1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2021, Linaro Limited
4  * Copyright (c) 2021, Bootlin
5  * Copyright (c) 2021, Linaro Limited
6  * Copyright (c) 2021, STMicroelectronics
7  */
8 
9 #include <assert.h>
10 #include <config.h>
11 #include <initcall.h>
12 #include <kernel/boot.h>
13 #include <kernel/dt.h>
14 #include <kernel/dt_driver.h>
15 #include <libfdt.h>
16 #include <malloc.h>
17 #include <sys/queue.h>
18 #include <tee_api_defines_extensions.h>
19 #include <tee_api_types.h>
20 
21 /*
22  * struct dt_driver_probe - Node instance in secure FDT to probe a driver for
23  *
24  * @link: List hook
25  * @nodeoffset: Node offset of device referenced in the FDT
26  * @type: One of DT_DRIVER_* or DT_DRIVER_NOTYPE.
27  * @deferrals: Driver probe deferrals count
28  * @dt_drv: Matching driver to probe if found or NULL
29  * @dm: Matching reference if applicable or NULL
30  */
31 struct dt_driver_probe {
32 	int nodeoffset;
33 	enum dt_driver_type type;
34 	unsigned int deferrals;
35 	const struct dt_driver *dt_drv;
36 	const struct dt_device_match *dm;
37 	TAILQ_ENTRY(dt_driver_probe) link;
38 };
39 
40 /*
41  * struct dt_driver_provider - DT related info on probed device
42  *
43  * Saves information on the probed device so that device
44  * drivers can get resources from DT phandle and related arguments.
45  *
46  * @nodeoffset: Node offset of device referenced in the FDT
47  * @type: One of DT_DRIVER_* or DT_DRIVER_NOTYPE.
48  * @provider_cells: Cells count in the FDT used by the driver's references
49  * @get_of_device: Function to get driver's device ref from phandle data
50  * @priv_data: Driver private data passed as @get_of_device argument
51  * @link: Reference in DT driver providers list
52  */
53 struct dt_driver_provider {
54 	int nodeoffset;
55 	enum dt_driver_type type;
56 	unsigned int provider_cells;
57 	uint32_t phandle;
58 	get_of_device_func get_of_device;
59 	void *priv_data;
60 	SLIST_ENTRY(dt_driver_provider) link;
61 };
62 
63 /*
64  * Device driver providers are able to provide a driver specific instance
65  * related to device phandle arguments found in the secure embedded FDT.
66  */
67 static SLIST_HEAD(, dt_driver_provider) dt_driver_provider_list =
68 	SLIST_HEAD_INITIALIZER(dt_driver_provider_list);
69 
70 /* FDT nodes for which a matching driver is to be probed */
71 static TAILQ_HEAD(dt_driver_probe_head, dt_driver_probe) dt_driver_probe_list =
72 	TAILQ_HEAD_INITIALIZER(dt_driver_probe_list);
73 
74 /* FDT nodes for which a matching driver has been successfully probed */
75 static TAILQ_HEAD(, dt_driver_probe) dt_driver_ready_list =
76 	TAILQ_HEAD_INITIALIZER(dt_driver_ready_list);
77 
78 /* List of the nodes for which a compatible driver but reported a failure */
79 static TAILQ_HEAD(, dt_driver_probe) dt_driver_failed_list =
80 	TAILQ_HEAD_INITIALIZER(dt_driver_failed_list);
81 
82 /* Flag enabled when a new node (possibly typed) is added in the probe list */
83 static bool added_node;
84 
85 /* Resolve drivers dependencies on core crypto layer */
86 static bool tee_crypt_is_ready;
87 
dt_driver_crypt_init_complete(void)88 void dt_driver_crypt_init_complete(void)
89 {
90 	assert(!tee_crypt_is_ready);
91 	tee_crypt_is_ready = true;
92 }
93 
dt_driver_get_crypto(void)94 TEE_Result dt_driver_get_crypto(void)
95 {
96 	if (tee_crypt_is_ready)
97 		return TEE_SUCCESS;
98 	else
