linux.git/arch/arm/kernel/entry-header.S, branch v3.16.81

ARM: 8129/1: errata: work around Cortex-A15 erratum 830321 using dummy strex

2014-10-05T20:41:01+00:00

commit 2c32c65e3726c773760038910be30cce1b4d4149 upstream.

On revisions of Cortex-A15 prior to r3p3, a CLREX instruction at PL1 may
falsely trigger a watchpoint exception, leading to potential data aborts
during exception return and/or livelock.

This patch resolves the issue in the following ways:

  - Replacing our uses of CLREX with a dummy STREX sequence instead (as
    we did for v6 CPUs).

  - Removing the clrex code from v7_exit_coherency_flush and derivatives,
    since this only exists as a minor performance improvement when
    non-cached exclusives are in use (Linux doesn't use these).

Benchmarking on a variety of ARM cores revealed no measurable
performance difference with this change applied, so the change is
performed unconditionally and no new Kconfig entry is added.

Signed-off-by: Mark Rutland 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

Merge branches 'alignment', 'fixes', 'l2c' (early part) and 'misc' into for-next

2014-06-05T11:35:52+00:00

ARM: consolidate last remaining open-coded alignment trap enable

2014-06-02T08:20:20+00:00

We can use the alignment_trap assembly macro here too.

Signed-off-by: Russell King

ARM: 8064/1: fix v7-M signal return

2014-05-25T22:44:27+00:00

According to the ARM ARM, the behaviour is UNPREDICTABLE if the PC read
from the exception return stack is not half word aligned.  See the
pseudo code for ExceptionReturn() and PopStack().

The signal handler's address has the bit 0 set, and setup_return()
directly writes this to regs->ARM_pc.  Current hardware happens to
discard this bit, but QEMU's emulation doesn't and this makes processes
crash.  Mask out bit 0 before the exception return in order to get
predictable behaviour.

Fixes: 19c4d593f0b4 ("ARM: ARMv7-M: Add support for exception handling")

Cc: stable@kernel.org
Acked-by: Uwe Kleine-König 
Signed-off-by: Rabin Vincent 
Signed-off-by: Russell King

ARM: 8017/1: Move asm macro get_thread_info to asm/assembler.h

2014-04-09T12:08:07+00:00

asm/assembler.h is a better place for this macro since it is used by
asm files outside arch/arm/kernel/

Signed-off-by: Catalin Marinas 
Tested-by: Arun KS 
Signed-off-by: Russell King

arm: Fix build error with context tracking calls

2013-09-27T15:59:47+00:00

ad65782fba50 (context_tracking: Optimize main APIs off case
with static key) converted context tracking main APIs to inline
function and left ARM asm callers behind.

This can be easily fixed by making ARM calling the post static
keys context tracking function. We just need to replicate the
static key checks there. We'll remove these later when ARM will
support the context tracking static keys.

Reported-by: Guenter Roeck 
Reported-by: Russell King 
Signed-off-by: Frederic Weisbecker 
Tested-by: Kevin Hilman 
Cc: Nicolas Pitre 
Cc: Anil Kumar 
Cc: Tony Lindgren 
Cc: Benoit Cousson 
Cc: Guenter Roeck 
Cc: Russell King 
Cc: Kevin Hilman

Merge branch 'for-next' of git://git.pengutronix.de/git/ukl/linux into devel-stable

2013-05-22T09:52:24+00:00

Pull ARM-v7M support from Uwe Kleine-König:
"All but the last patch were in next since next-20130418 without issues.
The last patch fixes a problem in combination with

  8164f7a (ARM: 7680/1: Detect support for SDIV/UDIV from ISAR0 register)

which triggers a WARN_ON without an implemented read_cpuid_ext.

The branch merges fine into v3.10-rc1 and I'd be happy if you pulled it
for 3.11-rc1. The only missing piece to be able to run a Cortex-M3 is
the irqchip driver that will go in via Thomas Gleixner and platform
specific stuff."

Merge branches 'devel-stable', 'entry', 'fixes', 'mach-types', 'misc' and 'smp-hotplug' into for-linus

2013-05-02T20:30:36+00:00

ARM: ARMv7-M: Add support for exception handling

2013-04-17T19:44:46+00:00

This patch implements the exception handling for the ARMv7-M
architecture (pretty different from the A or R profiles).

It bases on work done earlier by Catalin for 2.6.33 but was nearly
completely rewritten to use a pt_regs layout compatible to the A
profile.

Signed-off-by: Catalin Marinas 
Reviewed-by: Jonathan Austin 
Tested-by: Jonathan Austin 
Signed-off-by: Uwe Kleine-König

ARM: 7688/1: add support for context tracking subsystem

2013-04-03T16:00:01+00:00

commit 91d1aa43 (context_tracking: New context tracking susbsystem)
generalized parts of the RCU userspace extended quiescent state into
the context tracking subsystem.  Context tracking is then used
to implement adaptive tickless (a.k.a extended nohz)

To support the new context tracking subsystem on ARM, the user/kernel
boundary transtions need to be instrumented.

For exceptions and IRQs in usermode, the existing usr_entry macro is
used to instrument the user->kernel transition.  For the return to
usermode path, the ret_to_user* path is instrumented.  Using the
usr_entry macro, this covers interrupts in userspace, data abort and
prefetch abort exceptions in userspace as well as undefined exceptions
in userspace (which is where FP emulation and VFP are handled.)

For syscalls, the slow return path is covered by instrumenting the
ret_to_user path.  In addition, the syscall entry point is
instrumented which covers the user->kernel transition for both fast
and slow syscalls, and an additional instrumentation point is added
for the fast syscall return path (ret_fast_syscall).

Cc: Mats Liljegren 
Cc: Frederic Weisbecker 
Signed-off-by: Kevin Hilman 
Signed-off-by: Russell King