Commit Graph

110 Commits

Author SHA1 Message Date
Paul Gortmaker 078a55fc82 MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code
commit 3747069b25e419f6b51395f48127e9812abc3596 upstream.

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

Here, we remove all the MIPS __cpuinit from C code and __CPUINIT
from asm files.  MIPS is interesting in this respect, because there
are also uasm users hiding behind their own renamed versions of the
__cpuinit macros.

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

[ralf@linux-mips.org: Folded in Paul's followup fix.]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5494/
Patchwork: https://patchwork.linux-mips.org/patch/5495/
Patchwork: https://patchwork.linux-mips.org/patch/5509/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-07-14 19:36:51 -04:00
Ralf Baechle b22d1b6a91 Merge branch 'mti-next' of git://git.linux-mips.org/pub/scm/sjhill/linux-sjhill into mips-for-linux-next 2013-05-09 17:57:30 +02:00
Ralf Baechle 5e0e61dd2c Merge branch 'next/kvm' into mips-for-linux-next 2013-05-09 17:56:40 +02:00
Sanjay Lal f2e3656d23 MIPS: Export routines needed by the KVM module.
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:36 +02:00
Steven J. Hill b6d92b4a6b MIPS: Add option to disable software I/O coherency.
Some MIPS controllers have hardware I/O coherency. This patch
detects those and turns off software coherency. A new kernel
command line option also allows the user to manually turn
software coherency on or off.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
2013-05-01 16:32:49 -05:00
Deng-Cheng Zhu adb3789264 MIPS: Fix ISA level which causes secondary cache init bypassing and more
The commit a96102be70 introduced set_isa() where compatible ISA info is
also set aside from the one gets passed in. It means, for example, 1004K
will have MIPS_CPU_ISA_M32R2/M32R1/II/I flags. This leads to things like
the following inappropriate:

if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
    c->isa_level == MIPS_CPU_ISA_M32R2 ||
    c->isa_level == MIPS_CPU_ISA_M64R1 ||
    c->isa_level == MIPS_CPU_ISA_M64R2)

This patch fixes it.

Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-04-05 15:10:45 +02:00
Ralf Baechle 8bfc245f9a Merge branch 'mips-next-3.9' of git://git.linux-mips.org/pub/scm/john/linux-john into mips-for-linux-next 2013-02-21 12:51:33 +01:00
Steven J. Hill f8fa4811db MIPS: Add support for the M14KEc core.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Patchwork: http://patchwork.linux-mips.org/patch/4682/
Signed-off-by: John Crispin <blogic@openwrt.org>
2013-02-17 00:15:23 +01:00
Ralf Baechle 7034228792 MIPS: Whitespace cleanup.
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-02-01 10:00:22 +01:00
Ralf Baechle 241738bd51 Merge branch 'mips-next' of http://dev.phrozen.org/githttp/mips-next into mips-for-linux-next 2012-12-13 19:40:13 +01:00
Ralf Baechle bdf20507da MIPS: PMC-Sierra Yosemite: Remove support.
Nobody seems to be interested anymore and upstream also never had an
ethernet driver.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-12-13 18:15:30 +01:00
Ralf Baechle a16dad7763 MIPS: Fix potencial corruption
Normally r4k_dma_cache_inv should only ever be called with cacheline
aligned addresses.  If however, it isn't there is the theoretical
possibility of data corruption.  There is no correct way of handling this
and anyway, it should only happen if the DMA API is used incorrectly
so drop

There is a different corruption scenario with these CACHE instructions
removed but again there is no way of handling this correctly and it can
be triggered only through incorrect use of the DMA API.

So just get rid of the complexity.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: James Rodriguez <jamesr@juniper.net>
2012-12-13 18:15:27 +01:00
Shane McDonald b5b64f2ba4 MIPS: Move processing of coherency kernel parameters earlier
Commit 97ce2c88f9 (jump-label: initialize
jump-label subsystem much earlier) caused MIPS to break, so this was
resolved with commit 6650df3c38 (MIPS:
Move cache setup to setup_arch().).  Unfortunately, after this commit,
the coherency kernel parameters, cca and coherentio, are no longer
processed before their values are used.

This patch fixes this problem by marking them as early_param, which
results in them being processed before they are needed.

