drm/nouveau: introduce new gart type, and name _SGDMA more appropriately

In preparation for the addition of a new nv40 backend, we'll need to be
able to distinguish between a paged dma object and the on-chip GART.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -382,7 +382,8 @@ nouveau_bo_create_ttm_backend_entry(struct ttm_bo_device *bdev)
 	case NOUVEAU_GART_AGP:
 		return ttm_agp_backend_init(bdev, dev->agp->bridge);
 #endif
-	case NOUVEAU_GART_SGDMA:
+	case NOUVEAU_GART_PDMA:
+	case NOUVEAU_GART_HW:
 		return nouveau_sgdma_init_ttm(dev);
 	default:
 		NV_ERROR(dev, "Unknown GART type %d\n",
@@ -436,7 +437,8 @@ nouveau_bo_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
 				TTM_PL_FLAG_WC;
 			man->default_caching = TTM_PL_FLAG_WC;
 			break;
-		case NOUVEAU_GART_SGDMA:
+		case NOUVEAU_GART_PDMA:
+		case NOUVEAU_GART_HW:
 			man->flags = TTM_MEMTYPE_FLAG_MAPPABLE |
 				     TTM_MEMTYPE_FLAG_CMA;
 			man->available_caching = TTM_PL_MASK_CACHING;

drivers/gpu/drm/nouveau/nouveau_drv.h

@@ -691,8 +691,9 @@ struct drm_nouveau_private {
 	struct {
 		enum {
 			NOUVEAU_GART_NONE = 0,
-			NOUVEAU_GART_AGP,
-			NOUVEAU_GART_SGDMA
+			NOUVEAU_GART_AGP,	/* AGP */
+			NOUVEAU_GART_PDMA,	/* paged dma object */
+			NOUVEAU_GART_HW		/* on-chip gart/vm */
 		} type;
 		uint64_t aper_base;
 		uint64_t aper_size;

drivers/gpu/drm/nouveau/nouveau_object.c

@@ -490,16 +490,22 @@ nouveau_gpuobj_dma_new(struct nouveau_channel *chan, int class, u64 base,
 	}
 
 	if (target == NV_MEM_TARGET_GART) {
-		if (dev_priv->gart_info.type == NOUVEAU_GART_AGP) {
-			target = NV_MEM_TARGET_PCI_NOSNOOP;
-			base  += dev_priv->gart_info.aper_base;
-		} else
-		if (base != 0) {
-			base = nouveau_sgdma_get_physical(dev, base);
+		struct nouveau_gpuobj *gart = dev_priv->gart_info.sg_ctxdma;
+
+		if (dev_priv->gart_info.type == NOUVEAU_GART_PDMA) {
+			if (base == 0) {
+				nouveau_gpuobj_ref(gart, pobj);
+				return 0;
+			}
+
+			base   = nouveau_sgdma_get_physical(dev, base);
 			target = NV_MEM_TARGET_PCI;
 		} else {
-			nouveau_gpuobj_ref(dev_priv->gart_info.sg_ctxdma, pobj);
-			return 0;
+			base += dev_priv->gart_info.aper_base;
+			if (dev_priv->gart_info.type == NOUVEAU_GART_AGP)
+				target = NV_MEM_TARGET_PCI_NOSNOOP;
+			else
+				target = NV_MEM_TARGET_PCI;
 		}
 	}
 

drivers/gpu/drm/nouveau/nouveau_sgdma.c

@@ -237,6 +237,7 @@ nouveau_sgdma_init(struct drm_device *dev)
 
 		dev_priv->gart_info.aper_base = dev_priv->gart_info.vma.offset;
 		dev_priv->gart_info.aper_size = 512 * 1024 * 1024;
+		dev_priv->gart_info.type = NOUVEAU_GART_HW;
 	} else {
 		if(dev_priv->ramin_rsvd_vram < 2 * 1024 * 1024)
 			aper_size = 64 * 1024 * 1024;
@@ -266,9 +267,9 @@ nouveau_sgdma_init(struct drm_device *dev)
 		dev_priv->gart_info.sg_ctxdma = gpuobj;
 		dev_priv->gart_info.aper_base = 0;
 		dev_priv->gart_info.aper_size = aper_size;
+		dev_priv->gart_info.type = NOUVEAU_GART_PDMA;
 	}
 
-	dev_priv->gart_info.type      = NOUVEAU_GART_SGDMA;
 	return 0;
 }