[arm64] enable cycle counter

littlekernel · Sep 1, 2016 · 5946efc · 5946efc
1 parent f2c9072
commit 5946efc
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diff --git a/arch/arm64/arch.c b/arch/arm64/arch.c
@@ -63,6 +63,10 @@ void arch_early_init(void)
 
 void arch_init(void)
 {
+
+    int pmcr_mask = 1;
+
+    __asm__ volatile("msr pmcr_el0, %0":: "r"(pmcr_mask):);
 #if WITH_SMP
     arch_mp_init_percpu();
 

diff --git a/arch/arm64/include/arch/arch_ops.h b/arch/arm64/include/arch/arch_ops.h
@@ -233,6 +233,14 @@ static inline uint32_t arch_cycle_count(void)
                      : "=r" (count)
                     );
     return count;
+#elif ARM_ISA_ARMV8
+    uint32_t count;
+
+    ISB;
+    __asm__ volatile("mrs %0, pmccntr_el0"
+                     : "=r" (count)
+                    );
+    return count;
 #else
 //#warning no arch_cycle_count implementation
     return 0;