Signed-off-by: Shane McDonald <mcdonald.shane@gmail.com>
Acked-by: David Daney <david.daney@cavium.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/3961
Signed-off-by: John Crispin <blogic@openwrt.org>
2012-11-09 11:37:16 +01:00
Steven J. Hill 006a851b10 MIPS: Add support for the 1074K core.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
2012-09-13 15:21:47 -05:00
Douglas Leung dc34b05fea MIPS: Fix decoding of c0_config1 for MIPSxx caches with 32 ways per set.
This affects certain 4Kc cores.

Signed-off-by: Douglas Leung <douglas@mips.com>
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3855/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-07-19 11:23:43 +02:00
Steven J. Hill 113c62d984 MIPS: Add support for the M14Kc core.
[ralf@linux-mips.org: Fixed whitespace damage.]

Signed-off-by: Steven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3773/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-07-06 23:56:00 +02:00
David Daney 9cd9669bd6 MIPS: Use board_cache_error_setup for r4k cache error handler setup.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3821/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-05-16 23:34:34 +02:00
David Howells b81947c646 Disintegrate asm/system.h for MIPS
Disintegrate asm/system.h for MIPS.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
cc: linux-mips@linux-mips.org
2012-03-28 18:30:02 +01:00
Cong Wang 9c02048fcd mips: remove the second argument of k[un]map_atomic()
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20 21:48:14 +08:00
Jayachandran C a3d4fb2d2a MIPS: Netlogic: XLP CPU support.
Add support for Netlogic's XLP MIPS SoC. This patch adds:
* XLP processor ID in cpu_probe.c and asm/cpu.h
* XLP case to asm/module.h
* CPU_XLP case to mm/tlbex.c
* minor change to r4k cache handling to ignore XLP secondary cache
* XLP cpu overrides to mach-netlogic/cpu-feature-overrides.h

Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2966/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-12-07 22:04:55 +00:00
Ralf Baechle d9cdc901af MIPS: cache: Provide cache flush operations for XFS
Until now flush_kernel_vmap_range() and invalidate_kernel_vmap_range() did
not exist on MIPS resulting in heavy cache corruption on XFS filesystems.

Left for the post-3.0 time: optimization and make this work with highmem,
too.  Since the combination of highmem + cache aliases atm doesn't work
this isn't a regression.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2505/
2011-10-20 15:00:18 +01:00
Kevin Cernekee d0023c4a0a MIPS: Add SYNC after cacheflush
On processors with deep write buffers, it is likely that many cycles
will pass between a CACHE instruction and the time the data actually
gets written out to DRAM.  Add a SYNC instruction to ensure that the
buffers get emptied before the flush functions return.

Actual problem seen in the wild:

1) dma_alloc_coherent() allocates cached memory

2) memset() is called to clear the new pages

3) dma_cache_wback_inv() is called to flush the zero data out to memory

4) dma_alloc_coherent() returns an uncached (kseg1) pointer to the
freshly allocated pages

5) Caller writes data through the kseg1 pointer

6) Buffered writeback data finally gets flushed out to DRAM

7) Part of caller's data is inexplicably zeroed out

This patch adds SYNC between steps 3 and 4, which fixed the problem.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: 
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-07-25 17:26:53 +01:00
Linus Torvalds 57d19e80f4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  b43: fix comment typo reqest -> request
  Haavard Skinnemoen has left Atmel
  cris: typo in mach-fs Makefile
  Kconfig: fix copy/paste-ism for dell-wmi-aio driver
  doc: timers-howto: fix a typo ("unsgined")
  perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c
  md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
  treewide: fix a few typos in comments
  regulator: change debug statement be consistent with the style of the rest
  Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations"
  audit: acquire creds selectively to reduce atomic op overhead
  rtlwifi: don't touch with treewide double semicolon removal
  treewide: cleanup continuations and remove logging message whitespace
  ath9k_hw: don't touch with treewide double semicolon removal
  include/linux/leds-regulator.h: fix syntax in example code
  tty: fix typo in descripton of tty_termios_encode_baud_rate
  xtensa: remove obsolete BKL kernel option from defconfig
  m68k: fix comment typo 'occcured'
  arch:Kconfig.locks Remove unused config option.
  treewide: remove extra semicolons
  ...
2011-05-23 09:12:26 -07:00
Jayachandran C efa0f81c11 MIPS: Netlogic: Cache, TLB support and feature overrides for XLR
CPU_XLR case added to mm/tlbex.c
CPU_XLR case added to mm/c-r4k.c for PINDEX attribute
Feature overrides for XLR cpu.

Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2333/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-05-19 09:55:40 +01:00
Ralf Baechle 71271aab8c MIPS: c-r4k: Fix GCC 4.6.0 build error
CC      arch/mips/mm/c-r4k.o
arch/mips/mm/c-r4k.c: In function 'probe_scache':
arch/mips/mm/c-r4k.c:1078:6: error: variable 'tmp' set but not used [-Werror=unused-but-set-variable]
cc1: all warnings being treated as errors

Older GCC versions didn't warn about the unused variable tmp because it was
getting initialized.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-05-10 18:15:22 +01:00
Justin P. Mattock 79add62773 update David Miller's old email address
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-06 06:19:38 -07:00
Ralf Baechle 48a26e60c6 MIPS: Remove wait argument of r4k_on_each_cpu
All callers were passing in 1 anyway.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-10-29 19:08:25 +01:00
Ralf Baechle c8c5f3fd9f MIPS: More detailed description of r4k_on_each_cpu
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-10-29 19:08:25 +01:00
Ralf Baechle 631330f584 MIPS: Build fix - include <linux/smp.h> into all smp_processor_id() users.
Some of the were relying into smp.h being dragged in by another header
which of course is fragile.  <asm/cpu-info.h> uses smp_processor_id()
only in macros and including smp.h there leads to an include loop, so
don't change cpu-info.h.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-06-24 18:34:39 +01:00
Kevin Cernekee 605b7ef7b7 MIPS: Support 64-byte D-cache line size
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-06-17 11:06:24 +01:00
Ralf Baechle 7fc7316aa8 MIPS: Print the actual detected I-cache associativity on bootup.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-05-14 13:50:25 +01:00
Manuel Lauss 270717a8a0 MIPS: Alchemy: unify CPU model constants.
This patch removes the various CPU_AU1??? model constants in favor of
a single CPU_ALCHEMY one.

All currently existing Alchemy models are identical in terms of cpu
core and cache size/organization.  The parts of the mips kernel which
need to know the exact CPU revision extract it from the c0_prid register
already; and finally nothing else in-tree depends on those any more.

Should a new variant with slightly different "company options" and/or
"processor revision" bits in c0_prid appear, it will be supported
immediately (minus an exact model string in cpuinfo).

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-03-30 14:49:45 +02:00
Shinya Kuribayashi 5864810bc5 MIPS: VR5500: Enable prefetch
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-03-23 23:38:04 +01:00
Ralf Baechle a8ca8b64e3 MIPS: Avoid destructive invalidation on partial cachelines.
See discussion e9c3a7c20901051031y528d0d31r18d44c5096c59e0@mail.gmail.com.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-01-30 21:32:57 +00:00
Thomas Bogendoerfer e0cee3eea7 [MIPS] Fix WARNING: at kernel/smp.c:290
trap_init issues flush_icache_range(), which uses ipi functions to
get icache flushing done on all cpus. But this is done before interrupts
are enabled and caused WARN_ON messages. This changeset introduces
a new local_flush_icache_range() and uses it before interrupts (and
additional CPUs) are enabled to avoid this problem.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-09-05 21:24:11 +01:00
Jens Axboe 8691e5a8f6 smp_call_function: get rid of the unused nonatomic/retry argument
It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-26 11:24:35 +02:00
Ralf Baechle c9c5023d83 [MIPS] Fix buggy use of kmap_coherent.
Assuming the call of kmap_coherent in local_r4k_flush_cache_page doesn't
need fixing this was skipped in fcae549295bcae801ac48fc1c2030ab8cc487020.
Turns out it needed the same change after all.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-06-16 15:14:48 +01:00
Ralf Baechle 89052bd7b3 [MIPS] Fix build for PNX platforms.
Build error was caused by commit 351336929c.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-06-16 15:14:47 +01:00
Ralf Baechle 39b8d52542 [MIPS] Add support for MIPS CMP platform.
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-04-28 17:14:26 +01:00
Chris Dearman 351336929c [MIPS] Allow setting of the cache attribute at run time.
Slightly tacky, but there is a precedent in the sparc archirecture code.

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-04-28 17:14:25 +01:00
Ralf Baechle 9c5a3d729c [MIPS] Handle aliases in vmalloc correctly.
flush_cache_vmap / flush_cache_vunmap were calling flush_cache_all which -
having been deprecated - turned into a nop ...

