ath9k_common: add new module to share 802.11n driver helpers

ath9k and ath9k_htc share a lot of common hardware characteristics.
They only differ in that ath9k_htc works with a target CPU and ath9k
works directly with the hardware. ath9k_htc will do *some* things in
the firmware, but a lot of others on the host.

The common 802.11n hardware code is already shared through the ath9k_hw
module. Common helpers amongst all Atheros drivers can use the ath module,
this includes ath5k and ar9170 as users. But there is some common driver
specific helpers which are not exactly hardware code which ath9k and
ath9k_htc can share. We'll be using ath9k_common for this to avoid
bloating the ath module and the common 802.11n hardware module ath9k_hw.

We start by sharing skb pre and post processing in preparation for a hand
off to mac80211.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/Kconfig

@@ -1,5 +1,7 @@
 config ATH9K_HW
 	tristate
+config ATH9K_COMMON
+	tristate
 
 config ATH9K
 	tristate "Atheros 802.11n wireless cards support"
@@ -8,6 +10,7 @@ config ATH9K
 	select MAC80211_LEDS
 	select LEDS_CLASS
 	select NEW_LEDS
+	select ATH9K_COMMON
 	---help---
 	  This module adds support for wireless adapters based on
 	  Atheros IEEE 802.11n AR5008, AR9001 and AR9002 family

drivers/net/wireless/ath/ath9k/Makefile

@@ -23,3 +23,6 @@ ath9k_hw-y:=	hw.o \
 		mac.o \
 
 obj-$(CONFIG_ATH9K_HW) += ath9k_hw.o
+
+obj-$(CONFIG_ATH9K_COMMON) += ath9k_common.o
+ath9k_common-y:=	common.o

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -19,14 +19,16 @@
 
 #include <linux/etherdevice.h>
 #include <linux/device.h>
-#include <net/mac80211.h>
 #include <linux/leds.h>
 
-#include "hw.h"
 #include "rc.h"
 #include "debug.h"
-#include "../ath.h"
-#include "../debug.h"
+#include "common.h"
+
+/*
+ * Header for the ath9k.ko driver core *only* -- hw code nor any other driver
+ * should rely on this file or its contents.
+ */
 
 struct ath_node;
 
@@ -99,18 +101,6 @@ enum buffer_type {
 	BUF_XRETRY		= BIT(5),
 };
 
-struct ath_buf_state {
-	int bfs_nframes;
-	u16 bfs_al;
-	u16 bfs_frmlen;
-	int bfs_seqno;
-	int bfs_tidno;
-	int bfs_retries;
-	u8 bf_type;
-	u32 bfs_keyix;
-	enum ath9k_key_type bfs_keytype;
-};
-
 #define bf_nframes      	bf_state.bfs_nframes
 #define bf_al           	bf_state.bfs_al
 #define bf_frmlen       	bf_state.bfs_frmlen
@@ -125,21 +115,6 @@ struct ath_buf_state {
 #define bf_isretried(bf)	(bf->bf_state.bf_type & BUF_RETRY)
 #define bf_isxretried(bf)	(bf->bf_state.bf_type & BUF_XRETRY)
 
-struct ath_buf {
-	struct list_head list;
-	struct ath_buf *bf_lastbf;	/* last buf of this unit (a frame or
-					   an aggregate) */
-	struct ath_buf *bf_next;	/* next subframe in the aggregate */
-	struct sk_buff *bf_mpdu;	/* enclosing frame structure */
-	struct ath_desc *bf_desc;	/* virtual addr of desc */
-	dma_addr_t bf_daddr;		/* physical addr of desc */
-	dma_addr_t bf_buf_addr;		/* physical addr of data buffer */
-	bool bf_stale;
-	u16 bf_flags;
-	struct ath_buf_state bf_state;
-	dma_addr_t bf_dmacontext;
-};
-
 struct ath_descdma {
 	struct ath_desc *dd_desc;
 	dma_addr_t dd_desc_paddr;
@@ -159,26 +134,16 @@ void ath_descdma_cleanup(struct ath_softc *sc, struct ath_descdma *dd,
 
