drm: etnaviv: clean up vram_mapping submission/retire path

Currently, we scan the list of mappings each time we want to operate on
the vram_mapping struct.  Rather than repeatedly scanning these, look
them up once in the submission path, and then use _reference and
_unreference methods as necessary to manage this object.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_drv.h

@@ -75,9 +75,6 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 int etnaviv_gem_mmap(struct file *filp, struct vm_area_struct *vma);
 int etnaviv_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
 int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, u64 *offset);
-int etnaviv_gem_get_iova(struct etnaviv_gpu *gpu,
-	struct drm_gem_object *obj, u32 *iova);
-void etnaviv_gem_put_iova(struct etnaviv_gpu *gpu, struct drm_gem_object *obj);
 struct sg_table *etnaviv_gem_prime_get_sg_table(struct drm_gem_object *obj);
 void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj);
 void etnaviv_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);

drivers/gpu/drm/etnaviv/etnaviv_gem.c

@@ -260,8 +260,32 @@ etnaviv_gem_get_vram_mapping(struct etnaviv_gem_object *obj,
 	return NULL;
 }
 
-int etnaviv_gem_get_iova(struct etnaviv_gpu *gpu,
-	struct drm_gem_object *obj, u32 *iova)
+void etnaviv_gem_mapping_reference(struct etnaviv_vram_mapping *mapping)
+{
+	struct etnaviv_gem_object *etnaviv_obj = mapping->object;
+
+	drm_gem_object_reference(&etnaviv_obj->base);
+
+	mutex_lock(&etnaviv_obj->lock);
+	WARN_ON(mapping->use == 0);
+	mapping->use += 1;
+	mutex_unlock(&etnaviv_obj->lock);
+}
+
+void etnaviv_gem_mapping_unreference(struct etnaviv_vram_mapping *mapping)
+{
+	struct etnaviv_gem_object *etnaviv_obj = mapping->object;
+
+	mutex_lock(&etnaviv_obj->lock);
+	WARN_ON(mapping->use == 0);
+	mapping->use -= 1;
+	mutex_unlock(&etnaviv_obj->lock);
+
+	drm_gem_object_unreference_unlocked(&etnaviv_obj->base);
+}
+
+struct etnaviv_vram_mapping *etnaviv_gem_mapping_get(
+	struct drm_gem_object *obj, struct etnaviv_gpu *gpu)
 {
 	struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj);
 	struct etnaviv_vram_mapping *mapping;
@@ -329,28 +353,12 @@ int etnaviv_gem_get_iova(struct etnaviv_gpu *gpu,
 out:
 	mutex_unlock(&etnaviv_obj->lock);
 
-	if (!ret) {
-		/* Take a reference on the object */
-		drm_gem_object_reference(obj);
-		*iova = mapping->iova;
-	}
-
-	return ret;
-}
-
-void etnaviv_gem_put_iova(struct etnaviv_gpu *gpu, struct drm_gem_object *obj)
-{
-	struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj);
-	struct etnaviv_vram_mapping *mapping;
-
-	mutex_lock(&etnaviv_obj->lock);
-	mapping = etnaviv_gem_get_vram_mapping(etnaviv_obj, gpu->mmu);
-
-	WARN_ON(mapping->use == 0);
-	mapping->use -= 1;
-	mutex_unlock(&etnaviv_obj->lock);
+	if (ret)
+		return ERR_PTR(ret);
 
-	drm_gem_object_unreference_unlocked(obj);
+	/* Take a reference on the object */
+	drm_gem_object_reference(obj);
+	return mapping;
 }
 
 void *etnaviv_gem_vmap(struct drm_gem_object *obj)

drivers/gpu/drm/etnaviv/etnaviv_gem.h

@@ -102,6 +102,7 @@ struct etnaviv_gem_submit {
 	struct {
 		u32 flags;
 		struct etnaviv_gem_object *obj;
+		struct etnaviv_vram_mapping *mapping;
 		u32 iova;
 	} bos[0];
 };
@@ -115,4 +116,9 @@ int etnaviv_gem_obj_add(struct drm_device *dev, struct drm_gem_object *obj);
 struct page **etnaviv_gem_get_pages(struct etnaviv_gem_object *obj);
 void etnaviv_gem_put_pages(struct etnaviv_gem_object *obj);
 
