From 11cab711f686893f2696a061dfca30454a624784 Mon Sep 17 00:00:00 2001 From: Cliff Wickman Date: Fri, 22 Jun 2012 08:12:12 -0500 Subject: [PATCH] x86/uv: Fix the UV BAU destination timeout period Correct the calculation of a destination timeout period, which is used to distinguish between a destination timeout and the situation where all the target software ack resources are full and a request is returned immediately. The problem is that integer arithmetic was overflowing, yielding a very large result. Without this fix destination timeouts are identified as resource 'plugged' events and an ipi method of resource releasing is unnecessarily employed. Signed-off-by: Cliff Wickman Link: http://lkml.kernel.org/r/20120622131212.GA31884@sgi.com Signed-off-by: Ingo Molnar --- arch/x86/platform/uv/tlb_uv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c index 59880afa851f..0c48d438cbba 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -1811,8 +1811,8 @@ static int calculate_destination_timeout(void) index = (mmr_image >> BAU_URGENCY_7_SHIFT) & BAU_URGENCY_7_MASK; mmr_image = uv_read_local_mmr(UVH_TRANSACTION_TIMEOUT); mult2 = (mmr_image >> BAU_TRANS_SHIFT) & BAU_TRANS_MASK; - base = timeout_base_ns[index]; - ts_ns = base * mult1 * mult2; + ts_ns = timeout_base_ns[index]; + ts_ns *= (mult1 * mult2); ret = ts_ns / 1000; } else { /* 4 bits 0/1 for 10/80us base, 3 bits of multiplier */ -- 2.20.1