perf/x86: Hybrid PMU support for counters

The number of GP and fixed counters are different among hybrid PMUs.
Each hybrid PMU should use its own counter related information.

When handling a certain hybrid PMU, apply the number of counters from
the corresponding hybrid PMU.

When reserving the counters in the initialization of a new event,
reserve all possible counters.

The number of counter recored in the global x86_pmu is for the
architecture counters which are available for all hybrid PMUs. KVM
doesn't support the hybrid PMU yet. Return the number of the
architecture counters for now.

For the functions only available for the old platforms, e.g.,
intel_pmu_drain_pebs_nhm(), nothing is changed.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/1618237865-33448-7-git-send-email-kan.liang@linux.intel.com

1 files changed, 38 insertions, 17 deletions

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 7d3c19ec45fe..1aeb31cb4ee5 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -185,16 +185,29 @@ static DEFINE_MUTEX(pmc_reserve_mutex);
 
 #ifdef CONFIG_X86_LOCAL_APIC
 
+static inline int get_possible_num_counters(void)
+{
+	int i, num_counters = x86_pmu.num_counters;
+
+	if (!is_hybrid())
+		return num_counters;
+
+	for (i = 0; i < x86_pmu.num_hybrid_pmus; i++)
+		num_counters = max_t(int, num_counters, x86_pmu.hybrid_pmu[i].num_counters);
+
+	return num_counters;
+}
+
 static bool reserve_pmc_hardware(void)
 {
-	int i;
+	int i, num_counters = get_possible_num_counters();
 
-	for (i = 0; i < x86_pmu.num_counters; i++) {
+	for (i = 0; i < num_counters; i++) {
 		if (!reserve_perfctr_nmi(x86_pmu_event_addr(i)))
 			goto perfctr_fail;
 	}
 
-	for (i = 0; i < x86_pmu.num_counters; i++) {
+	for (i = 0; i < num_counters; i++) {
 		if (!reserve_evntsel_nmi(x86_pmu_config_addr(i)))
 			goto eventsel_fail;
 	}
@@ -205,7 +218,7 @@ eventsel_fail:
 	for (i--; i >= 0; i--)
 		release_evntsel_nmi(x86_pmu_config_addr(i));
 
-	i = x86_pmu.num_counters;
+	i = num_counters;
 
 perfctr_fail:
 	for (i--; i >= 0; i--)
@@ -216,9 +229,9 @@ perfctr_fail:
 
 static void release_pmc_hardware(void)
 {
-	int i;
+	int i, num_counters = get_possible_num_counters();
 
-	for (i = 0; i < x86_pmu.num_counters; i++) {
+	for (i = 0; i < num_counters; i++) {
 		release_perfctr_nmi(x86_pmu_event_addr(i));
 		release_evntsel_nmi(x86_pmu_config_addr(i));
 	}
@@ -946,6 +959,7 @@ EXPORT_SYMBOL_GPL(perf_assign_events);
 
 int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 {
+	int num_counters = hybrid(cpuc->pmu, num_counters);
 	struct event_constraint *c;
 	struct perf_event *e;
 	int n0, i, wmin, wmax, unsched = 0;
@@ -1021,7 +1035,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 
 	/* slow path */
 	if (i != n) {
-		int gpmax = x86_pmu.num_counters;
+		int gpmax = num_counters;
 
 		/*
 		 * Do not allow scheduling of more than half the available
@@ -1042,7 +1056,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 		 * the extra Merge events needed by large increment events.
 		 */
 		if (x86_pmu.flags & PMU_FL_PAIR) {
-			gpmax = x86_pmu.num_counters - cpuc->n_pair;
+			gpmax = num_counters - cpuc->n_pair;
 			WARN_ON(gpmax <= 0);
 		}
 
@@ -1129,10 +1143,12 @@ static int collect_event(struct cpu_hw_events *cpuc, struct perf_event *event,
  */
 static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
 {
+	int num_counters = hybrid(cpuc->pmu, num_counters);
+	int num_counters_fixed = hybrid(cpuc->pmu, num_counters_fixed);
 	struct perf_event *event;
 	int n, max_count;
 
-	max_count = x86_pmu.num_counters + x86_pmu.num_counters_fixed;
+	max_count = num_counters + num_counters_fixed;
 
 	/* current number of events already accepted */
 	n = cpuc->n_events;
@@ -1499,18 +1515,18 @@ void perf_event_print_debug(void)
 {
 	u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
 	u64 pebs, debugctl;
-	struct cpu_hw_events *cpuc;
+	int cpu = smp_processor_id();
+	struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
+	int num_counters = hybrid(cpuc->pmu, num_counters);
+	int num_counters_fixed = hybrid(cpuc->pmu, num_counters_fixed);
 	unsigned long flags;
-	int cpu, idx;
+	int idx;
 
-	if (!x86_pmu.num_counters)
+	if (!num_counters)
 		return;
 
 	local_irq_save(flags);
 
-	cpu = smp_processor_id();
-	cpuc = &per_cpu(cpu_hw_events, cpu);
-
 	if (x86_pmu.version >= 2) {
 		rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
 		rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
@@ -1533,7 +1549,7 @@ void perf_event_print_debug(void)
 	}
 	pr_info("CPU#%d: active:     %016llx\n", cpu, *(u64 *)cpuc->active_mask);
 
-	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
+	for (idx = 0; idx < num_counters; idx++) {
 		rdmsrl(x86_pmu_config_addr(idx), pmc_ctrl);
 		rdmsrl(x86_pmu_event_addr(idx), pmc_count);
 
@@ -1546,7 +1562,7 @@ void perf_event_print_debug(void)
 		pr_info("CPU#%d:   gen-PMC%d left:  %016llx\n",
 			cpu, idx, prev_left);
 	}
-	for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) {
+	for (idx = 0; idx < num_counters_fixed; idx++) {
 		if (fixed_counter_disabled(idx, cpuc->pmu))
 			continue;
 		rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count);
@@ -2781,6 +2797,11 @@ unsigned long perf_misc_flags(struct pt_regs *regs)
 void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
 {
 	cap->version		= x86_pmu.version;
+	/*
+	 * KVM doesn't support the hybrid PMU yet.
+	 * Return the common value in global x86_pmu,
+	 * which available for all cores.
+	 */
 	cap->num_counters_gp	= x86_pmu.num_counters;
 	cap->num_counters_fixed	= x86_pmu.num_counters_fixed;
 	cap->bit_width_gp	= x86_pmu.cntval_bits;