[PATCH v5 2/2] drm/xe: remove GuC reload in D3Hot path

Matthew Brost matthew.brost at intel.com
Thu Aug 1 21:02:13 UTC 2024


On Thu, Aug 01, 2024 at 10:55:07PM +0200, Michal Wajdeczko wrote:
> 
> 
> On 01.08.2024 22:42, Matthew Brost wrote:
> > On Thu, Aug 01, 2024 at 11:29:41AM +0530, Riana Tauro wrote:
> >> Currently GuC is reloaded for both runtime resume and system resume.
> >> For D3hot <-> D0 transitions no power is lost during suspend so GuC reload
> >> is not necessary.
> >>
> >> Remove GuC reload from D3Hot path and only enable/disable CTB
> >> communication.
> >>
> >> v2: rebase
> >>
> >> v3: fix commit message
> >>     add kernel-doc for gt suspend and resume methods
> >>     fix comment
> >>     do not split register and enable calls of CT (Michal)
> >>
> >> v4: fix commit message
> >>     fix comment (Karthik)
> >>     split patches
> >>     correct kernel-doc (Rodrigo)
> >>
> >> v5: do not expose internal function of CT layer (Michal)
> >>     remove wait for outstanding g2h as it will be always zero,
> >>     use assert instead (Matthew Brost)
> >>     use runtime suspend and runtime resume pair for CT layer
> >>     (Michal / Matthew Brost)
> >>
> >> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
> >> ---
> >>  drivers/gpu/drm/xe/xe_gt.c     | 33 +++++++++++++++++++++++++++++----
> >>  drivers/gpu/drm/xe/xe_gt.h     |  4 ++--
> >>  drivers/gpu/drm/xe/xe_guc.c    | 30 ++++++++++++++++++++++++++++++
> >>  drivers/gpu/drm/xe/xe_guc.h    |  2 ++
> >>  drivers/gpu/drm/xe/xe_guc_ct.c | 31 +++++++++++++++++++++++++++++++
> >>  drivers/gpu/drm/xe/xe_guc_ct.h |  3 +++
> >>  drivers/gpu/drm/xe/xe_pm.c     |  8 ++++----
> >>  drivers/gpu/drm/xe/xe_uc.c     | 28 ++++++++++++++++++++++++++++
> >>  drivers/gpu/drm/xe/xe_uc.h     |  2 ++
> >>  9 files changed, 131 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
> >> index 58895ed22f6e..e0b13dc7663b 100644
> >> --- a/drivers/gpu/drm/xe/xe_gt.c
> >> +++ b/drivers/gpu/drm/xe/xe_gt.c
> >> @@ -831,8 +831,16 @@ void xe_gt_suspend_prepare(struct xe_gt *gt)
> >>  	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FORCEWAKE_ALL));
> >>  }
> >>  
> >> -int xe_gt_suspend(struct xe_gt *gt)
> >> +/**
> >> + * xe_gt_suspend - GT suspend helper
> >> + * @gt: GT object
> >> + * @runtime: true if this is from runtime suspend
> >> + *
> >> + * Return: 0 on success, negative error code otherwise.
> >> + */
> >> +int xe_gt_suspend(struct xe_gt *gt, bool runtime)
> >>  {
> >> +	struct xe_device *xe = gt_to_xe(gt);
> >>  	int err;
> >>  
> >>  	xe_gt_dbg(gt, "suspending\n");
> >> @@ -842,7 +850,11 @@ int xe_gt_suspend(struct xe_gt *gt)
> >>  	if (err)
> >>  		goto err_msg;
> >>  
> >> -	err = xe_uc_suspend(&gt->uc);
> >> +	if (runtime && !xe->d3cold.allowed)
> >> +		err = xe_uc_runtime_suspend(&gt->uc);
> >> +	else
> >> +		err = xe_uc_suspend(&gt->uc);
> >> +
> >>  	if (err)
> >>  		goto err_force_wake;
> >>  
> >> @@ -881,8 +893,16 @@ int xe_gt_sanitize_freq(struct xe_gt *gt)
> >>  	return ret;
> >>  }
> >>  
> >> -int xe_gt_resume(struct xe_gt *gt)
> >> +/**
> >> + * xe_gt_resume - GT resume helper
> >> + * @gt: GT object
> >> + * @runtime: true if called on runtime resume
> >> + *
> >> + * Return: 0 on success, negative error code otherwise.
> >> + */
> >> +int xe_gt_resume(struct xe_gt *gt, bool runtime)
> >>  {
> >> +	struct xe_device *xe = gt_to_xe(gt);
> >>  	int err;
> >>  
> >>  	xe_gt_dbg(gt, "resuming\n");
> >> @@ -890,7 +910,12 @@ int xe_gt_resume(struct xe_gt *gt)
> >>  	if (err)
> >>  		goto err_msg;
> >>  
> >> -	err = do_gt_restart(gt);
> >> +	/* GuC is still alive at D3hot, no need to reload it */
> >> +	if (runtime && !xe->d3cold.allowed)
> >> +		xe_uc_runtime_resume(&gt->uc);
> >> +	else
