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  1. 13 5月, 2016 1 次提交
  3. 03 4月, 2016 1 次提交
  5. 22 6月, 2015 1 次提交
  7. 17 6月, 2015 1 次提交
  9. 16 5月, 2015 1 次提交
  11. 01 4月, 2015 1 次提交
  13. 20 3月, 2015 1 次提交
  15. 20 2月, 2015 1 次提交
  17. 31 1月, 2015 1 次提交
    • D
      MIPS: Fix C0_Pagegrain[IEC] support. · 9ead8632
      由 David Daney 提交于 
      The following commits:

  5890f70f (MIPS: Use dedicated exception handler if CPU supports RI/XI exceptions)
  6575b1d4 (MIPS: kernel: cpu-probe: Detect unique RI/XI exceptions)

break the kernel for *all* existing MIPS CPUs that implement the
CP0_PageGrain[IEC] bit.  They cause the TLB exception handlers to be
generated without the legacy execute-inhibit handling, but never set
the CP0_PageGrain[IEC] bit to activate the use of dedicated exception
vectors for execute-inhibit exceptions.  The result is that upon
detection of an execute-inhibit violation, we loop forever in the TLB
exception handlers instead of sending SIGSEGV to the task.

If we are generating TLB exception handlers expecting separate
vectors, we must also enable the CP0_PageGrain[IEC] feature.

The bug was introduced in kernel version 3.17.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: <stable@vger.kernel.org>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/8880/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      9ead8632
  19. 25 11月, 2014 1 次提交
  21. 20 11月, 2014 1 次提交
  23. 02 8月, 2014 1 次提交
    • 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
  25. 31 7月, 2014 2 次提交
  27. 24 5月, 2014 1 次提交
    • R
      MIPS: MT: Remove SMTC support · b633648c
      由 Ralf Baechle 提交于 
      Nobody is maintaining SMTC anymore and there also seems to be no userbase.
Which is a pity - the SMTC technology primarily developed by Kevin D.
Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT
ASE's power and elegance.

Based on Markos Chandras <Markos.Chandras@imgtec.com> patch
https://patchwork.linux-mips.org/patch/6719/ which while very similar did
no longer apply cleanly when I tried to merge it plus some additional
post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to
merge once upon a time.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      b633648c
  29. 02 5月, 2014 1 次提交
  31. 01 4月, 2014 1 次提交
  33. 23 1月, 2014 3 次提交
  35. 30 10月, 2013 1 次提交
  37. 18 9月, 2013 1 次提交
  39. 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
  41. 17 5月, 2013 1 次提交
  43. 08 5月, 2013 2 次提交
  45. 01 2月, 2013 1 次提交
  47. 12 12月, 2012 2 次提交
  49. 04 12月, 2012 1 次提交
    • D
      MIPS: Avoid mcheck by flushing page range in huge_ptep_set_access_flags() · ac53c4fc
      由 David Daney 提交于 
      Problem:

1) Huge page mapping of anonymous memory is initially invalid.  Will be
   faulted in by copy-on-write mechanism.

2) Userspace attempts store at the end of the huge mapping.

3) TLB Refill exception handler fill TLB with a normal (4K sized)
   invalid page at the end of the huge mapping virtual address range.

4) Userspace restarted, and re-attempts the store at the end of the
   huge mapping.

5) Page from #3 is invalid, we get a fault and go to the hugepage
   fault handler.  This tries to map a huge page and calls
   huge_ptep_set_access_flags() to install the mapping.

6) We just call the generic ptep_set_access_flags() to set up the page
   tables, but the flush there assumes a normal (4K sized) page and
   only tries to flush the first part of the huge page virtual address
   out of the TLB, since the existing entry from step #3 doesn't
   conflict, nothing is flushed.

7) We attempt to load the mapping into the TLB, but because it
   conflicts with the entry from step #3, we get a Machine Check
   exception.

The fix: Flush the entire rage covered by the huge page in
huge_ptep_set_access_flags(), and remove the optimization in
local_flush_tlb_range() so that the flush actually does the correct
thing.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Hillf Danton <dhillf@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/4661/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
(cherry picked from commit dd617f258cc39d36be26afee9912624a2d23112c)
      ac53c4fc
  51. 17 10月, 2012 1 次提交
  53. 14 9月, 2012 1 次提交
  55. 29 3月, 2012 1 次提交
  57. 11 1月, 2012 2 次提交
  59. 08 12月, 2011 1 次提交
  61. 25 10月, 2011 1 次提交
  63. 06 4月, 2011 1 次提交
  65. 27 2月, 2010 2 次提交