aboutsummaryrefslogtreecommitdiffstats
path: root/src/arch/arm64/armv8/secmon/psci.c
blob: 70251b2b06b8716a6d5b667f9e4d8d5fa88b7033 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
/*
 * This file is part of the coreboot project.
 *
 * Copyright 2014 Google Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
 */

#include <gic.h>
#include <string.h>
#include <stdlib.h>
#include <smp/spinlock.h>
#include <arch/cpu.h>
#include <arch/psci.h>
#include <arch/smc.h>
#include <arch/transition.h>
#include <arch/lib_helpers.h>
#include <console/console.h>
#include "secmon.h"

DECLARE_SPIN_LOCK(psci_spinlock);

/* Root of PSCI node tree. */
static struct psci_node psci_root;

/* Array of all the psci_nodes in system.  */
static size_t psci_num_nodes;
static struct psci_node **psci_nodes;

static inline void psci_lock(void)
{
	spin_lock(&psci_spinlock);
}

static inline void psci_unlock(void)
{
	spin_unlock(&psci_spinlock);
}

static inline int psci_state_locked(const struct psci_node *e)
{
	return e->state;
}

static inline void psci_set_state_locked(struct psci_node *e, int s)
{
	e->state = s;
}

static struct psci_node *psci_node_lookup(uint64_t mpidr, int level)
{
	size_t i;

	/* The array of node pointers are in depth-first order of the tree. */
	for (i = 0; i < psci_num_nodes; i++) {
		struct psci_node *current = psci_nodes[i];

		if (current->mpidr > mpidr)
			break;
		if (current->mpidr < mpidr)
			continue;
		if (current->level == level)
			return current;
	}
	return NULL;
}

static inline struct psci_node *node_self(void)
{
	return psci_node_lookup(cpu_info()->mpidr, PSCI_AFFINITY_LEVEL_0);
}

/* Find the ancestor of node affected by a state transition limited by level. */
static struct psci_node *psci_find_ancestor(struct psci_node *e, int level,
						int state)
{
	struct psci_node *p;

	/* If all siblings of the node are already off then parent can be
	 * set to off as well. */
	if (state == PSCI_STATE_OFF) {
		while (1) {
			size_t i;
			struct psci_node *s;

			if (psci_root_node(e))
				return e;

			p = psci_node_parent(e);

			if (p->level > level)
				return e;

			for (i = 0; i < p->children.num; i++) {
				s = &p->children.nodes[i];
				/* Don't check target. */
				if (s == e)
					continue;
				if (psci_state_locked(s) != PSCI_STATE_OFF)
					return e;
			}

			e = p;
		}
	}

	/* All ancestors in state OFF are affected. */
	if (state == PSCI_STATE_ON_PENDING) {
		while (1) {
			/* At the root. Return last affected node. */
			if (psci_root_node(e))
				return e;

			p = psci_node_parent(e);

			if (p->level > level)
				return e;

			/* This parent is already ON. */
			if (psci_state_locked(p) != PSCI_STATE_OFF)
				return e;

			e = p;
		}
	}

	/* Default to returning node passed in. */
	return e;
}

static void psci_set_hierarchy_state(struct psci_node *from,
					struct psci_node *to,
					int state)
{
	struct psci_node *end;

	end = psci_node_parent(to);

	while (from != end) {
		/* Raced with another CPU as state is already set. */
		if (psci_state_locked(from) == state)
			break;
		psci_set_state_locked(from, state);
		from = psci_node_parent(from);
	}
}

static void psci_cpu_on_callback(void *arg)
{
	struct exc_state state;
	int target_el;
	struct psci_node *e = arg;

	psci_lock();
	psci_set_hierarchy_state(e, e->cpu_state.ancestor, PSCI_STATE_ON);
	psci_unlock();

