drm/nouveau: map first page of mmio early and determine chipset earlier

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_drv.h

@@ -695,14 +695,14 @@ struct nv04_mode_state {
 };
 
 enum nouveau_card_type {
-	NV_04      = 0x00,
+	NV_04      = 0x04,
 	NV_10      = 0x10,
 	NV_20      = 0x20,
 	NV_30      = 0x30,
 	NV_40      = 0x40,
 	NV_50      = 0x50,
 	NV_C0      = 0xc0,
-	NV_D0      = 0xd0
+	NV_D0      = 0xd0,
 };
 
 struct drm_nouveau_private {

drivers/gpu/drm/nouveau/nouveau_state.c

@@ -993,7 +993,7 @@ static int nouveau_remove_conflicting_drivers(struct drm_device *dev)
 int nouveau_load(struct drm_device *dev, unsigned long flags)
 {
 	struct drm_nouveau_private *dev_priv;
-	uint32_t reg0, strap;
+	uint32_t reg0 = ~0, strap;
 	resource_size_t mmio_start_offs;
 	int ret;
 
@@ -1012,49 +1012,21 @@ int nouveau_load(struct drm_device *dev, unsigned long flags)
 	NV_DEBUG(dev, "vendor: 0x%X device: 0x%X class: 0x%X\n",
 		 dev->pci_vendor, dev->pci_device, dev->pdev->class);
 
-	/* resource 0 is mmio regs */
-	/* resource 1 is linear FB */
-	/* resource 2 is RAMIN (mmio regs + 0x1000000) */
-	/* resource 6 is bios */
-
-	/* map the mmio regs */
-	mmio_start_offs = pci_resource_start(dev->pdev, 0);
-	dev_priv->mmio = ioremap(mmio_start_offs, 0x00800000);
-	if (!dev_priv->mmio) {
-		NV_ERROR(dev, "Unable to initialize the mmio mapping. "
-			 "Please report your setup to " DRIVER_EMAIL "\n");
-		ret = -EINVAL;
-		goto err_priv;
-	}
-	NV_DEBUG(dev, "regs mapped ok at 0x%llx\n",
-					(unsigned long long)mmio_start_offs);
-
+	/* first up, map the start of mmio and determine the chipset */
+	dev_priv->mmio = ioremap(pci_resource_start(dev->pdev, 0), PAGE_SIZE);
+	if (dev_priv->mmio) {
 #ifdef __BIG_ENDIAN
-	/* Put the card in BE mode if it's not */
+		/* put the card into big-endian mode if it's not */
 		if (nv_rd32(dev, NV03_PMC_BOOT_1) != 0x01000001)
 			nv_wr32(dev, NV03_PMC_BOOT_1, 0x01000001);
-
 		DRM_MEMORYBARRIER();
 #endif
 
-	/* Time to determine the card architecture */
+		/* determine chipset and derive architecture from it */
 		reg0 = nv_rd32(dev, NV03_PMC_BOOT_0);
-
-	/* We're dealing with >=NV10 */
 		if ((reg0 & 0x0f000000) > 0) {
-		/* Bit 27-20 contain the architecture in hex */
 			dev_priv->chipset = (reg0 & 0xff00000) >> 20;
-	/* NV04 or NV05 */
-	} else if ((reg0 & 0xff00fff0) == 0x20004000) {
-		if (reg0 & 0x00f00000)
-			dev_priv->chipset = 0x05;
-		else
-			dev_priv->chipset = 0x04;
-	} else
-		dev_priv->chipset = 0xff;
-
 			switch (dev_priv->chipset & 0xf0) {
-	case 0x00:
 			case 0x10:
 			case 0x20:
 			case 0x30:
@@ -1077,14 +1049,41 @@ int nouveau_load(struct drm_device *dev, unsigned long flags)
 				dev_priv->card_type = NV_D0;
 				break;
 			default:
-		NV_INFO(dev, "Unsupported chipset 0x%08x\n", reg0);
+				break;
+			}
+		} else
+		if ((reg0 & 0xff00fff0) == 0x20004000) {
+			if (reg0 & 0x00f00000)
+				dev_priv->chipset = 0x05;
+			else
+				dev_priv->chipset = 0x04;
+			dev_priv->card_type = NV_04;
+		}
+
+		iounmap(dev_priv->mmio);
+	}
+
+	if (!dev_priv->card_type) {
+		NV_ERROR(dev, "unsupported chipset 0x%08x\n", reg0);
 		ret = -EINVAL;
-		goto err_mmio;
+		goto err_priv;
 	}
 
 	NV_INFO(dev, "Detected an NV%2x generation card (0x%08x)\n",
 		     dev_priv->card_type, reg0);
 
+	/* map the mmio regs */
+	mmio_start_offs = pci_resource_start(dev->pdev, 0);
+	dev_priv->mmio = ioremap(mmio_start_offs, 0x00800000);
+	if (!dev_priv->mmio) {
+		NV_ERROR(dev, "Unable to initialize the mmio mapping. "
+			 "Please report your setup to " DRIVER_EMAIL "\n");
+		ret = -EINVAL;
+		goto err_priv;
+	}
+	NV_DEBUG(dev, "regs mapped ok at 0x%llx\n",
+					(unsigned long long)mmio_start_offs);
+
 	/* determine frequency of timing crystal */
 	strap = nv_rd32(dev, 0x101000);
 	if ( dev_priv->chipset < 0x17 ||