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-04-07 22:31:04 +01:00
Ralf Baechle 234fcd1484 [MIPS] Fix loads of section missmatches
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-03-12 14:14:41 +00:00
Ralf Baechle 2eaa7ec286 [MIPS] Handle I-cache coherency in flush_cache_range()
So far flush_cache_range() did't consider the I-cache largely because it
did rarely ever matter to real world code.  This was working primarily
because normally code and data are don't share the same pages - with the
exception of MIPS16 code which uses address constants embedded between
the code.   The following sequence of events may break the code:

 o MIPS16 executable being loaded
 o dynamic linker relocates the address constants embedded into the code:
 o   Uses mprotect(2) to make code pages PROT_READ|PROT_WRITE
 o   Performs the actual relocations by writing to the pages which likely
     are COW.  Because no PROT_EXEC is set I-cache coherence will not be
     considered.
 o   Uses mprotect(2) to switch code pages back to PROT_READ|PROT_EXEC.
     This results in a call to flush_cache_range() which also does not
     consider I-caches.
 o => executing the page just having been relocated may now result in the
   I-cache getting refilled with stale data from memory.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-02-19 17:01:31 +00:00
Joe Perches 603e82edf7 arch/mips/: Spelling fixes
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2008-02-03 16:54:53 +02:00
Manuel Lauss 237cfee1db [MIPS] Alchemy: Au1210/Au1250 CPU support
This patch adds IDs for new Au1200 variants: Au1210 and Au1250.
They are essentially identical to the Au1200 except for the Au1210
which has a different SoC-ID in the PRId register [bits 31:24].
The Au1250 is a "Au1200 V0.2".

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29 10:14:59 +00:00
Thomas Bogendoerfer e9c33572a9 [MIPS] Use real cache invalidate
R10k non coherent machines need a real dma cache invalidate to get rid of
speculative stores in cache.  For other machines this promises a slight
speedup.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29 10:14:57 +00:00
Ralf Baechle 33202349ef [MIPS] Remove useless S-cache flushes.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29 10:14:56 +00:00
Ralf Baechle 526af35e5d [MIPS] Use pte_present instead of open coded test for _PAGE_PRESENT.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29 10:14:55 +00:00
Ralf Baechle a754f70886 [MIPS] Sibyte: resurrect old cache hack.
The recent switch of the Sibyte SOCs from the processor specific cache
managment code in c-sb1.c to c-r4k.c lost this old hack

    [MIPS] Hack for SB1 cache issues

    Removing flush_icache_page a while ago broke SB1 which was using an empty
    flush_data_cache_page function.  This glues things well enough so a more
    efficient but also more intrusive solution can be found later.

    Signed-Off-By: Thiemo Seufer <ths@networkno.de>
    Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

in the hope it was no longer needed.  As it turns it still is so resurrect
it until there is a better solution.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-11-15 23:21:48 +00:00
Ralf Baechle a76ab5c10d [MIPS] MT: Fix bug in multithreaded kernels.
When GDB writes a breakpoint into address area of inferior process the
kernel needs to invalidate the modified memory in the inferior which
is done by calling flush_cache_page which in turns calls
r4k_flush_cache_page and local_r4k_flush_cache_page for VSMP or SMTC
kernel via r4k_on_each_cpu().

As the VSMP and SMTC SMP kernels for 34K are running on a single shared
caches it is possible to get away without interprocessor function calls.
This optimization is implemented in r4k_on_each_cpu, so
local_r4k_flush_cache_page is only ever called on the local CPU.

This is where the following code in local_r4k_flush_cache_page() strikes:

        /*
         * If ownes no valid ASID yet, cannot possibly have gotten
         * this page into the cache.
         */
        if (cpu_context(smp_processor_id(), mm) == 0)
                return;

On VSMP and SMTC had a function of cpu_context() for each CPU(TC).

So in case another CPU than the CPU executing local_r4k_cache_flush_page
has not accessed the mm but one of the other CPUs has there may be data
to be flushed in the cache yet local_r4k_cache_flush_page will falsely
return leaving the I-cache inconsistent for the breakpoint.

While the issue was discovered with GDB it also exists in
local_r4k_flush_cache_range() and local_r4k_flush_cache().

Fixed by introducing a new function has_valid_asid which on MT kernels
returns true if a mm is active on any processor in the system.

This is relativly expensive since for memory acccesses in that loop
cache misses have to be assumed but it seems the most viable solution
for 2.6.23 and older -stable kernels.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-29 19:35:37 +00:00