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 <nsaenzjulie...@suse.de>
---
.../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
