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authorKevin Hilman <khilman@deeprootsystems.com>2013-03-28 22:54:40 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-04-03 17:00:01 +0100
commitb00884802043d9102ecc2abfdc37a7b35b30e52a (patch)
tree634138ea0602f55374fb1d4a5fa453cce17c6683 /arch/arm/kernel/entry-armv.S
parent4fd75911f6970478444eece952dacb2db9d1e5a5 (diff)
downloadlinux-linaro-stable-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.S1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 0f82098c9bfe..2b1de1b2f132 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