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perf/x86/amd/uncore: Convert to hotplug state machine
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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>
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Richard Cochran authored and Ingo Molnar committed Jul 14, 2016
1 parent 1a246b9 commit 96b2bd3
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Showing 2 changed files with 35 additions and 90 deletions.
122 changes: 32 additions & 90 deletions arch/x86/events/amd/uncore.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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,
Expand All @@ -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,
Expand Down Expand Up @@ -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)
Expand All @@ -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)
Expand Down Expand Up @@ -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);
Expand Down
3 changes: 3 additions & 0 deletions include/linux/cpuhotplug.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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,
Expand All @@ -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,
Expand Down

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