+struct etnaviv_vram_mapping *etnaviv_gem_mapping_get(
+	struct drm_gem_object *obj, struct etnaviv_gpu *gpu);
+void etnaviv_gem_mapping_reference(struct etnaviv_vram_mapping *mapping);
+void etnaviv_gem_mapping_unreference(struct etnaviv_vram_mapping *mapping);
+
 #endif /* __ETNAVIV_GEM_H__ */

drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c

@@ -187,12 +187,11 @@ static void submit_unpin_objects(struct etnaviv_gem_submit *submit)
 	int i;
 
 	for (i = 0; i < submit->nr_bos; i++) {
-		struct etnaviv_gem_object *etnaviv_obj = submit->bos[i].obj;
-
 		if (submit->bos[i].flags & BO_PINNED)
-			etnaviv_gem_put_iova(submit->gpu, &etnaviv_obj->base);
+			etnaviv_gem_mapping_unreference(submit->bos[i].mapping);
 
 		submit->bos[i].iova = 0;
+		submit->bos[i].mapping = NULL;
 		submit->bos[i].flags &= ~BO_PINNED;
 	}
 }
@@ -203,15 +202,18 @@ static int submit_pin_objects(struct etnaviv_gem_submit *submit)
 
 	for (i = 0; i < submit->nr_bos; i++) {
 		struct etnaviv_gem_object *etnaviv_obj = submit->bos[i].obj;
-		u32 iova;
+		struct etnaviv_vram_mapping *mapping;
 
-		ret = etnaviv_gem_get_iova(submit->gpu, &etnaviv_obj->base,
-					   &iova);
-		if (ret)
+		mapping = etnaviv_gem_mapping_get(&etnaviv_obj->base,
+						  submit->gpu);
+		if (IS_ERR(mapping)) {
+			ret = PTR_ERR(mapping);
 			break;
+		}
 
 		submit->bos[i].flags |= BO_PINNED;
-		submit->bos[i].iova = iova;
+		submit->bos[i].mapping = mapping;
+		submit->bos[i].iova = mapping->iova;
 	}
 
 	return ret;

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -1103,7 +1103,7 @@ struct etnaviv_cmdbuf *etnaviv_gpu_cmdbuf_new(struct etnaviv_gpu *gpu, u32 size,
 	size_t nr_bos)
 {
 	struct etnaviv_cmdbuf *cmdbuf;
-	size_t sz = size_vstruct(nr_bos, sizeof(cmdbuf->bo[0]),
+	size_t sz = size_vstruct(nr_bos, sizeof(cmdbuf->bo_map[0]),
 				 sizeof(*cmdbuf));
 
 	cmdbuf = kzalloc(sz, GFP_KERNEL);
@@ -1147,11 +1147,12 @@ static void retire_worker(struct work_struct *work)
 		fence_put(cmdbuf->fence);
 
 		for (i = 0; i < cmdbuf->nr_bos; i++) {
-			struct etnaviv_gem_object *etnaviv_obj = cmdbuf->bo[i];
+			struct etnaviv_vram_mapping *mapping = cmdbuf->bo_map[i];
+			struct etnaviv_gem_object *etnaviv_obj = mapping->object;
 
 			atomic_dec(&etnaviv_obj->gpu_active);
 			/* drop the refcount taken in etnaviv_gpu_submit */
-			etnaviv_gem_put_iova(gpu, &etnaviv_obj->base);
+			etnaviv_gem_mapping_unreference(mapping);
 		}
 
 		etnaviv_gpu_cmdbuf_free(cmdbuf);
@@ -1309,11 +1310,10 @@ int etnaviv_gpu_submit(struct etnaviv_gpu *gpu,
 
 	for (i = 0; i < submit->nr_bos; i++) {
 		struct etnaviv_gem_object *etnaviv_obj = submit->bos[i].obj;
-		u32 iova;
 
-		/* Each cmdbuf takes a refcount on the iova */
-		etnaviv_gem_get_iova(gpu, &etnaviv_obj->base, &iova);
-		cmdbuf->bo[i] = etnaviv_obj;
+		/* Each cmdbuf takes a refcount on the mapping */
+		etnaviv_gem_mapping_reference(submit->bos[i].mapping);
+		cmdbuf->bo_map[i] = submit->bos[i].mapping;
 		atomic_inc(&etnaviv_obj->gpu_active);
 
 		if (submit->bos[i].flags & ETNA_SUBMIT_BO_WRITE)

drivers/gpu/drm/etnaviv/etnaviv_gpu.h

@@ -23,6 +23,7 @@
 #include "etnaviv_drv.h"
 
 struct etnaviv_gem_submit;
+struct etnaviv_vram_mapping;
 
 struct etnaviv_chip_identity {
 	/* Chip model. */
@@ -167,7 +168,7 @@ struct etnaviv_cmdbuf {
 	struct list_head node;
 	/* BOs attached to this command buffer */
 	unsigned int nr_bos;
-	struct etnaviv_gem_object *bo[0];
+	struct etnaviv_vram_mapping *bo_map[0];
 };
 
 static inline void gpu_write(struct etnaviv_gpu *gpu, u32 reg, u32 data)

drivers/gpu/drm/etnaviv/etnaviv_mmu.c

@@ -193,7 +193,7 @@ int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
 
 		/*
 		 * Unmap the blocks which need to be reaped from the MMU.
-		 * Clear the mmu pointer to prevent the get_iova finding
+		 * Clear the mmu pointer to prevent the mapping_get finding
 		 * this mapping.
 		 */
 		list_for_each_entry_safe(m, n, &list, scan_node) {