1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * fsl-mc object allocator driver
4  *
5  * Copyright (C) 2013-2016 Freescale Semiconductor, Inc.
6  *
7  */
8 
9 #include <linux/module.h>
10 #include <linux/msi.h>
11 #include <linux/fsl/mc.h>
12 
13 #include "fsl-mc-private.h"
14 
15 static bool __must_check fsl_mc_is_allocatable(struct fsl_mc_device *mc_dev)
16 {
17 	return is_fsl_mc_bus_dpbp(mc_dev) ||
18 	       is_fsl_mc_bus_dpmcp(mc_dev) ||
19 	       is_fsl_mc_bus_dpcon(mc_dev);
20 }
21 
22 /**
23  * fsl_mc_resource_pool_add_device - add allocatable object to a resource
24  * pool of a given fsl-mc bus
25  *
26  * @mc_bus: pointer to the fsl-mc bus
27  * @pool_type: pool type
28  * @mc_dev: pointer to allocatable fsl-mc device
29  */
30 static int __must_check fsl_mc_resource_pool_add_device(struct fsl_mc_bus
31 								*mc_bus,
32 							enum fsl_mc_pool_type
33 								pool_type,
34 							struct fsl_mc_device
35 								*mc_dev)
36 {
37 	struct fsl_mc_resource_pool *res_pool;
38 	struct fsl_mc_resource *resource;
39 	struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
40 	int error = -EINVAL;
41 
42 	if (pool_type < 0 || pool_type >= FSL_MC_NUM_POOL_TYPES)
43 		goto out;
44 	if (!fsl_mc_is_allocatable(mc_dev))
45 		goto out;
46 	if (mc_dev->resource)
47 		goto out;
48 
49 	res_pool = &mc_bus->resource_pools[pool_type];
50 	if (res_pool->type != pool_type)
51 		goto out;
52 	if (res_pool->mc_bus != mc_bus)
53 		goto out;
54 
55 	mutex_lock(&res_pool->mutex);
56 
57 	if (res_pool->max_count < 0)
58 		goto out_unlock;
59 	if (res_pool->free_count < 0 ||
60 	    res_pool->free_count > res_pool->max_count)
61 		goto out_unlock;
62 
63 	resource = devm_kzalloc(&mc_bus_dev->dev, sizeof(*resource),
64 				GFP_KERNEL);
65 	if (!resource) {
66 		error = -ENOMEM;
67 		dev_err(&mc_bus_dev->dev,
68 			"Failed to allocate memory for fsl_mc_resource\n");
69 		goto out_unlock;
70 	}
71 
72 	resource->type = pool_type;
73 	resource->id = mc_dev->obj_desc.id;
74 	resource->data = mc_dev;
75 	resource->parent_pool = res_pool;
76 	INIT_LIST_HEAD(&resource->node);
77 	list_add_tail(&resource->node, &res_pool->free_list);
78 	mc_dev->resource = resource;
79 	res_pool->free_count++;
80 	res_pool->max_count++;
81 	error = 0;
82 out_unlock:
83 	mutex_unlock(&res_pool->mutex);
84 out:
85 	return error;
86 }
87 
88 /**
89  * fsl_mc_resource_pool_remove_device - remove an allocatable device from a
90  * resource pool
91  *
92  * @mc_dev: pointer to allocatable fsl-mc device
93  *
94  * It permanently removes an allocatable fsl-mc device from the resource
95  * pool. It's an error if the device is in use.
96  */
97 static int __must_check fsl_mc_resource_pool_remove_device(struct fsl_mc_device
98 								   *mc_dev)
99 {
100 	struct fsl_mc_device *mc_bus_dev;
101 	struct fsl_mc_bus *mc_bus;
102 	struct fsl_mc_resource_pool *res_pool;
103 	struct fsl_mc_resource *resource;
104 	int error = -EINVAL;
105 
106 	if (!fsl_mc_is_allocatable(mc_dev))
107 		goto out;
108 
109 	resource = mc_dev->resource;
110 	if (!resource || resource->data != mc_dev)
111 		goto out;
112 
113 	mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
114 	mc_bus = to_fsl_mc_bus(mc_bus_dev);
115 	res_pool = resource->parent_pool;
116 	if (res_pool != &mc_bus->resource_pools[resource->type])
117 		goto out;
118 
119 	mutex_lock(&res_pool->mutex);
120 
121 	if (res_pool->max_count <= 0)
122 		goto out_unlock;
123 	if (res_pool->free_count <= 0 ||
124 	    res_pool->free_count > res_pool->max_count)
125 		goto out_unlock;
126 
127 	/*
128 	 * If the device is currently allocated, its resource is not
129 	 * in the free list and thus, the device cannot be removed.
