brcmsmac: Use IEEE 802.11 AC levels for pktq precedence levels

The mac80211 tx queues and brcmsmac DMA fifos both map directly to AC
levels. Therefore it's much more straightforward to queue tx frames and
choose the tx fifo based on the mac80211 queue instead of mapping 802.1D
priority tags to precedence levels then back to AC levels. mac80211
already maps the 802.1D levels to the appropriate AC levels and queues
management frames at the maximum priority, so the results should be
identical.

One functional change resulting from this patch is that AMPDU retries no
longer get a priority boost to queue them ahead of packets with the same
priority already in the tx queue. This behavior will be restored (in
effect at least) in a later patch when the tx queue is removed.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Tested-by: Daniel Wagner <wagi@monom.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 22 insertions, 45 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmsmac/main.c b/drivers/net/wireless/brcm80211/brcmsmac/main.c
index 7563d46..eebbe30 100644
--- a/drivers/net/wireless/brcm80211/brcmsmac/main.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/main.c
@@ -277,17 +277,6 @@ struct edcf_acparam {
 	u16 TXOP;
 } __packed;
 
-const u8 prio2fifo[NUMPRIO] = {
-	TX_AC_BE_FIFO,		/* 0    BE      AC_BE   Best Effort */
-	TX_AC_BK_FIFO,		/* 1    BK      AC_BK   Background */
-	TX_AC_BK_FIFO,		/* 2    --      AC_BK   Background */
-	TX_AC_BE_FIFO,		/* 3    EE      AC_BE   Best Effort */
-	TX_AC_VI_FIFO,		/* 4    CL      AC_VI   Video */
-	TX_AC_VI_FIFO,		/* 5    VI      AC_VI   Video */
-	TX_AC_VO_FIFO,		/* 6    VO      AC_VO   Voice */
-	TX_AC_VO_FIFO		/* 7    NC      AC_VO   Voice */
-};
-
 /* debug/trace */
 uint brcm_msg_level =
 #if defined(DEBUG)
@@ -314,18 +303,6 @@ static const u8 wme_ac2fifo[] = {
 	TX_AC_BK_FIFO
 };
 
-/* 802.1D Priority to precedence queue mapping */
-const u8 wlc_prio2prec_map[] = {
-	_BRCMS_PREC_BE,		/* 0 BE - Best-effort */
-	_BRCMS_PREC_BK,		/* 1 BK - Background */
-	_BRCMS_PREC_NONE,		/* 2 None = - */
-	_BRCMS_PREC_EE,		/* 3 EE - Excellent-effort */
-	_BRCMS_PREC_CL,		/* 4 CL - Controlled Load */
-	_BRCMS_PREC_VI,		/* 5 Vi - Video */
-	_BRCMS_PREC_VO,		/* 6 Vo - Voice */
-	_BRCMS_PREC_NC,		/* 7 NC - Network Control */
-};
-
 static const u16 xmtfifo_sz[][NFIFO] = {
 	/* corerev 17: 5120, 49152, 49152, 5376, 4352, 1280 */
 	{20, 192, 192, 21, 17, 5},
@@ -365,6 +342,21 @@ static const char fifo_names[6][0];
 static struct brcms_c_info *wlc_info_dbg = (struct brcms_c_info *) (NULL);
 #endif
 
