[PATCH 1/2] powerpc/perf: Revert to original NO_SIPR logic

[PATCH 1/2] powerpc/perf: Revert to original NO_SIPR logic

[Michael Ellerman]

This is a revert and then some of commit 860aad7 "Add regs_no_sipr()".
This workaround was only needed on early chip versions.

As before NO_SIPR becomes a static flag of the PMU struct.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
 arch/powerpc/perf/core-book3s.c |   30 ++++++------------------------
 1 file changed, 6 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 426180b..b2f873b 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -110,7 +110,7 @@ static inline void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) {}
 
 static bool regs_use_siar(struct pt_regs *regs)
 {
-	return !!(regs->result & 1);
+	return !!regs->result;
 }
 
 /*
@@ -181,11 +181,6 @@ static bool regs_sipr(struct pt_regs *regs)
 	return !!(regs->dsisr & sipr);
 }
 
-static bool regs_no_sipr(struct pt_regs *regs)
-{
-	return !!(regs->result & 2);
-}
-
 static inline u32 perf_flags_from_msr(struct pt_regs *regs)
 {
 	if (regs->msr & MSR_PR)
@@ -208,7 +203,7 @@ static inline u32 perf_get_misc_flags(struct pt_regs *regs)
 	 * SIAR which should give slightly more reliable
 	 * results
 	 */
-	if (regs_no_sipr(regs)) {
+	if (ppmu->flags & PPMU_NO_SIPR) {
 		unsigned long siar = mfspr(SPRN_SIAR);
 		if (siar >= PAGE_OFFSET)
 			return PERF_RECORD_MISC_KERNEL;
@@ -239,22 +234,9 @@ static inline void perf_read_regs(struct pt_regs *regs)
 	int use_siar;
 
 	regs->dsisr = mmcra;
-	regs->result = 0;
-
-	if (ppmu->flags & PPMU_NO_SIPR)
-		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 (ppmu->flags & PPMU_HAS_SIER)
+		regs->dar = mfspr(SPRN_SIER);
 
 	/*
 	 * If this isn't a PMU exception (eg a software event) the SIAR is
@@ -279,12 +261,12 @@ static inline void perf_read_regs(struct pt_regs *regs)
 		use_siar = 1;
 	else if ((ppmu->flags & PPMU_NO_CONT_SAMPLING))
 		use_siar = 0;
-	else if (!regs_no_sipr(regs) && regs_sipr(regs))
+	else if (!(ppmu->flags & PPMU_NO_SIPR) && regs_sipr(regs))
 		use_siar = 0;
 	else
 		use_siar = 1;
 
-	regs->result |= use_siar;
+	regs->result = use_siar;
 }
 
 /*
-- 
1.7.10.4

[PATCH 2/2] powerpc/perf: Add missing SIER support

[Michael Ellerman]

Commit 8f61aa3 "Add support for SIER" missed updates to siar_valid()
and perf_get_data_addr().

In both cases we need to check the SIER instead of mmcra.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
 arch/powerpc/perf/core-book3s.c |   37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index b2f873b..845c867 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -136,22 +136,30 @@ static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
  * If we're not doing instruction sampling, give them the SDAR
  * (sampled data address).  If we are doing instruction sampling, then
  * only give them the SDAR if it corresponds to the instruction
- * pointed to by SIAR; this is indicated by the [POWER6_]MMCRA_SDSYNC or
- * the [POWER7P_]MMCRA_SDAR_VALID bit in MMCRA.
+ * pointed to by SIAR; this is indicated by the [POWER6_]MMCRA_SDSYNC, the
+ * [POWER7P_]MMCRA_SDAR_VALID bit in MMCRA, or the SDAR_VALID bit in SIER.
  */
 static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp)
 {
 	unsigned long mmcra = regs->dsisr;
-	unsigned long sdsync;
+	bool sdar_valid;
 
-	if (ppmu->flags & PPMU_SIAR_VALID)
-		sdsync = POWER7P_MMCRA_SDAR_VALID;
-	else if (ppmu->flags & PPMU_ALT_SIPR)
-		sdsync = POWER6_MMCRA_SDSYNC;
-	else
-		sdsync = MMCRA_SDSYNC;
+	if (ppmu->flags & PPMU_HAS_SIER)
+		sdar_valid = regs->dar & SIER_SDAR_VALID;
+	else {
+		unsigned long sdsync;
+
+		if (ppmu->flags & PPMU_SIAR_VALID)
+			sdsync = POWER7P_MMCRA_SDAR_VALID;
+		else if (ppmu->flags & PPMU_ALT_SIPR)
+			sdsync = POWER6_MMCRA_SDSYNC;
+		else
+			sdsync = MMCRA_SDSYNC;
 
-	if (!(mmcra & MMCRA_SAMPLE_ENABLE) || (mmcra & sdsync))
+		sdar_valid = mmcra & sdsync;
+	}
+
+	if (!(mmcra & MMCRA_SAMPLE_ENABLE) || sdar_valid)
 		*addrp = mfspr(SPRN_SDAR);
 }
 
@@ -290,8 +298,13 @@ static inline int siar_valid(struct pt_regs *regs)
 	unsigned long mmcra = regs->dsisr;
 	int marked = mmcra & MMCRA_SAMPLE_ENABLE;
 
-	if ((ppmu->flags & PPMU_SIAR_VALID) && marked)
-		return mmcra & POWER7P_MMCRA_SIAR_VALID;
+	if (marked) {
+		if (ppmu->flags & PPMU_HAS_SIER)
+			return regs->dar & SIER_SIAR_VALID;
+
+		if (ppmu->flags & PPMU_SIAR_VALID)
+			return mmcra & POWER7P_MMCRA_SIAR_VALID;
+	}
 
 	return 1;
 }
-- 
1.7.10.4