Add Kconfig symbol, asm/mtd-xip.h header and define related macros:
xip_cpu_idle, xip_irqpending, xip_currtime and xip_elapsed_since.
Append .xiptext to the vectors when separate vectors are configured
because otherwise they are appended to the data and data may not even be
executable in XIP configuration.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org
Whether xtensa cores start from primary or secondary reset vector is
configurable and may be chosen by board designer or controlled at
runtime. When secondary reset vector is unused its location in memory
may not be writable.
Make secondary reset vector support conditional and don't build and load
secondary reset vector code when it is disabled.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
There's no need in window overflow/underflow/alloca exception handlers
or window spill code when neither kernel nor userspace support windowed
registers. Don't build or link it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Allow vectors to be either merged into the kernel .text or put at a
fixed virtual address independently of XIP option. Drop option that
puts vectors at a fixed offset from the kernel text. Add choice to
Kconfig.
Vectors at fixed virtual address may be useful for XIP-aware MTD support
and for noMMU configurations with available IRAM. Configurations without
VECBASE register must put their vectors at specific locations regardless
of the selected option. All other configurations should happily use
merged vectors.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
There's no real dependency between SMP and XIP, allow them to be
selected together. Always define 2- and 4-argument SECTION_VECTOR
macros, always use 4-argument macro for the secondary reset vector and
always define relocation entry for it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
On XIP kernels it makes sense to have exception vectors and fast
exception handlers together (in a fast memory). In addition, with MTD
XIP support both vectors and fast exception handlers must be outside of
the FLASH.
Add section .exception.text and move fast exception handlers to it.
Put it together with vectors when vectors are outside of the .text.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- add support for execute in place (XIP) kernels
- improvements in inline assembly: use named arguments and "m"
constraints where possible
- improve stack dumping
- clean up system_call code and syscall tracing
- various small fixes and cleanups
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Merge tag 'xtensa-20191201' of git://github.com/jcmvbkbc/linux-xtensa
Pull Xtensa updates from Max Filippov:
- add support for execute in place (XIP) kernels
- improvements in inline assembly: use named arguments and "m"
constraints where possible
- improve stack dumping
- clean up system_call code and syscall tracing
- various small fixes and cleanups
* tag 'xtensa-20191201' of git://github.com/jcmvbkbc/linux-xtensa: (30 commits)
xtensa: clean up system_call/xtensa_rt_sigreturn interaction
xtensa: fix system_call interaction with ptrace
xtensa: rearrange syscall tracing
xtensa: fix syscall_set_return_value
xtensa: drop unneeded headers from coprocessor.S
xtensa: entry: Remove unneeded need_resched() loop
xtensa: use MEMBLOCK_ALLOC_ANYWHERE for KASAN shadow map
xtensa: fix TLB sanity checker
xtensa: get rid of __ARCH_USE_5LEVEL_HACK
xtensa: mm: fix PMD folding implementation
xtensa: make stack dump size configurable
xtensa: improve stack dumping
xtensa: use "m" constraint instead of "r" in futex.h assembly
xtensa: use "m" constraint instead of "a" in cmpxchg.h assembly
xtensa: use named assembly arguments in cmpxchg.h
xtensa: use "m" constraint instead of "a" in atomic.h assembly
xtensa: use named assembly arguments in atomic.h
xtensa: use "m" constraint instead of "a" in bitops.h assembly
xtensa: use named assembly arguments in bitops.h
xtensa: use macros to generate *_bit and test_and_*_bit functions
...
XIP (eXecute In Place) kernel image is the image that can be run
directly from ROM, using RAM only for writable data.
XIP xtensa kernel differs from regular xtensa kernel in the following
ways:
- it has exception/IRQ vectors merged into text section. No vectors
relocation takes place at kernel startup.
- .data/.bss location must be specified in the kernel configuration,
its content is copied there in the _startup function.
- .init.text is merged with the rest of text and is executed from ROM.
- when MMU is used the virtual address where the kernel will be mapped
must be specified in the kernel configuration. It may be in the KSEG
or in the KIO, __pa macro is adjusted to be able to handle both.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Introduce the header arch/xtensa/include/asm/core.h that provides
definitions for XCHAL macros missing in older xtensa releases. Use this
header instead of variant/core.h
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- use ZONE_NORMAL instead of ZONE_DMA;
- fix Image.elf build error caused by assignment of incorrect address
to the .note.Linux section;
- clean up debug and property sections in the vmlinux.lds.S.
