xref: /openbmc/linux/drivers/irqchip/irq-gic-v2m.c (revision 1c0bd035) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ARM GIC v2m MSI(-X) support
4  * Support for Message Signaled Interrupts for systems that
5  * implement ARM Generic Interrupt Controller: GICv2m.
6  *
7  * Copyright (C) 2014 Advanced Micro Devices, Inc.
8  * Authors: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
9  *	    Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
10  *	    Brandon Anderson <brandon.anderson@amd.com>
11  */
12 
13 #define pr_fmt(fmt) "GICv2m: " fmt
14 
15 #include <linux/acpi.h>
16 #include <linux/dma-iommu.h>
17 #include <linux/irq.h>
18 #include <linux/irqdomain.h>
19 #include <linux/kernel.h>
20 #include <linux/pci.h>
21 #include <linux/msi.h>
22 #include <linux/of_address.h>
23 #include <linux/of_pci.h>
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/irqchip/arm-gic.h>
27 
28 /*
29 * MSI_TYPER:
30 *     [31:26] Reserved
31 *     [25:16] lowest SPI assigned to MSI
32 *     [15:10] Reserved
33 *     [9:0]   Numer of SPIs assigned to MSI
34 */
35 #define V2M_MSI_TYPER		       0x008
36 #define V2M_MSI_TYPER_BASE_SHIFT       16
37 #define V2M_MSI_TYPER_BASE_MASK	       0x3FF
38 #define V2M_MSI_TYPER_NUM_MASK	       0x3FF
39 #define V2M_MSI_SETSPI_NS	       0x040
40 #define V2M_MIN_SPI		       32
41 #define V2M_MAX_SPI		       1019
42 #define V2M_MSI_IIDR		       0xFCC
43 
44 #define V2M_MSI_TYPER_BASE_SPI(x)      \
45 	       (((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)
46 
47 #define V2M_MSI_TYPER_NUM_SPI(x)       ((x) & V2M_MSI_TYPER_NUM_MASK)
48 
49 /* APM X-Gene with GICv2m MSI_IIDR register value */
50 #define XGENE_GICV2M_MSI_IIDR		0x06000170
51 
52 /* Broadcom NS2 GICv2m MSI_IIDR register value */
53 #define BCM_NS2_GICV2M_MSI_IIDR		0x0000013f
54 
55 /* List of flags for specific v2m implementation */
56 #define GICV2M_NEEDS_SPI_OFFSET		0x00000001
57 #define GICV2M_GRAVITON_ADDRESS_ONLY	0x00000002
58 
59 static LIST_HEAD(v2m_nodes);
60 static DEFINE_SPINLOCK(v2m_lock);
61 
62 struct v2m_data {
63 	struct list_head entry;
64 	struct fwnode_handle *fwnode;
65 	struct resource res;	/* GICv2m resource */
66 	void __iomem *base;	/* GICv2m virt address */
67 	u32 spi_start;		/* The SPI number that MSIs start */
68 	u32 nr_spis;		/* The number of SPIs for MSIs */
69 	u32 spi_offset;		/* offset to be subtracted from SPI number */
70 	unsigned long *bm;	/* MSI vector bitmap */
71 	u32 flags;		/* v2m flags for specific implementation */
72 };
73 
74 static void gicv2m_mask_msi_irq(struct irq_data *d)
75 {
76 	pci_msi_mask_irq(d);
77 	irq_chip_mask_parent(d);
78 }
79 
80 static void gicv2m_unmask_msi_irq(struct irq_data *d)
81 {
82 	pci_msi_unmask_irq(d);
83 	irq_chip_unmask_parent(d);
84 }
85 
86 static struct irq_chip gicv2m_msi_irq_chip = {
87 	.name			= "MSI",
88 	.irq_mask		= gicv2m_mask_msi_irq,
89 	.irq_unmask		= gicv2m_unmask_msi_irq,
90 	.irq_eoi		= irq_chip_eoi_parent,
91 };
92 
93 static struct msi_domain_info gicv2m_msi_domain_info = {
94 	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
95 		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
96 	.chip	= &gicv2m_msi_irq_chip,
97 };
98 
99 static phys_addr_t gicv2m_get_msi_addr(struct v2m_data *v2m, int hwirq)
100 {
101 	if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)
102 		return v2m->res.start | ((hwirq - 32) << 3);
103 	else
104 		return v2m->res.start + V2M_MSI_SETSPI_NS;
105 }
106 
107 static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
108 {
109 	struct v2m_data *v2m = irq_data_get_irq_chip_data(data);
110 	phys_addr_t addr = gicv2m_get_msi_addr(v2m, data->hwirq);
111 
112 	msg->address_hi = upper_32_bits(addr);
113 	msg->address_lo = lower_32_bits(addr);
114 
