Commit 88a6ab1d authored by Stefan Wahren's avatar Stefan Wahren Committed by Greg Kroah-Hartman
Browse files

staging: vchiq_core: introduce process_free_data_message 



This moves the special handling for data messages from process_free_queue()
into a new function. After this process_free_queue() has less extreme
indentation and should be easier to read.

Signed-off-by: default avatarStefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1622735405-9980-13-git-send-email-stefan.wahren@i2se.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 68a48596

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c

+64 −60
Original line number Diff line number Diff line
@@ -717,59 +717,13 @@ reserve_space(struct vchiq_state *state, size_t space, int is_blocking) 
						(tx_pos & VCHIQ_SLOT_MASK));

}



/* Called by the recycle thread. */

static void

process_free_queue(struct vchiq_state *state, BITSET_T *service_found,

		   size_t length)

process_free_data_message(struct vchiq_state *state, BITSET_T *service_found,

			  struct vchiq_header *header)

{

	struct vchiq_shared_state *local = state->local;

	int slot_queue_available;



	/*

	 * Find slots which have been freed by the other side, and return them

	 * to the available queue.

	 */

	slot_queue_available = state->slot_queue_available;



	/*

	 * Use a memory barrier to ensure that any state that may have been

	 * modified by another thread is not masked by stale prefetched

	 * values.

	 */

	mb();



	while (slot_queue_available != local->slot_queue_recycle) {

		unsigned int pos;

		int slot_index = local->slot_queue[slot_queue_available &

			VCHIQ_SLOT_QUEUE_MASK];

		char *data = (char *)SLOT_DATA_FROM_INDEX(state, slot_index);

		int data_found = 0;



		slot_queue_available++;

		/*

		 * Beware of the address dependency - data is calculated

		 * using an index written by the other side.

		 */

		rmb();



		vchiq_log_trace(vchiq_core_log_level, "%d: pfq %d=%pK %x %x",

			state->id, slot_index, data,

			local->slot_queue_recycle, slot_queue_available);



		/* Initialise the bitmask for services which have used this slot */

		memset(service_found, 0, length);



		pos = 0;



		while (pos < VCHIQ_SLOT_SIZE) {

			struct vchiq_header *header =

				(struct vchiq_header *)(data + pos);

	int msgid = header->msgid;



			if (VCHIQ_MSG_TYPE(msgid) == VCHIQ_MSG_DATA) {

	int port = VCHIQ_MSG_SRCPORT(msgid);

				struct vchiq_service_quota *quota =

					&state->service_quotas[port];

	struct vchiq_service_quota *quota = &state->service_quotas[port];

	int count;



	spin_lock(&quota_spinlock);
@@ -800,8 +754,7 @@ process_free_queue(struct vchiq_state *state, BITSET_T *service_found, 
		spin_lock(&quota_spinlock);

		count = quota->slot_use_count;

		if (count > 0)

						quota->slot_use_count =

							count - 1;

			quota->slot_use_count = count - 1;

		spin_unlock(&quota_spinlock);



		if (count > 0) {
@@ -810,15 +763,13 @@ process_free_queue(struct vchiq_state *state, BITSET_T *service_found, 
			 * it has dropped below its quota

			 */

			complete(&quota->quota_event);

						vchiq_log_trace(

							vchiq_core_log_level,

			vchiq_log_trace(vchiq_core_log_level,

				"%d: pfq:%d %x@%pK - slot_use->%d",

				state->id, port,

				header->size, header,

				count - 1);

		} else {

						vchiq_log_error(

							vchiq_core_log_level,

			vchiq_log_error(vchiq_core_log_level,

					"service %d slot_use_count=%d (header %pK, msgid %x, header->msgid %x, header->size %x)",

				port, count, header,

				msgid, header->msgid,
@@ -826,7 +777,60 @@ process_free_queue(struct vchiq_state *state, BITSET_T *service_found, 
			WARN(1, "bad slot use count\n");

		}

	}

}



/* Called by the recycle thread. */

static void

process_free_queue(struct vchiq_state *state, BITSET_T *service_found,

		   size_t length)

{

	struct vchiq_shared_state *local = state->local;

	int slot_queue_available;



	/*

	 * Find slots which have been freed by the other side, and return them

	 * to the available queue.

	 */

	slot_queue_available = state->slot_queue_available;



	/*

	 * Use a memory barrier to ensure that any state that may have been

	 * modified by another thread is not masked by stale prefetched

	 * values.

	 */

	mb();



	while (slot_queue_available != local->slot_queue_recycle) {

		unsigned int pos;

		int slot_index = local->slot_queue[slot_queue_available &

			VCHIQ_SLOT_QUEUE_MASK];

		char *data = (char *)SLOT_DATA_FROM_INDEX(state, slot_index);

		int data_found = 0;



		slot_queue_available++;

		/*

		 * Beware of the address dependency - data is calculated

		 * using an index written by the other side.

		 */

		rmb();



		vchiq_log_trace(vchiq_core_log_level, "%d: pfq %d=%pK %x %x",

			state->id, slot_index, data,

			local->slot_queue_recycle, slot_queue_available);



		/* Initialise the bitmask for services which have used this slot */

		memset(service_found, 0, length);



		pos = 0;



		while (pos < VCHIQ_SLOT_SIZE) {

			struct vchiq_header *header =

				(struct vchiq_header *)(data + pos);

			int msgid = header->msgid;



			if (VCHIQ_MSG_TYPE(msgid) == VCHIQ_MSG_DATA) {

				process_free_data_message(state, service_found,

							  header);

				data_found = 1;

			}