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Merge tag 'xtensa-20181101' of git://github.com/jcmvbkbc/linux-xtensa
Pull Xtensa fixes and cleanups from Max Filippov:
- use ZONE_NORMAL instead of ZONE_DMA
- fix Image.elf build error caused by assignment of incorrect address
to the .note.Linux section
- clean up debug and property sections in the vmlinux.lds.S
* tag 'xtensa-20181101' of git://github.com/jcmvbkbc/linux-xtensa:
xtensa: clean up xtensa-specific property sections
xtensa: use DWARF_DEBUG in the vmlinux.lds.S
xtensa: add NOTES section to the linker script
xtensa: remove ZONE_DMA
xtensa-specific property sections may be section-specific. They should
be collected in the order of appearance. .gnu.linkonce.prop.* input
sections should be collected into the .xt.prop output section.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Xtensa doesn't have anything custom in its debug sections list. Use
macro DWARF_DEBUG instead of opencoding it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This section collects all source .note.* sections together in the
vmlinux image. Without it .note.Linux section may be placed at address
0, while the rest of the kernel is at its normal address, resulting in a
huge vmlinux.bin image that may not be linked into the xtensa Image.elf.
Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Since the struct lsm_info table is not an initcall, we can just move it
into INIT_DATA like all the other tables.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
platform/hardware.h no longer supply any information for processor.h,
vectors.h, setup.c or vmlinux.lds.S, don't include it.
This header is now empty in the platforms/iss, so remove it altogether.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
vmlinux.lds.S doesn't do anything special with literals, so instead of
keeping them separate put them into the corresponding text sections.
Drop explicit .literal sections from the vmlinux.lds.S, use standard
section macros. Mark literal pool locations in the assembly sources.
Unfortunately assembler doesn't put literals into .init sections and
external libgcc may still have .literal sections, so sed transformation
to the linker script is still needed.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Double exception vector only needs 20 bytes of space for 5 literals, not
48. Reduce the reservation for double exception vector literals
accordingly. This fixes build for configurations with small user
exception vector size.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Currently code for exception/IRQ vectors is stored in kernel image as
initialization data and is copied to its working addresses during
startup. It doesn't always make sense. In many cases vectors location
can be automatically decided at kernel link time and code can be placed
right there. This is especially useful for XIP kernel.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
When doing an nmi backtrace of many cores, most of which are idle, the
output is a little overwhelming and very uninformative. Suppress
messages for cpus that are idling when they are interrupted and just
emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".
We do this by grouping all the cpuidle code together into a new
.cpuidle.text section, and then checking the address of the interrupted
PC to see if it lies within that section.
This commit suitably tags x86 and tile idle routines, and only adds in
the minimal framework for other architectures.
Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Tested-by: Petr Mladek <pmladek@suse.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make kernel load address explicit, independent of the selected MMU
configuration and configurable from Kconfig. Do not restrict it to the
first 512MB of the physical address space.
Cleanup kernel memory layout macros:
- rename VECBASE_RESET_VADDR to VECBASE_VADDR, XC_VADDR to VECTOR_VADDR;
- drop VIRTUAL_MEMORY_ADDRESS and LOAD_MEMORY_ADDRESS;
- introduce PHYS_OFFSET and use it in __va and __pa definitions;
- synchronize MMU/noMMU vectors, drop unused NMI vector;
- replace hardcoded vectors offset of 0x3000 with Kconfig symbol.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
There are no .bootstrap or .ResetVector.text sections linked to the
vmlinux image, drop these sections from vmlinux.ld.S. Drop
RESET_VECTOR_VADDR definition only used for .ResetVector.text.
Drop remapped copies of primary and secondary reset vectors, as modern
gdb don't have problems stepping through instructions at arbitrary
locations. Drop corresponding sections from the corresponding linker
scripts.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
There are multiple factors adding to the issue in different
configurations:
- commit 17290231df ("xtensa: add fixup for double exception raised
in window overflow") added function window_overflow_restore_a0_fixup to
double exception vector overlapping reset vector location of secondary
processor cores.
- on MMUv2 cores RESET_VECTOR1_VADDR may point to uncached kernel memory
making code overlapping depend on cache type and size, so that without
cache or with WT cache reset vector code overwrites double exception
code, making issue even harder to detect.
- on MMUv3 cores RESET_VECTOR1_VADDR may point to unmapped area, as
MMUv3 cores change virtual address map to match MMUv2 layout, but
reset vector virtual address is given for the original MMUv3 mapping.
- physical memory region of the secondary reset vector is not reserved
in the physical memory map, and thus may be allocated and overwritten
at arbitrary moment.
Fix it as follows:
- move window_overflow_restore_a0_fixup code to .text section.
- define RESET_VECTOR1_VADDR so that it points to reset vector in the
cacheable MMUv2 map for cores with MMU.
- reserve reset vector region in the physical memory map. Drop separate
literal section and build mxhead.S with text section literals.
