linux-kernel - [PATCH v5 3/3] drm/udl: simplify gem object mapping.

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Date:   Wed, 26 Feb 2020 16:47:52 +0100
From:   Gerd Hoffmann <kraxel@...hat.com>
To:     dri-devel@...ts.freedesktop.org
Cc:     tzimmermann@...e.de, gurchetansingh@...omium.org,
        olvaffe@...il.com, Guillaume.Gardet@....com,
        Gerd Hoffmann <kraxel@...hat.com>,
        Dave Airlie <airlied@...hat.com>, Sean Paul <sean@...rly.run>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Sumit Semwal <sumit.semwal@...aro.org>,
        linux-kernel@...r.kernel.org (open list),
        linux-media@...r.kernel.org (open list:DMA BUFFER SHARING FRAMEWORK),
        linaro-mm-sig@...ts.linaro.org (moderated list:DMA BUFFER SHARING
        FRAMEWORK)
Subject: [PATCH v5 3/3] drm/udl: simplify gem object mapping.

With shmem helpers allowing to update pgprot caching flags via
drm_gem_shmem_object.map_cached we can just use that and ditch
our own implementations of mmap() and vmap().

We also don't need a special case for imported objects, any map
requests are handled by the exporter not udl.

Signed-off-by: Gerd Hoffmann <kraxel@...hat.com>
---
 drivers/gpu/drm/udl/udl_gem.c | 62 ++---------------------------------
 1 file changed, 3 insertions(+), 59 deletions(-)

diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
index b6e26f98aa0a..7e3a88b25b6b 100644
--- a/drivers/gpu/drm/udl/udl_gem.c
+++ b/drivers/gpu/drm/udl/udl_gem.c
@@ -17,72 +17,15 @@
  * GEM object funcs
  */
 
-static int udl_gem_object_mmap(struct drm_gem_object *obj,
-			       struct vm_area_struct *vma)
-{
-	int ret;
-
-	ret = drm_gem_shmem_mmap(obj, vma);
-	if (ret)
-		return ret;
-
-	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-	if (obj->import_attach)
-		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
-	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
-
-	return 0;
-}
-
-static void *udl_gem_object_vmap(struct drm_gem_object *obj)
-{
-	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
-	int ret;
-
-	ret = mutex_lock_interruptible(&shmem->vmap_lock);
-	if (ret)
-		return ERR_PTR(ret);
-
-	if (shmem->vmap_use_count++ > 0)
-		goto out;
-
-	ret = drm_gem_shmem_get_pages(shmem);
-	if (ret)
-		goto err_zero_use;
-
-	if (obj->import_attach)
-		shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);
-	else
-		shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
-				    VM_MAP, PAGE_KERNEL);
-
-	if (!shmem->vaddr) {
-		DRM_DEBUG_KMS("Failed to vmap pages\n");
-		ret = -ENOMEM;
-		goto err_put_pages;
-	}
-
-out:
-	mutex_unlock(&shmem->vmap_lock);
-	return shmem->vaddr;
-
-err_put_pages:
-	drm_gem_shmem_put_pages(shmem);
-err_zero_use:
-	shmem->vmap_use_count = 0;
-	mutex_unlock(&shmem->vmap_lock);
-	return ERR_PTR(ret);
-}
-
 static const struct drm_gem_object_funcs udl_gem_object_funcs = {
 	.free = drm_gem_shmem_free_object,
 	.print_info = drm_gem_shmem_print_info,
 	.pin = drm_gem_shmem_pin,
 	.unpin = drm_gem_shmem_unpin,
 	.get_sg_table = drm_gem_shmem_get_sg_table,
-	.vmap = udl_gem_object_vmap,
+	.vmap = drm_gem_shmem_vmap,
 	.vunmap = drm_gem_shmem_vunmap,
-	.mmap = udl_gem_object_mmap,
+	.mmap = drm_gem_shmem_mmap,
 };
 
 /*
@@ -101,6 +44,7 @@ struct drm_gem_object *udl_driver_gem_create_object(struct drm_device *dev,
 
 	obj = &shmem->base;
 	obj->funcs = &udl_gem_object_funcs;
+	shmem->map_cached = true;
 
 	return obj;
 }
-- 
2.18.2