+/* Mapping of ieee80211 AC numbers to tx fifos */
+static const u8 ac_to_fifo_mapping[IEEE80211_NUM_ACS] = {
+	[IEEE80211_AC_VO]	= TX_AC_VO_FIFO,
+	[IEEE80211_AC_VI]	= TX_AC_VI_FIFO,
+	[IEEE80211_AC_BE]	= TX_AC_BE_FIFO,
+	[IEEE80211_AC_BK]	= TX_AC_BK_FIFO,
+};
+
+static u8 brcms_ac_to_fifo(u8 ac)
+{
+	if (ac >= ARRAY_SIZE(ac_to_fifo_mapping))
+		return TX_AC_BE_FIFO;
+	return ac_to_fifo_mapping[ac];
+}
+
 /* Find basic rate for a given rate */
 static u8 brcms_basic_rate(struct brcms_c_info *wlc, u32 rspec)
 {
@@ -3753,12 +3745,6 @@ brcms_c_duty_cycle_set(struct brcms_c_info *wlc, int duty_cycle, bool isOFDM,
 static void brcms_c_tx_prec_map_init(struct brcms_c_info *wlc)
 {
 	wlc->tx_prec_map = BRCMS_PREC_BMP_ALL;
-	memset(wlc->fifo2prec_map, 0, NFIFO * sizeof(u16));
-
-	wlc->fifo2prec_map[TX_AC_BK_FIFO] = BRCMS_PREC_BMP_AC_BK;
-	wlc->fifo2prec_map[TX_AC_BE_FIFO] = BRCMS_PREC_BMP_AC_BE;
-	wlc->fifo2prec_map[TX_AC_VI_FIFO] = BRCMS_PREC_BMP_AC_VI;
-	wlc->fifo2prec_map[TX_AC_VO_FIFO] = BRCMS_PREC_BMP_AC_VO;
 }
 
 /* push sw hps and wake state through hardware */
@@ -6068,14 +6054,13 @@ static bool brcms_c_prec_enq(struct brcms_c_info *wlc, struct pktq *q,
 }
 
 void brcms_c_txq_enq(struct brcms_c_info *wlc, struct scb *scb,
-		     struct sk_buff *sdu, uint prec)
+		     struct sk_buff *sdu)
 {
 	struct brcms_txq_info *qi = wlc->pkt_queue;	/* Check me */
 	struct pktq *q = &qi->q;
-	int prio;
-
-	prio = sdu->priority;
+	uint prec;
 
+	prec = brcms_ac_to_fifo(skb_get_queue_mapping(sdu));
 	if (!brcms_c_prec_enq(wlc, q, sdu, prec)) {
 		/*
 		 * we might hit this condtion in case
@@ -7248,21 +7233,13 @@ brcms_c_d11hdrs_mac80211(struct brcms_c_info *wlc, struct ieee80211_hw *hw,
 void brcms_c_sendpkt_mac80211(struct brcms_c_info *wlc, struct sk_buff *sdu,
 			      struct ieee80211_hw *hw)
 {
-	u8 prio;
 	uint fifo;
 	struct scb *scb = &wlc->pri_scb;
-	struct ieee80211_hdr *d11_header = (struct ieee80211_hdr *)(sdu->data);
 
-	/*
-	 * 802.11 standard requires management traffic
-	 * to go at highest priority
-	 */
-	prio = ieee80211_is_data(d11_header->frame_control) ? sdu->priority :
-		MAXPRIO;
-	fifo = prio2fifo[prio];
+	fifo = brcms_ac_to_fifo(skb_get_queue_mapping(sdu));
 	if (brcms_c_d11hdrs_mac80211(wlc, hw, sdu, scb, 0, 1, fifo, 0))
 		return;
-	brcms_c_txq_enq(wlc, scb, sdu, BRCMS_PRIO_TO_PREC(prio));
+	brcms_c_txq_enq(wlc, scb, sdu);
 	brcms_c_send_q(wlc);
 }
 
@@ -7402,7 +7379,7 @@ brcms_c_txfifo_complete(struct brcms_c_info *wlc, uint fifo)
 	       wlc->core->txpktpend[fifo]);
 
 	/* There is more room; mark precedences related to this FIFO sendable */
-	wlc->tx_prec_map |= wlc->fifo2prec_map[fifo];
+	wlc->tx_prec_map |= 1 << fifo;
 
 	/* figure out which bsscfg is being worked on... */
 }
@@ -7877,7 +7854,7 @@ int brcms_c_prep_pdu(struct brcms_c_info *wlc, struct sk_buff *pdu, uint *fifop)
 	if (*wlc->core->txavail[fifo] < MAX_DMA_SEGS) {
 		/* Mark precedences related to this FIFO, unsendable */
 		/* A fifo is full. Clear precedences related to that FIFO */
-		wlc->tx_prec_map &= ~(wlc->fifo2prec_map[fifo]);
+		wlc->tx_prec_map &= ~(1 << fifo);
 		return -EBUSY;
 	}
 	return 0;