b43: Use SSB block-I/O to do PIO

This changes the b43-PIO code to use the new SSB block-I/O.
This reduces the overhead by removing lots of function calls, pointer
dereferencing, if-conditionals any byteswapping for each packet data word.

This also fixes a harmless sparse endianness warning.

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

1 files changed, 90 insertions, 83 deletions

diff --git a/drivers/net/wireless/b43/pio.c b/drivers/net/wireless/b43/pio.c
index e73769ac027..fcacafb0434 100644
--- a/drivers/net/wireless/b43/pio.c
+++ b/drivers/net/wireless/b43/pio.c
@@ -338,27 +338,28 @@ static struct b43_pio_txqueue * select_queue_by_priority(struct b43_wldev *dev,
         return q;
 }
 
-static inline void tx_write_2byte_queue(struct b43_pio_txqueue *q,
-                                        u16 *ctl,
-                                        const void *_data,
-                                        unsigned int data_len)
+static u16 tx_write_2byte_queue(struct b43_pio_txqueue *q,
+                                u16 ctl,
+                                const void *_data,
+                                unsigned int data_len)
 {
+        struct b43_wldev *dev = q->dev;
         const u8 *data = _data;
-        unsigned int i;
-        u16 value;
-
-        *ctl |= B43_PIO_TXCTL_WRITELO | B43_PIO_TXCTL_WRITEHI;
-        b43_piotx_write16(q, B43_PIO_TXCTL, *ctl);
-        for (i = 0; i < data_len; i += 2) {
-                value = data[i];
-                if (i + 1 < data_len) {
-                        value |= (u16)(data[i + 1]) << 8;
-                } else {
-                        *ctl &= ~B43_PIO_TXCTL_WRITEHI;
-                        b43_piotx_write16(q, B43_PIO_TXCTL, *ctl);
-                }
-                b43_piotx_write16(q, B43_PIO_TXDATA, value);
+
+        ctl |= B43_PIO_TXCTL_WRITELO | B43_PIO_TXCTL_WRITEHI;
+        b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
+
+        ssb_block_write(dev->dev, data, (data_len & ~1),
+                        q->mmio_base + B43_PIO_TXDATA,
+                        sizeof(u16));
+        if (data_len & 1) {
+                /* Write the last byte. */
+                ctl &= ~B43_PIO_TXCTL_WRITEHI;
+                b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
+                b43_piotx_write16(q, B43_PIO_TXDATA, data[data_len - 1]);
         }
+
+        return ctl;
 }
 
 static void pio_tx_frame_2byte_queue(struct b43_pio_txpacket *pack,
@@ -374,51 +375,53 @@ static void pio_tx_frame_2byte_queue(struct b43_pio_txpacket *pack,
         ctl &= ~B43_PIO_TXCTL_EOF;
 
         /* Transfer the header data. */
-        tx_write_2byte_queue(q, &ctl, hdr, hdrlen);
+        ctl = tx_write_2byte_queue(q, ctl, hdr, hdrlen);
         /* Transfer the frame data. */
-        tx_write_2byte_queue(q, &ctl, frame, frame_len);
+        ctl = tx_write_2byte_queue(q, ctl, frame, frame_len);
 
         ctl |= B43_PIO_TXCTL_EOF;
         b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
 }
 
-static inline void tx_write_4byte_queue(struct b43_pio_txqueue *q,
-                                        u32 *ctl,
-                                        const void *_data,
-                                        unsigned int data_len)
+static u32 tx_write_4byte_queue(struct b43_pio_txqueue *q,
+                                u32 ctl,
+                                const void *_data,
+                                unsigned int data_len)
 {
+        struct b43_wldev *dev = q->dev;
         const u8 *data = _data;
-        unsigned int i;
-        u32 value;
-        bool ctl_changed = 0;
-
-        *ctl |= B43_PIO8_TXCTL_0_7 | B43_PIO8_TXCTL_8_15 |
-                B43_PIO8_TXCTL_16_23 | B43_PIO8_TXCTL_24_31;
-        b43_piotx_write32(q, B43_PIO8_TXCTL, *ctl);
-        for (i = 0; i < data_len; i += 4) {
-                value = data[i];
-                if (i + 1 < data_len) {
-                        value |= (u32)(data[i + 1]) << 8;
-                } else {
-                        *ctl &= ~B43_PIO8_TXCTL_8_15;
-                        ctl_changed = 1;
-                }
-                if (i + 2 < data_len) {
-                        value |= (u32)(data[i + 2]) << 16;
-                } else {
-                        *ctl &= ~B43_PIO8_TXCTL_16_23;
-                        ctl_changed = 1;
-                }
-                if (i + 3 < data_len) {
-                        value |= (u32)(data[i + 3]) << 24;
-                } else {
-                        *ctl &= ~B43_PIO8_TXCTL_24_31;
-                        ctl_changed = 1;
+
+        ctl |= B43_PIO8_TXCTL_0_7 | B43_PIO8_TXCTL_8_15 |
+               B43_PIO8_TXCTL_16_23 | B43_PIO8_TXCTL_24_31;
+        b43_piotx_write32(q, B43_PIO8_TXCTL, ctl);
+
+        ssb_block_write(dev->dev, data, (data_len & ~3),
+                        q->mmio_base + B43_PIO8_TXDATA,
+                        sizeof(u32));
+        if (data_len & 3) {
+                u32 value = 0;
+
+                /* Write the last few bytes. */
+                ctl &= ~(B43_PIO8_TXCTL_8_15 | B43_PIO8_TXCTL_16_23 |
+                         B43_PIO8_TXCTL_24_31);
+                data = &(data[data_len - 1]);
+                switch (data_len & 3) {
+                case 3:
+                        ctl |= B43_PIO8_TXCTL_16_23;
+                        value |= (u32)(*data) << 16;
+                        data--;
+                case 2:
+                        ctl |= B43_PIO8_TXCTL_8_15;
+                        value |= (u32)(*data) << 8;
+                        data--;
+                case 1:
+                        value |= (u32)(*data);
                 }
-                if (ctl_changed)
-                        b43_piotx_write32(q, B43_PIO8_TXCTL, *ctl);
+                b43_piotx_write32(q, B43_PIO8_TXCTL, ctl);
                 b43_piotx_write32(q, B43_PIO8_TXDATA, value);
         }
+
+        return ctl;
 }
 