130 	 */
131 	if (list_empty(&resource->node)) {
132 		error = -EBUSY;
133 		dev_err(&mc_bus_dev->dev,
134 			"Device %s cannot be removed from resource pool\n",
135 			dev_name(&mc_dev->dev));
136 		goto out_unlock;
137 	}
138 
139 	list_del_init(&resource->node);
140 	res_pool->free_count--;
141 	res_pool->max_count--;
142 
143 	devm_kfree(&mc_bus_dev->dev, resource);
144 	mc_dev->resource = NULL;
145 	error = 0;
146 out_unlock:
147 	mutex_unlock(&res_pool->mutex);
148 out:
149 	return error;
150 }
151 
152 static const char *const fsl_mc_pool_type_strings[] = {
153 	[FSL_MC_POOL_DPMCP] = "dpmcp",
154 	[FSL_MC_POOL_DPBP] = "dpbp",
155 	[FSL_MC_POOL_DPCON] = "dpcon",
156 	[FSL_MC_POOL_IRQ] = "irq",
157 };
158 
159 static int __must_check object_type_to_pool_type(const char *object_type,
160 						 enum fsl_mc_pool_type
161 								*pool_type)
162 {
163 	unsigned int i;
164 
165 	for (i = 0; i < ARRAY_SIZE(fsl_mc_pool_type_strings); i++) {
166 		if (strcmp(object_type, fsl_mc_pool_type_strings[i]) == 0) {
167 			*pool_type = i;
168 			return 0;
169 		}
170 	}
171 
172 	return -EINVAL;
173 }
174 
175 int __must_check fsl_mc_resource_allocate(struct fsl_mc_bus *mc_bus,
176 					  enum fsl_mc_pool_type pool_type,
177 					  struct fsl_mc_resource **new_resource)
178 {
179 	struct fsl_mc_resource_pool *res_pool;
180 	struct fsl_mc_resource *resource;
181 	struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
182 	int error = -EINVAL;
183 
184 	BUILD_BUG_ON(ARRAY_SIZE(fsl_mc_pool_type_strings) !=
185 		     FSL_MC_NUM_POOL_TYPES);
186 
187 	*new_resource = NULL;
188 	if (pool_type < 0 || pool_type >= FSL_MC_NUM_POOL_TYPES)
189 		goto out;
190 
191 	res_pool = &mc_bus->resource_pools[pool_type];
192 	if (res_pool->mc_bus != mc_bus)
193 		goto out;
194 
195 	mutex_lock(&res_pool->mutex);
196 	resource = list_first_entry_or_null(&res_pool->free_list,
197 					    struct fsl_mc_resource, node);
198 
199 	if (!resource) {
200 		error = -ENXIO;
201 		dev_err(&mc_bus_dev->dev,
202 			"No more resources of type %s left\n",
203 			fsl_mc_pool_type_strings[pool_type]);
204 		goto out_unlock;
205 	}
206 
207 	if (resource->type != pool_type)
208 		goto out_unlock;
209 	if (resource->parent_pool != res_pool)
210 		goto out_unlock;
211 	if (res_pool->free_count <= 0 ||
212 	    res_pool->free_count > res_pool->max_count)
213 		goto out_unlock;
214 
215 	list_del_init(&resource->node);
216 
217 	res_pool->free_count--;
218 	error = 0;
219 out_unlock:
220 	mutex_unlock(&res_pool->mutex);
221 	*new_resource = resource;
222 out:
223 	return error;
224 }
225 EXPORT_SYMBOL_GPL(fsl_mc_resource_allocate);
226 
227 void fsl_mc_resource_free(struct fsl_mc_resource *resource)
228 {
229 	struct fsl_mc_resource_pool *res_pool;
230 
231 	res_pool = resource->parent_pool;
232 	if (resource->type != res_pool->type)
233 		return;
234 
235 	mutex_lock(&res_pool->mutex);
236 	if (res_pool->free_count < 0 ||
237 	    res_pool->free_count >= res_pool->max_count)
