Re: [PATCH v9 03/10] drm/xe/gt: Introduce FLR helpers

[Matthew Brost <matthew.brost@intel.com>]

On Wed, Jul 01, 2026 at 01:59:27PM +0530, Raag Jadav wrote:
> In preparation of usecases which require preparing/re-initializing GT and
> all its uCs before/after PCIe FLR, introduce flr_prepare/reinit() helpers.
> 
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> Tested-by: Lukasz Laguna <lukasz.laguna@intel.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
> v2: Add kernel doc (Matthew Brost)
> v4: Teardown exec queues instead of mangling scheduler pending list (Matthew Brost)
> v6: Add IS_DGFX() assert (Daniele)
>     s/flr_done/reinit (Daniele)
> ---
>  drivers/gpu/drm/xe/xe_gsc.c      | 14 +++++++
>  drivers/gpu/drm/xe/xe_gsc.h      |  1 +
>  drivers/gpu/drm/xe/xe_gt.c       | 23 ++++++++++
>  drivers/gpu/drm/xe/xe_gt.h       |  2 +
>  drivers/gpu/drm/xe/xe_guc.c      | 29 +++++++++++++
>  drivers/gpu/drm/xe/xe_guc.h      |  2 +
>  drivers/gpu/drm/xe/xe_huc.c      | 14 +++++++
>  drivers/gpu/drm/xe/xe_huc.h      |  1 +
>  drivers/gpu/drm/xe/xe_uc.c       | 72 ++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_uc.h       |  2 +
>  drivers/gpu/drm/xe/xe_uc_types.h | 14 +++++++
>  11 files changed, 174 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gsc.c b/drivers/gpu/drm/xe/xe_gsc.c
> index aab59dc647fb..7d5700624e46 100644
> --- a/drivers/gpu/drm/xe/xe_gsc.c
> +++ b/drivers/gpu/drm/xe/xe_gsc.c
> @@ -549,6 +549,20 @@ void xe_gsc_wait_for_worker_completion(struct xe_gsc *gsc)
>  		flush_work(&gsc->work);
>  }
>  
> +/**
> + * xe_gsc_reinit() - Re-initialize GSC after FLR
> + * @gsc: The GSC object
> + *
> + * Returns: 0 on success, negative error code otherwise.
> + */
> +int xe_gsc_reinit(struct xe_gsc *gsc)
> +{
> +	if (!xe_uc_fw_is_loadable(&gsc->fw))
> +		return 0;
> +
> +	return xe_uc_fw_reinit(&gsc->fw);
> +}
> +
>  void xe_gsc_stop_prepare(struct xe_gsc *gsc)
>  {
>  	struct xe_gt *gt = gsc_to_gt(gsc);
> diff --git a/drivers/gpu/drm/xe/xe_gsc.h b/drivers/gpu/drm/xe/xe_gsc.h
> index b8b8e0810ad9..ce390bffb163 100644
> --- a/drivers/gpu/drm/xe/xe_gsc.h
> +++ b/drivers/gpu/drm/xe/xe_gsc.h
> @@ -15,6 +15,7 @@ struct xe_hw_engine;
>  
>  int xe_gsc_init(struct xe_gsc *gsc);
>  int xe_gsc_init_post_hwconfig(struct xe_gsc *gsc);
> +int xe_gsc_reinit(struct xe_gsc *gsc);
>  void xe_gsc_wait_for_worker_completion(struct xe_gsc *gsc);
>  void xe_gsc_stop_prepare(struct xe_gsc *gsc);
>  void xe_gsc_load_start(struct xe_gsc *gsc);
> diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
> index 783eb6d631b5..acc28389b0d8 100644
> --- a/drivers/gpu/drm/xe/xe_gt.c
> +++ b/drivers/gpu/drm/xe/xe_gt.c
> @@ -908,6 +908,29 @@ static int do_gt_restart(struct xe_gt *gt)
>  	return 0;
>  }
>  
> +/**
> + * xe_gt_flr_prepare() - Prepare GT for FLR
> + * @gt: the GT object
> + *
> + * Prepare all GT uCs for FLR.
