1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Tegra host1x Syncpoints
4  *
5  * Copyright (c) 2010-2015, NVIDIA Corporation.
6  */
7 
8 #include <linux/module.h>
9 #include <linux/device.h>
10 #include <linux/dma-fence.h>
11 #include <linux/slab.h>
12 
13 #include <trace/events/host1x.h>
14 
15 #include "syncpt.h"
16 #include "dev.h"
17 #include "intr.h"
18 #include "debug.h"
19 
20 #define SYNCPT_CHECK_PERIOD (2 * HZ)
21 #define MAX_STUCK_CHECK_COUNT 15
22 
23 static struct host1x_syncpt_base *
host1x_syncpt_base_request(struct host1x * host)24 host1x_syncpt_base_request(struct host1x *host)
25 {
26 	struct host1x_syncpt_base *bases = host->bases;
27 	unsigned int i;
28 
29 	for (i = 0; i < host->info->nb_bases; i++)
30 		if (!bases[i].requested)
31 			break;
32 
33 	if (i >= host->info->nb_bases)
34 		return NULL;
35 
36 	bases[i].requested = true;
37 	return &bases[i];
38 }
39 
host1x_syncpt_base_free(struct host1x_syncpt_base * base)40 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
41 {
42 	if (base)
43 		base->requested = false;
44 }
45 
46 /**
47  * host1x_syncpt_alloc() - allocate a syncpoint
48  * @host: host1x device data
49  * @flags: bitfield of HOST1X_SYNCPT_* flags
50  * @name: name for the syncpoint for use in debug prints
51  *
52  * Allocates a hardware syncpoint for the caller's use. The caller then has
53  * the sole authority to mutate the syncpoint's value until it is freed again.
54  *
55  * If no free syncpoints are available, or a NULL name was specified, returns
56  * NULL.
57  */
host1x_syncpt_alloc(struct host1x * host,unsigned long flags,const char * name)58 struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
59 					  unsigned long flags,
60 					  const char *name)
61 {
62 	struct host1x_syncpt *sp = host->syncpt;
63 	char *full_name;
64 	unsigned int i;
65 
66 	if (!name)
67 		return NULL;
68 
69 	mutex_lock(&host->syncpt_mutex);
70 
71 	for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++)
72 		;
73 
74 	if (i >= host->info->nb_pts)
75 		goto unlock;
76 
77 	if (flags & HOST1X_SYNCPT_HAS_BASE) {
78 		sp->base = host1x_syncpt_base_request(host);
79 		if (!sp->base)
80 			goto unlock;
81 	}
82 
83 	full_name = kasprintf(GFP_KERNEL, "%u-%s", sp->id, name);
84 	if (!full_name)
85 		goto free_base;
86 
87 	sp->name = full_name;
88 
89 	if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
90 		sp->client_managed = true;
91 	else
92 		sp->client_managed = false;
93 
94 	kref_init(&sp->ref);
95 
96 	mutex_unlock(&host->syncpt_mutex);
97 	return sp;
98 
99 free_base:
100 	host1x_syncpt_base_free(sp->base);
101 	sp->base = NULL;
102 unlock:
103 	mutex_unlock(&host->syncpt_mutex);
104 	return NULL;
105 }
106 EXPORT_SYMBOL(host1x_syncpt_alloc);
107 
108 /**
109  * host1x_syncpt_id() - retrieve syncpoint ID
110  * @sp: host1x syncpoint
111  *
112  * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
113  * often used as a value to program into registers that control how hardware
114  * blocks interact with syncpoints.
115  */
host1x_syncpt_id(struct host1x_syncpt * sp)116 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
117 {
118 	return sp->id;
119 }
120 EXPORT_SYMBOL(host1x_syncpt_id);
121 
122 /**
123  * host1x_syncpt_incr_max() - update the value sent to hardware
124  * @sp: host1x syncpoint
125  * @incrs: number of increments
126  */
host1x_syncpt_incr_max(struct host1x_syncpt * sp,u32 incrs)127 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
128 {
129 	return (u32)atomic_add_return(incrs, &sp->max_val);
130 }
131 EXPORT_SYMBOL(host1x_syncpt_incr_max);
132 
133  /*
134  * Write cached syncpoint and waitbase values to hardware.