99 		return TEE_ERROR_DEFER_DRIVER_INIT;
100 }
101 
assert_type_is_valid(enum dt_driver_type type)102 static void assert_type_is_valid(enum dt_driver_type type)
103 {
104 	switch (type) {
105 	case DT_DRIVER_NOTYPE:
106 	case DT_DRIVER_CLK:
107 	case DT_DRIVER_RSTCTRL:
108 	case DT_DRIVER_UART:
109 		return;
110 	default:
111 		assert(0);
112 	}
113 }
114 
115 /*
116  * Driver provider registering API functions
117  */
118 
dt_driver_register_provider(const void * fdt,int nodeoffset,get_of_device_func get_of_device,void * priv,enum dt_driver_type type)119 TEE_Result dt_driver_register_provider(const void *fdt, int nodeoffset,
120 				       get_of_device_func get_of_device,
121 				       void *priv, enum dt_driver_type type)
122 {
123 	struct dt_driver_provider *prv = NULL;
124 	int provider_cells = 0;
125 	uint32_t phandle = 0;
126 
127 	assert_type_is_valid(type);
128 
129 	provider_cells = fdt_get_dt_driver_cells(fdt, nodeoffset, type);
130 	if (provider_cells < 0) {
131 		DMSG("Failed to find provider cells: %d", provider_cells);
132 		return TEE_ERROR_GENERIC;
133 	}
134 
135 	phandle = fdt_get_phandle(fdt, nodeoffset);
136 	if (!phandle || phandle == (uint32_t)-1) {
137 		DMSG("Failed to find provide phandle");
138 		return TEE_ERROR_GENERIC;
139 	}
140 
141 	prv = calloc(1, sizeof(*prv));
142 	if (!prv)
143 		return TEE_ERROR_OUT_OF_MEMORY;
144 
145 	prv->nodeoffset = nodeoffset;
146 	prv->type = type;
147 	prv->provider_cells = provider_cells;
148 	prv->phandle = phandle;
149 	prv->get_of_device = get_of_device;
150 	prv->priv_data = priv;
151 
152 	SLIST_INSERT_HEAD(&dt_driver_provider_list, prv, link);
153 
154 	return TEE_SUCCESS;
155 }
156 
157 /*
158  * Helper functions for dt_drivers querying driver provider information
159  */
160 
fdt_get_dt_driver_cells(const void * fdt,int nodeoffset,enum dt_driver_type type)161 int fdt_get_dt_driver_cells(const void *fdt, int nodeoffset,
162 			    enum dt_driver_type type)
163 {
164 	const char *cells_name = NULL;
165 	const fdt32_t *c = NULL;
166 	int len = 0;
167 
168 	switch (type) {
169 	case DT_DRIVER_CLK:
170 		cells_name = "#clock-cells";
171 		break;
172 	case DT_DRIVER_RSTCTRL:
173 		cells_name = "#reset-cells";
174 		break;
175 	default:
176 		panic();
177 	}
178 
179 	c = fdt_getprop(fdt, nodeoffset, cells_name, &len);
180 	if (!c)
181 		return len;
182 
183 	if (len != sizeof(*c))
184 		return -FDT_ERR_BADNCELLS;
185 
186 	return fdt32_to_cpu(*c);
187 }
188 
dt_driver_provider_cells(struct dt_driver_provider * prv)189 unsigned int dt_driver_provider_cells(struct dt_driver_provider *prv)
190 {
191 	return prv->provider_cells;
192 }
193 
194 struct dt_driver_provider *
dt_driver_get_provider_by_node(int nodeoffset,enum dt_driver_type type)195 dt_driver_get_provider_by_node(int nodeoffset, enum dt_driver_type type)
196 {
197 	struct dt_driver_provider *prv = NULL;
198 
199 	SLIST_FOREACH(prv, &dt_driver_provider_list, link)
200 		if (prv->nodeoffset == nodeoffset && prv->type == type)
201 			return prv;
202 
203 	return NULL;
204 }
205 
206 struct dt_driver_provider *
dt_driver_get_provider_by_phandle(uint32_t phandle,enum dt_driver_type type)207 dt_driver_get_provider_by_phandle(uint32_t phandle, enum dt_driver_type type)
208 {
209 	struct dt_driver_provider *prv = NULL;
210 
211 	SLIST_FOREACH(prv, &dt_driver_provider_list, link)
