iwlwifi: fix up command sending

The current command sending in iwlwifi is a bit of a mess:
 1) there is a struct, iwl_cmd, that contains both driver
    and device data in a single packed structure -- this
    is very confusing
 2) the on-stack data and the command metadata share a
    structure by embedding the latter in the former, which
    is also rather confusing because it leads to weird
    unions and similarly odd constructs
 3) each txq always has enough space for 256 commands,
    even if only 32 end up being used

This patch fixes these things:
 1) rename iwl_cmd to iwl_device_cmd and keep track of
    command metadata and device command separately, in
    two arrays in each tx queue
 2) remove the 'meta' member from iwl_host_cmd and only
    put in the required members
 3) allocate the cmd/meta arrays separately instead of
    embedding them into the txq structure

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-3945-led.c

@@ -80,7 +80,7 @@ static const struct {
 #define IWL_SOLID_BLINK_IDX (ARRAY_SIZE(blink_tbl) - 1)
 
 static int iwl3945_led_cmd_callback(struct iwl_priv *priv,
-				    struct iwl_cmd *cmd,
+				    struct iwl_device_cmd *cmd,
 				    struct sk_buff *skb)
 {
 	return 1;
@@ -99,8 +99,8 @@ static int iwl_send_led_cmd(struct iwl_priv *priv,
 		.id = REPLY_LEDS_CMD,
 		.len = sizeof(struct iwl_led_cmd),
 		.data = led_cmd,
-		.meta.flags = CMD_ASYNC,
-		.meta.u.callback = iwl3945_led_cmd_callback,
+		.flags = CMD_ASYNC,
+		.callback = iwl3945_led_cmd_callback,
 	};
 
 	return iwl_send_cmd(priv, &cmd);

drivers/net/wireless/iwlwifi/iwl-3945.c

@@ -749,8 +749,8 @@ void iwl3945_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
 	/* Unmap tx_cmd */
 	if (counter)
 		pci_unmap_single(dev,
-				pci_unmap_addr(&txq->cmd[index]->meta, mapping),
-				pci_unmap_len(&txq->cmd[index]->meta, len),
+				pci_unmap_addr(&txq->meta[index], mapping),
+				pci_unmap_len(&txq->meta[index], len),
 				PCI_DMA_TODEVICE);
 
 	/* unmap chunks if any */
@@ -774,9 +774,11 @@ void iwl3945_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
  * iwl3945_hw_build_tx_cmd_rate - Add rate portion to TX_CMD:
  *
 */
-void iwl3945_hw_build_tx_cmd_rate(struct iwl_priv *priv, struct iwl_cmd *cmd,
-			      struct ieee80211_tx_info *info,
-			      struct ieee80211_hdr *hdr, int sta_id, int tx_id)
+void iwl3945_hw_build_tx_cmd_rate(struct iwl_priv *priv,
+				  struct iwl_device_cmd *cmd,
+				  struct ieee80211_tx_info *info,
+				  struct ieee80211_hdr *hdr,
+				  int sta_id, int tx_id)
 {
 	u16 hw_value = ieee80211_get_tx_rate(priv->hw, info)->hw_value;
 	u16 rate_index = min(hw_value & 0xffff, IWL_RATE_COUNT - 1);
@@ -1858,7 +1860,7 @@ static int iwl3945_send_rxon_assoc(struct iwl_priv *priv)
 	struct iwl_host_cmd cmd = {
 		.id = REPLY_RXON_ASSOC,
 		.len = sizeof(rxon_assoc),
-		.meta.flags = CMD_WANT_SKB,
+		.flags = CMD_WANT_SKB,
 		.data = &rxon_assoc,
 	};
 	const struct iwl_rxon_cmd *rxon1 = &priv->staging_rxon;
@@ -1882,14 +1884,14 @@ static int iwl3945_send_rxon_assoc(struct iwl_priv *priv)
 	if (rc)
 		return rc;
 
-	res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
+	res = (struct iwl_rx_packet *)cmd.reply_skb->data;
 	if (res->hdr.flags & IWL_CMD_FAILED_MSK) {
 		IWL_ERR(priv, "Bad return from REPLY_RXON_ASSOC command\n");
 		rc = -EIO;
 	}
 
 	priv->alloc_rxb_skb--;
-	dev_kfree_skb_any(cmd.meta.u.skb);
+	dev_kfree_skb_any(cmd.reply_skb);
 
