Commit-ID: 89666c50472263fba97b7edbfd2a642d1d9d6f74 Gitweb: http://git.kernel.org/tip/89666c50472263fba97b7edbfd2a642d1d9d6f74 Author: Sebastian Andrzej Siewior <[email protected]> AuthorDate: Thu, 17 Nov 2016 19:35:40 +0100 Committer: Thomas Gleixner <[email protected]> CommitDate: Tue, 22 Nov 2016 23:34:43 +0100
x86/oprofile/nmi: 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: Sebastian Andrzej Siewior <[email protected]> Cc: Robert Richter <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> --- arch/x86/oprofile/nmi_int.c | 61 +++++++++++++-------------------------------- 1 file changed, 18 insertions(+), 43 deletions(-) diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c index c39172c..ffdbc48 100644 --- a/arch/x86/oprofile/nmi_int.c +++ b/arch/x86/oprofile/nmi_int.c @@ -339,10 +339,11 @@ fail: return 0; } -static void nmi_cpu_setup(void *dummy) +static void nmi_cpu_setup(void) { int cpu = smp_processor_id(); struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu); + nmi_cpu_save_registers(msrs); raw_spin_lock(&oprofilefs_lock); model->setup_ctrs(model, msrs); @@ -369,7 +370,7 @@ static void nmi_cpu_restore_registers(struct op_msrs *msrs) } } -static void nmi_cpu_shutdown(void *dummy) +static void nmi_cpu_shutdown(void) { unsigned int v; int cpu = smp_processor_id(); @@ -387,24 +388,26 @@ static void nmi_cpu_shutdown(void *dummy) nmi_cpu_restore_registers(msrs); } -static void nmi_cpu_up(void) +static int nmi_cpu_online(unsigned int cpu) { local_irq_disable(); if (nmi_enabled) - nmi_cpu_setup(NULL); + nmi_cpu_setup(); if (ctr_running) nmi_cpu_start(NULL); local_irq_enable(); + return 0; } -static void nmi_cpu_down(void) +static int nmi_cpu_down_prep(unsigned int cpu) { local_irq_disable(); if (ctr_running) nmi_cpu_stop(NULL); if (nmi_enabled) - nmi_cpu_shutdown(NULL); + nmi_cpu_shutdown(); local_irq_enable(); + return 0; } static int nmi_create_files(struct dentry *root) @@ -437,24 +440,7 @@ static int nmi_create_files(struct dentry *root) return 0; } -static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action, - void *data) -{ - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_DOWN_FAILED: - case CPU_ONLINE: - nmi_cpu_up(); - break; - case CPU_DOWN_PREPARE: - nmi_cpu_down(); - break; - } - return NOTIFY_DONE; -} - -static struct notifier_block oprofile_cpu_nb = { - .notifier_call = oprofile_cpu_notifier -}; +static enum cpuhp_state cpuhp_nmi_online; static int nmi_setup(void) { @@ -497,20 +483,17 @@ static int nmi_setup(void) if (err) goto fail; - cpu_notifier_register_begin(); - - /* Use get/put_online_cpus() to protect 'nmi_enabled' */ - get_online_cpus(); nmi_enabled = 1; /* make nmi_enabled visible to the nmi handler: */ smp_mb(); - on_each_cpu(nmi_cpu_setup, NULL, 1); - __register_cpu_notifier(&oprofile_cpu_nb); - put_online_cpus(); - - cpu_notifier_register_done(); - + err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/oprofile:online", + nmi_cpu_online, nmi_cpu_down_prep); + if (err < 0) + goto fail_nmi; + cpuhp_nmi_online = err; return 0; +fail_nmi: + unregister_nmi_handler(NMI_LOCAL, "oprofile"); fail: free_msrs(); return err; @@ -520,17 +503,9 @@ static void nmi_shutdown(void) { struct op_msrs *msrs; - cpu_notifier_register_begin(); - - /* Use get/put_online_cpus() to protect 'nmi_enabled' & 'ctr_running' */ - get_online_cpus(); - on_each_cpu(nmi_cpu_shutdown, NULL, 1); + cpuhp_remove_state(cpuhp_nmi_online); nmi_enabled = 0; ctr_running = 0; - __unregister_cpu_notifier(&oprofile_cpu_nb); - put_online_cpus(); - - cpu_notifier_register_done(); /* make variables visible to the nmi handler: */ smp_mb();
