iwlwifi: don't pass iwl_rx_mem_buffer to upper layers

struct iwl_rx_mem_buffer implementation details
(DMA address, list pointers) that the upper
layers don't need. Introduce iwl_rx_cmd_buffer
that is passed upstream and only contains the
needed data (the page). Additionally, access
this data only via accessor functions, allowing
us to change the implementation in the future.
These accessors are rxb_addr() (as before) and
rxb_steal_page() to take ownership of the data.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 22 insertions, 19 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rx.c b/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
index bc21586..8e025e0 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
@@ -131,7 +131,7 @@ const char *get_cmd_string(u8 cmd)
  ******************************************************************************/
 
 static int iwlagn_rx_reply_error(struct iwl_priv *priv,
-			       struct iwl_rx_mem_buffer *rxb,
+			       struct iwl_rx_cmd_buffer *rxb,
 			       struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
@@ -146,7 +146,7 @@ static int iwlagn_rx_reply_error(struct iwl_priv *priv,
 	return 0;
 }
 
-static int iwlagn_rx_csa(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb,
+static int iwlagn_rx_csa(struct iwl_priv *priv, struct iwl_rx_cmd_buffer *rxb,
 			       struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
@@ -177,7 +177,7 @@ static int iwlagn_rx_csa(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb,
 
 
 static int iwlagn_rx_spectrum_measure_notif(struct iwl_priv *priv,
-					  struct iwl_rx_mem_buffer *rxb,
+					  struct iwl_rx_cmd_buffer *rxb,
 					  struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
@@ -195,7 +195,7 @@ static int iwlagn_rx_spectrum_measure_notif(struct iwl_priv *priv,
 }
 
 static int iwlagn_rx_pm_sleep_notif(struct iwl_priv *priv,
-				  struct iwl_rx_mem_buffer *rxb,
+				  struct iwl_rx_cmd_buffer *rxb,
 				  struct iwl_device_cmd *cmd)
 {
 #ifdef CONFIG_IWLWIFI_DEBUG
@@ -208,7 +208,7 @@ static int iwlagn_rx_pm_sleep_notif(struct iwl_priv *priv,
 }
 
 static int iwlagn_rx_pm_debug_statistics_notif(struct iwl_priv *priv,
-					     struct iwl_rx_mem_buffer *rxb,
+					     struct iwl_rx_cmd_buffer *rxb,
 					     struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
@@ -222,7 +222,7 @@ static int iwlagn_rx_pm_debug_statistics_notif(struct iwl_priv *priv,
 }
 
 static int iwlagn_rx_beacon_notif(struct iwl_priv *priv,
-				struct iwl_rx_mem_buffer *rxb,
+				struct iwl_rx_cmd_buffer *rxb,
 				struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
@@ -489,7 +489,7 @@ iwlagn_accumulative_statistics(struct iwl_priv *priv,
 #endif
 
 static int iwlagn_rx_statistics(struct iwl_priv *priv,
-			      struct iwl_rx_mem_buffer *rxb,
+			      struct iwl_rx_cmd_buffer *rxb,
 			      struct iwl_device_cmd *cmd)
 {
 	unsigned long stamp = jiffies;
@@ -597,7 +597,7 @@ static int iwlagn_rx_statistics(struct iwl_priv *priv,
 }
 
 static int iwlagn_rx_reply_statistics(struct iwl_priv *priv,
-				    struct iwl_rx_mem_buffer *rxb,
+				    struct iwl_rx_cmd_buffer *rxb,
 				    struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
@@ -620,7 +620,7 @@ static int iwlagn_rx_reply_statistics(struct iwl_priv *priv,
 /* Handle notification from uCode that card's power state is changing
  * due to software, hardware, or critical temperature RFKILL */
 static int iwlagn_rx_card_state_notif(struct iwl_priv *priv,
-				    struct iwl_rx_mem_buffer *rxb,
+				    struct iwl_rx_cmd_buffer *rxb,
 				    struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
@@ -673,7 +673,7 @@ static int iwlagn_rx_card_state_notif(struct iwl_priv *priv,
 }
 
 static int iwlagn_rx_missed_beacon_notif(struct iwl_priv *priv,
-				       struct iwl_rx_mem_buffer *rxb,
+				       struct iwl_rx_cmd_buffer *rxb,
 				       struct iwl_device_cmd *cmd)
 
