ath9k: use a separate data structure for rx buffers

There's no shared code for handling both rx and tx buffers, and tx
buffers require a lot more metadata than rx buffers.
Using a separate data structure for rx reduces memory usage and improves
cache footprint.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 92 insertions, 50 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 8878f2dada2d..83c045549db4 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -207,6 +207,14 @@ struct ath_frame_info {
         u8 baw_tracked : 1;
 };
 
+struct ath_rxbuf {
+        struct list_head list;
+        struct sk_buff *bf_mpdu;
+        void *bf_desc;
+        dma_addr_t bf_daddr;
+        dma_addr_t bf_buf_addr;
+};
+
 struct ath_buf_state {
         u8 bf_type;
         u8 bfs_paprd;
@@ -307,7 +315,7 @@ struct ath_rx {
         struct ath_descdma rxdma;
         struct ath_rx_edma rx_edma[ATH9K_RX_QUEUE_MAX];
 
-        struct ath_buf *buf_hold;
+        struct ath_rxbuf *buf_hold;
         struct sk_buff *frag;
 
         u32 ampdu_ref;
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index e3d11c41a145..2306f5788675 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -347,7 +347,6 @@ int ath_descdma_setup(struct ath_softc *sc, struct ath_descdma *dd,
 {
         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
         u8 *ds;
-        struct ath_buf *bf;
         int i, bsize, desc_len;
 
         ath_dbg(common, CONFIG, "%s DMA: %u buffers %u desc/buf\n",
@@ -399,33 +398,68 @@ int ath_descdma_setup(struct ath_softc *sc, struct ath_descdma *dd,
                 ito64(dd->dd_desc_paddr), /*XXX*/(u32) dd->dd_desc_len);
 
         /* allocate buffers */
-        bsize = sizeof(struct ath_buf) * nbuf;
-        bf = devm_kzalloc(sc->dev, bsize, GFP_KERNEL);
-        if (!bf)
-                return -ENOMEM;
+        if (is_tx) {
+                struct ath_buf *bf;
+
+                bsize = sizeof(struct ath_buf) * nbuf;
+                bf = devm_kzalloc(sc->dev, bsize, GFP_KERNEL);
+                if (!bf)
+                        return -ENOMEM;
+
+                for (i = 0; i < nbuf; i++, bf++, ds += (desc_len * ndesc)) {
+                        bf->bf_desc = ds;
+                        bf->bf_daddr = DS2PHYS(dd, ds);
+
+                        if (!(sc->sc_ah->caps.hw_caps &
+                                  ATH9K_HW_CAP_4KB_SPLITTRANS)) {
+                                /*
+                                 * Skip descriptor addresses which can cause 4KB
+                                 * boundary crossing (addr + length) with a 32 dword
+                                 * descriptor fetch.
+                                 */
+                                while (ATH_DESC_4KB_BOUND_CHECK(bf->bf_daddr)) {
+                                        BUG_ON((caddr_t) bf->bf_desc >=
+                                                   ((caddr_t) dd->dd_desc +
+                                                dd->dd_desc_len));
+
+                                        ds += (desc_len * ndesc);
+                                        bf->bf_desc = ds;
+                                        bf->bf_daddr = DS2PHYS(dd, ds);
+                                }
+                        }
+                        list_add_tail(&bf->list, head);
+                }
+        } else {
+                struct ath_rxbuf *bf;
+
+                bsize = sizeof(struct ath_rxbuf) * nbuf;
+                bf = devm_kzalloc(sc->dev, bsize, GFP_KERNEL);
+                if (!bf)
+                        return -ENOMEM;
 
