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176151 commits

Author SHA1 Message Date
David Howells
491424c0f4 PCI: Global variable decls must match the defs in section attributes
Global variable declarations must match the definitions in section attributes
as the compiler is at liberty to vary the method it uses to access a variable,
depending on the section it is in.

When building the FRV arch, I now see:

  drivers/built-in.o: In function `pci_apply_final_quirks':
  drivers/pci/quirks.c:2606: relocation truncated to fit: R_FRV_GPREL12 against symbol `pci_dfl_cache_line_size' defined in .devinit.data section in drivers/built-in.o
  drivers/pci/quirks.c:2623: relocation truncated to fit: R_FRV_GPREL12 against symbol `pci_dfl_cache_line_size' defined in .devinit.data section in drivers/built-in.o
  drivers/pci/quirks.c:2630: relocation truncated to fit: R_FRV_GPREL12 against symbol `pci_dfl_cache_line_size' defined in .devinit.data section in drivers/built-in.o

because the declaration of pci_dfl_cache_line_size in linux/pci.h does not
match the definition in drivers/pci/pci.c.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-14 10:11:34 -08:00
David Howells
5185fb0699 FRV: Fix no-hardware-breakpoint case
If there is no hardware breakpoint support, modify_user_hw_breakpoint()
tries to return a NULL pointer through as an 'int' return value:

  In file included from kernel/exit.c:53:
  include/linux/hw_breakpoint.h: In function 'modify_user_hw_breakpoint':
  include/linux/hw_breakpoint.h:96: warning: return makes integer from pointer without a cast

