linux-kernel - [PATCH v7 03/10] perf/x86/rapl: Remove the cpu_to_rapl

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Message-ID: <20241115060805.447565-4-Dhananjay.Ugwekar@amd.com>
Date: Fri, 15 Nov 2024 06:07:59 +0000
From: Dhananjay Ugwekar <Dhananjay.Ugwekar@....com>
To: <peterz@...radead.org>, <mingo@...hat.com>, <rui.zhang@...el.com>,
	<irogers@...gle.com>, <kan.liang@...ux.intel.com>, <tglx@...utronix.de>,
	<bp@...en8.dei>, <gautham.shenoy@....com>
CC: <kprateek.nayak@....com>, <ravi.bangoria@....com>, <x86@...nel.org>,
	<linux-perf-users@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	"Dhananjay Ugwekar" <Dhananjay.Ugwekar@....com>
Subject: [PATCH v7 03/10] perf/x86/rapl: Remove the cpu_to_rapl_pmu() function

Prepare for the addition of RAPL core energy counter support.
Post which, one CPU might be mapped to more than one rapl_pmu
(package/die one and a core one). So, remove the cpu_to_rapl_pmu()
function.

Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@....com>
Reviewed-by: Zhang Rui <rui.zhang@...el.com>
Tested-by: Zhang Rui <rui.zhang@...el.com>
---
v7 changes:
* Add comment to get_rapl_pmu_idx()
* Change the rapl_pmu_idx variable in rapl_pmu_event_init() to 
  unsigned int
---
 arch/x86/events/rapl.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
index f70c49ca0ef3..a3c063176513 100644
--- a/arch/x86/events/rapl.c
+++ b/arch/x86/events/rapl.c
@@ -157,22 +157,15 @@ static struct perf_msr *rapl_msrs;
  * RAPL PMU scope.
  */
 static inline unsigned int get_rapl_pmu_idx(int cpu)
-{
+{	/*
+	 * Returns unsigned int, which converts the '-1' return value
+	 * (for non-existent mappings in topology map) to UINT_MAX, so
+	 * the error check in the caller is simplified.
+	 */
 	return rapl_pmu_is_pkg_scope() ? topology_logical_package_id(cpu) :
 					 topology_logical_die_id(cpu);
 }
 
-static inline struct rapl_pmu *cpu_to_rapl_pmu(unsigned int cpu)
-{
-	unsigned int rapl_pmu_idx = get_rapl_pmu_idx(cpu);
-
-	/*
-	 * The unsigned check also catches the '-1' return value for non
-	 * existent mappings in the topology map.
-	 */
-	return rapl_pmu_idx < rapl_pmus->nr_rapl_pmu ? rapl_pmus->pmus[rapl_pmu_idx] : NULL;
-}
-
 static inline u64 rapl_read_counter(struct perf_event *event)
 {
 	u64 raw;
@@ -350,6 +343,7 @@ static int rapl_pmu_event_init(struct perf_event *event)
 	u64 cfg = event->attr.config & RAPL_EVENT_MASK;
 	int bit, ret = 0;
 	struct rapl_pmu *pmu;
+	unsigned int rapl_pmu_idx;
 
 	/* only look at RAPL events */
 	if (event->attr.type != rapl_pmus->pmu.type)
@@ -376,8 +370,12 @@ static int rapl_pmu_event_init(struct perf_event *event)
 	if (event->attr.sample_period) /* no sampling */
 		return -EINVAL;
 
+	rapl_pmu_idx = get_rapl_pmu_idx(event->cpu);
+	if (rapl_pmu_idx >= rapl_pmus->nr_rapl_pmu)
+		return -EINVAL;
+
 	/* must be done before validate_group */
-	pmu = cpu_to_rapl_pmu(event->cpu);
+	pmu = rapl_pmus->pmus[rapl_pmu_idx];
 	if (!pmu)
 		return -EINVAL;
 	event->pmu_private = pmu;
-- 
2.34.1