b43: Optimize PIO scratchbuffer usage

This optimizes the PIO scratchbuffer usage.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 51 insertions, 46 deletions

diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index 660716214d49..65b23f725a04 100644
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -749,12 +749,6 @@ struct b43_wldev {
 #endif
 };
 
-/*
- * Include goes here to avoid a dependency problem.
- * A better fix would be to integrate xmit.h into b43.h.
- */
-#include "xmit.h"
-
 /* Data structure for the WLAN parts (802.11 cores) of the b43 chip. */
 struct b43_wl {
         /* Pointer to the active wireless device on this chip */
@@ -830,13 +824,9 @@ struct b43_wl {
         struct b43_leds leds;
 
 #ifdef CONFIG_B43_PIO
-        /*
-         * RX/TX header/tail buffers used by the frame transmit functions.
-         */
-        struct b43_rxhdr_fw4 rxhdr;
-        struct b43_txhdr txhdr;
-        u8 rx_tail[4];
-        u8 tx_tail[4];
+        /* Kmalloc'ed scratch space for PIO TX/RX. Protected by wl->mutex. */
+        u8 pio_scratchspace[110] __attribute__((__aligned__(8)));
+        u8 pio_tailspace[4] __attribute__((__aligned__(8)));
 #endif /* CONFIG_B43_PIO */
 };
 
diff --git a/drivers/net/wireless/b43/pio.c b/drivers/net/wireless/b43/pio.c
index dbbf0d11e18e..3105f235303a 100644
--- a/drivers/net/wireless/b43/pio.c
+++ b/drivers/net/wireless/b43/pio.c
@@ -341,12 +341,15 @@ static u16 tx_write_2byte_queue(struct b43_pio_txqueue *q,
                         q->mmio_base + B43_PIO_TXDATA,
                         sizeof(u16));
         if (data_len & 1) {
+                u8 *tail = wl->pio_tailspace;
+                BUILD_BUG_ON(sizeof(wl->pio_tailspace) < 2);
+
                 /* Write the last byte. */
                 ctl &= ~B43_PIO_TXCTL_WRITEHI;
                 b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
-                wl->tx_tail[0] = data[data_len - 1];
-                wl->tx_tail[1] = 0;
-                ssb_block_write(dev->dev, wl->tx_tail, 2,
+                tail[0] = data[data_len - 1];
+                tail[1] = 0;
+                ssb_block_write(dev->dev, tail, 2,
                                 q->mmio_base + B43_PIO_TXDATA,
                                 sizeof(u16));
         }
@@ -392,31 +395,31 @@ static u32 tx_write_4byte_queue(struct b43_pio_txqueue *q,
                         q->mmio_base + B43_PIO8_TXDATA,
                         sizeof(u32));
         if (data_len & 3) {
-                wl->tx_tail[3] = 0;
+                u8 *tail = wl->pio_tailspace;
+                BUILD_BUG_ON(sizeof(wl->pio_tailspace) < 4);
+
+                memset(tail, 0, 4);
                 /* Write the last few bytes. */
                 ctl &= ~(B43_PIO8_TXCTL_8_15 | B43_PIO8_TXCTL_16_23 |
                          B43_PIO8_TXCTL_24_31);
                 switch (data_len & 3) {
                 case 3:
                         ctl |= B43_PIO8_TXCTL_16_23 | B43_PIO8_TXCTL_8_15;
-                        wl->tx_tail[0] = data[data_len - 3];
-                        wl->tx_tail[1] = data[data_len - 2];
-                        wl->tx_tail[2] = data[data_len - 1];
+                        tail[0] = data[data_len - 3];
+                        tail[1] = data[data_len - 2];
+                        tail[2] = data[data_len - 1];
                         break;
                 case 2:
                         ctl |= B43_PIO8_TXCTL_8_15;
-                        wl->tx_tail[0] = data[data_len - 2];
-                        wl->tx_tail[1] = data[data_len - 1];
-                        wl->tx_tail[2] = 0;
+                        tail[0] = data[data_len - 2];
+                        tail[1] = data[data_len - 1];
                         break;
                 case 1:
-                        wl->tx_tail[0] = data[data_len - 1];
-                        wl->tx_tail[1] = 0;
-                        wl->tx_tail[2] = 0;
+                        tail[0] = data[data_len - 1];
                         break;
                 }
                 b43_piotx_write32(q, B43_PIO8_TXCTL, ctl);
-                ssb_block_write(dev->dev, wl->tx_tail, 4,
+                ssb_block_write(dev->dev, tail, 4,
                                 q->mmio_base + B43_PIO8_TXDATA,
                                 sizeof(u32));
         }
@@ -455,6 +458,7 @@ static int pio_tx_frame(struct b43_pio_txqueue *q,
         int err;
         unsigned int hdrlen;
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+        struct b43_txhdr *txhdr = (struct b43_txhdr *)wl->pio_scratchspace;
 
         B43_WARN_ON(list_empty(&q->packets_list));
         pack = list_entry(q->packets_list.next,
@@ -462,7 +466,9 @@ static int pio_tx_frame(struct b43_pio_txqueue *q,
 
         cookie = generate_cookie(q, pack);
         hdrlen = b43_txhdr_size(dev);
-        err = b43_generate_txhdr(dev, (u8 *)&wl->txhdr, skb,
+        BUILD_BUG_ON(sizeof(wl->pio_scratchspace) < sizeof(struct b43_txhdr));
+        B43_WARN_ON(sizeof(wl->pio_scratchspace) < hdrlen);
+        err = b43_generate_txhdr(dev, (u8 *)txhdr, skb,
                                  info, cookie);
         if (err)
                 return err;
@@ -476,9 +482,9 @@ static int pio_tx_frame(struct b43_pio_txqueue *q,
 
         pack->skb = skb;
         if (q->rev >= 8)
-                pio_tx_frame_4byte_queue(pack, (const u8 *)&wl->txhdr, hdrlen);
+                pio_tx_frame_4byte_queue(pack, (const u8 *)txhdr, hdrlen);
         else
-                pio_tx_frame_2byte_queue(pack, (const u8 *)&wl->txhdr, hdrlen);
+                pio_tx_frame_2byte_queue(pack, (const u8 *)txhdr, hdrlen);
 
