P54: use temporary variables to reduce size of generated code

When there are 2 linked structures, using a temporary variable to hold a pointer
to the often used structure usually produces better code (smaller and faster)
since compiler does not have to constantly re-fetch data from the first structure.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/p54pci.c b/drivers/net/wireless/p54pci.c
index 410b543..b7a3bde 100644 (file)
--- a/drivers/net/wireless/p54pci.c
+++ b/drivers/net/wireless/p54pci.c
@@ -141,6 +141,7 @@ static irqreturn_t p54p_simple_interrupt(int irq, void *dev_id)
 static int p54p_read_eeprom(struct ieee80211_hw *dev)
 {
        struct p54p_priv *priv = dev->priv;
+       struct p54p_ring_control *ring_control = priv->ring_control;
        int err;
        struct p54_control_hdr *hdr;
        void *eeprom;
@@ -164,7 +165,7 @@ static int p54p_read_eeprom(struct ieee80211_hw *dev)
                goto out;
        }
 
-       memset(priv->ring_control, 0, sizeof(*priv->ring_control));
+       memset(ring_control, 0, sizeof(*ring_control));
        P54P_WRITE(ring_control_base, priv->ring_control_dma);
        P54P_READ(ring_control_base);
        udelay(10);
@@ -194,14 +195,14 @@ static int p54p_read_eeprom(struct ieee80211_hw *dev)
        tx_mapping = pci_map_single(priv->pdev, (void *)hdr,
                                    EEPROM_READBACK_LEN, PCI_DMA_TODEVICE);
 
-       priv->ring_control->rx_mgmt[0].host_addr = cpu_to_le32(rx_mapping);
-       priv->ring_control->rx_mgmt[0].len = cpu_to_le16(0x2010);
-       priv->ring_control->tx_data[0].host_addr = cpu_to_le32(tx_mapping);
-       priv->ring_control->tx_data[0].device_addr = hdr->req_id;
-       priv->ring_control->tx_data[0].len = cpu_to_le16(EEPROM_READBACK_LEN);
+       ring_control->rx_mgmt[0].host_addr = cpu_to_le32(rx_mapping);
+       ring_control->rx_mgmt[0].len = cpu_to_le16(0x2010);
+       ring_control->tx_data[0].host_addr = cpu_to_le32(tx_mapping);
+       ring_control->tx_data[0].device_addr = hdr->req_id;
+       ring_control->tx_data[0].len = cpu_to_le16(EEPROM_READBACK_LEN);
 
-       priv->ring_control->host_idx[2] = cpu_to_le32(1);
-       priv->ring_control->host_idx[1] = cpu_to_le32(1);
+       ring_control->host_idx[2] = cpu_to_le32(1);
+       ring_control->host_idx[1] = cpu_to_le32(1);
 
        wmb();
        mdelay(100);
@@ -215,8 +216,8 @@ static int p54p_read_eeprom(struct ieee80211_hw *dev)
        pci_unmap_single(priv->pdev, rx_mapping,
                         0x2010, PCI_DMA_FROMDEVICE);
 
-       alen = le16_to_cpu(priv->ring_control->rx_mgmt[0].len);
-       if (le32_to_cpu(priv->ring_control->device_idx[2]) != 1 ||
+       alen = le16_to_cpu(ring_control->rx_mgmt[0].len);
+       if (le32_to_cpu(ring_control->device_idx[2]) != 1 ||
            alen < 0x10) {
                printk(KERN_ERR "%s (prism54pci): Cannot read eeprom!\n",
                       pci_name(priv->pdev));
@@ -239,16 +240,17 @@ static int p54p_read_eeprom(struct ieee80211_hw *dev)
 static void p54p_refill_rx_ring(struct ieee80211_hw *dev)
 {
        struct p54p_priv *priv = dev->priv;
+       struct p54p_ring_control *ring_control = priv->ring_control;
        u32 limit, host_idx, idx;
 
