Re: [PATCH 2/3] drm/xe/pf: Add _locked variant of the contexts bulk config function

Michal Wajdeczko <[email protected]> wrote on śro [2026-sie-05 17:47:32 +0200]:
> We will soon want to provision all VFs, including their GuC context
> IDs config, in one step. Split existing GuC IDs bulk configuration
> function into two functions, one of which will expect the master
> lock to be already taken. Use this new function in the fair GuC IDs
> provisioning.
> 
> Signed-off-by: Michal Wajdeczko <[email protected]>
> ---
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c | 37 ++++++++++++++++------
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h |  2 ++
>  2 files changed, 29 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> index 47623315d615..4976d8c018ce 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> @@ -1116,7 +1116,7 @@ static int pf_config_bulk_set_u32_done(struct xe_gt *gt, unsigned int first, uns
>  }
>  
>  /**
> - * xe_gt_sriov_pf_config_bulk_set_ctxs - Provision many VFs with GuC context IDs.
> + * xe_gt_sriov_pf_config_bulk_set_ctxs_locked() - Provision many VFs with GuC context IDs.
>   * @gt: the &xe_gt
>   * @vfid: starting VF identifier
>   * @num_vfs: number of VFs to provision
> @@ -1126,30 +1126,48 @@ static int pf_config_bulk_set_u32_done(struct xe_gt *gt, unsigned int first, uns
>   *
>   * Return: 0 on success or a negative error code on failure.
>   */
> -int xe_gt_sriov_pf_config_bulk_set_ctxs(struct xe_gt *gt, unsigned int vfid,
> -					unsigned int num_vfs, u32 num_ctxs)
> +int xe_gt_sriov_pf_config_bulk_set_ctxs_locked(struct xe_gt *gt, unsigned int vfid,
> +					       unsigned int num_vfs, u32 num_ctxs)
>  {
>  	unsigned int n;
>  	int err = 0;
>  
>  	xe_gt_assert(gt, vfid);
> +	lockdep_assert_held(xe_gt_sriov_pf_master_mutex(gt));
>  
>  	if (!num_vfs)
>  		return 0;
>  
> -	mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
>  	for (n = vfid; n < vfid + num_vfs; n++) {
>  		err = pf_provision_vf_ctxs(gt, n, num_ctxs);
>  		if (err)
>  			break;
>  	}
> -	mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
>  
>  	return pf_config_bulk_set_u32_done(gt, vfid, num_vfs, num_ctxs,
> -					   xe_gt_sriov_pf_config_get_ctxs,
> +					   pf_get_vf_config_ctxs,
>  					   "GuC context IDs", no_unit, n, err);
>  }
>  
> +/**
> + * xe_gt_sriov_pf_config_bulk_set_ctxs() - Provision many VFs with GuC context IDs.
> + * @gt: the &xe_gt
> + * @vfid: starting VF identifier
> + * @num_vfs: number of VFs to provision
> + * @num_ctxs: requested number of GuC contexts IDs (0 to release)
> + *
> + * This function can only be called on PF.
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int xe_gt_sriov_pf_config_bulk_set_ctxs(struct xe_gt *gt, unsigned int vfid,
> +					unsigned int num_vfs, u32 num_ctxs)
> +{
> +	guard(mutex)(xe_gt_sriov_pf_master_mutex(gt));
> +
> +	return xe_gt_sriov_pf_config_bulk_set_ctxs_locked(gt, vfid, num_vfs, num_ctxs);
> +}
> +
>  static u32 pf_profile_fair_ctxs(struct xe_gt *gt, unsigned int num_vfs)
>  {
>  	bool admin_only_pf = xe_sriov_pf_admin_only(gt_to_xe(gt));
> @@ -1198,10 +1216,9 @@ int xe_gt_sriov_pf_config_set_fair_ctxs(struct xe_gt *gt, unsigned int vfid,
>  	xe_gt_assert(gt, vfid);
>  	xe_gt_assert(gt, num_vfs);
>  
> -	mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
> +	guard(mutex)(xe_gt_sriov_pf_master_mutex(gt));
> +
>  	fair = pf_estimate_fair_ctxs(gt, num_vfs);
> -	mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
> -
>  	if (!fair)
>  		return -ENOSPC;
>  
> @@ -1210,7 +1227,7 @@ int xe_gt_sriov_pf_config_set_fair_ctxs(struct xe_gt *gt, unsigned int vfid,
>  		xe_gt_sriov_info(gt, "Using non-profile provisioning (%s %u vs %u)\n",
>  				 "GuC context IDs", fair, profile);
>  
> -	return xe_gt_sriov_pf_config_bulk_set_ctxs(gt, vfid, num_vfs, fair);
> +	return xe_gt_sriov_pf_config_bulk_set_ctxs_locked(gt, vfid, num_vfs, fair);
>  }
>  
>  static u32 pf_get_min_spare_dbs(struct xe_gt *gt)
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
> index 3741202908ee..a14ca7bf7e4d 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
> @@ -26,6 +26,8 @@ int xe_gt_sriov_pf_config_set_ctxs(struct xe_gt *gt, unsigned int vfid, u32 num_
>  int xe_gt_sriov_pf_config_set_fair_ctxs(struct xe_gt *gt, unsigned int vfid, unsigned int num_vfs);
>  int xe_gt_sriov_pf_config_bulk_set_ctxs(struct xe_gt *gt, unsigned int vfid, unsigned int num_vfs,
>  					u32 num_ctxs);
> +int xe_gt_sriov_pf_config_bulk_set_ctxs_locked(struct xe_gt *gt, unsigned int vfid,
> +					       unsigned int num_vfs, u32 num_ctxs);
>  
>  u32 xe_gt_sriov_pf_config_get_dbs(struct xe_gt *gt, unsigned int vfid);
>  int xe_gt_sriov_pf_config_set_dbs(struct xe_gt *gt, unsigned int vfid, u32 num_dbs);
> -- 
> 2.47.1
> 


Reviewed-by: Piotr Piórkowski <[email protected]>


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