238 		goto out_unlock;
239 
240 	if (!list_empty(&resource->node))
241 		goto out_unlock;
242 
243 	list_add_tail(&resource->node, &res_pool->free_list);
244 	res_pool->free_count++;
245 out_unlock:
246 	mutex_unlock(&res_pool->mutex);
247 }
248 EXPORT_SYMBOL_GPL(fsl_mc_resource_free);
249 
250 /**
251  * fsl_mc_object_allocate - Allocates an fsl-mc object of the given
252  * pool type from a given fsl-mc bus instance
253  *
254  * @mc_dev: fsl-mc device which is used in conjunction with the
255  * allocated object
256  * @pool_type: pool type
257  * @new_mc_dev: pointer to area where the pointer to the allocated device
258  * is to be returned
259  *
260  * Allocatable objects are always used in conjunction with some functional
261  * device.  This function allocates an object of the specified type from
262  * the DPRC containing the functional device.
263  *
264  * NOTE: pool_type must be different from FSL_MC_POOL_MCP, since MC
265  * portals are allocated using fsl_mc_portal_allocate(), instead of
266  * this function.
267  */
268 int __must_check fsl_mc_object_allocate(struct fsl_mc_device *mc_dev,
269 					enum fsl_mc_pool_type pool_type,
270 					struct fsl_mc_device **new_mc_adev)
271 {
272 	struct fsl_mc_device *mc_bus_dev;
273 	struct fsl_mc_bus *mc_bus;
274 	struct fsl_mc_device *mc_adev;
275 	int error = -EINVAL;
276 	struct fsl_mc_resource *resource = NULL;
277 
278 	*new_mc_adev = NULL;
279 	if (mc_dev->flags & FSL_MC_IS_DPRC)
280 		goto error;
281 
282 	if (!dev_is_fsl_mc(mc_dev->dev.parent))
283 		goto error;
284 
285 	if (pool_type == FSL_MC_POOL_DPMCP)
286 		goto error;
287 
288 	mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
289 	mc_bus = to_fsl_mc_bus(mc_bus_dev);
290 	error = fsl_mc_resource_allocate(mc_bus, pool_type, &resource);
291 	if (error < 0)
292 		goto error;
293 
294 	mc_adev = resource->data;
295 	if (!mc_adev)
296 		goto error;
297 
298 	*new_mc_adev = mc_adev;
299 	return 0;
300 error:
301 	if (resource)
302 		fsl_mc_resource_free(resource);
303 
304 	return error;
305 }
306 EXPORT_SYMBOL_GPL(fsl_mc_object_allocate);
307 
308 /**
309  * fsl_mc_object_free - Returns an fsl-mc object to the resource
310  * pool where it came from.
311  * @mc_adev: Pointer to the fsl-mc device
312  */
313 void fsl_mc_object_free(struct fsl_mc_device *mc_adev)
314 {
315 	struct fsl_mc_resource *resource;
316 
317 	resource = mc_adev->resource;
318 	if (resource->type == FSL_MC_POOL_DPMCP)
319 		return;
320 	if (resource->data != mc_adev)
321 		return;
322 
323 	fsl_mc_resource_free(resource);
324 }
325 EXPORT_SYMBOL_GPL(fsl_mc_object_free);
326 
327 /*
328  * A DPRC and the devices in the DPRC all share the same GIC-ITS device
329  * ID.  A block of IRQs is pre-allocated and maintained in a pool
330  * from which devices can allocate them when needed.
331  */
332 
333 /*
334  * Initialize the interrupt pool associated with an fsl-mc bus.
335  * It allocates a block of IRQs from the GIC-ITS.
