ping for review

Am 24.06.21 um 11:53 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 xen functions are being removed. The file_operations
> structure fops is now being created by the helper macro
> DEFINE_DRM_GEM_FOPS().
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/xen/xen_drm_front.c     |  16 +---
>   drivers/gpu/drm/xen/xen_drm_front_gem.c | 108 +++++++++---------------
>   drivers/gpu/drm/xen/xen_drm_front_gem.h |   7 --
>   3 files changed, 44 insertions(+), 87 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
> index 9f14d99c763c..434064c820e8 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front.c
> @@ -469,19 +469,7 @@ static void xen_drm_drv_release(struct drm_device *dev)
>   	kfree(drm_info);
>   }
>   
> -static const struct file_operations xen_drm_dev_fops = {
> -	.owner          = THIS_MODULE,
> -	.open           = drm_open,
> -	.release        = drm_release,
> -	.unlocked_ioctl = drm_ioctl,
> -#ifdef CONFIG_COMPAT
> -	.compat_ioctl   = drm_compat_ioctl,
> -#endif
> -	.poll           = drm_poll,
> -	.read           = drm_read,
> -	.llseek         = no_llseek,
> -	.mmap           = xen_drm_front_gem_mmap,
> -};
> +DEFINE_DRM_GEM_FOPS(xen_drm_dev_fops);
>   
>   static const struct drm_driver xen_drm_driver = {
>   	.driver_features           = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
> @@ -489,7 +477,7 @@ static const struct drm_driver xen_drm_driver = {
>   	.prime_handle_to_fd        = drm_gem_prime_handle_to_fd,
>   	.prime_fd_to_handle        = drm_gem_prime_fd_to_handle,
>   	.gem_prime_import_sg_table = xen_drm_front_gem_import_sg_table,
> -	.gem_prime_mmap            = xen_drm_front_gem_prime_mmap,
> +	.gem_prime_mmap            = drm_gem_prime_mmap,
>   	.dumb_create               = xen_drm_drv_dumb_create,
>   	.fops                      = &xen_drm_dev_fops,
>   	.name                      = "xendrm-du",
> diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> index b293c67230ef..dd358ba2bf8e 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> @@ -57,6 +57,47 @@ static void gem_free_pages_array(struct xen_gem_object *xen_obj)
>   	xen_obj->pages = NULL;
>   }
>   
> +static int xen_drm_front_gem_object_mmap(struct drm_gem_object *gem_obj,
> +					 struct vm_area_struct *vma)
> +{
> +	struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);
> +	int ret;
> +
> +	vma->vm_ops = gem_obj->funcs->vm_ops;
> +
> +	/*
> +	 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
> +	 * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
> +	 * the whole buffer.
> +	 */
> +	vma->vm_flags &= ~VM_PFNMAP;
> +	vma->vm_flags |= VM_MIXEDMAP;
> +	vma->vm_pgoff = 0;
> +
> +	/*
> +	 * According to Xen on ARM ABI (xen/include/public/arch-arm.h):
> +	 * all memory which is shared with other entities in the system
> +	 * (including the hypervisor and other guests) must reside in memory
> +	 * which is mapped as Normal Inner Write-Back Outer Write-Back
> +	 * Inner-Shareable.
> +	 */
> +	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
> +
> +	/*
> +	 * vm_operations_struct.fault handler will be called if CPU access
> +	 * to VM is here. For GPUs this isn't the case, because CPU  doesn't
> +	 * touch the memory. Insert pages now, so both CPU and GPU are happy.
