[PATCH 11/16] staging: vchiq: use completions instead of semaphores

From: Nicolas Saenz Julienne
Date: Wed Nov 14 2018 - 08:00:52 EST

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 | 60 ++++++-----
.../interface/vchiq_arm/vchiq_core.c | 100 +++++++++---------
.../interface/vchiq_arm/vchiq_core.h | 26 ++---
.../interface/vchiq_arm/vchiq_util.c | 16 +--
.../interface/vchiq_arm/vchiq_util.h | 6 +-
5 files changed, 106 insertions(+), 102 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 1cdfdb714abc..383013a92939 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -44,7 +44,7 @@
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/bug.h>
-#include <linux/semaphore.h>
+#include <linux/completion.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/platform_device.h>
@@ -121,9 +121,9 @@ typedef struct user_service_struct {
int message_available_pos;
int msg_insert;
int msg_remove;
- struct semaphore insert_event;
- struct semaphore remove_event;
- struct semaphore close_event;
+ struct completion insert_event;
+ struct completion remove_event;
+ struct completion close_event;
VCHIQ_HEADER_T * msg_queue[MSG_QUEUE_SIZE];
} USER_SERVICE_T;

@@ -138,8 +138,8 @@ struct vchiq_instance_struct {
VCHIQ_COMPLETION_DATA_T completions[MAX_COMPLETIONS];
int completion_insert;
int completion_remove;
- struct semaphore insert_event;
- struct semaphore remove_event;
+ struct completion insert_event;
+ struct completion remove_event;
struct mutex completion_mutex;

int connected;
@@ -562,7 +562,8 @@ add_completion(VCHIQ_INSTANCE_T instance, VCHIQ_REASON_T reason,
vchiq_log_trace(vchiq_arm_log_level,
"%s - completion queue full", __func__);
DEBUG_COUNT(COMPLETION_QUEUE_FULL_COUNT);
- if (down_interruptible(&instance->remove_event) != 0) {
+ if (wait_for_completion_interruptible(
+ &instance->remove_event)) {
vchiq_log_info(vchiq_arm_log_level,
"service_callback interrupted");
return VCHIQ_RETRY;
@@ -600,7 +601,7 @@ add_completion(VCHIQ_INSTANCE_T instance, VCHIQ_REASON_T reason,
insert++;
instance->completion_insert = insert;

- up(&instance->insert_event);
+ complete(&instance->insert_event);

return VCHIQ_SUCCESS;
}
@@ -673,7 +674,8 @@ service_callback(VCHIQ_REASON_T reason, VCHIQ_HEADER_T *header,
}

DEBUG_TRACE(SERVICE_CALLBACK_LINE);
- if (down_interruptible(&user_service->remove_event)
+ if (wait_for_completion_interruptible(
+ &user_service->remove_event)
!= 0) {
vchiq_log_info(vchiq_arm_log_level,
"%s interrupted", __func__);
@@ -705,7 +707,7 @@ service_callback(VCHIQ_REASON_T reason, VCHIQ_HEADER_T *header,
}

spin_unlock(&msg_queue_spinlock);
- up(&user_service->insert_event);
+ complete(&user_service->insert_event);

header = NULL;
}
@@ -745,7 +747,7 @@ static void close_delivered(USER_SERVICE_T *user_service)
unlock_service(user_service->service);

/* Wake the user-thread blocked in close_ or remove_service */
- up(&user_service->close_event);
+ complete(&user_service->close_event);

user_service->close_pending = 0;
}
@@ -867,7 +869,7 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if (status == VCHIQ_SUCCESS) {
/* Wake the completion thread and ask it to exit */
instance->closing = 1;
- up(&instance->insert_event);
+ complete(&instance->insert_event);
}

break;
@@ -948,9 +950,9 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
instance->completion_remove - 1;
user_service->msg_insert = 0;
user_service->msg_remove = 0;
- sema_init(&user_service->insert_event, 0);
- sema_init(&user_service->remove_event, 0);
- sema_init(&user_service->close_event, 0);
+ init_completion(&user_service->insert_event);
+ init_completion(&user_service->remove_event);
+ init_completion(&user_service->close_event);

if (args.is_open) {
status = vchiq_open_service_internal
@@ -1007,7 +1009,8 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
has been closed until the client library calls the
CLOSE_DELIVERED ioctl, signalling close_event. */
if (user_service->close_pending &&
- down_interruptible(&user_service->close_event))
+ wait_for_completion_interruptible(
+ &user_service->close_event))
status = VCHIQ_RETRY;
break;
}
@@ -1182,7 +1185,8 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