Cc: <stable@vger.kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Double exceptions that happen during register window overflow/underflow
are handled in the topmost stack frame, as if it was the only exception
that occured. However unaligned access exception handler is special
because it needs to analyze instruction that caused the exception, but
the userspace instruction that triggered window exception is completely
irrelevant. Unaligned data access is rather normal in the generic
userspace code, but stack pointer manipulation must always be done by
architecture-aware code and thus unaligned stack means a serious problem
anyway.
Use the default unaligned access handler that raises SIGBUS in case
of unaligned access in window overflow/underflow handler.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
There are two FIXMEs in the double exception handler 'for the extremely
unlikely case'. This case gets hit by gcc during kernel build once in
a few hours, resulting in an unrecoverable exception condition.
Provide missing fixup routine to handle this case. Double exception
literals now need 8 more bytes, add them to the linker script.
Also replace bbsi instructions with bbsi.l as we're branching depending
on 8th and 7th LSB-based bits of exception address.
This may be tested by adding the explicit DTLB invalidation to window
overflow handlers, like the following:
--- a/arch/xtensa/kernel/vectors.S
+++ b/arch/xtensa/kernel/vectors.S
@@ -592,6 +592,14 @@ ENDPROC(_WindowUnderflow4)
ENTRY_ALIGN64(_WindowOverflow8)
s32e a0, a9, -16
+ bbsi.l a9, 31, 1f
+ rsr a0, ccount
+ bbsi.l a0, 4, 1f
+ pdtlb a0, a9
+ idtlb a0
+ movi a0, 9
+ idtlb a0
+1:
l32e a0, a1, -12
s32e a2, a9, -8
s32e a1, a9, -12
Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This is largely based on SMP code from the xtensa-2.6.29-smp tree by
Piet Delaney, Marc Gauthier, Joe Taylor, Christian Zankel (and possibly
other Tensilica folks).
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
Add support for dispatching medium-priority interrupts, that is,
interrupts of priority levels 2 to EXCM_LEVEL. IRQ handling may be
preempted by higher priority IRQ.
Signed-off-by: Marc Gauthier <marc@tensilica.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
Remove Kconfig entries, boot subdirectory, dependencies from other
boot-* Makefiles, and sections from ld scripts.
Remove stale redboot code that used to pass initrd addresses in a3 and
a4 to _start.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
commit a2d063ac21 ("extable, core_kernel_data(): Make sure all archs
define _sdata") missed xtensa. Xtensa does have a start of data marker,
but calls it _fdata, causing
kernel/built-in.o:(.text+0x964): undefined reference to `_sdata'
_stext was already defined, but it was duplicated by _fdata.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Percpu allocator honors alignment request upto PAGE_SIZE and both the
percpu addresses in the percpu address space and the translated kernel
addresses should be aligned accordingly. The calculation of the
former depends on the alignment of percpu output section in the kernel
image.
The linker script macros PERCPU_VADDR() and PERCPU() are used to
define this output section and the latter takes @align parameter.
Several architectures are using @align smaller than PAGE_SIZE breaking
percpu memory alignment.
This patch removes @align parameter from PERCPU(), renames it to
PERCPU_SECTION() and makes it always align to PAGE_SIZE. While at it,
add PCPU_SETUP_BUG_ON() checks such that alignment problems are
reliably detected and remove percpu alignment comment recently added
in workqueue.c as the condition would trigger BUG way before reaching
there.
For um, this patch raises the alignment of percpu area. As the area
is in .init, there shouldn't be any noticeable difference.
This problem was discovered by David Howells while debugging boot
failure on mn10300.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
Currently percpu readmostly subsection may share cachelines with other
percpu subsections which may result in unnecessary cacheline bounce
and performance degradation.
This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
linker macros, makes each arch linker scripts specify its cacheline
size and use it to align percpu subsections.
This is based on Shaohua's x86 only patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shaohua.li@intel.com>
Discarded sections in different archs share some commonality but have
considerable differences. This led to linker script for each arch
implementing its own /DISCARD/ definition, which makes maintaining
tedious and adding new entries error-prone.
This patch makes all linker scripts to move discard definitions to the
end of the linker script and use the common DISCARDS macro. As ld
uses the first matching section definition, archs can include default
discarded sections by including them earlier in the linker script.
ia64 is notable because it first throws away some ia64 specific
subsections and then include the rest of the sections into the final
image, so those sections must be discarded before the inclusion.
defconfig compile tested for x86, x86-64, powerpc, powerpc64, ia64,
alpha, sparc, sparc64 and s390. Michal Simek tested microblaze.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Tested-by: Michal Simek <monstr@monstr.eu>
Cc: linux-arch@vger.kernel.org
Cc: Michal Simek <monstr@monstr.eu>
Cc: microblaze-uclinux@itee.uq.edu.au
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Tony Luck <tony.luck@intel.com>
x86 throws away .discard section but no other archs do. Also,
.discard is not thrown away while linking modules. Make every arch
and module linking throw it away. This will be used to define dummy
variables for percpu declarations and definitions.