115 	if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)
116 		msg->data = 0;
117 	else
118 		msg->data = data->hwirq;
119 	if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET)
120 		msg->data -= v2m->spi_offset;
121 
122 	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg);
123 }
124 
125 static struct irq_chip gicv2m_irq_chip = {
126 	.name			= "GICv2m",
127 	.irq_mask		= irq_chip_mask_parent,
128 	.irq_unmask		= irq_chip_unmask_parent,
129 	.irq_eoi		= irq_chip_eoi_parent,
130 	.irq_set_affinity	= irq_chip_set_affinity_parent,
131 	.irq_compose_msi_msg	= gicv2m_compose_msi_msg,
132 };
133 
134 static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain,
135 				       unsigned int virq,
136 				       irq_hw_number_t hwirq)
137 {
138 	struct irq_fwspec fwspec;
139 	struct irq_data *d;
140 	int err;
141 
142 	if (is_of_node(domain->parent->fwnode)) {
143 		fwspec.fwnode = domain->parent->fwnode;
144 		fwspec.param_count = 3;
145 		fwspec.param[0] = 0;
146 		fwspec.param[1] = hwirq - 32;
147 		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
148 	} else if (is_fwnode_irqchip(domain->parent->fwnode)) {
149 		fwspec.fwnode = domain->parent->fwnode;
150 		fwspec.param_count = 2;
151 		fwspec.param[0] = hwirq;
152 		fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
153 	} else {
154 		return -EINVAL;
155 	}
156 
157 	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
158 	if (err)
159 		return err;
160 
161 	/* Configure the interrupt line to be edge */
162 	d = irq_domain_get_irq_data(domain->parent, virq);
163 	d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
164 	return 0;
165 }
166 
167 static void gicv2m_unalloc_msi(struct v2m_data *v2m, unsigned int hwirq,
168 			       int nr_irqs)
169 {
170 	spin_lock(&v2m_lock);
171 	bitmap_release_region(v2m->bm, hwirq - v2m->spi_start,
172 			      get_count_order(nr_irqs));
173 	spin_unlock(&v2m_lock);
174 }
175 
176 static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
177 				   unsigned int nr_irqs, void *args)
178 {
179 	msi_alloc_info_t *info = args;
180 	struct v2m_data *v2m = NULL, *tmp;
181 	int hwirq, offset, i, err = 0;
182 
183 	spin_lock(&v2m_lock);
184 	list_for_each_entry(tmp, &v2m_nodes, entry) {
185 		offset = bitmap_find_free_region(tmp->bm, tmp->nr_spis,
186 						 get_count_order(nr_irqs));
187 		if (offset >= 0) {
188 			v2m = tmp;
189 			break;
190 		}
191 	}
192 	spin_unlock(&v2m_lock);
193 
194 	if (!v2m)
195 		return -ENOSPC;
196 
197 	hwirq = v2m->spi_start + offset;
198 
199 	err = iommu_dma_prepare_msi(info->desc,
200 				    gicv2m_get_msi_addr(v2m, hwirq));
201 	if (err)
202 		return err;
203 
204 	for (i = 0; i < nr_irqs; i++) {
205 		err = gicv2m_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
206 		if (err)
207 			goto fail;
208 
209 		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
210 					      &gicv2m_irq_chip, v2m);
211 	}
212 
213 	return 0;
214 
215 fail:
216 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
217 	gicv2m_unalloc_msi(v2m, hwirq, nr_irqs);
218 	return err;
219 }
220 
221 static void gicv2m_irq_domain_free(struct irq_domain *domain,
222 				   unsigned int virq, unsigned int nr_irqs)
223 {
224 	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
225 	struct v2m_data *v2m = irq_data_get_irq_chip_data(d);
226 
227 	gicv2m_unalloc_msi(v2m, d->hwirq, nr_irqs);
228 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
229 }
230 
231 static const struct irq_domain_ops gicv2m_domain_ops = {
232 	.alloc			= gicv2m_irq_domain_alloc,
233 	.free			= gicv2m_irq_domain_free,
234 };
235 
236 static bool is_msi_spi_valid(u32 base, u32 num)
237 {
238 	if (base < V2M_MIN_SPI) {
239 		pr_err("Invalid MSI base SPI (base:%u)\n", base);
240 		return false;
241 	}
242 
