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>

1 files changed, 40 insertions, 29 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index cddf17350c4..ce765f79275 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/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
  */