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>

diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index 98ac573..e6131d4 100644 (file)
--- 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 6f91e94..569d057 100644 (file)
--- 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,