perf/x86/amd/uncore: Use dynamic events array

If AMD Performance Monitoring Version 2 (PerfMonV2) is
supported, the number of available counters for a given
uncore PMU may not be fixed across families and models
and has to be determined at runtime.

The per-cpu uncore PMU data currently uses a fixed-sized
array for event information. Make it dynamic based on the
number of available counters.

Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/21eea0cb6de9d14f78d52d1d62637ae02bc900f5.1652954372.git.sandipan.das@amd.com

diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index 0d04414b97d2d498cc3c6bb928be5072f4724777..8dfcf93711ab09bdbe8f8583570b12f6ccfeb9c3 100644 (file)
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -21,7 +21,6 @@
 #define NUM_COUNTERS_NB                4
 #define NUM_COUNTERS_L2                4
 #define NUM_COUNTERS_L3                6
-#define MAX_COUNTERS           6
 
 #define RDPMC_BASE_NB          6
 #define RDPMC_BASE_LLC         10
@@ -46,7 +45,7 @@ struct amd_uncore {
        u32 msr_base;
        cpumask_t *active_mask;
        struct pmu *pmu;
-       struct perf_event *events[MAX_COUNTERS];
+       struct perf_event **events;
        struct hlist_node node;
 };
 
@@ -370,11 +369,19 @@ static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
                        cpu_to_node(cpu));
 }
 
+static inline struct perf_event **
+amd_uncore_events_alloc(unsigned int num, unsigned int cpu)
+{
+       return kzalloc_node(sizeof(struct perf_event *) * num, GFP_KERNEL,
+                           cpu_to_node(cpu));
+}
+
 static int amd_uncore_cpu_up_prepare(unsigned int cpu)
 {
-       struct amd_uncore *uncore_nb = NULL, *uncore_llc;
+       struct amd_uncore *uncore_nb = NULL, *uncore_llc = NULL;
 
        if (amd_uncore_nb) {
+               *per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
                uncore_nb = amd_uncore_alloc(cpu);
                if (!uncore_nb)
                        goto fail;
@@ -384,11 +391,15 @@ static int amd_uncore_cpu_up_prepare(unsigned int cpu)
                uncore_nb->msr_base = MSR_F15H_NB_PERF_CTL;
                uncore_nb->active_mask = &amd_nb_active_mask;
                uncore_nb->pmu = &amd_nb_pmu;
+               uncore_nb->events = amd_uncore_events_alloc(num_counters_nb, cpu);
+               if (!uncore_nb->events)
+                       goto fail;
                uncore_nb->id = -1;
                *per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb;
        }
 
        if (amd_uncore_llc) {
+               *per_cpu_ptr(amd_uncore_llc, cpu) = NULL;
                uncore_llc = amd_uncore_alloc(cpu);
                if (!uncore_llc)
                        goto fail;
@@ -398,6 +409,9 @@ static int amd_uncore_cpu_up_prepare(unsigned int cpu)
                uncore_llc->msr_base = MSR_F16H_L2I_PERF_CTL;
                uncore_llc->active_mask = &amd_llc_active_mask;
                uncore_llc->pmu = &amd_llc_pmu;
+               uncore_llc->events = amd_uncore_events_alloc(num_counters_llc, cpu);
+               if (!uncore_llc->events)
+                       goto fail;
                uncore_llc->id = -1;
                *per_cpu_ptr(amd_uncore_llc, cpu) = uncore_llc;
        }
@@ -405,9 +419,16 @@ static int amd_uncore_cpu_up_prepare(unsigned int cpu)
        return 0;
 
 fail:
-       if (amd_uncore_nb)
-               *per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
-       kfree(uncore_nb);
+       if (uncore_nb) {
+               kfree(uncore_nb->events);
+               kfree(uncore_nb);
+       }
+
+       if (uncore_llc) {
+               kfree(uncore_llc->events);
+               kfree(uncore_llc);
+       }
+
        return -ENOMEM;
 }
 
@@ -540,8 +561,11 @@ static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
        if (cpu == uncore->cpu)
                cpumask_clear_cpu(cpu, uncore->active_mask);
 
-       if (!--uncore->refcnt)
+       if (!--uncore->refcnt) {
+               kfree(uncore->events);
                kfree(uncore);
+       }
+
        *per_cpu_ptr(uncores, cpu) = NULL;
 }