1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2019 Intel Corporation
5  */
6 
7 #include <linux/list.h>
8 #include <linux/list_sort.h>
9 #include <linux/llist.h>
10 
11 #include "i915_drv.h"
12 #include "intel_engine.h"
13 #include "intel_engine_user.h"
14 
15 struct intel_engine_cs *
16 intel_engine_lookup_user(struct drm_i915_private *i915, u8 class, u8 instance)
17 {
18 	struct rb_node *p = i915->uabi_engines.rb_node;
19 
20 	while (p) {
21 		struct intel_engine_cs *it =
22 			rb_entry(p, typeof(*it), uabi_node);
23 
24 		if (class < it->uabi_class)
25 			p = p->rb_left;
26 		else if (class > it->uabi_class ||
27 			 instance > it->uabi_instance)
28 			p = p->rb_right;
29 		else if (instance < it->uabi_instance)
30 			p = p->rb_left;
31 		else
32 			return it;
33 	}
34 
35 	return NULL;
36 }
37 
38 void intel_engine_add_user(struct intel_engine_cs *engine)
39 {
40 	llist_add((struct llist_node *)&engine->uabi_node,
41 		  (struct llist_head *)&engine->i915->uabi_engines);
42 }
43 
44 static const u8 uabi_classes[] = {
45 	[RENDER_CLASS] = I915_ENGINE_CLASS_RENDER,
46 	[COPY_ENGINE_CLASS] = I915_ENGINE_CLASS_COPY,
47 	[VIDEO_DECODE_CLASS] = I915_ENGINE_CLASS_VIDEO,
48 	[VIDEO_ENHANCEMENT_CLASS] = I915_ENGINE_CLASS_VIDEO_ENHANCE,
49 };
50 
51 static int engine_cmp(void *priv, struct list_head *A, struct list_head *B)
52 {
53 	const struct intel_engine_cs *a =
54 		container_of((struct rb_node *)A, typeof(*a), uabi_node);
55 	const struct intel_engine_cs *b =
56 		container_of((struct rb_node *)B, typeof(*b), uabi_node);
57 
58 	if (uabi_classes[a->class] < uabi_classes[b->class])
59 		return -1;
60 	if (uabi_classes[a->class] > uabi_classes[b->class])
61 		return 1;
62 
63 	if (a->instance < b->instance)
64 		return -1;
65 	if (a->instance > b->instance)
66 		return 1;
67 
68 	return 0;
69 }
70 
71 static struct llist_node *get_engines(struct drm_i915_private *i915)
72 {
73 	return llist_del_all((struct llist_head *)&i915->uabi_engines);
74 }
75 
76 static void sort_engines(struct drm_i915_private *i915,
77 			 struct list_head *engines)
78 {
79 	struct llist_node *pos, *next;
80 
81 	llist_for_each_safe(pos, next, get_engines(i915)) {
82 		struct intel_engine_cs *engine =
83 			container_of((struct rb_node *)pos, typeof(*engine),
84 				     uabi_node);
85 		list_add((struct list_head *)&engine->uabi_node, engines);
86 	}
87 	list_sort(NULL, engines, engine_cmp);
88 }
89 
90 static void set_scheduler_caps(struct drm_i915_private *i915)
91 {
92 	static const struct {
93 		u8 engine;
94 		u8 sched;
95 	} map[] = {
96 #define MAP(x, y) { ilog2(I915_ENGINE_##x), ilog2(I915_SCHEDULER_CAP_##y) }
97 		MAP(HAS_PREEMPTION, PREEMPTION),
98 		MAP(HAS_SEMAPHORES, SEMAPHORES),
99 		MAP(SUPPORTS_STATS, ENGINE_BUSY_STATS),
100 #undef MAP
101 	};
102 	struct intel_engine_cs *engine;
103 	u32 enabled, disabled;
104 
105 	enabled = 0;
106 	disabled = 0;
107 	for_each_uabi_engine(engine, i915) { /* all engines must agree! */
108 		int i;
109 
110 		if (engine->schedule)
111 			enabled |= (I915_SCHEDULER_CAP_ENABLED |
112 				    I915_SCHEDULER_CAP_PRIORITY);
113 		else
114 			disabled |= (I915_SCHEDULER_CAP_ENABLED |
115 				     I915_SCHEDULER_CAP_PRIORITY);
116 
117 		for (i = 0; i < ARRAY_SIZE(map); i++) {
118 			if (engine->flags & BIT(map[i].engine))
119 				enabled |= BIT(map[i].sched);
120 			else
121 				disabled |= BIT(map[i].sched);
122 		}
123 	}
124 
125 	i915->caps.scheduler = enabled & ~disabled;
126 	if (!(i915->caps.scheduler & I915_SCHEDULER_CAP_ENABLED))
127 		i915->caps.scheduler = 0;
128 }
129 
130 const char *intel_engine_class_repr(u8 class)
131 {
132 	static const char * const uabi_names[] = {
133 		[RENDER_CLASS] = "rcs",
134 		[COPY_ENGINE_CLASS] = "bcs",
135 		[VIDEO_DECODE_CLASS] = "vcs",
136 		[VIDEO_ENHANCEMENT_CLASS] = "vecs",
137 	};
138 
139 	if (class >= ARRAY_SIZE(uabi_names) || !uabi_names[class])
140 		return "xxx";
141 
142 	return uabi_names[class];
143 }
144 
145 struct legacy_ring {
146 	struct intel_gt *gt;
147 	u8 class;
148 	u8 instance;
149 };
150 
151 static int legacy_ring_idx(const struct legacy_ring *ring)
152 {
153 	static const struct {
154 		u8 base, max;
155 	} map[] = {
156 		[RENDER_CLASS] = { RCS0, 1 },
157 		[COPY_ENGINE_CLASS] = { BCS0, 1 },
158 		[VIDEO_DECODE_CLASS] = { VCS0, I915_MAX_VCS },
159 		[VIDEO_ENHANCEMENT_CLASS] = { VECS0, I915_MAX_VECS },
160 	};
161 
