[Intel-gfx] [PATCH] drm/i915: Use the precomputed value for whether to enable command parsing

[Chris Wilson]

As i915.enable_cmd_parser is an unsafe option, make it read-only at
runtime. Now that it is constant, we can use the value determined during
initialisation as to whether we need the cmdparser at execbuffer time.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_cmd_parser.c  | 21 ---------------------
 drivers/gpu/drm/i915/i915_drv.h         |  1 -
 drivers/gpu/drm/i915/i915_params.c      |  6 +++---
 drivers/gpu/drm/i915/i915_params.h      |  2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.h | 15 +++++++++++++++
 5 files changed, 19 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 6a35ccf4f8ab..7d91ef2d86c7 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -1032,27 +1032,6 @@ static u32 *copy_batch(struct drm_i915_gem_object *dst_obj,
 	return dst;
 }
 
-/**
- * intel_engine_needs_cmd_parser() - should a given engine use software
- *                                   command parsing?
- * @engine: the engine in question
- *
- * Only certain platforms require software batch buffer command parsing, and
- * only when enabled via module parameter.
- *
- * Return: true if the engine requires software command parsing
- */
-bool intel_engine_needs_cmd_parser(struct intel_engine_cs *engine)
-{
-	if (!engine->needs_cmd_parser)
-		return false;
-
-	if (!USES_PPGTT(engine->i915))
-		return false;
-
-	return (i915.enable_cmd_parser == 1);
-}
-
 static bool check_cmd(const struct intel_engine_cs *engine,
 		      const struct drm_i915_cmd_descriptor *desc,
 		      const u32 *cmd, u32 length,
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 239dda8d6815..6b1804143816 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3539,7 +3539,6 @@ const char *i915_cache_level_str(struct drm_i915_private *i915, int type);
 int i915_cmd_parser_get_version(struct drm_i915_private *dev_priv);
 void intel_engine_init_cmd_parser(struct intel_engine_cs *engine);
 void intel_engine_cleanup_cmd_parser(struct intel_engine_cs *engine);
-bool intel_engine_needs_cmd_parser(struct intel_engine_cs *engine);
 int intel_engine_cmd_parser(struct intel_engine_cs *engine,
 			    struct drm_i915_gem_object *batch_obj,
 			    struct drm_i915_gem_object *shadow_batch_obj,
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 599b913d8906..ef1e9921a2af 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -50,7 +50,7 @@ struct i915_params i915 __read_mostly = {
 	.error_capture = true,
 	.invert_brightness = 0,
 	.disable_display = 0,
-	.enable_cmd_parser = 1,
+	.enable_cmd_parser = true,
 	.use_mmio_flip = 0,
 	.mmio_debug = 0,
 	.verbose_state_checks = 1,
@@ -188,9 +188,9 @@ MODULE_PARM_DESC(invert_brightness,
 module_param_named(disable_display, i915.disable_display, bool, 0400);
 MODULE_PARM_DESC(disable_display, "Disable display (default: false)");
 
-module_param_named_unsafe(enable_cmd_parser, i915.enable_cmd_parser, int, 0600);
+module_param_named_unsafe(enable_cmd_parser, i915.enable_cmd_parser, bool, 0400);
 MODULE_PARM_DESC(enable_cmd_parser,
-		 "Enable command parsing (1=enabled [default], 0=disabled)");
+		 "Enable command parsing (true=enabled [default], false=disabled)");
 
 module_param_named_unsafe(use_mmio_flip, i915.use_mmio_flip, int, 0600);
 MODULE_PARM_DESC(use_mmio_flip,
diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index 817ad959941e..8e433de04679 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -44,7 +44,6 @@ struct i915_params {
 	int disable_power_well;
 	int enable_ips;
 	int invert_brightness;
-	int enable_cmd_parser;
 	int enable_guc_loading;
 	int enable_guc_submission;
 	int guc_log_level;
@@ -53,6 +52,7 @@ struct i915_params {
 	int edp_vswing;
 	unsigned int inject_load_failure;
 	/* leave bools at the end to not create holes */
+	bool enable_cmd_parser;
 	bool enable_hangcheck;
 	bool fastboot;
 	bool prefault_disable;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index f8249c4a70d8..32238592d896 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -418,6 +418,21 @@ intel_engine_flag(const struct intel_engine_cs *engine)
 	return 1 << engine->id;
 }
 
+/**
+ * intel_engine_needs_cmd_parser() - should a given engine use software
+ *                                   command parsing?
+ * @engine: the engine in question
+ *
+ * Only certain platforms require software batch buffer command parsing, and
+ * only when enabled via module parameter.
+ *
+ * Return: true if the engine requires software command parsing
+ */
+static inline bool intel_engine_needs_cmd_parser(struct intel_engine_cs *engine)
+{
+	return engine->needs_cmd_parser;
+}
+
 static inline void
 intel_flush_status_page(struct intel_engine_cs *engine, int reg)
 {
-- 
2.10.2