drm/i915: Split the engine info table in two levels, using class + instance

There are some properties that logically belong to the engine class, and some
that belong to the engine instance. Make it explicit.

v2: Commit message (Tvrtko)

v3:
  - Rebased
  - Exec/uabi id should be per instance (Chris)

v4:
  - Rebased
  - Avoid re-ordering fields for smaller diff (Tvrtko)
  - Bug on oob access to the class array (Michal)

v5: Bug on the right thing (Michal)

v6: Rebased

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-5-git-send-email-oscar.mateo@intel.com
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/intel_engine_cs.c

@@ -26,71 +26,84 @@
 #include "intel_ringbuffer.h"
 #include "intel_lrc.h"
 
-static const struct engine_info {
+struct engine_class_info {
 	const char *name;
-	unsigned int exec_id;
+	int (*init_legacy)(struct intel_engine_cs *engine);
+	int (*init_execlists)(struct intel_engine_cs *engine);
+};
+
+static const struct engine_class_info intel_engine_classes[] = {
+	[RENDER_CLASS] = {
+		.name = "rcs",
+		.init_execlists = logical_render_ring_init,
+		.init_legacy = intel_init_render_ring_buffer,
+	},
+	[COPY_ENGINE_CLASS] = {
+		.name = "bcs",
+		.init_execlists = logical_xcs_ring_init,
+		.init_legacy = intel_init_blt_ring_buffer,
+	},
+	[VIDEO_DECODE_CLASS] = {
+		.name = "vcs",
+		.init_execlists = logical_xcs_ring_init,
+		.init_legacy = intel_init_bsd_ring_buffer,
+	},
+	[VIDEO_ENHANCEMENT_CLASS] = {
+		.name = "vecs",
+		.init_execlists = logical_xcs_ring_init,
+		.init_legacy = intel_init_vebox_ring_buffer,
+	},
+};
+
+struct engine_info {
 	unsigned int hw_id;
+	unsigned int exec_id;
 	u8 class;
 	u8 instance;
 	u32 mmio_base;
 	unsigned irq_shift;
-	int (*init_legacy)(struct intel_engine_cs *engine);
-	int (*init_execlists)(struct intel_engine_cs *engine);
-} intel_engines[] = {
+};
+
+static const struct engine_info intel_engines[] = {
 	[RCS] = {
-		.name = "rcs",
 		.hw_id = RCS_HW,
 		.exec_id = I915_EXEC_RENDER,
 		.class = RENDER_CLASS,
 		.instance = 0,
 		.mmio_base = RENDER_RING_BASE,
 		.irq_shift = GEN8_RCS_IRQ_SHIFT,
-		.init_execlists = logical_render_ring_init,
-		.init_legacy = intel_init_render_ring_buffer,
 	},
 	[BCS] = {
-		.name = "bcs",
 		.hw_id = BCS_HW,
 		.exec_id = I915_EXEC_BLT,
 		.class = COPY_ENGINE_CLASS,
 		.instance = 0,
 		.mmio_base = BLT_RING_BASE,
 		.irq_shift = GEN8_BCS_IRQ_SHIFT,
-		.init_execlists = logical_xcs_ring_init,
-		.init_legacy = intel_init_blt_ring_buffer,
 	},
 	[VCS] = {
-		.name = "vcs",
 		.hw_id = VCS_HW,
 		.exec_id = I915_EXEC_BSD,
 		.class = VIDEO_DECODE_CLASS,
 		.instance = 0,
 		.mmio_base = GEN6_BSD_RING_BASE,
 		.irq_shift = GEN8_VCS1_IRQ_SHIFT,
-		.init_execlists = logical_xcs_ring_init,
-		.init_legacy = intel_init_bsd_ring_buffer,
 	},
 	[VCS2] = {
-		.name = "vcs",
 		.hw_id = VCS2_HW,
 		.exec_id = I915_EXEC_BSD,
 		.class = VIDEO_DECODE_CLASS,
 		.instance = 1,
 		.mmio_base = GEN8_BSD2_RING_BASE,
 		.irq_shift = GEN8_VCS2_IRQ_SHIFT,
-		.init_execlists = logical_xcs_ring_init,
-		.init_legacy = intel_init_bsd_ring_buffer,
 	},
 	[VECS] = {
-		.name = "vecs",
 		.hw_id = VECS_HW,
 		.exec_id = I915_EXEC_VEBOX,
 		.class = VIDEO_ENHANCEMENT_CLASS,
 		.instance = 0,
 		.mmio_base = VEBOX_RING_BASE,
 		.irq_shift = GEN8_VECS_IRQ_SHIFT,
-		.init_execlists = logical_xcs_ring_init,
-		.init_legacy = intel_init_vebox_ring_buffer,
 	},
 };
 
@@ -99,8 +112,12 @@ intel_engine_setup(struct drm_i915_private *dev_priv,
 		   enum intel_engine_id id)
 {
 	const struct engine_info *info = &intel_engines[id];
+	const struct engine_class_info *class_info;
 	struct intel_engine_cs *engine;
 
+	GEM_BUG_ON(info->class >= ARRAY_SIZE(intel_engine_classes));
+	class_info = &intel_engine_classes[info->class];
+
 	GEM_BUG_ON(dev_priv->engine[id]);
 	engine = kzalloc(sizeof(*engine), GFP_KERNEL);
 	if (!engine)
@@ -109,7 +126,8 @@ intel_engine_setup(struct drm_i915_private *dev_priv,
 	engine->id = id;
 	engine->i915 = dev_priv;
 	WARN_ON(snprintf(engine->name, sizeof(engine->name), "%s%u",
-			 info->name, info->instance) >= sizeof(engine->name));
+			 class_info->name, info->instance) >=
+		sizeof(engine->name));
 	engine->exec_id = info->exec_id;
 	engine->hw_id = engine->guc_id = info->hw_id;
 	engine->mmio_base = info->mmio_base;
@@ -190,12 +208,14 @@ int intel_engines_init(struct drm_i915_private *dev_priv)
 	int err = 0;
 
 	for_each_engine(engine, dev_priv, id) {
+		const struct engine_class_info *class_info =
+			&intel_engine_classes[engine->class];
 		int (*init)(struct intel_engine_cs *engine);
 
 		if (i915.enable_execlists)
-			init = intel_engines[id].init_execlists;
+			init = class_info->init_execlists;
 		else
-			init = intel_engines[id].init_legacy;
+			init = class_info->init_legacy;
 		if (!init) {
 			kfree(engine);
 			dev_priv->engine[id] = NULL;