drm/udl: Use GEM vmap/mmap function from SHMEM helpers

The udl driver contains an implementation of GEM vmap and mmap
operations that is identical to the common SHMEM helper; except
that udl's code uses cached pages by default.

Convert udl to regular SHMEM helper functions. There's no reason
to have udl behave differently from all other SHMEM drivers. The
udl driver uses the SHMEM helper to enable caching.

v3:
	* rebased onto Daniel's shmem untangle series
v2:
	* implement .gem_create_object with SHMEM helper
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200609090820.20256-3-tzimmermann@suse.de

drivers/gpu/drm/udl/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
-udl-y := udl_drv.o udl_modeset.o udl_connector.o udl_main.o udl_transfer.o udl_gem.o
+udl-y := udl_drv.o udl_modeset.o udl_connector.o udl_main.o udl_transfer.o
 
 obj-$(CONFIG_DRM_UDL) := udl.o

drivers/gpu/drm/udl/udl_drv.c

@@ -37,8 +37,8 @@ DEFINE_DRM_GEM_FOPS(udl_driver_fops);
 static struct drm_driver driver = {
 	.driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
 
-	/* gem hooks */
-	.gem_create_object = udl_driver_gem_create_object,
+	/* GEM hooks */
+	.gem_create_object = drm_gem_shmem_create_object_cached,
 
 	.fops = &udl_driver_fops,
 	DRM_GEM_SHMEM_DRIVER_OPS,

drivers/gpu/drm/udl/udl_drv.h

@@ -81,9 +81,6 @@ int udl_render_hline(struct drm_device *dev, int log_bpp, struct urb **urb_ptr,
 		     const char *front, char **urb_buf_ptr,
 		     u32 byte_offset, u32 device_byte_offset, u32 byte_width);
 
-struct drm_gem_object *udl_driver_gem_create_object(struct drm_device *dev,
-						    size_t size);
-
 int udl_drop_usb(struct drm_device *dev);
 
 #define CMD_WRITE_RAW8   "\xAF\x60" /**< 8 bit raw write command. */

drivers/gpu/drm/udl/udl_gem.c

-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2012 Red Hat
- */
-
-#include <linux/dma-buf.h>
-#include <linux/vmalloc.h>
-
-#include <drm/drm_drv.h>
-#include <drm/drm_gem_shmem_helper.h>
-#include <drm/drm_mode.h>
-#include <drm/drm_prime.h>
-
-#include "udl_drv.h"
-
-/*
- * 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;
-
-	if (obj->import_attach) {
-		shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);
-	} else {
-		ret = drm_gem_shmem_get_pages(shmem);
-		if (ret)
-			goto err;
-
-		shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
-				    VM_MAP, PAGE_KERNEL);
-
-		if (!shmem->vaddr)
-			drm_gem_shmem_put_pages(shmem);
-	}
-
-	if (!shmem->vaddr) {
-		DRM_DEBUG_KMS("Failed to vmap pages\n");
-		ret = -ENOMEM;
-		goto err;
-	}
-
-out:
-	mutex_unlock(&shmem->vmap_lock);
-	return shmem->vaddr;
-
-err:
-	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,
-	.vunmap = drm_gem_shmem_vunmap,
-	.mmap = udl_gem_object_mmap,
-};
-
-/*
- * Helpers for struct drm_driver
- */
-
-struct drm_gem_object *udl_driver_gem_create_object(struct drm_device *dev,
-						    size_t size)
-{
-	struct drm_gem_shmem_object *shmem;
-	struct drm_gem_object *obj;
-
-	shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
-	if (!shmem)
-		return NULL;
-
-	obj = &shmem->base;
-	obj->funcs = &udl_gem_object_funcs;
-
-	return obj;
-}