summaryrefslogtreecommitdiff
path: root/drivers/acpi/arm64/gtdt.c
blob: 01962c63a7116ee3b58df8ccdb52818d6d9f1019 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ARM Specific GTDT table Support
 *
 * Copyright (C) 2016, Linaro Ltd.
 * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
 *         Fu Wei <fu.wei@linaro.org>
 *         Hanjun Guo <hanjun.guo@linaro.org>
 */

#include <linux/acpi.h>
#include <linux/init.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>

#include <clocksource/arm_arch_timer.h>

#undef pr_fmt
#define pr_fmt(fmt) "ACPI GTDT: " fmt

/**
 * struct acpi_gtdt_descriptor - Store the key info of GTDT for all functions
 * @gtdt:	The pointer to the struct acpi_table_gtdt of GTDT table.
 * @gtdt_end:	The pointer to the end of GTDT table.
 * @platform_timer:	The pointer to the start of Platform Timer Structure
 *
 * The struct store the key info of GTDT table, it should be initialized by
 * acpi_gtdt_init.
 */
struct acpi_gtdt_descriptor {
	struct acpi_table_gtdt *gtdt;
	void *gtdt_end;
	void *platform_timer;
};

static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata;

static inline void *next_platform_timer(void *platform_timer)
{
	struct acpi_gtdt_header *gh = platform_timer;

	platform_timer += gh->length;
	if (platform_timer < acpi_gtdt_desc.gtdt_end)
		return platform_timer;

	return NULL;
}

#define for_each_platform_timer(_g)				\
	for (_g = acpi_gtdt_desc.platform_timer; _g;	\
	     _g = next_platform_timer(_g))

static inline bool is_timer_block(void *platform_timer)
{
	struct acpi_gtdt_header *gh = platform_timer;

	return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK;
}

static inline bool is_non_secure_watchdog(void *platform_timer)
{
	struct acpi_gtdt_header *gh = platform_timer;
	struct acpi_gtdt_watchdog *wd = platform_timer;

	if (gh->type != ACPI_GTDT_TYPE_WATCHDOG)
		return false;

	return !(wd->timer_flags & ACPI_GTDT_WATCHDOG_SECURE);
}

static int __init map_gt_gsi(u32 interrupt, u32 flags)
{
	int trigger, polarity;

	trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
			: ACPI_LEVEL_SENSITIVE;

	polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
			: ACPI_ACTIVE_HIGH;

	return acpi_register_gsi(NULL, interrupt, trigger, polarity);
}

/**
 * acpi_gtdt_map_ppi() - Map the PPIs of per-cpu arch_timer.
 * @type:	the type of PPI.
 *
 * Note: Secure state is not managed by the kernel on ARM64 systems.
 * So we only handle the non-secure timer PPIs,
 * ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type.
 *
 * Return: the mapped PPI value, 0 if error.
 */
int __init acpi_gtdt_map_ppi(int type)
{
	struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;

	switch (type) {
	case ARCH_TIMER_PHYS_NONSECURE_PPI:
		return map_gt_gsi(gtdt->non_secure_el1_interrupt,
				  gtdt->non_secure_el1_flags);
	case ARCH_TIMER_VIRT_PPI:
		return map_gt_gsi(gtdt->virtual_timer_interrupt,
				  gtdt->virtual_timer_flags);

	case ARCH_TIMER_HYP_PPI:
		return map_gt_gsi(gtdt->non_secure_el2_interrupt,
				  gtdt->non_secure_el2_flags);
	default:
		pr_err("Failed to map timer interrupt: invalid type.\n");
	}

	return 0;
}

/**
 * acpi_gtdt_c3stop() - Got c3stop info from GTDT according to the type of PPI.
 * @type:	the type of PPI.
 *
 * Return: true if the timer HW state is lost when a CPU enters an idle state,
 * false otherwise
 */
bool __init acpi_gtdt_c3stop(int type)
{
	struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;

	switch (type) {
	case ARCH_TIMER_PHYS_NONSECURE_PPI:
		return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);

	case ARCH_TIMER_VIRT_PPI:
		return !(gtdt->virtual_timer_flags & ACPI_GTDT_ALWAYS_ON);

	case ARCH_TIMER_HYP_PPI:
		return !(gtdt->non_secure_el2_flags & ACPI_GTDT_ALWAYS_ON);

