Re: [PATCH 4/9] drm/ttm: Allow the driver to provide the ttm struct vm_operations_struct

[Koenig, Christian]

Am 12.04.19 um 18:04 schrieb Thomas Hellstrom:
> Add a pointer to the struct vm_operations_struct in the bo_device, and
> assign that pointer to the default value currently used.
>
> The driver can then optionally modify that pointer and the new value
> can be used for each new vma created.
>
> Cc: "Christian KÃnig" <christian.koenig@xxxxxxx>
> Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>

Yes, please. This way we can also finally cleanup the VM operations hack 
we use in radeon and maybe still even amdgpu.

Reviewed-by: Christian KÃnig <christian.koenig@xxxxxxx>

> ---
>   drivers/gpu/drm/ttm/ttm_bo.c    | 1 +
>   drivers/gpu/drm/ttm/ttm_bo_vm.c | 6 +++---
>   include/drm/ttm/ttm_bo_driver.h | 6 ++++++
>   3 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 3f56647cdb35..1c85bec00472 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -1656,6 +1656,7 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
>   	mutex_lock(&ttm_global_mutex);
>   	list_add_tail(&bdev->device_list, &glob->device_list);
>   	mutex_unlock(&ttm_global_mutex);
> +	bdev->vm_ops = &ttm_bo_vm_ops;
>   
>   	return 0;
>   out_no_sys:
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> index e86a29a1e51f..bfb25b81fed7 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> @@ -395,7 +395,7 @@ static int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
>   	return ret;
>   }
>   
> -static const struct vm_operations_struct ttm_bo_vm_ops = {
> +const struct vm_operations_struct ttm_bo_vm_ops = {
>   	.fault = ttm_bo_vm_fault,
>   	.open = ttm_bo_vm_open,
>   	.close = ttm_bo_vm_close,
> @@ -445,7 +445,7 @@ int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
>   	if (unlikely(ret != 0))
>   		goto out_unref;
>   
> -	vma->vm_ops = &ttm_bo_vm_ops;
> +	vma->vm_ops = bdev->vm_ops;
>   
>   	/*
>   	 * Note: We're transferring the bo reference to
> @@ -477,7 +477,7 @@ int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
>   
>   	ttm_bo_get(bo);
>   
> -	vma->vm_ops = &ttm_bo_vm_ops;
> +	vma->vm_ops = bo->bdev->vm_ops;
>   	vma->vm_private_data = bo;
>   	vma->vm_flags |= VM_MIXEDMAP;
>   	vma->vm_flags |= VM_IO | VM_DONTEXPAND;
> diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
> index cbf3180cb612..cfeaff5d9706 100644
> --- a/include/drm/ttm/ttm_bo_driver.h
> +++ b/include/drm/ttm/ttm_bo_driver.h
> @@ -443,6 +443,9 @@ extern struct ttm_bo_global {
>    * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
>    * @man: An array of mem_type_managers.
>    * @vma_manager: Address space manager
> + * @vm_ops: Pointer to the struct vm_operations_struct used for this
> + * device's VM operations. The driver may override this before the first
> + * mmap() call.
>    * lru_lock: Spinlock that protects the buffer+device lru lists and
>    * ddestroy lists.
>    * @dev_mapping: A pointer to the struct address_space representing the
> @@ -461,6 +464,7 @@ struct ttm_bo_device {
>   	struct ttm_bo_global *glob;
>   	struct ttm_bo_driver *driver;
>   	struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
> +	const struct vm_operations_struct *vm_ops;
>   
>   	/*
>   	 * Protected by internal locks.
> @@ -489,6 +493,8 @@ struct ttm_bo_device {
>   	bool no_retry;
>   };
>   
> +extern const struct vm_operations_struct ttm_bo_vm_ops;
> +
>   /**
>    * struct ttm_lru_bulk_move_pos
>    *