drm/i915: Small compaction of the engine init code

Effectively removes one layer of indirection between the mask of
possible engines and the engine constructors. Instead of spelling
out in code the mapping of HAS_<engine> to constructors, makes
more use of the recently added data driven approach by putting
engine constructor vfuncs into the table as well.

Effect is fewer lines of source and smaller binary.

At the same time simplify the error handling since engine
destructors can run on unitialized engines anyway.

Similar approach could be done for legacy submission is wanted.

v2: Removed ugly BUILD_BUG_ONs in favour of newly introduced
    ENGINE_MASK and HAS_ENGINE macros.
    Also removed the forward declarations by shuffling functions
    around.

v3: Warn when logical_rings table does not contain enough data
    and disable the engines which could not be initialized.
    (Chris Wilson)

v4: Chris Wilson suggested a nicer engine init loop.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1466689961-23232-1-git-send-email-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -2759,17 +2759,22 @@ struct drm_i915_cmd_table {
 #define IS_GEN8(dev)	(INTEL_INFO(dev)->gen_mask & BIT(7))
 #define IS_GEN9(dev)	(INTEL_INFO(dev)->gen_mask & BIT(8))
 
-#define RENDER_RING		(1<<RCS)
-#define BSD_RING		(1<<VCS)
-#define BLT_RING		(1<<BCS)
-#define VEBOX_RING		(1<<VECS)
-#define BSD2_RING		(1<<VCS2)
-#define ALL_ENGINES		(~0)
-
-#define HAS_BSD(dev)		(INTEL_INFO(dev)->ring_mask & BSD_RING)
-#define HAS_BSD2(dev)		(INTEL_INFO(dev)->ring_mask & BSD2_RING)
-#define HAS_BLT(dev)		(INTEL_INFO(dev)->ring_mask & BLT_RING)
-#define HAS_VEBOX(dev)		(INTEL_INFO(dev)->ring_mask & VEBOX_RING)
+#define ENGINE_MASK(id)	BIT(id)
+#define RENDER_RING	ENGINE_MASK(RCS)
+#define BSD_RING	ENGINE_MASK(VCS)
+#define BLT_RING	ENGINE_MASK(BCS)
+#define VEBOX_RING	ENGINE_MASK(VECS)
+#define BSD2_RING	ENGINE_MASK(VCS2)
+#define ALL_ENGINES	(~0)
+
+#define HAS_ENGINE(dev_priv, id) \
+	(INTEL_INFO(dev_priv)->ring_mask & ENGINE_MASK(id))
+
+#define HAS_BSD(dev_priv)	HAS_ENGINE(dev_priv, VCS)
+#define HAS_BSD2(dev_priv)	HAS_ENGINE(dev_priv, VCS2)
+#define HAS_BLT(dev_priv)	HAS_ENGINE(dev_priv, BCS)
+#define HAS_VEBOX(dev_priv)	HAS_ENGINE(dev_priv, VECS)
+
 #define HAS_LLC(dev)		(INTEL_INFO(dev)->has_llc)
 #define HAS_SNOOP(dev)		(INTEL_INFO(dev)->has_snoop)
 #define HAS_EDRAM(dev)		(__I915__(dev)->edram_cap & EDRAM_ENABLED)

drivers/gpu/drm/i915/intel_lrc.c

@@ -2016,12 +2016,90 @@ lrc_setup_hws(struct intel_engine_cs *engine,
 	return 0;
 }
 