 {
@@ -698,7 +698,7 @@ static int iwlagn_rx_missed_beacon_notif(struct iwl_priv *priv,
 /* Cache phy data (Rx signal strength, etc) for HT frame (REPLY_RX_PHY_CMD).
  * This will be used later in iwl_rx_reply_rx() for REPLY_RX_MPDU_CMD. */
 static int iwlagn_rx_reply_rx_phy(struct iwl_priv *priv,
-				struct iwl_rx_mem_buffer *rxb,
+				struct iwl_rx_cmd_buffer *rxb,
 				struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
@@ -765,12 +765,14 @@ static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv,
 					struct ieee80211_hdr *hdr,
 					u16 len,
 					u32 ampdu_status,
-					struct iwl_rx_mem_buffer *rxb,
+					struct iwl_rx_cmd_buffer *rxb,
 					struct ieee80211_rx_status *stats)
 {
 	struct sk_buff *skb;
 	__le16 fc = hdr->frame_control;
 	struct iwl_rxon_context *ctx;
+	struct page *p;
+	int offset;
 
 	/* We only process data packets if the interface is open */
 	if (unlikely(!priv->is_open)) {
@@ -790,7 +792,9 @@ static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv,
 		return;
 	}
 
-	skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len);
+	offset = (void *)hdr - rxb_addr(rxb);
+	p = rxb_steal_page(rxb);
+	skb_add_rx_frag(skb, 0, p, offset, len);
 
 	iwl_update_stats(priv, false, fc, len);
 
@@ -817,7 +821,6 @@ static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv,
 	memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
 
 	ieee80211_rx(priv->hw, skb);
-	rxb->page = NULL;
 }
 
 static u32 iwlagn_translate_rx_status(struct iwl_priv *priv, u32 decrypt_in)
@@ -923,7 +926,7 @@ static int iwlagn_calc_rssi(struct iwl_priv *priv,
 /* Called for REPLY_RX (legacy ABG frames), or
  * REPLY_RX_MPDU_CMD (HT high-throughput N frames). */
 static int iwlagn_rx_reply_rx(struct iwl_priv *priv,
-			    struct iwl_rx_mem_buffer *rxb,
+			    struct iwl_rx_cmd_buffer *rxb,
 			    struct iwl_device_cmd *cmd)
 {
 	struct ieee80211_hdr *header;
@@ -1043,7 +1046,7 @@ static int iwlagn_rx_reply_rx(struct iwl_priv *priv,
 }
 
 static int iwlagn_rx_noa_notification(struct iwl_priv *priv,
-				      struct iwl_rx_mem_buffer *rxb,
+				      struct iwl_rx_cmd_buffer *rxb,
 				      struct iwl_device_cmd *cmd)
 {
 	struct iwl_wipan_noa_data *new_data, *old_data;
@@ -1094,7 +1097,7 @@ static int iwlagn_rx_noa_notification(struct iwl_priv *priv,
  */
 void iwl_setup_rx_handlers(struct iwl_priv *priv)
 {
-	int (**handlers)(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb,
+	int (**handlers)(struct iwl_priv *priv, struct iwl_rx_cmd_buffer *rxb,
 			       struct iwl_device_cmd *cmd);
 
 	handlers = priv->rx_handlers;
@@ -1149,8 +1152,8 @@ void iwl_setup_rx_handlers(struct iwl_priv *priv)
 
 }
 
-int iwl_rx_dispatch(struct iwl_op_mode *op_mode, struct iwl_rx_mem_buffer *rxb,
-		     struct iwl_device_cmd *cmd)
+int iwl_rx_dispatch(struct iwl_op_mode *op_mode, struct iwl_rx_cmd_buffer *rxb,
+		    struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_priv *priv = IWL_OP_MODE_GET_DVM(op_mode);