243 	if ((num == 0) || (base + num > V2M_MAX_SPI)) {
244 		pr_err("Number of SPIs (%u) exceed maximum (%u)\n",
245 		       num, V2M_MAX_SPI - V2M_MIN_SPI + 1);
246 		return false;
247 	}
248 
249 	return true;
250 }
251 
252 static struct irq_chip gicv2m_pmsi_irq_chip = {
253 	.name			= "pMSI",
254 };
255 
256 static struct msi_domain_ops gicv2m_pmsi_ops = {
257 };
258 
259 static struct msi_domain_info gicv2m_pmsi_domain_info = {
260 	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
261 	.ops	= &gicv2m_pmsi_ops,
262 	.chip	= &gicv2m_pmsi_irq_chip,
263 };
264 
265 static void gicv2m_teardown(void)
266 {
267 	struct v2m_data *v2m, *tmp;
268 
269 	list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) {
270 		list_del(&v2m->entry);
271 		bitmap_free(v2m->bm);
272 		iounmap(v2m->base);
273 		of_node_put(to_of_node(v2m->fwnode));
274 		if (is_fwnode_irqchip(v2m->fwnode))
275 			irq_domain_free_fwnode(v2m->fwnode);
276 		kfree(v2m);
277 	}
278 }
279 
280 static int gicv2m_allocate_domains(struct irq_domain *parent)
281 {
282 	struct irq_domain *inner_domain, *pci_domain, *plat_domain;
283 	struct v2m_data *v2m;
284 
285 	v2m = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
286 	if (!v2m)
287 		return 0;
288 
289 	inner_domain = irq_domain_create_tree(v2m->fwnode,
290 					      &gicv2m_domain_ops, v2m);
291 	if (!inner_domain) {
292 		pr_err("Failed to create GICv2m domain\n");
293 		return -ENOMEM;
294 	}
295 
296 	irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
297 	inner_domain->parent = parent;
298 	pci_domain = pci_msi_create_irq_domain(v2m->fwnode,
299 					       &gicv2m_msi_domain_info,
300 					       inner_domain);
301 	plat_domain = platform_msi_create_irq_domain(v2m->fwnode,
302 						     &gicv2m_pmsi_domain_info,
303 						     inner_domain);
304 	if (!pci_domain || !plat_domain) {
305 		pr_err("Failed to create MSI domains\n");
306 		if (plat_domain)
307 			irq_domain_remove(plat_domain);
308 		if (pci_domain)
309 			irq_domain_remove(pci_domain);
310 		irq_domain_remove(inner_domain);
311 		return -ENOMEM;
312 	}
313 
314 	return 0;
315 }
316 
317 static int __init gicv2m_init_one(struct fwnode_handle *fwnode,
318 				  u32 spi_start, u32 nr_spis,
319 				  struct resource *res, u32 flags)
320 {
321 	int ret;
322 	struct v2m_data *v2m;
323 
324 	v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
325 	if (!v2m)
326 		return -ENOMEM;
327 
328 	INIT_LIST_HEAD(&v2m->entry);
329 	v2m->fwnode = fwnode;
330 	v2m->flags = flags;
331 
332 	memcpy(&v2m->res, res, sizeof(struct resource));
333 
334 	v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
335 	if (!v2m->base) {
336 		pr_err("Failed to map GICv2m resource\n");
337 		ret = -ENOMEM;
338 		goto err_free_v2m;
339 	}
340 
341 	if (spi_start && nr_spis) {
342 		v2m->spi_start = spi_start;
343 		v2m->nr_spis = nr_spis;
344 	} else {
345 		u32 typer;
346 
347 		/* Graviton should always have explicit spi_start/nr_spis */
348 		if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY) {
349 			ret = -EINVAL;
350 			goto err_iounmap;
351 		}
352 		typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);
353 
354 		v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
355 		v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
356 	}
357 
358 	if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
359 		ret = -EINVAL;
360 		goto err_iounmap;
361 	}
362 
363 	/*
364 	 * APM X-Gene GICv2m implementation has an erratum where
365 	 * the MSI data needs to be the offset from the spi_start
366 	 * in order to trigger the correct MSI interrupt. This is
367 	 * different from the standard GICv2m implementation where
368 	 * the MSI data is the absolute value within the range from
369 	 * spi_start to (spi_start + num_spis).