+static int
+logical_ring_init(struct intel_engine_cs *engine)
+{
+	struct i915_gem_context *dctx = engine->i915->kernel_context;
+	int ret;
+
+	ret = i915_cmd_parser_init_ring(engine);
+	if (ret)
+		goto error;
+
+	ret = execlists_context_deferred_alloc(dctx, engine);
+	if (ret)
+		goto error;
+
+	/* As this is the default context, always pin it */
+	ret = intel_lr_context_pin(dctx, engine);
+	if (ret) {
+		DRM_ERROR("Failed to pin context for %s: %d\n",
+			  engine->name, ret);
+		goto error;
+	}
+
+	/* And setup the hardware status page. */
+	ret = lrc_setup_hws(engine, dctx->engine[engine->id].state);
+	if (ret) {
+		DRM_ERROR("Failed to set up hws %s: %d\n", engine->name, ret);
+		goto error;
+	}
+
+	return 0;
+
+error:
+	intel_logical_ring_cleanup(engine);
+	return ret;
+}
+
+static int logical_render_ring_init(struct intel_engine_cs *engine)
+{
+	struct drm_i915_private *dev_priv = engine->i915;
+	int ret;
+
+	if (HAS_L3_DPF(dev_priv))
+		engine->irq_keep_mask |= GT_RENDER_L3_PARITY_ERROR_INTERRUPT;
+
+	/* Override some for render ring. */
+	if (INTEL_GEN(dev_priv) >= 9)
+		engine->init_hw = gen9_init_render_ring;
+	else
+		engine->init_hw = gen8_init_render_ring;
+	engine->init_context = gen8_init_rcs_context;
+	engine->cleanup = intel_fini_pipe_control;
+	engine->emit_flush = gen8_emit_flush_render;
+	engine->emit_request = gen8_emit_request_render;
+
+	ret = intel_init_pipe_control(engine);
+	if (ret)
+		return ret;
+
+	ret = intel_init_workaround_bb(engine);
+	if (ret) {
+		/*
+		 * We continue even if we fail to initialize WA batch
+		 * because we only expect rare glitches but nothing
+		 * critical to prevent us from using GPU
+		 */
+		DRM_ERROR("WA batch buffer initialization failed: %d\n",
+			  ret);
+	}
+
+	ret = logical_ring_init(engine);
+	if (ret) {
+		lrc_destroy_wa_ctx_obj(engine);
+	}
+
+	return ret;
+}
+
 static const struct logical_ring_info {
 	const char *name;
 	unsigned exec_id;
 	unsigned guc_id;
 	u32 mmio_base;
 	unsigned irq_shift;
+	int (*init)(struct intel_engine_cs *engine);
 } logical_rings[] = {
 	[RCS] = {
 		.name = "render ring",
@@ -2029,6 +2107,7 @@ static const struct logical_ring_info {
 		.guc_id = GUC_RENDER_ENGINE,
 		.mmio_base = RENDER_RING_BASE,
 		.irq_shift = GEN8_RCS_IRQ_SHIFT,
+		.init = logical_render_ring_init,
 	},
 	[BCS] = {
 		.name = "blitter ring",
@@ -2036,6 +2115,7 @@ static const struct logical_ring_info {
 		.guc_id = GUC_BLITTER_ENGINE,
 		.mmio_base = BLT_RING_BASE,
 		.irq_shift = GEN8_BCS_IRQ_SHIFT,
+		.init = logical_ring_init,
 	},
 	[VCS] = {
 		.name = "bsd ring",
@@ -2043,6 +2123,7 @@ static const struct logical_ring_info {
 		.guc_id = GUC_VIDEO_ENGINE,
 		.mmio_base = GEN6_BSD_RING_BASE,
 		.irq_shift = GEN8_VCS1_IRQ_SHIFT,
+		.init = logical_ring_init,
 	},
 	[VCS2] = {
 		.name = "bsd2 ring",
@@ -2050,6 +2131,7 @@ static const struct logical_ring_info {
 		.guc_id = GUC_VIDEO_ENGINE2,
 		.mmio_base = GEN8_BSD2_RING_BASE,
 		.irq_shift = GEN8_VCS2_IRQ_SHIFT,
+		.init = logical_ring_init,
 	},
 	[VECS] = {
 		.name = "video enhancement ring",
@@ -2057,14 +2139,14 @@ static const struct logical_ring_info {
 		.guc_id = GUC_VIDEOENHANCE_ENGINE,
 		.mmio_base = VEBOX_RING_BASE,
 		.irq_shift = GEN8_VECS_IRQ_SHIFT,
+		.init = logical_ring_init,
 	},
 };
 
 static struct intel_engine_cs *
-logical_ring_setup(struct drm_device *dev, enum intel_engine_id id)
+logical_ring_setup(struct drm_i915_private *dev_priv, enum intel_engine_id id)
 {
 	const struct logical_ring_info *info = &logical_rings[id];
-	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_engine_cs *engine = &dev_priv->engine[id];
 	enum forcewake_domains fw_domains;
 
@@ -2107,169 +2189,62 @@ logical_ring_setup(struct drm_device *dev, enum intel_engine_id id)
 	logical_ring_default_irqs(engine, info->irq_shift);
 
 	intel_engine_init_hangcheck(engine);
-	i915_gem_batch_pool_init(dev, &engine->batch_pool);
+	i915_gem_batch_pool_init(dev_priv->dev, &engine->batch_pool);
 