 	return rc;
 }

drivers/net/wireless/iwlwifi/iwl-3945.h

@@ -254,10 +254,11 @@ extern int iwl3945_hw_tx_queue_init(struct iwl_priv *priv,
 				struct iwl_tx_queue *txq);
 extern unsigned int iwl3945_hw_get_beacon_cmd(struct iwl_priv *priv,
 				 struct iwl3945_frame *frame, u8 rate);
-void iwl3945_hw_build_tx_cmd_rate(struct iwl_priv *priv, struct iwl_cmd *cmd,
-				     struct ieee80211_tx_info *info,
-				     struct ieee80211_hdr *hdr,
-				     int sta_id, int tx_id);
+void iwl3945_hw_build_tx_cmd_rate(struct iwl_priv *priv,
+				  struct iwl_device_cmd *cmd,
+				  struct ieee80211_tx_info *info,
+				  struct ieee80211_hdr *hdr,
+				  int sta_id, int tx_id);
 extern int iwl3945_hw_reg_send_txpower(struct iwl_priv *priv);
 extern int iwl3945_hw_reg_set_txpower(struct iwl_priv *priv, s8 power);
 extern void iwl3945_hw_rx_statistics(struct iwl_priv *priv,

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

@@ -442,8 +442,8 @@ void iwl_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
 	/* Unmap tx_cmd */
 	if (num_tbs)
 		pci_unmap_single(dev,
-				pci_unmap_addr(&txq->cmd[index]->meta, mapping),
-				pci_unmap_len(&txq->cmd[index]->meta, len),
+				pci_unmap_addr(&txq->meta[index], mapping),
+				pci_unmap_len(&txq->meta[index], len),
 				PCI_DMA_BIDIRECTIONAL);
 
 	/* Unmap chunks, if any. */

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

@@ -86,7 +86,7 @@ int iwl_send_calib_results(struct iwl_priv *priv)
 
 	struct iwl_host_cmd hcmd = {
 		.id = REPLY_PHY_CALIBRATION_CMD,
-		.meta.flags = CMD_SIZE_HUGE,
+		.flags = CMD_SIZE_HUGE,
 	};
 
 	for (i = 0; i < IWL_CALIB_MAX; i++) {
@@ -419,7 +419,7 @@ static int iwl_sensitivity_write(struct iwl_priv *priv)
 	struct iwl_host_cmd cmd_out = {
 		.id = SENSITIVITY_CMD,
 		.len = sizeof(struct iwl_sensitivity_cmd),
-		.meta.flags = CMD_ASYNC,
+		.flags = CMD_ASYNC,
 		.data = &cmd,
 	};
 

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

@@ -2089,7 +2089,7 @@ int iwl_send_statistics_request(struct iwl_priv *priv, u8 flags)
 	u32 stat_flags = 0;
 	struct iwl_host_cmd cmd = {
 		.id = REPLY_STATISTICS_CMD,
-		.meta.flags = flags,
+		.flags = flags,
 		.len = sizeof(stat_flags),
 		.data = (u8 *) &stat_flags,
 	};
@@ -2282,7 +2282,7 @@ int iwl_send_card_state(struct iwl_priv *priv, u32 flags, u8 meta_flag)
 		.id = REPLY_CARD_STATE_CMD,
 		.len = sizeof(u32),
 		.data = &flags,
-		.meta.flags = meta_flag,
+		.flags = meta_flag,
 	};
 
 	return iwl_send_cmd(priv, &cmd);

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

@@ -447,7 +447,7 @@ int __must_check iwl_send_cmd_pdu(struct iwl_priv *priv, u8 id,
 int iwl_send_cmd_pdu_async(struct iwl_priv *priv, u8 id, u16 len,
 			   const void *data,
 			   int (*callback)(struct iwl_priv *priv,
-					   struct iwl_cmd *cmd,
+					   struct iwl_device_cmd *cmd,
 					   struct sk_buff *skb));
 
 int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd);

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

@@ -150,6 +150,31 @@ struct iwl_rx_mem_buffer {
 	struct list_head list;
 };
 
