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authorMark Brown <broonie@kernel.org>2016-11-04 12:16:38 -0600
committerMark Brown <broonie@kernel.org>2016-11-04 12:16:38 -0600
commitcc9b94029e9ef51787af908e9856b1eed314bc00 (patch)
tree9675310b89d0f6fb1f7bd9423f0638c4ee5226fd /arch/x86/include/asm/pvclock.h
parent13bed58ce8748d430a26e353a09b89f9d613a71f (diff)
parent1b5b42216469b05ef4b5916cb40b127dfab1da88 (diff)
downloadtalos-op-linux-cc9b94029e9ef51787af908e9856b1eed314bc00.tar.gz
talos-op-linux-cc9b94029e9ef51787af908e9856b1eed314bc00.zip
Merge branch 'topic/error' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator into regulator-fixed
Diffstat (limited to 'arch/x86/include/asm/pvclock.h')
-rw-r--r--arch/x86/include/asm/pvclock.h47
1 files changed, 24 insertions, 23 deletions
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index fdcc04020636..3ad741b84072 100644
--- 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.
@@ -69,30 +87,13 @@ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
}
static __always_inline
-u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
+cycle_t __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
+ u64 tsc)
{
- u64 delta = rdtsc_ordered() - src->tsc_timestamp;
- return pvclock_scale_delta(delta, src->tsc_to_system_mul,
- src->tsc_shift);
-}
-
-static __always_inline
-unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
- cycle_t *cycles, u8 *flags)
-{
- unsigned version;
- cycle_t ret, offset;
- u8 ret_flags;
-
- version = src->version;
-
- offset = pvclock_get_nsec_offset(src);
- ret = src->system_time + offset;
- ret_flags = src->flags;
-
- *cycles = ret;
- *flags = ret_flags;
- return version;
+ u64 delta = tsc - 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 {
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