perf/x86: Hybrid PMU support for extra_regs

Different hybrid PMU may have different extra registers, e.g. Core PMU
may have offcore registers, frontend register and ldlat register. Atom
core may only have offcore registers and ldlat register. Each hybrid PMU
should use its own extra_regs.

An Intel Hybrid system should always have extra registers.
Unconditionally allocate shared_regs for Intel Hybrid system.

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/1618237865-33448-11-git-send-email-kan.liang@linux.intel.com

arch/x86/events/core.c

@@ -154,15 +154,16 @@ u64 x86_perf_event_update(struct perf_event *event)
  */
 static int x86_pmu_extra_regs(u64 config, struct perf_event *event)
 {
+	struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs);
 	struct hw_perf_event_extra *reg;
 	struct extra_reg *er;
 
 	reg = &event->hw.extra_reg;
 
-	if (!x86_pmu.extra_regs)
+	if (!extra_regs)
 		return 0;
 
-	for (er = x86_pmu.extra_regs; er->msr; er++) {
+	for (er = extra_regs; er->msr; er++) {
 		if (er->event != (config & er->config_mask))
 			continue;
 		if (event->attr.config1 & ~er->valid_mask)

arch/x86/events/intel/core.c

@@ -2966,8 +2966,10 @@ intel_vlbr_constraints(struct perf_event *event)
 	return NULL;
 }
 
-static int intel_alt_er(int idx, u64 config)
+static int intel_alt_er(struct cpu_hw_events *cpuc,
+			int idx, u64 config)
 {
+	struct extra_reg *extra_regs = hybrid(cpuc->pmu, extra_regs);
 	int alt_idx = idx;
 
 	if (!(x86_pmu.flags & PMU_FL_HAS_RSP_1))
@@ -2979,23 +2981,24 @@ static int intel_alt_er(int idx, u64 config)
 	if (idx == EXTRA_REG_RSP_1)
 		alt_idx = EXTRA_REG_RSP_0;
 
-	if (config & ~x86_pmu.extra_regs[alt_idx].valid_mask)
+	if (config & ~extra_regs[alt_idx].valid_mask)
 		return idx;
 
 	return alt_idx;
 }
 
 static void intel_fixup_er(struct perf_event *event, int idx)
 {
+	struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs);
 	event->hw.extra_reg.idx = idx;
 
 	if (idx == EXTRA_REG_RSP_0) {
 		event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
-		event->hw.config |= x86_pmu.extra_regs[EXTRA_REG_RSP_0].event;
+		event->hw.config |= extra_regs[EXTRA_REG_RSP_0].event;
 		event->hw.extra_reg.reg = MSR_OFFCORE_RSP_0;
 	} else if (idx == EXTRA_REG_RSP_1) {
 		event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
-		event->hw.config |= x86_pmu.extra_regs[EXTRA_REG_RSP_1].event;
+		event->hw.config |= extra_regs[EXTRA_REG_RSP_1].event;
 		event->hw.extra_reg.reg = MSR_OFFCORE_RSP_1;
 	}
 }
@@ -3071,7 +3074,7 @@ __intel_shared_reg_get_constraints(struct cpu_hw_events *cpuc,
 		 */
 		c = NULL;
 	} else {
-		idx = intel_alt_er(idx, reg->config);
+		idx = intel_alt_er(cpuc, idx, reg->config);
 		if (idx != reg->idx) {
 			raw_spin_unlock_irqrestore(&era->lock, flags);
 			goto again;
@@ -4155,7 +4158,7 @@ int intel_cpuc_prepare(struct cpu_hw_events *cpuc, int cpu)
 {
 	cpuc->pebs_record_size = x86_pmu.pebs_record_size;
 
-	if (x86_pmu.extra_regs || x86_pmu.lbr_sel_map) {
+	if (is_hybrid() || x86_pmu.extra_regs || x86_pmu.lbr_sel_map) {
 		cpuc->shared_regs = allocate_shared_regs(cpu);
 		if (!cpuc->shared_regs)
 			goto err;

arch/x86/events/perf_event.h

@@ -650,6 +650,7 @@ struct x86_hybrid_pmu {
 					[PERF_COUNT_HW_CACHE_RESULT_MAX];
 	struct event_constraint		*event_constraints;
 	struct event_constraint		*pebs_constraints;
+	struct extra_reg		*extra_regs;
 };
 
 static __always_inline struct x86_hybrid_pmu *hybrid_pmu(struct pmu *pmu)