It is preferred in the kernel to avoid using semaphores to wait for events as, they are optimised for the opposite situation; where the common case is that they are available and may block only occasionally. FYI see this thread: https://lkml.org/lkml/2008/4/11/323. Also completions are semantically more explicit in this case. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx> --- .../interface/vchiq_arm/vchiq_arm.c | 2 +- .../interface/vchiq_arm/vchiq_core.c | 94 +++++++++---------- .../interface/vchiq_arm/vchiq_core.h | 26 ++--- 3 files changed, 61 insertions(+), 61 deletions(-) diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c index 463d0eec2e96..383013a92939 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c @@ -2063,7 +2063,7 @@ vchiq_release(struct inode *inode, struct file *file) != NULL) { USER_SERVICE_T *user_service = service->base.userdata; - down(&service->remove_event); + wait_for_completion(&service->remove_event); BUG_ON(service->srvstate != VCHIQ_SRVSTATE_FREE); diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c index e8b7ccabd9cb..0c37b7032857 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c @@ -376,7 +376,7 @@ mark_service_closing_internal(VCHIQ_SERVICE_T *service, int sh_thread) /* Unblock any sending thread. */ service_quota = &state->service_quotas[service->localport]; - up(&service_quota->quota_event); + complete(&service_quota->quota_event); } static void @@ -423,7 +423,7 @@ remote_event_create(VCHIQ_STATE_T *state, REMOTE_EVENT_T *event) event->armed = 0; /* Don't clear the 'fired' flag because it may already have been set ** by the other side. */ - sema_init((struct semaphore *)((char *)state + event->event), 0); + init_completion((struct completion *)((char *)state + event->event)); } static inline int @@ -433,9 +433,9 @@ remote_event_wait(VCHIQ_STATE_T *state, REMOTE_EVENT_T *event) event->armed = 1; dsb(sy); if (!event->fired) { - if (down_interruptible( - (struct semaphore *) - ((char *)state + event->event)) != 0) { + if (wait_for_completion_interruptible( + (struct completion *) + ((char *)state + event->event))) { event->armed = 0; return 0; } @@ -452,7 +452,7 @@ static inline void remote_event_signal_local(VCHIQ_STATE_T *state, REMOTE_EVENT_T *event) { event->armed = 0; - up((struct semaphore *)((char *)state + event->event)); + complete((struct completion *)((char *)state + event->event)); } static inline void @@ -582,7 +582,7 @@ reserve_space(VCHIQ_STATE_T *state, size_t space, int is_blocking) /* If there is no free slot... */ - if (down_trylock(&state->slot_available_event) != 0) { + if (!try_wait_for_completion(&state->slot_available_event)) { /* ...wait for one. */ VCHIQ_STATS_INC(state, slot_stalls); @@ -593,13 +593,13 @@ reserve_space(VCHIQ_STATE_T *state, size_t space, int is_blocking) remote_event_signal(&state->remote->trigger); if (!is_blocking || - (down_interruptible( - &state->slot_available_event) != 0)) + (wait_for_completion_interruptible( + &state->slot_available_event))) return NULL; /* No space available */ } if (tx_pos == (state->slot_queue_available * VCHIQ_SLOT_SIZE)) { - up(&state->slot_available_event); + complete(&state->slot_available_event); pr_warn("%s: invalid tx_pos: %d\n", __func__, tx_pos); return NULL; } @@ -679,7 +679,7 @@ process_free_queue(VCHIQ_STATE_T *state, BITSET_T *service_found, size_t length) /* Signal the service that it ** has dropped below its quota */ - up(&service_quota->quota_event); + complete(&service_quota->quota_event); else if (count == 0) { vchiq_log_error(vchiq_core_log_level, "service %d message_use_count=%d (header %pK, msgid %x, header->msgid %x, header->size %x)", @@ -704,7 +704,7 @@ process_free_queue(VCHIQ_STATE_T *state, BITSET_T *service_found, size_t