From 96b2bd3866a0b045330e420a2f1829ff2a3399bc Mon Sep 17 00:00:00 2001
From: Richard Cochran <rcochran@linutronix.de>
Date: Wed, 13 Jul 2016 17:16:13 +0000
Subject: [PATCH] perf/x86/amd/uncore: Convert to hotplug state machine
Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153333.839150380@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/events/amd/uncore.c | 122 +++++++++--------------------------
include/linux/cpuhotplug.h | 3 +
2 files changed, 35 insertions(+), 90 deletions(-)
diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index 98ac57381bf9..e6131d4454e6 100644
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -358,7 +358,7 @@ amd_uncore_find_online_sibling(struct amd_uncore *this,
return this;
}
-static void amd_uncore_cpu_starting(unsigned int cpu)
+static int amd_uncore_cpu_starting(unsigned int cpu)
{
unsigned int eax, ebx, ecx, edx;
struct amd_uncore *uncore;
@@ -384,6 +384,8 @@ static void amd_uncore_cpu_starting(unsigned int cpu)
uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_l2);
*per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
}
+
+ return 0;
}
static void uncore_online(unsigned int cpu,
@@ -398,13 +400,15 @@ static void uncore_online(unsigned int cpu,
cpumask_set_cpu(cpu, uncore->active_mask);
}
-static void amd_uncore_cpu_online(unsigned int cpu)
+static int amd_uncore_cpu_online(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_online(cpu, amd_uncore_nb);
if (amd_uncore_l2)
uncore_online(cpu, amd_uncore_l2);
+
+ return 0;
}
static void uncore_down_prepare(unsigned int cpu,
@@ -433,13 +437,15 @@ static void uncore_down_prepare(unsigned int cpu,
}
}
-static void amd_uncore_cpu_down_prepare(unsigned int cpu)
+static int amd_uncore_cpu_down_prepare(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_down_prepare(cpu, amd_uncore_nb);
if (amd_uncore_l2)
uncore_down_prepare(cpu, amd_uncore_l2);
+
+ return 0;
}
static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
@@ -454,74 +460,19 @@ static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
*per_cpu_ptr(uncores, cpu) = NULL;
}
-static void amd_uncore_cpu_dead(unsigned int cpu)
+static int amd_uncore_cpu_dead(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_dead(cpu, amd_uncore_nb);
if (amd_uncore_l2)
uncore_dead(cpu, amd_uncore_l2);
-}
-
-static int
-amd_uncore_cpu_notifier(struct notifier_block *self, unsigned long action,
- void *hcpu)
-{
- unsigned int cpu = (long)hcpu;
-
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_UP_PREPARE:
- if (amd_uncore_cpu_up_prepare(cpu))
- return notifier_from_errno(-ENOMEM);
- break;
-
- case CPU_STARTING:
- amd_uncore_cpu_starting(cpu);
- break;
-
- case CPU_ONLINE:
- amd_uncore_cpu_online(cpu);
- break;
-
- case CPU_DOWN_PREPARE:
- amd_uncore_cpu_down_prepare(cpu);
- break;
-
- case CPU_UP_CANCELED:
- case CPU_DEAD:
- amd_uncore_cpu_dead(cpu);
- break;
-
- default:
- break;
- }
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block amd_uncore_cpu_notifier_block = {
- .notifier_call = amd_uncore_cpu_notifier,
- .priority = CPU_PRI_PERF + 1,
-};
-
-static void __init init_cpu_already_online(void *dummy)
-{
- unsigned int cpu = smp_processor_id();
-
- amd_uncore_cpu_starting(cpu);
- amd_uncore_cpu_online(cpu);
-}
-static void cleanup_cpu_online(void *dummy)
-{
- unsigned int cpu = smp_processor_id();
-
- amd_uncore_cpu_dead(cpu);
+ return 0;
}
static int __init amd_uncore_init(void)
{
- unsigned int cpu, cpu2;
int ret = -ENODEV;
if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
@@ -558,38 +509,29 @@ static int __init amd_uncore_init(void)
ret = 0;
}
- if (ret)
- goto fail_nodev;
-
- cpu_notifier_register_begin();
-
- /* init cpus already online before registering for hotplug notifier */
- for_each_online_cpu(cpu) {
- ret = amd_uncore_cpu_up_prepare(cpu);
- if (ret)
- goto fail_online;
- smp_call_function_single(cpu, init_cpu_already_online, NULL, 1);
- }
-
- __register_cpu_notifier(&amd_uncore_cpu_notifier_block);
- cpu_notifier_register_done();
-
+ /*
+ * Install callbacks. Core will call them for each online cpu.
+ */
+ if (cpuhp_setup_state(CPUHP_PERF_X86_AMD_UNCORE_PREP,
+ "PERF_X86_AMD_UNCORE_PREP",
+ amd_uncore_cpu_up_prepare, amd_uncore_cpu_dead))
+ goto fail_l2;
+
+ if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
+ "AP_PERF_X86_AMD_UNCORE_STARTING",
+ amd_uncore_cpu_starting, NULL))
+ goto fail_prep;
+ if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
+ "AP_PERF_X86_AMD_UNCORE_ONLINE",
+ amd_uncore_cpu_online,
+ amd_uncore_cpu_down_prepare))
+ goto fail_start;
return 0;
-
-fail_online:
- for_each_online_cpu(cpu2) {
- if (cpu2 == cpu)
- break;
- smp_call_function_single(cpu, cleanup_cpu_online, NULL, 1);
- }
- cpu_notifier_register_done();
-
- /* amd_uncore_nb/l2 should have been freed by cleanup_cpu_online */
- amd_uncore_nb = amd_uncore_l2 = NULL;
-
- if (boot_cpu_has(X86_FEATURE_PERFCTR_L2))
- perf_pmu_unregister(&amd_l2_pmu);
+fail_start:
+ cpuhp_remove_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING);
+fail_prep:
+ cpuhp_remove_state(CPUHP_PERF_X86_AMD_UNCORE_PREP);
fail_l2:
if (boot_cpu_has(X86_FEATURE_PERFCTR_NB))
perf_pmu_unregister(&amd_nb_pmu);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 6f91e94c9cc9..569d057cc7d5 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -7,6 +7,7 @@ enum cpuhp_state {
CPUHP_PERF_PREPARE,
CPUHP_PERF_X86_PREPARE,
CPUHP_PERF_X86_UNCORE_PREP,
+ CPUHP_PERF_X86_AMD_UNCORE_PREP,
CPUHP_NOTIFY_PREPARE,
CPUHP_BRINGUP_CPU,
CPUHP_AP_IDLE_DEAD,
@@ -20,6 +21,7 @@ enum cpuhp_state {
CPUHP_AP_IRQ_BCM2836_STARTING,
CPUHP_AP_ARM_MVEBU_COHERENCY,
CPUHP_AP_PERF_X86_UNCORE_STARTING,
+ CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
CPUHP_AP_PERF_X86_STARTING,
CPUHP_AP_NOTIFY_STARTING,
CPUHP_AP_ONLINE,
@@ -30,6 +32,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_ONLINE,
CPUHP_AP_PERF_X86_ONLINE,
CPUHP_AP_PERF_X86_UNCORE_ONLINE,
+ CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
CPUHP_AP_NOTIFY_ONLINE,
CPUHP_AP_ONLINE_DYN,
CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
--
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