Merge remote-tracking branch 'mkp-scsi/4.8/scsi-fixes' into fixes

[cascardo/linux.git] / arch / x86 / include / asm / pvclock.h

diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index 7c1c895..d019f0c 100644 (file)
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -25,6 +25,24 @@ void pvclock_resume(void);
 
 void pvclock_touch_watchdogs(void);
 
+static __always_inline
+unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src)
+{
+       unsigned version = src->version & ~1;
+       /* Make sure that the version is read before the data. */
+       virt_rmb();
+       return version;
+}
+
+static __always_inline
+bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src,
+                       unsigned version)
+{
+       /* Make sure that the version is re-read after the data. */
+       virt_rmb();
+       return unlikely(version != src->version);
+}
+
 /*
  * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
  * yielding a 64-bit result.
@@ -69,23 +87,12 @@ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
 }
 
 static __always_inline
-unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
-                              cycle_t *cycles, u8 *flags)
+cycle_t __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src)
 {
-       unsigned version;
-       cycle_t offset;
-       u64 delta;
-
-       version = src->version;
-       /* Make the latest version visible */
-       smp_rmb();
-
-       delta = rdtsc_ordered() - src->tsc_timestamp;
-       offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
-                                  src->tsc_shift);
-       *cycles = src->system_time + offset;
-       *flags = src->flags;
-       return version;
+       u64 delta = rdtsc_ordered() - src->tsc_timestamp;
+       cycle_t offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
+                                            src->tsc_shift);
+       return src->system_time + offset;
 }
 
 struct pvclock_vsyscall_time_info {