[PATCH] powerpc perf events: Fix priority of MSR HV vs PR bits

From: Michael Neuling <mikey@neuling.org>
To: benh@kernel.crashing.org
Cc: linuxppc-dev@ozlabs.org, Paul Mackerras <paulus@samba.org>
Subject: [PATCH] powerpc perf events: Fix priority of MSR HV vs PR bits
Date: Thu, 15 Oct 2009 16:11:57 +1100	[thread overview]
Message-ID: <15714.1255583517@neuling.org> (raw)

The architecture defines that if MSR PR is set we are in problem state
irrespective of the HV bit.  This fixes perf events to reflect this.

Signed-off-by: Michael Neuling <mikey@neuling.org>
CC: paulus@samba.org
---
Tested on PHYP and BML.

This could go back into 31 too with s/event/counters/g.  It only
effects bare metal on server chips, so no biggy if it doesn't.  

 arch/powerpc/kernel/perf_event.c |   17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

Index: linux-2.6-ozlabs/arch/powerpc/kernel/perf_event.c
===================================================================

--- linux-2.6-ozlabs.orig/arch/powerpc/kernel/perf_event.c
+++ linux-2.6-ozlabs/arch/powerpc/kernel/perf_event.c
@@ -116,20 +116,23 @@ static inline void perf_get_data_addr(st
 static inline u32 perf_get_misc_flags(struct pt_regs *regs)
 {
 	unsigned long mmcra = regs->dsisr;
+	unsigned long sihv = MMCRA_SIHV;
+	unsigned long sipr = MMCRA_SIPR;
 
 	if (TRAP(regs) != 0xf00)
 		return 0;	/* not a PMU interrupt */
 
 	if (ppmu->flags & PPMU_ALT_SIPR) {
-		if (mmcra & POWER6_MMCRA_SIHV)
-			return PERF_RECORD_MISC_HYPERVISOR;
-		return (mmcra & POWER6_MMCRA_SIPR) ?
-			PERF_RECORD_MISC_USER : PERF_RECORD_MISC_KERNEL;
+		sihv = POWER6_MMCRA_SIHV;
+		sipr = POWER6_MMCRA_SIPR;
 	}
-	if (mmcra & MMCRA_SIHV)
+
+	/* PR has priority over HV, so order below is important */
+	if (mmcra & sipr)
+		return PERF_RECORD_MISC_USER;
+	if ((mmcra & sihv) && (freeze_events_kernel != MMCR0_FCHV))
 		return PERF_RECORD_MISC_HYPERVISOR;
-	return (mmcra & MMCRA_SIPR) ? PERF_RECORD_MISC_USER :
-		PERF_RECORD_MISC_KERNEL;
+	return PERF_RECORD_MISC_KERNEL;
 }
 
 /*