 #define ATH_MAX_ANTENNA         3
 #define ATH_RXBUF               512
-#define WME_NUM_TID             16
 #define ATH_TXBUF               512
 #define ATH_TXMAXTRY            13
 #define ATH_MGT_TXMAXTRY        4
-#define WME_BA_BMP_SIZE         64
-#define WME_MAX_BA              WME_BA_BMP_SIZE
-#define ATH_TID_MAX_BUFS        (2 * WME_MAX_BA)
 
 #define TID_TO_WME_AC(_tid)				\
 	((((_tid) == 0) || ((_tid) == 3)) ? WME_AC_BE :	\
 	 (((_tid) == 1) || ((_tid) == 2)) ? WME_AC_BK :	\
 	 (((_tid) == 4) || ((_tid) == 5)) ? WME_AC_VI :	\
 	 WME_AC_VO)
 
-#define WME_AC_BE   0
-#define WME_AC_BK   1
-#define WME_AC_VI   2
-#define WME_AC_VO   3
-#define WME_NUM_AC  4
-
 #define ADDBA_EXCHANGE_ATTEMPTS    10
 #define ATH_AGGR_DELIM_SZ          4
 #define ATH_AGGR_MINPLEN           256 /* in bytes, minimum packet length */
@@ -252,30 +217,6 @@ struct ath_txq {
 #define AGGR_ADDBA_COMPLETE  BIT(2)
 #define AGGR_ADDBA_PROGRESS  BIT(3)
 
-struct ath_atx_tid {
-	struct list_head list;
-	struct list_head buf_q;
-	struct ath_node *an;
-	struct ath_atx_ac *ac;
-	struct ath_buf *tx_buf[ATH_TID_MAX_BUFS];
-	u16 seq_start;
-	u16 seq_next;
-	u16 baw_size;
-	int tidno;
-	int baw_head;	/* first un-acked tx buffer */
-	int baw_tail;	/* next unused tx buffer slot */
-	int sched;
-	int paused;
-	u8 state;
-};
-
-struct ath_atx_ac {
-	int sched;
-	int qnum;
-	struct list_head list;
-	struct list_head tid_q;
-};
-
 struct ath_tx_control {
 	struct ath_txq *txq;
 	int if_id;
@@ -286,29 +227,6 @@ struct ath_tx_control {
 #define ATH_TX_XRETRY       0x02
 #define ATH_TX_BAR          0x04
 
-#define ATH_RSSI_LPF_LEN 		10
-#define RSSI_LPF_THRESHOLD		-20
-#define ATH_RSSI_EP_MULTIPLIER     (1<<7)
-#define ATH_EP_MUL(x, mul)         ((x) * (mul))
-#define ATH_RSSI_IN(x)             (ATH_EP_MUL((x), ATH_RSSI_EP_MULTIPLIER))
-#define ATH_LPF_RSSI(x, y, len) \
-    ((x != ATH_RSSI_DUMMY_MARKER) ? (((x) * ((len) - 1) + (y)) / (len)) : (y))
-#define ATH_RSSI_LPF(x, y) do {                     			\
-    if ((y) >= RSSI_LPF_THRESHOLD)                         		\
-	x = ATH_LPF_RSSI((x), ATH_RSSI_IN((y)), ATH_RSSI_LPF_LEN);  	\
-} while (0)
-#define ATH_EP_RND(x, mul) 						\
-	((((x)%(mul)) >= ((mul)/2)) ? ((x) + ((mul) - 1)) / (mul) : (x)/(mul))
-
-struct ath_node {
-	struct ath_softc *an_sc;
-	struct ath_atx_tid tid[WME_NUM_TID];
-	struct ath_atx_ac ac[WME_NUM_AC];
-	u16 maxampdu;
-	u8 mpdudensity;
-	int last_rssi;
-};
-
 struct ath_tx {
 	u16 seq_no;
 	u32 txqsetup;
@@ -493,7 +411,6 @@ struct ath_led {
 #define IEEE80211_WEP_NKID      4       /* number of key ids */
 
 #define ATH_TXPOWER_MAX         100     /* .5 dBm units */
-#define ATH_RSSI_DUMMY_MARKER   0x127
 #define ATH_RATE_DUMMY_MARKER   0
 
 #define SC_OP_INVALID           BIT(0)