DEBUG_TRACE(AWAIT_COMPLETION_LINE);
mutex_unlock(&instance->completion_mutex);
- rc = down_interruptible(&instance->insert_event);
+ rc = wait_for_completion_interruptible(
+ &instance->insert_event);
mutex_lock(&instance->completion_mutex);
if (rc != 0) {
DEBUG_TRACE(AWAIT_COMPLETION_LINE);
@@ -1310,7 +1314,7 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}

if (ret != 0)
- up(&instance->remove_event);
+ complete(&instance->remove_event);
mutex_unlock(&instance->completion_mutex);
DEBUG_TRACE(AWAIT_COMPLETION_LINE);
} break;
@@ -1350,8 +1354,8 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
do {
spin_unlock(&msg_queue_spinlock);
DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
- if (down_interruptible(
- &user_service->insert_event) != 0) {
+ if (wait_for_completion_interruptible(
+ &user_service->insert_event)) {
vchiq_log_info(vchiq_arm_log_level,
"DEQUEUE_MESSAGE interrupted");
ret = -EINTR;
@@ -1373,7 +1377,7 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
user_service->msg_remove++;
spin_unlock(&msg_queue_spinlock);

- up(&user_service->remove_event);
+ complete(&user_service->remove_event);
if (header == NULL)
ret = -ENOTCONN;
else if (header->size <= args.bufsize) {
@@ -1979,8 +1983,8 @@ vchiq_open(struct inode *inode, struct file *file)

vchiq_debugfs_add_instance(instance);

- sema_init(&instance->insert_event, 0);
- sema_init(&instance->remove_event, 0);
+ init_completion(&instance->insert_event);
+ init_completion(&instance->remove_event);
mutex_init(&instance->completion_mutex);
mutex_init(&instance->bulk_waiter_list_mutex);
INIT_LIST_HEAD(&instance->bulk_waiter_list);
@@ -2033,12 +2037,12 @@ vchiq_release(struct inode *inode, struct file *file)

/* Wake the completion thread and ask it to exit */
instance->closing = 1;
- up(&instance->insert_event);
+ complete(&instance->insert_event);

mutex_unlock(&instance->completion_mutex);

/* Wake the slot handler if the completion queue is full. */
- up(&instance->remove_event);
+ complete(&instance->remove_event);

/* Mark all services for termination... */
i = 0;
@@ -2047,7 +2051,7 @@ vchiq_release(struct inode *inode, struct file *file)
USER_SERVICE_T *user_service = service->base.userdata;

/* Wake the slot handler if the msg queue is full. */
- up(&user_service->remove_event);
+ complete(&user_service->remove_event);

vchiq_terminate_service_internal(service);
unlock_service(service);
@@ -2059,7 +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);

@@ -2103,7 +2107,7 @@ vchiq_release(struct inode *inode, struct file *file)

/* Wake any blocked user-thread */
if (instance->use_close_delivered)
- up(&user_service->close_event);
+ complete(&user_service->close_event);
unlock_service(service);
}
instance->completion_remove++;
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 5791c2b670fa..a45cdd08e209 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
@@ -432,9 +432,9 @@ 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;
}
@@ -451,7 +451,7 @@ 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
@@ -581,7 +581,7 @@ 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);
@@ -592,13 +592,13 @@ 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;
}
@@ -678,7 +678,7 @@ 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)",
@@ -703,7 +703,7 @@ 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",
@@ -744,7 +744,7 @@ process_free_queue(VCHIQ_STATE_T *state, BITSET_T *service_found, size_t length)
count - 1;
spin_unlock(&quota_spinlock);
if (count == state->data_quota)
- up(&state->data_quota_event);
+ complete(&state->data_quota_event);
}

/*
@@ -754,7 +754,7 @@ 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);
}
}

