drm/xe/oa: Assign hwe for OAM_SAG

Because OAM_SAG doesn't have an attached hwe, assign another hwe belonging
to the same gt (and different OAM unit) to OAM_SAG. A hwe is needed for
batch submissions to program OA HW.

v2: Assign an engine with a valid OA unit for OAM_SAG (Umesh)

Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://lore.kernel.org/r/20250606192618.4133817-5-ashutosh.dixit@intel.com

diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c
index 19529c861523b2eae205ce3c5ac5968b085dab4c..f41dac107e4a3b8151cf01c91e78129fe4cd3697 100644 (file)
--- a/drivers/gpu/drm/xe/xe_oa.c
+++ b/drivers/gpu/drm/xe/xe_oa.c
@@ -1923,37 +1923,48 @@ u16 xe_oa_unit_id(struct xe_hw_engine *hwe)
                hwe->oa_unit->oa_unit_id : U16_MAX;
 }
 
+/* A hwe must be assigned to stream/oa_unit for batch submissions */
 static int xe_oa_assign_hwe(struct xe_oa *oa, struct xe_oa_open_param *param)
 {
-       struct xe_gt *gt;
-       int i, ret = 0;
+       struct xe_hw_engine *hwe;
+       enum xe_hw_engine_id id;
+       int ret = 0;
+
+       /* If not provided, OA unit defaults to OA unit 0 as per uapi */
+       if (!param->oa_unit)
+               param->oa_unit = &xe_device_get_gt(oa->xe, 0)->oa.oa_unit[0];
 
+       /* When we have an exec_q, get hwe from the exec_q */
        if (param->exec_q) {
-               /* When we have an exec_q, get hwe from the exec_q */
                param->hwe = xe_gt_hw_engine(param->exec_q->gt, param->exec_q->class,
                                             param->engine_instance, true);
-       } else {
-               struct xe_hw_engine *hwe;
-               enum xe_hw_engine_id id;
-
-               /* Else just get the first hwe attached to the oa unit */
-               for_each_gt(gt, oa->xe, i) {
-                       for_each_hw_engine(hwe, gt, id) {
-                               if (hwe->oa_unit == param->oa_unit) {
-                                       param->hwe = hwe;
-                                       goto out;
-                               }
-                       }
-               }
+               if (!param->hwe || param->hwe->oa_unit != param->oa_unit)
+                       goto err;
+               goto out;
        }
-out:
-       if (!param->hwe || param->hwe->oa_unit != param->oa_unit) {
-               drm_dbg(&oa->xe->drm, "Unable to find hwe (%d, %d) for OA unit ID %d\n",
-                       param->exec_q ? param->exec_q->class : -1,
-                       param->engine_instance, param->oa_unit->oa_unit_id);
-               ret = -EINVAL;
+
+       /* Else just get the first hwe attached to the oa unit */
+       for_each_hw_engine(hwe, param->oa_unit->gt, id) {
+               if (hwe->oa_unit == param->oa_unit) {
+                       param->hwe = hwe;
+                       goto out;
+               }
        }
 
+       /* If we still didn't find a hwe, just get one with a valid oa_unit from the same gt */
+       for_each_hw_engine(hwe, param->oa_unit->gt, id) {
+               if (!hwe->oa_unit)
+                       continue;
+
+               param->hwe = hwe;
+               goto out;
+       }
+err:
+       drm_dbg(&oa->xe->drm, "Unable to find hwe (%d, %d) for OA unit ID %d\n",
+               param->exec_q ? param->exec_q->class : -1,
+               param->engine_instance, param->oa_unit->oa_unit_id);
+       ret = -EINVAL;
+out:
        return ret;
 }
 
@@ -2578,6 +2589,8 @@ static void __xe_oa_init_oa_units(struct xe_gt *gt)
                                DRM_XE_OA_UNIT_TYPE_OAM_SAG : DRM_XE_OA_UNIT_TYPE_OAM;
                }
 
+               u->gt = gt;
+
                xe_mmio_write32(&gt->mmio, u->regs.oa_ctrl, 0);
 
                /* Ensure MMIO trigger remains disabled till there is a stream */

diff --git a/drivers/gpu/drm/xe/xe_oa_types.h b/drivers/gpu/drm/xe/xe_oa_types.h
index a01c85931e2a51d0a37a9baa9df6f484b377ebae..2628f78c4e8dc46d282d1de6aeef72fc3b44da53 100644 (file)
--- a/drivers/gpu/drm/xe/xe_oa_types.h
+++ b/drivers/gpu/drm/xe/xe_oa_types.h
@@ -95,6 +95,9 @@ struct xe_oa_unit {
        /** @oa_unit_id: identifier for the OA unit */
        u16 oa_unit_id;
 
+       /** @gt: gt associated with the OA unit */
+       struct xe_gt *gt;
+
        /** @type: Type of OA unit - OAM, OAG etc. */
        enum drm_xe_oa_unit_type type;