x86: Add function to read time stamp counter
Put this function in the u-boot-x86.h header file. We could instead create
timer.h perhaps.
We support setting a base time, and reading the time relative to this base.
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/include/asm/u-boot-x86.h b/arch/x86/include/asm/u-boot-x86.h
index a4a5ae0..11be5c3 100644
--- a/arch/x86/include/asm/u-boot-x86.h
+++ b/arch/x86/include/asm/u-boot-x86.h
@@ -68,4 +68,16 @@
void board_init_f_r_trampoline(ulong) __attribute__ ((noreturn));
void board_init_f_r(void) __attribute__ ((noreturn));
+/* Read the time stamp counter */
+static inline uint64_t rdtsc(void)
+{
+ uint32_t high, low;
+ __asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high));
+ return (((uint64_t)high) << 32) | low;
+}
+
+/* board/... */
+void timer_set_tsc_base(uint64_t new_base);
+uint64_t timer_get_tsc(void);
+
#endif /* _U_BOOT_I386_H_ */