xref: /linux/drivers/gpu/drm/i915/display/intel_global_state.c (revision 2697b79a469b68e3ad3640f55284359c1396278d) 
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  */
5 
6 #include <linux/string.h>
7 
8 #include "i915_drv.h"
9 #include "intel_atomic.h"
10 #include "intel_display_types.h"
11 #include "intel_global_state.h"
12 
13 struct intel_global_commit {
14 	struct kref ref;
15 	struct completion done;
16 };
17 
18 static struct intel_global_commit *commit_new(void)
19 {
20 	struct intel_global_commit *commit;
21 
22 	commit = kzalloc(sizeof(*commit), GFP_KERNEL);
23 	if (!commit)
24 		return NULL;
25 
26 	init_completion(&commit->done);
27 	kref_init(&commit->ref);
28 
29 	return commit;
30 }
31 
32 static void __commit_free(struct kref *kref)
33 {
34 	struct intel_global_commit *commit =
35 		container_of(kref, typeof(*commit), ref);
36 
37 	kfree(commit);
38 }
39 
40 static struct intel_global_commit *commit_get(struct intel_global_commit *commit)
41 {
42 	if (commit)
43 		kref_get(&commit->ref);
44 
45 	return commit;
46 }
47 
48 static void commit_put(struct intel_global_commit *commit)
49 {
50 	if (commit)
51 		kref_put(&commit->ref, __commit_free);
52 }
53 
54 static void __intel_atomic_global_state_free(struct kref *kref)
55 {
56 	struct intel_global_state *obj_state =
57 		container_of(kref, struct intel_global_state, ref);
58 	struct intel_global_obj *obj = obj_state->obj;
59 
60 	commit_put(obj_state->commit);
61 
62 	obj->funcs->atomic_destroy_state(obj, obj_state);
63 }
64 
65 static void intel_atomic_global_state_put(struct intel_global_state *obj_state)
66 {
67 	kref_put(&obj_state->ref, __intel_atomic_global_state_free);
68 }
69 
70 static struct intel_global_state *
71 intel_atomic_global_state_get(struct intel_global_state *obj_state)
72 {
73 	kref_get(&obj_state->ref);
74 
75 	return obj_state;
76 }
77 
78 void intel_atomic_global_obj_init(struct drm_i915_private *dev_priv,
79 				  struct intel_global_obj *obj,
80 				  struct intel_global_state *state,
81 				  const struct intel_global_state_funcs *funcs)
82 {
83 	memset(obj, 0, sizeof(*obj));
84 
85 	state->obj = obj;
86 
87 	kref_init(&state->ref);
88 
89 	obj->state = state;
90 	obj->funcs = funcs;
91 	list_add_tail(&obj->head, &dev_priv->display.global.obj_list);
92 }
93 
94 void intel_atomic_global_obj_cleanup(struct drm_i915_private *dev_priv)
95 {
96 	struct intel_global_obj *obj, *next;
97 
98 	list_for_each_entry_safe(obj, next, &dev_priv->display.global.obj_list, head) {
99 		list_del(&obj->head);
100 
101 		drm_WARN_ON(&dev_priv->drm, kref_read(&obj->state->ref) != 1);
102 		intel_atomic_global_state_put(obj->state);
103 	}
104 }
105 
106 static void assert_global_state_write_locked(struct drm_i915_private *dev_priv)
107 {
108 	struct intel_crtc *crtc;
109 
110 	for_each_intel_crtc(&dev_priv->drm, crtc)
111 		drm_modeset_lock_assert_held(&crtc->base.mutex);
112 }
113 
114 static bool modeset_lock_is_held(struct drm_modeset_acquire_ctx *ctx,
115 				 struct drm_modeset_lock *lock)
116 {
117 	struct drm_modeset_lock *l;
118 
119 	list_for_each_entry(l, &ctx->locked, head) {
120 		if (lock == l)
121 			return true;
122 	}
123 
124 	return false;
125 }
126 
127 static void assert_global_state_read_locked(struct intel_atomic_state *state)