-        for (i = 0; i < nbuf; i++, bf++, ds += (desc_len * ndesc)) {
-                bf->bf_desc = ds;
-                bf->bf_daddr = DS2PHYS(dd, ds);
-
-                if (!(sc->sc_ah->caps.hw_caps &
-                      ATH9K_HW_CAP_4KB_SPLITTRANS)) {
-                        /*
-                         * Skip descriptor addresses which can cause 4KB
-                         * boundary crossing (addr + length) with a 32 dword
-                         * descriptor fetch.
-                         */
-                        while (ATH_DESC_4KB_BOUND_CHECK(bf->bf_daddr)) {
-                                BUG_ON((caddr_t) bf->bf_desc >=
-                                       ((caddr_t) dd->dd_desc +
-                                        dd->dd_desc_len));
-
-                                ds += (desc_len * ndesc);
-                                bf->bf_desc = ds;
-                                bf->bf_daddr = DS2PHYS(dd, ds);
+                for (i = 0; i < nbuf; i++, bf++, ds += (desc_len * ndesc)) {
+                        bf->bf_desc = ds;
+                        bf->bf_daddr = DS2PHYS(dd, ds);
+
+                        if (!(sc->sc_ah->caps.hw_caps &
+                                  ATH9K_HW_CAP_4KB_SPLITTRANS)) {
+                                /*
+                                 * Skip descriptor addresses which can cause 4KB
+                                 * boundary crossing (addr + length) with a 32 dword
+                                 * descriptor fetch.
+                                 */
+                                while (ATH_DESC_4KB_BOUND_CHECK(bf->bf_daddr)) {
+                                        BUG_ON((caddr_t) bf->bf_desc >=
+                                                   ((caddr_t) dd->dd_desc +
+                                                dd->dd_desc_len));
+
+                                        ds += (desc_len * ndesc);
+                                        bf->bf_desc = ds;
+                                        bf->bf_daddr = DS2PHYS(dd, ds);
+                                }
                         }
+                        list_add_tail(&bf->list, head);
                 }
-                list_add_tail(&bf->list, head);
         }
         return 0;
 }
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 4ee472a5a4e4..a05164166de8 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -19,7 +19,7 @@
 #include "ath9k.h"
 #include "ar9003_mac.h"
 
-#define SKB_CB_ATHBUF(__skb)    (*((struct ath_buf **)__skb->cb))
+#define SKB_CB_ATHBUF(__skb)    (*((struct ath_rxbuf **)__skb->cb))
 
 static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
 {
@@ -35,7 +35,7 @@ static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
  * buffer (or rx fifo). This can incorrectly acknowledge packets
  * to a sender if last desc is self-linked.
  */
-static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
+static void ath_rx_buf_link(struct ath_softc *sc, struct ath_rxbuf *bf)
 {
         struct ath_hw *ah = sc->sc_ah;
         struct ath_common *common = ath9k_hw_common(ah);
@@ -68,7 +68,7 @@ static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
         sc->rx.rxlink = &ds->ds_link;
 }
 
-static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_buf *bf)
+static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_rxbuf *bf)
 {
         if (sc->rx.buf_hold)
                 ath_rx_buf_link(sc, sc->rx.buf_hold);
@@ -112,13 +112,13 @@ static bool ath_rx_edma_buf_link(struct ath_softc *sc,
         struct ath_hw *ah = sc->sc_ah;
         struct ath_rx_edma *rx_edma;
         struct sk_buff *skb;
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
 
         rx_edma = &sc->rx.rx_edma[qtype];
         if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
                 return false;
 
-        bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
+        bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
         list_del_init(&bf->list);
 
         skb = bf->bf_mpdu;
@@ -138,7 +138,7 @@ static void ath_rx_addbuffer_edma(struct ath_softc *sc,
                                   enum ath9k_rx_qtype qtype)
 {
         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
-        struct ath_buf *bf, *tbf;
+        struct ath_rxbuf *bf, *tbf;
 
         if (list_empty(&sc->rx.rxbuf)) {
                 ath_dbg(common, QUEUE, "No free rx buf available\n");
@@ -154,7 +154,7 @@ static void ath_rx_addbuffer_edma(struct ath_softc *sc,
 static void ath_rx_remove_buffer(struct ath_softc *sc,
                                  enum ath9k_rx_qtype qtype)
 {
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
         struct ath_rx_edma *rx_edma;
         struct sk_buff *skb;
 
@@ -171,7 +171,7 @@ static void ath_rx_edma_cleanup(struct ath_softc *sc)
 {
         struct ath_hw *ah = sc->sc_ah;
         struct ath_common *common = ath9k_hw_common(ah);
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
 
         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
@@ -199,7 +199,7 @@ static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
         struct ath_hw *ah = sc->sc_ah;
         struct sk_buff *skb;
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
         int error = 0, i;
         u32 size;
 
@@ -211,7 +211,7 @@ static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
                                ah->caps.rx_hp_qdepth);
 
