From 914fb85f01571233af199a78ed1f88d9268421fd Mon Sep 17 00:00:00 2001 From: Anna-Maria Gleixner Date: Sun, 27 Nov 2016 00:13:43 +0100 Subject: arm64/cpuinfo: Make hotplug notifier symmetric There is no requirement to keep the sysfs files around until the CPU is completely dead. Remove them during the DOWN_PREPARE notification. This is a preparatory patch for converting to the hotplug state machine. Signed-off-by: Anna-Maria Gleixner Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Suzuki K Poulose Cc: Catalin Marinas Cc: Will Deacon Cc: rt@linutronix.de Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20161126231350.10321-16-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- arch/arm64/kernel/cpuinfo.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm64') diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index b3d5b3e8fbcb..19aad7041e14 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -272,9 +272,10 @@ static int cpuid_callback(struct notifier_block *nb, switch (action & ~CPU_TASKS_FROZEN) { case CPU_ONLINE: + case CPU_DOWN_FAILED: rc = cpuid_add_regs(cpu); break; - case CPU_DEAD: + case CPU_DOWN_PREPARE: rc = cpuid_remove_regs(cpu); break; } -- cgit v1.2.3 From a7ce95e1741f2d866481c8138a84ce5af61eb219 Mon Sep 17 00:00:00 2001 From: Anna-Maria Gleixner Date: Sun, 27 Nov 2016 00:13:44 +0100 Subject: arm64/cpuinfo: 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: Anna-Maria Gleixner Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Suzuki K Poulose Cc: Catalin Marinas Cc: Will Deacon Cc: rt@linutronix.de Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20161126231350.10321-17-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- arch/arm64/kernel/cpuinfo.c | 37 +++++++++---------------------------- 1 file changed, 9 insertions(+), 28 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 19aad7041e14..7b7be71e87bf 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -227,7 +227,7 @@ static struct attribute_group cpuregs_attr_group = { .name = "identification" }; -static int cpuid_add_regs(int cpu) +static int cpuid_cpu_online(unsigned int cpu) { int rc; struct device *dev; @@ -248,7 +248,7 @@ out: return rc; } -static int cpuid_remove_regs(int cpu) +static int cpuid_cpu_offline(unsigned int cpu) { struct device *dev; struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu); @@ -264,41 +264,22 @@ static int cpuid_remove_regs(int cpu) return 0; } -static int cpuid_callback(struct notifier_block *nb, - unsigned long action, void *hcpu) -{ - int rc = 0; - unsigned long cpu = (unsigned long)hcpu; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_ONLINE: - case CPU_DOWN_FAILED: - rc = cpuid_add_regs(cpu); - break; - case CPU_DOWN_PREPARE: - rc = cpuid_remove_regs(cpu); - break; - } - - return notifier_from_errno(rc); -} - static int __init cpuinfo_regs_init(void) { - int cpu; - - cpu_notifier_register_begin(); + int cpu, ret; for_each_possible_cpu(cpu) { struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu); kobject_init(&info->kobj, &cpuregs_kobj_type); - if (cpu_online(cpu)) - cpuid_add_regs(cpu); } - __hotcpu_notifier(cpuid_callback, 0); - cpu_notifier_register_done(); + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online", + cpuid_cpu_online, cpuid_cpu_offline); + if (ret < 0) { + pr_err("cpuinfo: failed to register hotplug callbacks.\n"); + return ret; + } return 0; } static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info) -- cgit v1.2.3