	/* Target EL is determined if HVC is enabled or not. */
	target_el = (raw_read_scr_el3() & SCR_HVC_ENABLE) ? EL2 : EL1;

	memset(&state, 0, sizeof(state));
	state.elx.spsr = get_eret_el(target_el, SPSR_USE_H);
	transition_with_entry(e->cpu_state.startup.run,
				e->cpu_state.startup.arg, &state);
}

static void psci_cpu_on_prepare(struct psci_cmd *cmd,
				const struct cpu_action *a)
{
	struct psci_node *ancestor;
	struct psci_node *e;
	int state = PSCI_STATE_ON_PENDING;

	e = cmd->target;
	e->cpu_state.startup = *a;
	ancestor = psci_find_ancestor(e, PSCI_AFFINITY_LEVEL_HIGHEST, state);
	e->cpu_state.ancestor = ancestor;
	cmd->ancestor = ancestor;
}

static int psci_schedule_cpu_on(struct psci_node *e)
{
	struct cpu_info *ci;
	struct cpu_action action = {
		.run = &psci_cpu_on_callback,
		.arg = e,
	};

	ci = e->cpu_state.ci;
	if (ci == NULL || arch_run_on_cpu_async(ci->id, &action)) {
		psci_set_hierarchy_state(e, e->cpu_state.ancestor,
						PSCI_STATE_OFF);
		return PSCI_RET_INTERNAL_FAILURE;
	}

	return PSCI_RET_SUCCESS;
}

void psci_turn_on_self(const struct cpu_action *action)
{
	struct psci_node *e = node_self();
	struct psci_cmd cmd = {
		.type = PSCI_CMD_ON,
	};

	if (e == NULL) {
		printk(BIOS_ERR, "Couldn't turn on self: mpidr %llx\n",
			cpu_info()->mpidr);
		return;
	}

	cmd.target = e;

	psci_lock();
	psci_cpu_on_prepare(&cmd, action);
	psci_set_hierarchy_state(e, cmd.ancestor, PSCI_STATE_ON_PENDING);
	psci_unlock();

	psci_schedule_cpu_on(e);
}

void psci_cpu_entry(void)
{
	gic_enable();
	/*
	 * Just wait for an action to be performed. Only CPU_ON is supported
	 * initially. i.e. no power down then wake.
	 */
	secmon_wait_for_action();
}

static void psci_cpu_on(struct psci_func *pf)
{
	uint64_t entry;
	uint64_t target_mpidr;
	uint64_t context_id;
	int cpu_state;
	int ret;
	struct psci_node *e;
	struct cpu_action action;
	struct psci_cmd cmd = {
		.type = PSCI_CMD_ON,
	};

	target_mpidr = psci64_arg(pf, PSCI_PARAM_0);
	entry = psci64_arg(pf, PSCI_PARAM_1);
	context_id = psci64_arg(pf, PSCI_PARAM_2);

	e = psci_node_lookup(target_mpidr, PSCI_AFFINITY_LEVEL_0);

	if (e == NULL) {
		psci32_return(pf, PSCI_RET_INVALID_PARAMETERS);
		return;
	}

	psci_lock();
	cpu_state = psci_state_locked(e);

	if (cpu_state == PSCI_STATE_ON_PENDING) {
		psci32_return(pf, PSCI_RET_ON_PENDING);
		psci_unlock();
		return;
	} else if (cpu_state == PSCI_STATE_ON) {
		psci32_return(pf, PSCI_RET_ALREADY_ON);
		psci_unlock();
		return;
	}

	cmd.target = e;
	action.run = (void *)entry;
	action.arg = (void *)context_id;
	psci_cpu_on_prepare(&cmd, &action);

	ret = soc_psci_ops.cmd_prepare(&cmd);

	if (ret == PSCI_RET_SUCCESS)
		psci_set_hierarchy_state(e, cmd.ancestor,
					PSCI_STATE_ON_PENDING);

	psci_unlock();

	if (ret != PSCI_RET_SUCCESS)
		return psci32_return(pf, ret);

	ret = soc_psci_ops.cmd_commit(&cmd);

	if (ret != PSCI_RET_SUCCESS) {
		psci_lock();
		psci_set_hierarchy_state(e, cmd.ancestor, PSCI_STATE_OFF);
		psci_unlock();
		return psci32_return(pf, ret);
	}

