bcma: don't map/unmap a subset of the PCI config space

For PCI config space access offsets < 256 for device '0',
bcma_extpci_write_config performs an 'ioremap_nocache' on a 4 byte
section of the PCI config space (an area that has already
previously been mapped), and then subsequently unmaps that 4 byte
section.  This can't be a good thing for future read access from
that now unmapped location.  Modify the config space writes to use
the existing access functions (similar to how it is done for the reads).
Signed-off-by: Nathan Hintz <nlhintz@hotmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/bcma/driver_pci_host.c

@@ -149,7 +149,7 @@ static int bcma_extpci_write_config(struct bcma_drv_pci *pc, unsigned int dev,
 				   const void *buf, int len)
 {
 	int err = -EINVAL;
-	u32 addr = 0, val = 0;
+	u32 addr, val;
 	void __iomem *mmio = 0;
 	u16 chipid = pc->core->bus->chipinfo.id;
 
@@ -165,12 +165,10 @@ static int bcma_extpci_write_config(struct bcma_drv_pci *pc, unsigned int dev,
 		 * requires indirect access.
 		 */
 		if (off < PCI_CONFIG_SPACE_SIZE) {
-			addr = pc->core->addr + BCMA_CORE_PCI_PCICFG0;
+			addr = BCMA_CORE_PCI_PCICFG0;
 			addr |= (func << 8);
 			addr |= (off & 0xfc);
-			mmio = ioremap_nocache(addr, sizeof(val));
-			if (!mmio)
-				goto out;
+			val = pcicore_read32(pc, addr);
 		}
 	} else {
 		addr = bcma_get_cfgspace_addr(pc, dev, func, off);
@@ -189,12 +187,10 @@ static int bcma_extpci_write_config(struct bcma_drv_pci *pc, unsigned int dev,
 
 	switch (len) {
 	case 1:
-		val = readl(mmio);
 		val &= ~(0xFF << (8 * (off & 3)));
 		val |= *((const u8 *)buf) << (8 * (off & 3));
 		break;
 	case 2:
-		val = readl(mmio);
 		val &= ~(0xFFFF << (8 * (off & 3)));
 		val |= *((const u16 *)buf) << (8 * (off & 3));
 		break;
@@ -202,13 +198,17 @@ static int bcma_extpci_write_config(struct bcma_drv_pci *pc, unsigned int dev,
 		val = *((const u32 *)buf);
 		break;
 	}
-	if (dev == 0 && !addr) {
+	if (dev == 0) {
 		/* accesses to config registers with offsets >= 256
 		 * requires indirect access.
 		 */
-		addr = (func << 12);
-		addr |= (off & 0x0FFF);
-		bcma_pcie_write_config(pc, addr, val);
+		if (off >= PCI_CONFIG_SPACE_SIZE) {
+			addr = (func << 12);
+			addr |= (off & 0x0FFF);
+			bcma_pcie_write_config(pc, addr, val);
+		} else {
+			pcicore_write32(pc, addr, val);
+		}
 	} else {
 		writel(val, mmio);