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| author | Kevin Hilman <khilman@deeprootsystems.com> | 2013-03-28 22:54:40 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-04-03 17:00:01 +0100 |
| commit | b00884802043d9102ecc2abfdc37a7b35b30e52a (patch) | |
| tree | 634138ea0602f55374fb1d4a5fa453cce17c6683 /arch/arm/kernel/entry-armv.S | |
| parent | 4fd75911f6970478444eece952dacb2db9d1e5a5 (diff) | |
| download | op-kernel-dev-b00884802043d9102ecc2abfdc37a7b35b30e52a.zip op-kernel-dev-b00884802043d9102ecc2abfdc37a7b35b30e52a.tar.gz | |
ARM: 7688/1: add support for context tracking subsystem
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 <mats.liljegren@enea.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/entry-armv.S')
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 0f82098..2b1de1b 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -396,6 +396,7 @@ ENDPROC(__pabt_svc) #ifdef CONFIG_IRQSOFF_TRACER bl trace_hardirqs_off #endif + ct_user_exit save = 0 .endm .macro kuser_cmpxchg_check |
