[PATCH 2/3] drm/xe/vf: Return error code from xe_hw_engine_read_timestamp()

[Marcin Bernatowicz]

Modify xe_hw_engine_read_timestamp() to return an error code instead
of a u64 timestamp. Return -EOPNOTSUPP when called from Virtual Function
(VF) mode to avoid reading the inaccessible RING_TIMESTAMP register.

Update function signature to pass the timestamp via a pointer argument.

Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz at linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Michał Winiarski <michal.winiarski at intel.com>
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
---
 drivers/gpu/drm/xe/xe_hw_engine.c | 10 ++++++++--
 drivers/gpu/drm/xe/xe_hw_engine.h |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
index fc447751fe78..ab91c15f3a8b 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine.c
+++ b/drivers/gpu/drm/xe/xe_hw_engine.c
@@ -981,9 +981,15 @@ const char *xe_hw_engine_class_to_str(enum xe_engine_class class)
 	return NULL;
 }
 
-u64 xe_hw_engine_read_timestamp(struct xe_hw_engine *hwe)
+int xe_hw_engine_read_timestamp(struct xe_hw_engine *hwe, u64 *gpu_timestamp)
 {
-	return xe_mmio_read64_2x32(&hwe->gt->mmio, RING_TIMESTAMP(hwe->mmio_base));
+	if (IS_SRIOV_VF(gt_to_xe(hwe->gt)))
+		return -EOPNOTSUPP;
+
+	*gpu_timestamp = xe_mmio_read64_2x32(&hwe->gt->mmio,
+					     RING_TIMESTAMP(hwe->mmio_base));
+
+	return 0;
 }
 
 enum xe_force_wake_domains xe_hw_engine_to_fw_domain(struct xe_hw_engine *hwe)
diff --git a/drivers/gpu/drm/xe/xe_hw_engine.h b/drivers/gpu/drm/xe/xe_hw_engine.h
index 6b5f9fa2a594..df377da82770 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine.h
+++ b/drivers/gpu/drm/xe/xe_hw_engine.h
@@ -73,7 +73,7 @@ static inline bool xe_hw_engine_is_valid(struct xe_hw_engine *hwe)
 }
 
 const char *xe_hw_engine_class_to_str(enum xe_engine_class class);
-u64 xe_hw_engine_read_timestamp(struct xe_hw_engine *hwe);
+int xe_hw_engine_read_timestamp(struct xe_hw_engine *hwe, u64 *gpu_timestamp);
 enum xe_force_wake_domains xe_hw_engine_to_fw_domain(struct xe_hw_engine *hwe);
 
 void xe_hw_engine_mmio_write32(struct xe_hw_engine *hwe, struct xe_reg reg, u32 val);
-- 
2.31.1