This patch is based on Ivan Kokshaysky's alpha percpu patch.
[ Impact: always throw away everything in .discard ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Fix resembles implementation from Marc Gauthier and Piet Denaly:
In the Xtensa architecture, assembly generates literals which must always
precede the code (the L32R instruction that loads them only uses negative
PC-relative offsets). For any *.text section, literals are placed in a
corresponding *.literal section. The linker script (vmlinux.lds) must
place these in the correct order. It must also combine them, when the
*.text section can be larger than L32R's 256 kB range.
For example, this doesn't work: *(.literal) *(.text) because L32R
instructions at the end of .text can't reach the literals.
The linker can solve this if they are combined in parentheses, like this:
*(.literal .text)
because it is now allowed mix literals in .text to bring them in range.
None of this is done by standard vmlinux.lds.h macros such as TEXT_TEXT
and INIT_TEXT. To avoid replicating the logic of that header file, we
instead post-process the generated linker script to convert *(xxx.text)
to *(xxx.literal xxx.text) for the following text sections:
.text .ref.text .*init.text .*exit.text .text.*
using a sed script. To do this we must override the default rule for
vmlinux.lds (see scripts/Makefile.build and the top-level Makefile)
to insert this extra step.
Signed-off-by: Marc Gauthier <marc@tensilica.com>
Signed-off-by: Pete Delaney <piet@tensilica.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
The linker script should not assume a fix offset in memory for the
kernel, this is platform-specific, so let the platform set it.
Signed-off-by: Johannes Weiner <jw@emlix.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
Move all header files for xtensa to arch/xtensa/include and platform and
variant header files to the appropriate arch/xtensa/platforms/ and
arch/xtensa/variants/ directories.
Moving the files gets also rid of all uses of symlinks in the Makefile.
This has been completed already for the majority of the architectures
and xtensa is one out of six missing.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Chris Zankel <chris@zankel.net>
Xtensa requires separate .literal section for each .text section.
Adding addition init sections for cpuinit, meminit, and devinit,
broke the Xtensa linker script, so, add these literal sections
manually for now.
Signed-off-by: Chris Zankel <chris@zankel.net>
This patch consolidate all definitions of .init.text, .init.data
and .exit.text, .exit.data section definitions in
the generic vmlinux.lds.h.
This is a preparational patch - alone it does not buy
us much good.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (33 commits)
xtensa: use DATA_DATA in xtensa
powerpc: add missing DATA_DATA to powerpc
cris: use DATA_DATA in cris
kallsyms: remove usage of memmem and _GNU_SOURCE from scripts/kallsyms.c
kbuild: use -fno-optimize-sibling-calls unconditionally
kconfig: reset generated values only if Kconfig and .config agree.
kbuild: fix the warning when running make tags
kconfig: strip 'CONFIG_' automatically in kernel configuration search
kbuild: use POSIX BRE in headers install target
Whitelist references from __dbe_table to .init
modpost white list pattern adjustment
kbuild: do section mismatch check on full vmlinux
kbuild: whitelist references from variables named _timer to .init.text
kbuild: remove hardcoded _logo names from modpost
kbuild: remove hardcoded apic_es7000 from modpost
kbuild: warn about references from .init.text to .exit.text
kbuild: consolidate section checks
kbuild: refactor code in modpost to improve maintainability
kbuild: ignore section mismatch warnings originating from .note section
kbuild: .paravirtprobe section is obsolete, so modpost doesn't need to handle it
...
per cpu data section contains two types of data. One set which is
exclusively accessed by the local cpu and the other set which is per cpu,
but also shared by remote cpus. In the current kernel, these two sets are
not clearely separated out. This can potentially cause the same data
cacheline shared between the two sets of data, which will result in
unnecessary bouncing of the cacheline between cpus.
One way to fix the problem is to cacheline align the remotely accessed per
cpu data, both at the beginning and at the end. Because of the padding at
both ends, this will likely cause some memory wastage and also the
interface to achieve this is not clean.
This patch:
Moves the remotely accessed per cpu data (which is currently marked
as ____cacheline_aligned_in_smp) into a different section, where all the data
elements are cacheline aligned. And as such, this differentiates the local
only data and remotely accessed data cleanly.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Sam Ravnborg (sam@ravnborg.org) wrote:
> From your patch it looks like I originally missed out
> powerpc + xtensa when introducing DATA_DATA - would be nice if
> you could fix that.
>
> Sam
Use DATA_DATA in xtensa
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