+/* defined below */
+struct iwl_device_cmd;
+
+struct iwl_cmd_meta {
+	/* only for SYNC commands, iff the reply skb is wanted */
+	struct iwl_host_cmd *source;
+	/*
+	 * only for ASYNC commands
+	 * (which is somewhat stupid -- look at iwl-sta.c for instance
+	 * which duplicates a bunch of code because the callback isn't
+	 * invoked for SYNC commands, if it were and its result passed
+	 * through it would be simpler...)
+	 */
+	int (*callback)(struct iwl_priv *priv,
+			struct iwl_device_cmd *cmd,
+			struct sk_buff *skb);
+
+	/* The CMD_SIZE_HUGE flag bit indicates that the command
+	 * structure is stored at the end of the shared queue memory. */
+	u32 flags;
+
+	DECLARE_PCI_UNMAP_ADDR(mapping)
+	DECLARE_PCI_UNMAP_LEN(len)
+};
+
 /*
  * Generic queue structure
  *
@@ -177,7 +202,8 @@ struct iwl_tx_info {
  * struct iwl_tx_queue - Tx Queue for DMA
  * @q: generic Rx/Tx queue descriptor
  * @bd: base of circular buffer of TFDs
- * @cmd: array of command/Tx buffers
+ * @cmd: array of command/TX buffer pointers
+ * @meta: array of meta data for each command/tx buffer
  * @dma_addr_cmd: physical address of cmd/tx buffer array
  * @txb: array of per-TFD driver data
  * @need_update: indicates need to update read/write index
@@ -192,7 +218,8 @@ struct iwl_tx_info {
 struct iwl_tx_queue {
 	struct iwl_queue q;
 	void *tfds;
-	struct iwl_cmd *cmd[TFD_TX_CMD_SLOTS];
+	struct iwl_device_cmd **cmd;
+	struct iwl_cmd_meta *meta;
 	struct iwl_tx_info *txb;
 	u8 need_update;
 	u8 sched_retry;
@@ -329,35 +356,16 @@ enum {
 	CMD_WANT_SKB = (1 << 2),
 };
 
-struct iwl_cmd;
-struct iwl_priv;
-
-struct iwl_cmd_meta {
-	struct iwl_cmd_meta *source;
-	union {
-		struct sk_buff *skb;
-		int (*callback)(struct iwl_priv *priv,
-				struct iwl_cmd *cmd, struct sk_buff *skb);
-	} __attribute__ ((packed)) u;
-
-	/* The CMD_SIZE_HUGE flag bit indicates that the command
-	 * structure is stored at the end of the shared queue memory. */
-	u32 flags;
-	DECLARE_PCI_UNMAP_ADDR(mapping)
-	DECLARE_PCI_UNMAP_LEN(len)
-} __attribute__ ((packed));
-
 #define IWL_CMD_MAX_PAYLOAD 320
 
 /**
- * struct iwl_cmd
+ * struct iwl_device_cmd
  *
  * For allocation of the command and tx queues, this establishes the overall
  * size of the largest command we send to uCode, except for a scan command
  * (which is relatively huge; space is allocated separately).
  */
-struct iwl_cmd {
-	struct iwl_cmd_meta meta;	/* driver data */
+struct iwl_device_cmd {
 	struct iwl_cmd_header hdr;	/* uCode API */
 	union {
 		u32 flags;
@@ -369,17 +377,20 @@ struct iwl_cmd {
 	} __attribute__ ((packed)) cmd;
 } __attribute__ ((packed));
 
+#define TFD_MAX_PAYLOAD_SIZE (sizeof(struct iwl_device_cmd))
+
 
 struct iwl_host_cmd {
-	u8 id;
-	u16 len;
-	struct iwl_cmd_meta meta;
 	const void *data;
+	struct sk_buff *reply_skb;
+	int (*callback)(struct iwl_priv *priv,
+			struct iwl_device_cmd *cmd,
+			struct sk_buff *skb);
+	u32 flags;
+	u16 len;
+	u8 id;
 };
 
-#define TFD_MAX_PAYLOAD_SIZE (sizeof(struct iwl_cmd) - \
-			      sizeof(struct iwl_cmd_meta))
-
 /*
  * RX related structures and functions
  */

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

@@ -104,7 +104,8 @@ EXPORT_SYMBOL(get_cmd_string);
 #define HOST_COMPLETE_TIMEOUT (HZ / 2)
 
 static int iwl_generic_cmd_callback(struct iwl_priv *priv,
-				    struct iwl_cmd *cmd, struct sk_buff *skb)
+				    struct iwl_device_cmd *cmd,
+				    struct sk_buff *skb)
 {
 	struct iwl_rx_packet *pkt = NULL;
 
@@ -142,14 +143,14 @@ static int iwl_send_cmd_async(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
 {
 	int ret;
 
-	BUG_ON(!(cmd->meta.flags & CMD_ASYNC));
+	BUG_ON(!(cmd->flags & CMD_ASYNC));
 
 	/* An asynchronous command can not expect an SKB to be set. */
-	BUG_ON(cmd->meta.flags & CMD_WANT_SKB);
+	BUG_ON(cmd->flags & CMD_WANT_SKB);
 
 	/* Assign a generic callback if one is not provided */
-	if (!cmd->meta.u.callback)
-		cmd->meta.u.callback = iwl_generic_cmd_callback;
+	if (!cmd->callback)
+		cmd->callback = iwl_generic_cmd_callback;
 
 	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 		return -EBUSY;
@@ -168,10 +169,10 @@ int iwl_send_cmd_sync(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
 	int cmd_idx;
 	int ret;
 