         /* Remove it from the list of available packet slots.
          * It will be put back when we receive the status report. */
@@ -624,8 +630,11 @@ static bool pio_rx_frame(struct b43_pio_rxqueue *q)
         unsigned int i, padding;
         struct sk_buff *skb;
         const char *err_msg = NULL;
+        struct b43_rxhdr_fw4 *rxhdr =
+                (struct b43_rxhdr_fw4 *)wl->pio_scratchspace;
 
-        memset(&wl->rxhdr, 0, sizeof(wl->rxhdr));
+        BUILD_BUG_ON(sizeof(wl->pio_scratchspace) < sizeof(*rxhdr));
+        memset(rxhdr, 0, sizeof(*rxhdr));
 
         /* Check if we have data and wait for it to get ready. */
         if (q->rev >= 8) {
@@ -663,16 +672,16 @@ data_ready:
 
         /* Get the preamble (RX header) */
         if (q->rev >= 8) {
-                ssb_block_read(dev->dev, &wl->rxhdr, sizeof(wl->rxhdr),
+                ssb_block_read(dev->dev, rxhdr, sizeof(*rxhdr),
                                q->mmio_base + B43_PIO8_RXDATA,
                                sizeof(u32));
         } else {
-                ssb_block_read(dev->dev, &wl->rxhdr, sizeof(wl->rxhdr),
+                ssb_block_read(dev->dev, rxhdr, sizeof(*rxhdr),
                                q->mmio_base + B43_PIO_RXDATA,
                                sizeof(u16));
         }
         /* Sanity checks. */
-        len = le16_to_cpu(wl->rxhdr.frame_len);
+        len = le16_to_cpu(rxhdr->frame_len);
         if (unlikely(len > 0x700)) {
                 err_msg = "len > 0x700";
                 goto rx_error;
@@ -682,7 +691,7 @@ data_ready:
                 goto rx_error;
         }
 
-        macstat = le32_to_cpu(wl->rxhdr.mac_status);
+        macstat = le32_to_cpu(rxhdr->mac_status);
         if (macstat & B43_RX_MAC_FCSERR) {
                 if (!(q->dev->wl->filter_flags & FIF_FCSFAIL)) {
                         /* Drop frames with failed FCS. */
@@ -707,22 +716,25 @@ data_ready:
                                q->mmio_base + B43_PIO8_RXDATA,
                                sizeof(u32));
                 if (len & 3) {
+                        u8 *tail = wl->pio_tailspace;
+                        BUILD_BUG_ON(sizeof(wl->pio_tailspace) < 4);
+
                         /* Read the last few bytes. */
-                        ssb_block_read(dev->dev, wl->rx_tail, 4,
+                        ssb_block_read(dev->dev, tail, 4,
                                        q->mmio_base + B43_PIO8_RXDATA,
                                        sizeof(u32));
                         switch (len & 3) {
                         case 3:
-                                skb->data[len + padding - 3] = wl->rx_tail[0];
-                                skb->data[len + padding - 2] = wl->rx_tail[1];
-                                skb->data[len + padding - 1] = wl->rx_tail[2];
+                                skb->data[len + padding - 3] = tail[0];
+                                skb->data[len + padding - 2] = tail[1];
+                                skb->data[len + padding - 1] = tail[2];
                                 break;
                         case 2:
-                                skb->data[len + padding - 2] = wl->rx_tail[0];
-                                skb->data[len + padding - 1] = wl->rx_tail[1];
+                                skb->data[len + padding - 2] = tail[0];
+                                skb->data[len + padding - 1] = tail[1];
                                 break;
                         case 1:
-                                skb->data[len + padding - 1] = wl->rx_tail[0];
+                                skb->data[len + padding - 1] = tail[0];
                                 break;
                         }
                 }
@@ -731,15 +743,18 @@ data_ready:
                                q->mmio_base + B43_PIO_RXDATA,
                                sizeof(u16));
                 if (len & 1) {
+                        u8 *tail = wl->pio_tailspace;
+                        BUILD_BUG_ON(sizeof(wl->pio_tailspace) < 2);
+
                         /* Read the last byte. */
-                        ssb_block_read(dev->dev, wl->rx_tail, 2,
+                        ssb_block_read(dev->dev, tail, 2,
                                        q->mmio_base + B43_PIO_RXDATA,
                                        sizeof(u16));
-                        skb->data[len + padding - 1] = wl->rx_tail[0];
+                        skb->data[len + padding - 1] = tail[0];
                 }
         }
 
-        b43_rx(q->dev, skb, &wl->rxhdr);
+        b43_rx(q->dev, skb, rxhdr);
 
         return 1;
 
diff --git a/drivers/net/wireless/b43/xmit.c b/drivers/net/wireless/b43/xmit.c
index f4e9695ec186..51d68971f6fa 100644
--- a/drivers/net/wireless/b43/xmit.c
+++ b/drivers/net/wireless/b43/xmit.c
@@ -27,7 +27,7 @@
 
 */
 
-#include "b43.h"
+#include "xmit.h"
 #include "phy_common.h"
 #include "dma.h"
 #include "pio.h"