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>
diff --git a/drivers/net/wireless/iwlwifi/iwl-hcmd.c b/drivers/net/wireless/iwlwifi/iwl-hcmd.c
index 17d61ac..d8a3eac 100644
--- a/drivers/net/wireless/iwlwifi/iwl-hcmd.c
+++ b/drivers/net/wireless/iwlwifi/iwl-hcmd.c
@@ -104,7 +104,8 @@
 #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 @@
 {
 	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 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 @@
 
 	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 @@
 		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 @@
 	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 @@
 
 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 @@
 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 @@
 		.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);
 }