212 		if (prv->phandle == phandle && prv->type == type)
213 			return prv;
214 
215 	return NULL;
216 }
217 
device_from_provider_prop(struct dt_driver_provider * prv,const uint32_t * prop,TEE_Result * res)218 static void *device_from_provider_prop(struct dt_driver_provider *prv,
219 					  const uint32_t *prop,
220 					  TEE_Result *res)
221 {
222 	struct dt_driver_phandle_args *pargs = NULL;
223 	unsigned int n = 0;
224 	void *device = NULL;
225 
226 	pargs = calloc(1, prv->provider_cells * sizeof(uint32_t *) +
227 		       sizeof(*pargs));
228 	if (!pargs) {
229 		*res = TEE_ERROR_OUT_OF_MEMORY;
230 		return NULL;
231 	}
232 
233 	pargs->args_count = prv->provider_cells;
234 	for (n = 0; n < prv->provider_cells; n++)
235 		pargs->args[n] = fdt32_to_cpu(prop[n + 1]);
236 
237 	device = prv->get_of_device(pargs, prv->priv_data, res);
238 
239 	free(pargs);
240 
241 	return device;
242 }
243 
dt_driver_device_from_node_idx_prop(const char * prop_name,const void * fdt,int nodeoffset,unsigned int prop_idx,enum dt_driver_type type,TEE_Result * res)244 void *dt_driver_device_from_node_idx_prop(const char *prop_name,
245 					  const void *fdt, int nodeoffset,
246 					  unsigned int prop_idx,
247 					  enum dt_driver_type type,
248 					  TEE_Result *res)
249 {
250 	int len = 0;
251 	int idx = 0;
252 	int idx32 = 0;
253 	int prv_cells = 0;
254 	uint32_t phandle = 0;
255 	const uint32_t *prop = NULL;
256 	struct dt_driver_provider *prv = NULL;
257 
258 	prop = fdt_getprop(fdt, nodeoffset, prop_name, &len);
259 	if (!prop) {
260 		DMSG("Property %s missing in node %s", prop_name,
261 		     fdt_get_name(fdt, nodeoffset, NULL));
262 		*res = TEE_ERROR_GENERIC;
263 		return NULL;
264 	}
265 
266 	while (idx < len) {
267 		idx32 = idx / sizeof(uint32_t);
268 		phandle = fdt32_to_cpu(prop[idx32]);
269 
270 		prv = dt_driver_get_provider_by_phandle(phandle, type);
271 		if (!prv) {
272 			/* No provider registered yet */
273 			*res = TEE_ERROR_DEFER_DRIVER_INIT;
274 			return NULL;
275 		}
276 
277 		prv_cells = dt_driver_provider_cells(prv);
278 		if (prop_idx) {
279 			prop_idx--;
280 			idx += sizeof(phandle) + prv_cells * sizeof(uint32_t);
281 			continue;
282 		}
283 
284 		return device_from_provider_prop(prv, prop + idx32, res);
285 	}
286 
287 	*res = TEE_ERROR_GENERIC;
288 	return NULL;
289 }
290 
print_probe_list(const void * fdt __maybe_unused)291 static void __maybe_unused print_probe_list(const void *fdt __maybe_unused)
292 {
293 	struct dt_driver_probe *elt = NULL;
294 	unsigned int count = 0;
295 
296 	TAILQ_FOREACH(elt, &dt_driver_probe_list, link)
297 		count++;
298 
299 	DMSG("Probe list: %u elements", count);
300 	TAILQ_FOREACH(elt, &dt_driver_probe_list, link)
301 		DMSG("|- Driver %s probes on node %s",
302 		     elt->dt_drv->name,
303 		     fdt_get_name(fdt, elt->nodeoffset, NULL));
304 
305 	DMSG("`- Probe list end");
306 
307 	count = 0;
308 	TAILQ_FOREACH(elt, &dt_driver_failed_list, link)
309 		count++;
310 
311 	DMSG("Failed list: %u elements", count);
312 	TAILQ_FOREACH(elt, &dt_driver_failed_list, link)
313 		EMSG("|- Driver %s on node %s failed", elt->dt_drv->name,
314 		     fdt_get_name(fdt, elt->nodeoffset, NULL));
315 
316 	DMSG("`- Failed list end");
317 }
318 
319 /*
320  * Probe element: push to ready list if succeeds, push to probe list if probe
321  * if deferred, panic with an error trace otherwise.