> +	 *
> +	 * FIXME: as we insert all the pages now then no .fault handler must
> +	 * be called, so don't provide one
> +	 */
> +	ret = vm_map_pages(vma, xen_obj->pages, xen_obj->num_pages);
> +	if (ret < 0)
> +		DRM_ERROR("Failed to map pages into vma: %d\n", ret);
> +
> +	return ret;
> +}
> +
>   static const struct vm_operations_struct xen_drm_drv_vm_ops = {
>   	.open           = drm_gem_vm_open,
>   	.close          = drm_gem_vm_close,
> @@ -67,6 +108,7 @@ static const struct drm_gem_object_funcs xen_drm_front_gem_object_funcs = {
>   	.get_sg_table = xen_drm_front_gem_get_sg_table,
>   	.vmap = xen_drm_front_gem_prime_vmap,
>   	.vunmap = xen_drm_front_gem_prime_vunmap,
> +	.mmap = xen_drm_front_gem_object_mmap,
>   	.vm_ops = &xen_drm_drv_vm_ops,
>   };
>   
> @@ -238,58 +280,6 @@ xen_drm_front_gem_import_sg_table(struct drm_device *dev,
>   	return &xen_obj->base;
>   }
>   
> -static int gem_mmap_obj(struct xen_gem_object *xen_obj,
> -			struct vm_area_struct *vma)
> -{
> -	int ret;
> -
> -	/*
> -	 * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
> -	 * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
> -	 * the whole buffer.
> -	 */
> -	vma->vm_flags &= ~VM_PFNMAP;
> -	vma->vm_flags |= VM_MIXEDMAP;
> -	vma->vm_pgoff = 0;
> -	/*
> -	 * According to Xen on ARM ABI (xen/include/public/arch-arm.h):
> -	 * all memory which is shared with other entities in the system
> -	 * (including the hypervisor and other guests) must reside in memory
> -	 * which is mapped as Normal Inner Write-Back Outer Write-Back
> -	 * Inner-Shareable.
> -	 */
> -	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
> -
> -	/*
> -	 * vm_operations_struct.fault handler will be called if CPU access
> -	 * to VM is here. For GPUs this isn't the case, because CPU
> -	 * doesn't touch the memory. Insert pages now, so both CPU and GPU are
> -	 * happy.
> -	 * FIXME: as we insert all the pages now then no .fault handler must
> -	 * be called, so don't provide one
> -	 */
> -	ret = vm_map_pages(vma, xen_obj->pages, xen_obj->num_pages);
> -	if (ret < 0)
> -		DRM_ERROR("Failed to map pages into vma: %d\n", ret);
> -
> -	return ret;
> -}
> -
> -int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)
> -{
> -	struct xen_gem_object *xen_obj;
> -	struct drm_gem_object *gem_obj;
> -	int ret;
> -
> -	ret = drm_gem_mmap(filp, vma);
> -	if (ret < 0)
> -		return ret;
> -
> -	gem_obj = vma->vm_private_data;
> -	xen_obj = to_xen_gem_obj(gem_obj);
> -	return gem_mmap_obj(xen_obj, vma);
> -}
> -
>   int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj, struct dma_buf_map *map)
>   {
>   	struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);
> @@ -313,17 +303,3 @@ void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
>   {
>   	vunmap(map->vaddr);
>   }
> -
> -int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
> -				 struct vm_area_struct *vma)
> -{
> -	struct xen_gem_object *xen_obj;
> -	int ret;
> -
> -	ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma);
> -	if (ret < 0)
> -		return ret;
> -
> -	xen_obj = to_xen_gem_obj(gem_obj);
> -	return gem_mmap_obj(xen_obj, vma);
> -}
> diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.h b/drivers/gpu/drm/xen/xen_drm_front_gem.h
> index a4e67d0a149c..eaea470f7001 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front_gem.h
> +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.h
> @@ -15,9 +15,7 @@ struct dma_buf_attachment;
>   struct dma_buf_map;
>   struct drm_device;
>   struct drm_gem_object;
> -struct file;
>   struct sg_table;
> -struct vm_area_struct;
>   
>   struct drm_gem_object *xen_drm_front_gem_create(struct drm_device *dev,
>   						size_t size);
> @@ -33,15 +31,10 @@ struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *obj);
>   
>   void xen_drm_front_gem_free_object_unlocked(struct drm_gem_object *gem_obj);
>   
> -int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma);
> -
>   int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj,
>   				 struct dma_buf_map *map);
>   
>   void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
>   				    struct dma_buf_map *map);
>   
> -int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
> -				 struct vm_area_struct *vma);
> -
>   #endif /* __XEN_DRM_FRONT_GEM_H */
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer