[PATCH v2] drm/xe/pf: Skip LMTT update if no LMEM was provisioned

[Michal Wajdeczko]

During VF unprovisioning, if VF was not provisioned with LMEM,
there is no need to trigger LMTT update, as VF LMTT was never
set. This will spare us sending full TLB invalidation requests.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski at intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
---
v2: don't use local var (Jonathan) add comment (Michal)
---
 drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 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 f00cce81f1ff..c8f0320d032f 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
@@ -1434,7 +1434,8 @@ static int pf_update_vf_lmtt(struct xe_device *xe, unsigned int vfid)
 	return err;
 }
 
-static void pf_release_vf_config_lmem(struct xe_gt *gt, struct xe_gt_sriov_config *config)
+/* Return: %true if there was an LMEM provisioned, %false otherwise */
+static bool pf_release_vf_config_lmem(struct xe_gt *gt, struct xe_gt_sriov_config *config)
 {
 	xe_gt_assert(gt, IS_DGFX(gt_to_xe(gt)));
 	xe_gt_assert(gt, xe_gt_is_main_type(gt));
@@ -1443,7 +1444,9 @@ static void pf_release_vf_config_lmem(struct xe_gt *gt, struct xe_gt_sriov_confi
 	if (config->lmem_obj) {
 		xe_bo_unpin_map_no_vm(config->lmem_obj);
 		config->lmem_obj = NULL;
+		return true;
 	}
+	return false;
 }
 
 static int pf_provision_vf_lmem(struct xe_gt *gt, unsigned int vfid, u64 size)
@@ -2021,12 +2024,13 @@ static void pf_release_vf_config(struct xe_gt *gt, unsigned int vfid)
 {
 	struct xe_gt_sriov_config *config = pf_pick_vf_config(gt, vfid);
 	struct xe_device *xe = gt_to_xe(gt);
+	bool released;
 
 	if (xe_gt_is_main_type(gt)) {
 		pf_release_vf_config_ggtt(gt, config);
 		if (IS_DGFX(xe)) {
-			pf_release_vf_config_lmem(gt, config);
-			if (xe_device_has_lmtt(xe))
+			released = pf_release_vf_config_lmem(gt, config);
+			if (released && xe_device_has_lmtt(xe))
 				pf_update_vf_lmtt(xe, vfid);
 		}
 	}
-- 
2.47.1