> + */
> +void xe_gt_flr_prepare(struct xe_gt *gt)
> +{
> +	xe_gt_sanitize(gt);
> +	xe_uc_flr_prepare(&gt->uc);
> +}
> +
> +/**
> + * xe_gt_reinit() - Re-initialize GT after FLR
> + * @gt: the GT object
> + *
> + * Returns: 0 on success, negative error code otherwise.
> + */
> +int xe_gt_reinit(struct xe_gt *gt)
> +{
> +	return xe_uc_reinit(&gt->uc);
> +}
> +
>  static void gt_reset_worker(struct work_struct *w)
>  {
>  	struct xe_gt *gt = container_of(w, typeof(*gt), reset.worker);
> diff --git a/drivers/gpu/drm/xe/xe_gt.h b/drivers/gpu/drm/xe/xe_gt.h
> index 4150aa594f05..488009b9b938 100644
> --- a/drivers/gpu/drm/xe/xe_gt.h
> +++ b/drivers/gpu/drm/xe/xe_gt.h
> @@ -45,8 +45,10 @@ static inline bool xe_fault_inject_gt_reset(void)
>  }
>  
>  struct xe_gt *xe_gt_alloc(struct xe_tile *tile);
> +void xe_gt_flr_prepare(struct xe_gt *gt);
>  int xe_gt_init_early(struct xe_gt *gt);
>  int xe_gt_init(struct xe_gt *gt);
> +int xe_gt_reinit(struct xe_gt *gt);
>  void xe_gt_mmio_init(struct xe_gt *gt);
>  void xe_gt_declare_wedged(struct xe_gt *gt);
>  int xe_gt_record_default_lrcs(struct xe_gt *gt);
> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> index 4023700ff2a9..0647c53a63d0 100644
> --- a/drivers/gpu/drm/xe/xe_guc.c
> +++ b/drivers/gpu/drm/xe/xe_guc.c
> @@ -1689,6 +1689,35 @@ void xe_guc_sanitize(struct xe_guc *guc)
>  	xe_guc_submit_disable(guc);
>  }
>  
> +/**
> + * xe_guc_flr_prepare() - Prepare GuC for FLR
> + * @guc: The GuC object
> + *
> + * Stop GuC submission and tear down exec queues.
> + */
> +void xe_guc_flr_prepare(struct xe_guc *guc)
> +{
> +	if (!xe_uc_fw_is_loadable(&guc->fw))
> +		return;
> +
> +	xe_guc_submit_stop(guc);
> +	xe_guc_submit_pause_abort(guc);
> +}
> +
> +/**
> + * xe_guc_reinit() - Re-initialize GuC after FLR
> + * @guc: The GuC object
> + *
> + * Returns: 0 on success, negative error code otherwise.
