summaryrefslogtreecommitdiffstats
path: root/drivers/irqchip/irq-gic-v2m.c
blob: 9349fc68b81a96ce8e70dd312ed61b22111f1b29 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ARM GIC v2m MSI(-X) support
 * Support for Message Signaled Interrupts for systems that
 * implement ARM Generic Interrupt Controller: GICv2m.
 *
 * Copyright (C) 2014 Advanced Micro Devices, Inc.
 * Authors: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
 *	    Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
 *	    Brandon Anderson <brandon.anderson@amd.com>
 */

#define pr_fmt(fmt) "GICv2m: " fmt

#include <linux/acpi.h>
#include <linux/dma-iommu.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/irqchip/arm-gic.h>

/*
* MSI_TYPER:
*     [31:26] Reserved
*     [25:16] lowest SPI assigned to MSI
*     [15:10] Reserved
*     [9:0]   Numer of SPIs assigned to MSI
*/
#define V2M_MSI_TYPER		       0x008
#define V2M_MSI_TYPER_BASE_SHIFT       16
#define V2M_MSI_TYPER_BASE_MASK	       0x3FF
#define V2M_MSI_TYPER_NUM_MASK	       0x3FF
#define V2M_MSI_SETSPI_NS	       0x040
#define V2M_MIN_SPI		       32
#define V2M_MAX_SPI		       1019
#define V2M_MSI_IIDR		       0xFCC

#define V2M_MSI_TYPER_BASE_SPI(x)      \
	       (((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)

#define V2M_MSI_TYPER_NUM_SPI(x)       ((x) & V2M_MSI_TYPER_NUM_MASK)

/* APM X-Gene with GICv2m MSI_IIDR register value */
#define XGENE_GICV2M_MSI_IIDR		0x06000170

/* Broadcom NS2 GICv2m MSI_IIDR register value */
#define BCM_NS2_GICV2M_MSI_IIDR		0x0000013f

/* List of flags for specific v2m implementation */
#define GICV2M_NEEDS_SPI_OFFSET		0x00000001
#define GICV2M_GRAVITON_ADDRESS_ONLY	0x00000002

static LIST_HEAD(v2m_nodes);
static DEFINE_SPINLOCK(v2m_lock);

struct v2m_data {
	struct list_head entry;
	struct fwnode_handle *fwnode;
	struct resource res;	/* GICv2m resource */
	void __iomem *base;	/* GICv2m virt address */
	u32 spi_start;		/* The SPI number that MSIs start */
	u32 nr_spis;		/* The number of SPIs for MSIs */
	u32 spi_offset;		/* offset to be subtracted from SPI number */
	unsigned long *bm;	/* MSI vector bitmap */
	u32 flags;		/* v2m flags for specific implementation */
};

static void gicv2m_mask_msi_irq(struct irq_data *d)
{
	pci_msi_mask_irq(d);
	irq_chip_mask_parent(d);
}

static void gicv2m_unmask_msi_irq(struct irq_data *d)
{
	pci_msi_unmask_irq(d);
	irq_chip_unmask_parent(d);
}

static struct irq_chip gicv2m_msi_irq_chip = {
	.name			= "MSI",
	.irq_mask		= gicv2m_mask_msi_irq,
	.irq_unmask		= gicv2m_unmask_msi_irq,
	.irq_eoi		= irq_chip_eoi_parent,
	.irq_write_msi_msg	= pci_msi_domain_write_msg,
};

static struct msi_domain_info gicv2m_msi_domain_info = {
	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
	.chip	= &gicv2m_msi_irq_chip,
};

static phys_addr_t gicv2m_get_msi_addr(struct v2m_data *v2m, int hwirq)
{
	if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)
		return v2m->res.start | ((hwirq - 32) << 3);
	else
		return v2m->res.start + V2M_MSI_SETSPI_NS;
}

static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
{
	struct v2m_data *v2m = irq_data_get_irq_chip_data(data);
	phys_addr_t addr = gicv2m_get_msi_addr(v2m, data->hwirq);

	msg->address_hi = upper_32_bits(addr);
	msg->address_lo = lower_32_bits(addr);

	if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)
		msg->data = 0;
	else
		msg->data = data->hwirq;
	if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET)
		msg->data -= v2m->spi_offset;