128 {
129 	struct drm_modeset_acquire_ctx *ctx = state->base.acquire_ctx;
130 	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
131 	struct intel_crtc *crtc;
132 
133 	for_each_intel_crtc(&dev_priv->drm, crtc) {
134 		if (modeset_lock_is_held(ctx, &crtc->base.mutex))
135 			return;
136 	}
137 
138 	drm_WARN(&dev_priv->drm, 1, "Global state not read locked\n");
139 }
140 
141 struct intel_global_state *
142 intel_atomic_get_global_obj_state(struct intel_atomic_state *state,
143 				  struct intel_global_obj *obj)
144 {
145 	struct drm_i915_private *i915 = to_i915(state->base.dev);
146 	int index, num_objs, i;
147 	size_t size;
148 	struct __intel_global_objs_state *arr;
149 	struct intel_global_state *obj_state;
150 
151 	for (i = 0; i < state->num_global_objs; i++)
152 		if (obj == state->global_objs[i].ptr)
153 			return state->global_objs[i].state;
154 
155 	assert_global_state_read_locked(state);
156 
157 	num_objs = state->num_global_objs + 1;
158 	size = sizeof(*state->global_objs) * num_objs;
159 	arr = krealloc(state->global_objs, size, GFP_KERNEL);
160 	if (!arr)
161 		return ERR_PTR(-ENOMEM);
162 
163 	state->global_objs = arr;
164 	index = state->num_global_objs;
165 	memset(&state->global_objs[index], 0, sizeof(*state->global_objs));
166 
167 	obj_state = obj->funcs->atomic_duplicate_state(obj);
168 	if (!obj_state)
169 		return ERR_PTR(-ENOMEM);
170 
171 	obj_state->obj = obj;
172 	obj_state->changed = false;
173 	obj_state->serialized = false;
174 	obj_state->commit = NULL;
175 
176 	kref_init(&obj_state->ref);
177 
178 	state->global_objs[index].state = obj_state;
179 	state->global_objs[index].old_state =
180 		intel_atomic_global_state_get(obj->state);
181 	state->global_objs[index].new_state = obj_state;
182 	state->global_objs[index].ptr = obj;
183 	obj_state->state = state;
184 
185 	state->num_global_objs = num_objs;
186 
187 	drm_dbg_atomic(&i915->drm, "Added new global object %p state %p to %p\n",
188 		       obj, obj_state, state);
189 
190 	return obj_state;
191 }
192 
193 struct intel_global_state *
194 intel_atomic_get_old_global_obj_state(struct intel_atomic_state *state,
195 				      struct intel_global_obj *obj)
196 {
197 	int i;
198 
199 	for (i = 0; i < state->num_global_objs; i++)
200 		if (obj == state->global_objs[i].ptr)
201 			return state->global_objs[i].old_state;
202 
203 	return NULL;
204 }
205 
206 struct intel_global_state *
207 intel_atomic_get_new_global_obj_state(struct intel_atomic_state *state,
208 				      struct intel_global_obj *obj)
209 {
210 	int i;
211 
212 	for (i = 0; i < state->num_global_objs; i++)
213 		if (obj == state->global_objs[i].ptr)
214 			return state->global_objs[i].new_state;
215 
216 	return NULL;
217 }
218 
219 void intel_atomic_swap_global_state(struct intel_atomic_state *state)
220 {
221 	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
222 	struct intel_global_state *old_obj_state, *new_obj_state;
223 	struct intel_global_obj *obj;
224 	int i;
225 
226 	for_each_oldnew_global_obj_in_state(state, obj, old_obj_state,
227 					    new_obj_state, i) {
228 		drm_WARN_ON(&dev_priv->drm, obj->state != old_obj_state);
229 
230 		/*
231 		 * If the new state wasn't modified (and properly
232 		 * locked for write access) we throw it away.
