perf/x86: Use 0xff as pseudo code for fixed uncore event

Stephane Eranian suggestted using 0xff as pseudo code for fixed
uncore event and using the umask value to determine which of the
fixed events we want to map to. So far there is at most one fixed
counter in a uncore PMU. So just change the definition of
UNCORE_FIXED_EVENT to 0xff.

Suggested-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1340780953-21130-1-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/perf_event_intel_uncore.c

@@ -179,7 +179,7 @@ static struct attribute *snbep_uncore_pcu_formats_attr[] = {
 };
 
 static struct uncore_event_desc snbep_uncore_imc_events[] = {
-	INTEL_UNCORE_EVENT_DESC(clockticks,      "event=0xff,umask=0xff"),
+	INTEL_UNCORE_EVENT_DESC(clockticks,      "event=0xff,umask=0x00"),
 	INTEL_UNCORE_EVENT_DESC(cas_count_read,  "event=0x04,umask=0x03"),
 	INTEL_UNCORE_EVENT_DESC(cas_count_write, "event=0x04,umask=0x0c"),
 	{ /* end: all zeroes */ },
@@ -616,7 +616,7 @@ static struct attribute_group nhm_uncore_format_group = {
 };
 
 static struct uncore_event_desc nhm_uncore_events[] = {
-	INTEL_UNCORE_EVENT_DESC(clockticks,                "event=0xff,umask=0xff"),
+	INTEL_UNCORE_EVENT_DESC(clockticks,                "event=0xff,umask=0x00"),
 	INTEL_UNCORE_EVENT_DESC(qmc_writes_full_any,       "event=0x2f,umask=0x0f"),
 	INTEL_UNCORE_EVENT_DESC(qmc_normal_reads_any,      "event=0x2c,umask=0x0f"),
 	INTEL_UNCORE_EVENT_DESC(qhl_request_ioh_reads,     "event=0x20,umask=0x01"),

arch/x86/kernel/cpu/perf_event_intel_uncore.h

@@ -9,7 +9,7 @@
 
 #define UNCORE_PMU_HRTIMER_INTERVAL	(60 * NSEC_PER_SEC)
 
-#define UNCORE_FIXED_EVENT		0xffff
+#define UNCORE_FIXED_EVENT		0xff
 #define UNCORE_PMC_IDX_MAX_GENERIC	8
 #define UNCORE_PMC_IDX_FIXED		UNCORE_PMC_IDX_MAX_GENERIC
 #define UNCORE_PMC_IDX_MAX		(UNCORE_PMC_IDX_FIXED + 1)