> >> +		err = do_gt_restart(gt);
> >> +
> >>  	if (err)
> >>  		goto err_force_wake;
> >>  
> >> diff --git a/drivers/gpu/drm/xe/xe_gt.h b/drivers/gpu/drm/xe/xe_gt.h
> >> index 8b1a5027dcf2..21f27ca23b67 100644
> >> --- a/drivers/gpu/drm/xe/xe_gt.h
> >> +++ b/drivers/gpu/drm/xe/xe_gt.h
> >> @@ -53,8 +53,8 @@ int xe_gt_record_default_lrcs(struct xe_gt *gt);
> >>  void xe_gt_record_user_engines(struct xe_gt *gt);
> >>  
> >>  void xe_gt_suspend_prepare(struct xe_gt *gt);
> >> -int xe_gt_suspend(struct xe_gt *gt);
> >> -int xe_gt_resume(struct xe_gt *gt);
> >> +int xe_gt_suspend(struct xe_gt *gt, bool runtime);
> >> +int xe_gt_resume(struct xe_gt *gt, bool runtime);
> >>  void xe_gt_reset_async(struct xe_gt *gt);
> >>  void xe_gt_sanitize(struct xe_gt *gt);
> >>  int xe_gt_sanitize_freq(struct xe_gt *gt);
> >> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> >> index 1ff49318f001..e1923a00a9f6 100644
> >> --- a/drivers/gpu/drm/xe/xe_guc.c
> >> +++ b/drivers/gpu/drm/xe/xe_guc.c
> >> @@ -881,6 +881,8 @@ int xe_guc_enable_communication(struct xe_guc *guc, bool register_ctb)
> >>  
> >>  	if (register_ctb)
> >>  		err = xe_guc_ct_enable(&guc->ct);
> >> +	else
> >> +		xe_guc_ct_runtime_resume(&guc->ct);
> >>  
> >>  	if (err)
> >>  		return err;
> >> @@ -1112,6 +1114,34 @@ void xe_guc_sanitize(struct xe_guc *guc)
> >>  	guc->submission_state.enabled = false;
> >>  }
> >>  
> >> +/**
> >> + * xe_guc_runtime_suspend - GuC runtime suspend
> >> + * @guc: GuC object
> >> + *
> >> + * Return: 0 on success, negative error code otherwise.
> >> + */
> >> +int xe_guc_runtime_suspend(struct xe_guc *guc)
> >> +{
> >> +	return xe_guc_ct_runtime_suspend(&guc->ct);
> >> +}
> >> +
> >> +/**
> >> + * xe_guc_runtime_resume - GuC runtime resume
> >> + * @guc: GuC object
> >> + *
> >> + * This function enables GuC CTB communication
> >> + */
> >> +void xe_guc_runtime_resume(struct xe_guc *guc)
> >> +{
> >> +	/*
> >> +	 * Power is not lost when in D3Hot state,
> >> +	 * hence it is not necessary to reload GuC
> >> +	 * everytime. Only enable interrupts and
> >> +	 * CTB communication during resume
> >> +	 */
> >> +	xe_guc_enable_communication(guc, false);
> >> +}
> >> +
> >>  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 13e75573f7d0..ddc87798e176 100644
> >> --- a/drivers/gpu/drm/xe/xe_guc.h
> >> +++ b/drivers/gpu/drm/xe/xe_guc.h
> >> @@ -22,6 +22,8 @@ int xe_guc_upload(struct xe_guc *guc);
> >>  int xe_guc_min_load_for_hwconfig(struct xe_guc *guc);
> >>  int xe_guc_enable_communication(struct xe_guc *guc, bool register_ctb);
> >>  int xe_guc_suspend(struct xe_guc *guc);
> >> +int xe_guc_runtime_suspend(struct xe_guc *guc);
> >> +void xe_guc_runtime_resume(struct xe_guc *guc);
> >>  void xe_guc_notify(struct xe_guc *guc);
> >>  int xe_guc_auth_huc(struct xe_guc *guc, u32 rsa_addr);
> >>  int xe_guc_mmio_send(struct xe_guc *guc, const u32 *request, u32 len);
> >> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
> >> index beeeb120d1fc..9e42c5d29971 100644
> >> --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> >> +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> >> @@ -419,6 +419,37 @@ int xe_guc_ct_enable(struct xe_guc_ct *ct)
> >>  	return err;
> >>  }
> >>  
> >> +/**
> >> + * xe_guc_ct_runtime_resume- GuC CT runtime resume
> >> + * @ct: the &xe_guc_ct
> >> + *
> >> + * Mark GuC CT as enabled on runtime resume
> >> + */
> >> +void xe_guc_ct_runtime_resume(struct xe_guc_ct *ct)
> >> +{
> > 
> > I'd assert here g2h head and tail are equal in memory to ensure we know
> > we are doing with the PM as we shouldn't have any g2h on runtime resume
> > if we have the PM correct. If they are unequal, this isn't fatal just
> > kick the g2h handler.
> >