 	return engine;
 }
 
-static int
-logical_ring_init(struct intel_engine_cs *engine)
-{
-	struct i915_gem_context *dctx = engine->i915->kernel_context;
-	int ret;
-
-	ret = i915_cmd_parser_init_ring(engine);
-	if (ret)
-		goto error;
-
-	ret = execlists_context_deferred_alloc(dctx, engine);
-	if (ret)
-		goto error;
-
-	/* As this is the default context, always pin it */
-	ret = intel_lr_context_pin(dctx, engine);
-	if (ret) {
-		DRM_ERROR("Failed to pin context for %s: %d\n",
-			  engine->name, ret);
-		goto error;
-	}
-
-	/* And setup the hardware status page. */
-	ret = lrc_setup_hws(engine, dctx->engine[engine->id].state);
-	if (ret) {
-		DRM_ERROR("Failed to set up hws %s: %d\n", engine->name, ret);
-		goto error;
-	}
-
-	return 0;
-
-error:
-	intel_logical_ring_cleanup(engine);
-	return ret;
-}
-
-static int logical_render_ring_init(struct drm_device *dev)
-{
-	struct intel_engine_cs *engine = logical_ring_setup(dev, RCS);
-	int ret;
-
-	if (HAS_L3_DPF(dev))
-		engine->irq_keep_mask |= GT_RENDER_L3_PARITY_ERROR_INTERRUPT;
-
-	/* Override some for render ring. */
-	if (INTEL_INFO(dev)->gen >= 9)
-		engine->init_hw = gen9_init_render_ring;
-	else
-		engine->init_hw = gen8_init_render_ring;
-	engine->init_context = gen8_init_rcs_context;
-	engine->cleanup = intel_fini_pipe_control;
-	engine->emit_flush = gen8_emit_flush_render;
-	engine->emit_request = gen8_emit_request_render;
-
-	ret = intel_init_pipe_control(engine);
-	if (ret)
-		return ret;
-
-	ret = intel_init_workaround_bb(engine);
-	if (ret) {
-		/*
-		 * We continue even if we fail to initialize WA batch
-		 * because we only expect rare glitches but nothing
-		 * critical to prevent us from using GPU
-		 */
-		DRM_ERROR("WA batch buffer initialization failed: %d\n",
-			  ret);
-	}
-
-	ret = logical_ring_init(engine);
-	if (ret) {
-		lrc_destroy_wa_ctx_obj(engine);
-	}
-
-	return ret;
-}
-
-static int logical_bsd_ring_init(struct drm_device *dev)
-{
-	struct intel_engine_cs *engine = logical_ring_setup(dev, VCS);
-
-	return logical_ring_init(engine);
-}
-
-static int logical_bsd2_ring_init(struct drm_device *dev)
-{
-	struct intel_engine_cs *engine = logical_ring_setup(dev, VCS2);
-
-	return logical_ring_init(engine);
-}
-
-static int logical_blt_ring_init(struct drm_device *dev)
-{
-	struct intel_engine_cs *engine = logical_ring_setup(dev, BCS);
-
-	return logical_ring_init(engine);
-}
-
-static int logical_vebox_ring_init(struct drm_device *dev)
-{
-	struct intel_engine_cs *engine = logical_ring_setup(dev, VECS);
-
-	return logical_ring_init(engine);
-}
-
 /**
  * intel_logical_rings_init() - allocate, populate and init the Engine Command Streamers
  * @dev: DRM device.
  *
- * This function inits the engines for an Execlists submission style (the equivalent in the
- * legacy ringbuffer submission world would be i915_gem_init_engines). It does it only for
- * those engines that are present in the hardware.
+ * This function inits the engines for an Execlists submission style (the
+ * equivalent in the legacy ringbuffer submission world would be
+ * i915_gem_init_engines). It does it only for those engines that are present in
+ * the hardware.
  *
  * Return: non-zero if the initialization failed.
  */
 int intel_logical_rings_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned int mask = 0;
+	unsigned int i;
 	int ret;
 
-	ret = logical_render_ring_init(dev);
-	if (ret)
-		return ret;
+	WARN_ON(INTEL_INFO(dev_priv)->ring_mask &
+		GENMASK(sizeof(mask) * BITS_PER_BYTE - 1, I915_NUM_ENGINES));
 
-	if (HAS_BSD(dev)) {
-		ret = logical_bsd_ring_init(dev);
-		if (ret)
-			goto cleanup_render_ring;
-	}
+	for (i = 0; i < ARRAY_SIZE(logical_rings); i++) {
+		if (!HAS_ENGINE(dev_priv, i))
+			continue;
 
-	if (HAS_BLT(dev)) {
-		ret = logical_blt_ring_init(dev);
-		if (ret)
-			goto cleanup_bsd_ring;
-	}
+		if (!logical_rings[i].init)
+			continue;
 
-	if (HAS_VEBOX(dev)) {
-		ret = logical_vebox_ring_init(dev);
+		ret = logical_rings[i].init(logical_ring_setup(dev_priv, i));
 		if (ret)
-			goto cleanup_blt_ring;
+			goto cleanup;
+
+		mask |= ENGINE_MASK(i);
 	}
 
-	if (HAS_BSD2(dev)) {
-		ret = logical_bsd2_ring_init(dev);
-		if (ret)
-			goto cleanup_vebox_ring;
+	/*
+	 * Catch failures to update logical_rings table when the new engines
+	 * are added to the driver by a warning and disabling the forgotten
+	 * engines.
+	 */
+	if (WARN_ON(mask != INTEL_INFO(dev_priv)->ring_mask)) {
+		struct intel_device_info *info =
+			(struct intel_device_info *)&dev_priv->info;
+		info->ring_mask = mask;
 	}
 
 	return 0;
 
-cleanup_vebox_ring:
-	intel_logical_ring_cleanup(&dev_priv->engine[VECS]);
-cleanup_blt_ring:
-	intel_logical_ring_cleanup(&dev_priv->engine[BCS]);
-cleanup_bsd_ring:
-	intel_logical_ring_cleanup(&dev_priv->engine[VCS]);
-cleanup_render_ring:
-	intel_logical_ring_cleanup(&dev_priv->engine[RCS]);
+cleanup:
+	for (i = 0; i < I915_NUM_ENGINES; i++)
+		intel_logical_ring_cleanup(&dev_priv->engine[i]);
 
 	return ret;
 }