322  */
probe_driver_node(const void * fdt,struct dt_driver_probe * elt)323 static TEE_Result probe_driver_node(const void *fdt,
324 				    struct dt_driver_probe *elt)
325 {
326 	TEE_Result res = TEE_ERROR_GENERIC;
327 	const char __maybe_unused *drv_name = NULL;
328 	const char __maybe_unused *node_name = NULL;
329 
330 	node_name = fdt_get_name(fdt, elt->nodeoffset, NULL);
331 	drv_name = elt->dt_drv->name;
332 
333 	if (!elt->dt_drv->probe) {
334 		DMSG("No probe operator for driver %s, skipped", drv_name);
335 		return TEE_SUCCESS;
336 	}
337 
338 	FMSG("Probing %s on node %s", drv_name, node_name);
339 
340 	res = elt->dt_drv->probe(fdt, elt->nodeoffset, elt->dm->compat_data);
341 	switch (res) {
342 	case TEE_SUCCESS:
343 		TAILQ_INSERT_HEAD(&dt_driver_ready_list, elt, link);
344 
345 		DMSG("element: %s on node %s initialized", drv_name, node_name);
346 		break;
347 	case TEE_ERROR_DEFER_DRIVER_INIT:
348 		elt->deferrals++;
349 		TAILQ_INSERT_TAIL(&dt_driver_probe_list, elt, link);
350 
351 		DMSG("element: %s on node %s deferred %u time(s)", drv_name,
352 		     node_name, elt->deferrals);
353 		break;
354 	default:
355 		TAILQ_INSERT_HEAD(&dt_driver_failed_list, elt, link);
356 
357 		EMSG("Failed to probe %s on node %s: %#"PRIx32,
358 		     drv_name, node_name, res);
359 		break;
360 	}
361 
362 	return res;
363 }
364 
alloc_elt_and_probe(const void * fdt,int node,const struct dt_driver * dt_drv,const struct dt_device_match * dm)365 static TEE_Result alloc_elt_and_probe(const void *fdt, int node,
366 				      const struct dt_driver *dt_drv,
367 				      const struct dt_device_match *dm)
368 {
369 	struct dt_driver_probe *elt = NULL;
370 
371 	/* Will be freed when lists are released */
372 	elt = calloc(1, sizeof(*elt));
373 	if (!elt)
374 		return TEE_ERROR_OUT_OF_MEMORY;
375 
376 	elt->nodeoffset = node;
377 	elt->dt_drv = dt_drv;
378 	elt->dm = dm;
379 	elt->type = dt_drv->type;
380 
381 	return probe_driver_node(fdt, elt);
382 }
383 
384 /* Lookup a compatible driver, possibly of a specific @type, for the FDT node */
probe_device_by_compat(const void * fdt,int node,const char * compat,enum dt_driver_type type)385 static TEE_Result probe_device_by_compat(const void *fdt, int node,
386 					 const char *compat,
387 					 enum dt_driver_type type)
388 {
389 	const struct dt_driver *drv = NULL;
390 	const struct dt_device_match *dm = NULL;
391 
392 	for_each_dt_driver(drv) {
393 		if (drv->type != type)
394 			continue;
395 
396 		for (dm = drv->match_table; dm && dm->compatible; dm++)
397 			if (strcmp(dm->compatible, compat) == 0)
398 				return alloc_elt_and_probe(fdt, node, drv, dm);
399 	}
400 
401 	return TEE_ERROR_ITEM_NOT_FOUND;
402 }
403 
404 /*
405  * Lookup the best matching compatible driver, possibly of a specific @type,
406  * for the FDT node.