Based on Michals feedback below, I guess we xe_gt_WARN_ON here too for
g2h head / tail check + fallback to kick the g2h handler.

> >> +	xe_guc_ct_set_state(ct, XE_GUC_CT_STATE_ENABLED);
> >> +}
> >> +
> >> +/**
> >> + * xe_guc_ct_runtime_suspend- GuC CT runtime suspend
> >> + * @ct: the &xe_guc_ct
> >> + *
> >> + * Mark GuC CT as disabled on runtime suspend
> >> + *
> >> + * Return: 0 on success, negative error code otherwise
> >> + */
> >> +int xe_guc_ct_runtime_suspend(struct xe_guc_ct *ct)
> >> +{
> > 
> > Nit, I'd write it like this:
> > 
> > xe_gt_assert(ct_to_gt(ct), !ct->g2h_outstanding);
> > if (ct->g2h_outstanding)
> > 	return -EBUSY;
> 
> IMO neither option is good as xe_assert() is not to be used where you
> plan to use fallback path [1] you may want to use xe_gt_WARN_ON instead
> 

So like:

if (xe_gt_WARN_ON(ct_to_gt(ct), ct->g2h_outstanding))
	return -EBUSY;

Yea, that is probably better.

Matt

> Michal
> 
> [1] https://docs.kernel.org/gpu/xe/xe_debugging.html
> 
> > 
> > Matt
> > 
> >> +	if (ct->g2h_outstanding) {
> >> +		xe_gt_assert(ct_to_gt(ct), !ct->g2h_outstanding);
> >> +		return -EBUSY;
> >> +	}
> >> +
> >> +	xe_guc_ct_disable(ct);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >>  static void stop_g2h_handler(struct xe_guc_ct *ct)
> >>  {
> >>  	cancel_work_sync(&ct->g2h_worker);
> >> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.h b/drivers/gpu/drm/xe/xe_guc_ct.h
> >> index 190202fce2d0..0cf9d77feb35 100644
> >> --- a/drivers/gpu/drm/xe/xe_guc_ct.h
> >> +++ b/drivers/gpu/drm/xe/xe_guc_ct.h
> >> @@ -16,6 +16,9 @@ void xe_guc_ct_disable(struct xe_guc_ct *ct);
> >>  void xe_guc_ct_stop(struct xe_guc_ct *ct);
> >>  void xe_guc_ct_fast_path(struct xe_guc_ct *ct);
> >>  
> >> +void xe_guc_ct_runtime_resume(struct xe_guc_ct *ct);
> >> +int xe_guc_ct_runtime_suspend(struct xe_guc_ct *ct);
> >> +
> >>  struct xe_guc_ct_snapshot *
> >>  xe_guc_ct_snapshot_capture(struct xe_guc_ct *ct, bool atomic);
> >>  void xe_guc_ct_snapshot_print(struct xe_guc_ct_snapshot *snapshot,
> >> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> >> index 9f3c14fd9f33..c73a728a7450 100644
> >> --- a/drivers/gpu/drm/xe/xe_pm.c
> >> +++ b/drivers/gpu/drm/xe/xe_pm.c
> >> @@ -101,7 +101,7 @@ int xe_pm_suspend(struct xe_device *xe)
> >>  	xe_display_pm_suspend(xe, false);
> >>  
> >>  	for_each_gt(gt, xe, id) {
> >> -		err = xe_gt_suspend(gt);
> >> +		err = xe_gt_suspend(gt, false);
> >>  		if (err) {
> >>  			xe_display_pm_resume(xe, false);
> >>  			goto err;
> >> @@ -157,7 +157,7 @@ int xe_pm_resume(struct xe_device *xe)