	default:
		pr_err("Failed to get c3stop info: invalid type.\n");
	}

	return false;
}

/**
 * acpi_gtdt_init() - Get the info of GTDT table to prepare for further init.
 * @table:			The pointer to GTDT table.
 * @platform_timer_count:	It points to a integer variable which is used
 *				for storing the number of platform timers.
 *				This pointer could be NULL, if the caller
 *				doesn't need this info.
 *
 * Return: 0 if success, -EINVAL if error.
 */
int __init acpi_gtdt_init(struct acpi_table_header *table,
			  int *platform_timer_count)
{
	void *platform_timer;
	struct acpi_table_gtdt *gtdt;

	gtdt = container_of(table, struct acpi_table_gtdt, header);
	acpi_gtdt_desc.gtdt = gtdt;
	acpi_gtdt_desc.gtdt_end = (void *)table + table->length;
	acpi_gtdt_desc.platform_timer = NULL;
	if (platform_timer_count)
		*platform_timer_count = 0;

	if (table->revision < 2) {
		pr_warn("Revision:%d doesn't support Platform Timers.\n",
			table->revision);
		return 0;
	}

	if (!gtdt->platform_timer_count) {
		pr_debug("No Platform Timer.\n");
		return 0;
	}

	platform_timer = (void *)gtdt + gtdt->platform_timer_offset;
	if (platform_timer < (void *)table + sizeof(struct acpi_table_gtdt)) {
		pr_err(FW_BUG "invalid timer data.\n");
		return -EINVAL;
	}
	acpi_gtdt_desc.platform_timer = platform_timer;
	if (platform_timer_count)
		*platform_timer_count = gtdt->platform_timer_count;

	return 0;
}

static int __init gtdt_parse_timer_block(struct acpi_gtdt_timer_block *block,
					 struct arch_timer_mem *timer_mem)
{
	int i;
	struct arch_timer_mem_frame *frame;
	struct acpi_gtdt_timer_entry *gtdt_frame;

	if (!block->timer_count) {
		pr_err(FW_BUG "GT block present, but frame count is zero.\n");
		return -ENODEV;
	}

	if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) {
		pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n",
		       block->timer_count);
		return -EINVAL;
	}

	timer_mem->cntctlbase = (phys_addr_t)block->block_address;
	/*
	 * The CNTCTLBase frame is 4KB (register offsets 0x000 - 0xFFC).
	 * See ARM DDI 0487A.k_iss10775, page I1-5129, Table I1-3
	 * "CNTCTLBase memory map".
	 */
	timer_mem->size = SZ_4K;

	gtdt_frame = (void *)block + block->timer_offset;
	if (gtdt_frame + block->timer_count != (void *)block + block->header.length)
		return -EINVAL;

	/*
	 * Get the GT timer Frame data for every GT Block Timer
	 */
	for (i = 0; i < block->timer_count; i++, gtdt_frame++) {
		if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
			continue;
		if (gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES ||
		    !gtdt_frame->base_address || !gtdt_frame->timer_interrupt)
			goto error;

		frame = &timer_mem->frame[gtdt_frame->frame_number];

		/* duplicate frame */
		if (frame->valid)
			goto error;

		frame->phys_irq = map_gt_gsi(gtdt_frame->timer_interrupt,
					     gtdt_frame->timer_flags);
		if (frame->phys_irq <= 0) {
			pr_warn("failed to map physical timer irq in frame %d.\n",
				gtdt_frame->frame_number);
			goto error;
		}

		if (gtdt_frame->virtual_timer_interrupt) {
			frame->virt_irq =
				map_gt_gsi(gtdt_frame->virtual_timer_interrupt,
					   gtdt_frame->virtual_timer_flags);
			if (frame->virt_irq <= 0) {
				pr_warn("failed to map virtual timer irq in frame %d.\n",
					gtdt_frame->frame_number);
				goto error;
			}
		} else {
			pr_debug("virtual timer in frame %d not implemented.\n",
				 gtdt_frame->frame_number);
		}

		frame->cntbase = gtdt_frame->base_address;
		/*
		 * The CNTBaseN frame is 4KB (register offsets 0x000 - 0xFFC).
		 * See ARM DDI 0487A.k_iss10775, page I1-5130, Table I1-4
		 * "CNTBaseN memory map".
		 */
		frame->size = SZ_4K;
		frame->valid = true;
	}

	return 0;

error:
	do {
		if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER ||
		    gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES)
			continue;

		frame = &timer_mem->frame[gtdt_frame->frame_number];