-        size = sizeof(struct ath_buf) * nbufs;
+        size = sizeof(struct ath_rxbuf) * nbufs;
         bf = devm_kzalloc(sc->dev, size, GFP_KERNEL);
         if (!bf)
                 return -ENOMEM;
@@ -271,7 +271,7 @@ int ath_rx_init(struct ath_softc *sc, int nbufs)
 {
         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
         struct sk_buff *skb;
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
         int error = 0;
 
         spin_lock_init(&sc->sc_pcu_lock);
@@ -332,7 +332,7 @@ void ath_rx_cleanup(struct ath_softc *sc)
         struct ath_hw *ah = sc->sc_ah;
         struct ath_common *common = ath9k_hw_common(ah);
         struct sk_buff *skb;
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
 
         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
                 ath_rx_edma_cleanup(sc);
@@ -427,7 +427,7 @@ u32 ath_calcrxfilter(struct ath_softc *sc)
 int ath_startrecv(struct ath_softc *sc)
 {
         struct ath_hw *ah = sc->sc_ah;
-        struct ath_buf *bf, *tbf;
+        struct ath_rxbuf *bf, *tbf;
 
         if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
                 ath_edma_start_recv(sc);
@@ -447,7 +447,7 @@ int ath_startrecv(struct ath_softc *sc)
         if (list_empty(&sc->rx.rxbuf))
                 goto start_recv;
 
-        bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
+        bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
         ath9k_hw_putrxbuf(ah, bf->bf_daddr);
         ath9k_hw_rxena(ah);
 
@@ -603,13 +603,13 @@ static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb, bool mybeacon)
 static bool ath_edma_get_buffers(struct ath_softc *sc,
                                  enum ath9k_rx_qtype qtype,
                                  struct ath_rx_status *rs,
-                                 struct ath_buf **dest)
+                                 struct ath_rxbuf **dest)
 {
         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
         struct ath_hw *ah = sc->sc_ah;
         struct ath_common *common = ath9k_hw_common(ah);
         struct sk_buff *skb;
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
         int ret;
 
         skb = skb_peek(&rx_edma->rx_fifo);
@@ -653,11 +653,11 @@ static bool ath_edma_get_buffers(struct ath_softc *sc,
         return true;
 }
 
-static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
+static struct ath_rxbuf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
                                                 struct ath_rx_status *rs,
                                                 enum ath9k_rx_qtype qtype)
 {
-        struct ath_buf *bf = NULL;
+        struct ath_rxbuf *bf = NULL;
 
         while (ath_edma_get_buffers(sc, qtype, rs, &bf)) {
                 if (!bf)
@@ -668,13 +668,13 @@ static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
         return NULL;
 }
 
-static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
+static struct ath_rxbuf *ath_get_next_rx_buf(struct ath_softc *sc,
                                            struct ath_rx_status *rs)
 {
         struct ath_hw *ah = sc->sc_ah;
         struct ath_common *common = ath9k_hw_common(ah);
         struct ath_desc *ds;
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
         int ret;
 
         if (list_empty(&sc->rx.rxbuf)) {
@@ -682,7 +682,7 @@ static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
                 return NULL;
         }
 
-        bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
+        bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
         if (bf == sc->rx.buf_hold)
                 return NULL;
 
@@ -702,7 +702,7 @@ static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
         ret = ath9k_hw_rxprocdesc(ah, ds, rs);
         if (ret == -EINPROGRESS) {
                 struct ath_rx_status trs;
-                struct ath_buf *tbf;
+                struct ath_rxbuf *tbf;
                 struct ath_desc *tds;
 
                 memset(&trs, 0, sizeof(trs));
@@ -711,7 +711,7 @@ static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
                         return NULL;
                 }
 
-                tbf = list_entry(bf->list.next, struct ath_buf, list);
+                tbf = list_entry(bf->list.next, struct ath_rxbuf, list);
 
                 /*
                  * On some hardware the descriptor status words could
@@ -1315,7 +1315,7 @@ static void ath9k_apply_ampdu_details(struct ath_softc *sc,
 
 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 {
-        struct ath_buf *bf;
+        struct ath_rxbuf *bf;
         struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
         struct ieee80211_rx_status *rxs;
         struct ath_hw *ah = sc->sc_ah;