233 		 */
234 		if (!new_obj_state->changed)
235 			continue;
236 
237 		assert_global_state_write_locked(dev_priv);
238 
239 		old_obj_state->state = state;
240 		new_obj_state->state = NULL;
241 
242 		state->global_objs[i].state = old_obj_state;
243 
244 		intel_atomic_global_state_put(obj->state);
245 		obj->state = intel_atomic_global_state_get(new_obj_state);
246 	}
247 }
248 
249 void intel_atomic_clear_global_state(struct intel_atomic_state *state)
250 {
251 	int i;
252 
253 	for (i = 0; i < state->num_global_objs; i++) {
254 		intel_atomic_global_state_put(state->global_objs[i].old_state);
255 		intel_atomic_global_state_put(state->global_objs[i].new_state);
256 
257 		state->global_objs[i].ptr = NULL;
258 		state->global_objs[i].state = NULL;
259 		state->global_objs[i].old_state = NULL;
260 		state->global_objs[i].new_state = NULL;
261 	}
262 	state->num_global_objs = 0;
263 }
264 
265 int intel_atomic_lock_global_state(struct intel_global_state *obj_state)
266 {
267 	struct intel_atomic_state *state = obj_state->state;
268 	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
269 	struct intel_crtc *crtc;
270 
271 	for_each_intel_crtc(&dev_priv->drm, crtc) {
272 		int ret;
273 
274 		ret = drm_modeset_lock(&crtc->base.mutex,
275 				       state->base.acquire_ctx);
276 		if (ret)
277 			return ret;
278 	}
279 
280 	obj_state->changed = true;
281 
282 	return 0;
283 }
284 
285 int intel_atomic_serialize_global_state(struct intel_global_state *obj_state)
286 {
287 	int ret;
288 
289 	ret = intel_atomic_lock_global_state(obj_state);
290 	if (ret)
291 		return ret;
292 
293 	obj_state->serialized = true;
294 
295 	return 0;
296 }
297 
298 bool
299 intel_atomic_global_state_is_serialized(struct intel_atomic_state *state)
300 {
301 	struct drm_i915_private *i915 = to_i915(state->base.dev);
302 	struct intel_crtc *crtc;
303 
304 	for_each_intel_crtc(&i915->drm, crtc)
305 		if (!intel_atomic_get_new_crtc_state(state, crtc))
306 			return false;
307 	return true;
308 }
309 
310 int
311 intel_atomic_global_state_setup_commit(struct intel_atomic_state *state)
312 {
313 	const struct intel_global_state *old_obj_state;
314 	struct intel_global_state *new_obj_state;
315 	struct intel_global_obj *obj;
316 	int i;
317 
318 	for_each_oldnew_global_obj_in_state(state, obj, old_obj_state,
319 					    new_obj_state, i) {
320 		struct intel_global_commit *commit = NULL;
321 
322 		if (new_obj_state->serialized) {
323 			/*
324 			 * New commit which is going to be completed
325 			 * after the hardware reprogramming is done.
326 			 */
327 			commit = commit_new();
328 			if (!commit)
329 				return -ENOMEM;
330 		} else if (new_obj_state->changed) {
331 			/*
332 			 * We're going to swap to this state, so carry the
333 			 * previous commit along, in case it's not yet done.
334 			 */
335 			commit = commit_get(old_obj_state->commit);
336 		}
337 
338 		new_obj_state->commit = commit;
339 	}
340 
341 	return 0;
342 }
343 
344 int
345 intel_atomic_global_state_wait_for_dependencies(struct intel_atomic_state *state)
346 {
347 	struct drm_i915_private *i915 = to_i915(state->base.dev);
348 	const struct intel_global_state *old_obj_state;
349 	struct intel_global_obj *obj;
350 	int i;
351 
352 	for_each_old_global_obj_in_state(state, obj, old_obj_state, i) {
353 		struct intel_global_commit *commit = old_obj_state->commit;
354 		long ret;
355 
356 		if (!commit)
357 			continue;
358 
359 		ret = wait_for_completion_timeout(&commit->done, 10 * HZ);
360 		if (ret == 0) {
361 			drm_err(&i915->drm, "global state timed out\n");
362 			return -ETIMEDOUT;
363 		}
364 	}
365 
366 	return 0;
367 }
368 
369 void
370 intel_atomic_global_state_commit_done(struct intel_atomic_state *state)
371 {
372 	const struct intel_global_state *new_obj_state;
373 	struct intel_global_obj *obj;
374 	int i;
375 
376 	for_each_new_global_obj_in_state(state, obj, new_obj_state, i) {
377 		struct intel_global_commit *commit = new_obj_state->commit;
378 
379 		if (!new_obj_state->serialized)
380 			continue;
381 
382 		complete_all(&commit->done);
383 	}
384 }
385