Re: [PATCH] drm/vgem: Implement mmap as GEM object function

[Christian König <christian.koenig@xxxxxxx>]

Am 24.06.21 um 11:52 schrieb Thomas Zimmermann:
> Moving the driver-specific mmap code into a GEM object function allows
> for using DRM helpers for various mmap callbacks.
>
> The respective vgem functions are being removed. The file_operations
> structure vgem_driver_fops is now being created by the helper macro
> DEFINE_DRM_GEM_FOPS().
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

Acked-by: Christian König <christian.koenig@xxxxxxx>

> ---
>   drivers/gpu/drm/vgem/vgem_drv.c | 46 ++++-----------------------------
>   1 file changed, 5 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
> index bf38a7e319d1..df634aa52638 100644
> --- a/drivers/gpu/drm/vgem/vgem_drv.c
> +++ b/drivers/gpu/drm/vgem/vgem_drv.c
> @@ -239,32 +239,7 @@ static struct drm_ioctl_desc vgem_ioctls[] = {
>   	DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_RENDER_ALLOW),
>   };
>   
> -static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
> -{
> -	unsigned long flags = vma->vm_flags;
> -	int ret;
> -
> -	ret = drm_gem_mmap(filp, vma);
> -	if (ret)
> -		return ret;
> -
> -	/* Keep the WC mmaping set by drm_gem_mmap() but our pages
> -	 * are ordinary and not special.
> -	 */
> -	vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
> -	return 0;
> -}
> -
> -static const struct file_operations vgem_driver_fops = {
> -	.owner		= THIS_MODULE,
> -	.open		= drm_open,
> -	.mmap		= vgem_mmap,
> -	.poll		= drm_poll,
> -	.read		= drm_read,
> -	.unlocked_ioctl = drm_ioctl,
> -	.compat_ioctl	= drm_compat_ioctl,
> -	.release	= drm_release,
> -};
> +DEFINE_DRM_GEM_FOPS(vgem_driver_fops);
>   
>   static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
>   {
> @@ -387,24 +362,12 @@ static void vgem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map *ma
>   	vgem_unpin_pages(bo);
>   }
>   
> -static int vgem_prime_mmap(struct drm_gem_object *obj,
> -			   struct vm_area_struct *vma)
> +static int vgem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
>   {
> -	int ret;
> -
> -	if (obj->size < vma->vm_end - vma->vm_start)
> -		return -EINVAL;
> -
> -	if (!obj->filp)
> -		return -ENODEV;
> -
> -	ret = call_mmap(obj->filp, vma);
> -	if (ret)
> -		return ret;
> -
>   	vma_set_file(vma, obj->filp);
>   	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
>   	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
> +	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
>   
>   	return 0;
>   }
> @@ -416,6 +379,7 @@ static const struct drm_gem_object_funcs vgem_gem_object_funcs = {
>   	.get_sg_table = vgem_prime_get_sg_table,
>   	.vmap = vgem_prime_vmap,
>   	.vunmap = vgem_prime_vunmap,
> +	.mmap = vgem_prime_mmap,
>   	.vm_ops = &vgem_gem_vm_ops,
>   };
>   
> @@ -433,7 +397,7 @@ static const struct drm_driver vgem_driver = {
>   	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
>   	.gem_prime_import = vgem_prime_import,
>   	.gem_prime_import_sg_table = vgem_prime_import_sg_table,
> -	.gem_prime_mmap = vgem_prime_mmap,
> +	.gem_prime_mmap = drm_gem_prime_mmap,
>   
>   	.name	= DRIVER_NAME,
>   	.desc	= DRIVER_DESC,