drm/etnaviv: split out iova search and MMU reaping logic

With MMUv2 the command buffers need to be mapped through the MMU.
Split out the iova search and MMU reaping logic so it can be reused
for the cmdbuf mapping, where no GEM object is involved.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_mmu.c

@@ -103,41 +103,21 @@ static void etnaviv_iommu_remove_mapping(struct etnaviv_iommu *mmu,
 	drm_mm_remove_node(&mapping->vram_node);
 }
 
-int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
-	struct etnaviv_gem_object *etnaviv_obj, u32 memory_base,
-	struct etnaviv_vram_mapping *mapping)
+static int etnaviv_iommu_find_iova(struct etnaviv_iommu *mmu,
+				   struct drm_mm_node *node, size_t size)
 {
 	struct etnaviv_vram_mapping *free = NULL;
-	struct sg_table *sgt = etnaviv_obj->sgt;
-	struct drm_mm_node *node;
 	int ret;
 
-	lockdep_assert_held(&etnaviv_obj->lock);
-
-	mutex_lock(&mmu->lock);
+	lockdep_assert_held(&mmu->lock);
 
-	/* v1 MMU can optimize single entry (contiguous) scatterlists */
-	if (mmu->version == ETNAVIV_IOMMU_V1 &&
-	    sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
-		u32 iova;
-
-		iova = sg_dma_address(sgt->sgl) - memory_base;
-		if (iova < 0x80000000 - sg_dma_len(sgt->sgl)) {
-			mapping->iova = iova;
-			list_add_tail(&mapping->mmu_node, &mmu->mappings);
-			mutex_unlock(&mmu->lock);
-			return 0;
-		}
-	}
-
-	node = &mapping->vram_node;
 	while (1) {
 		struct etnaviv_vram_mapping *m, *n;
 		struct list_head list;
 		bool found;
 
 		ret = drm_mm_insert_node_in_range(&mmu->mm, node,
-			etnaviv_obj->base.size, 0, mmu->last_iova, ~0UL,
+			size, 0, mmu->last_iova, ~0UL,
 			DRM_MM_SEARCH_DEFAULT);
 
 		if (ret != -ENOSPC)
@@ -154,7 +134,7 @@ int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
 		}
 
 		/* Try to retire some entries */
-		drm_mm_init_scan(&mmu->mm, etnaviv_obj->base.size, 0, 0);
+		drm_mm_init_scan(&mmu->mm, size, 0, 0);
 
 		found = 0;
 		INIT_LIST_HEAD(&list);
@@ -215,6 +195,38 @@ int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
 		mmu->need_flush = true;
 	}
 
+	return ret;
+}
+
+int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
+	struct etnaviv_gem_object *etnaviv_obj, u32 memory_base,
+	struct etnaviv_vram_mapping *mapping)
+{
+	struct sg_table *sgt = etnaviv_obj->sgt;
+	struct drm_mm_node *node;
+	int ret;
+
+	lockdep_assert_held(&etnaviv_obj->lock);
+
+	mutex_lock(&mmu->lock);
+
+	/* v1 MMU can optimize single entry (contiguous) scatterlists */
+	if (mmu->version == ETNAVIV_IOMMU_V1 &&
+	    sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
+		u32 iova;
+
+		iova = sg_dma_address(sgt->sgl) - memory_base;
+		if (iova < 0x80000000 - sg_dma_len(sgt->sgl)) {
+			mapping->iova = iova;
+			list_add_tail(&mapping->mmu_node, &mmu->mappings);
+			mutex_unlock(&mmu->lock);
+			return 0;
+		}
+	}
+
+	node = &mapping->vram_node;
+
+	ret = etnaviv_iommu_find_iova(mmu, node, etnaviv_obj->base.size);
 	if (ret < 0) {
 		mutex_unlock(&mmu->lock);
 		return ret;