Return 0 instead.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-14 10:10:55 -08:00
Linus Torvalds
464480f72e Merge branch 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze
* 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze: (46 commits)
  microblaze: Remove rt_sigsuspend wrapper
  microblaze: nommu: Don't clobber R11 on syscalls
  microblaze: Remove show_tmem function
  microblaze: Support for WB cache
  microblaze: Add PVR for Microblaze v7.30.a
  microblaze: Remove ancient and fake microblaze version from cpu_ver table
  microblaze: Remove panic_timeout init value
  microblaze: Do not count system calls in default
  microblaze: Enable DTC compilation
  microblaze: Core oprofile configs and hooks
  microblaze: Fix level interrupt ACKing
  microblaze: Enable futimesat syscall
  microblaze: Checking DTS against PVR for write-back cache
  microblaze: Remove duplicity from pgalloc.h
  microblaze: Futex support
  microblaze: Adding dev_arch_data functions
  microblaze: Fix the heartbeat gpio to be more robust
  microblaze: Simple __copy_tofrom_user for noMMU
  microblaze: Export memory_start for modules
  microblaze: Use lowest-common-denominator default CPU settings
  ...
2009-12-14 10:04:04 -08:00
Linus Torvalds
37222e1c9e Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (27 commits)
  md: add 'recovery_start' per-device sysfs attribute
  md: rcu_read_lock() walk of mddev->disks in md_do_sync()
  md: integrate spares into array at earliest opportunity.
  md: move compat_ioctl handling into md.c
  md: revise Kconfig help for MD_MULTIPATH
  md: add MODULE_DESCRIPTION for all md related modules.
  raid: improve MD/raid10 handling of correctable read errors.
  md/raid10: print more useful messages on device failure.
  md/bitmap: update dirty flag when bitmap bits are explicitly set.
  md: Support write-intent bitmaps with externally managed metadata.
  md/bitmap: move setting of daemon_lastrun out of bitmap_read_sb
  md: support updating bitmap parameters via sysfs.
  md: factor out parsing of fixed-point numbers
  md: support bitmap offset appropriate for external-metadata arrays.
  md: remove needless setting of thread->timeout in raid10_quiesce
  md: change daemon_sleep to be in 'jiffies' rather than 'seconds'.
  md: move offset, daemon_sleep and chunksize out of bitmap structure
  md: collect bitmap-specific fields into one structure.
  md/raid1: add takeover support for raid5->raid1
  md: add honouring of suspend_{lo,hi} to raid1.
  ...
2009-12-14 10:03:36 -08:00
Linus Torvalds
76b8f82cde Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6: (58 commits)
  mfd: Add twl6030 regulator subdevices
  regulator: Add support for twl6030 regulators
  rtc: Add twl6030 RTC support
  mfd: Add support for twl6030 irq framework
  mfd: Rename twl4030_ routines in twl-regulator.c
  mfd: Rename twl4030_ routines in rtc-twl.c
  mfd: Rename all twl4030_i2c*
  mfd: Rename twl4030* driver files to enable re-use
  mfd: Clarify twl4030 return value for read and write
  mfd: Add all twl4030 regulators to the twl4030 mfd driver
  mfd: Don't set mc13783 ADREFMODE for touch conversions
  mfd: Remove ezx-pcap defines for custom led gpio encoding
  mfd: Near complete mc13783 rewrite
  mfd: Remove build time warning for WM835x register default tables
  mfd: Force I2C to be built in when building WM831x
  mfd: Don't allow wm831x to be built as a module
  mfd: Fix incorrect error check for wm8350-core
  mfd: Fix twl4030 warning
  gpiolib: Implement gpio_to_irq() for wm831x
  mfd: Remove default selection of AB4500
  ...
2009-12-14 10:02:35 -08:00
Linus Torvalds
af853e631d Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: fix lh7a40x build
  ARM: fix sa1100 build
  ARM: fix clps711x, footbridge, integrator, ixp2000, ixp2300 and s3c build bug
  ARM: VFP: fix vfp thread init bug and document vfp notifier entry conditions
  ARM: pxa: fix now incorrect reference of skt->irq by using skt->socket.pci_irq
  [ARM] pxa/zeus: default configuration for Arcom Zeus SBC.
  [ARM] pxa/zeus: make Viper pcmcia support more generic to support Zeus
  [ARM] pxa/zeus: basic support for Arcom Zeus SBC
  [ARM] pxa/em-x270: fix usb hub power up/reset sequence
  PCMCIA: fix pxa2xx_lubbock modular build error
  ARM: RealView: Fix typo in the RealView/PBX Kconfig entry
  ARM: Do not allow the probing of the local timer
  ARM: Add an earlyprintk debug console
2009-12-14 10:01:15 -08:00
Linus Torvalds
3f86ce72cf Merge git://git.linux-nfs.org/projects/trondmy/nfs-2.6
* git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (75 commits)
  NFS: Fix nfs_migrate_page()
  rpc: remove unneeded function parameter in gss_add_msg()
  nfs41: Invoke RECLAIM_COMPLETE on all new client ids
  SUNRPC: IS_ERR/PTR_ERR confusion
  NFSv41: Fix a potential state leakage when restarting nfs4_close_prepare
  nfs41: Handle NFSv4.1 session errors in the delegation recall code
  nfs41: Retry delegation return if it failed with session error
  nfs41: Handle session errors during delegation return
  nfs41: Mark stateids in need of reclaim if state manager gets stale clientid
  NFS: Fix up the declaration of nfs4_restart_rpc when NFSv4 not configured
  nfs41: Don't clear DRAINING flag on NFS4ERR_STALE_CLIENTID
  nfs41: nfs41_setup_state_renewal
  NFSv41: More cleanups
  NFSv41: Fix up some bugs in the NFS4CLNT_SESSION_DRAINING code
  NFSv41: Clean up slot table management
  NFSv41: Fix nfs4_proc_create_session
  nfs41: Invoke RECLAIM_COMPLETE
  nfs41: RECLAIM_COMPLETE functionality
  nfs41: RECLAIM_COMPLETE XDR functionality
  Cleanup some NFSv4 XDR decode comments
  ...
2009-12-14 10:00:24 -08:00
Linus Torvalds
d0316554d3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
  m68k: rename global variable vmalloc_end to m68k_vmalloc_end
  percpu: add missing per_cpu_ptr_to_phys() definition for UP
  percpu: Fix kdump failure if booted with percpu_alloc=page
  percpu: make misc percpu symbols unique
  percpu: make percpu symbols in ia64 unique
  percpu: make percpu symbols in powerpc unique
  percpu: make percpu symbols in x86 unique
  percpu: make percpu symbols in xen unique
  percpu: make percpu symbols in cpufreq unique
  percpu: make percpu symbols in oprofile unique
  percpu: make percpu symbols in tracer unique
  percpu: make percpu symbols under kernel/ and mm/ unique
  percpu: remove some sparse warnings
  percpu: make alloc_percpu() handle array types
  vmalloc: fix use of non-existent percpu variable in put_cpu_var()
  this_cpu: Use this_cpu_xx in trace_functions_graph.c
  this_cpu: Use this_cpu_xx for ftrace
  this_cpu: Use this_cpu_xx in nmi handling
  this_cpu: Use this_cpu operations in RCU
  this_cpu: Use this_cpu ops for VM statistics
  ...

