drm/xe/pf: Add _locked variants of the VF PT config functions

In upcoming patches we will want to configure VF's preemption
timeout (PT) on all GTs under single lock to avoid potential
races due to parallel GT configuration attempts.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patch.msgid.link/20251030222348.186658-5-michal.wajdeczko@intel.com

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 f3e79a30d8ecef794f8b785e025d49536d0bd545..ce733bde43e3fffa3f20fea32eaf5e52b61dea6f 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
@@ -1835,47 +1835,78 @@ static int pf_get_preempt_timeout(struct xe_gt *gt, unsigned int vfid)
 }
 
 /**
- * xe_gt_sriov_pf_config_set_preempt_timeout - Configure preemption timeout for the VF.
+ * xe_gt_sriov_pf_config_set_preempt_timeout_locked() - Configure PF/VF preemption timeout.
  * @gt: the &xe_gt
- * @vfid: the VF identifier
+ * @vfid: the PF or VF identifier
  * @preempt_timeout: requested preemption timeout in microseconds (0 is infinity)
  *
- * This function can only be called on PF.
+ * This function can only be called on PF with the master mutex hold.
+ * It will log the provisioned value or an error in case of the failure.
  *
  * Return: 0 on success or a negative error code on failure.
  */
-int xe_gt_sriov_pf_config_set_preempt_timeout(struct xe_gt *gt, unsigned int vfid,
-                                             u32 preempt_timeout)
+int xe_gt_sriov_pf_config_set_preempt_timeout_locked(struct xe_gt *gt, unsigned int vfid,
+                                                    u32 preempt_timeout)
 {
        int err;
 
-       mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
+       lockdep_assert_held(xe_gt_sriov_pf_master_mutex(gt));
+
        err = pf_provision_preempt_timeout(gt, vfid, preempt_timeout);
-       mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
 
        return pf_config_set_u32_done(gt, vfid, preempt_timeout,
-                                     xe_gt_sriov_pf_config_get_preempt_timeout(gt, vfid),
+                                     pf_get_preempt_timeout(gt, vfid),
                                      "preemption timeout", preempt_timeout_unit, err);
 }
 
 /**
- * xe_gt_sriov_pf_config_get_preempt_timeout - Get VF's preemption timeout.
+ * xe_gt_sriov_pf_config_set_preempt_timeout() - Configure PF/VF preemption timeout.
  * @gt: the &xe_gt
- * @vfid: the VF identifier
+ * @vfid: the PF or VF identifier
+ * @preempt_timeout: requested preemption timeout in microseconds (0 is infinity)
  *
  * This function can only be called on PF.
  *
- * Return: VF's (or PF's) preemption timeout in microseconds.
+ * Return: 0 on success or a negative error code on failure.
  */
-u32 xe_gt_sriov_pf_config_get_preempt_timeout(struct xe_gt *gt, unsigned int vfid)
+int xe_gt_sriov_pf_config_set_preempt_timeout(struct xe_gt *gt, unsigned int vfid,
+                                             u32 preempt_timeout)
 {
-       u32 preempt_timeout;
+       guard(mutex)(xe_gt_sriov_pf_master_mutex(gt));
 
-       mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
-       preempt_timeout = pf_get_preempt_timeout(gt, vfid);
-       mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
+       return xe_gt_sriov_pf_config_set_preempt_timeout_locked(gt, vfid, preempt_timeout);
+}
+
+/**
+ * xe_gt_sriov_pf_config_get_preempt_timeout_locked() - Get PF/VF preemption timeout.
+ * @gt: the &xe_gt
+ * @vfid: the PF or VF identifier
+ *
+ * This function can only be called on PF with the master mutex hold.
+ *
+ * Return: preemption timeout in microseconds (or 0 if infinity).
+ */
+u32 xe_gt_sriov_pf_config_get_preempt_timeout_locked(struct xe_gt *gt, unsigned int vfid)
+{
+       lockdep_assert_held(xe_gt_sriov_pf_master_mutex(gt));
+
+       return pf_get_preempt_timeout(gt, vfid);
+}
+
+/**
+ * xe_gt_sriov_pf_config_get_preempt_timeout() - Get PF/VF preemption timeout.
+ * @gt: the &xe_gt
+ * @vfid: the PF or VF identifier
+ *
+ * This function can only be called on PF.
+ *
+ * Return: preemption timeout in microseconds (or 0 if infinity).
+ */
+u32 xe_gt_sriov_pf_config_get_preempt_timeout(struct xe_gt *gt, unsigned int vfid)
+{
+       guard(mutex)(xe_gt_sriov_pf_master_mutex(gt));
 
-       return preempt_timeout;
+       return pf_get_preempt_timeout(gt, vfid);
 }
 
 static const char *sched_priority_unit(u32 priority)

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 b4beb5a97031b2e70f1eca9ee4f4f266d4fd09c1..6bab5ad6c849f69707e23da7880e9a70fad0f243 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
@@ -48,6 +48,10 @@ u32 xe_gt_sriov_pf_config_get_preempt_timeout(struct xe_gt *gt, unsigned int vfi
 int xe_gt_sriov_pf_config_set_preempt_timeout(struct xe_gt *gt, unsigned int vfid,
                                              u32 preempt_timeout);
 
+u32 xe_gt_sriov_pf_config_get_preempt_timeout_locked(struct xe_gt *gt, unsigned int vfid);
+int xe_gt_sriov_pf_config_set_preempt_timeout_locked(struct xe_gt *gt, unsigned int vfid,
+                                                    u32 preempt_timeout);
+
 u32 xe_gt_sriov_pf_config_get_sched_priority(struct xe_gt *gt, unsigned int vfid);
 int xe_gt_sriov_pf_config_set_sched_priority(struct xe_gt *gt, unsigned int vfid, u32 priority);