	psci32_return(pf, psci_schedule_cpu_on(e));
}

static int psci_turn_off_node(struct psci_node *e, int level,
					int state_id)
{
	int ret;
	struct psci_cmd cmd = {
		.type = PSCI_CMD_OFF,
		.state_id = state_id,
		.target = e,
	};

	psci_lock();

	cmd.ancestor = psci_find_ancestor(e, level, PSCI_STATE_OFF);

	ret = soc_psci_ops.cmd_prepare(&cmd);

	if (ret == PSCI_RET_SUCCESS)
		psci_set_hierarchy_state(e, cmd.ancestor, PSCI_STATE_OFF);

	psci_unlock();

	if (ret != PSCI_RET_SUCCESS)
		return ret;

	gic_disable();

	/* Should never return. */
	ret = soc_psci_ops.cmd_commit(&cmd);

	/* Adjust ret to be an error. */
	if (ret == PSCI_RET_SUCCESS)
		ret = PSCI_RET_INTERNAL_FAILURE;

	/* Turn things back on. */
	psci_lock();
	psci_set_hierarchy_state(e, cmd.ancestor, PSCI_STATE_ON);
	psci_unlock();

	return ret;
}

int psci_turn_off_self(void)
{
	struct psci_node *e = node_self();

	if (e == NULL) {
		printk(BIOS_ERR, "No PSCI node for MPIDR %llx.\n",
			cpu_info()->mpidr);
		return PSCI_RET_INTERNAL_FAILURE;
	}

	/* -1 state id indicates to SoC to make its own decision for
	 * internal state when powering off the node. */
	return psci_turn_off_node(e, PSCI_AFFINITY_LEVEL_HIGHEST, -1);
}

static int psci_handler(struct smc_call *smc)
{
	struct psci_func pf_storage;
	struct psci_func *pf = &pf_storage;

	psci_func_init(pf, smc);

	switch (pf->id) {
	case PSCI_CPU_ON64:
		psci_cpu_on(pf);
		break;
	case PSCI_CPU_OFF32:
		psci32_return(pf, psci_turn_off_self());
		break;
	default:
		psci32_return(pf, PSCI_RET_NOT_SUPPORTED);
		break;
	}

	return 0;
}

static void psci_link_cpu_info(void *arg)
{
	struct psci_node *e = node_self();

	if (e == NULL) {
		printk(BIOS_ERR, "No PSCI node for MPIDR %llx.\n",
			cpu_info()->mpidr);
		return;
	}

	e->cpu_state.ci = cpu_info();
}

static int psci_init_node(struct psci_node *e,
				struct psci_node *parent,
				int level, uint64_t mpidr)
{
	size_t i;
	uint64_t mpidr_inc;
	struct psci_node_group *ng;
	size_t num_children;

	memset(e, 0, sizeof(*e));
	e->mpidr = mpidr;
	psci_set_state_locked(e, PSCI_STATE_OFF);
	e->parent = parent;
	e->level = level;

	if (level == PSCI_AFFINITY_LEVEL_0)
		return 0;

	num_children = soc_psci_ops.children_at_level(level, mpidr);

	if (num_children == 0)
		return 0;

	ng = &e->children;
	ng->num = num_children;
	ng->nodes = malloc(ng->num * sizeof(struct psci_node));
	if (ng->nodes == NULL) {
		printk(BIOS_DEBUG, "PSCI: Allocation failure at level %d\n",
			level);
		return -1;
	}

	/* Switch to next level below. */
	level = psci_level_below(level);
	mpidr_inc = mpidr_mask(!!(level == PSCI_AFFINITY_LEVEL_3),
				!!(level == PSCI_AFFINITY_LEVEL_2),
				!!(level == PSCI_AFFINITY_LEVEL_1),
				!!(level == PSCI_AFFINITY_LEVEL_0));

	for (i = 0; i < ng->num; i++) {
		struct psci_node *c = &ng->nodes[i];

