[PATCH 4/6] perf, x86: Move MSR address offset calculation to architecture specific files

[Jacob Shin <jacob.shin@amd.com>]

Move counter index to MSR address offset calculation to architecture
specific files. This prepares the way for perf_event_amd to enable
counter addresses that are not contiguous -- for example AMD Family
15h processors have 6 core performance counters starting at 0xc0010200
and 4 northbridge performance counters starting at 0xc0010240.

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
---
 arch/x86/kernel/cpu/perf_event.h     |   21 ++++-------------
 arch/x86/kernel/cpu/perf_event_amd.c |   42 ++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 115c1ea..015826e 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -325,6 +325,7 @@ struct x86_pmu {
 	int		(*schedule_events)(struct cpu_hw_events *cpuc, int n, int *assign);
 	unsigned	eventsel;
 	unsigned	perfctr;
+	int             (*addr_offset)(int index, int eventsel);
 	u64		(*event_map)(int);
 	int		max_events;
 	int		num_counters;
@@ -446,28 +447,16 @@ extern u64 __read_mostly hw_cache_extra_regs
 
 u64 x86_perf_event_update(struct perf_event *event);
 
-static inline int x86_pmu_addr_offset(int index)
-{
-	int offset;
-
-	/* offset = X86_FEATURE_PERFCTR_CORE ? index << 1 : index */
-	alternative_io(ASM_NOP2,
-		       "shll $1, %%eax",
-		       X86_FEATURE_PERFCTR_CORE,
-		       "=a" (offset),
-		       "a"  (index));
-
-	return offset;
-}
-
 static inline unsigned int x86_pmu_config_addr(int index)
 {
-	return x86_pmu.eventsel + x86_pmu_addr_offset(index);
+	return x86_pmu.eventsel +
+		(x86_pmu.addr_offset ? x86_pmu.addr_offset(index, 1) : index);
 }
 
 static inline unsigned int x86_pmu_event_addr(int index)
 {
-	return x86_pmu.perfctr + x86_pmu_addr_offset(index);
+	return x86_pmu.perfctr +
+		(x86_pmu.addr_offset ? x86_pmu.addr_offset(index, 0) : index);
 }
 
 int x86_setup_perfctr(struct perf_event *event);
diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 0c2cc51..ef1df38 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -132,6 +132,47 @@ static u64 amd_pmu_event_map(int hw_event)
 	return amd_perfmon_event_map[hw_event];
 }
 
+/*
+ * Previously calculated offsets
+ */
+static unsigned int event_offsets[X86_PMC_IDX_MAX] __read_mostly;
+static unsigned int count_offsets[X86_PMC_IDX_MAX] __read_mostly;
+
+/*
+ * Legacy CPUs:
+ *   4 counters starting at 0xc0010000 each offset by 1
+ *
+ * CPUs with core performance counter extensions:
+ *   6 counters starting at 0xc0010200 each offset by 2
+ */
+static inline int amd_pmu_addr_offset(int index, int eventsel)
+{
+	int offset;
+
+	if (!index)
+		return index;
+
+	if (eventsel)
+		offset = event_offsets[index];
+	else
+		offset = count_offsets[index];
+
+	if (offset)
+		return offset;
+
+	if (!cpu_has_perfctr_core)
+		offset = index;
+	else
+		offset = index << 1;
+
+	if (eventsel)
+		event_offsets[index] = offset;
+	else
+		count_offsets[index] = offset;
+
+	return offset;
+}
+
 static int amd_pmu_hw_config(struct perf_event *event)
 {
 	int ret;
@@ -578,6 +619,7 @@ static __initconst const struct x86_pmu amd_pmu = {
 	.schedule_events	= x86_schedule_events,
 	.eventsel		= MSR_K7_EVNTSEL0,
 	.perfctr		= MSR_K7_PERFCTR0,
+	.addr_offset            = amd_pmu_addr_offset,
 	.event_map		= amd_pmu_event_map,
 	.max_events		= ARRAY_SIZE(amd_perfmon_event_map),
 	.num_counters		= AMD64_NUM_COUNTERS,
-- 
1.7.9.5