370 	 *
371 	 * Broadcom NS2 GICv2m implementation has an erratum where the MSI data
372 	 * is 'spi_number - 32'
373 	 *
374 	 * Reading that register fails on the Graviton implementation
375 	 */
376 	if (!(v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)) {
377 		switch (readl_relaxed(v2m->base + V2M_MSI_IIDR)) {
378 		case XGENE_GICV2M_MSI_IIDR:
379 			v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
380 			v2m->spi_offset = v2m->spi_start;
381 			break;
382 		case BCM_NS2_GICV2M_MSI_IIDR:
383 			v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
384 			v2m->spi_offset = 32;
385 			break;
386 		}
387 	}
388 	v2m->bm = bitmap_zalloc(v2m->nr_spis, GFP_KERNEL);
389 	if (!v2m->bm) {
390 		ret = -ENOMEM;
391 		goto err_iounmap;
392 	}
393 
394 	list_add_tail(&v2m->entry, &v2m_nodes);
395 
396 	pr_info("range%pR, SPI[%d:%d]\n", res,
397 		v2m->spi_start, (v2m->spi_start + v2m->nr_spis - 1));
398 	return 0;
399 
400 err_iounmap:
401 	iounmap(v2m->base);
402 err_free_v2m:
403 	kfree(v2m);
404 	return ret;
405 }
406 
407 static const struct of_device_id gicv2m_device_id[] = {
408 	{	.compatible	= "arm,gic-v2m-frame",	},
409 	{},
410 };
411 
412 static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
413 				 struct irq_domain *parent)
414 {
415 	int ret = 0;
416 	struct device_node *node = to_of_node(parent_handle);
417 	struct device_node *child;
418 
419 	for (child = of_find_matching_node(node, gicv2m_device_id); child;
420 	     child = of_find_matching_node(child, gicv2m_device_id)) {
421 		u32 spi_start = 0, nr_spis = 0;
422 		struct resource res;
423 
424 		if (!of_find_property(child, "msi-controller", NULL))
425 			continue;
426 
427 		ret = of_address_to_resource(child, 0, &res);
428 		if (ret) {
429 			pr_err("Failed to allocate v2m resource.\n");
430 			break;
431 		}
432 
433 		if (!of_property_read_u32(child, "arm,msi-base-spi",
434 					  &spi_start) &&
435 		    !of_property_read_u32(child, "arm,msi-num-spis", &nr_spis))
436 			pr_info("DT overriding V2M MSI_TYPER (base:%u, num:%u)\n",
437 				spi_start, nr_spis);
438 
439 		ret = gicv2m_init_one(&child->fwnode, spi_start, nr_spis,
440 				      &res, 0);
441 		if (ret) {
442 			of_node_put(child);
443 			break;
444 		}
445 	}
446 
447 	if (!ret)
448 		ret = gicv2m_allocate_domains(parent);
449 	if (ret)
450 		gicv2m_teardown();
451 	return ret;
452 }
453 
454 #ifdef CONFIG_ACPI
455 static int acpi_num_msi;
456 
457 static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
458 {
459 	struct v2m_data *data;
460 
461 	if (WARN_ON(acpi_num_msi <= 0))
462 		return NULL;
463 
464 	/* We only return the fwnode of the first MSI frame. */
465 	data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
466 	if (!data)
467 		return NULL;
468 
469 	return data->fwnode;
470 }
471 
