb from Andrew Morton:
 - various misc bits
 - I'm been patchmonkeying ocfs2 for a while, as Joel and Mark have been
   distracted.  There has been quite a bit of activity.
 - About half the MM queue
 - Some backlight bits
 - Various lib/ updates
 - checkpatch updates
 - zillions more little rtc patches
 - ptrace
 - signals
 - exec
 - procfs
 - rapidio
 - nbd
 - aoe
 - pps
 - memstick
 - tools/testing/selftests updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (445 commits)
  tools/testing/selftests: don't assume the x bit is set on scripts
  selftests: add .gitignore for kcmp
  selftests: fix clean target in kcmp Makefile
  selftests: add .gitignore for vm
  selftests: add hugetlbfstest
  self-test: fix make clean
  selftests: exit 1 on failure
  kernel/resource.c: remove the unneeded assignment in function __find_resource
  aio: fix wrong comment in aio_complete()
  drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test mode
  drivers/memstick/host/r592.c: convert to module_pci_driver
  drivers/memstick/host/jmb38x_ms: convert to module_pci_driver
  pps-gpio: add device-tree binding and support
  drivers/pps/clients/pps-gpio.c: convert to module_platform_driver
  drivers/pps/clients/pps-gpio.c: convert to devm_* helpers
  drivers/parport/share.c: use kzalloc
  Documentation/accounting/getdelays.c: avoid strncpy in accounting tool
  aoe: update internal version number to v83
  aoe: update copyright date
  aoe: perform I/O completions in parallel
  ...
2013-07-03 17:12:13 -07:00
Jiang Liu de35e1b828 mm/ARC: prepare for removing num_physpages and simplify mem_init()
Prepare for removing num_physpages and simplify mem_init().

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>   # for arch/arc
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:35 -07:00
Jiang Liu 0c98853473 mm: concentrate modification of totalram_pages into the mm core
Concentrate code to modify totalram_pages into the mm core, so the arch
memory initialized code doesn't need to take care of it.  With these
changes applied, only following functions from mm core modify global
variable totalram_pages: free_bootmem_late(), free_all_bootmem(),
free_all_bootmem_node(), adjust_managed_page_count().

With this patch applied, it will be much more easier for us to keep
totalram_pages and zone->managed_pages in consistence.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:33 -07:00
Jiang Liu dbe67df4ba mm: enhance free_reserved_area() to support poisoning memory with zero
Address more review comments from last round of code review.
1) Enhance free_reserved_area() to support poisoning freed memory with
   pattern '0'. This could be used to get rid of poison_init_mem()
   on ARM64.
2) A previous patch has disabled memory poison for initmem on s390
   by mistake, so restore to the original behavior.
3) Remove redundant PAGE_ALIGN() when calling free_reserved_area().

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:32 -07:00
Jiang Liu 11199692d8 mm: change signature of free_reserved_area() to fix building warnings
Change signature of free_reserved_area() according to Russell King's
suggestion to fix following build warnings:

  arch/arm/mm/init.c: In function 'mem_init':
  arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default]
    free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
    ^
  In file included from include/linux/mman.h:4:0,
                   from arch/arm/mm/init.c:15:
  include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *'
   extern unsigned long free_reserved_area(unsigned long start, unsigned long end,

   mm/page_alloc.c: In function 'free_reserved_area':
>> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]
   In file included from arch/mips/include/asm/page.h:49:0,
                    from include/linux/mmzone.h:20,
                    from include/linux/gfp.h:4,
                    from include/linux/mm.h:8,
                    from mm/page_alloc.c:18:
   arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int'
   mm/page_alloc.c: In function 'free_area_init_nodes':
   mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds]

Also address some minor code review comments.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:32 -07:00
Linus Torvalds 76d3f4c27d ARC changes for 3.11
Highlights of changes:
 
 -Continuation of ARC MM changes from 3.10 including
    zero page optimization;
    Setting pagecache pages dirty by default;
    Non executable stack by default;
    Reducing dcache flushes for aliasing VIPT config
 
 -Long overdue rework of pt_regs machinery - removing the unused word gutters
  and adding ECR register to baseline (helps cleanup lot of low level code)
 
 -Support for ARC gcc 4.8
 
 -Few other preventive fixes, cosmetics, usage of Kconfig helper..
 
 The diffstat is larger than normal primarily because of arcregs.h header split
 as well as beautification of macros in entry.h
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Merge tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull first batch of ARC changes from Vineet Gupta:
 "There's a second bunch to follow next week - which depends on commits
  on other trees (irq/net).  I'd have preferred the accompanying ARC
  change via respective trees, but it didn't workout somehow.

  Highlights of changes:

   - Continuation of ARC MM changes from 3.10 including

       zero page optimization
       Setting pagecache pages dirty by default
       Non executable stack by default
       Reducing dcache flushes for aliasing VIPT config

   - Long overdue rework of pt_regs machinery - removing the unused word
     gutters and adding ECR register to baseline (helps cleanup lot of
     low level code)

   - Support for ARC gcc 4.8

   - Few other preventive fixes, cosmetics, usage of Kconfig helper..

  The diffstat is larger than normal primarily because of arcregs.h
  header split as well as beautification of macros in entry.h"

* tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (32 commits)
  ARC: warn on improper stack unwind FDE entries
  arc: delete __cpuinit usage from all arc files
  ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNT
  ARC: [tlb-miss] Extraneous PTE bit testing/setting
  ARC: Adjustments for gcc 4.8
  ARC: Setup Vector Table Base in early boot
  ARC: Remove explicit passing around of ECR
  ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
  ARC: stop using pt_regs->orig_r8
  ARC: pt_regs update #4: r25 saved/restored unconditionally
  ARC: K/U SP saved from one location in stack switching macro
  ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
  ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
  ARC: Increase readability of entry handlers
  ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
  ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
  ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
  ARC: pt_regs update #0: remove kernel stack canary
  ARC: [mm] Remove @write argument to do_page_fault()
  ARC: [mm] Make stack/heap Non-executable by default
  ...
2013-07-03 11:09:27 -07:00
Al Viro e77e430033 more open-coded file_inode() calls
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:21 +04:00
Al Viro 40d158e618 consolidate io_remap_pfn_range definitions
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:46:35 +04:00
Christian Ruppert 723e2b801d ARC: [TB10x] Updates for irqchip driver
Device tree and Kconfig updates for irqchip driver.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-28 15:07:42 +05:30
Alexey Brodkin d0e63ed941 ARC: [plat-arcfpga] Enable arc_emac for ARCAngle4 Board
* Add arc_emac to DeviceTree DT description
  "Documentation/devicetree/bindings/net/arc_emac.txt".

* Update defconfig correspondingly

[vgupta: tweaked changelog]
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-28 15:07:20 +05:30
Vineet Gupta baadb8fd0c ARC: warn on improper stack unwind FDE entries
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:37:59 +05:30
Paul Gortmaker ce7599567e arc: delete __cpuinit usage from all arc files
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/arc uses of the __cpuinit macros from
all C files.  Currently arc does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:37:58 +05:30
Vineet Gupta dc81df2440 ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNT
LOAD_FAULT_PTE macro is expected to set r2 with faulting vaddr.
However in case of CONFIG_ARC_DBG_TLB_MISS_COUNT, it was getting
clobbered with statistics collection code.

Fix latter by using a different register.