135  */
host1x_syncpt_restore(struct host1x * host)136 void host1x_syncpt_restore(struct host1x *host)
137 {
138 	struct host1x_syncpt *sp_base = host->syncpt;
139 	unsigned int i;
140 
141 	for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
142 		/*
143 		 * Unassign syncpt from channels for purposes of Tegra186
144 		 * syncpoint protection. This prevents any channel from
145 		 * accessing it until it is reassigned.
146 		 */
147 		host1x_hw_syncpt_assign_to_channel(host, sp_base + i, NULL);
148 		host1x_hw_syncpt_restore(host, sp_base + i);
149 	}
150 
151 	for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
152 		host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
153 
154 	host1x_hw_syncpt_enable_protection(host);
155 
156 	wmb();
157 }
158 
159 /*
160  * Update the cached syncpoint and waitbase values by reading them
161  * from the registers.
162   */
host1x_syncpt_save(struct host1x * host)163 void host1x_syncpt_save(struct host1x *host)
164 {
165 	struct host1x_syncpt *sp_base = host->syncpt;
166 	unsigned int i;
167 
168 	for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
169 		if (host1x_syncpt_client_managed(sp_base + i))
170 			host1x_hw_syncpt_load(host, sp_base + i);
171 		else
172 			WARN_ON(!host1x_syncpt_idle(sp_base + i));
173 	}
174 
175 	for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
176 		host1x_hw_syncpt_load_wait_base(host, sp_base + i);
177 }
178 
179 /*
180  * Updates the cached syncpoint value by reading a new value from the hardware
181  * register
182  */
host1x_syncpt_load(struct host1x_syncpt * sp)183 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
184 {
185 	u32 val;
186 
187 	val = host1x_hw_syncpt_load(sp->host, sp);
188 	trace_host1x_syncpt_load_min(sp->id, val);
189 
190 	return val;
191 }
192 
193 /*
194  * Get the current syncpoint base
195  */
host1x_syncpt_load_wait_base(struct host1x_syncpt * sp)196 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
197 {
198 	host1x_hw_syncpt_load_wait_base(sp->host, sp);
199 
200 	return sp->base_val;
201 }
202 
203 /**
204  * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
205  * @sp: host1x syncpoint
206  */
host1x_syncpt_incr(struct host1x_syncpt * sp)207 int host1x_syncpt_incr(struct host1x_syncpt *sp)
208 {
209 	return host1x_hw_syncpt_cpu_incr(sp->host, sp);
210 }
211 EXPORT_SYMBOL(host1x_syncpt_incr);
212 
213 /**
214  * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
215  * @sp: host1x syncpoint
216  * @thresh: threshold
217  * @timeout: maximum time to wait for the syncpoint to reach the given value
218  * @value: return location for the syncpoint value
219  */
host1x_syncpt_wait(struct host1x_syncpt * sp,u32 thresh,long timeout,u32 * value)220 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
221 		       u32 *value)
222 {
223 	struct dma_fence *fence;
224 	long wait_err;
225 
226 	host1x_hw_syncpt_load(sp->host, sp);
227 
228 	if (value)
229 		*value = host1x_syncpt_load(sp);
230 
231 	if (host1x_syncpt_is_expired(sp, thresh))
232 		return 0;
233 
234 	if (timeout < 0)
235 		timeout = LONG_MAX;
236 	else if (timeout == 0)
237 		return -EAGAIN;
238 
239 	fence = host1x_fence_create(sp, thresh, false);
240 	if (IS_ERR(fence))
241 		return PTR_ERR(fence);
242 
243 	wait_err = dma_fence_wait_timeout(fence, true, timeout);
244 	if (wait_err == 0)
245 		host1x_fence_cancel(fence);
246 	dma_fence_put(fence);
247 
248 	if (value)
249 		*value = host1x_syncpt_load(sp);
250 
251 	/*
252 	 * Don't rely on dma_fence_wait_timeout return value,
253 	 * since it returns zero both on timeout and if the
254 	 * wait completed with 0 jiffies left.
