drm/xe: Add CONFIG_DRM_XE_PREEMPT_TIMEOUT

Allow preemption timeout to be specified as a config option.

v2: Change unit to microseconds (Tejas)
v3: Remove get_default_preempt_timeout()
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/Kconfig.profile

@@ -22,6 +22,14 @@ config DRM_XE_TIMESLICE_MIN
 	help
 	  Configures the default min timeslice duration between multiple
 	  contexts by guc scheduling.
+config DRM_XE_PREEMPT_TIMEOUT
+	int "Preempt timeout (us, jiffy granularity)"
+	default 640000 # microseconds
+	help
+	  How long to wait (in microseconds) for a preemption event to occur
+	  when submitting a new context. If the current context does not hit
+	  an arbitration point and yield to HW before the timer expires, the
+	  HW will be reset to allow the more important context to execute.
 config DRM_XE_PREEMPT_TIMEOUT_MAX
 	int "Default max preempt timeout (us)"
 	default 10000000 # microseconds

drivers/gpu/drm/xe/xe_hw_engine.c

@@ -370,7 +370,7 @@ static void hw_engine_init_early(struct xe_gt *gt, struct xe_hw_engine *hwe,
 		hwe->eclass->sched_props.timeslice_us = 1 * 1000;
 		hwe->eclass->sched_props.timeslice_min = XE_HW_ENGINE_TIMESLICE_MIN;
 		hwe->eclass->sched_props.timeslice_max = XE_HW_ENGINE_TIMESLICE_MAX;
-		hwe->eclass->sched_props.preempt_timeout_us = 640 * 1000;
+		hwe->eclass->sched_props.preempt_timeout_us = XE_HW_ENGINE_PREEMPT_TIMEOUT;
 		hwe->eclass->sched_props.preempt_timeout_min = XE_HW_ENGINE_PREEMPT_TIMEOUT_MIN;
 		hwe->eclass->sched_props.preempt_timeout_max = XE_HW_ENGINE_PREEMPT_TIMEOUT_MAX;
 		/* Record default props */
@@ -562,6 +562,9 @@ int xe_hw_engines_init_early(struct xe_gt *gt)
 	read_copy_fuses(gt);
 	read_compute_fuses(gt);
 
+	BUILD_BUG_ON(XE_HW_ENGINE_PREEMPT_TIMEOUT < XE_HW_ENGINE_PREEMPT_TIMEOUT_MIN);
+	BUILD_BUG_ON(XE_HW_ENGINE_PREEMPT_TIMEOUT > XE_HW_ENGINE_PREEMPT_TIMEOUT_MAX);
+
 	for (i = 0; i < ARRAY_SIZE(gt->hw_engines); i++)
 		hw_engine_init_early(gt, &gt->hw_engines[i], i);
 

drivers/gpu/drm/xe/xe_hw_engine.h

@@ -30,6 +30,11 @@ struct drm_printer;
 #else
 #define XE_HW_ENGINE_TIMESLICE_MAX (10 * 1000 * 1000)
 #endif
+#ifdef CONFIG_DRM_XE_PREEMPT_TIMEOUT
+#define XE_HW_ENGINE_PREEMPT_TIMEOUT CONFIG_DRM_XE_PREEMPT_TIMEOUT
+#else
+#define XE_HW_ENGINE_PREEMPT_TIMEOUT (640 * 1000)
+#endif
 #ifdef CONFIG_DRM_XE_PREEMPT_TIMEOUT_MIN
 #define XE_HW_ENGINE_PREEMPT_TIMEOUT_MIN CONFIG_DRM_XE_PREEMPT_TIMEOUT_MIN
 #else