Re: [PATCH V1] accel/amdxdna: wait uninterruptibly for jobs in the HMM invalidate callback

[Mario Limonciello <mario.limonciello@amd.com>]

On 10/15/26 13:32, Lizhi Hou wrote:
> From: Matthew Brost <matthew.brost@intel.com>
> 
> aie2_hmm_invalidate() waits for the jobs using a BO before the CPU pages
> behind it are released, but does so interruptibly. When the task
> triggering the invalidation has a signal pending the wait returns
> -ERESTARTSYS immediately, the notifier completes and the pages can be
> freed or migrated while the device is still accessing them through the
> PASID.
> 
> An MMU notifier cannot fail a blockable invalidation, so wait
> uninterruptibly. With MAX_SCHEDULE_TIMEOUT an uninterruptible wait
> cannot time out either, so drop the now dead error handling.
> 
> Fixes: aac243092b70 ("accel/amdxdna: Add command execution")
> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by is not a valid tag.  It should be:

Assisted-by: LLM

> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
> ---
>   drivers/accel/amdxdna/aie2_ctx.c | 16 ++++++----------
>   1 file changed, 6 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/accel/amdxdna/aie2_ctx.c b/drivers/accel/amdxdna/aie2_ctx.c
> index 9c6b7353cbe9..84ab8a55b7ab 100644
> --- a/drivers/accel/amdxdna/aie2_ctx.c
> +++ b/drivers/accel/amdxdna/aie2_ctx.c
> @@ -1286,16 +1286,12 @@ int aie2_cmd_submit(struct amdxdna_hwctx *hwctx, struct amdxdna_sched_job *job,
>   void aie2_hmm_invalidate(struct amdxdna_gem_obj *abo,
>   			 unsigned long cur_seq)
>   {
> -	struct amdxdna_dev *xdna = to_xdna_dev(to_gobj(abo)->dev);
> -	struct drm_gem_object *gobj = to_gobj(abo);
> -	long ret;
> -
> -	ret = dma_resv_wait_timeout(gobj->resv, DMA_RESV_USAGE_BOOKKEEP,
> -				    true, MAX_SCHEDULE_TIMEOUT);
> -	if (!ret)
> -		XDNA_ERR(xdna, "Failed to wait for bo, ret %ld", ret);
> -	else if (ret == -ERESTARTSYS)
> -		XDNA_DBG(xdna, "Wait for bo interrupted by signal");
> +	/*
> +	 * The pages must not be released while the device may still access
> +	 * them, so this wait must be neither interruptible nor time limited.
> +	 */
> +	dma_resv_wait_timeout(to_gobj(abo)->resv, DMA_RESV_USAGE_BOOKKEEP,
> +			      false, MAX_SCHEDULE_TIMEOUT);
>   }
>   
>   int aie2_hwctx_heap_expand(struct amdxdna_hwctx *hwctx,