sfc: Separate out queue-empty check from efx_nic_may_push_tx_desc() (306a2782) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/net/ethernet/sfc/nic.h

+22 −6

Original line number	Original line	Diff line number	Diff line
	@@ -71,6 +71,26 @@ efx_tx_desc(struct efx_tx_queue *tx_queue, unsigned int index)
	return ((efx_qword_t *) (tx_queue->txd.buf.addr)) + index;		return ((efx_qword_t *) (tx_queue->txd.buf.addr)) + index;
	}		}

			/* Report whether the NIC considers this TX queue empty, given the
			* write_count used for the last doorbell push. May return false
			* negative.
			*/
			static inline bool __efx_nic_tx_is_empty(struct efx_tx_queue *tx_queue,
			unsigned int write_count)
			{
			unsigned int empty_read_count = ACCESS_ONCE(tx_queue->empty_read_count);

			if (empty_read_count == 0)
			return false;

			return ((empty_read_count ^ write_count) & ~EFX_EMPTY_COUNT_VALID) == 0;
			}

			static inline bool efx_nic_tx_is_empty(struct efx_tx_queue *tx_queue)
			{
			return __efx_nic_tx_is_empty(tx_queue, tx_queue->write_count);
			}

	/* Decide whether to push a TX descriptor to the NIC vs merely writing		/* Decide whether to push a TX descriptor to the NIC vs merely writing
	* the doorbell. This can reduce latency when we are adding a single		* the doorbell. This can reduce latency when we are adding a single
	* descriptor to an empty queue, but is otherwise pointless. Further,		* descriptor to an empty queue, but is otherwise pointless. Further,
	@@ -80,14 +100,10 @@ efx_tx_desc(struct efx_tx_queue *tx_queue, unsigned int index)
	static inline bool efx_nic_may_push_tx_desc(struct efx_tx_queue *tx_queue,		static inline bool efx_nic_may_push_tx_desc(struct efx_tx_queue *tx_queue,
	unsigned int write_count)		unsigned int write_count)
	{		{
	unsigned empty_read_count = ACCESS_ONCE(tx_queue->empty_read_count);		bool was_empty = __efx_nic_tx_is_empty(tx_queue, write_count);

	if (empty_read_count == 0)
	return false;

	tx_queue->empty_read_count = 0;		tx_queue->empty_read_count = 0;
	return ((empty_read_count ^ write_count) & ~EFX_EMPTY_COUNT_VALID) == 0		return was_empty && tx_queue->write_count - write_count == 1;
	&& tx_queue->write_count - write_count == 1;
	}		}

	/* Returns a pointer to the specified descriptor in the RX descriptor queue */		/* Returns a pointer to the specified descriptor in the RX descriptor queue */