Commit 4752c93c authored by Mohamed Abbas's avatar Mohamed Abbas Committed by John W. Linville
Browse files

iwlcore: Allow skb allocation from tasklet. 



If RX queue becomes empty then we need to restock the queue from tasklet to prevent
ucode from starving. A caller to iwl_rx_allocate will decide if allocated buffer should
come from GFP_ATOMIC or GFP_KERNEL.

Signed-off-by: default avatarMohamed Abbas <mohamed.abbas@intel.com>
Signed-off-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent ef850d7c

drivers/net/wireless/iwlwifi/iwl-agn.c

+12 −3
Original line number Diff line number Diff line
@@ -831,6 +831,7 @@ void iwl_rx_handle(struct iwl_priv *priv) 
	unsigned long flags;

	u8 fill_rx = 0;

	u32 count = 8;

	int total_empty;



	/* uCode's read index (stored in shared DRAM) indicates the last Rx

	 * buffer that the driver may process (last buffer filled by ucode). */
@@ -841,7 +842,12 @@ void iwl_rx_handle(struct iwl_priv *priv) 
	if (i == r)

		IWL_DEBUG_RX(priv, "r = %d, i = %d\n", r, i);



	if (iwl_rx_queue_space(rxq) > (RX_QUEUE_SIZE / 2))

	/* calculate total frames need to be restock after handling RX */

	total_empty = r - priv->rxq.write_actual;

	if (total_empty < 0)

		total_empty += RX_QUEUE_SIZE;



	if (total_empty > (RX_QUEUE_SIZE / 2))

		fill_rx = 1;



	while (i != r) {
@@ -918,7 +924,7 @@ void iwl_rx_handle(struct iwl_priv *priv) 
			count++;

			if (count >= 8) {

				priv->rxq.read = i;

				iwl_rx_queue_restock(priv);

				iwl_rx_replenish_now(priv);

				count = 0;

			}

		}
@@ -926,6 +932,9 @@ void iwl_rx_handle(struct iwl_priv *priv) 


	/* Backtrack one entry */

	priv->rxq.read = i;

	if (fill_rx)

		iwl_rx_replenish_now(priv);

	else

		iwl_rx_queue_restock(priv);

}

drivers/net/wireless/iwlwifi/iwl-core.h

+2 −1
Original line number Diff line number Diff line
@@ -318,10 +318,11 @@ int iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, 
				  struct iwl_rx_queue *q);

void iwl_rx_queue_reset(struct iwl_priv *priv, struct iwl_rx_queue *rxq);

void iwl_rx_replenish(struct iwl_priv *priv);

void iwl_rx_replenish_now(struct iwl_priv *priv);

int iwl_rx_init(struct iwl_priv *priv, struct iwl_rx_queue *rxq);

int iwl_rx_queue_restock(struct iwl_priv *priv);

int iwl_rx_queue_space(const struct iwl_rx_queue *q);

void iwl_rx_allocate(struct iwl_priv *priv);

void iwl_rx_allocate(struct iwl_priv *priv, gfp_t priority);

void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb);

int iwl_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index);

/* Handlers */

drivers/net/wireless/iwlwifi/iwl-dev.h

+1 −0
Original line number Diff line number Diff line
@@ -382,6 +382,7 @@ struct iwl_rx_queue { 
	u32 read;

	u32 write;

	u32 free_count;

	u32 write_actual;

	struct list_head rx_free;

	struct list_head rx_used;

	int need_update;

drivers/net/wireless/iwlwifi/iwl-rx.c

+19 −6
Original line number Diff line number Diff line
@@ -145,12 +145,14 @@ int iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl_rx_queue *q) 
			goto exit_unlock;

		}



		iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write & ~0x7);

		q->write_actual = (q->write & ~0x7);

		iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);



	/* Else device is assumed to be awake */

	} else {

		/* Device expects a multiple of 8 */

		iwl_write32(priv, rx_wrt_ptr_reg, q->write & ~0x7);

		q->write_actual = (q->write & ~0x7);

		iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);

	}



	q->need_update = 0;
@@ -212,7 +214,7 @@ int iwl_rx_queue_restock(struct iwl_priv *priv) 


	/* If we've added more space for the firmware to place data, tell it.

	 * Increment device's write pointer in multiples of 8. */

	if (write != (rxq->write & ~0x7)) {

	if (rxq->write_actual != (rxq->write & ~0x7)) {

		spin_lock_irqsave(&rxq->lock, flags);

		rxq->need_update = 1;

		spin_unlock_irqrestore(&rxq->lock, flags);
@@ -232,7 +234,7 @@ EXPORT_SYMBOL(iwl_rx_queue_restock); 
 * Also restock the Rx queue via iwl_rx_queue_restock.

 * This is called as a scheduled work item (except for during initialization)

 */

void iwl_rx_allocate(struct iwl_priv *priv)

void iwl_rx_allocate(struct iwl_priv *priv, gfp_t priority)

{

	struct iwl_rx_queue *rxq = &priv->rxq;

	struct list_head *element;
@@ -254,7 +256,8 @@ void iwl_rx_allocate(struct iwl_priv *priv) 


		/* Alloc a new receive buffer */

		rxb->skb = alloc_skb(priv->hw_params.rx_buf_size + 256,

				     GFP_KERNEL);

						priority);



		if (!rxb->skb) {

			IWL_CRIT(priv, "Can not allocate SKB buffers\n");

			/* We don't reschedule replenish work here -- we will
@@ -289,7 +292,7 @@ void iwl_rx_replenish(struct iwl_priv *priv) 
{

	unsigned long flags;



	iwl_rx_allocate(priv);

	iwl_rx_allocate(priv, GFP_KERNEL);



	spin_lock_irqsave(&priv->lock, flags);

	iwl_rx_queue_restock(priv);
@@ -297,6 +300,14 @@ void iwl_rx_replenish(struct iwl_priv *priv) 
}

EXPORT_SYMBOL(iwl_rx_replenish);



void iwl_rx_replenish_now(struct iwl_priv *priv)

{

	iwl_rx_allocate(priv, GFP_ATOMIC);



	iwl_rx_queue_restock(priv);

}

EXPORT_SYMBOL(iwl_rx_replenish_now);





/* Assumes that the skb field of the buffers in 'pool' is kept accurate.

 * If an SKB has been detached, the POOL needs to have its SKB set to NULL
@@ -352,6 +363,7 @@ int iwl_rx_queue_alloc(struct iwl_priv *priv) 
	/* Set us so that we have processed and used all buffers, but have

	 * not restocked the Rx queue with fresh buffers */

	rxq->read = rxq->write = 0;

	rxq->write_actual = 0;

	rxq->free_count = 0;

	rxq->need_update = 0;

	return 0;
@@ -390,6 +402,7 @@ void iwl_rx_queue_reset(struct iwl_priv *priv, struct iwl_rx_queue *rxq) 
	/* Set us so that we have processed and used all buffers, but have

	 * not restocked the Rx queue with fresh buffers */

	rxq->read = rxq->write = 0;

	rxq->write_actual = 0;

	rxq->free_count = 0;

	spin_unlock_irqrestore(&rxq->lock, flags);

}

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