linux-stable.git/arch/xtensa/kernel, branch linux-3.4.y

xtensa: fix a6 and a7 handling in fast_syscall_xtensa

2014-09-25T03:49:12+00:00

commit d1b6ba82a50cecf94be540a3a153aa89d97511a0 upstream.

Remove restoring a6 on some return paths and instead modify and restore
it in a single place, using symbolic name.
Correctly restore a7 from PT_AREG7 in case of illegal a6 value.

Signed-off-by: Max Filippov 
Signed-off-by: Zefan Li

xtensa: fix TLBTEMP_BASE_2 region handling in fast_second_level_miss

2014-09-25T03:49:12+00:00

commit 7128039fe2dd3d59da9e4ffa036f3aaa3ba87b9f upstream.

Current definition of TLBTEMP_BASE_2 is always 32K above the
TLBTEMP_BASE_1, whereas fast_second_level_miss handler for the TLBTEMP
region analyzes virtual address bit (PAGE_SHIFT + DCACHE_ALIAS_ORDER)
to determine TLBTEMP region where the fault happened. The size of the
TLBTEMP region is also checked incorrectly: not 64K, but twice data
cache way size (whicht may as well be less than the instruction cache
way size).

Fix TLBTEMP_BASE_2 to be TLBTEMP_BASE_1 + data cache way size.
Provide TLBTEMP_SIZE that is a greater of doubled data cache way size or
the instruction cache way size, and use it to determine if the second
level TLB miss occured in the TLBTEMP region.

Practical occurence of page faults in the TLBTEMP area is extremely
rare, this code can be tested by deletion of all w[di]tlb instructions
in the tlbtemp_mapping region.

Signed-off-by: Max Filippov 
Signed-off-by: Zefan Li

xtensa: fix address checks in dma_{alloc,free}_coherent

2014-09-25T03:49:12+00:00

commit 1ca49463c44c970b1ab1d71b0f268bfdf8427a7e upstream.

Virtual address is translated to the XCHAL_KSEG_CACHED region in the
dma_free_coherent, but is checked to be in the 0...XCHAL_KSEG_SIZE
range.

Change check for end of the range from 'addr >= X' to 'addr > X - 1' to
handle the case of X == 0.

Replace 'if (C) BUG();' construct with 'BUG_ON(C);'.

Signed-off-by: Alan Douglas 
Signed-off-by: Max Filippov 
Signed-off-by: Zefan Li

xtensa: don't use alternate signal stack on threads

2013-11-13T03:01:49+00:00

commit cba9a90053e3b7973eff4f1946f33032e98eeed5 upstream.

According to create_thread(3): "The new thread does not inherit the creating
thread's alternate signal stack". Since commit f9a3879a (Fix sigaltstack
corruption among cloned threads), current->sas_ss_size is set to 0 for cloned
processes sharing VM with their parent. Don't use the (nonexistent) alternate
signal stack in this case. This has been broken since commit 29c4dfd9 ([XTENSA]
Remove non-rt signal handling).

Fixes the SA_ONSTACK part of the nptl/tst-cancel20 test from uClibc.

Signed-off-by: Baruch Siach 
Signed-off-by: Max Filippov 
Signed-off-by: Chris Zankel 
Signed-off-by: Greg Kroah-Hartman

xtensa: replace xtensa-specific _f{data,text} by _s{data,text}

2013-08-20T15:26:29+00:00

commit 5e7b6ed8e9bf3c8e3bb579fd0aec64f6526f8c81 upstream.

commit a2d063ac216c161 ("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 
Cc: Steven Rostedt 
Cc: Chris Zankel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

xtensa: fix linker script transformation for .text.unlikely

2013-08-20T15:26:29+00:00

commit f6a03a12ecdbe0dd80a55f6df3b7206c5a403a49 upstream.

Now that binutils generate *.unlikely sections which don't follow
documented (info as) literal section naming rules, section name
transformation script doesn't work well resulting in the following
errors at vmlinux link time:

	main.c:(.text.unlikely+0x3): dangerous relocation: l32r: literal
				     placed after use: .literal.unlikely

Fix section name transformation script by adding specific rule for
.text.unlikely sections.

Signed-off-by: Max Filippov 
Signed-off-by: Chris Zankel 
Cc: Geert Uytterhoeven 
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

xtensa: Add missing RCU idle APIs on idle loop

2012-10-12T20:38:54+00:00

commit 11ad47a0edbd62bfc0547cfcdf227a911433f207 upstream.

In the old times, the whole idle task was considered
as an RCU quiescent state. But as RCU became more and
more successful overtime, some RCU read side critical
section have been added even in the code of some
architectures idle tasks, for tracing for example.

So nowadays, rcu_idle_enter() and rcu_idle_exit() must
be called by the architecture to tell RCU about the part
in the idle loop that doesn't make use of rcu read side
critical sections, typically the part that puts the CPU
in low power mode.

This is necessary for RCU to find the quiescent states in
idle in order to complete grace periods.

Add this missing pair of calls in the xtensa's idle loop.

Reported-by: Paul E. McKenney 
Signed-off-by: Frederic Weisbecker 
Cc: Chris Zankel 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett 
Signed-off-by: Greg Kroah-Hartman

xtensa: fix build failure in xtensa/kernel/signal.c

2012-04-23T16:24:55+00:00

Caused by commit 3785006ac3c8941feb63097c416de92114a6bc39

    "xtensa: don't mask signals if we fail to setup signal stack"

It assigns a return value to "ret", but there is no such variable
anywhere in scope.  Create one.

Cc: Oleg Nesterov 
Cc: Chris Zankel 
Acked-by: Matt Fleming 
Signed-off-by: Paul Gortmaker

Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

2012-03-28T22:58:21+00:00

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...

Disintegrate asm/system.h for Xtensa

2012-03-28T17:30:03+00:00

Disintegrate asm/system.h for Xtensa.

Signed-off-by: David Howells 
cc: Chris Zankel