> >>  	xe_display_pm_resume(xe, false);
> >>  
> >>  	for_each_gt(gt, xe, id)
> >> -		xe_gt_resume(gt);
> >> +		xe_gt_resume(gt, false);
> >>  
> >>  	err = xe_bo_restore_user(xe);
> >>  	if (err)
> >> @@ -374,7 +374,7 @@ int xe_pm_runtime_suspend(struct xe_device *xe)
> >>  	}
> >>  
> >>  	for_each_gt(gt, xe, id) {
> >> -		err = xe_gt_suspend(gt);
> >> +		err = xe_gt_suspend(gt, true);
> >>  		if (err)
> >>  			goto out;
> >>  	}
> >> @@ -428,7 +428,7 @@ int xe_pm_runtime_resume(struct xe_device *xe)
> >>  	xe_irq_resume(xe);
> >>  
> >>  	for_each_gt(gt, xe, id)
> >> -		xe_gt_resume(gt);
> >> +		xe_gt_resume(gt, true);
> >>  
> >>  	if (xe->d3cold.allowed) {
> >>  		xe_display_pm_resume(xe, true);
> >> diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
> >> index fa98e9f22631..8e535153cc62 100644
> >> --- a/drivers/gpu/drm/xe/xe_uc.c
> >> +++ b/drivers/gpu/drm/xe/xe_uc.c
> >> @@ -288,6 +288,34 @@ int xe_uc_suspend(struct xe_uc *uc)
> >>  	return xe_guc_suspend(&uc->guc);
> >>  }
> >>  
> >> +/**
> >> + * xe_uc_runtime_suspend - uC runtime suspend
> >> + * @uc: uC object
> >> + *
> >> + * Return: 0 on success, negative error code otherwise
> >> + */
> >> +int xe_uc_runtime_suspend(struct xe_uc *uc)
> >> +{
> >> +	if (!xe_device_uc_enabled(uc_to_xe(uc)))
> >> +		return 0;
> >> +
> >> +	return xe_guc_runtime_suspend(&uc->guc);
> >> +}
> >> +
> >> +/**
> >> + * xe_uc_runtime_resume - uC runtime resume
> >> + * @uc: uC object
> >> + *
> >> + * Called while resuming from D3Hot
> >> + */
> >> +void xe_uc_runtime_resume(struct xe_uc *uc)
> >> +{
> >> +	if (!xe_device_uc_enabled(uc_to_xe(uc)))
> >> +		return;
> >> +
> >> +	xe_guc_runtime_resume(&uc->guc);
> >> +}
> >> +
> >>  /**
> >>   * xe_uc_remove() - Clean up the UC structures before driver removal
> >>   * @uc: the UC object
> >> diff --git a/drivers/gpu/drm/xe/xe_uc.h b/drivers/gpu/drm/xe/xe_uc.h
> >> index 506517c11333..1e223d67086a 100644
> >> --- a/drivers/gpu/drm/xe/xe_uc.h
> >> +++ b/drivers/gpu/drm/xe/xe_uc.h
> >> @@ -15,6 +15,8 @@ int xe_uc_init_hw(struct xe_uc *uc);
> >>  int xe_uc_fini_hw(struct xe_uc *uc);
> >>  void xe_uc_gucrc_disable(struct xe_uc *uc);
> >>  int xe_uc_reset_prepare(struct xe_uc *uc);
> >> +int xe_uc_runtime_suspend(struct xe_uc *uc);
> >> +void xe_uc_runtime_resume(struct xe_uc *uc);
> >>  void xe_uc_stop_prepare(struct xe_uc *uc);
> >>  void xe_uc_stop(struct xe_uc *uc);
> >>  int xe_uc_start(struct xe_uc *uc);
> >> -- 
> >> 2.40.0
> >>


More information about the Intel-xe mailing list