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: Mohamed Abbas <mohamed.abbas@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 19 insertions, 6 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index 7a432829e79f..c845089701eb 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -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);
 }