linux-kernel - [PATCH 2/4] perf, amd: Refactor northbridge event constraints handler for code sharing

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Date:	Fri, 9 Nov 2012 19:01:36 -0600
From:	Jacob Shin <jacob.shin@....com>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
CC:	Paul Mackerras <paulus@...ba.org>, Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	Stephane Eranian <eranian@...gle.com>,
	Robert Richter <rric@...nel.org>, <x86@...nel.org>,
	<linux-kernel@...r.kernel.org>, Jacob Shin <jacob.shin@....com>
Subject: [PATCH 2/4] perf, amd: Refactor northbridge event constraints handler for code sharing

Breakout and generalize family 10h northbridge event contraints code
so that later we can reuse the same code path with other AMD processor
families that have the same northbridge event constraints.

Based on previous patch by Robert Richter <rric@...nel.org>

Signed-off-by: Jacob Shin <jacob.shin@....com>
Signed-off-by: Robert Richter <rric@...nel.org>
---
 arch/x86/kernel/cpu/perf_event_amd.c |   43 ++++++++++++++++++++--------------
 1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index d60c5c7..d17debd 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -188,20 +188,13 @@ static inline int amd_has_nb(struct cpu_hw_events *cpuc)
 	return nb && nb->nb_id != -1;
 }
 
-static void amd_put_event_constraints(struct cpu_hw_events *cpuc,
-				      struct perf_event *event)
+static void __amd_put_nb_event_constraints(struct cpu_hw_events *cpuc,
+					   struct perf_event *event)
 {
-	struct hw_perf_event *hwc = &event->hw;
 	struct amd_nb *nb = cpuc->amd_nb;
 	int i;
 
 	/*
-	 * only care about NB events
-	 */
-	if (!(amd_has_nb(cpuc) && amd_is_nb_event(hwc)))
-		return;
-
-	/*
 	 * need to scan whole list because event may not have
 	 * been assigned during scheduling
 	 *
@@ -247,12 +240,13 @@ static void amd_put_event_constraints(struct cpu_hw_events *cpuc,
   *
   * Given that resources are allocated (cmpxchg), they must be
   * eventually freed for others to use. This is accomplished by
-  * calling amd_put_event_constraints().
+  * calling __amd_put_nb_event_constraints()
   *
   * Non NB events are not impacted by this restriction.
   */
 static struct event_constraint *
-amd_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
+__amd_get_nb_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event,
+			       struct event_constraint *c)
 {
 	struct hw_perf_event *hwc = &event->hw;
 	struct amd_nb *nb = cpuc->amd_nb;
@@ -260,12 +254,6 @@ amd_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
 	int idx, new = -1;
 
 	/*
-	 * if not NB event or no NB, then no constraints
-	 */
-	if (!(amd_has_nb(cpuc) && amd_is_nb_event(hwc)))
-		return &unconstrained;
-
-	/*
 	 * detect if already present, if so reuse
 	 *
 	 * cannot merge with actual allocation
@@ -275,7 +263,7 @@ amd_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
 	 * because of successive calls to x86_schedule_events() from
 	 * hw_perf_group_sched_in() without hw_perf_enable()
 	 */
-	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
+	for_each_set_bit(idx, c->idxmsk, X86_PMC_IDX_MAX) {
 		if (new == -1 || hwc->idx == idx)
 			/* assign free slot, prefer hwc->idx */
 			old = cmpxchg(nb->owners + idx, NULL, event);
@@ -391,6 +379,25 @@ static void amd_pmu_cpu_dead(int cpu)
 	}
 }
 
+static struct event_constraint *
+amd_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
+{
+	/*
+	 * if not NB event or no NB, then no constraints
+	 */
+	if ((amd_has_nb(cpuc) && amd_is_nb_event(&event->hw)))
+		return &unconstrained;
+
+	return __amd_get_nb_event_constraints(cpuc, event, &unconstrained);
+}
+
+static void amd_put_event_constraints(struct cpu_hw_events *cpuc,
+				      struct perf_event *event)
+{
+	if (amd_has_nb(cpuc) && amd_is_nb_event(&event->hw))
+		__amd_put_nb_event_constraints(cpuc, event);
+}
+
 PMU_FORMAT_ATTR(event,	"config:0-7,32-35");
 PMU_FORMAT_ATTR(umask,	"config:8-15"	);
 PMU_FORMAT_ATTR(edge,	"config:18"	);
-- 
1.7.9.5


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