336  */
337 int fsl_mc_populate_irq_pool(struct fsl_mc_bus *mc_bus,
338 			     unsigned int irq_count)
339 {
340 	unsigned int i;
341 	struct msi_desc *msi_desc;
342 	struct fsl_mc_device_irq *irq_resources;
343 	struct fsl_mc_device_irq *mc_dev_irq;
344 	int error;
345 	struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
346 	struct fsl_mc_resource_pool *res_pool =
347 			&mc_bus->resource_pools[FSL_MC_POOL_IRQ];
348 
349 	if (irq_count == 0 ||
350 	    irq_count > FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS)
351 		return -EINVAL;
352 
353 	error = fsl_mc_msi_domain_alloc_irqs(&mc_bus_dev->dev, irq_count);
354 	if (error < 0)
355 		return error;
356 
357 	irq_resources = devm_kzalloc(&mc_bus_dev->dev,
358 				     sizeof(*irq_resources) * irq_count,
359 				     GFP_KERNEL);
360 	if (!irq_resources) {
361 		error = -ENOMEM;
362 		goto cleanup_msi_irqs;
363 	}
364 
365 	for (i = 0; i < irq_count; i++) {
366 		mc_dev_irq = &irq_resources[i];
367 
368 		/*
369 		 * NOTE: This mc_dev_irq's MSI addr/value pair will be set
370 		 * by the fsl_mc_msi_write_msg() callback
371 		 */
372 		mc_dev_irq->resource.type = res_pool->type;
373 		mc_dev_irq->resource.data = mc_dev_irq;
374 		mc_dev_irq->resource.parent_pool = res_pool;
375 		INIT_LIST_HEAD(&mc_dev_irq->resource.node);
376 		list_add_tail(&mc_dev_irq->resource.node, &res_pool->free_list);
377 	}
378 
379 	for_each_msi_entry(msi_desc, &mc_bus_dev->dev) {
380 		mc_dev_irq = &irq_resources[msi_desc->fsl_mc.msi_index];
381 		mc_dev_irq->msi_desc = msi_desc;
382 		mc_dev_irq->resource.id = msi_desc->irq;
383 	}
384 
385 	res_pool->max_count = irq_count;
386 	res_pool->free_count = irq_count;
387 	mc_bus->irq_resources = irq_resources;
388 	return 0;
389 
390 cleanup_msi_irqs:
391 	fsl_mc_msi_domain_free_irqs(&mc_bus_dev->dev);
392 	return error;
393 }
394 EXPORT_SYMBOL_GPL(fsl_mc_populate_irq_pool);
395 
396 /**
397  * Teardown the interrupt pool associated with an fsl-mc bus.
398  * It frees the IRQs that were allocated to the pool, back to the GIC-ITS.
399  */
400 void fsl_mc_cleanup_irq_pool(struct fsl_mc_bus *mc_bus)
401 {
402 	struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
403 	struct fsl_mc_resource_pool *res_pool =
404 			&mc_bus->resource_pools[FSL_MC_POOL_IRQ];
405 
406 	if (!mc_bus->irq_resources)
407 		return;
408 
409 	if (res_pool->max_count == 0)
410 		return;
411 
412 	if (res_pool->free_count != res_pool->max_count)
413 		return;
414 
415 	INIT_LIST_HEAD(&res_pool->free_list);
416 	res_pool->max_count = 0;
417 	res_pool->free_count = 0;
418 	mc_bus->irq_resources = NULL;
419 	fsl_mc_msi_domain_free_irqs(&mc_bus_dev->dev);
420 }
421 EXPORT_SYMBOL_GPL(fsl_mc_cleanup_irq_pool);
422 
423 /**
424  * Allocate the IRQs required by a given fsl-mc device.
