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  1. 22 6月, 2015 2 次提交
  3. 10 4月, 2015 1 次提交
  5. 01 4月, 2015 1 次提交
  7. 20 3月, 2015 1 次提交
  9. 18 3月, 2015 1 次提交
    • S
      MIPS: Rearrange PTE bits into fixed positions. · be0c37c9
      由 Steven J. Hill 提交于 
      This patch rearranges the PTE bits into fixed positions for R2
and later cores. In the past, the TLB handling code did runtime
checking of RI/XI and adjusted the shifts and rotates in order
to fit the largest PFN value into the PTE. The checking now
occurs when building the TLB handler, thus eliminating those
checks. These new arrangements also define the largest possible
PFN value that can fit in the PTE. HUGE page support is only
available for 64-bit cores. Layouts of the PTE bits are now:

   64-bit, R1 or earlier:     CCC D V G [S H] M A W R P
   32-bit, R1 or earler:      CCC D V G M A W R P
   64-bit, R2 or later:       CCC D V G RI/R XI [S H] M A W P
   32-bit, R2 or later:       CCC D V G RI/R XI M A W P

[ralf@linux-mips.org: Fix another build error *rant* *rant*]
Signed-off-by: NSteven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9353/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      be0c37c9
  11. 17 2月, 2015 1 次提交
  13. 16 2月, 2015 1 次提交
  15. 28 11月, 2014 1 次提交
  17. 25 11月, 2014 1 次提交
  19. 23 10月, 2014 1 次提交
    • D
      MIPS: tlbex: Properly fix HUGE TLB Refill exception handler · 9e0f162a
      由 David Daney 提交于 
      In commit 8393c524 (MIPS: tlbex: Fix a missing statement for
HUGETLB), the TLB Refill handler was fixed so that non-OCTEON targets
would work properly with huge pages.  The change was incorrect in that
it broke the OCTEON case.

The problem is shown here:

    xxx0:	df7a0000 	ld	k0,0(k1)
    .
    .
    .
    xxxc0:	df610000 	ld	at,0(k1)
    xxxc4:	335a0ff0 	andi	k0,k0,0xff0
    xxxc8:	e825ffcd 	bbit1	at,0x5,0x0
    xxxcc:	003ad82d 	daddu	k1,at,k0
    .
    .
    .

In the non-octeon case there is a destructive test for the huge PTE
bit, and then at 0, $k0 is reloaded (that is what the 8393c524
patch added).

In the octeon case, we modify k1 in the branch delay slot, but we
never need k0 again, so the new load is not needed, but since k1 is
modified, if we do the load, we load from a garbage location and then
get a nested TLB Refill, which is seen in userspace as either SIGBUS
or SIGSEGV (depending on the garbage).

The real fix is to only do this reloading if it is needed, and never
where it is harmful.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8151/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      9e0f162a
  21. 02 8月, 2014 3 次提交
    • L
      MIPS: Use dedicated exception handler if CPU supports RI/XI exceptions · 5890f70f
      由 Leonid Yegoshin 提交于 
      Use the regular tlb_do_page_fault_0 (no write) handler to handle
the RI and XI exceptions. Also skip the RI/XI validation check
on TLB load handler since it's redundant when the CPU has
unique RI/XI exceptions.
Singed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7339/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      5890f70f
    • M
      MIPS: mm: Use the Hardware Page Table Walker if the core supports it · f1014d1b
      由 Markos Chandras 提交于 
      The Hardware Page Table Walker aims to speed up TLB refill exceptions
by handling them in the hardware level instead of having a software
TLB refill handler. However, a TLB refill exception can still be
thrown in certain cases such as, synchronus exceptions, or address
translation or memory errors during the HTW operation. As a result of
which, HTW must not be considered a complete replacement for the TLB
refill software handler, but rather a fast-path for it.
For HTW to work, the PWBase register must contain the task's page
global directory address so the HTW will kick in on TLB refill
exceptions.

