3c59x: Specify window explicitly for access to windowed registers

Currently much of the code assumes that a specific window has been
selected, while a few functions save and restore the window.  This
makes it impossible to introduce fine-grained locking.

Make those assumptions explicit by introducing wrapper functions
to set the window and read/write a register.  Use these everywhere
except vortex_interrupt(), vortex_start_xmit() and vortex_rx().
These set the window just once, or not at all in the case of
vortex_rx() as it should always be called from vortex_interrupt().

Cache the current window in struct vortex_private to avoid
unnecessary hardware writes.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Arne Nordmark <nordmark@mech.kth.se> [against 2.6.32]
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 140 insertions, 148 deletions

diff --git a/drivers/net/3c59x.c b/drivers/net/3c59x.c
index d75803e6e527..beddef98ad92 100644
--- a/drivers/net/3c59x.c
+++ b/drivers/net/3c59x.c
@@ -435,7 +435,6 @@ MODULE_DEVICE_TABLE(pci, vortex_pci_tbl);
    First the windows.  There are eight register windows, with the command
    and status registers available in each.
    */
-#define EL3WINDOW(win_num) iowrite16(SelectWindow + (win_num), ioaddr + EL3_CMD)
 #define EL3_CMD 0x0e
 #define EL3_STATUS 0x0e
 
@@ -647,8 +646,35 @@ struct vortex_private {
         u16 io_size;                                            /* Size of PCI region (for release_region) */
         spinlock_t lock;                                        /* Serialise access to device & its vortex_private */
         struct mii_if_info mii;                         /* MII lib hooks/info */
+        int window;                                     /* Register window */
 };
 
+static void window_set(struct vortex_private *vp, int window)
+{
+        if (window != vp->window) {
+                iowrite16(SelectWindow + window, vp->ioaddr + EL3_CMD);
+                vp->window = window;
+        }
+}
+
+#define DEFINE_WINDOW_IO(size)                                          \
+static u ## size                                                        \
+window_read ## size(struct vortex_private *vp, int window, int addr)    \
+{                                                                       \
+        window_set(vp, window);                                         \
+        return ioread ## size(vp->ioaddr + addr);                       \
+}                                                                       \
+static void                                                             \
+window_write ## size(struct vortex_private *vp, u ## size value,        \
+                     int window, int addr)                              \
+{                                                                       \
+        window_set(vp, window);                                         \
+        iowrite ## size(value, vp->ioaddr + addr);                      \
+}
+DEFINE_WINDOW_IO(8)
+DEFINE_WINDOW_IO(16)
+DEFINE_WINDOW_IO(32)
+
 #ifdef CONFIG_PCI
 #define DEVICE_PCI(dev) (((dev)->bus == &pci_bus_type) ? to_pci_dev((dev)) : NULL)
 #else
@@ -711,7 +737,7 @@ static int vortex_probe1(struct device *gendev, void __iomem *ioaddr, int irq,
 static int vortex_up(struct net_device *dev);
 static void vortex_down(struct net_device *dev, int final);
 static int vortex_open(struct net_device *dev);
-static void mdio_sync(void __iomem *ioaddr, int bits);
+static void mdio_sync(struct vortex_private *vp, int bits);
 static int mdio_read(struct net_device *dev, int phy_id, int location);
 static void mdio_write(struct net_device *vp, int phy_id, int location, int value);
 static void vortex_timer(unsigned long arg);
@@ -1119,6 +1145,7 @@ static int __devinit vortex_probe1(struct device *gendev,
         vp->has_nway = (vci->drv_flags & HAS_NWAY) ? 1 : 0;
         vp->io_size = vci->io_size;
         vp->card_idx = card_idx;
+        vp->window = -1;
 
         /* module list only for Compaq device */
         if (gendev == NULL) {
@@ -1205,7 +1232,6 @@ static int __devinit vortex_probe1(struct device *gendev,
         vp->mii.force_media = vp->full_duplex;
         vp->options = option;
         /* Read the station address from the EEPROM. */
-        EL3WINDOW(0);
         {
                 int base;
 
