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authorFrederic Weisbecker2010-05-20 07:47:21 +0200
committerFrederic Weisbecker2010-06-08 23:31:27 +0200
commitb0f82b81fe6bbcf78d478071f33e44554726bc81 (patch)
tree6305c095b927f956a791b9dce687cb94a21718e6 /arch/powerpc
parentx86: Unify dumpstack.h and stacktrace.h (diff)
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perf: Drop the skip argument from perf_arch_fetch_regs_caller
Drop this argument now that we always want to rewind only to the state of the first caller. It means frame pointers are not necessary anymore to reliably get the source of an event. But this also means we need this helper to be a macro now, as an inline function is not an option since we need to know when to provide a default implentation. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/include/asm/perf_event.h12
-rw-r--r--arch/powerpc/kernel/misc.S26
2 files changed, 12 insertions, 26 deletions
diff --git a/arch/powerpc/include/asm/perf_event.h b/arch/powerpc/include/asm/perf_event.h
index e6d4ce69b126..5c16b891d501 100644
--- a/arch/powerpc/include/asm/perf_event.h
+++ b/arch/powerpc/include/asm/perf_event.h
@@ -21,3 +21,15 @@
#ifdef CONFIG_FSL_EMB_PERF_EVENT
#include <asm/perf_event_fsl_emb.h>
#endif
+
+#ifdef CONFIG_PERF_EVENTS
+#include <asm/ptrace.h>
+#include <asm/reg.h>
+
+#define perf_arch_fetch_caller_regs(regs, __ip) \
+ do { \
+ (regs)->nip = __ip; \
+ (regs)->gpr[1] = *(unsigned long *)__get_SP(); \
+ asm volatile("mfmsr %0" : "=r" ((regs)->msr)); \
+ } while (0)
+#endif
diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S
index 22e507c8a556..2d29752cbe16 100644
--- a/arch/powerpc/kernel/misc.S
+++ b/arch/powerpc/kernel/misc.S
@@ -127,29 +127,3 @@ _GLOBAL(__setup_cpu_power7)
_GLOBAL(__restore_cpu_power7)
/* place holder */
blr
-
-/*
- * Get a minimal set of registers for our caller's nth caller.
- * r3 = regs pointer, r5 = n.
- *
- * We only get R1 (stack pointer), NIP (next instruction pointer)
- * and LR (link register). These are all we can get in the
- * general case without doing complicated stack unwinding, but
- * fortunately they are enough to do a stack backtrace, which
- * is all we need them for.
- */
-_GLOBAL(perf_arch_fetch_caller_regs)
- mr r6,r1
- cmpwi r5,0
- mflr r4
- ble 2f
- mtctr r5
-1: PPC_LL r6,0(r6)
- bdnz 1b
- PPC_LL r4,PPC_LR_STKOFF(r6)
-2: PPC_LL r7,0(r6)
- PPC_LL r7,PPC_LR_STKOFF(r7)
- PPC_STL r6,GPR1-STACK_FRAME_OVERHEAD(r3)
- PPC_STL r4,_NIP-STACK_FRAME_OVERHEAD(r3)
- PPC_STL r7,_LINK-STACK_FRAME_OVERHEAD(r3)
- blr