Note that only I-TLB Miss handler was potentially affected.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:37:57 +05:30
Vineet Gupta c3e757a77c ARC: [tlb-miss] Extraneous PTE bit testing/setting
* No need to check for READ access in I-TLB Miss handler

* Redundant PAGE_PRESENT update in PTE

Post TLB entry installation, in updating PTE for software accessed/dity
bits, no need to update PAGE_PRESENT since it will already be set.
Infact the entry won't have installed if !PAGE_PRESENT.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:37:57 +05:30
Vineet Gupta 5a45da02cf ARC: Adjustments for gcc 4.8
* DWARF unwinder related
  + Force DWARF2 compliant .debug_frame (gcc 4.8 defaults to DWARF4
    which kernel unwinder can't grok).
  + Discard the additional .eh_frame generated
  + Discard the dwarf4 debug info generated by -gdwarf-2 for normal
    no debug case

* 4.8 already uses arc600 multilibs for -mno-mpy

* switch to using uclibc compiler (to get -mmedium-calls and -mno-sdata)
  and also since buildroot can only use 1 toolchain

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:35:32 +05:30
Christian Ruppert 9803f86894 i2c-designware: make SDA hold time configurable
This patch makes the SDA hold time configurable through device tree.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com> for arch/arc bits
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-26 16:02:06 +02:00
Vineet Gupta 05b016ecf5 ARC: Setup Vector Table Base in early boot
Otherwise early boot exceptions such as instructions errors due to
configuration mismatch between kernel and hardware go off to la-la land,
as opposed to hitting the handler and panic()'ing properly.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-26 15:30:51 +05:30
Vineet Gupta 38a9ff6d24 ARC: Remove explicit passing around of ECR
With ECR now part of pt_regs

* No need to propagate from lowest asm handlers as arg
* No need to save it in tsk->thread.cause_code
* Avoid bit chopping to access the bit-fields

More code consolidation, cleanup

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-26 15:30:50 +05:30
Vineet Gupta 502a0c775c ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
pt_regs->event was set with artificial values to identify the low level
system event (syscall trap / breakpoint trap / exceptions / interrupts)

With r8 saving out of the way, the full word can be used to save real
ECR (Exception Cause Register) which helps idenify the event naturally,
including additional info such as cause code, param.
Only for Interrupts, where ECR is not applicable, do we resort to
synthetic non ECR values.

SAVE_ALL_TRAP/EXCEPTIONS can now be merged as they both use ECR with
different runtime values.

The ptrace helpers now use the sub-fields of ECR to distinguish the
events (e.g. vector 0x25 is trap, param 0 is syscall...)

The following benefits will follow:

(1) This centralizes the location of where ECR is saved and will allow
    the cleanup of task->thread.cause_code ECR placeholder which is set
    in non-uniform way. Then ARC VM code can safely rely on it being
    there for purpose of finer grained VM_EXEC dcache flush (based on
    exec fault: I-TLB Miss)

(2) Further, ECR being passed around from low level handlers as arg can
    be eliminated as it is part of standard reg-file in pt_regs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-26 14:04:48 +05:30
Vineet Gupta 352c1d95e3 ARC: stop using pt_regs->orig_r8
Historically, pt_regs have had orig_r8, an overloaded container for
  (1) backup copy of r8 (syscall number Trap Exceptions)
  (2) additional system state: (syscall/Exception/Interrupt)

There is no point in keeping (1) since syscall number is never clobbered
in-place, in pt_regs, unlike r0 which duals as first syscall arg as well
as syscall return value and in case of syscall restart, the orig arg0
needs restoring (from orig_r0)  after having been updated in-place with
syscall ret value.

This further paves way to convert (2) to contain ECR itself (rather than
current madeup values)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:26 +05:30
Vineet Gupta 359105bdb0 ARC: pt_regs update #4: r25 saved/restored unconditionally
(This is a VERY IMP change for low level interrupt/exception handling)

-----------------------------------------------------------------------
WHAT
-----------------------------------------------------------------------
* User 25 now saved in pt_regs->user_r25 (vs. tsk->thread_info.user_r25)

* This allows Low level interrupt code to unconditionally save r25
  (vs. the prev version which would only do it for U->K transition).
  Ofcourse for nested interrupts, only the pt_regs->user_r25 of
  bottom-most frame is useful.

* simplifies the interrupt prologue/epilogue

* Needed for ARCv2 ISA code and done here to keep design similar with
  ARCompact event handling

-----------------------------------------------------------------------
WHY
-------------------------------------------------------------------------
With CONFIG_ARC_CURR_IN_REG, r25 is used to cache "current" task pointer
in kernel mode. So when entering kernel mode from User Mode
- user r25 is specially safe-kept (it being a callee reg is NOT part of
  pt_regs which are saved by default on each interrupt/trap/exception)
- r25 loaded with current task pointer.

Further, if interrupt was taken in kernel mode, this is skipped since we
know that r25 already has valid "current" pointer.

With 2 level of interrupts in ARCompact ISA, detecting this is difficult
but still possible, since we could be in kernel mode but r25 not already saved
(in fact the stack itself might not have been switched).

A. User mode
B. L1 IRQ taken
C. L2 IRQ taken (while on 1st line of L1 ISR)

So in #C, although in kernel mode, r25 not saved (infact SP not
switched at all)

Given that ARcompact has manual stack switching, we could use a bit of
trickey - The low level code would make sure that SP is only set to kernel
mode value at the very end (after saving r25). So a non kernel mode SP,
even if in kernel mode, meant r25 was NOT saved.

The same paradigm won't work in ARCv2 ISA since SP is auto-switched so
it's setting can't be delayed/constrained.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:25 +05:30
Vineet Gupta ba3558c772 ARC: K/U SP saved from one location in stack switching macro
This paves way for further simplifications.

There's an overhead of 1 insn for the non-common case of interrupt taken
from kernel mode.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:25 +05:30
Vineet Gupta 147aece29b ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:24 +05:30
Vineet Gupta 1898a959b7 ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:23 +05:30
Vineet Gupta 3ebedbb2fd ARC: Increase readability of entry handlers
* use artificial PUSH/POP contructs for CORE Reg save/restore to stack
* use artificial PUSHAX/POPAX contructs for Auxiliary Space regs
* macro'ize multiple copies of callee-reg-save/restore (SAVE_R13_TO_R24)
* use BIC insn for inverse-and operation

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:23 +05:30
Vineet Gupta 16f9afe651 ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
This is trickier than prev two:

* context switching code saves kernel mode callee regs in the format of
  struct callee_regs thus needs adjustment. This also reduces the height
  of topmost kernel stack frame by 1 word.

* Since kernel stack unwinder is sensitive to height of topmost kernel
  stack frame, that needs a word of adjustment too.

ptrace needs a bit of updating since pt_regs now diverges from
user_regs_struct.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:22 +05:30
Vineet Gupta 2fa919045b ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:22 +05:30
Vineet Gupta 283237a04f ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
Historically, pt_regs would end at offset of 1 word from end of stack
page.

        -----------------  -> START of page (task->stack)
        |               |
        | thread_info   |
        -----------------
        |               |
   ^    ~               ~
   |    ~               ~
   |    |               |
   |    |               | <---- pt_regs used to END here
        -----------------
        | 1 word GUTTER |
        ----------------- -> End of page (START of kernel stack)

This required special "one-off" considerations in low level code.

The root cause is very likely assumption of "empty" SP by the original
ARC kernel hackers, despite ARC700 always been "full" SP.

So finally RIP one word gutter !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:21 +05:30
Vineet Gupta bed30976e7 ARC: pt_regs update #0: remove kernel stack canary
This stack slot is going to be used in subsequent commits

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:21 +05:30
Vineet Gupta 3e1ae44188 ARC: [mm] Remove @write argument to do_page_fault()
This can be ascertained within do_page_fault() since it gets the full
ECR (Exception Cause Register).

Further, for both the callers of do_page_fault(): Prot-V / D-TLB-Miss,
the cause sub-fields in ECR are same for same type of access, making the
code much more simpler.

D-TLB-Miss [LD] 0x00_21_01_00
Prot-V     [LD] 0x00_23_01_00
                        ^^
D-TLB-Miss [ST] 0x00_21_02_00
Prot-V     [ST] 0x00_23_02_00
                        ^^
D-TLB-Miss [EX] 0x00_21_03_00
Prot-V     [EX] 0x00_23_03_00
                        ^^

This helps code consolidation, which is even better when moving code from
assembler to "C".

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:20 +05:30
Vineet Gupta 3abc944802 ARC: [mm] Make stack/heap Non-executable by default
1. For VM_EXEC based delayed dcache/icache flush, reduces the number of
   flushes.

