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