-       host_idx = le32_to_cpu(priv->ring_control->host_idx[0]);
+       host_idx = le32_to_cpu(ring_control->host_idx[0]);
        limit = host_idx;
-       limit -= le32_to_cpu(priv->ring_control->device_idx[0]);
-       limit = ARRAY_SIZE(priv->ring_control->rx_data) - limit;
+       limit -= le32_to_cpu(ring_control->device_idx[0]);
+       limit = ARRAY_SIZE(ring_control->rx_data) - limit;
 
-       idx = host_idx % ARRAY_SIZE(priv->ring_control->rx_data);
+       idx = host_idx % ARRAY_SIZE(ring_control->rx_data);
        while (limit-- > 1) {
-               struct p54p_desc *desc = &priv->ring_control->rx_data[idx];
+               struct p54p_desc *desc = &ring_control->rx_data[idx];
 
                if (!desc->host_addr) {
                        struct sk_buff *skb;
@@ -270,17 +272,18 @@ static void p54p_refill_rx_ring(struct ieee80211_hw *dev)
 
                idx++;
                host_idx++;
-               idx %= ARRAY_SIZE(priv->ring_control->rx_data);
+               idx %= ARRAY_SIZE(ring_control->rx_data);
        }
 
        wmb();
-       priv->ring_control->host_idx[0] = cpu_to_le32(host_idx);
+       ring_control->host_idx[0] = cpu_to_le32(host_idx);
 }
 
 static irqreturn_t p54p_interrupt(int irq, void *dev_id)
 {
        struct ieee80211_hw *dev = dev_id;
        struct p54p_priv *priv = dev->priv;
+       struct p54p_ring_control *ring_control = priv->ring_control;
        __le32 reg;
 
        spin_lock(&priv->lock);
@@ -298,12 +301,12 @@ static irqreturn_t p54p_interrupt(int irq, void *dev_id)
                struct p54p_desc *desc;
                u32 idx, i;
                i = priv->tx_idx;
-               i %= ARRAY_SIZE(priv->ring_control->tx_data);
-               priv->tx_idx = idx = le32_to_cpu(priv->ring_control->device_idx[1]);
-               idx %= ARRAY_SIZE(priv->ring_control->tx_data);
+               i %= ARRAY_SIZE(ring_control->tx_data);
+               priv->tx_idx = idx = le32_to_cpu(ring_control->device_idx[1]);
+               idx %= ARRAY_SIZE(ring_control->tx_data);
 
                while (i != idx) {
-                       desc = &priv->ring_control->tx_data[i];
+                       desc = &ring_control->tx_data[i];
                        if (priv->tx_buf[i]) {
                                kfree(priv->tx_buf[i]);
                                priv->tx_buf[i] = NULL;
@@ -318,17 +321,17 @@ static irqreturn_t p54p_interrupt(int irq, void *dev_id)
                        desc->flags = 0;
 
                        i++;
-                       i %= ARRAY_SIZE(priv->ring_control->tx_data);
+                       i %= ARRAY_SIZE(ring_control->tx_data);
                }
 
                i = priv->rx_idx;
-               i %= ARRAY_SIZE(priv->ring_control->rx_data);
-               priv->rx_idx = idx = le32_to_cpu(priv->ring_control->device_idx[0]);
-               idx %= ARRAY_SIZE(priv->ring_control->rx_data);
+               i %= ARRAY_SIZE(ring_control->rx_data);
+               priv->rx_idx = idx = le32_to_cpu(ring_control->device_idx[0]);
+               idx %= ARRAY_SIZE(ring_control->rx_data);
                while (i != idx) {
                        u16 len;
                        struct sk_buff *skb;
-                       desc = &priv->ring_control->rx_data[i];
+                       desc = &ring_control->rx_data[i];
                        len = le16_to_cpu(desc->len);
                        skb = priv->rx_buf[i];
 
@@ -347,7 +350,7 @@ static irqreturn_t p54p_interrupt(int irq, void *dev_id)
                        }
 