2. Makes this security feature ON by default rather than OFF before.

3. Applications can use mprotect() to selectively override this.

4. ELF binaries have a GNU_STACK segment which can easily override the
   kernel default permissions.
   For nested-functions/trampolines, gcc already auto-enables executable
   stack in elf. Others needing this can use -Wl,-z,execstack option.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:20 +05:30
Vineet Gupta 2ed21dae02 ARC: [mm] Assume pagecache page dirty by default
Similar to ARM/SH

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:19 +05:30
Vineet Gupta fedf5b9baf ARC: [mm] optimise VIPT dcache aliasing 2/x
Non-congruent SRC page in copy_user_page() is dcache clean in the end -
so record that fact, to avoid a subsequent extraneous flush.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:19 +05:30
Vineet Gupta 5971bc719d ARC: [mm] optimise VIPT dcache aliasing 1/x
flush_cache_page() - kills icache only if page is executable

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:18 +05:30
Vineet Gupta 29b93c68bf ARC: [mm] Zero page optimization
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:18 +05:30
Alexey Brodkin 2f9e99618f ARC: make dcache VIPT aliasing support dependant on dcache
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:17 +05:30
Vineet Gupta 336e199e9c ARC: No-op full icache flush if !CONFIG_ARC_HAS_ICACHE
Also remove extraneous irq disabling in flush_cache_all() callstack

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:22:42 +05:30
Vineet Gupta 3049918660 ARC: cache detection code bitrot
* Number of (i|d)cache ways can be retrieved from BCRs and hence no need
  to cross check with with built-in constants
* Use of IS_ENABLED() to check for a Kconfig option
* is_not_cache_aligned() not used anymore

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:43 +05:30
Vineet Gupta 6546415226 ARC: Reduce Code for ECR printing
Cause codes are same for D-TLB-Miss and Prot-V

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Vineet Gupta da1677b02d ARC: Disintegrate arcregs.h
* Move the various sub-system defines/types into relevant files/functions
  (reduces compilation time)

* move CPU specific stuff out of asm/tlb.h into asm/mmu.h

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Vineet Gupta 18437347b9 ARC: More code beautification with IS_ENABLED()
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Vineet Gupta 8235703e10 ARC: Use kconfig helper IS_ENABLED() to get rid of defines.h
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Mischa Jonker ba5afadb11 ARC: [plat-arcfpga] Fix build breakage when !CONFIG_ARC_SERIAL
This fixes the following:
- CONFIG_ARC_SERIAL_BAUD is only defined when CONFIG_SERIAL_ARC is defined.
  Make sure that it isn't referenced otherwise.
- There is no use for initializing arc_uart_info[] when CONFIG_SERIAL_ARC is
  not defined.

[vgupta: tweaked changelog title, used IS_ENABLED() kconfig helper]
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:41 +05:30
Vineet Gupta 7bb66f6e6e ARC: lazy dcache flush broke gdb in non-aliasing configs
gdbserver inserting a breakpoint ends up calling copy_user_page() for a
code page. The generic version of which (non-aliasing config) didn't set
the PG_arch_1 bit hence update_mmu_cache() didn't sync dcache/icache for
corresponding dynamic loader code page - causing garbade to be executed.

So now aliasing versions of copy_user_highpage()/clear_page() are made
default. There is no significant overhead since all of special alias
handling code is compiled out for non-aliasing build

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-25 14:15:55 +05:30
Vineet Gupta 006dfb3c9c ARC: Use enough bits for determining page's cache color
The current code uses 2 bits for determining page's dcache color, thus
sorting pages into 4 bins, whereas the aliasing dcache really has 2 bins
(8k page, 64k dcache - 4 way-set-assoc).
This can cause extraneous flushes - e.g. color 0 and 2.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 14:25:09 +05:30
Vineet Gupta 3e87974dec ARC: Brown paper bag bug in macro for checking cache color
The VM_EXEC check in update_mmu_cache() was getting optimized away
because of a stupid error in definition of macro addr_not_cache_congruent()

The intention was to have the equivalent of following:

	if (a || (1 ? b : 0))

but we ended up with following:

	if (a || 1 ? b : 0)

And because precedence of '||' is more that that of '?', gcc was optimizing
away evaluation of <a>

Nasty Repercussions:
1. For non-aliasing configs it would mean some extraneous dcache flushes
   for non-code pages if U/K mappings were not congruent.
2. For aliasing config, some needed dcache flush for code pages might
   be missed if U/K mappings were congruent.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 14:24:52 +05:30
Vineet Gupta a950549c67 ARC: copy_(to|from)_user() to honor usermode-access permissions
This manifested as grep failing psuedo-randomly:

-------------->8---------------------
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$
[ARCLinux]$ ip address show lo | grep inet
    inet 127.0.0.1/8 scope host lo
-------------->8---------------------

ARC700 MMU provides fully orthogonal permission bits per page:
Ur, Uw, Ux, Kr, Kw, Kx

The user mode page permission templates used to have all Kernel mode
access bits enabled.
This caused a tricky race condition observed with uClibc buffered file
read and UNIX pipes.

1. Read access to an anon mapped page in libc .bss: write-protected
   zero_page mapped: TLB Entry installed with Ur + K[rwx]

2. grep calls libc:getc() -> buffered read layer calls read(2) with the
   internal read buffer in same .bss page.
   The read() call is on STDIN which has been redirected to a pipe.
   read(2) => sys_read() => pipe_read() => copy_to_user()

3. Since page has Kernel-write permission (despite being user-mode
   write-protected), copy_to_user() suceeds w/o taking a MMU TLB-Miss
   Exception (page-fault for ARC). core-MM is unaware that kernel
   erroneously wrote to the reserved read-only zero-page (BUG #1)

4. Control returns to userspace which now does a write to same .bss page
   Since Linux MM is not aware that page has been modified by kernel, it
   simply reassigns a new writable zero-init page to mapping, loosing the
   prior write by kernel - effectively zero'ing out the libc read buffer
   under the hood - hence grep doesn't see right data (BUG #2)

The fix is to make all kernel-mode access permissions mirror the
user-mode ones. Note that the kernel still has full access to pages,
when accessed directly (w/o MMU) - this fix ensures that kernel-mode
access in copy_to_from() path uses the same faulting access model as for
pure user accesses to keep MM fully aware of page state.

The issue is peudo-random because it only shows up if the TLB entry
installed in #1 is present at the time of #3. If it is evicted out, due
to TLB pressure or some-such, then copy_to_user() does take a TLB Miss
Exception, with a routine write-to-anon COW processing installing a
fresh page for kernel writes and also usable as it is in userspace.

Further the issue was dormant for so long as it depends on where the
libc internal read buffer (in .bss) is mapped at runtime.
If it happens to reside in file-backed data mapping of libc (in the
page-aligned slack space trailing the file backed data), loader zero
padding the slack space, does the early cow page replacement, setting
things up at the very beginning itself.

With gcc 4.8 based builds, the libc buffer got pushed out to a real
anon mapping which triggers the issue.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Cc: <stable@vger.kernel.org> # 3.9
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 10:33:03 +05:30
Vineet Gupta f538881cc6 ARC: [mm] Prevent stray dcache lines after__sync_icache_dcach()
Flush and INVALIDATE the dcache page.

This helper is only used for writeback of CODE pages to memory. So
there's no value in keeping the dcache lines around. Infact it is risky
as a writeback on natural eviction under pressure can cause un-needed
writeback with weird issues on aliasing dcache configurations.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 10:26:33 +05:30
Christian Ruppert 7d19273cd0 ARC: [TB10x] Remove redundant abilis,simple-pinctrl mechanism
The TB10x platform port includes a custom mechanism using to set up
default pin controller configurations using abilis,simple-default
pin configurations of nodes compatible with abilis,simple-pinctrl. This
mechanism is redundant with the Linux standard "default" pin
configuration, see commit ab78029ecc
"drivers/pinctrl: grab default handles from device core".
This patch removes the TB10x custom mechanism in favour of the Linux
standard.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-15 10:12:03 +05:30
Linus Torvalds 6019958d14 Aliasing VIPT dcache support for ARC
I'm satisified with testing, specially with fuse which has historically given
 grief to VIPT arches (ARM/PARISC...)
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Merge tag 'arc-v3.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull second set of arc arch updates from Vineet Gupta:
 "Aliasing VIPT dcache support for ARC

  I'm satisified with testing, specially with fuse which has
  historically given grief to VIPT arches (ARM/PARISC...)"

