drm/xe/pf: Add function to sanitize VF resources

On current platforms it is a PF driver responsibility to clear
some of the VF's resources during a VF FLR. Add simple function
that will clear configured VF resources (GGTT, LMEM). We will
start using this function soon.
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240828210809.1528-2-michal.wajdeczko@intel.com

drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c

@@ -29,6 +29,7 @@
 #include "xe_guc_submit.h"
 #include "xe_lmtt.h"
 #include "xe_map.h"
+#include "xe_migrate.h"
 #include "xe_sriov.h"
 #include "xe_ttm_vram_mgr.h"
 #include "xe_wopcm.h"
@@ -1881,6 +1882,87 @@ int xe_gt_sriov_pf_config_release(struct xe_gt *gt, unsigned int vfid, bool forc
 	return force ? 0 : err;
 }
 
+static void pf_sanitize_ggtt(struct xe_ggtt_node *ggtt_region, unsigned int vfid)
+{
+	if (xe_ggtt_node_allocated(ggtt_region))
+		xe_ggtt_assign(ggtt_region, vfid);
+}
+
+static int pf_sanitize_lmem(struct xe_tile *tile, struct xe_bo *bo, long timeout)
+{
+	struct xe_migrate *m = tile->migrate;
+	struct dma_fence *fence;
+	int err;
+
+	if (!bo)
+		return 0;
+
+	xe_bo_lock(bo, false);
+	fence = xe_migrate_clear(m, bo, bo->ttm.resource, XE_MIGRATE_CLEAR_FLAG_FULL);
+	if (IS_ERR(fence)) {
+		err = PTR_ERR(fence);
+	} else if (!fence) {
+		err = -ENOMEM;
+	} else {
+		long ret = dma_fence_wait_timeout(fence, false, timeout);
+
+		err = ret > 0 ? 0 : ret < 0 ? ret : -ETIMEDOUT;
+		dma_fence_put(fence);
+		if (!err)
+			xe_gt_sriov_dbg_verbose(tile->primary_gt, "LMEM cleared in %dms\n",
+						jiffies_to_msecs(timeout - ret));
+	}
+	xe_bo_unlock(bo);
+
+	return err;
+}
+
+static int pf_sanitize_vf_resources(struct xe_gt *gt, u32 vfid, long timeout)
+{
+	struct xe_gt_sriov_config *config = pf_pick_vf_config(gt, vfid);
+	struct xe_tile *tile = gt_to_tile(gt);
+	struct xe_device *xe = gt_to_xe(gt);
+	int err = 0;
+
+	/*
+	 * Only GGTT and LMEM requires to be cleared by the PF.
+	 * GuC doorbell IDs and context IDs do not need any clearing.
+	 */
+	if (!xe_gt_is_media_type(gt)) {
+		pf_sanitize_ggtt(config->ggtt_region, vfid);
+		if (IS_DGFX(xe))
+			err = pf_sanitize_lmem(tile, config->lmem_obj, timeout);
+	}
+
+	return err;
+}
+
+/**
+ * xe_gt_sriov_pf_config_sanitize() - Sanitize VF's resources.
+ * @gt: the &xe_gt
+ * @vfid: the VF identifier (can't be PF)
+ * @timeout: maximum timeout to wait for completion in jiffies
+ *
+ * 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_sanitize(struct xe_gt *gt, unsigned int vfid, long timeout)
+{
+	int err;
+
+	xe_gt_assert(gt, vfid != PFID);
+
+	mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
+	err = pf_sanitize_vf_resources(gt, vfid, timeout);
+	mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
+
+	if (unlikely(err))
+		xe_gt_sriov_notice(gt, "VF%u resource sanitizing failed (%pe)\n",
+				   vfid, ERR_PTR(err));
+	return err;
+}
+
 /**
  * xe_gt_sriov_pf_config_push - Reprovision VF's configuration.
  * @gt: the &xe_gt

drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h

@@ -50,6 +50,7 @@ int xe_gt_sriov_pf_config_set_threshold(struct xe_gt *gt, unsigned int vfid,
 					enum xe_guc_klv_threshold_index index, u32 value);
 
 int xe_gt_sriov_pf_config_set_fair(struct xe_gt *gt, unsigned int vfid, unsigned int num_vfs);
+int xe_gt_sriov_pf_config_sanitize(struct xe_gt *gt, unsigned int vfid, long timeout);
 int xe_gt_sriov_pf_config_release(struct xe_gt *gt, unsigned int vfid, bool force);
 int xe_gt_sriov_pf_config_push(struct xe_gt *gt, unsigned int vfid, bool refresh);