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/
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>
* '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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
This should help making bug reports for the gadzillion of cores with all
their configuration and synthesis options more useful.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
On MP configurations it's highly dubious what this code will actually
affect since blasting away cachelines may or may not do the right
thing wrt. cache coherency.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
It may not be perfect yet but the SB1 code is badly borken and has
horrible performance issues.
Downside: This seriously breaks support for pass 1 parts of the BCM1250
where indexed cacheops don't work quite reliable but I seem to be the
last one on the planet with a pass 1 part anyway.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
r4k_flush_cache_all() and r4k_flush_cache_mm() case: these are noop if
the CPU did not have dc_aliases. It would mean we do not need to care
about icache here.
r4k_flush_cache_range case: if r4k_flush_cache_mm() did not need to
care about icache, it would be same for this function.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
With more recent compilers inline doesn't necessarily means a function
will always be inlined. So leave that decission to the compiler and
make the function as __init.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
c-r4k.c and c-sb1.c use drop_mmu_context() to flush virtually tagged
I-caches, but this does not work for flushing other task's icache. This
is for example triggered by copy_to_user_page() called from ptrace(2).
Use indexed flush for such cases.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