425  */
426 int __must_check fsl_mc_allocate_irqs(struct fsl_mc_device *mc_dev)
427 {
428 	int i;
429 	int irq_count;
430 	int res_allocated_count = 0;
431 	int error = -EINVAL;
432 	struct fsl_mc_device_irq **irqs = NULL;
433 	struct fsl_mc_bus *mc_bus;
434 	struct fsl_mc_resource_pool *res_pool;
435 
436 	if (mc_dev->irqs)
437 		return -EINVAL;
438 
439 	irq_count = mc_dev->obj_desc.irq_count;
440 	if (irq_count == 0)
441 		return -EINVAL;
442 
443 	if (is_fsl_mc_bus_dprc(mc_dev))
444 		mc_bus = to_fsl_mc_bus(mc_dev);
445 	else
446 		mc_bus = to_fsl_mc_bus(to_fsl_mc_device(mc_dev->dev.parent));
447 
448 	if (!mc_bus->irq_resources)
449 		return -EINVAL;
450 
451 	res_pool = &mc_bus->resource_pools[FSL_MC_POOL_IRQ];
452 	if (res_pool->free_count < irq_count) {
453 		dev_err(&mc_dev->dev,
454 			"Not able to allocate %u irqs for device\n", irq_count);
455 		return -ENOSPC;
456 	}
457 
458 	irqs = devm_kzalloc(&mc_dev->dev, irq_count * sizeof(irqs[0]),
459 			    GFP_KERNEL);
460 	if (!irqs)
461 		return -ENOMEM;
462 
463 	for (i = 0; i < irq_count; i++) {
464 		struct fsl_mc_resource *resource;
465 
466 		error = fsl_mc_resource_allocate(mc_bus, FSL_MC_POOL_IRQ,
467 						 &resource);
468 		if (error < 0)
469 			goto error_resource_alloc;
470 
471 		irqs[i] = to_fsl_mc_irq(resource);
472 		res_allocated_count++;
473 
474 		irqs[i]->mc_dev = mc_dev;
475 		irqs[i]->dev_irq_index = i;
476 	}
477 
478 	mc_dev->irqs = irqs;
479 	return 0;
480 
481 error_resource_alloc:
482 	for (i = 0; i < res_allocated_count; i++) {
483 		irqs[i]->mc_dev = NULL;
484 		fsl_mc_resource_free(&irqs[i]->resource);
485 	}
486 
487 	return error;
488 }
489 EXPORT_SYMBOL_GPL(fsl_mc_allocate_irqs);
490 
491 /*
492  * Frees the IRQs that were allocated for an fsl-mc device.
493  */
494 void fsl_mc_free_irqs(struct fsl_mc_device *mc_dev)
495 {
496 	int i;
497 	int irq_count;
498 	struct fsl_mc_bus *mc_bus;
499 	struct fsl_mc_device_irq **irqs = mc_dev->irqs;
500 
501 	if (!irqs)
502 		return;
503 
504 	irq_count = mc_dev->obj_desc.irq_count;
505 
506 	if (is_fsl_mc_bus_dprc(mc_dev))
507 		mc_bus = to_fsl_mc_bus(mc_dev);
508 	else
509 		mc_bus = to_fsl_mc_bus(to_fsl_mc_device(mc_dev->dev.parent));
510 
511 	if (!mc_bus->irq_resources)
512 		return;
513 
514 	for (i = 0; i < irq_count; i++) {
515 		irqs[i]->mc_dev = NULL;
516 		fsl_mc_resource_free(&irqs[i]->resource);
517 	}
518 
519 	mc_dev->irqs = NULL;
520 }
521 EXPORT_SYMBOL_GPL(fsl_mc_free_irqs);
522 
523 void fsl_mc_init_all_resource_pools(struct fsl_mc_device *mc_bus_dev)
524 {
525 	int pool_type;
526 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
527 
528 	for (pool_type = 0; pool_type < FSL_MC_NUM_POOL_TYPES; pool_type++) {
529 		struct fsl_mc_resource_pool *res_pool =
530 		    &mc_bus->resource_pools[pool_type];
531 
532 		res_pool->type = pool_type;
533 		res_pool->max_count = 0;
534 		res_pool->free_count = 0;
535 		res_pool->mc_bus = mc_bus;
536 		INIT_LIST_HEAD(&res_pool->free_list);
537 		mutex_init(&res_pool->mutex);
538 	}
539 }
540 
541 static void fsl_mc_cleanup_resource_pool(struct fsl_mc_device *mc_bus_dev,