-	BUG_ON(cmd->meta.flags & CMD_ASYNC);
+	BUG_ON(cmd->flags & CMD_ASYNC);
 
 	 /* A synchronous command can not have a callback set. */
-	BUG_ON(cmd->meta.u.callback != NULL);
+	BUG_ON(cmd->callback);
 
 	if (test_and_set_bit(STATUS_HCMD_SYNC_ACTIVE, &priv->status)) {
 		IWL_ERR(priv,
@@ -183,9 +184,6 @@ int iwl_send_cmd_sync(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
 
 	set_bit(STATUS_HCMD_ACTIVE, &priv->status);
 
-	if (cmd->meta.flags & CMD_WANT_SKB)
-		cmd->meta.source = &cmd->meta;
-
 	cmd_idx = iwl_enqueue_hcmd(priv, cmd);
 	if (cmd_idx < 0) {
 		ret = cmd_idx;
@@ -222,7 +220,7 @@ int iwl_send_cmd_sync(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
 		ret = -EIO;
 		goto fail;
 	}
-	if ((cmd->meta.flags & CMD_WANT_SKB) && !cmd->meta.u.skb) {
+	if ((cmd->flags & CMD_WANT_SKB) && !cmd->reply_skb) {
 		IWL_ERR(priv, "Error: Response NULL in '%s'\n",
 			  get_cmd_string(cmd->id));
 		ret = -EIO;
@@ -233,20 +231,20 @@ int iwl_send_cmd_sync(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
 	goto out;
 
 cancel:
-	if (cmd->meta.flags & CMD_WANT_SKB) {
-		struct iwl_cmd *qcmd;
-
-		/* Cancel the CMD_WANT_SKB flag for the cmd in the
+	if (cmd->flags & CMD_WANT_SKB) {
+		/*
+		 * Cancel the CMD_WANT_SKB flag for the cmd in the
 		 * TX cmd queue. Otherwise in case the cmd comes
 		 * in later, it will possibly set an invalid
-		 * address (cmd->meta.source). */
-		qcmd = priv->txq[IWL_CMD_QUEUE_NUM].cmd[cmd_idx];
-		qcmd->meta.flags &= ~CMD_WANT_SKB;
+		 * address (cmd->meta.source).
+		 */
+		priv->txq[IWL_CMD_QUEUE_NUM].meta[cmd_idx].flags &=
+							~CMD_WANT_SKB;
 	}
 fail:
-	if (cmd->meta.u.skb) {
-		dev_kfree_skb_any(cmd->meta.u.skb);
-		cmd->meta.u.skb = NULL;
+	if (cmd->reply_skb) {
+		dev_kfree_skb_any(cmd->reply_skb);
+		cmd->reply_skb = NULL;
 	}
 out:
 	clear_bit(STATUS_HCMD_SYNC_ACTIVE, &priv->status);
@@ -256,7 +254,7 @@ EXPORT_SYMBOL(iwl_send_cmd_sync);
 
 int iwl_send_cmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
 {
-	if (cmd->meta.flags & CMD_ASYNC)
+	if (cmd->flags & CMD_ASYNC)
 		return iwl_send_cmd_async(priv, cmd);
 
 	return iwl_send_cmd_sync(priv, cmd);
@@ -278,7 +276,7 @@ EXPORT_SYMBOL(iwl_send_cmd_pdu);
 int iwl_send_cmd_pdu_async(struct iwl_priv *priv,
 			   u8 id, u16 len, const void *data,
 			   int (*callback)(struct iwl_priv *priv,
-					   struct iwl_cmd *cmd,
+					   struct iwl_device_cmd *cmd,
 					   struct sk_buff *skb))
 {
 	struct iwl_host_cmd cmd = {
@@ -287,8 +285,8 @@ int iwl_send_cmd_pdu_async(struct iwl_priv *priv,
 		.data = data,
 	};
 
-	cmd.meta.flags |= CMD_ASYNC;
-	cmd.meta.u.callback = callback;
+	cmd.flags |= CMD_ASYNC;
+	cmd.callback = callback;
 
 	return iwl_send_cmd_async(priv, &cmd);
 }

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

@@ -91,8 +91,8 @@ static int iwl_send_led_cmd(struct iwl_priv *priv, struct iwl_led_cmd *led_cmd)
 		.id = REPLY_LEDS_CMD,
 		.len = sizeof(struct iwl_led_cmd),
 		.data = led_cmd,
-		.meta.flags = CMD_ASYNC,
-		.meta.u.callback = NULL,
+		.flags = CMD_ASYNC,
+		.callback = NULL,
 	};
 	u32 reg;