[arm64] enable cycle counter

littlekernel · Sep 16, 2016 · 86f7743 · 86f7743
1 parent f2c9072
commit 86f7743
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 0 deletions.
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;

diff --git a/arch/arm64/mp.c b/arch/arm64/mp.c
@@ -81,6 +81,10 @@ enum handler_return arm_ipi_reschedule_handler(void *arg)
 
 void arch_mp_init_percpu(void)
 {
+    int pmcr_mask = 1;
+
+    __asm__ volatile("msr pmcr_el0, %0":: "r"(pmcr_mask):);
+
     register_int_handler(MP_IPI_GENERIC + GIC_IPI_BASE, &arm_ipi_generic_handler, 0);
     register_int_handler(MP_IPI_RESCHEDULE + GIC_IPI_BASE, &arm_ipi_reschedule_handler, 0);