407  */
dt_driver_probe_device_by_node(const void * fdt,int nodeoffset,enum dt_driver_type type)408 TEE_Result dt_driver_probe_device_by_node(const void *fdt, int nodeoffset,
409 					  enum dt_driver_type type)
410 {
411 	int idx = 0;
412 	int len = 0;
413 	int count = 0;
414 	const char *compat = NULL;
415 	TEE_Result res = TEE_ERROR_GENERIC;
416 
417 	assert_type_is_valid(type);
418 
419 	count = fdt_stringlist_count(fdt, nodeoffset, "compatible");
420 	if (count < 0)
421 		return TEE_ERROR_ITEM_NOT_FOUND;
422 
423 	for (idx = 0; idx < count; idx++) {
424 		compat = fdt_stringlist_get(fdt, nodeoffset, "compatible",
425 					    idx, &len);
426 		if (!compat)
427 			return TEE_ERROR_GENERIC;
428 
429 		res = probe_device_by_compat(fdt, nodeoffset, compat, type);
430 
431 		if (res != TEE_ERROR_ITEM_NOT_FOUND)
432 			return res;
433 	}
434 
435 	return TEE_ERROR_ITEM_NOT_FOUND;
436 }
437 
process_probe_list(const void * fdt)438 static TEE_Result process_probe_list(const void *fdt)
439 {
440 	struct dt_driver_probe *elt = NULL;
441 	struct dt_driver_probe *prev = NULL;
442 	static unsigned int __maybe_unused loop_count;
443 	static unsigned int __maybe_unused deferral_loop_count;
444 	bool __maybe_unused one_deferred = false;
445 	bool one_probed_ok = false;
446 
447 	do {
448 		loop_count++;
449 		FMSG("Probe loop %u after %u for deferral(s)", loop_count,
450 		     deferral_loop_count);
451 
452 		/* Hack here for TRACE_DEBUG messages on probe list elements */
453 		if (TRACE_LEVEL >= TRACE_FLOW)
454 			print_probe_list(fdt);
455 
456 		if (TAILQ_EMPTY(&dt_driver_probe_list))
457 			return TEE_SUCCESS;
458 
459 		/*
460 		 * Probe from current end to top. Deferred probed node are
461 		 * pushed back after current tail for the next probe round.
462 		 * Reset probe result flags and see status after probe round.
463 		 */
464 		one_deferred = false;
465 		one_probed_ok = false;
466 		added_node = false;
467 
468 		TAILQ_FOREACH_REVERSE_SAFE(elt, &dt_driver_probe_list,
469 					   dt_driver_probe_head, link, prev) {
470 			TAILQ_REMOVE(&dt_driver_probe_list, elt, link);
471 
472 			switch (probe_driver_node(fdt, elt)) {
473 			case TEE_SUCCESS:
474 				one_probed_ok = true;
475 				break;
476 			case TEE_ERROR_DEFER_DRIVER_INIT:
477 				one_deferred = true;
478 				break;
479 			default:
480 				break;
481 			}
482 		}
483 
484 		if (one_deferred)
485 			deferral_loop_count++;
486 
487 	} while (added_node || one_probed_ok);
488 
489 	DMSG("Unresolved dependencies after %u rounds, %u deferred",
490 	     loop_count, deferral_loop_count);
491 
492 	if (one_deferred)
493 		return TEE_ERROR_DEFER_DRIVER_INIT;
494 	else
495 		return TEE_ERROR_GENERIC;
496 }
497 
driver_probe_compare(struct dt_driver_probe * candidate,struct dt_driver_probe * elt)498 static int driver_probe_compare(struct dt_driver_probe *candidate,
499 				struct dt_driver_probe *elt)
500 {
501 	if (candidate->nodeoffset != elt->nodeoffset ||
502 	    candidate->type != elt->type)
503 		return 1;
504 
505 	assert(elt->dt_drv == candidate->dt_drv);
506 	return 0;
507 }
508 
509 /*
510  * Return TEE_SUCCESS if compatible found
511  *	  TEE_ERROR_OUT_OF_MEMORY if heap is exhausted
512  */
add_node_to_probe(const void * fdt,int node,const struct dt_driver * dt_drv,const struct dt_device_match * dm)513 static TEE_Result add_node_to_probe(const void *fdt, int node,
514 				    const struct dt_driver *dt_drv,
515 				    const struct dt_device_match *dm)
516 {
517 	const char __maybe_unused *node_name = fdt_get_name(fdt, node, NULL);
518 	const char __maybe_unused *drv_name = dt_drv->name;
519 	struct dt_driver_probe *elt = NULL;
520 	struct dt_driver_probe elt_new = {
521 		.dm = dm,
522 		.dt_drv = dt_drv,
523 		.nodeoffset = node,
524 		.type = dt_drv->type,
525 	};
526 
527 	/* If node/type found in probe list or ready list, nothing to do */
528 	TAILQ_FOREACH(elt, &dt_driver_probe_list, link)
529 		if (!driver_probe_compare(&elt_new, elt))
530 			return TEE_SUCCESS;
531 
532 	TAILQ_FOREACH(elt, &dt_driver_ready_list, link)
533 		if (!driver_probe_compare(&elt_new, elt))
534 			return TEE_SUCCESS;
535 
536 	elt = malloc(sizeof(*elt));
537 	if (!elt)
538 		return TEE_ERROR_OUT_OF_MEMORY;
539 
540 	DMSG("element: %s on node %s", node_name, drv_name);
541 
542 	memcpy(elt, &elt_new, sizeof(*elt));
543 
544 	added_node = true;
545 
546 	TAILQ_INSERT_TAIL(&dt_driver_probe_list, elt, link);
547 
548 	/* Hack here for TRACE_DEBUG messages on current probe list elements */
549 	if (TRACE_LEVEL >= TRACE_FLOW)
550 		print_probe_list(fdt);
551 
552 	return TEE_SUCCESS;
553 }
554 
555 /*
556  * Add a node to the probe list if a dt_driver matches target compatible.
