drm/msm/gem: Rework vma lookup and pin

Combines duplicate vma lookup in the get_and_pin path.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://lore.kernel.org/r/20220411215849.297838-8-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/msm_gem.c

@@ -376,39 +376,40 @@ put_iova_vmas(struct drm_gem_object *obj)
 	}
 }
 
-static int get_iova_locked(struct drm_gem_object *obj,
-		struct msm_gem_address_space *aspace, uint64_t *iova,
+static struct msm_gem_vma *get_vma_locked(struct drm_gem_object *obj,
+		struct msm_gem_address_space *aspace,
 		u64 range_start, u64 range_end)
 {
 	struct msm_gem_vma *vma;
-	int ret = 0;
 
 	GEM_WARN_ON(!msm_gem_is_locked(obj));
 
 	vma = lookup_vma(obj, aspace);
 
 	if (!vma) {
+		int ret;
+
 		vma = add_vma(obj, aspace);
 		if (IS_ERR(vma))
-			return PTR_ERR(vma);
+			return vma;
 
 		ret = msm_gem_init_vma(aspace, vma, obj->size,
 			range_start, range_end);
 		if (ret) {
 			del_vma(vma);
-			return ret;
+			return ERR_PTR(ret);
 		}
+	} else {
+		GEM_WARN_ON(vma->iova < range_start);
+		GEM_WARN_ON((vma->iova + obj->size) > range_end);
 	}
 
-	*iova = vma->iova;
-	return 0;
+	return vma;
 }
 
-static int msm_gem_pin_iova(struct drm_gem_object *obj,
-		struct msm_gem_address_space *aspace)
+static int msm_gem_pin_iova(struct drm_gem_object *obj, struct msm_gem_vma *vma)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
-	struct msm_gem_vma *vma;
 	struct page **pages;
 	int ret, prot = IOMMU_READ;
 
@@ -426,15 +427,11 @@ static int msm_gem_pin_iova(struct drm_gem_object *obj,
 	if (GEM_WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED))
 		return -EBUSY;
 
-	vma = lookup_vma(obj, aspace);
-	if (GEM_WARN_ON(!vma))
-		return -EINVAL;
-
 	pages = get_pages(obj);
 	if (IS_ERR(pages))
 		return PTR_ERR(pages);
 
-	ret = msm_gem_map_vma(aspace, vma, prot, msm_obj->sgt, obj->size);
+	ret = msm_gem_map_vma(vma->aspace, vma, prot, msm_obj->sgt, obj->size);
 
 	if (!ret)
 		msm_obj->pin_count++;
@@ -446,19 +443,18 @@ static int get_and_pin_iova_range_locked(struct drm_gem_object *obj,
 		struct msm_gem_address_space *aspace, uint64_t *iova,
 		u64 range_start, u64 range_end)
 {
-	u64 local;
+	struct msm_gem_vma *vma;
 	int ret;
 
 	GEM_WARN_ON(!msm_gem_is_locked(obj));
 
-	ret = get_iova_locked(obj, aspace, &local,
-		range_start, range_end);
-
-	if (!ret)
-		ret = msm_gem_pin_iova(obj, aspace);
+	vma = get_vma_locked(obj, aspace, range_start, range_end);
+	if (IS_ERR(vma))
+		return PTR_ERR(vma);
 
+	ret = msm_gem_pin_iova(obj, vma);
 	if (!ret)
-		*iova = local;
+		*iova = vma->iova;
 
 	return ret;
 }
@@ -500,10 +496,16 @@ int msm_gem_get_and_pin_iova(struct drm_gem_object *obj,
 int msm_gem_get_iova(struct drm_gem_object *obj,
 		struct msm_gem_address_space *aspace, uint64_t *iova)
 {
-	int ret;
+	struct msm_gem_vma *vma;
+	int ret = 0;
 
 	msm_gem_lock(obj);
-	ret = get_iova_locked(obj, aspace, iova, 0, U64_MAX);
+	vma = get_vma_locked(obj, aspace, 0, U64_MAX);
+	if (IS_ERR(vma)) {
+		ret = PTR_ERR(vma);
+	} else {
+		*iova = vma->iova;
+	}
 	msm_gem_unlock(obj);
 
 	return ret;