* tag 'arc-v3.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [TB10x] Remove GENERIC_GPIO
  ARC: [mm] Aliasing VIPT dcache support 4/4
  ARC: [mm] Aliasing VIPT dcache support 3/4
  ARC: [mm] Aliasing VIPT dcache support 2/4
  ARC: [mm] Aliasing VIPT dcache support 1/4
  ARC: [mm] refactor the core (i|d)cache line ops loops
  ARC: [mm] serious bug in vaddr based icache flush
2013-05-10 07:24:14 -07:00
Vineet Gupta e7d5bab5ef ARC: [TB10x] Remove GENERIC_GPIO
This tracks Alexandre Courbot's mainline GPIO rework

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
2013-05-10 09:50:33 +05:30
Linus Torvalds e30f419245 ARC port updates for Linux 3.10 (part 1)
* Support for two new platforms based on ARC700
  - Abilis TB10x SoC [Chritisian/Pierrick]
  - Simulator only System-C Model [Mischa]
 
 * ARC specific MM improvements
  - Avoid full TLB flush (ASID increment) on munmap (even single page)
  - VIPT Cache Flushing improvements
    + Delayed dcache flush for non-aliasing dcache (big performance boost)
    + icache flush aliasing agnostic (no need to kill all possible aliases)
 
 * Others
  - Avoid needless rebuild of DTB files for every kernel build
  - Remove builtin cmdline as that is already provided by DeviceTree/bootargs
  - Fixing unaligned access emulation corner case
  - checkpatch fixes [Sachin]
  - Various fixlets [Noam]
  - Minor build failures/cleanups
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Merge tag 'arc-v3.10-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC port updates from Vineet Gupta:
 "Support for two new platforms based on ARC700:
   - Abilis TB10x SoC [Chritisian/Pierrick]
   - Simulator only System-C Model [Mischa]

  ARC specific MM improvements:
   - Avoid full TLB flush (ASID increment) on munmap (even single page)
   - VIPT Cache Flushing improvements
     + Delayed dcache flush for non-aliasing dcache (big performance boost)
     + icache flush aliasing agnostic (no need to kill all possible aliases)

  Others:
   - Avoid needless rebuild of DTB files for every kernel build
   - Remove builtin cmdline as that is already provided by DeviceTree/bootargs
   - Fixing unaligned access emulation corner case
   - checkpatch fixes [Sachin]
   - Various fixlets [Noam]
   - Minor build failures/cleanups"

* tag 'arc-v3.10-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (35 commits)
  ARC: [mm] Lazy D-cache flush (non aliasing VIPT)
  ARC: [mm] micro-optimize page size icache invalidate
  ARC: [mm] remove the pessimistic all-alias-invalidate icache helpers
  ARC: [mm] consolidate icache/dcache sync code
  ARC: [mm] optimise icache flush for kernel mappings
  ARC: [mm] optimise icache flush for user mappings
  ARC: [mm] optimize needless full mm TLB flush on munmap
  ARC: Add support for nSIM OSCI System C model
  ARC: [TB10x] Adapt device tree to new compatible string
  ARC: [TB10x] Add support for TB10x platform
  ARC: [TB10x] Device tree of TB100 and TB101 Development Kits
  ARC: Prepare interrupt code for external controllers
  ARC: Allow embedded arc-intc to be properly placed in DT intc hierarchy
  ARC: [cmdline] Don't overwrite u-boot provided bootargs
  ARC: [cmdline] Remove CONFIG_CMDLINE
  ARC: [plat-arcfpga] defconfig update
  ARC: unaligned access emulation broken if callee-reg dest of LD/ST
  ARC: unaligned access emulation error handling consolidation
  ARC: Debug/crash-printing Improvements
  ARC: fix typo with clock speed
  ...
2013-05-09 14:36:27 -07:00
Vineet Gupta 5bba49f539 ARC: [mm] Aliasing VIPT dcache support 4/4
Enforce congruency of userspace shared mappings

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 22:00:57 +05:30
Vineet Gupta de2a852cc0 ARC: [mm] Aliasing VIPT dcache support 3/4
Fix the one zillion warnings

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 22:00:57 +05:30
Vineet Gupta 4102b53392 ARC: [mm] Aliasing VIPT dcache support 2/4
This is the meat of the series which prevents any dcache alias creation
by always keeping the U and K mapping of a page congruent.
If a mapping already exists, and other tries to access the page, prev
one is flushed to physical page (wback+inv)

Essentially flush_dcache_page()/copy_user_highpage() create K-mapping
of a page, but try to defer flushing, unless U-mapping exist.
When page is actually mapped to userspace, update_mmu_cache() flushes
the K-mapping (in certain cases this can be optimised out)

Additonally flush_cache_mm(), flush_cache_range(), flush_cache_page()
handle the puring of stale userspace mappings on exit/munmap...

flush_anon_page() handles the existing U-mapping for anon page before
kernel reads it via the GUP path.

Note that while not complete, this is enough to boot a simple
dynamically linked Busybox based rootfs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 21:59:46 +05:30
Vineet Gupta 6ec18a81b2 ARC: [mm] Aliasing VIPT dcache support 1/4
This preps the low level dcache flush helpers to take vaddr argument in
addition to the existing paddr to properly flush the VIPT dcache

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 21:53:16 +05:30
Vineet Gupta a690984d60 ARC: [mm] refactor the core (i|d)cache line ops loops
Nothing semantical
* simplify the alignement code by using & operation only
* rename variables clearly as paddr

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 14:18:50 +05:30
Vineet Gupta c917a36f5f ARC: [mm] serious bug in vaddr based icache flush
vaddr used to index the cache was clipped from the wrong end, and thus
would potentially fail to flush the correct lines.

The problem was dorment for so long because up until the recent
optimizations it was only used for ptrace break-point only flushes.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 13:45:12 +05:30
Vineet Gupta eacd0e950d ARC: [mm] Lazy D-cache flush (non aliasing VIPT)
flush_dcache_page( ) is MM hook to ensure that a page has consistent
views between kernel and userspace. Thus it is called when

* kernel writes to a page which at some later point could get mapped to
  userspace (so kernel mapping needs to be flushed-n-inv)
* kernel is about to read from a page with possible userspace mappings
  (so userspace mappings needs to be made coherent with kernel ones)

However for Non aliasing VIPT dcache, any userspace mapping will always
be congruent to kernel mapping. Thus d-cache need need not be flushed at
all (or delayed indefinitely).

The only reason it does need to be flushed is when mapping code pages.
Since icache doesn't snoop dcache, those dirty dcache lines need to be
written back to memory and icache line invalidated so that icache lines
fetch will get the right data.

Decent gains on LMBench fork/exec/sh and File I/O micro-benchmarks.

(1) FPGA @ 80 MHZ

Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
3.9-rc6-a Linux 3.9.0-r   80 4.79 8.72 66.7 116. 239. 8.39 30.4 4798 14.K 34.K
3.9-rc6-b Linux 3.9.0-r   80 4.79 8.62 65.4 111. 239. 8.35 29.0 3995 12.K 30.K
3.9-rc7-c Linux 3.9.0-r   80 4.79 9.00 66.1 106. 239. 8.61 30.4 2858 10.K 24.K
                                                                ^^^^ ^^^^ ^^^

File & VM system latencies in microseconds - smaller is better
-------------------------------------------------------------------------------
Host                 OS   0K File      10K File     Mmap    Prot   Page 100fd
                        Create Delete Create Delete Latency Fault  Fault selct
--------- ------------- ------ ------ ------ ------ ------- ----- ------- -----
3.9-rc6-a Linux 3.9.0-r  317.8  204.2 1122.3  375.1 3522.0 4.288     20.7 126.8
3.9-rc6-b Linux 3.9.0-r  298.7  223.0 1141.6  367.8 3531.0 4.866     20.9 126.4
3.9-rc7-c Linux 3.9.0-r  278.4  179.2  862.1  339.3 3705.0 3.223     20.3 126.6
                         ^^^^^  ^^^^^  ^^^^^  ^^^^

(2) Customer Silicon @ 500 MHz (166 MHz mem)

------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
abilis-ba Linux 3.9.0-r  497 0.71 1.38 4.58 12.0 35.5 1.40 3.89 2070 5525 13.K
abilis-ca Linux 3.9.0-r  497 0.71 1.40 4.61 11.8 35.6 1.37 3.92 1411 4317 10.K
                                                                ^^^^ ^^^^ ^^^

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:15 +05:30
Vineet Gupta 764531cc5a ARC: [mm] micro-optimize page size icache invalidate
start address is already page aligned and size is const PAGE_SIZE,
thus fixups for alignment not needed in generated code.

bloat-o-meter vmlinux-mm5 vmlinux
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-32 (-32)
function                                     old     new   delta
__inv_icache_page                             82      50     -32

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:14 +05:30
Vineet Gupta 7f250a0fa1 ARC: [mm] remove the pessimistic all-alias-invalidate icache helpers
No users of this code anymore - so RIP !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:13 +05:30
Vineet Gupta 94bad1afee ARC: [mm] consolidate icache/dcache sync code
Now that we have same helper used for all icache invalidates (i.e.
vaddr+paddr based exact line invalidate), consolidate the open coded
calls into one place.