557  *
558  * If @type is DT_DRIVER_ANY, probe list can hold only 1 driver to probe for
559  * the node. A node may probe several drivers if have a unique driver type.
560  *
561  * Return TEE_SUCCESS if compatible found
562  *	  TEE_ERROR_ITEM_NOT_FOUND if no matching driver
563  *	  TEE_ERROR_OUT_OF_MEMORY if heap is exhausted
564  */
add_probe_node_by_compat(const void * fdt,int node,const char * compat)565 static TEE_Result add_probe_node_by_compat(const void *fdt, int node,
566 					   const char *compat)
567 {
568 	TEE_Result res = TEE_ERROR_ITEM_NOT_FOUND;
569 	const struct dt_driver *dt_drv = NULL;
570 	const struct dt_device_match *dm = NULL;
571 	uint32_t found_types = 0;
572 
573 	for_each_dt_driver(dt_drv) {
574 		for (dm = dt_drv->match_table; dm && dm->compatible; dm++) {
575 			if (strcmp(dm->compatible, compat) == 0) {
576 				assert(dt_drv->type < 32);
577 
578 				res = add_node_to_probe(fdt, node, dt_drv, dm);
579 				if (res)
580 					return res;
581 
582 				if (found_types & BIT(dt_drv->type)) {
583 					EMSG("Driver %s multi hit on type %u",
584 					     dt_drv->name, dt_drv->type);
585 					panic();
586 				}
587 				found_types |= BIT(dt_drv->type);
588 
589 				/* Matching found for this driver, try next */
590 				break;
591 			}
592 		}
593 	}
594 
595 	return res;
596 }
597 
598 /*
599  * Add the node to the probe list if matching compatible drivers are found.
600  * Follow node's compatible property list ordering to find matching driver.
601  */
dt_driver_maybe_add_probe_node(const void * fdt,int node)602 TEE_Result dt_driver_maybe_add_probe_node(const void *fdt, int node)
603 {
604 	int idx = 0;
605 	int len = 0;
606 	int count = 0;
607 	const char *compat = NULL;
608 	TEE_Result res = TEE_ERROR_GENERIC;
609 
610 	if (_fdt_get_status(fdt, node) == DT_STATUS_DISABLED)
611 		return TEE_SUCCESS;
612 
613 	count = fdt_stringlist_count(fdt, node, "compatible");
614 	if (count < 0)
615 		return TEE_SUCCESS;
616 
617 	for (idx = 0; idx < count; idx++) {
618 		compat = fdt_stringlist_get(fdt, node, "compatible", idx, &len);
619 		assert(compat && len > 0);
620 
621 		res = add_probe_node_by_compat(fdt, node, compat);
622 
623 		/* Stop lookup if something was found */
624 		if (res != TEE_ERROR_ITEM_NOT_FOUND)
625 			return res;
626 	}
627 
628 	return TEE_SUCCESS;
629 }
630 
parse_node(const void * fdt,int node)631 static void parse_node(const void *fdt, int node)
632 {
633 	TEE_Result __maybe_unused res = TEE_ERROR_GENERIC;
634 	int subnode = 0;
635 
636 	fdt_for_each_subnode(subnode, fdt, node) {
637 		res = dt_driver_maybe_add_probe_node(fdt, subnode);
638 		if (res) {
639 			EMSG("Failed on node %s with %#"PRIx32,
640 			     fdt_get_name(fdt, subnode, NULL), res);
641 			panic();
642 		}
643 
644 		/*
645 		 * Rescursively parse the FDT, skipping disabled nodes.
646 		 * FDT is expected reliable and core shall have sufficient
647 		 * stack depth to possibly parse all DT nodes.