@@ -1218,14 +1244,15 @@ static int __devinit vortex_probe1(struct device *gendev,
 
                 for (i = 0; i < 0x40; i++) {
                         int timer;
-                        iowrite16(base + i, ioaddr + Wn0EepromCmd);
+                        window_write16(vp, base + i, 0, Wn0EepromCmd);
                         /* Pause for at least 162 us. for the read to take place. */
                         for (timer = 10; timer >= 0; timer--) {
                                 udelay(162);
-                                if ((ioread16(ioaddr + Wn0EepromCmd) & 0x8000) == 0)
+                                if ((window_read16(vp, 0, Wn0EepromCmd) &
+                                     0x8000) == 0)
                                         break;
                         }
-                        eeprom[i] = ioread16(ioaddr + Wn0EepromData);
+                        eeprom[i] = window_read16(vp, 0, Wn0EepromData);
                 }
         }
         for (i = 0; i < 0x18; i++)
@@ -1250,9 +1277,8 @@ static int __devinit vortex_probe1(struct device *gendev,
                 pr_err("*** EEPROM MAC address is invalid.\n");
                 goto free_ring; /* With every pack */
         }
-        EL3WINDOW(2);
         for (i = 0; i < 6; i++)
-                iowrite8(dev->dev_addr[i], ioaddr + i);
+                window_write8(vp, dev->dev_addr[i], 2, i);
 
         if (print_info)
                 pr_cont(", IRQ %d\n", dev->irq);
@@ -1261,8 +1287,7 @@ static int __devinit vortex_probe1(struct device *gendev,
                 pr_warning(" *** Warning: IRQ %d is unlikely to work! ***\n",
                            dev->irq);
 
-        EL3WINDOW(4);
-        step = (ioread8(ioaddr + Wn4_NetDiag) & 0x1e) >> 1;
+        step = (window_read8(vp, 4, Wn4_NetDiag) & 0x1e) >> 1;
         if (print_info) {
                 pr_info("  product code %02x%02x rev %02x.%d date %02d-%02d-%02d\n",
                         eeprom[6]&0xff, eeprom[6]>>8, eeprom[0x14],
@@ -1285,17 +1310,15 @@ static int __devinit vortex_probe1(struct device *gendev,
                                 (unsigned long long)pci_resource_start(pdev, 2),
                                 vp->cb_fn_base);
                 }
-                EL3WINDOW(2);
 
-                n = ioread16(ioaddr + Wn2_ResetOptions) & ~0x4010;
+                n = window_read16(vp, 2, Wn2_ResetOptions) & ~0x4010;
                 if (vp->drv_flags & INVERT_LED_PWR)
                         n |= 0x10;
                 if (vp->drv_flags & INVERT_MII_PWR)
                         n |= 0x4000;
-                iowrite16(n, ioaddr + Wn2_ResetOptions);
+                window_write16(vp, n, 2, Wn2_ResetOptions);
                 if (vp->drv_flags & WNO_XCVR_PWR) {
-                        EL3WINDOW(0);
-                        iowrite16(0x0800, ioaddr);
+                        window_write16(vp, 0x0800, 0, 0);
                 }
         }
 
@@ -1313,14 +1336,13 @@ static int __devinit vortex_probe1(struct device *gendev,
         {
                 static const char * const ram_split[] = {"5:3", "3:1", "1:1", "3:5"};
                 unsigned int config;
-                EL3WINDOW(3);
-                vp->available_media = ioread16(ioaddr + Wn3_Options);
+                vp->available_media = window_read16(vp, 3, Wn3_Options);
                 if ((vp->available_media & 0xff) == 0)          /* Broken 3c916 */
                         vp->available_media = 0x40;
-                config = ioread32(ioaddr + Wn3_Config);
+                config = window_read32(vp, 3, Wn3_Config);
                 if (print_info) {
                         pr_debug("  Internal config register is %4.4x, transceivers %#x.\n",
-                                config, ioread16(ioaddr + Wn3_Options));
+                                config, window_read16(vp, 3, Wn3_Options));
                         pr_info("  %dK %s-wide RAM %s Rx:Tx split, %s%s interface.\n",
                                    8 << RAM_SIZE(config),
                                    RAM_WIDTH(config) ? "word" : "byte",
@@ -1346,7 +1368,6 @@ static int __devinit vortex_probe1(struct device *gendev,