drm/nouveau/kms: add support for new TTM fault callback V5

This add the support for the new fault callback, does change anything
from driver point of view, thought it should allow nouveau to add
support for unmappable VRAM.

Improvement: store the aperture base in a variable so that we don't
call a function to get it on each fault.

Patch hasn't been tested on any hw.

V2 don't derefence bo->mem.mm_node as it's not NULL only for
   VRAM or GTT
V3 update after io_mem_reserve/io_mem_free callback balancing
V4 callback has to ioremap
V5 ioremap is done by ttm
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -386,8 +386,7 @@ nouveau_bo_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
 		break;
 	case TTM_PL_VRAM:
 		man->flags = TTM_MEMTYPE_FLAG_FIXED |
-			     TTM_MEMTYPE_FLAG_MAPPABLE |
-			     TTM_MEMTYPE_FLAG_NEEDS_IOREMAP;
+			     TTM_MEMTYPE_FLAG_MAPPABLE;
 		man->available_caching = TTM_PL_FLAG_UNCACHED |
 					 TTM_PL_FLAG_WC;
 		man->default_caching = TTM_PL_FLAG_WC;
@@ -403,8 +402,7 @@ nouveau_bo_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
 	case TTM_PL_TT:
 		switch (dev_priv->gart_info.type) {
 		case NOUVEAU_GART_AGP:
-			man->flags = TTM_MEMTYPE_FLAG_MAPPABLE |
-				     TTM_MEMTYPE_FLAG_NEEDS_IOREMAP;
+			man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
 			man->available_caching = TTM_PL_FLAG_UNCACHED;
 			man->default_caching = TTM_PL_FLAG_UNCACHED;
 			break;
@@ -761,6 +759,55 @@ nouveau_bo_verify_access(struct ttm_buffer_object *bo, struct file *filp)
 	return 0;
 }
 
+static int
+nouveau_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
+{
+	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
+	struct drm_nouveau_private *dev_priv = nouveau_bdev(bdev);
+	struct drm_device *dev = dev_priv->dev;
+
+	mem->bus.addr = NULL;
+	mem->bus.offset = 0;
+	mem->bus.size = mem->num_pages << PAGE_SHIFT;
+	mem->bus.base = 0;
+	mem->bus.is_iomem = false;
+	if (!(man->flags & TTM_MEMTYPE_FLAG_MAPPABLE))
+		return -EINVAL;
+	switch (mem->mem_type) {
+	case TTM_PL_SYSTEM:
+		/* System memory */
+		return 0;
+	case TTM_PL_TT:
+#if __OS_HAS_AGP
+		if (dev_priv->gart_info.type == NOUVEAU_GART_AGP) {
+			mem->bus.offset = mem->mm_node->start << PAGE_SHIFT;
+			mem->bus.base = dev_priv->gart_info.aper_base;
+			mem->bus.is_iomem = true;
+		}
+#endif
+		break;
+	case TTM_PL_VRAM:
+		mem->bus.offset = mem->mm_node->start << PAGE_SHIFT;
+		mem->bus.base = drm_get_resource_start(dev, 1);
+		mem->bus.is_iomem = true;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void
+nouveau_ttm_io_mem_free(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
+{
+}
+
+static int
+nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo)
+{
+	return 0;
+}
+
 struct ttm_bo_driver nouveau_bo_driver = {
 	.create_ttm_backend_entry = nouveau_bo_create_ttm_backend_entry,
 	.invalidate_caches = nouveau_bo_invalidate_caches,
@@ -773,5 +820,8 @@ struct ttm_bo_driver nouveau_bo_driver = {
 	.sync_obj_flush = nouveau_fence_flush,
 	.sync_obj_unref = nouveau_fence_unref,
 	.sync_obj_ref = nouveau_fence_ref,
+	.fault_reserve_notify = &nouveau_ttm_fault_reserve_notify,
+	.io_mem_reserve = &nouveau_ttm_io_mem_reserve,
+	.io_mem_free = &nouveau_ttm_io_mem_free,
 };