@@ -862,8 +862,8 @@ queue_message(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service,
spin_unlock(&quota_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);
@@ -873,7 +873,7 @@ 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;
}
}
@@ -893,8 +893,8 @@ 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;
@@ -1251,7 +1251,7 @@ 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 ==
@@ -1274,7 +1274,7 @@ 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;
@@ -1667,7 +1667,7 @@ 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",
@@ -1721,7 +1721,7 @@ 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:
@@ -2055,7 +2055,7 @@ 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;
@@ -2194,33 +2194,33 @@ 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);
- sema_init(&state->trigger_event, 0);
- sema_init(&state->recycle_event, 0);
- sema_init(&state->sync_trigger_event, 0);
- sema_init(&state->sync_release_event, 0);
+ init_completion(&state->trigger_event);
+ init_completion(&state->recycle_event);
+ init_completion(&state->sync_trigger_event);
+ init_completion(&state->sync_release_event);

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;
@@ -2354,8 +2354,8 @@ 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));

@@ -2470,7 +2470,7 @@ 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) &&
@@ -2622,7 +2622,7 @@ 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);
@@ -2663,7 +2663,7 @@ 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;
@@ -2672,7 +2672,7 @@ 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,
@@ -2805,7 +2805,7 @@ 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);
@@ -2837,11 +2837,11 @@ 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;
@@ -2936,7 +2936,7 @@ 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;
}
@@ -2997,7 +2997,7 @@ 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;
}
@@ -3054,7 +3054,7 @@ 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;
@@ -3080,8 +3080,8 @@ 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;
}
@@ -3157,7 +3157,7 @@ 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;
@@ -3326,7 +3326,7 @@ 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;
}
@@ -3347,7 +3347,7 @@ 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;
};

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c
index 2e52f07bbaa9..44b954daa74a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c
@@ -48,8 +48,8 @@ int vchiu_queue_init(VCHIU_QUEUE_T *queue, int size)
queue->write = 0;
queue->initialized = 1;

- sema_init(&queue->pop, 0);
- sema_init(&queue->push, 0);
+ init_completion(&queue->pop);
+ init_completion(&queue->push);

queue->storage = kcalloc(size, sizeof(VCHIQ_HEADER_T *), GFP_KERNEL);
if (!queue->storage) {
@@ -80,7 +80,7 @@ void vchiu_queue_push(VCHIU_QUEUE_T *queue, VCHIQ_HEADER_T *header)
return;

while (queue->write == queue->read + queue->size) {
- if (down_interruptible(&queue->pop) != 0)
+ if (wait_for_completion_interruptible(&queue->pop))
flush_signals(current);
}

@@ -100,17 +100,17 @@ void vchiu_queue_push(VCHIU_QUEUE_T *queue, VCHIQ_HEADER_T *header)

queue->write++;

- up(&queue->push);
+ complete(&queue->push);
}

VCHIQ_HEADER_T *vchiu_queue_peek(VCHIU_QUEUE_T *queue)
{
while (queue->write == queue->read) {
- if (down_interruptible(&queue->push) != 0)
+ if (wait_for_completion_interruptible(&queue->push))
flush_signals(current);
}

- up(&queue->push); // We haven't removed anything from the queue.
+ complete(&queue->push); // We haven't removed anything from the queue.

/*
* Read from queue->storage must be visible after read from
@@ -126,7 +126,7 @@ VCHIQ_HEADER_T *vchiu_queue_pop(VCHIU_QUEUE_T *queue)
VCHIQ_HEADER_T *header;

while (queue->write == queue->read) {
- if (down_interruptible(&queue->push) != 0)
+ if (wait_for_completion_interruptible(&queue->push))
flush_signals(current);
}

@@ -146,7 +146,7 @@ VCHIQ_HEADER_T *vchiu_queue_pop(VCHIU_QUEUE_T *queue)

queue->read++;

- up(&queue->pop);
+ complete(&queue->pop);

return header;
}
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.h b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.h
index 5a1540d349d3..b226227fe5bc 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.h
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.h
@@ -35,7 +35,7 @@
#define VCHIQ_UTIL_H

#include <linux/types.h>
-#include <linux/semaphore.h>
+#include <linux/completion.h>
#include <linux/mutex.h>
#include <linux/bitops.h>
#include <linux/kthread.h>
@@ -60,8 +60,8 @@ typedef struct {
int write;
int initialized;

- struct semaphore pop;
- struct semaphore push;
+ struct completion pop;
+ struct completion push;

VCHIQ_HEADER_T **storage;
} VCHIU_QUEUE_T;
--
2.19.1