Due to HTW being a separate engine embedded deep in the CPU pipeline,
we need to restart the HTW everytime a PTE changes to avoid HTW
fetching a old entry from the page tables. It's also necessary to
restart the HTW on context switches to prevent it from fetching a
page from the previous process. Finally, since HTW is using the
entryhi register to write the translations to the TLB, it's necessary
to stop the HTW whenever the entryhi changes (eg for tlb probe
perations) and enable it back afterwards.

== Performance ==

The following trivial test was used to measure the performance of the
HTW. Using the same root filesystem, the following command was used
to measure the number of tlb refill handler executions with and
without (using 'nohtw' kernel parameter) HTW support.  The kernel was
modified to use a scratch register as a counter for the TLB refill
exceptions.

find /usr -type f -exec ls -lh {} \;

HTW Enabled:
TLB refill exceptions: 12306

HTW Disabled:
TLB refill exceptions: 17805
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/7336/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      f1014d1b
    • L
      MIPS: bugfix: missed cache flush of TLB refill handler · 1062080a
      由 Leonid Yegoshin 提交于 
      Commit

    Commit 1d40cfcd
    Author: Ralf Baechle <ralf@linux-mips.org>
    Date:   Fri Jul 15 15:23:23 2005 +0000

    Avoid SMP cacheflushes.  This is a minor optimization of startup but
    will also avoid smp_call_function from doing stupid things when called
    from a CPU that is not yet marked online.

missed an appropriate cache flush of TLB refill handler because that time it was
at fixed location CAC_BASE. After years the refill handler in EBASE vector
is not at that location and can be allocated in some another memory and needs
I-cache sync as other TLB exception vectors.

Besides that, the new function - local_flash_icache_range() was introduced
to avoid SMP cacheflushes.
Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: paul.gortmaker@windriver.com
Cc: jchandra@broadcom.com
Cc: linux-kernel@vger.kernel.org
Cc: david.daney@cavium.com
Patchwork: https://patchwork.linux-mips.org/patch/7312/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      1062080a
  23. 30 7月, 2014 1 次提交
  25. 02 6月, 2014 1 次提交
  27. 31 5月, 2014 1 次提交
  29. 15 5月, 2014 1 次提交
  31. 01 4月, 2014 2 次提交
  33. 27 3月, 2014 2 次提交
  35. 07 3月, 2014 1 次提交
  37. 25 1月, 2014 1 次提交
  39. 23 1月, 2014 1 次提交
  41. 30 10月, 2013 3 次提交
  43. 18 9月, 2013 1 次提交
  45. 26 8月, 2013 1 次提交
  47. 19 7月, 2013 2 次提交
  49. 15 7月, 2013 1 次提交
    • P
      MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code · 078a55fc
      由 Paul Gortmaker 提交于 
      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 5e427ec2 ("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: NPaul 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: NRalf Baechle <ralf@linux-mips.org>
      078a55fc
  51. 01 7月, 2013 2 次提交
  53. 27 6月, 2013 1 次提交
  55. 25 6月, 2013 1 次提交
    • J
      MIPS: Flush TLB handlers directly after writing them · a3d9086b
      由 Jonas Gorski 提交于 
      When having enabled MIPS_PGD_C0_CONTEXT, trap_init() might call the
generated tlbmiss_handler_setup_pgd before it was committed to memory,
causing boot failures:

  trap_init()
   |- per_cpu_trap_init()
   |   |- TLBMISS_HANDLER_SETUP()
   |       |- tlbmiss_handler_setup_pgd()
   |- flush_tlb_handlers()

To avoid this, move flush_tlb_handlers() into build_tlb_refill_handler()
right after they were generated. We can do this as the cache handling is
initialized just before creating the tlb handlers.

This issue was introduced in 3d8bfdd0
("MIPS: Use C0_KScratch (if present) to hold PGD pointer.").
Signed-off-by: NJonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Jayachandran C <jchandra@broadcom.com>
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/5539/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      a3d9086b
  57. 22 6月, 2013 1 次提交
  59. 13 6月, 2013 2 次提交