From: Robert Richter <robert.richter@amd.com>
Date: Fri, 15 Jun 2012 17:06:44 +0000 (+0200)
Subject: perf/x86/amd: Fix RDPMC index calculation for AMD family 15h
X-Git-Tag: v3.12-rc1~2749^2~39
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=76958a61e42fb6277a8431eb17e4bdb24176f1b7;p=kernel%2Fkernel-generic.git

perf/x86/amd: Fix RDPMC index calculation for AMD family 15h

The RDPMC index calculation is wrong for AMD family 15h
(X86_FEATURE_ PERFCTR_CORE set). This leads to a #GP when
accessing the counter:

 Pid: 2237, comm: syslog-ng Not tainted 3.5.0-rc1-perf-x86_64-standard-g130ff90 #135 AMD Pike/Pike
 RIP: 0010:[<ffffffff8100dc33>]  [<ffffffff8100dc33>] x86_perf_event_update+0x27/0x66

While the msr address offset is (index << 1) we must use index to
select the correct rdpmc.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vince Weaver <vweaver1@eecs.utk.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 766c76d..d1f38c9 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -823,7 +823,7 @@ static inline void x86_assign_hw_event(struct perf_event *event,
 	} else {
 		hwc->config_base = x86_pmu_config_addr(hwc->idx);
 		hwc->event_base  = x86_pmu_event_addr(hwc->idx);
-		hwc->event_base_rdpmc = x86_pmu_addr_offset(hwc->idx);
+		hwc->event_base_rdpmc = hwc->idx;
 	}
 }