		if (frame->phys_irq > 0)
			acpi_unregister_gsi(gtdt_frame->timer_interrupt);
		frame->phys_irq = 0;

		if (frame->virt_irq > 0)
			acpi_unregister_gsi(gtdt_frame->virtual_timer_interrupt);
		frame->virt_irq = 0;
	} while (i-- >= 0 && gtdt_frame--);

	return -EINVAL;
}

/**
 * acpi_arch_timer_mem_init() - Get the info of all GT blocks in GTDT table.
 * @timer_mem:	The pointer to the array of struct arch_timer_mem for returning
 *		the result of parsing. The element number of this array should
 *		be platform_timer_count(the total number of platform timers).
 * @timer_count: It points to a integer variable which is used for storing the
 *		number of GT blocks we have parsed.
 *
 * Return: 0 if success, -EINVAL/-ENODEV if error.
 */
int __init acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem,
				    int *timer_count)
{
	int ret;
	void *platform_timer;

	*timer_count = 0;
	for_each_platform_timer(platform_timer) {
		if (is_timer_block(platform_timer)) {
			ret = gtdt_parse_timer_block(platform_timer, timer_mem);
			if (ret)
				return ret;
			timer_mem++;
			(*timer_count)++;
		}
	}

	if (*timer_count)
		pr_info("found %d memory-mapped timer block(s).\n",
			*timer_count);

	return 0;
}

/*
 * Initialize a SBSA generic Watchdog platform device info from GTDT
 */
static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
					int index)
{
	struct platform_device *pdev;
	int irq = map_gt_gsi(wd->timer_interrupt, wd->timer_flags);

	/*
	 * According to SBSA specification the size of refresh and control
	 * frames of SBSA Generic Watchdog is SZ_4K(Offset 0x000 – 0xFFF).
	 */
	struct resource res[] = {
		DEFINE_RES_MEM(wd->control_frame_address, SZ_4K),
		DEFINE_RES_MEM(wd->refresh_frame_address, SZ_4K),
		DEFINE_RES_IRQ(irq),
	};
	int nr_res = ARRAY_SIZE(res);

	pr_debug("found a Watchdog (0x%llx/0x%llx gsi:%u flags:0x%x).\n",
		 wd->refresh_frame_address, wd->control_frame_address,
		 wd->timer_interrupt, wd->timer_flags);

	if (!(wd->refresh_frame_address && wd->control_frame_address)) {
		pr_err(FW_BUG "failed to get the Watchdog base address.\n");
		acpi_unregister_gsi(wd->timer_interrupt);
		return -EINVAL;
	}

	if (irq <= 0) {
		pr_warn("failed to map the Watchdog interrupt.\n");
		nr_res--;
	}

	/*
	 * Add a platform device named "sbsa-gwdt" to match the platform driver.
	 * "sbsa-gwdt": SBSA(Server Base System Architecture) Generic Watchdog
	 * The platform driver can get device info below by matching this name.
	 */
	pdev = platform_device_register_simple("sbsa-gwdt", index, res, nr_res);
	if (IS_ERR(pdev)) {
		acpi_unregister_gsi(wd->timer_interrupt);
		return PTR_ERR(pdev);
	}

	return 0;
}

static int __init gtdt_sbsa_gwdt_init(void)
{
	void *platform_timer;
	struct acpi_table_header *table;
	int ret, timer_count, gwdt_count = 0;

	if (acpi_disabled)
		return 0;

	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_GTDT, 0, &table)))
		return -EINVAL;

	/*
	 * Note: Even though the global variable acpi_gtdt_desc has been
	 * initialized by acpi_gtdt_init() while initializing the arch timers,
	 * when we call this function to get SBSA watchdogs info from GTDT, the
	 * pointers stashed in it are stale (since they are early temporary
	 * mappings carried out before acpi_permanent_mmap is set) and we need
	 * to re-initialize them with permanent mapped pointer values to let the
	 * GTDT parsing possible.
	 */
	ret = acpi_gtdt_init(table, &timer_count);
	if (ret || !timer_count)
		return ret;

	for_each_platform_timer(platform_timer) {
		if (is_non_secure_watchdog(platform_timer)) {
			ret = gtdt_import_sbsa_gwdt(platform_timer, gwdt_count);
			if (ret)
				break;
			gwdt_count++;
		}
	}

	if (gwdt_count)
		pr_info("found %d SBSA generic Watchdog(s).\n", gwdt_count);

	return ret;
}

device_initcall(gtdt_sbsa_gwdt_init);