Fix up trivial (famous last words) global per-cpu naming conflicts in
	arch/x86/kvm/svm.c
	mm/slab.c
2009-12-14 09:58:24 -08:00
William Allen Simpson
fb0bbb92d4 Documentation: rw_lock lessons learned
In recent months, two different network projects erroneously
strayed down the rw_lock path.  Update the Documentation
based upon comments by Eric Dumazet and Paul E. McKenney in
those threads.

Further updates await somebody else with more expertise.

Changes:
  - Merged with extensive content by Stephen Hemminger.
  - Fix one of the comments by Linus Torvalds.

Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-14 09:46:56 -08:00
Michal Simek
571202f50f microblaze: Remove rt_sigsuspend wrapper
Generic rt_sigsuspend syscalls doesn't need any asm wrapper.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:12 +01:00
steve@digidescorp.com
825c9a359e microblaze: nommu: Don't clobber R11 on syscalls
The noMMU syscall trap has a bug that causes R11 to be zero on return to
userland. Remove the extra "save" of R11 responsible for the bug.

Remove reloading of mode indicator because r11 already contains it.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:11 +01:00
Michal Simek
233eb92115 microblaze: Remove show_tmem function
show_tmem function do nothing that's why I removed it.
There is also cleaning of commented ancient code.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:11 +01:00
Michal Simek
2ee2ff875a microblaze: Support for WB cache
Microblaze version 7.20.d is the first MB version which can be run
on MMU linux. Please do not used previous version because they contain
HW bug.
Based on WB support was necessary to redesign whole cache design.
Microblaze versions from 7.20.a don't need to disable IRQ and cache
before working with them that's why there are special structures for it.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:10 +01:00
Michal Simek
c8983a5c6e microblaze: Add PVR for Microblaze v7.30.a
Microblaze v7.30.a will have 0x10 version string.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:10 +01:00
Michal Simek
81ab0dfd94 microblaze: Remove ancient and fake microblaze version from cpu_ver table
We need to continue with next microblaze PVR version that's why
I have to remove that ancient version. These version strings not match
any versions. From Microblaze v5.00.a is possible to use this style.
I believe that none use ancients versions. If yes they will be just
labeled as unknown version.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:09 +01:00
Michal Simek
5de2344630 microblaze: Remove panic_timeout init value
panic_timeout is in BSS section and it is cleared with BSS section.
This means that value is setup to 0.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:09 +01:00
Michal Simek
11d5136043 microblaze: Do not count system calls in default
There is not necessary to count system calls that's why
I added DEBUG macro

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:08 +01:00
Michal Simek
3c5e56724d microblaze: Enable DTC compilation
For simpleImage format we need to compile DTC. There is still possibility
to compile only Linux kernel without DTB compiled-in.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:08 +01:00
John Williams
3540ce8238 microblaze: Core oprofile configs and hooks
Microblaze uses timer interrupt mode. Microblaze don't have
any performance counter that's why we use just simple implementation.

Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:07 +01:00
steve@digidescorp.com
33d9ff5985 microblaze: Fix level interrupt ACKing
Level interrupts need to be ack'd in the unmask handler, as in powerpc.
Among other issues, this bug causes the system clock to appear to run at
double-speed.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:06 +01:00
Michal Simek
833d0d8da4 microblaze: Enable futimesat syscall
Futimesat was disabled. LTP testing shows that MB has no
problem with this syscall.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:06 +01:00
Michal Simek
f6e1f1b480 microblaze: Checking DTS against PVR for write-back cache
WB cache has special flag in PVR. There is added checking mechanism
for PVR and DTS.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:05 +01:00
Michal Simek
d4f182700b microblaze: Remove duplicity from pgalloc.h
just file cleanup

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:05 +01:00
Michal Simek
fd3db0a675 microblaze: Futex support
Microblaze v7.20 provides new lwx, swx instructions which bring
possibility to implement lock rutines.