		/* Recursively initialize the nodes. */
		if (psci_init_node(c, e, level, mpidr))
			return -1;
		mpidr += mpidr_inc;
	}

	return 0;
}

static size_t psci_count_children(struct psci_node *e)
{
	size_t i;
	size_t count;

	if (e->level == PSCI_AFFINITY_LEVEL_0)
		return 0;

	count = e->children.num;
	for (i = 0; i < e->children.num; i++)
		count +=  psci_count_children(&e->children.nodes[i]);

	return count;
}

static size_t psci_write_nodes(struct psci_node *e, size_t index)
{
	size_t i;

	/*
	 * Recursively save node pointers in array. Node pointers are
	 * ordered in ascending mpidr and descending level within same mpidr.
	 * i.e. each node is saved in depth-first order of the tree.
	 */
	if (e->level != PSCI_AFFINITY_ROOT) {
		psci_nodes[index] = e;
		index++;
	}

	if (e->level == PSCI_AFFINITY_LEVEL_0)
		return index;

	for (i = 0; i < e->children.num; i++)
		index = psci_write_nodes(&e->children.nodes[i], index);

	return index;
}

static int psci_allocate_nodes(void)
{
	int level;
	size_t num_children;
	uint64_t mpidr;
	struct psci_node *e;

	mpidr = 0;
	level = PSCI_AFFINITY_ROOT;

	/* Find where the root should start. */
	while (psci_level_below(level) >= PSCI_AFFINITY_LEVEL_0) {
		num_children = soc_psci_ops.children_at_level(level, mpidr);

		if (num_children == 0) {
			printk(BIOS_ERR, "PSCI: No children at level %d!\n",
				level);
			return -1;
		}

		/* The root starts where the affinity levels branch. */
		if (num_children > 1)
			break;

		level = psci_level_below(level);
	}

	if (psci_init_node(&psci_root, NULL, level, mpidr)) {
		printk(BIOS_ERR, "PSCI init node failure.\n");
		return -1;
	}

	num_children = psci_count_children(&psci_root);
	/* Count the root node if isn't a fake node. */
	if (psci_root.level != PSCI_AFFINITY_ROOT)
		num_children++;

	psci_nodes = malloc(num_children * sizeof(void *));
	psci_num_nodes = num_children;

	if (psci_nodes == NULL) {
		printk(BIOS_ERR, "PSCI node pointer array failure.\n");
		return -1;
	}

	num_children = psci_write_nodes(&psci_root, 0);
	if (num_children != psci_num_nodes) {
		printk(BIOS_ERR, "Wrong nodes written: %zd vs %zd.\n",
			num_children, psci_num_nodes);
		return -1;
	}

	/*
	 * By default all nodes are set to PSCI_STATE_OFF. In order not
	 * to race with other CPUs turning themselves off set the BSPs
	 * affinity node to ON.
	 */
	e = node_self();
	if (e == NULL) {
		printk(BIOS_ERR, "No PSCI node for BSP.\n");
		return -1;
	}
	psci_set_state_locked(e, PSCI_STATE_ON);

	return 0;
}

void psci_init(uintptr_t cpu_on_entry)
{
	struct cpu_action action = {
		.run = &psci_link_cpu_info,
	};

	if (psci_allocate_nodes()) {
		printk(BIOS_ERR, "PSCI support not enabled.\n");
		return;
	}

	if (arch_run_on_all_cpus_async(&action))
		printk(BIOS_ERR, "Error linking cpu_info to PSCI nodes.\n");

	/* Register PSCI handlers. */
	if (smc_register_range(PSCI_CPU_SUSPEND32, PSCI_CPU_ON32,
			       &psci_handler))
		printk(BIOS_ERR, "Couldn't register PSCI handler.\n");

	if (smc_register_range(PSCI_CPU_SUSPEND64, PSCI_CPU_ON64,
			       &psci_handler))
		printk(BIOS_ERR, "Couldn't register PSCI handler.\n");

	/* Inform SoC layer of CPU_ON entry point. */
	psci_soc_init(cpu_on_entry);
}