> + */
> +int xe_guc_reinit(struct xe_guc *guc)
> +{
> +	if (!xe_uc_fw_is_loadable(&guc->fw))
> +		return 0;
> +
> +	return xe_uc_fw_reinit(&guc->fw);
> +}
> +
>  int xe_guc_reset_prepare(struct xe_guc *guc)
>  {
>  	return xe_guc_submit_reset_prepare(guc);
> diff --git a/drivers/gpu/drm/xe/xe_guc.h b/drivers/gpu/drm/xe/xe_guc.h
> index 02514914f404..0eea9277439a 100644
> --- a/drivers/gpu/drm/xe/xe_guc.h
> +++ b/drivers/gpu/drm/xe/xe_guc.h
> @@ -32,10 +32,12 @@
>  struct drm_printer;
>  
>  void xe_guc_comm_init_early(struct xe_guc *guc);
> +void xe_guc_flr_prepare(struct xe_guc *guc);
>  int xe_guc_init_noalloc(struct xe_guc *guc);
>  int xe_guc_init(struct xe_guc *guc);
>  int xe_guc_init_post_hwconfig(struct xe_guc *guc);
>  int xe_guc_post_load_init(struct xe_guc *guc);
> +int xe_guc_reinit(struct xe_guc *guc);
>  int xe_guc_reset(struct xe_guc *guc);
>  int xe_guc_upload(struct xe_guc *guc);
>  int xe_guc_min_load_for_hwconfig(struct xe_guc *guc);
> diff --git a/drivers/gpu/drm/xe/xe_huc.c b/drivers/gpu/drm/xe/xe_huc.c
> index 57afe21444b1..c73e1acbd091 100644
> --- a/drivers/gpu/drm/xe/xe_huc.c
> +++ b/drivers/gpu/drm/xe/xe_huc.c
> @@ -296,6 +296,20 @@ void xe_huc_sanitize(struct xe_huc *huc)
>  	xe_uc_fw_sanitize(&huc->fw);
>  }
>  
> +/**
> + * xe_huc_reinit() - Re-initialize HuC after FLR
> + * @huc: The HuC object
> + *
> + * Returns: 0 on success, negative error code otherwise.
> + */
> +int xe_huc_reinit(struct xe_huc *huc)
> +{
> +	if (!xe_uc_fw_is_loadable(&huc->fw))
> +		return 0;
> +
> +	return xe_uc_fw_reinit(&huc->fw);
> +}
> +
>  void xe_huc_print_info(struct xe_huc *huc, struct drm_printer *p)
>  {
>  	struct xe_gt *gt = huc_to_gt(huc);
> diff --git a/drivers/gpu/drm/xe/xe_huc.h b/drivers/gpu/drm/xe/xe_huc.h
> index fa1c45e70443..cb1a770b4a9c 100644
> --- a/drivers/gpu/drm/xe/xe_huc.h
> +++ b/drivers/gpu/drm/xe/xe_huc.h
> @@ -19,6 +19,7 @@ enum xe_huc_auth_types {
>  
>  int xe_huc_init(struct xe_huc *huc);
>  int xe_huc_init_post_hwconfig(struct xe_huc *huc);
> +int xe_huc_reinit(struct xe_huc *huc);
>  int xe_huc_upload(struct xe_huc *huc);
>  int xe_huc_auth(struct xe_huc *huc, enum xe_huc_auth_types type);
>  bool xe_huc_is_authenticated(struct xe_huc *huc, enum xe_huc_auth_types type);
> diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
> index 75091bde0d50..a9b2442494ec 100644
> --- a/drivers/gpu/drm/xe/xe_uc.c
> +++ b/drivers/gpu/drm/xe/xe_uc.c
> @@ -15,6 +15,7 @@
>  #include "xe_guc_pc.h"
>  #include "xe_guc_rc.h"
>  #include "xe_guc_engine_activity.h"
> +#include "xe_guc_submit.h"
>  #include "xe_huc.h"
>  #include "xe_sriov.h"
>  #include "xe_wopcm.h"
> @@ -275,6 +276,77 @@ static void uc_reset_wait(struct xe_uc *uc)
>  		goto again;
>  }
>  
> +static void uc_flr_prepare(struct work_struct *w)
> +{
> +	struct xe_uc_flr *flr = container_of(w, struct xe_uc_flr, work);
> +	struct xe_uc *uc = flr->uc;
> +
> +	xe_assert(uc_to_xe(uc), xe_device_wedged(uc_to_xe(uc)));
> +
> +	xe_uc_reset_prepare(uc);
> +	xe_guc_flr_prepare(&uc->guc);
> +}
> +
> +static void uc_flr_sanitize(struct work_struct *w)
> +{
> +	struct xe_uc_flr *flr = container_of(w, struct xe_uc_flr, work);
> +	struct xe_uc *uc = flr->uc;
> +
> +	/* TODO: Sanitize GSC firmware */
> +	xe_assert(uc_to_xe(uc), IS_DGFX(uc_to_xe(uc)));
> +
> +	xe_uc_stop(uc);
> +	xe_uc_sanitize(uc);
> +}
> +
> +/**
> + * xe_uc_flr_prepare() - Prepare uCs for FLR
> + * @uc: The uC object
> + *
> + * Tear down pending work and stop all uCs.