Also rename flush_icache_range_vaddr => __sync_icache_dcache

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:13 +05:30
Vineet Gupta 7586bf7286 ARC: [mm] optimise icache flush for kernel mappings
This change continues the theme from prev commit - this time icache
handling for kernel's own code modification (vmalloc: loadable modules,
breakpoints for kprobes/kgdb...)

flush_icache_range() calls the CDU icache helper with vaddr to enable
exact line invalidate.

For a true kernel-virtual mapping, the vaddr is actually virtual hence
valid as index into cache. For kprobes breakpoint however, the vaddr arg
is actually paddr - since that's how normal kernel is mapped in ARC
memory map.  This implies that CDU will use the same addr for
indexing as for tag match - which is fine since kernel code would only
have that "implicit" mapping and none other.

This should speed up module loading significantly - specially on default
ARC700 icache configurations (32k) which alias.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:12 +05:30
Vineet Gupta 24603fdd19 ARC: [mm] optimise icache flush for user mappings
ARC icache doesn't snoop dcache thus executable pages need to be made
coherent before mapping into userspace in flush_icache_page().

However ARC700 CDU (hardware cache flush module) requires both vaddr
(index in cache) as well as paddr (tag match) to correctly identify a
line in the VIPT cache. A typical ARC700 SoC has aliasing icache, thus
the paddr only based flush_icache_page() API couldn't be implemented
efficiently. It had to loop thru all possible alias indexes and perform
the invalidate operation (ofcourse the cache op would only succeed at
the index(es) where tag matches - typically only 1, but the cost of
visiting all the cache-bins needs to paid nevertheless).

Turns out however that the vaddr (along with paddr) is available in
update_mmu_cache() hence better suits ARC icache flush semantics.
With both vaddr+paddr, exactly one flush operation per line is done.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:12 +05:30
Vineet Gupta 8d56bec2f2 ARC: [mm] optimize needless full mm TLB flush on munmap
munmap ends up calling tlb_flush() which for ARC was flushing the entire
TLB unconditionally (by moving the MMU to a new ASID)

do_munmap
  unmap_region
    unmap_vmas
      unmap_single_vma
         unmap_page_range
            tlb_start_vma
            zap_pud_range
            tlb_end_vma()
  tlb_finish_mmu
    tlb_flush()  ---> unconditional flush_tlb_mm()

So even a single page munmap, a frequent operation when uClibc dynamic
linker (ldso) is loading the dependent shared libraries, would move the
the ASID multiple times - needlessly invalidating the pre-faulted TLB
entries (and increasing the rate of ASID wraparound + full TLB flush).

This is now optimised to only be called if tlb->full_mm (which means
for exit/execve) cases only. And for those cases, flush_tlb_mm() is
already optimised to be a no-op for mm->mm_users == 0.

So essentially there are no mmore full mm flushes - except for fork which
anyhow needs it for properly COW'ing parent address space.

munmap now needs to do TLB range flush, which is implemented with
tlb_end_vma()

Results
-------
1. ASID now consistenly moves by 4 during a simple ls (as opposed to 5 or
   7 before).

2. LMBench microbenchmark also shows improvements

Basic system parameters
------------------------------------------------------------------------------
Host                 OS Description              Mhz  tlb  cache  mem scal
                                                     pages line   par load
                                                           bytes
--------- ------------- ----------------------- ---- ----- ----- ------ ----
3.9-rc5-0 Linux 3.9.0-r 3.9-rc5-0404-gcc-4.4-ba   80     8    64 1.1000 1
3.9-rc5-0 Linux 3.9.0-r 3.9-rc5-0405-avoid-full   80     8    64 1.1200 1

Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
3.9-rc5-0 Linux 3.9.0-r   80 4.81 8.69 68.6 118. 239. 8.53 31.6 4839 13.K 34.K
3.9-rc5-0 Linux 3.9.0-r   80 4.46 8.36 53.8 91.3 223. 8.12 24.2 4725 13.K 33.K

File & VM system latencies in microseconds - smaller is better
-------------------------------------------------------------------------------
Host                 OS   0K File      10K File     Mmap    Prot   Page 100fd
                        Create Delete Create Delete Latency Fault  Fault selct
--------- ------------- ------ ------ ------ ------ ------- ----- ------- -----
3.9-rc5-0 Linux 3.9.0-r  314.7  223.2 1054.9  390.2  3615.0 1.590 20.1 126.6
3.9-rc5-0 Linux 3.9.0-r  265.8  183.8 1014.2  314.1  3193.0 6.910 18.8 110.4

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:44:00 +05:30
Mischa Jonker a92a5d0dce ARC: Add support for nSIM OSCI System C model
This adds support for an ARC Virtual Platform. This platform is based on the
System C standard promoted by the OSCI (Open System C Initiative) and uses
nSIM to simulate the ARC CPU core itself.

Users can build a virtual SoC by combining System C models of peripherals
and CPU cores.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:44:00 +05:30
Christian Ruppert 0dfad77d0a ARC: [TB10x] Adapt device tree to new compatible string
The original device tree was written using a slightly different
implementation of the fixed-factor-clock device tree binding. The
compatible string must be modified in order to be compatible with the
new implementation.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:59 +05:30
Christian Ruppert 072eb69390 ARC: [TB10x] Add support for TB10x platform
Infrastructure required to make the Linux kernel compile and boot on the
Abilis Systems TB10x series of SOCs based on ARC700 CPUs:
  - Kmake related files (Kconfig, Makefile, tb10x_defconfig)
  - TB10x platform initialisation

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:59 +05:30
Christian Ruppert 2eb9504bcc ARC: [TB10x] Device tree of TB100 and TB101 Development Kits
These are the device tree files for the Abilis Systems TB100 and TB101 ICs and
their respective development kit PCBs. These files are committed in preparation
of the following patch set which adds support for these chips to the ARC
platform.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:58 +05:30
Christian Ruppert a37cdacc9b ARC: Prepare interrupt code for external controllers
This patch adds some room for CPU-external interrupt controllers in the
Linux interrupt space. Until now, only the 32 CPU internal interrupt lines
were supported which does not allow for external interrupt controllers such
as GPIO modules etc.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:58 +05:30
Vineet Gupta c93d8b8c78 ARC: Allow embedded arc-intc to be properly placed in DT intc hierarchy
arc-intc is initialized in arc common code as it is applicable to all
platforms. However platforms with their own external intc still need to
refer to it for correct DT interrupt tree hierarchy setup,

e.g.
static struct of_device_id __initdata tb10x_irq_ids[] = {
	{ .compatible = "snps,arc700-intc", .data = dummy_init_irq },
	{ .compatible = "abilis,tb10x_ictl", .data = tb10x_init_irq },
	{},
};

The fix is to use the generic irqchip framework to tie all irqchips in
a special linker section and then call irqchip_init() which calls the
DT of_irq_init() for all the intc in one go.

