perf/x86/intel/lbr: Use correct index to save/restore LBR_INFO with call stack

Use the correct index to save/restore the LBR_INFO_x MSR in
callstack mode. This is more a cleanup, as even with the wrong
index the register was correctly saved/restored, and also
LBR callgraph mode in perf tools do not really need anything in
LBR_INFO. But still better to use the right index.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: eranian@google.com
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1432786398-23861-5-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/perf_event_intel_lbr.c

@@ -245,7 +245,7 @@ static void __intel_pmu_lbr_restore(struct x86_perf_task_context *task_ctx)
 		wrmsrl(x86_pmu.lbr_from + lbr_idx, task_ctx->lbr_from[i]);
 		wrmsrl(x86_pmu.lbr_to + lbr_idx, task_ctx->lbr_to[i]);
 		if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
-			wrmsrl(MSR_LBR_INFO_0 + i, task_ctx->lbr_info[i]);
+			wrmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
 	}
 	task_ctx->lbr_stack_state = LBR_NONE;
 }
@@ -268,7 +268,7 @@ static void __intel_pmu_lbr_save(struct x86_perf_task_context *task_ctx)
 		rdmsrl(x86_pmu.lbr_from + lbr_idx, task_ctx->lbr_from[i]);
 		rdmsrl(x86_pmu.lbr_to + lbr_idx, task_ctx->lbr_to[i]);
 		if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
-			rdmsrl(MSR_LBR_INFO_0 + i, task_ctx->lbr_info[i]);
+			rdmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
 	}
 	task_ctx->lbr_stack_state = LBR_VALID;
 }