	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg);
}

static struct irq_chip gicv2m_irq_chip = {
	.name			= "GICv2m",
	.irq_mask		= irq_chip_mask_parent,
	.irq_unmask		= irq_chip_unmask_parent,
	.irq_eoi		= irq_chip_eoi_parent,
	.irq_set_affinity	= irq_chip_set_affinity_parent,
	.irq_compose_msi_msg	= gicv2m_compose_msi_msg,
};

static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain,
				       unsigned int virq,
				       irq_hw_number_t hwirq)
{
	struct irq_fwspec fwspec;
	struct irq_data *d;
	int err;

	if (is_of_node(domain->parent->fwnode)) {
		fwspec.fwnode = domain->parent->fwnode;
		fwspec.param_count = 3;
		fwspec.param[0] = 0;
		fwspec.param[1] = hwirq - 32;
		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
	} else if (is_fwnode_irqchip(domain->parent->fwnode)) {
		fwspec.fwnode = domain->parent->fwnode;
		fwspec.param_count = 2;
		fwspec.param[0] = hwirq;
		fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
	} else {
		return -EINVAL;
	}

	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
	if (err)
		return err;

	/* Configure the interrupt line to be edge */
	d = irq_domain_get_irq_data(domain->parent, virq);
	d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
	return 0;
}

static void gicv2m_unalloc_msi(struct v2m_data *v2m, unsigned int hwirq,
			       int nr_irqs)
{
	spin_lock(&v2m_lock);
	bitmap_release_region(v2m->bm, hwirq - v2m->spi_start,
			      get_count_order(nr_irqs));
	spin_unlock(&v2m_lock);
}

static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
				   unsigned int nr_irqs, void *args)
{
	msi_alloc_info_t *info = args;
	struct v2m_data *v2m = NULL, *tmp;
	int hwirq, offset, i, err = 0;

	spin_lock(&v2m_lock);
	list_for_each_entry(tmp, &v2m_nodes, entry) {
		offset = bitmap_find_free_region(tmp->bm, tmp->nr_spis,
						 get_count_order(nr_irqs));
		if (offset >= 0) {
			v2m = tmp;
			break;
		}
	}
	spin_unlock(&v2m_lock);

	if (!v2m)
		return -ENOSPC;

	hwirq = v2m->spi_start + offset;

	err = iommu_dma_prepare_msi(info->desc,
				    gicv2m_get_msi_addr(v2m, hwirq));
	if (err)
		return err;

	for (i = 0; i < nr_irqs; i++) {
		err = gicv2m_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
		if (err)
			goto fail;

		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
					      &gicv2m_irq_chip, v2m);
	}

	return 0;

fail:
	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
	gicv2m_unalloc_msi(v2m, hwirq, nr_irqs);
	return err;
}

static void gicv2m_irq_domain_free(struct irq_domain *domain,
				   unsigned int virq, unsigned int nr_irqs)
{
	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
	struct v2m_data *v2m = irq_data_get_irq_chip_data(d);

	gicv2m_unalloc_msi(v2m, d->hwirq, nr_irqs);
	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
}

static const struct irq_domain_ops gicv2m_domain_ops = {
	.alloc			= gicv2m_irq_domain_alloc,
	.free			= gicv2m_irq_domain_free,
};

static bool is_msi_spi_valid(u32 base, u32 num)
{
	if (base < V2M_MIN_SPI) {
		pr_err("Invalid MSI base SPI (base:%u)\n", base);
		return false;
	}

	if ((num == 0) || (base + num > V2M_MAX_SPI)) {
		pr_err("Number of SPIs (%u) exceed maximum (%u)\n",
		       num, V2M_MAX_SPI - V2M_MIN_SPI + 1);
		return false;
	}

	return true;
}

static struct irq_chip gicv2m_pmsi_irq_chip = {
	.name			= "pMSI",
};

static struct msi_domain_ops gicv2m_pmsi_ops = {
};

static struct msi_domain_info gicv2m_pmsi_domain_info = {
	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
	.ops	= &gicv2m_pmsi_ops,
	.chip	= &gicv2m_pmsi_irq_chip,
};

static void gicv2m_teardown(void)
{
	struct v2m_data *v2m, *tmp;