472 static bool acpi_check_amazon_graviton_quirks(void)
473 {
474 	static struct acpi_table_madt *madt;
475 	acpi_status status;
476 	bool rc = false;
477 
478 #define ACPI_AMZN_OEM_ID		"AMAZON"
479 
480 	status = acpi_get_table(ACPI_SIG_MADT, 0,
481 				(struct acpi_table_header **)&madt);
482 
483 	if (ACPI_FAILURE(status) || !madt)
484 		return rc;
485 	rc = !memcmp(madt->header.oem_id, ACPI_AMZN_OEM_ID, ACPI_OEM_ID_SIZE);
486 	acpi_put_table((struct acpi_table_header *)madt);
487 
488 	return rc;
489 }
490 
491 static int __init
492 acpi_parse_madt_msi(union acpi_subtable_headers *header,
493 		    const unsigned long end)
494 {
495 	int ret;
496 	struct resource res;
497 	u32 spi_start = 0, nr_spis = 0;
498 	struct acpi_madt_generic_msi_frame *m;
499 	struct fwnode_handle *fwnode;
500 	u32 flags = 0;
501 
502 	m = (struct acpi_madt_generic_msi_frame *)header;
503 	if (BAD_MADT_ENTRY(m, end))
504 		return -EINVAL;
505 
506 	res.start = m->base_address;
507 	res.end = m->base_address + SZ_4K - 1;
508 	res.flags = IORESOURCE_MEM;
509 
510 	if (acpi_check_amazon_graviton_quirks()) {
511 		pr_info("applying Amazon Graviton quirk\n");
512 		res.end = res.start + SZ_8K - 1;
513 		flags |= GICV2M_GRAVITON_ADDRESS_ONLY;
514 		gicv2m_msi_domain_info.flags &= ~MSI_FLAG_MULTI_PCI_MSI;
515 	}
516 
517 	if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
518 		spi_start = m->spi_base;
519 		nr_spis = m->spi_count;
520 
521 		pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
522 			spi_start, nr_spis);
523 	}
524 
525 	fwnode = irq_domain_alloc_fwnode(&res.start);
526 	if (!fwnode) {
527 		pr_err("Unable to allocate GICv2m domain token\n");
528 		return -EINVAL;
529 	}
530 
531 	ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res, flags);
532 	if (ret)
533 		irq_domain_free_fwnode(fwnode);
534 
535 	return ret;
536 }
537 
538 static int __init gicv2m_acpi_init(struct irq_domain *parent)
539 {
540 	int ret;
541 
542 	if (acpi_num_msi > 0)
543 		return 0;
544 
545 	acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
546 				      acpi_parse_madt_msi, 0);
547 
548 	if (acpi_num_msi <= 0)
549 		goto err_out;
550 
551 	ret = gicv2m_allocate_domains(parent);
552 	if (ret)
553 		goto err_out;
554 
555 	pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);
556 
557 	return 0;
558 
559 err_out:
560 	gicv2m_teardown();
561 	return -EINVAL;
562 }
563 #else /* CONFIG_ACPI */
564 static int __init gicv2m_acpi_init(struct irq_domain *parent)
565 {
566 	return -EINVAL;
567 }
568 #endif /* CONFIG_ACPI */
569 
570 int __init gicv2m_init(struct fwnode_handle *parent_handle,
571 		       struct irq_domain *parent)
572 {
573 	if (is_of_node(parent_handle))
574 		return gicv2m_of_init(parent_handle, parent);
575 
576 	return gicv2m_acpi_init(parent);
577 }
578