ARM: 7448/1: perf: remove arm_perf_pmu_ids global enumeration

In order to provide PMU name strings compatible with the OProfile
user ABI, an enumeration of all PMUs is currently used by perf to
identify each PMU uniquely. Unfortunately, this does not scale well
in the presence of multiple PMUs and creates a single, global namespace
across all PMUs in the system.

This patch removes the enumeration and instead uses the name string
for the PMU to map onto the OProfile variant. perf_pmu_name is
implemented for CPU PMUs, which is all that OProfile cares about anyway.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 6 insertions, 9 deletions

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 186c8cb982c5..df85eda3add3 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -47,17 +47,14 @@ static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
 /* Set at runtime when we know what CPU type we are. */
 static struct arm_pmu *cpu_pmu;
 
-enum arm_perf_pmu_ids
-armpmu_get_pmu_id(void)
+const char *perf_pmu_name(void)
 {
-        int id = -ENODEV;
-
-        if (cpu_pmu != NULL)
-                id = cpu_pmu->id;
+        if (!cpu_pmu)
+                return NULL;
 
-        return id;
+        return cpu_pmu->pmu.name;
 }
-EXPORT_SYMBOL_GPL(armpmu_get_pmu_id);
+EXPORT_SYMBOL_GPL(perf_pmu_name);
 
 int perf_num_counters(void)
 {
@@ -760,7 +757,7 @@ init_hw_perf_events(void)
                         cpu_pmu->name, cpu_pmu->num_events);
                 cpu_pmu_init(cpu_pmu);
                 register_cpu_notifier(&pmu_cpu_notifier);
-                armpmu_register(cpu_pmu, "cpu", PERF_TYPE_RAW);
+                armpmu_register(cpu_pmu, cpu_pmu->name, PERF_TYPE_RAW);
         } else {
                 pr_info("no hardware support available\n");
         }