From 2dd887e32175b624375570a0361083eb2cd64a07 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 20 Nov 2015 15:02:44 +0000 Subject: xen/time: use READ_ONCE Use READ_ONCE through the code, rather than explicit barriers. Suggested-by: Mark Rutland Signed-off-by: Stefano Stabellini Signed-off-by: David Vrabel --- drivers/xen/time.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) (limited to 'drivers/xen/time.c') diff --git a/drivers/xen/time.c b/drivers/xen/time.c index 433fe247c5ff..71078425c9ea 100644 --- a/drivers/xen/time.c +++ b/drivers/xen/time.c @@ -25,7 +25,7 @@ static u64 get64(const u64 *p) if (BITS_PER_LONG < 64) { u32 *p32 = (u32 *)p; - u32 h, l; + u32 h, l, h2; /* * Read high then low, and then make sure high is @@ -34,15 +34,14 @@ static u64 get64(const u64 *p) * XXX some clean way to make this endian-proof? */ do { - h = p32[1]; - barrier(); - l = p32[0]; - barrier(); - } while (p32[1] != h); + h = READ_ONCE(p32[1]); + l = READ_ONCE(p32[0]); + h2 = READ_ONCE(p32[1]); + } while(h2 != h); ret = (((u64)h) << 32) | l; } else - ret = *p; + ret = READ_ONCE(*p); return ret; } @@ -66,9 +65,7 @@ void xen_get_runstate_snapshot(struct vcpu_runstate_info *res) */ do { state_time = get64(&state->state_entry_time); - barrier(); - *res = *state; - barrier(); + *res = READ_ONCE(*state); } while (get64(&state->state_entry_time) != state_time); } -- cgit v1.2.3