x86: introduce native_read_tscp
Targetting paravirt, this patch introduces native_read_tscp, in
place of rdtscp() macro. When in a paravirt guest, this will
involve a function call, and thus, cannot be done in the vdso area.
These users then have to call the native version directly
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/msr.h b/include/asm-x86/msr.h
index 0648b2d..b6262e9 100644
--- a/include/asm-x86/msr.h
+++ b/include/asm-x86/msr.h
@@ -7,6 +7,27 @@
# include <linux/types.h>
#endif
+#ifdef __KERNEL__
+#ifndef __ASSEMBLY__
+static inline unsigned long long native_read_tscp(int *aux)
+{
+ unsigned long low, high;
+ asm volatile (".byte 0x0f,0x01,0xf9"
+ : "=a" (low), "=d" (high), "=c" (*aux));
+ return low | ((u64)high >> 32);
+}
+
+#define rdtscp(low, high, aux) \
+ do { \
+ unsigned long long _val = native_read_tscp(&(aux)); \
+ (low) = (u32)_val; \
+ (high) = (u32)(_val >> 32); \
+ } while (0)
+
+#define rdtscpll(val, aux) (val) = native_read_tscp(&(aux))
+#endif
+#endif
+
#ifdef __i386__
#ifdef __KERNEL__
@@ -178,8 +199,6 @@
#define rdtscl(low) \
__asm__ __volatile__ ("rdtsc" : "=a" (low) : : "edx")
-#define rdtscp(low,high,aux) \
- __asm__ __volatile__ (".byte 0x0f,0x01,0xf9" : "=a" (low), "=d" (high), "=c" (aux))
#define rdtscll(val) do { \
unsigned int __a,__d; \
@@ -187,12 +206,6 @@
(val) = ((unsigned long)__a) | (((unsigned long)__d)<<32); \
} while(0)
-#define rdtscpll(val, aux) do { \
- unsigned long __a, __d; \
- __asm__ __volatile__ (".byte 0x0f,0x01,0xf9" : "=a" (__a), "=d" (__d), "=c" (aux)); \
- (val) = (__d << 32) | __a; \
-} while (0)
-
#define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
#define write_rdtscp_aux(val) wrmsr(0xc0000103, val, 0)