There are some tests in open posix thread LTP part but current
toolchain not support it.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:04 +01:00
Michal Simek
d68bf9705a microblaze: Adding dev_arch_data functions
The functions, dev_arch_data_set_node and get_node are missing
and are needed by some device drivers such as I2C.

Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:04 +01:00
John Linn
6d858535be microblaze: Fix the heartbeat gpio to be more robust
The device tree handling for the gpio in the heart beat was not handling
the system when there was no gpio and it wasn't working with a newer version
of the gpio core which does not have the is-bidir property.

Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:03 +01:00
John Williams
95dfbbe470 microblaze: Simple __copy_tofrom_user for noMMU
This is first patch which clear part of uaccess.h.
uaccess.h will be clear later.

Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:03 +01:00
Michal Simek
fd6ed51f4f microblaze: Export memory_start for modules
memory_start symbol is needed by kernel modules.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:02 +01:00
John Williams
4a7b40c9b8 microblaze: Use lowest-common-denominator default CPU settings
This will ensure that kernels built with no custom CPU settings will still boot
OK on hardware that has additional CPU hardware instructions etc.

Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:02 +01:00
Michal Simek
f99ec58b6a microblaze: Update default generic DTS
It is generated with longer compatible list

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:01 +01:00
Michal Simek
27d2a3ee5e microblaze: Enable asm optimization only for HW with barrel-shifter
Asm code uses barrel-shifter instruction that's why we have
to protect cases when HW don't have it.

Reported-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:01 +01:00
John Williams
3e78e4e5ea microblaze: Remove the buggy ALLOW_EDIT_AUTO config option
This was intended to allow manual override of CPU settings copied automatically
to Kconfig.auto, however it's problematic for several reasons, but mostly:

  * If the defconfig doesn't have ALLOW_EDIT_AUTO=y, then it's impossible for
    that defconfig to iverride the values in the kernel source tree.  This leads
    to very strange errors where the kernel is compiled with the wrong CPUFLAGS.

Next patch in the series will back out the default in Kconfig.auto to baseline
settings, so a kernel built with no default values will at least boot on any
hardware, just not make use of additional CPU features.

Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:00 +01:00
Michal Simek
a1f55113ca microblaze: Move cache macro from cache.h to cacheflush.h
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:00 +01:00
Michal Simek
6a8dfe1cac microblaze: support U-BOOT image format
Two version are generated.
linux.bin.ub which is created from linux.bin file
and
simpleImage.<dts>.ub which is created from stripped simpleImage.<dts> file

Load address and entry point is for microblaze first instruction
which is CONFIG_KERNEL_BASE_ADDR variable.

There is possible for simpleImage format parse _start symbol too.

simpleImage.<dts> is still stripped elf file

I cleared simpleImage.<dts>.unstrip file because there are so big.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:59 +01:00
Michal Simek
a01523cdcd microblaze: Ptrace notifying from signal code
After the signal frame is set up on the userspace stack, ptrace() should
be given an opportunity to single-step into the signal handler

FRV, Blackfin, mn10300 and UM. Worth to look at that patches.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:58 +01:00
Michal Simek
e051af576a microblaze: Extend cpuinfo for support write-back caches
There is missing checking agains PVR but this is not important
for now. There are some missing checking too.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:58 +01:00
Michal Simek
44e4e196a9 microblaze: Fix cache_line_lenght
We used cache_line as cache_line_lenght. For this reason
we did cache flushing 4 times longer than was necessary.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:57 +01:00
Michal Simek
6cec713b16 microblaze: Detect new 7.20.d version
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:57 +01:00
Michal Simek
67bf876654 microblaze: Support both levels for reset
Till this patch reset always perform writen to 1.
Now we can use negative logic and perform reset write to 0.

It is opposite level than is currently read from that pin

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:56 +01:00
Michal Simek
7537583040 microblaze: Fix announce message for reset gpio
I had to change message for gpio-reset because I always
not to see it. Prefix RESET is big and visible.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:56 +01:00
Michal Simek
f7816e284b microblaze: Remove saving and restoring before calling signal code
Saving is done in SAVE_STATE macros that's why another save discard
previous saved value.

