From f92b5462a2f22d13a75dc663f7b2fac16a3e61cb Mon Sep 17 00:00:00 2001 From: James Morse Date: Mon, 8 Jan 2018 15:38:14 +0000 Subject: [PATCH] firmware: arm_sdei: add support for CPU private events Private SDE events are per-cpu, and need to be registered and enabled on each CPU. Hide this detail from the caller by adapting our {,un}register and {en,dis}able calls to send an IPI to each CPU if the event is private. CPU private events are unregistered when the CPU is powered-off, and re-registered when the CPU is brought back online. This saves bringing secondary cores back online to call private_reset() on shutdown, kexec and resume from hibernate. Signed-off-by: James Morse Signed-off-by: Catalin Marinas --- drivers/firmware/arm_sdei.c | 206 +++++++++++++++++++++++++++++++++--- 1 file changed, 193 insertions(+), 13 deletions(-) diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index c503bc5222ed..0c735363f54d 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -5,9 +5,11 @@ #include #include #include +#include #include #include #include +#include #include #include #include @@ -52,7 +54,13 @@ struct sdei_event { u8 priority; /* This pointer is handed to firmware as the event argument. */ - struct sdei_registered_event *registered; + union { + /* Shared events */ + struct sdei_registered_event *registered; + + /* CPU private events */ + struct sdei_registered_event __percpu *private_registered; + }; }; /* Take the mutex for any API call or modification. Take the mutex first. */ @@ -62,6 +70,34 @@ static DEFINE_MUTEX(sdei_events_lock); static DEFINE_SPINLOCK(sdei_list_lock); static LIST_HEAD(sdei_list); +/* Private events are registered/enabled via IPI passing one of these */ +struct sdei_crosscall_args { + struct sdei_event *event; + atomic_t errors; + int first_error; +}; + +#define CROSSCALL_INIT(arg, event) (arg.event = event, \ + arg.first_error = 0, \ + atomic_set(&arg.errors, 0)) + +static inline int sdei_do_cross_call(void *fn, struct sdei_event * event) +{ + struct sdei_crosscall_args arg; + + CROSSCALL_INIT(arg, event); + on_each_cpu(fn, &arg, true); + + return arg.first_error; +} + +static inline void +sdei_cross_call_return(struct sdei_crosscall_args *arg, int err) +{ + if (err && (atomic_inc_return(&arg->errors) == 1)) + arg->first_error = err; +} + static int sdei_to_linux_errno(unsigned long sdei_err) { switch (sdei_err) { @@ -207,6 +243,26 @@ static struct sdei_event *sdei_event_create(u32 event_num, reg->callback = cb; reg->callback_arg = cb_arg; event->registered = reg; + } else { + int cpu; + struct sdei_registered_event __percpu *regs; + + regs = alloc_percpu(struct sdei_registered_event); + if (!regs) { + kfree(event); + return ERR_PTR(-ENOMEM); + } + + for_each_possible_cpu(cpu) { + reg = per_cpu_ptr(regs, cpu); + + reg->event_num = event->event_num; + reg->priority = event->priority; + reg->callback = cb; + reg->callback_arg = cb_arg; + } + + event->private_registered = regs; } if (sdei_event_find(event_num)) { @@ -232,6 +288,8 @@ static void sdei_event_destroy(struct sdei_event *event) if (event->type == SDEI_EVENT_TYPE_SHARED) kfree(event->registered); + else + free_percpu(event->private_registered); kfree(event); } @@ -262,11 +320,6 @@ static void _ipi_mask_cpu(void *ignored) sdei_mask_local_cpu(); } -static int sdei_cpuhp_down(unsigned int ignored) -{ - return sdei_mask_local_cpu(); -} - int sdei_unmask_local_cpu(void) { int err; @@ -288,11 +341,6 @@ static void _ipi_unmask_cpu(void *ignored) sdei_unmask_local_cpu(); } -static int sdei_cpuhp_up(unsigned int ignored) -{ - return sdei_unmask_local_cpu(); -} - static void _ipi_private_reset(void *ignored) { int err; @@ -337,6 +385,19 @@ static int sdei_api_event_enable(u32 event_num) 0, NULL); } +/* Called directly by the hotplug callbacks */ +static void _local_event_enable(void *data) +{ + int err; + struct sdei_crosscall_args *arg = data; + + WARN_ON_ONCE(preemptible()); + + err = sdei_api_event_enable(arg->event->event_num); + + sdei_cross_call_return(arg, err); +} + int sdei_event_enable(u32 event_num) { int err = -EINVAL; @@ -355,6 +416,8 @@ int sdei_event_enable(u32 event_num) if (event->type == SDEI_EVENT_TYPE_SHARED) err = sdei_api_event_enable(event->event_num); + else + err = sdei_do_cross_call(_local_event_enable, event); mutex_unlock(&sdei_events_lock); return err; @@ -367,6 +430,16 @@ static int sdei_api_event_disable(u32 event_num) 0, 0, NULL); } +static void _ipi_event_disable(void *data) +{ + int err; + struct sdei_crosscall_args *arg = data; + + err = sdei_api_event_disable(arg->event->event_num); + + sdei_cross_call_return(arg, err); +} + int sdei_event_disable(u32 event_num) { int err = -EINVAL; @@ -385,6 +458,8 @@ int sdei_event_disable(u32 event_num) if (event->type == SDEI_EVENT_TYPE_SHARED) err = sdei_api_event_disable(event->event_num); + else + err = sdei_do_cross_call(_ipi_event_disable, event); mutex_unlock(&sdei_events_lock); return err; @@ -397,6 +472,19 @@ static int sdei_api_event_unregister(u32 event_num) 0, 0, 0, NULL); } +/* Called directly by the hotplug callbacks */ +static void _local_event_unregister(void *data) +{ + int err; + struct sdei_crosscall_args *arg = data; + + WARN_ON_ONCE(preemptible()); + + err = sdei_api_event_unregister(arg->event->event_num); + + sdei_cross_call_return(arg, err); +} + static int _sdei_event_unregister(struct sdei_event *event) { lockdep_assert_held(&sdei_events_lock); @@ -409,7 +497,7 @@ static int _sdei_event_unregister(struct sdei_event *event) if (event->type == SDEI_EVENT_TYPE_SHARED) return sdei_api_event_unregister(event->event_num); - return -EINVAL; + return sdei_do_cross_call(_local_event_unregister, event); } int sdei_event_unregister(u32 event_num) @@ -473,17 +561,50 @@ static int sdei_api_event_register(u32 event_num, unsigned long entry_point, flags, affinity, NULL); } +/* Called directly by the hotplug callbacks */ +static void _local_event_register(void *data) +{ + int err; + struct sdei_registered_event *reg; + struct sdei_crosscall_args *arg = data; + + WARN_ON(preemptible()); + + reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id()); + err = sdei_api_event_register(arg->event->event_num, sdei_entry_point, + reg, 0, 0); + + sdei_cross_call_return(arg, err); +} + static int _sdei_event_register(struct sdei_event *event) { + int err; + lockdep_assert_held(&sdei_events_lock); + spin_lock(&sdei_list_lock); + event->reregister = true; + spin_unlock(&sdei_list_lock); + if (event->type == SDEI_EVENT_TYPE_SHARED) return sdei_api_event_register(event->event_num, sdei_entry_point, event->registered, SDEI_EVENT_REGISTER_RM_ANY, 0); - return -EINVAL; + + err = sdei_do_cross_call(_local_event_register, event); + if (err) { + spin_lock(&sdei_list_lock); + event->reregister = false; + event->reenable = false; + spin_unlock(&sdei_list_lock); + + sdei_do_cross_call(_local_event_unregister, event); + } + + return err; } int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg) @@ -538,6 +659,8 @@ static int sdei_reregister_event(struct sdei_event *event) if (event->reenable) { if (event->type == SDEI_EVENT_TYPE_SHARED) err = sdei_api_event_enable(event->event_num); + else + err = sdei_do_cross_call(_local_event_enable, event); } if (err) @@ -569,6 +692,62 @@ static int sdei_reregister_shared(void) return err; } +static int sdei_cpuhp_down(unsigned int cpu) +{ + struct sdei_event *event; + struct sdei_crosscall_args arg; + + /* un-register private events */ + spin_lock(&sdei_list_lock); + list_for_each_entry(event, &sdei_list, list) { + if (event->type == SDEI_EVENT_TYPE_SHARED) + continue; + + CROSSCALL_INIT(arg, event); + /* call the cross-call function locally... */ + _local_event_unregister(&arg); + if (arg.first_error) + pr_err("Failed to unregister event %u: %d\n", + event->event_num, arg.first_error); + } + spin_unlock(&sdei_list_lock); + + return sdei_mask_local_cpu(); +} + +static int sdei_cpuhp_up(unsigned int cpu) +{ + struct sdei_event *event; + struct sdei_crosscall_args arg; + + /* re-register/enable private events */ + spin_lock(&sdei_list_lock); + list_for_each_entry(event, &sdei_list, list) { + if (event->type == SDEI_EVENT_TYPE_SHARED) + continue; + + if (event->reregister) { + CROSSCALL_INIT(arg, event); + /* call the cross-call function locally... */ + _local_event_register(&arg); + if (arg.first_error) + pr_err("Failed to re-register event %u: %d\n", + event->event_num, arg.first_error); + } + + if (event->reenable) { + CROSSCALL_INIT(arg, event); + _local_event_enable(&arg); + if (arg.first_error) + pr_err("Failed to re-enable event %u: %d\n", + event->event_num, arg.first_error); + } + } + spin_unlock(&sdei_list_lock); + + return sdei_unmask_local_cpu(); +} + /* When entering idle, mask/unmask events for this cpu */ static int sdei_pm_notifier(struct notifier_block *nb, unsigned long action, void *data) @@ -622,6 +801,7 @@ static int sdei_device_freeze(struct device *dev) { int err; + /* unregister private events */ cpuhp_remove_state(CPUHP_AP_ARM_SDEI_STARTING); err = sdei_unregister_shared(); -- 2.20.1