linux-kernel - [PATCH v12 02/16] perf/x86/lbr: Simplify the exposure check for the LBR

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Date:   Tue, 17 May 2022 11:40:46 -0400
From:   Yang Weijiang <weijiang.yang@...el.com>
To:     pbonzini@...hat.com, jmattson@...gle.com, seanjc@...gle.com,
        like.xu.linux@...il.com, vkuznets@...hat.com,
        kan.liang@...ux.intel.com, wei.w.wang@...el.com,
        kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Like Xu <like.xu@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Andi Kleen <ak@...ux.intel.com>,
        Yang Weijiang <weijiang.yang@...el.com>
Subject: [PATCH v12 02/16] perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers

From: Like Xu <like.xu@...ux.intel.com>

The x86_pmu.lbr_info is 0 unless explicitly initialized, so there's
no point checking x86_pmu.intel_cap.lbr_format.

Cc: Peter Zijlstra <peterz@...radead.org>
Reviewed-by: Kan Liang <kan.liang@...ux.intel.com>
Reviewed-by: Andi Kleen <ak@...ux.intel.com>
Signed-off-by: Like Xu <like.xu@...ux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@...el.com>
---
 arch/x86/events/intel/lbr.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index fe1742c4ca49..4529ce448b2e 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -1874,12 +1874,10 @@ void __init intel_pmu_arch_lbr_init(void)
  */
 int x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
 {
-	int lbr_fmt = x86_pmu.intel_cap.lbr_format;
-
 	lbr->nr = x86_pmu.lbr_nr;
 	lbr->from = x86_pmu.lbr_from;
 	lbr->to = x86_pmu.lbr_to;
-	lbr->info = (lbr_fmt == LBR_FORMAT_INFO) ? x86_pmu.lbr_info : 0;
+	lbr->info = x86_pmu.lbr_info;
 
 	return 0;
 }
-- 
2.27.0