[tip:perfcounters/core] perf_counter: powerpc: Fix event alternative code generation on POWER5/5+

From: tip-bot for Paul Mackerras
Date: Wed Jun 03 2009 - 05:52:22 EST


Commit-ID: 6984efb692e97ce5f75f26e595685c04c2061bac
Gitweb: http://git.kernel.org/tip/6984efb692e97ce5f75f26e595685c04c2061bac
Author: Paul Mackerras <paulus@xxxxxxxxx>
AuthorDate: Wed, 3 Jun 2009 19:38:58 +1000
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Wed, 3 Jun 2009 11:49:52 +0200

perf_counter: powerpc: Fix event alternative code generation on POWER5/5+

Commit ef923214 ("perf_counter: powerpc: use u64 for event
codes internally") introduced a bug where the return value from
function find_alternative_bdecode gets put into a u64 variable
and later tested to see if it is < 0. The effect is that we
get extra, bogus event code alternatives on POWER5 and POWER5+,
leading to error messages such as "oops compute_mmcr failed"
being printed and counters not counting properly.

This fixes it by using s64 for the return type of
find_alternative_bdecode and for the local variable that the
caller puts the value in. It also makes the event argument a
u64 on POWER5+ for consistency.

Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: John Kacur <jkacur@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxxxxxx>
LKML-Reference: <18982.17586.666132.90983@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
arch/powerpc/kernel/power5+-pmu.c | 4 ++--
arch/powerpc/kernel/power5-pmu.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/power5+-pmu.c b/arch/powerpc/kernel/power5+-pmu.c
index c6cdfc1..8471e3c 100644
--- a/arch/powerpc/kernel/power5+-pmu.c
+++ b/arch/powerpc/kernel/power5+-pmu.c
@@ -242,7 +242,7 @@ static const unsigned char bytedecode_alternatives[4][4] = {
* event code for those that do, or -1 otherwise. This also handles
* alternative PCMSEL values for add events.
*/
-static int find_alternative_bdecode(unsigned int event)
+static s64 find_alternative_bdecode(u64 event)
{
int pmc, altpmc, pp, j;

@@ -277,7 +277,7 @@ static int power5p_get_alternatives(u64 event, unsigned int flags, u64 alt[])
{
int i, j, nalt = 1;
int nlim;
- u64 ae;
+ s64 ae;

alt[0] = event;
nalt = 1;
diff --git a/arch/powerpc/kernel/power5-pmu.c b/arch/powerpc/kernel/power5-pmu.c
index d534496..1b44c5f 100644
--- a/arch/powerpc/kernel/power5-pmu.c
+++ b/arch/powerpc/kernel/power5-pmu.c
@@ -250,7 +250,7 @@ static const unsigned char bytedecode_alternatives[4][4] = {
* PMCSEL values on other counters. This returns the alternative
* event code for those that do, or -1 otherwise.
*/
-static u64 find_alternative_bdecode(u64 event)
+static s64 find_alternative_bdecode(u64 event)
{
int pmc, altpmc, pp, j;

@@ -272,7 +272,7 @@ static u64 find_alternative_bdecode(u64 event)
static int power5_get_alternatives(u64 event, unsigned int flags, u64 alt[])
{
int i, j, nalt = 1;
- u64 ae;
+ s64 ae;

alt[0] = event;
nalt = 1;
--
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