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authorMichael Ellerman <michael@ellerman.id.au>2013-04-25 19:28:27 (GMT)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-04-26 06:11:10 (GMT)
commit8f61aa325fab3a40b7c847bd35601ad99d7959c9 (patch)
treea778e0cdef0a9bf3138246fe56817125282e9eeb /arch/powerpc/perf
parent860aad71fc7022e5a3907afe50fd96a11e546802 (diff)
powerpc/perf: Add support for SIER
On power8 we have a new SIER (Sampled Instruction Event Register), which captures information about instructions when we have random sampling enabled. Add support for loading the SIER into pt_regs, overloading regs->dar. Also set the new NO_SIPR flag in regs->result if we don't have SIPR. Update regs_sihv/sipr() to look for SIPR/SIHV in SIER. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/perf')
-rw-r--r--arch/powerpc/perf/core-book3s.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 1c13c3d..4ac6e64 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -140,6 +140,9 @@ static bool regs_sihv(struct pt_regs *regs)
{
unsigned long sihv = MMCRA_SIHV;
+ if (ppmu->flags & PPMU_HAS_SIER)
+ return !!(regs->dar & SIER_SIHV);
+
if (ppmu->flags & PPMU_ALT_SIPR)
sihv = POWER6_MMCRA_SIHV;
@@ -150,6 +153,9 @@ static bool regs_sipr(struct pt_regs *regs)
{
unsigned long sipr = MMCRA_SIPR;
+ if (ppmu->flags & PPMU_HAS_SIER)
+ return !!(regs->dar & SIER_SIPR);
+
if (ppmu->flags & PPMU_ALT_SIPR)
sipr = POWER6_MMCRA_SIPR;
@@ -203,6 +209,7 @@ static inline u32 perf_get_misc_flags(struct pt_regs *regs)
/*
* Overload regs->dsisr to store MMCRA so we only need to read it once
* on each interrupt.
+ * Overload regs->dar to store SIER if we have it.
* Overload regs->result to specify whether we should use the MSR (result
* is zero) or the SIAR (result is non zero).
*/
@@ -219,6 +226,18 @@ static inline void perf_read_regs(struct pt_regs *regs)
regs->result |= 2;
/*
+ * On power8 if we're in random sampling mode, the SIER is updated.
+ * If we're in continuous sampling mode, we don't have SIPR.
+ */
+ if (ppmu->flags & PPMU_HAS_SIER) {
+ if (marked)
+ regs->dar = mfspr(SPRN_SIER);
+ else
+ regs->result |= 2;
+ }
+
+
+ /*
* If this isn't a PMU exception (eg a software event) the SIAR is
* not valid. Use pt_regs.
*

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