That way the platform code need not be aware of arc-intc at all.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:57 +05:30
Vineet Gupta 9593a933d5 ARC: [cmdline] Don't overwrite u-boot provided bootargs
The existing code was wrong on several counts:

* uboot provided bootargs were copied into @boot_command_line, only to
  be over-written by setup_machine_fdt(), effectively lost

* @cmdline_p returned by setup_arch() to start_kernel() didn't include
  the DT /bootargs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:57 +05:30
Vineet Gupta 6971881f2a ARC: [cmdline] Remove CONFIG_CMDLINE
Given that DeviceTree /bootargs can provide similar functionality,
no point in providing duplicate infrastructure.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:56 +05:30
Vineet Gupta 330db3330a ARC: [plat-arcfpga] defconfig update
* Allow initramfs path to be symlink
* CONFIG_PREEMPT be default

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:56 +05:30
Vineet Gupta ce147c7445 ARC: unaligned access emulation broken if callee-reg dest of LD/ST
The fixup code correctly updates the callee-regs on stack, but
fails to unwind it into actual register file. Thus userspace won't see
the update.

Reported-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:55 +05:30
Vineet Gupta c723ea4620 ARC: unaligned access emulation error handling consolidation
If CONFIG_ARC_MISALIGN_ACCESS is not enabled, or if the fixup fails,
call the same error handler: same signal/si_code to user (SIGBUS)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:55 +05:30
Vineet Gupta bd3c8b11ec ARC: Debug/crash-printing Improvements
* Remove the line-break between scratch/callee-regs (sneaked in when we
  converted from printk to pr_*

* Use %pS to print the symbol names of faulting PC (ret pseudo register)
  and BLINK (call return register)

* Don't print user-vma for a kernel crash (only do it for
  print-fatal-signals based regfile dump)

* Verbose print the Interrupt/Exception Enable/Active state

* for main executable link address is 0x10000 based (vs. 0) thus offset
  of faulting PC needs to be adjusted

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Noam Camus 68e4790ec4 ARC: fix typo with clock speed
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Noam Camus e3edeb67fb ARC: Respect the cpu_id passed for fetching correct cpu info
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Alexander Shiyan 0e82284514 ARC: Remove non existent refs to GENERIC_KERNEL_EXECVE & GENERIC_KERNEL_THREAD
This tracks mainline commit ae903caae2 "Bury the conditionals from
kernel_thread/kernel_execve series" which we missed out as ARC port was
not yet mainline.

[vgupta: commit log modified]

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:53 +05:30
Vineet Gupta 681a90ffe8 arc, print-fatal-signals: reduce duplicated information
After the recent generic debug info on dump_stack() and friends, arc
is printing duplicate information on debug dumps.

 [ARCLinux]$ ./crash
 crash/50: potentially unexpected fatal signal 11.	<-- [1]
 /sbin/crash, TGID 50					<-- [2]
 Pid: 50, comm: crash Not tainted 3.9.0-rc4+ #132 	<-- [3]
 ...

Remove them.

[tj@kernel.org: updated patch desc]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Tejun Heo a43cb95d54 dump_stack: unify debug information printed by show_regs()
show_regs() is inherently arch-dependent but it does make sense to print
generic debug information and some archs already do albeit in slightly
different forms.  This patch introduces a generic function to print debug
information from show_regs() so that different archs print out the same
information and it's much easier to modify what's printed.

show_regs_print_info() prints out the same debug info as dump_stack()
does plus task and thread_info pointers.

* Archs which didn't print debug info now do.

  alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
  metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
  um, xtensa

* Already prints debug info.  Replaced with show_regs_print_info().
  The printed information is superset of what used to be there.

  arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86

* s390 is special in that it used to print arch-specific information
  along with generic debug info.  Heiko and Martin think that the
  arch-specific extra isn't worth keeping s390 specfic implementation.
  Converted to use the generic version.

Note that now all archs print the debug info before actual register
dumps.

An example BUG() dump follows.

 kernel BUG at /work/os/work/kernel/workqueue.c:4841!
 invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
 RIP: 0010:[<ffffffff8234a07e>]  [<ffffffff8234a07e>] init_workqueues+0x4/0x6
 RSP: 0000:ffff88007c861ec8  EFLAGS: 00010246
 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
 RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Stack:
  ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
  0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
  ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
 Call Trace:
  [<ffffffff81000312>] do_one_initcall+0x122/0x170
  [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  [<ffffffff81c4776e>] kernel_init+0xe/0xf0
  [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  ...

v2: Typo fix in x86-32.

v3: CPU number dropped from show_regs_print_info() as
    dump_stack_print_info() has been updated to print it.  s390
    specific implementation dropped as requested by s390 maintainers.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>		[tile bits]
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Tejun Heo 196779b9b4 dump_stack: consolidate dump_stack() implementations and unify their behaviors
Both dump_stack() and show_stack() are currently implemented by each
architecture.  show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack().  On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.

The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().

There's no reason to require archs to implement two separate but mostly
identical functions.  It leads to unnecessary subtle information.

This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin.  Blackfin's
dump_stack() does something wonky that I don't understand.

Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information.  This is used
in blackfin.

This patch brings the following behavior changes.

* On some archs, an extra level in backtrace for show_stack() could be
  printed.  This is because the top frame was determined in
  dump_stack() on those archs while generic dump_stack() can't do that
  reliably.  It can be compensated by inlining dump_stack() but not
  sure whether that'd be necessary.

* Most archs didn't use to print debug info on dump_stack().  They do
  now.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Hardware name: empty
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a071>] init_workqueues+0x35/0x505
  ...

v2: CPU number added to the generic debug info as requested by s390
    folks and dropped the s390 specific dump_stack().  This loses %ksp
    from the debug message which the maintainers think isn't important
    enough to keep the s390-specific dump_stack() implementation.

    dump_stack_print_info() is moved to kernel/printk.c from
    lib/dump_stack.c.  Because linkage is per objecct file,
    dump_stack_print_info() living in the same lib file as generic
    dump_stack() means that archs which implement custom dump_stack()
    - at this point, only blackfin - can't use dump_stack_print_info()
    as that will bring in the generic version of dump_stack() too.  v1
    The v1 patch broke build on blackfin due to this issue.  The build
    breakage was reported by Fengguang Wu.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>	[s390 bits]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Linus Torvalds 5d434fcb25 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "Usual stuff, mostly comment fixes, typo fixes, printk fixes and small
  code cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (45 commits)
  mm: Convert print_symbol to %pSR
  gfs2: Convert print_symbol to %pSR
  m32r: Convert print_symbol to %pSR
  iostats.txt: add easy-to-find description for field 6
  x86 cmpxchg.h: fix wrong comment
  treewide: Fix typo in printk and comments
  doc: devicetree: Fix various typos
  docbook: fix 8250 naming in device-drivers
  pata_pdc2027x: Fix compiler warning
  treewide: Fix typo in printks
  mei: Fix comments in drivers/misc/mei
  treewide: Fix typos in kernel messages
  pm44xx: Fix comment for "CONFIG_CPU_IDLE"
  doc: Fix typo "CONFIG_CGROUP_CGROUP_MEMCG_SWAP"
  mmzone: correct "pags" to "pages" in comment.
  kernel-parameters: remove outdated 'noresidual' parameter
  Remove spurious _H suffixes from ifdef comments
  sound: Remove stray pluses from Kconfig file
  radio-shark: Fix printk "CONFIG_LED_CLASS"
  doc: put proper reference to CONFIG_MODULE_SIG_ENFORCE
  ...
2013-04-30 09:36:50 -07:00
Linus Torvalds 8700c95adb Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP/hotplug changes from Ingo Molnar:
 "This is a pretty large, multi-arch series unifying and generalizing
  the various disjunct pieces of idle routines that architectures have
  historically copied from each other and have grown in random, wildly
  inconsistent and sometimes buggy directions:

   101 files changed, 455 insertions(+), 1328 deletions(-)

  this went through a number of review and test iterations before it was
  committed, it was tested on various architectures, was exposed to
  linux-next for quite some time - nevertheless it might cause problems
  on architectures that don't read the mailing lists and don't regularly
  test linux-next.

  This cat herding excercise was motivated by the -rt kernel, and was
  brought to you by Thomas "the Whip" Gleixner."