                        i++;
-                       i %= ARRAY_SIZE(priv->ring_control->rx_data);
+                       i %= ARRAY_SIZE(ring_control->rx_data);
                }
 
                p54p_refill_rx_ring(dev);
@@ -366,6 +369,7 @@ static void p54p_tx(struct ieee80211_hw *dev, struct p54_control_hdr *data,
                    size_t len, int free_on_tx)
 {
        struct p54p_priv *priv = dev->priv;
+       struct p54p_ring_control *ring_control = priv->ring_control;
        unsigned long flags;
        struct p54p_desc *desc;
        dma_addr_t mapping;
@@ -373,19 +377,19 @@ static void p54p_tx(struct ieee80211_hw *dev, struct p54_control_hdr *data,
 
        spin_lock_irqsave(&priv->lock, flags);
 
-       device_idx = le32_to_cpu(priv->ring_control->device_idx[1]);
-       idx = le32_to_cpu(priv->ring_control->host_idx[1]);
-       i = idx % ARRAY_SIZE(priv->ring_control->tx_data);
+       device_idx = le32_to_cpu(ring_control->device_idx[1]);
+       idx = le32_to_cpu(ring_control->host_idx[1]);
+       i = idx % ARRAY_SIZE(ring_control->tx_data);
 
        mapping = pci_map_single(priv->pdev, data, len, PCI_DMA_TODEVICE);
-       desc = &priv->ring_control->tx_data[i];
+       desc = &ring_control->tx_data[i];
        desc->host_addr = cpu_to_le32(mapping);
        desc->device_addr = data->req_id;
        desc->len = cpu_to_le16(len);
        desc->flags = 0;
 
        wmb();
-       priv->ring_control->host_idx[1] = cpu_to_le32(idx + 1);
+       ring_control->host_idx[1] = cpu_to_le32(idx + 1);
 
        if (free_on_tx)
                priv->tx_buf[i] = data;
@@ -397,7 +401,7 @@ static void p54p_tx(struct ieee80211_hw *dev, struct p54_control_hdr *data,
 
        /* FIXME: unlikely to happen because the device usually runs out of
           memory before we fill the ring up, but we can make it impossible */
-       if (idx - device_idx > ARRAY_SIZE(priv->ring_control->tx_data) - 2)
+       if (idx - device_idx > ARRAY_SIZE(ring_control->tx_data) - 2)
                printk(KERN_INFO "%s: tx overflow.\n", wiphy_name(dev->wiphy));
 }
 
@@ -457,6 +461,7 @@ static int p54p_open(struct ieee80211_hw *dev)
 static void p54p_stop(struct ieee80211_hw *dev)
 {
        struct p54p_priv *priv = dev->priv;
+       struct p54p_ring_control *ring_control = priv->ring_control;
        unsigned int i;
        struct p54p_desc *desc;
 
@@ -469,7 +474,7 @@ static void p54p_stop(struct ieee80211_hw *dev)
        P54P_WRITE(dev_int, cpu_to_le32(ISL38XX_DEV_INT_RESET));
 
        for (i = 0; i < ARRAY_SIZE(priv->rx_buf); i++) {
-               desc = &priv->ring_control->rx_data[i];
+               desc = &ring_control->rx_data[i];
                if (desc->host_addr)
                        pci_unmap_single(priv->pdev, le32_to_cpu(desc->host_addr),
                                         MAX_RX_SIZE, PCI_DMA_FROMDEVICE);
@@ -478,7 +483,7 @@ static void p54p_stop(struct ieee80211_hw *dev)
        }
 
        for (i = 0; i < ARRAY_SIZE(priv->tx_buf); i++) {
-               desc = &priv->ring_control->tx_data[i];
+               desc = &ring_control->tx_data[i];
                if (desc->host_addr)
                        pci_unmap_single(priv->pdev, le32_to_cpu(desc->host_addr),
                                         le16_to_cpu(desc->len), PCI_DMA_TODEVICE);
@@ -487,7 +492,7 @@ static void p54p_stop(struct ieee80211_hw *dev)
                priv->tx_buf[i] = NULL;
        }
 
-       memset(priv->ring_control, 0, sizeof(*priv->ring_control));
+       memset(ring_control, 0, sizeof(ring_control));
 }
 
 static int __devinit p54p_probe(struct pci_dev *pdev,