1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include <linux/list.h>
7 #include <linux/list_sort.h>
8 #include <linux/llist.h>
9 
10 #include "i915_drv.h"
11 #include "intel_engine.h"
12 #include "intel_engine_user.h"
13 #include "intel_gt.h"
14 #include "uc/intel_guc_submission.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 	/* TODO: Add COMPUTE_CLASS mapping once ABI is available */
51 };
52 
53 static int engine_cmp(void *priv, const struct list_head *A,
54 		      const struct list_head *B)
55 {
56 	const struct intel_engine_cs *a =
57 		container_of((struct rb_node *)A, typeof(*a), uabi_node);
58 	const struct intel_engine_cs *b =
59 		container_of((struct rb_node *)B, typeof(*b), uabi_node);
60 
61 	if (uabi_classes[a->class] < uabi_classes[b->class])
62 		return -1;
63 	if (uabi_classes[a->class] > uabi_classes[b->class])
64 		return 1;
65 
66 	if (a->instance < b->instance)
67 		return -1;
68 	if (a->instance > b->instance)
69 		return 1;
70 
71 	return 0;
72 }
73 
74 static struct llist_node *get_engines(struct drm_i915_private *i915)
75 {
76 	return llist_del_all((struct llist_head *)&i915->uabi_engines);
77 }
78 
79 static void sort_engines(struct drm_i915_private *i915,
80 			 struct list_head *engines)
81 {
82 	struct llist_node *pos, *next;
83 
84 	llist_for_each_safe(pos, next, get_engines(i915)) {
85 		struct intel_engine_cs *engine =
86 			container_of((struct rb_node *)pos, typeof(*engine),
87 				     uabi_node);
88 		list_add((struct list_head *)&engine->uabi_node, engines);
89 	}
90 	list_sort(NULL, engines, engine_cmp);
91 }
92 
93 static void set_scheduler_caps(struct drm_i915_private *i915)
94 {
95 	static const struct {
96 		u8 engine;
97 		u8 sched;
98 	} map[] = {
99 #define MAP(x, y) { ilog2(I915_ENGINE_##x), ilog2(I915_SCHEDULER_CAP_##y) }
100 		MAP(HAS_PREEMPTION, PREEMPTION),
101 		MAP(HAS_SEMAPHORES, SEMAPHORES),
102 		MAP(SUPPORTS_STATS, ENGINE_BUSY_STATS),
103 #undef MAP
104 	};
105 	struct intel_engine_cs *engine;
106 	u32 enabled, disabled;
107 
108 	enabled = 0;
109 	disabled = 0;
110 	for_each_uabi_engine(engine, i915) { /* all engines must agree! */
111 		int i;
112 
113 		if (engine->sched_engine->schedule)
114 			enabled |= (I915_SCHEDULER_CAP_ENABLED |
115 				    I915_SCHEDULER_CAP_PRIORITY);
116 		else
117 			disabled |= (I915_SCHEDULER_CAP_ENABLED |
118 				     I915_SCHEDULER_CAP_PRIORITY);
119 
120 		if (intel_uc_uses_guc_submission(&to_gt(i915)->uc))
121 			enabled |= I915_SCHEDULER_CAP_STATIC_PRIORITY_MAP;
122 
123 		for (i = 0; i < ARRAY_SIZE(map); i++) {
124 			if (engine->flags & BIT(map[i].engine))
125 				enabled |= BIT(map[i].sched);
126 			else
127 				disabled |= BIT(map[i].sched);
128 		}
129 	}
130 
131 	i915->caps.scheduler = enabled & ~disabled;
132 	if (!(i915->caps.scheduler & I915_SCHEDULER_CAP_ENABLED))
133 		i915->caps.scheduler = 0;
134 }
135 
136 const char *intel_engine_class_repr(u8 class)
137 {
138 	static const char * const uabi_names[] = {
139 		[RENDER_CLASS] = "rcs",
140 		[COPY_ENGINE_CLASS] = "bcs",
141 		[VIDEO_DECODE_CLASS] = "vcs",
142 		[VIDEO_ENHANCEMENT_CLASS] = "vecs",
143 		[COMPUTE_CLASS] = "ccs",
144 	};
145 
146 	if (class >= ARRAY_SIZE(uabi_names) || !uabi_names[class])
147 		return "xxx";
148 
149 	return uabi_names[class];
150 }
151 
152 struct legacy_ring {
153 	struct intel_gt *gt;
154 	u8 class;
155 	u8 instance;
156 };
157 
158 static int legacy_ring_idx(const struct legacy_ring *ring)
159 {
160 	static const struct {
161 		u8 base, max;
162 	} map[] = {
163 		[RENDER_CLASS] = { RCS0, 1 },
164 		[COPY_ENGINE_CLASS] = { BCS0, 1 },
165 		[VIDEO_DECODE_CLASS] = { VCS0, I915_MAX_VCS },
166 		[VIDEO_ENHANCEMENT_CLASS] = { VECS0, I915_MAX_VECS },
167 		[COMPUTE_CLASS] = { CCS0, I915_MAX_CCS },
168 	};
169 
170 	if (GEM_DEBUG_WARN_ON(ring->class >= ARRAY_SIZE(map)))
171 		return INVALID_ENGINE;
172 
173 	if (GEM_DEBUG_WARN_ON(ring->instance >= map[ring->class].max))
174 		return INVALID_ENGINE;
175 
176 	return map[ring->class].base + ring->instance;
177 }
178 
179 static void add_legacy_ring(struct legacy_ring *ring,
180 			    struct intel_engine_cs *engine)