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  idle: Remove GENERIC_IDLE_LOOP config switch
  um: Use generic idle loop
  ia64: Make sure interrupts enabled when we "safe_halt()"
  sparc: Use generic idle loop
  idle: Remove unused ARCH_HAS_DEFAULT_IDLE
  bfin: Fix typo in arch_cpu_idle()
  xtensa: Use generic idle loop
  x86: Use generic idle loop
  unicore: Use generic idle loop
  tile: Use generic idle loop
  tile: Enter idle with preemption disabled
  sh: Use generic idle loop
  score: Use generic idle loop
  s390: Use generic idle loop
  powerpc: Use generic idle loop
  parisc: Use generic idle loop
  openrisc: Use generic idle loop
  mn10300: Use generic idle loop
  mips: Use generic idle loop
  microblaze: Use generic idle loop
  ...
2013-04-30 07:50:17 -07:00
Jiang Liu d2309a1996 mm/arc: use common help functions to free reserved pages
Use common help functions to free reserved pages.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:31 -07:00
Vineet Gupta a89516b31c ARC: [kbuild] Avoid DTB rebuilds if DTS are untouched
Currently, for every ARC kernel build I see the following:

--------------->8-----------------
  DTB    arch/arc/boot/dts/angel4.dtb.S
  AS      arch/arc/boot/dts/angel4.dtb.o
  LD      arch/arc/boot/dts/built-in.o
rm arch/arc/boot/dts/angel4.dtb.S        <-- forces rebuild next iter
  CHK     kernel/config_data.h
--------------->8-----------------

This is because *.dts.S is intermediate file in dtb generation and is by
default deleted by make which needs a ".SECONDARY" hint to NOT do so.

This could have ideally been done in scripts/Makefile.lib - for benefit
of all, however .SECONDARY doesn't seem to work with wildcards.

Thanks to Stephen for suggesting .SECONDARY (vs .PRECIOUS) and making
that work using a non wildcard version in arch makefile.

Thanks to James Hogan for pointing out that *.dtb.S now needs to be
added to clean-files

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-17 18:19:14 +05:30
Thomas Gleixner d190e8195b idle: Remove GENERIC_IDLE_LOOP config switch
All archs are converted over. Remove the config switch and the
fallback code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17 10:39:38 +02:00
Vineet Gupta 5628832f4c ARC: [kbuild] Include Kconfig.binfmt
commit "fs: make binfmt support for #! scripts modular and removable"
made support for #!scripts optional - thus need to include the Kconfig
file to get all relevant BINFMT_*

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 17:27:01 +05:30
Vineet Gupta fbf8e13d31 ARC: [kbuild] Allow platforms to disable LLSC for !SMP as well
Currently ARC_HAS_LLSC can be influenced by platform for SMP only using
ARC_HAS_COH_LLSC. For !SMP it defaults to "y".

It turns out that some customers can't support it all, even in UP.
So we change the semantics, and use a negative dependency ARC_CANT_LLSC.
Any platform (independent of SMP or !SMP) can select it to disable LLSC.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 17:27:00 +05:30
Vineet Gupta 30ecee8cdd ARC: [build] Fix warnings with CONFIG_DEBUG_SECTION_MISMATCH
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 17:27:00 +05:30
Christian Ruppert 5b00029e30 ARC: [build] Build failure with !KPROBES
arch/arc/kernel/traps.c no longer compiles without explicitly including
asm/kprobes.h

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 17:26:50 +05:30
Vineet Gupta 104058ede7 ARC: [build] Allow uncompressed uImage
The existing uImage target always generates gzip compressed image which
drags bootup for some very slow FPGA customer boards.

So introduce seperate make targets:uImage.{bin,gz} with uncompressed
being default. Also tie gz generation to CONFIG_KERNEL_GZIP, which a
platform can select in it's Kconfig if it wishes gz to be default.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Vineet Gupta fb0990bbf5 ARC: [build] cleanup Makefile a bit
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Vineet Gupta af4c3ae399 ARC: [build] silence make defconfig warnings with host gcc 4.7
We do cross compiles for ARC Linux.
With gcc 4.7, a make defconfig spews out the following:

------------------->8--------------------------
make ARCH=arc defconfig
gcc: error: unrecognized command line option '-marc600'
gcc: error: unrecognized command line option '-mA7'
gcc: error: unrecognized command line option '-mno-sdata'
gcc: error: unrecognized command line option '-mno-mpy'
*** Default configuration is based on 'fpga_defconfig'
------------------->8--------------------------

This apparently is coming from LIBGCC line - which is strange to be
invoked for defconfig generation.

Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Paul Bolle 610c6502e0 ARC: remove #ifdef-ed out include of dead header
There's no (Kconfig) macro CONFIG_BLOCK_DEV_RAM. (CONFIG_BLK_DEV_RAM
does exist though.) But linux/blk.h got killed in 2005 anyway (in a
patch titled "kill blk.h"), so these three lines can be removed.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Sachin Kamat e420c82d09 ARC: Remove duplicate inclusion of header files
Some header files were included twice in the same file.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Sachin Kamat 955ad5959f ARC: Fix coding style issues
Fixes the following coding style issues as detected by checkpatch:
ERROR: space required before the open parenthesis '('
ERROR: "foo * bar" should be "foo *bar"
WARNING: space prohibited between function name and open parenthesis '('
WARNING: please, no spaces at the start of a line

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:14 +05:30
Sachin Kamat 1ec9db1056 ARC: Use <linux/*> headers instead of <asm/*>
Silences the following checkpatch warnings:
WARNING: Use #include <linux/ptrace.h> instead of <asm/ptrace.h>
WARNING: Use #include <linux/kprobes.h> instead of <asm/kprobes.h>
WARNING: Use #include <linux/kgdb.h> instead of <asm/kgdb.h>
WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
WARNING: Use #include <linux/cache.h> instead of <asm/cache.h>

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:14 +05:30
Sachin Kamat 39d0c30d00 ARC: Remove unneeded version.h header include
version.h header file inclusion is not necessary as detected by
versioncheck script.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:14 +05:30
Christian Ruppert 79e5f05edc ARC: Add implicit compiler barrier to raw_local_irq* functions
ARC irqsave/restore macros were missing the compiler barrier, causing a
stale load in irq-enabled region be used in irq-safe region, despite
being changed, because the register holding the value was still live.

The problem manifested as random crashes in timer code when stress
testing ARCLinux (3.9-rc3) on a !SMP && !PREEMPT_COUNT

Here's the exact sequence which caused this:
 (0). tv1[x] <----> t1 <---> t2
 (1). mod_timer(t1) interrupted after it calls timer_pending()
 (2). mod_timer(t2) completes
 (3). mod_timer(t1) resumes but messes up the list
 (4). __runt_timers( ) uses bogus timer_list entry / crashes in
      timer->function

Essentially mod_timer() was racing against itself and while the spinlock
serialized the tv1[] timer link list, timer_pending() called outside the
spinlock, cached timer link list element in a register.
With low register pressure (and a deep register file), lack of barrier
in raw_local_irqsave() as well as preempt_disable (!PREEMPT_COUNT
version), there was nothing to force gcc to reload across the spinlock,
causing a stale value in reg be used for link list manipulation - ensuing
a corruption.

ARcompact disassembly which shows the culprit generated code:

mod_timer:
    push_s blink
    mov_s r13,r0	# timer, timer
..
    ###### timer_pending( )
    ld_s r3,[r13]       # <------ <variable>.entry.next LOADED
    brne r3, 0, @.L163

.L163:
..
    ###### spin_lock_irq( )
    lr  r5, [status32]  # flags
    bic r4, r5, 6       # temp, flags,
    and.f 0, r5, 6      # flags,
    flag.nz r4

    ###### detach_if_pending( ) begins

    tst_s r3,r3  <--------------
			# timer_pending( ) checks timer->entry.next
                        # r3 is NOT reloaded by gcc, using stale value
    beq.d @.L169
    mov.eq r0,0

    #####  detach_timer( ): __list_del( )

    ld r4,[r13,4]    	# <variable>.entry.prev, D.31439
    st r4,[r3,4]     	# <variable>.prev, D.31439
    st r3,[r4]       	# <variable>.next, D.30246

We initially tried to fix this by adding barrier() to preempt_* macros
for !PREEMPT_COUNT but Linus clarified that it was anything but wrong.
http://www.spinics.net/lists/kernel/msg1512709.html

[vgupta: updated commitlog]

Reported-by/Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Debugged-by/Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-08 16:10:26 -07:00
Thomas Gleixner fa35e42a00 arc: Use generic idle loop
The generic idle loop implements all functionality. Aside of that it
allows arc to implement the tsk_is_polling() functionality correctly,
despite the patently (now gone) comment in the original arc cpu_idle()
function:
/* Since we SLEEP in idle loop, TIF_POLLING_NRFLAG can't be set */
See kernel/cpu/idle.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Tested-by: Vineet Gupta <vgupta@synopsys.com>
Link: http://lkml.kernel.org/r/20130321215233.711253792@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-08 17:39:23 +02:00
Vineet Gupta 367f3fcd92 ARC: Fix the typo in event identifier flags used by ptrace
orig_r8_IS_EXCPN and orig_r8_IS_BRKPT were same values due to a
copy/paste error. Although it looks bad and is wrong, it really doesn't
affect gdb working.

orig_r8_IS_BRKPT is the one relevant to debugging (breakpoints), since
it is used to provide EFA vs. ERET to a ptrace "stop_pc" request.