	list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) {
		list_del(&v2m->entry);
		bitmap_free(v2m->bm);
		iounmap(v2m->base);
		of_node_put(to_of_node(v2m->fwnode));
		if (is_fwnode_irqchip(v2m->fwnode))
			irq_domain_free_fwnode(v2m->fwnode);
		kfree(v2m);
	}
}

static int gicv2m_allocate_domains(struct irq_domain *parent)
{
	struct irq_domain *inner_domain, *pci_domain, *plat_domain;
	struct v2m_data *v2m;

	v2m = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
	if (!v2m)
		return 0;

	inner_domain = irq_domain_create_tree(v2m->fwnode,
					      &gicv2m_domain_ops, v2m);
	if (!inner_domain) {
		pr_err("Failed to create GICv2m domain\n");
		return -ENOMEM;
	}

	irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
	inner_domain->parent = parent;
	pci_domain = pci_msi_create_irq_domain(v2m->fwnode,
					       &gicv2m_msi_domain_info,
					       inner_domain);
	plat_domain = platform_msi_create_irq_domain(v2m->fwnode,
						     &gicv2m_pmsi_domain_info,
						     inner_domain);
	if (!pci_domain || !plat_domain) {
		pr_err("Failed to create MSI domains\n");
		if (plat_domain)
			irq_domain_remove(plat_domain);
		if (pci_domain)
			irq_domain_remove(pci_domain);
		irq_domain_remove(inner_domain);
		return -ENOMEM;
	}

	return 0;
}

static int __init gicv2m_init_one(struct fwnode_handle *fwnode,
				  u32 spi_start, u32 nr_spis,
				  struct resource *res, u32 flags)
{
	int ret;
	struct v2m_data *v2m;

	v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
	if (!v2m)
		return -ENOMEM;

	INIT_LIST_HEAD(&v2m->entry);
	v2m->fwnode = fwnode;
	v2m->flags = flags;

	memcpy(&v2m->res, res, sizeof(struct resource));

	v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
	if (!v2m->base) {
		pr_err("Failed to map GICv2m resource\n");
		ret = -ENOMEM;
		goto err_free_v2m;
	}

	if (spi_start && nr_spis) {
		v2m->spi_start = spi_start;
		v2m->nr_spis = nr_spis;
	} else {
		u32 typer;

		/* Graviton should always have explicit spi_start/nr_spis */
		if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY) {
			ret = -EINVAL;
			goto err_iounmap;
		}
		typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);

		v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
		v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
	}

	if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
		ret = -EINVAL;
		goto err_iounmap;
	}

	/*
	 * APM X-Gene GICv2m implementation has an erratum where
	 * the MSI data needs to be the offset from the spi_start
	 * in order to trigger the correct MSI interrupt. This is
	 * different from the standard GICv2m implementation where
	 * the MSI data is the absolute value within the range from
	 * spi_start to (spi_start + num_spis).
	 *
	 * Broadcom NS2 GICv2m implementation has an erratum where the MSI data
	 * is 'spi_number - 32'
	 *
	 * Reading that register fails on the Graviton implementation
	 */
	if (!(v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)) {
		switch (readl_relaxed(v2m->base + V2M_MSI_IIDR)) {
		case XGENE_GICV2M_MSI_IIDR:
			v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
			v2m->spi_offset = v2m->spi_start;
			break;
		case BCM_NS2_GICV2M_MSI_IIDR:
			v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
			v2m->spi_offset = 32;
			break;
		}
	}
	v2m->bm = bitmap_zalloc(v2m->nr_spis, GFP_KERNEL);
	if (!v2m->bm) {
		ret = -ENOMEM;
		goto err_iounmap;
	}

	list_add_tail(&v2m->entry, &v2m_nodes);

	pr_info("range%pR, SPI[%d:%d]\n", res,
		v2m->spi_start, (v2m->spi_start + v2m->nr_spis - 1));
	return 0;

err_iounmap:
	iounmap(v2m->base);
err_free_v2m:
	kfree(v2m);
	return ret;
}

static struct of_device_id gicv2m_device_id[] = {
	{	.compatible	= "arm,gic-v2m-frame",	},
	{},
};

static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
				 struct irq_domain *parent)
{
	int ret = 0;
	struct device_node *node = to_of_node(parent_handle);
	struct device_node *child;