255 	 */
256 	host1x_hw_syncpt_load(sp->host, sp);
257 	if (wait_err == 0 && !host1x_syncpt_is_expired(sp, thresh))
258 		return -EAGAIN;
259 	else if (wait_err < 0)
260 		return wait_err;
261 	else
262 		return 0;
263 }
264 EXPORT_SYMBOL(host1x_syncpt_wait);
265 
266 /*
267  * Returns true if syncpoint is expired, false if we may need to wait
268  */
host1x_syncpt_is_expired(struct host1x_syncpt * sp,u32 thresh)269 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
270 {
271 	u32 current_val;
272 
273 	smp_rmb();
274 
275 	current_val = (u32)atomic_read(&sp->min_val);
276 
277 	return ((current_val - thresh) & 0x80000000U) == 0U;
278 }
279 
host1x_syncpt_init(struct host1x * host)280 int host1x_syncpt_init(struct host1x *host)
281 {
282 	struct host1x_syncpt_base *bases;
283 	struct host1x_syncpt *syncpt;
284 	unsigned int i;
285 
286 	syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
287 			      GFP_KERNEL);
288 	if (!syncpt)
289 		return -ENOMEM;
290 
291 	bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
292 			     GFP_KERNEL);
293 	if (!bases)
294 		return -ENOMEM;
295 
296 	for (i = 0; i < host->info->nb_pts; i++) {
297 		syncpt[i].id = i;
298 		syncpt[i].host = host;
299 	}
300 
301 	for (i = 0; i < host->info->nb_bases; i++)
302 		bases[i].id = i;
303 
304 	mutex_init(&host->syncpt_mutex);
305 	host->syncpt = syncpt;
306 	host->bases = bases;
307 
308 	/* Allocate sync point to use for clearing waits for expired fences */
309 	host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
310 	if (!host->nop_sp)
311 		return -ENOMEM;
312 
313 	if (host->info->reserve_vblank_syncpts) {
314 		kref_init(&host->syncpt[26].ref);
315 		kref_init(&host->syncpt[27].ref);
316 	}
317 
318 	return 0;
319 }
320 
321 /**
322  * host1x_syncpt_request() - request a syncpoint
323  * @client: client requesting the syncpoint
324  * @flags: flags
325  *
326  * host1x client drivers can use this function to allocate a syncpoint for
327  * subsequent use. A syncpoint returned by this function will be reserved for
328  * use by the client exclusively. When no longer using a syncpoint, a host1x
329  * client driver needs to release it using host1x_syncpt_put().
330  */
host1x_syncpt_request(struct host1x_client * client,unsigned long flags)331 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
332 					    unsigned long flags)
333 {
334 	struct host1x *host = dev_get_drvdata(client->host->parent);
335 
336 	return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
337 }
338 EXPORT_SYMBOL(host1x_syncpt_request);
339 
syncpt_release(struct kref * ref)340 static void syncpt_release(struct kref *ref)
341 {
342 	struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
343 
344 	atomic_set(&sp->max_val, host1x_syncpt_read(sp));
345 
346 	sp->locked = false;
347 
348 	mutex_lock(&sp->host->syncpt_mutex);
349 
350 	host1x_syncpt_base_free(sp->base);
351 	kfree(sp->name);
352 	sp->base = NULL;
353 	sp->name = NULL;
354 	sp->client_managed = false;
355 
356 	mutex_unlock(&sp->host->syncpt_mutex);
357 }
358 
359 /**
360  * host1x_syncpt_put() - free a requested syncpoint
361  * @sp: host1x syncpoint
362  *
363  * Release a syncpoint previously allocated using host1x_syncpt_request(). A
364  * host1x client driver should call this when the syncpoint is no longer in
365  * use.
366  */
host1x_syncpt_put(struct host1x_syncpt * sp)367 void host1x_syncpt_put(struct host1x_syncpt *sp)
368 {
369 	if (!sp)
370 		return;
371 
372 	kref_put(&sp->ref, syncpt_release);
373 }
374 EXPORT_SYMBOL(host1x_syncpt_put);
375 
host1x_syncpt_deinit(struct host1x * host)376 void host1x_syncpt_deinit(struct host1x *host)
377 {
378 	struct host1x_syncpt *sp = host->syncpt;
379 	unsigned int i;
380 
381 	for (i = 0; i < host->info->nb_pts; i++, sp++)
382 		kfree(sp->name);
383 }
384 
385 /**
386  * host1x_syncpt_read_max() - read maximum syncpoint value
387  * @sp: host1x syncpoint
388  *
389  * The maximum syncpoint value indicates how many operations there are in
390  * queue, either in channel or in a software thread.