648 		 */
649 		if (IS_ENABLED(CFG_DRIVERS_DT_RECURSIVE_PROBE)) {
650 			if (_fdt_get_status(fdt, subnode) == DT_STATUS_DISABLED)
651 				continue;
652 
653 			parse_node(fdt, subnode);
654 		}
655 	}
656 }
657 
658 /*
659  * Parse FDT for nodes and save in probe list the node for which a dt_driver
660  * matches node's compatible property.
661  */
probe_dt_drivers_early(void)662 static TEE_Result probe_dt_drivers_early(void)
663 {
664 	TEE_Result res = TEE_ERROR_GENERIC;
665 	const void *fdt = NULL;
666 
667 	if (!IS_ENABLED(CFG_EMBED_DTB))
668 		return TEE_SUCCESS;
669 
670 	fdt = get_embedded_dt();
671 	assert(fdt);
672 
673 	parse_node(fdt, fdt_path_offset(fdt, "/"));
674 
675 	res = process_probe_list(fdt);
676 	if (res == TEE_ERROR_DEFER_DRIVER_INIT) {
677 		DMSG("Deferred drivers probing");
678 		print_probe_list(fdt);
679 		res = TEE_SUCCESS;
680 	}
681 
682 	return res;
683 }
684 
probe_dt_drivers(void)685 static TEE_Result probe_dt_drivers(void)
686 {
687 	TEE_Result res = TEE_ERROR_GENERIC;
688 	const void *fdt = NULL;
689 
690 	if (!IS_ENABLED(CFG_EMBED_DTB))
691 		return TEE_SUCCESS;
692 
693 	fdt = get_embedded_dt();
694 	assert(fdt);
695 
696 	res = process_probe_list(fdt);
697 	if (res || !TAILQ_EMPTY(&dt_driver_failed_list)) {
698 		EMSG("Probe sequence result: %#"PRIx32, res);
699 		print_probe_list(fdt);
700 	}
701 	if (res)
702 		panic();
703 
704 	return TEE_SUCCESS;
705 }
706 
707 early_init_late(probe_dt_drivers_early);
708 driver_init(probe_dt_drivers);
709 
release_probe_lists(void)710 static TEE_Result release_probe_lists(void)
711 {
712 	struct dt_driver_probe *elt = NULL;
713 	struct dt_driver_probe *next = NULL;
714 	struct dt_driver_provider *prov = NULL;
715 	struct dt_driver_provider *next_prov = NULL;
716 	const void * __maybe_unused fdt = NULL;
717 
718 	if (!IS_ENABLED(CFG_EMBED_DTB))
719 		return TEE_SUCCESS;
720 
721 	fdt = get_embedded_dt();
722 
723 	assert(fdt && TAILQ_EMPTY(&dt_driver_probe_list));
724 
725 	TAILQ_FOREACH_SAFE(elt, &dt_driver_ready_list, link, next)
726 		free(elt);
727 
728 	TAILQ_FOREACH_SAFE(elt, &dt_driver_failed_list, link, next)
729 	       free(elt);
730 
731 	SLIST_FOREACH_SAFE(prov, &dt_driver_provider_list, link, next_prov)
732 	       free(prov);
733 
734 	return TEE_SUCCESS;
735 }
736 
737 release_init_resource(release_probe_lists);
738 
739 /*
740  * Simple bus support: handy to parse subnodes
741  */
simple_bus_probe(const void * fdt,int node,const void * compat_data __unused)742 static TEE_Result simple_bus_probe(const void *fdt, int node,
743 				   const void *compat_data __unused)
744 {
745 	TEE_Result res = TEE_ERROR_GENERIC;
746 	int subnode = 0;
747 
748 	fdt_for_each_subnode(subnode, fdt, node) {
749 		res = dt_driver_maybe_add_probe_node(fdt, subnode);
750 		if (res) {
751 			EMSG("Failed on node %s with %#"PRIx32,
752 			     fdt_get_name(fdt, subnode, NULL), res);
753 			panic();
754 		}
755 	}
756 
757 	return TEE_SUCCESS;
758 }
759 
760 static const struct dt_device_match simple_bus_match_table[] = {
761 	{ .compatible = "simple-bus" },
762 	{ }
763 };
764 
765 DEFINE_DT_DRIVER(simple_bus_dt_driver) = {
766 	.name = "simple-bus",
767 	.match_table = simple_bus_match_table,
768 	.probe = simple_bus_probe,
769 };
770