kern/perfmon.c: Add pmc id to index map.

Will be used to handle calls from the pmu implementations.

1 files changed, 21 insertions, 10 deletions

diff --git a/kern/perfmon.c b/kern/perfmon.c
index d42fd09..5627726 100644
--- a/kern/perfmon.c
+++ b/kern/perfmon.c
@@ -183,6 +183,8 @@ struct perfmon_cpu_pmu {
 static struct perfmon_pmu_ops pmu_driver __read_mostly;
 
 static struct perfmon_pmu perfmon_pmu;
+static unsigned int perfmon_pmc_id_to_index[PERFMON_MAX_PMCS];
+
 static struct perfmon_cpu_pmu perfmon_cpu_pmu __percpu;
 
 /*
@@ -264,6 +266,16 @@ perfmon_pmc_lookup(unsigned int raw_event_id)
     return NULL;
 }
 
+static inline unsigned int
+perfmon_pmc_index(const struct perfmon_pmc *pmc)
+{
+    unsigned int index;
+
+    index = pmc - perfmon_pmu.pmcs;
+    assert(index < ARRAY_SIZE(perfmon_pmu.pmcs));
+    return index;
+}
+
 /*
  * Obtain a reference on a PMC for the given event.
  *
@@ -274,6 +286,7 @@ perfmon_pmc_get(struct perfmon_pmc **pmcp, const struct perfmon_event *event)
 {
     struct perfmon_pmc *pmc;
     unsigned int raw_event_id;
+    unsigned int pmc_index;
     int error;
 
     error = perfmon_translate(&raw_event_id, event->type, event->id);
@@ -292,6 +305,9 @@ perfmon_pmc_get(struct perfmon_pmc **pmcp, const struct perfmon_event *event)
         if (error) {
             goto out;
         }
+        pmc_index = perfmon_pmc_index(pmc);
+        assert(perfmon_pmc_id_to_index[pmc->id] == UINT32_MAX);
+        perfmon_pmc_id_to_index[pmc->id] = pmc_index;
     }
 
     pmc->nr_refs++;
@@ -320,21 +336,13 @@ perfmon_pmc_put(struct perfmon_pmc *pmc)
 
     if (pmc->nr_refs == 0) {
         pmu_driver.free(pmc->id);
+        assert(perfmon_pmc_id_to_index[pmc->id] != UINT32_MAX);
+        perfmon_pmc_id_to_index[pmc->id] = UINT32_MAX;
     }
 
     spinlock_unlock(&perfmon_pmu.lock);
 }
 
-static inline unsigned int
-perfmon_pmc_index(const struct perfmon_pmc *pmc)
-{
-    unsigned int index;
-
-    index = pmc - perfmon_pmu.pmcs;
-    assert(index < ARRAY_SIZE(perfmon_pmu.pmcs));
-    return index;
-}
-
 static inline struct perfmon_pmc *
 perfmon_pmc_from_index(unsigned int index)
 {
@@ -451,6 +459,9 @@ perfmon_setup(void)
     for (i = 0; i < ARRAY_SIZE(perfmon_pmu.pmcs); i++) {
         perfmon_pmu.pmcs[i].nr_refs = 0;
     }
+    for (i = 0; i < ARRAY_SIZE(perfmon_pmc_id_to_index); i++) {
+        perfmon_pmc_id_to_index[i] = UINT32_MAX;
+    }
 
     for (i = 0; i < cpu_count(); i++) {
         perfmon_cpu_pmu_init(percpu_ptr(perfmon_cpu_pmu, i));