length) /* Signal the service in case ** it has dropped below its ** quota */ - up(&service_quota->quota_event); + complete(&service_quota->quota_event); vchiq_log_trace( vchiq_core_log_level, "%d: pfq:%d %x@%pK - slot_use->%d", @@ -745,7 +745,7 @@ process_free_queue(VCHIQ_STATE_T *state, BITSET_T *service_found, size_t length) count - 1; spin_unlock("a_spinlock); if (count == state->data_quota) - up(&state->data_quota_event); + complete(&state->data_quota_event); } /* @@ -755,7 +755,7 @@ process_free_queue(VCHIQ_STATE_T *state, BITSET_T *service_found, size_t length) mb(); state->slot_queue_available = slot_queue_available; - up(&state->slot_available_event); + complete(&state->slot_available_event); } } @@ -863,8 +863,8 @@ queue_message(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service, spin_unlock("a_spinlock); mutex_unlock(&state->slot_mutex); - if (down_interruptible(&state->data_quota_event) - != 0) + if (wait_for_completion_interruptible( + &state->data_quota_event)) return VCHIQ_RETRY; mutex_lock(&state->slot_mutex); @@ -874,7 +874,7 @@ queue_message(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service, if ((tx_end_index == state->previous_data_index) || (state->data_use_count < state->data_quota)) { /* Pass the signal on to other waiters */ - up(&state->data_quota_event); + complete(&state->data_quota_event); break; } } @@ -894,8 +894,8 @@ queue_message(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service, service_quota->slot_use_count); VCHIQ_SERVICE_STATS_INC(service, quota_stalls); mutex_unlock(&state->slot_mutex); - if (down_interruptible(&service_quota->quota_event) - != 0) + if (wait_for_completion_interruptible( + &service_quota->quota_event)) return VCHIQ_RETRY; if (service->closing) return VCHIQ_ERROR; @@ -1252,7 +1252,7 @@ notify_bulks(VCHIQ_SERVICE_T *service, VCHIQ_BULK_QUEUE_T *queue, waiter = bulk->userdata; if (waiter) { waiter->actual = bulk->actual; - up(&waiter->event); + complete(&waiter->event); } spin_unlock(&bulk_waiter_spinlock); } else if (bulk->mode == @@ -1275,7 +1275,7 @@ notify_bulks(VCHIQ_SERVICE_T *service, VCHIQ_BULK_QUEUE_T *queue, } queue->remove++; - up(&service->bulk_remove_event); + complete(&service->bulk_remove_event); } if (!retry_poll) status = VCHIQ_SUCCESS; @@ -1668,7 +1668,7 @@ parse_rx_slots(VCHIQ_STATE_T *state) service->remoteport = remoteport; vchiq_set_service_state(service, VCHIQ_SRVSTATE_OPEN); - up(&service->remove_event); + complete(&service->remove_event); } else vchiq_log_error(vchiq_core_log_level, "OPENACK received in state %s", @@ -1722,7 +1722,7 @@ parse_rx_slots(VCHIQ_STATE_T *state) "%d: prs CONNECT@%pK", state->id, header); state->version_common = ((VCHIQ_SLOT_ZERO_T *) state->slot_data)->version; - up(&state->connect); + complete(&state->connect); break; case VCHIQ_MSG_BULK_RX: case VCHIQ_MSG_BULK_TX: @@ -2056,7 +2056,7 @@ sync_func(void *v) vchiq_set_service_state(service, VCHIQ_SRVSTATE_OPENSYNC); service->sync = 1; - up(&service->remove_event); + complete(&service->remove_event); } release_message_sync(state, header); break; @@ -2195,28 +2195,28 @@ vchiq_init_state(VCHIQ_STATE_T *state, VCHIQ_SLOT_ZERO_T *slot_zero) initialize events and mutexes */ - sema_init(&state->connect, 0); + init_completion(&state->connect); mutex_init(&state->mutex); mutex_init(&state->slot_mutex); mutex_init(&state->recycle_mutex); mutex_init(&state->sync_mutex); mutex_init(&state->bulk_transfer_mutex); - sema_init(&state->slot_available_event, 0); - sema_init(&state->slot_remove_event, 0); - sema_init(&state->data_quota_event, 0); + init_completion(&state->slot_available_event); + init_completion(&state->slot_remove_event); + init_completion(&state->data_quota_event); state->slot_queue_available = 0; for (i = 0; i < VCHIQ_MAX_SERVICES; i++) { VCHIQ_SERVICE_QUOTA_T *service_quota = &state->service_quotas[i]; - sema_init(&service_quota->quota_event, 0); + init_completion(&service_quota->quota_event); } for (i = local->slot_first; i <= local->slot_last; i++) { local->slot_queue[state->slot_queue_available++] = i; - up(&state->slot_available_event); + complete(&state->slot_available_event); } state->default_slot_quota = state->slot_queue_available/2; @@ -2350,8 +2350,8 @@ vchiq_add_service_internal(VCHIQ_STATE_T *state, service->service_use_count = 0; init_bulk_queue(&service->bulk_tx); init_bulk_queue(&service->bulk_rx); - sema_init(&service->remove_event, 0); - sema_init(&service->bulk_remove_event, 0); + init_completion(&service->remove_event); + init_completion(&service->bulk_remove_event); mutex_init(&service->bulk_mutex); memset(&service->stats, 0, sizeof(service->stats)); @@ -2466,7 +2466,7 @@ vchiq_open_service_internal(VCHIQ_SERVICE_T *service, int client_id) QMFLAGS_IS_BLOCKING); if (status == VCHIQ_SUCCESS) { /* Wait for the ACK/NAK */ - if (down_interruptible(&service->remove_event) != 0) { + if (wait_for_completion_interruptible(&service->remove_event)) { status = VCHIQ_RETRY; vchiq_release_service_internal(service); } else if ((service->srvstate != VCHIQ_SRVSTATE_OPEN) && @@ -2618,7 +2618,7 @@ close_service_complete(VCHIQ_SERVICE_T *service, int failstate) if (is_server) service->closing = 0; - up(&service->remove_event); + complete(&service->remove_event); } } else vchiq_set_service_state(service, failstate); @@ -2659,7 +2659,7 @@ vchiq_close_service_internal(VCHIQ_SERVICE_T *service, int close_recvd) vchiq_set_service_state(service, VCHIQ_SRVSTATE_LISTENING); } - up(&service->remove_event); + complete(&service->remove_event); } else vchiq_free_service_internal(service); break; @@ -2668,7 +2668,7 @@ vchiq_close_service_internal(VCHIQ_SERVICE_T *service, int close_recvd) /* The open was rejected - tell the user */ vchiq_set_service_state(service, VCHIQ_SRVSTATE_CLOSEWAIT); - up(&service->remove_event); + complete(&service->remove_event); } else { /* Shutdown mid-open - let the other side know */ status = queue_message(state, service, @@ -2801,7 +2801,7 @@ vchiq_free_service_internal(VCHIQ_SERVICE_T *service) vchiq_set_service_state(service, VCHIQ_SRVSTATE_FREE); - up(&service->remove_event); + complete(&service->remove_event); /* Release the initial lock */ unlock_service(service); @@ -2833,11 +2833,11 @@ vchiq_connect_internal(VCHIQ_STATE_T *state, VCHIQ_INSTANCE_T instance) } if (state->conn_state == VCHIQ_CONNSTATE_CONNECTING) { - if (down_interruptible(&state->connect) != 0) + if (wait_for_completion_interruptible(&state->connect)) return VCHIQ_RETRY; vchiq_set_conn_state(state, VCHIQ_CONNSTATE_CONNECTED); - up(&state->connect); + complete(&state->connect); } return VCHIQ_SUCCESS; @@ -2932,7 +2932,7 @@ vchiq_close_service(VCHIQ_SERVICE_HANDLE_T handle) } while (1) { - if (down_interruptible(&service->remove_event) != 0) { + if (wait_for_completion_interruptible(&service->remove_event)) { status = VCHIQ_RETRY; break; } @@ -2993,7 +2993,7 @@ vchiq_remove_service(VCHIQ_SERVICE_HANDLE_T handle) request_poll(service->state, service, VCHIQ_POLL_REMOVE); } while (1) { - if (down_interruptible(&service->remove_event) != 0) { + if (wait_for_completion_interruptible(&service->remove_event)) { status = VCHIQ_RETRY; break; } @@ -3050,7 +3050,7 @@ VCHIQ_STATUS_T vchiq_bulk_transfer(VCHIQ_SERVICE_HANDLE_T handle, break; case VCHIQ_BULK_MODE_BLOCKING: bulk_waiter = (struct bulk_waiter *)userdata; - sema_init(&bulk_waiter->event, 0); + init_completion(&bulk_waiter->event); bulk_waiter->actual = 0; bulk_waiter->bulk = NULL; break; @@ -3076,8 +3076,8 @@ VCHIQ_STATUS_T vchiq_bulk_transfer(VCHIQ_SERVICE_HANDLE_T handle, VCHIQ_SERVICE_STATS_INC(service, bulk_stalls); do { mutex_unlock(&service->bulk_mutex); - if (down_interruptible(&service->bulk_remove_event) - != 0) { + if (wait_for_completion_interruptible( + &service->bulk_remove_event)) { status = VCHIQ_RETRY; goto error_exit; } @@ -3153,7 +3153,7 @@ VCHIQ_STATUS_T vchiq_bulk_transfer(VCHIQ_SERVICE_HANDLE_T handle, if (bulk_waiter) { bulk_waiter->bulk = bulk; - if (down_interruptible(&bulk_waiter->event) != 0) + if (wait_for_completion_interruptible(&bulk_waiter->event)) status = VCHIQ_RETRY; else if (bulk_waiter->actual == VCHIQ_BULK_ACTUAL_ABORTED) status = VCHIQ_ERROR; @@ -3322,7 +3322,7 @@ vchiq_set_service_option(VCHIQ_SERVICE_HANDLE_T handle, service_quota->message_use_count)) { /* Signal the service that it may have ** dropped below its quota */ - up(&service_quota->quota_event); + complete(&service_quota->quota_event); } status = VCHIQ_SUCCESS; } @@ -3343,7 +3343,7 @@ vchiq_set_service_option(VCHIQ_SERVICE_HANDLE_T handle, service_quota->slot_use_count)) /* Signal the service that it may have ** dropped below its quota */ - up(&service_quota->quota_event); + complete(&service_quota->quota_event); status = VCHIQ_SUCCESS; } } break; diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h index 5b1696422e21..b76281f7510e 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h @@ -35,7 +35,7 @@ #define VCHIQ_CORE_H #include <linux/mutex.h> -#include <linux/semaphore.h> +#include <linux/completion.h> #include <linux/kthread.h> #include "vchiq_cfg.h" @@ -307,8 +307,8 @@ typedef struct vchiq_service_struct { VCHIQ_BULK_QUEUE_T bulk_tx; VCHIQ_BULK_QUEUE_T bulk_rx; - struct semaphore remove_event; - struct semaphore bulk_remove_event; + struct completion remove_event; + struct completion bulk_remove_event; struct mutex bulk_mutex; struct service_stats_struct { @@ -337,7 +337,7 @@ typedef struct vchiq_service_quota_struct { unsigned short slot_use_count; unsigned short message_quota; unsigned short message_use_count; - struct semaphore quota_event; + struct completion quota_event; int previous_tx_index; } VCHIQ_SERVICE_QUOTA_T; @@ -410,7 +410,7 @@ struct vchiq_state_struct { unsigned short default_message_quota; /* Event indicating connect message received */ - struct semaphore connect; + struct completion connect; /* Mutex protecting services */ struct mutex mutex; @@ -426,16 +426,16 @@ struct vchiq_state_struct { struct task_struct *sync_thread; /* Local implementation of the trigger remote event */ - struct semaphore trigger_event; + struct completion trigger_event; /* Local implementation of the recycle remote event */ - struct semaphore recycle_event; + struct completion recycle_event; /* Local implementation of the sync trigger remote event */ - struct semaphore sync_trigger_event; + struct completion sync_trigger_event; /* Local implementation of the sync release remote event */ - struct semaphore sync_release_event; + struct completion sync_release_event; char *tx_data; char *rx_data; @@ -481,12 +481,12 @@ struct vchiq_state_struct { int unused_service; /* Signalled when a free slot becomes available. */ - struct semaphore slot_available_event; + struct completion slot_available_event; - struct semaphore slot_remove_event; + struct completion slot_remove_event; /* Signalled when a free data slot becomes available. */ - struct semaphore data_quota_event; + struct completion data_quota_event; struct state_stats_struct { int slot_stalls; @@ -505,7 +505,7 @@ struct vchiq_state_struct { struct bulk_waiter { VCHIQ_BULK_T *bulk; - struct semaphore event; + struct completion event; int actual; }; -- 2.19.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