> + */
> +void xe_uc_flr_prepare(struct xe_uc *uc)
> +{
> +	struct xe_uc_flr flr = { .uc = uc };
> +	struct xe_gt *gt = uc_to_gt(uc);
> +
> +	/*
> +	 * We'll be tearing down exec queues which signals all fences and frees the
> +	 * jobs but all of that happens asynchronously, so make sure we don't disrupt
> +	 * the scheduler while jobs are still in-flight.
> +	 */
> +	INIT_WORK_ONSTACK(&flr.work, uc_flr_prepare);
> +	queue_work(gt->ordered_wq, &flr.work);
> +	flush_work(&flr.work);
> +	destroy_work_on_stack(&flr.work);
> +
> +	INIT_WORK_ONSTACK(&flr.work, uc_flr_sanitize);
> +	queue_work(gt->ordered_wq, &flr.work);
> +	flush_work(&flr.work);
> +	destroy_work_on_stack(&flr.work);
> +}
> +
> +/**
> + * xe_uc_reinit() - Re-initialize uCs after FLR
> + * @uc: The uC object
> + *
> + * Returns: 0 on success, negative error code otherwise.
> + */
> +int xe_uc_reinit(struct xe_uc *uc)
> +{
> +	int ret;
> +
> +	ret = xe_guc_reinit(&uc->guc);
> +	if (ret)
> +		return ret;
> +
> +	ret = xe_huc_reinit(&uc->huc);
> +	if (ret)
> +		return ret;
> +
> +	return xe_gsc_reinit(&uc->gsc);
> +}
> +
>  void xe_uc_suspend_prepare(struct xe_uc *uc)
>  {
>  	xe_gsc_wait_for_worker_completion(&uc->gsc);
> diff --git a/drivers/gpu/drm/xe/xe_uc.h b/drivers/gpu/drm/xe/xe_uc.h
> index 255a54a8f876..e06f7937111f 100644
> --- a/drivers/gpu/drm/xe/xe_uc.h
> +++ b/drivers/gpu/drm/xe/xe_uc.h
> @@ -8,10 +8,12 @@
>  
>  struct xe_uc;
>  
> +void xe_uc_flr_prepare(struct xe_uc *uc);
>  int xe_uc_init_noalloc(struct xe_uc *uc);
>  int xe_uc_init(struct xe_uc *uc);
>  int xe_uc_init_post_hwconfig(struct xe_uc *uc);
>  int xe_uc_load_hw(struct xe_uc *uc);
> +int xe_uc_reinit(struct xe_uc *uc);
>  int xe_uc_reset_prepare(struct xe_uc *uc);
>  void xe_uc_runtime_resume(struct xe_uc *uc);
>  void xe_uc_runtime_suspend(struct xe_uc *uc);
> diff --git a/drivers/gpu/drm/xe/xe_uc_types.h b/drivers/gpu/drm/xe/xe_uc_types.h
> index 1708379dc834..2b47382f7b3b 100644
> --- a/drivers/gpu/drm/xe/xe_uc_types.h
> +++ b/drivers/gpu/drm/xe/xe_uc_types.h
> @@ -25,4 +25,18 @@ struct xe_uc {
>  	struct xe_wopcm wopcm;
>  };
>  
> +/**
> + * struct xe_uc_flr - uC FLR teardown
> + */
> +struct xe_uc_flr {
> +	/** @uc: uC to schedule FLR worker on */
> +	struct xe_uc *uc;
> +
> +	/**
> +	 * @work: worker for FLR teardown to be done async allowing to safely
> +	 * flush all code paths
> +	 */
> +	struct work_struct work;
> +};
> +
>  #endif
> -- 
> 2.43.0
>