181 {
182 	if (engine->gt != ring->gt || engine->class != ring->class) {
183 		ring->gt = engine->gt;
184 		ring->class = engine->class;
185 		ring->instance = 0;
186 	}
187 
188 	engine->legacy_idx = legacy_ring_idx(ring);
189 	if (engine->legacy_idx != INVALID_ENGINE)
190 		ring->instance++;
191 }
192 
193 void intel_engines_driver_register(struct drm_i915_private *i915)
194 {
195 	struct legacy_ring ring = {};
196 	struct list_head *it, *next;
197 	struct rb_node **p, *prev;
198 	LIST_HEAD(engines);
199 
200 	sort_engines(i915, &engines);
201 
202 	prev = NULL;
203 	p = &i915->uabi_engines.rb_node;
204 	list_for_each_safe(it, next, &engines) {
205 		struct intel_engine_cs *engine =
206 			container_of((struct rb_node *)it, typeof(*engine),
207 				     uabi_node);
208 		char old[sizeof(engine->name)];
209 
210 		if (intel_gt_has_unrecoverable_error(engine->gt))
211 			continue; /* ignore incomplete engines */
212 
213 		GEM_BUG_ON(engine->class >= ARRAY_SIZE(uabi_classes));
214 		engine->uabi_class = uabi_classes[engine->class];
215 
216 		GEM_BUG_ON(engine->uabi_class >=
217 			   ARRAY_SIZE(i915->engine_uabi_class_count));
218 		engine->uabi_instance =
219 			i915->engine_uabi_class_count[engine->uabi_class]++;
220 
221 		/* Replace the internal name with the final user facing name */
222 		memcpy(old, engine->name, sizeof(engine->name));
223 		scnprintf(engine->name, sizeof(engine->name), "%s%u",
224 			  intel_engine_class_repr(engine->class),
225 			  engine->uabi_instance);
226 		DRM_DEBUG_DRIVER("renamed %s to %s\n", old, engine->name);
227 
228 		rb_link_node(&engine->uabi_node, prev, p);
229 		rb_insert_color(&engine->uabi_node, &i915->uabi_engines);
230 
231 		GEM_BUG_ON(intel_engine_lookup_user(i915,
232 						    engine->uabi_class,
233 						    engine->uabi_instance) != engine);
234 
235 		/* Fix up the mapping to match default execbuf::user_map[] */
236 		add_legacy_ring(&ring, engine);
237 
238 		prev = &engine->uabi_node;
239 		p = &prev->rb_right;
240 	}
241 
242 	if (IS_ENABLED(CONFIG_DRM_I915_SELFTESTS) &&
243 	    IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) {
244 		struct intel_engine_cs *engine;
245 		unsigned int isolation;
246 		int class, inst;
247 		int errors = 0;
248 
249 		for (class = 0; class < ARRAY_SIZE(i915->engine_uabi_class_count); class++) {
250 			for (inst = 0; inst < i915->engine_uabi_class_count[class]; inst++) {
251 				engine = intel_engine_lookup_user(i915,
252 								  class, inst);
253 				if (!engine) {
254 					pr_err("UABI engine not found for { class:%d, instance:%d }\n",
255 					       class, inst);
256 					errors++;
257 					continue;
258 				}
259 
260 				if (engine->uabi_class != class ||
261 				    engine->uabi_instance != inst) {
262 					pr_err("Wrong UABI engine:%s { class:%d, instance:%d } found for { class:%d, instance:%d }\n",
263 					       engine->name,
264 					       engine->uabi_class,
265 					       engine->uabi_instance,
266 					       class, inst);
267 					errors++;
268 					continue;
269 				}
270 			}
271 		}
272 
273 		/*
274 		 * Make sure that classes with multiple engine instances all
275 		 * share the same basic configuration.
276 		 */
277 		isolation = intel_engines_has_context_isolation(i915);
278 		for_each_uabi_engine(engine, i915) {
279 			unsigned int bit = BIT(engine->uabi_class);
280 			unsigned int expected = engine->default_state ? bit : 0;
281 
282 			if ((isolation & bit) != expected) {
283 				pr_err("mismatching default context state for class %d on engine %s\n",
284 				       engine->uabi_class, engine->name);
285 				errors++;
286 			}
287 		}
288 
289 		if (drm_WARN(&i915->drm, errors,
290 			     "Invalid UABI engine mapping found"))
291 			i915->uabi_engines = RB_ROOT;
292 	}
293 
294 	set_scheduler_caps(i915);
295 }
296 
297 unsigned int intel_engines_has_context_isolation(struct drm_i915_private *i915)
298 {
299 	struct intel_engine_cs *engine;
300 	unsigned int which;
301 
302 	which = 0;
303 	for_each_uabi_engine(engine, i915)
304 		if (engine->default_state)
305 			which |= BIT(engine->uabi_class);
306 
307 	return which;
308 }
309