xnu-7195.81.3.tar.gz

[apple/xnu.git] / libsyscall / wrappers / mach_continuous_time.c

diff --git a/libsyscall/wrappers/mach_continuous_time.c b/libsyscall/wrappers/mach_continuous_time.c
index 353ef0d87d9cef4f548c937fae0b93c47eb1cd75..e07aba3bf8cb174445f54cc4868bc858e2b36ce0 100644 (file)
--- a/libsyscall/wrappers/mach_continuous_time.c
+++ b/libsyscall/wrappers/mach_continuous_time.c
@@ -59,11 +59,12 @@ kern_return_t
 _mach_continuous_hwclock(uint64_t *cont_time __unused)
 {
 #if defined(__arm64__)
+#define ISB_SY          0xf
        uint8_t cont_hwclock = *((uint8_t*)_COMM_PAGE_CONT_HWCLOCK);
-       uint64_t timebase;
        if (cont_hwclock) {
-               __asm__ volatile ("isb\n" "mrs %0, CNTPCT_EL0" : "=r"(timebase));
-               *cont_time = timebase;
+               volatile uint64_t *base_ptr = (volatile uint64_t*)_COMM_PAGE_CONT_HW_TIMEBASE;
+               __builtin_arm_isb(ISB_SY);
+               *cont_time = __builtin_arm_rsr64("CNTVCT_EL0") + *base_ptr;
                return KERN_SUCCESS;
        }
 #endif