	for (child = of_find_matching_node(node, gicv2m_device_id); child;
	     child = of_find_matching_node(child, gicv2m_device_id)) {
		u32 spi_start = 0, nr_spis = 0;
		struct resource res;

		if (!of_find_property(child, "msi-controller", NULL))
			continue;

		ret = of_address_to_resource(child, 0, &res);
		if (ret) {
			pr_err("Failed to allocate v2m resource.\n");
			break;
		}

		if (!of_property_read_u32(child, "arm,msi-base-spi",
					  &spi_start) &&
		    !of_property_read_u32(child, "arm,msi-num-spis", &nr_spis))
			pr_info("DT overriding V2M MSI_TYPER (base:%u, num:%u)\n",
				spi_start, nr_spis);

		ret = gicv2m_init_one(&child->fwnode, spi_start, nr_spis,
				      &res, 0);
		if (ret) {
			of_node_put(child);
			break;
		}
	}

	if (!ret)
		ret = gicv2m_allocate_domains(parent);
	if (ret)
		gicv2m_teardown();
	return ret;
}

#ifdef CONFIG_ACPI
static int acpi_num_msi;

static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
{
	struct v2m_data *data;

	if (WARN_ON(acpi_num_msi <= 0))
		return NULL;

	/* We only return the fwnode of the first MSI frame. */
	data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
	if (!data)
		return NULL;

	return data->fwnode;
}

static bool acpi_check_amazon_graviton_quirks(void)
{
	static struct acpi_table_madt *madt;
	acpi_status status;
	bool rc = false;

#define ACPI_AMZN_OEM_ID		"AMAZON"

	status = acpi_get_table(ACPI_SIG_MADT, 0,
				(struct acpi_table_header **)&madt);

	if (ACPI_FAILURE(status) || !madt)
		return rc;
	rc = !memcmp(madt->header.oem_id, ACPI_AMZN_OEM_ID, ACPI_OEM_ID_SIZE);
	acpi_put_table((struct acpi_table_header *)madt);

	return rc;
}

static int __init
acpi_parse_madt_msi(union acpi_subtable_headers *header,
		    const unsigned long end)
{
	int ret;
	struct resource res;
	u32 spi_start = 0, nr_spis = 0;
	struct acpi_madt_generic_msi_frame *m;
	struct fwnode_handle *fwnode;
	u32 flags = 0;

	m = (struct acpi_madt_generic_msi_frame *)header;
	if (BAD_MADT_ENTRY(m, end))
		return -EINVAL;

	res.start = m->base_address;
	res.end = m->base_address + SZ_4K - 1;
	res.flags = IORESOURCE_MEM;

	if (acpi_check_amazon_graviton_quirks()) {
		pr_info("applying Amazon Graviton quirk\n");
		res.end = res.start + SZ_8K - 1;
		flags |= GICV2M_GRAVITON_ADDRESS_ONLY;
		gicv2m_msi_domain_info.flags &= ~MSI_FLAG_MULTI_PCI_MSI;
	}

	if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
		spi_start = m->spi_base;
		nr_spis = m->spi_count;

		pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
			spi_start, nr_spis);
	}

	fwnode = irq_domain_alloc_fwnode(&res.start);
	if (!fwnode) {
		pr_err("Unable to allocate GICv2m domain token\n");
		return -EINVAL;
	}

	ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res, flags);
	if (ret)
		irq_domain_free_fwnode(fwnode);

	return ret;
}

static int __init gicv2m_acpi_init(struct irq_domain *parent)
{
	int ret;

	if (acpi_num_msi > 0)
		return 0;

	acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
				      acpi_parse_madt_msi, 0);

	if (acpi_num_msi <= 0)
		goto err_out;

	ret = gicv2m_allocate_domains(parent);
	if (ret)
		goto err_out;

	pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);

	return 0;

err_out:
	gicv2m_teardown();
	return -EINVAL;
}
#else /* CONFIG_ACPI */
static int __init gicv2m_acpi_init(struct irq_domain *parent)
{
	return -EINVAL;
}
#endif /* CONFIG_ACPI */

int __init gicv2m_init(struct fwnode_handle *parent_handle,
		       struct irq_domain *parent)
{
	if (is_of_node(parent_handle))
		return gicv2m_of_init(parent_handle, parent);

	return gicv2m_acpi_init(parent);
}