542 					 enum fsl_mc_pool_type pool_type)
543 {
544 	struct fsl_mc_resource *resource;
545 	struct fsl_mc_resource *next;
546 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
547 	struct fsl_mc_resource_pool *res_pool =
548 					&mc_bus->resource_pools[pool_type];
549 	int free_count = 0;
550 
551 	list_for_each_entry_safe(resource, next, &res_pool->free_list, node) {
552 		free_count++;
553 		devm_kfree(&mc_bus_dev->dev, resource);
554 	}
555 }
556 
557 void fsl_mc_cleanup_all_resource_pools(struct fsl_mc_device *mc_bus_dev)
558 {
559 	int pool_type;
560 
561 	for (pool_type = 0; pool_type < FSL_MC_NUM_POOL_TYPES; pool_type++)
562 		fsl_mc_cleanup_resource_pool(mc_bus_dev, pool_type);
563 }
564 
565 /**
566  * fsl_mc_allocator_probe - callback invoked when an allocatable device is
567  * being added to the system
568  */
569 static int fsl_mc_allocator_probe(struct fsl_mc_device *mc_dev)
570 {
571 	enum fsl_mc_pool_type pool_type;
572 	struct fsl_mc_device *mc_bus_dev;
573 	struct fsl_mc_bus *mc_bus;
574 	int error;
575 
576 	if (!fsl_mc_is_allocatable(mc_dev))
577 		return -EINVAL;
578 
579 	mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
580 	if (!dev_is_fsl_mc(&mc_bus_dev->dev))
581 		return -EINVAL;
582 
583 	mc_bus = to_fsl_mc_bus(mc_bus_dev);
584 	error = object_type_to_pool_type(mc_dev->obj_desc.type, &pool_type);
585 	if (error < 0)
586 		return error;
587 
588 	error = fsl_mc_resource_pool_add_device(mc_bus, pool_type, mc_dev);
589 	if (error < 0)
590 		return error;
591 
592 	dev_dbg(&mc_dev->dev,
593 		"Allocatable fsl-mc device bound to fsl_mc_allocator driver");
594 	return 0;
595 }
596 
597 /**
598  * fsl_mc_allocator_remove - callback invoked when an allocatable device is
599  * being removed from the system
600  */
601 static int fsl_mc_allocator_remove(struct fsl_mc_device *mc_dev)
602 {
603 	int error;
604 
605 	if (!fsl_mc_is_allocatable(mc_dev))
606 		return -EINVAL;
607 
608 	if (mc_dev->resource) {
609 		error = fsl_mc_resource_pool_remove_device(mc_dev);
610 		if (error < 0)
611 			return error;
612 	}
613 
614 	dev_dbg(&mc_dev->dev,
615 		"Allocatable fsl-mc device unbound from fsl_mc_allocator driver");
616 	return 0;
617 }
618 
619 static const struct fsl_mc_device_id match_id_table[] = {
620 	{
621 	 .vendor = FSL_MC_VENDOR_FREESCALE,
622 	 .obj_type = "dpbp",
623 	},
624 	{
625 	 .vendor = FSL_MC_VENDOR_FREESCALE,
626 	 .obj_type = "dpmcp",
627 	},
628 	{
629 	 .vendor = FSL_MC_VENDOR_FREESCALE,
630 	 .obj_type = "dpcon",
631 	},
632 	{.vendor = 0x0},
633 };
634 
635 static struct fsl_mc_driver fsl_mc_allocator_driver = {
636 	.driver = {
637 		   .name = "fsl_mc_allocator",
638 		   .pm = NULL,
639 		   },
640 	.match_id_table = match_id_table,
641 	.probe = fsl_mc_allocator_probe,
642 	.remove = fsl_mc_allocator_remove,
643 };
644 
645 int __init fsl_mc_allocator_driver_init(void)
646 {
647 	return fsl_mc_driver_register(&fsl_mc_allocator_driver);
648 }
649 
650 void fsl_mc_allocator_driver_exit(void)
651 {
652 	fsl_mc_driver_unregister(&fsl_mc_allocator_driver);
653 }
654