So when gdb has inserted a breakpoint, orig_r8_IS_BRKPT is already set,
and anything else (i.e. orig_r8_IS_EXCPN) becoming same as it, really
doesn't hurt gdb. The corollary case, could be nasty but nobody uses the
ptrace "stop_pc" request in that case

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-20 18:45:45 +05:30
Pierrick Hascoet 2105fd550c arc: fix dma_address assignment during dma_map_sg()
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-19 15:34:53 +05:30
Masanari Iida cf2fbdd26f treewide: Fix typos in printk and comment
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-03-18 14:57:53 +01:00
Paul Bolle b237ba8f47 arc: fix incorrect ifdef comment
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-03-18 11:01:16 +01:00
Vineet Gupta a37b2dc52b ARC: Remove SET_PERSONALITY (tracks cross-arch change)
Tracks commit e72837e3e7 "default SET_PERSONALITY() in linux/elf.h"

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-18 14:37:05 +05:30
Vineet Gupta 180d406e49 ARC: ABIv3: fork/vfork wrappers not needed in "no-legacy-syscall" ABI
When switching to clone() only ABI - I missed out pruning the low level
asm syscall wrappers

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-11 19:01:10 +05:30
Vineet Gupta 8ff14bbc6a ARC: ABIv3: Print the correct ABI ver
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-11 19:01:09 +05:30
Vineet Gupta 1540c85b17 ARC: make allyesconfig build breakages
CC      drivers/mmc/host/mmc_spi.o
drivers/mmc/host/mmc_spi.c:118: error: redefinition of 'struct scratch'
make[3]: *** [drivers/mmc/host/mmc_spi.o] Error 1
make[2]: *** [drivers/mmc/host] Error 2
make[1]: *** [drivers/mmc] Error 2
make: *** [drivers] Error 2

  CC      arch/arc/kernel/kgdb.o
In file included from include/linux/kgdb.h:20,
                 from arch/arc/kernel/kgdb.c:11:
/home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34:
warning: 'struct pt_regs' declared inside parameter list
/home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34:
warning: its scope is only this definition or declaration, which is
probably not what you want
arch/arc/kernel/kgdb.c:172: error: conflicting types for 'kgdb_trap'

  CC      arch/arc/kernel/kgdb.o
arch/arc/kernel/kgdb.c: In function 'pt_regs_to_gdb_regs':
arch/arc/kernel/kgdb.c:62: error: dereferencing pointer to incomplete
type

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-11 19:01:09 +05:30
Vineet Gupta 8ccfe6675f ARC: split elf.h into uapi and export it for userspace
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-27 20:00:26 +05:30
Vineet Gupta 17139053eb ARC: Fixup the current ABI version
The upstream kernel ABI (v3) is different from current out-of-tree (v2):
* no-legacy-syscalls
* user_regs_struct layout has changed

So we rev up the ABI version

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-27 20:00:25 +05:30
Vineet Gupta 5dc99e50d2 ARC: gdbserver using regset interface possibly broken
ptrace regset interface relies on ELF_NGREG for ceiling the size of user
request. So any larger request (even if legit)  would be clipped.

The existing def of ELF_NGREG didn't use user_regs_struct and was
technically one placeholder short (stop_pc) - although the current code
would still work because pt_regs includes a bunch of extra fields,
making
      ELF_NGREG >= sizeof(struct user_regs_struct)/sizeof(long)

But we need to remove this ambiguity, specially since pt_regs should NOT
be directly associated with with anything userspace-ish.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-27 19:59:55 +05:30
Vineet Gupta 7e0d306c37 ARC: Kconfig cleanup tracking cross-arch Kconfig pruning in merge window
Since ARC port was not yet upstream, we missed a bunch of cross-arch
Kconfig removals:

* GENERIC_SIGALTSTACK: d64008a8f3 "burying unused conditionals"
* HAVE_IRQ_WORK: 6147a9d807 "irq_work: Remove CONFIG_HAVE_IRQ_WORK"
* ARCH_NO_VIRT_TO_BUS: e0cf2ef484 "arch Kconfig: centralise
                                   CONFIG_ARCH_NO_VIRT_TO_BUS"

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-26 14:25:22 +05:30
Vineet Gupta eab6a08c08 ARC: make a copy of flat DT
The flat DT (currently embedded in vmlinux) is in .init section.
The unflattened/binary tree doesn't copy strings through and references
them from orig flat DT - which could cause catestrohpy if of_* APIs are
called post init, say from a driver which is a loadable module.

Reported-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-26 14:25:18 +05:30
Vineet Gupta fc32781bfd ARC: [plat-arcfpga] DT arc-uart bindings change: "baud" => "current-speed"
Per Grant's review comment - driver changes via tty tree

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:22 +05:30
Vineet Gupta 70b319f2be ARC: Ensure CONFIG_VIRT_TO_BUS is not enabled
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reported-by: James Hogan <james.hogan@imgtec.com>
2013-02-15 23:16:21 +05:30
Vineet Gupta 3eb3e7dd53 ARC: Fix pt_orig_r8 access
Syscall restarting fixes made pt_regs->orig_r8 a short word, which was
not reflected in the assembler code - thus could potentially break gdb
debugging.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:21 +05:30
Vineet Gupta 7f85e5ec0d ARC: [3.9] Fallout of hlist iterator update
Commit 0bbacca "hlist: drop the node parameter from iterators" changed
the iterator across the board - but ARC port being out-of-tree missed
it.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:20 +05:30
Vineet Gupta 1e26662993 ARC: 64bit RTSC timestamp hardware issue
The 64bit RTSC is not reliable, causing spurious "jumps" in higher word,
making Linux timekeeping go bonkers. So as of now just use the lower
32bit timestamp.

A cleaner approach would have been removing RTSC support altogether as the
32bit RTSC is equivalent to old TIMER1 based solution, but some customers
can use the 32bit RTSC in SMP syn fashion (vs. TIMER1 which being incore
can't be done easily).

A fallout of this is sched_clock()'s hardware assisted version needs to
go away since it can't use 32bit wrapping counter - instead we use the
generic "weak" jiffies based version.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:20 +05:30
Vineet Gupta d626f547dd ARC: Don't fiddle with non-existent caches
!CONFIG_ARC_HAS_(I|D)CACHE makes Linux disable caches (assuming they
exist in hardware) - mostly for debugging issues with new peripherals.
However, independent of CONFIG_ARC_HAS_(I|D)CACHE, Linux also needs to
handle, non-existant caches, using the information in Cache BCRs (Build
Configuration Reg)

Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:19 +05:30
Vineet Gupta 0208c96a9d ARC: Provide a default serial.h for uart drivers needing BASE_BAUD
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:18 +05:30
Vineet Gupta 95461a64e9 ARC: [plat-arcfpga] defconfig for fully loaded ARC Linux
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:17 +05:30
Vineet Gupta b830cde5a4 ARC: [Review] Multi-platform image #8: platform registers SMP callbacks
Platforms export their SMP callbacks by populating arc_smp_ops.
The population itself needs to be done pretty early, from init_early
callback.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:17 +05:30
Vineet Gupta 10b1271875 ARC: [Review] Multi-platform image #7: SMP common code to use callbacks
This again is for switch from singleton platform SMP API to
multi-platform paradigm

Platform code is not yet setup to populate the callbacks, that happens
in next commit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:16 +05:30