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authorLinus Torvalds <torvalds@linux-foundation.org>2010-03-26 15:09:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-03-26 15:09:33 -0700
commit6fa41366c1c5e8b9640baba22d2b90ec9035a889 (patch)
treead3b2214e0c5d4774f200ab7bb08b832babb9468 /arch
parent309d1dcb5b73ab1f8212aff3037a7bcb46afe819 (diff)
parent9eff26ea48bfbe2885b158742a7512a097ec911b (diff)
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Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: powerpc/perf_events: Fix call-graph recording, add perf_arch_fetch_caller_regs perf top: Add missing initialization to zero perf probe: Use original address instead of CU-based address perf probe: Fix offset to allow signed value perf top: Improve the autosizing of column lenghts perf probe: Fix need_dwarf flag if lazy matching is used perf probe: Fix probe_point buffer overrun
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/include/asm/asm-compat.h2
-rw-r--r--arch/powerpc/kernel/misc.S28
2 files changed, 30 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/asm-compat.h b/arch/powerpc/include/asm/asm-compat.h
index c1b475a941e..a9b91ed3d4b 100644
--- a/arch/powerpc/include/asm/asm-compat.h
+++ b/arch/powerpc/include/asm/asm-compat.h
@@ -28,6 +28,7 @@
#define PPC_LLARX(t, a, b, eh) PPC_LDARX(t, a, b, eh)
#define PPC_STLCX stringify_in_c(stdcx.)
#define PPC_CNTLZL stringify_in_c(cntlzd)
+#define PPC_LR_STKOFF 16
/* Move to CR, single-entry optimized version. Only available
* on POWER4 and later.
@@ -51,6 +52,7 @@
#define PPC_STLCX stringify_in_c(stwcx.)
#define PPC_CNTLZL stringify_in_c(cntlzw)
#define PPC_MTOCRF stringify_in_c(mtcrf)
+#define PPC_LR_STKOFF 4
#endif
diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S
index 2d29752cbe1..b485a87c94e 100644
--- a/arch/powerpc/kernel/misc.S
+++ b/arch/powerpc/kernel/misc.S
@@ -127,3 +127,31 @@ _GLOBAL(__setup_cpu_power7)
_GLOBAL(__restore_cpu_power7)
/* place holder */
blr
+
+#ifdef CONFIG_EVENT_TRACING
+/*
+ * 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
+#endif /* CONFIG_EVENT_TRACING */