391  */
host1x_syncpt_read_max(struct host1x_syncpt * sp)392 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
393 {
394 	smp_rmb();
395 
396 	return (u32)atomic_read(&sp->max_val);
397 }
398 EXPORT_SYMBOL(host1x_syncpt_read_max);
399 
400 /**
401  * host1x_syncpt_read_min() - read minimum syncpoint value
402  * @sp: host1x syncpoint
403  *
404  * The minimum syncpoint value is a shadow of the current sync point value in
405  * hardware.
406  */
host1x_syncpt_read_min(struct host1x_syncpt * sp)407 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
408 {
409 	smp_rmb();
410 
411 	return (u32)atomic_read(&sp->min_val);
412 }
413 EXPORT_SYMBOL(host1x_syncpt_read_min);
414 
415 /**
416  * host1x_syncpt_read() - read the current syncpoint value
417  * @sp: host1x syncpoint
418  */
host1x_syncpt_read(struct host1x_syncpt * sp)419 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
420 {
421 	return host1x_syncpt_load(sp);
422 }
423 EXPORT_SYMBOL(host1x_syncpt_read);
424 
host1x_syncpt_nb_pts(struct host1x * host)425 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
426 {
427 	return host->info->nb_pts;
428 }
429 
host1x_syncpt_nb_bases(struct host1x * host)430 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
431 {
432 	return host->info->nb_bases;
433 }
434 
host1x_syncpt_nb_mlocks(struct host1x * host)435 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
436 {
437 	return host->info->nb_mlocks;
438 }
439 
440 /**
441  * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
442  * @host: host1x controller
443  * @id: syncpoint ID
444  */
host1x_syncpt_get_by_id(struct host1x * host,unsigned int id)445 struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
446 					      unsigned int id)
447 {
448 	if (id >= host->info->nb_pts)
449 		return NULL;
450 
451 	if (kref_get_unless_zero(&host->syncpt[id].ref))
452 		return &host->syncpt[id];
453 	else
454 		return NULL;
455 }
456 EXPORT_SYMBOL(host1x_syncpt_get_by_id);
457 
458 /**
459  * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
460  * 	increase the refcount.
461  * @host: host1x controller
462  * @id: syncpoint ID
463  */
host1x_syncpt_get_by_id_noref(struct host1x * host,unsigned int id)464 struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
465 						    unsigned int id)
466 {
467 	if (id >= host->info->nb_pts)
468 		return NULL;
469 
470 	return &host->syncpt[id];
471 }
472 EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
473 
474 /**
475  * host1x_syncpt_get() - increment syncpoint refcount
476  * @sp: syncpoint
477  */
host1x_syncpt_get(struct host1x_syncpt * sp)478 struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
479 {
480 	kref_get(&sp->ref);
481 
482 	return sp;
483 }
484 EXPORT_SYMBOL(host1x_syncpt_get);
485 
486 /**
487  * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
488  * @sp: host1x syncpoint
489  */
host1x_syncpt_get_base(struct host1x_syncpt * sp)490 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
491 {
492 	return sp ? sp->base : NULL;
493 }
494 EXPORT_SYMBOL(host1x_syncpt_get_base);
495 
496 /**
497  * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
498  * @base: host1x syncpoint wait base
499  */
host1x_syncpt_base_id(struct host1x_syncpt_base * base)500 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
501 {
502 	return base->id;
503 }
504 EXPORT_SYMBOL(host1x_syncpt_base_id);
505 
do_nothing(struct kref * ref)506 static void do_nothing(struct kref *ref)
507 {
508 }
509 
510 /**
511  * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
512  *   available for allocation
513  *
514  * @client: host1x bus client
515  * @syncpt_id: syncpoint ID to make available
516  *
517  * Makes VBLANK<i> syncpoint available for allocatation if it was
518  * reserved at initialization time. This should be called by the display
519  * driver after it has ensured that any VBLANK increment programming configured
520  * by the boot chain has been disabled.
521  */
host1x_syncpt_release_vblank_reservation(struct host1x_client * client,u32 syncpt_id)522 void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
523 					      u32 syncpt_id)
524 {
525 	struct host1x *host = dev_get_drvdata(client->host->parent);
526 
527 	if (!host->info->reserve_vblank_syncpts)
528 		return;
529 
530 	kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
531 }
532 EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);
533