 static void pio_tx_frame_4byte_queue(struct b43_pio_txpacket *pack,
@@ -434,9 +437,9 @@ static void pio_tx_frame_4byte_queue(struct b43_pio_txpacket *pack,
         ctl &= ~B43_PIO8_TXCTL_EOF;
 
         /* Transfer the header data. */
-        tx_write_4byte_queue(q, &ctl, hdr, hdrlen);
+        ctl = tx_write_4byte_queue(q, ctl, hdr, hdrlen);
         /* Transfer the frame data. */
-        tx_write_4byte_queue(q, &ctl, frame, frame_len);
+        ctl = tx_write_4byte_queue(q, ctl, frame, frame_len);
 
         ctl |= B43_PIO8_TXCTL_EOF;
         b43_piotx_write32(q, B43_PIO_TXCTL, ctl);
@@ -627,6 +630,7 @@ void b43_pio_get_tx_stats(struct b43_wldev *dev,
 /* Returns whether we should fetch another frame. */
 static bool pio_rx_frame(struct b43_pio_rxqueue *q)
 {
+        struct b43_wldev *dev = q->dev;
         struct b43_rxhdr_fw4 rxhdr;
         u16 len;
         u32 macstat;
@@ -672,21 +676,13 @@ data_ready:
 
         /* Get the preamble (RX header) */
         if (q->rev >= 8) {
-                u32 *preamble = (u32 *)&rxhdr;
-                u32 value;
-
-                for (i = 0; i < sizeof(rxhdr); i += 4) {
-                        value = b43_piorx_read32(q, B43_PIO8_RXDATA);
-                        preamble[i / 4] = cpu_to_le32(value);
-                }
+                ssb_block_read(dev->dev, &rxhdr, sizeof(rxhdr),
+                               q->mmio_base + B43_PIO8_RXDATA,
+                               sizeof(u32));
         } else {
-                u16 *preamble = (u16 *)&rxhdr;
-                u16 value;
-
-                for (i = 0; i < sizeof(rxhdr); i += 2) {
-                        value = b43_piorx_read16(q, B43_PIO_RXDATA);
-                        preamble[i / 2] = cpu_to_le16(value);
-                }
+                ssb_block_read(dev->dev, &rxhdr, sizeof(rxhdr),
+                               q->mmio_base + B43_PIO_RXDATA,
+                               sizeof(u16));
         }
         /* Sanity checks. */
         len = le16_to_cpu(rxhdr.frame_len);
@@ -720,26 +716,37 @@ data_ready:
         skb_reserve(skb, 2);
         skb_put(skb, len + padding);
         if (q->rev >= 8) {
-                u32 value;
-
-                for (i = padding; i < len + padding; i += 4) {
+                ssb_block_read(dev->dev, skb->data + padding, (len & ~3),
+                               q->mmio_base + B43_PIO8_RXDATA,
+                               sizeof(u32));
+                if (len & 3) {
+                        u32 value;
+                        char *data;
+
+                        /* Read the last few bytes. */
                         value = b43_piorx_read32(q, B43_PIO8_RXDATA);
-                        skb->data[i] = value;
-                        if ((i + 1) < (len + padding))
-                                skb->data[i + 1] = value >> 8;
-                        if ((i + 2) < (len + padding))
-                                skb->data[i + 2] = value >> 16;
-                        if ((i + 3) < (len + padding))
-                                skb->data[i + 3] = value >> 24;
+                        data = &(skb->data[len + padding - 1]);
+                        switch (len & 3) {
+                        case 3:
+                                *data = (value >> 16);
+                                data--;
+                        case 2:
+                                *data = (value >> 8);
+                                data--;
+                        case 1:
+                                *data = value;
+                        }
                 }
         } else {
-                u16 value;
+                ssb_block_read(dev->dev, skb->data + padding, (len & ~1),
+                               q->mmio_base + B43_PIO_RXDATA,
+                               sizeof(u16));
+                if (len & 1) {
+                        u16 value;
 
-                for (i = padding; i < len + padding; i += 2) {
+                        /* Read the last byte. */
                         value = b43_piorx_read16(q, B43_PIO_RXDATA);
-                        skb->data[i] = value;
-                        if ((i + 1) < (len + padding))
-                                skb->data[i + 1] = value >> 8;
+                        skb->data[len + padding - 1] = value;
                 }
         }