This change has no effect to normal programs because they ends in any exception
and they are killed. On the other side has effect on debugging.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:55 +01:00
steve@digidescorp.com
5dd48a235c microblaze: Fix pfn_valid() for noMMU
Configuring DEBUG_SLAB causes a noMMU kernel to die during initialization
with an invalid virtual address panic in kfree_debugcheck().
The panic is due to an improper definition of pfn_valid().

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:55 +01:00
Michal Simek
4f911b0daf microblaze: ftrace: Add dynamic function graph tracer
This patch add support for dynamic function graph tracer.

There is one my expactation that I can do flush_icache after
all code modification. On microblaze is this safer than do
flush for every entry. For icache is used name flush but
correct should be invalidation - this will be fix in upcomming
new cache implementaion and WB support.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:54 +01:00
Michal Simek
a0d3e66522 microblaze: ftrace: add function graph support
For more information look at Documentation/trace folder.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:53 +01:00
Michal Simek
7d241ff056 microblaze: ftrace: Add dynamic trace support
With dynamic function tracer, by default, _mcount is defined as an
"empty" function, it returns directly without any more action. When
enabling it in user-space, it will jump to a real tracing
function(ftrace_caller), and do the real job for us.

Differ from the static function tracer, dynamic function tracer provides
two functions ftrace_make_call()/ftrace_make_nop() to enable/disable the
tracing of some indicated kernel functions(set_ftrace_filter).

In the kernel version, there is only one "_mcount" string for every
kernel function, so, we just need to match this one in mcount_regex of
scripts/recordmcount.pl.

For more information please look at code and Documentation/trace folder.

Steven ACK that scripts/recordmcount.pl part.

Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:01 +01:00
Michal Simek
6d9e60ce30 microblaze: ftrace: enable HAVE_FUNCTION_TRACE_MCOUNT_TEST
Implement MCOUNT_TEST in asm code - it is faster than use
generic code

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:40:10 +01:00
Michal Simek
2fd7c761a2 microblaze: ftrace: add static function tracer
If -pg of gcc is enabled with CONFIG_FUNCTION_TRACER=y. a calling to
_mcount will be inserted into each kernel function. so, there is a
possibility to trace the kernel functions in _mcount.

This patch add the specific _mcount support for static function
tracing. by default, ftrace_trace_function is initialized as
ftrace_stub(an empty function), so, the default _mcount will introduce
very little overhead. after enabling ftrace in user-space, it will jump
to a real tracing function and do static function tracing for us.

Commit message from Wu Zhangjin <wuzhangjin@gmail.com>

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:40:09 +01:00
Michal Simek
a3cd613b2e microblaze: Add TRACE_IRQFLAGS_SUPPORT
There are just two major changes
Renamed local_irq functions to raw_local_irq in irq.c.
Added TRACE_IRQFLAGS_SUPPORT to Kconfig.debug.

Look at Documentation/irqflags-tracing.txt

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:40:09 +01:00
Michal Simek
fb5a32dc1a microblaze: preliminary enabling for LATENCYTOP support in Kconfig
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:40:09 +01:00
Michal Simek
bf2d809668 microblaze: Lockdep support
Microblaze needs to do lock_init very soon because MMU init calls lock functions.

Here is the explanation from Peter Zijlstra why we have to enable
__ARCH_WANTS_INTERRUPTS_ON_CTSW.

"So we schedule while holding rq->lock (for obvious reasons), but since
lockdep tracks held locks per tasks, we need to transfer the held state
from the prev to the next task. We do this by explicity calling
spin_release(&rq->lock) in context_switch() right before switch_to(),
and calling spin_acquire(&rq->lock) in
finish_task_switch()->finish_lock_switch().

Now, for some reason lockdep thinks that interrupts got enabled over the
context switch (git grep __ARCH_WANTS_INTERRUPTS_ON_CTSW arch/microblaze
doesn't seem to turn up anything).

Clearly trying to acquire the rq->lock with interrupts enabled is a bad
idea and lockdep warns you about this."

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:40:09 +01:00