162 	if (GEM_DEBUG_WARN_ON(ring->class >= ARRAY_SIZE(map)))
163 		return -1;
164 
165 	if (GEM_DEBUG_WARN_ON(ring->instance >= map[ring->class].max))
166 		return -1;
167 
168 	return map[ring->class].base + ring->instance;
169 }
170 
171 static void add_legacy_ring(struct legacy_ring *ring,
172 			    struct intel_engine_cs *engine)
173 {
174 	int idx;
175 
176 	if (engine->gt != ring->gt || engine->class != ring->class) {
177 		ring->gt = engine->gt;
178 		ring->class = engine->class;
179 		ring->instance = 0;
180 	}
181 
182 	idx = legacy_ring_idx(ring);
183 	if (unlikely(idx == -1))
184 		return;
185 
186 	GEM_BUG_ON(idx >= ARRAY_SIZE(ring->gt->engine));
187 	ring->gt->engine[idx] = engine;
188 	ring->instance++;
189 
190 	engine->legacy_idx = idx;
191 }
192 
193 void intel_engines_driver_register(struct drm_i915_private *i915)
194 {
195 	struct legacy_ring ring = {};
196 	u8 uabi_instances[4] = {};
197 	struct list_head *it, *next;
198 	struct rb_node **p, *prev;
199 	LIST_HEAD(engines);
200 
201 	sort_engines(i915, &engines);
202 
203 	prev = NULL;
204 	p = &i915->uabi_engines.rb_node;
205 	list_for_each_safe(it, next, &engines) {
206 		struct intel_engine_cs *engine =
207 			container_of((struct rb_node *)it, typeof(*engine),
208 				     uabi_node);
209 		char old[sizeof(engine->name)];
210 
211 		GEM_BUG_ON(engine->class >= ARRAY_SIZE(uabi_classes));
212 		engine->uabi_class = uabi_classes[engine->class];
213 
214 		GEM_BUG_ON(engine->uabi_class >= ARRAY_SIZE(uabi_instances));
215 		engine->uabi_instance = uabi_instances[engine->uabi_class]++;
216 
217 		/* Replace the internal name with the final user facing name */
218 		memcpy(old, engine->name, sizeof(engine->name));
219 		scnprintf(engine->name, sizeof(engine->name), "%s%u",
220 			  intel_engine_class_repr(engine->class),
221 			  engine->uabi_instance);
222 		DRM_DEBUG_DRIVER("renamed %s to %s\n", old, engine->name);
223 
224 		rb_link_node(&engine->uabi_node, prev, p);
225 		rb_insert_color(&engine->uabi_node, &i915->uabi_engines);
226 
227 		GEM_BUG_ON(intel_engine_lookup_user(i915,
228 						    engine->uabi_class,
229 						    engine->uabi_instance) != engine);
230 
231 		/* Fix up the mapping to match default execbuf::user_map[] */
232 		add_legacy_ring(&ring, engine);
233 
234 		prev = &engine->uabi_node;
235 		p = &prev->rb_right;
236 	}
237 
238 	if (IS_ENABLED(CONFIG_DRM_I915_SELFTESTS) &&
239 	    IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) {
240 		struct intel_engine_cs *engine;
241 		unsigned int isolation;
242 		int class, inst;
243 		int errors = 0;
244 
245 		for (class = 0; class < ARRAY_SIZE(uabi_instances); class++) {
246 			for (inst = 0; inst < uabi_instances[class]; inst++) {
247 				engine = intel_engine_lookup_user(i915,
248 								  class, inst);
249 				if (!engine) {
250 					pr_err("UABI engine not found for { class:%d, instance:%d }\n",
251 					       class, inst);
252 					errors++;
253 					continue;
254 				}
255 
256 				if (engine->uabi_class != class ||
257 				    engine->uabi_instance != inst) {
258 					pr_err("Wrong UABI engine:%s { class:%d, instance:%d } found for { class:%d, instance:%d }\n",
259 					       engine->name,
260 					       engine->uabi_class,
261 					       engine->uabi_instance,
262 					       class, inst);
263 					errors++;
264 					continue;
265 				}
266 			}
267 		}
268 
269 		/*
270 		 * Make sure that classes with multiple engine instances all
271 		 * share the same basic configuration.
272 		 */
273 		isolation = intel_engines_has_context_isolation(i915);
274 		for_each_uabi_engine(engine, i915) {
275 			unsigned int bit = BIT(engine->uabi_class);
276 			unsigned int expected = engine->default_state ? bit : 0;
277 
278 			if ((isolation & bit) != expected) {
279 				pr_err("mismatching default context state for class %d on engine %s\n",
280 				       engine->uabi_class, engine->name);
281 				errors++;
282 			}
283 		}
284 
285 		if (WARN(errors, "Invalid UABI engine mapping found"))
286 			i915->uabi_engines = RB_ROOT;
287 	}
288 
289 	set_scheduler_caps(i915);
290 }
291 
292 unsigned int intel_engines_has_context_isolation(struct drm_i915_private *i915)
293 {
294 	struct intel_engine_cs *engine;
295 	unsigned int which;
296 
297 	which = 0;
298 	for_each_uabi_engine(engine, i915)
299 		if (engine->default_state)
300 			which |= BIT(engine->uabi_class);
301 
302 	return which;
303 }
304