xref: /openbmc/linux/drivers/irqchip/irq-gic-v2m.c (revision 0bf49ffb) 
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 	.irq_write_msi_msg	= pci_msi_domain_write_msg,
92 };
93 
94 static struct msi_domain_info gicv2m_msi_domain_info = {
95 	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
96 		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
97 	.chip	= &gicv2m_msi_irq_chip,
98 };
99 
100 static phys_addr_t gicv2m_get_msi_addr(struct v2m_data *v2m, int hwirq)
101 {
102 	if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)
103 		return v2m->res.start | ((hwirq - 32) << 3);
104 	else
105 		return v2m->res.start + V2M_MSI_SETSPI_NS;
106 }
107 
108 static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
109 {
110 	struct v2m_data *v2m = irq_data_get_irq_chip_data(data);
111 	phys_addr_t addr = gicv2m_get_msi_addr(v2m, data->hwirq);
112 
113 	msg->address_hi = upper_32_bits(addr);
114 	msg->address_lo = lower_32_bits(addr);
115 
116 	if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)
117 		msg->data = 0;
118 	else
119 		msg->data = data->hwirq;
120 	if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET)
121 		msg->data -= v2m->spi_offset;
122 
123 	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg);
124 }
125 
126 static struct irq_chip gicv2m_irq_chip = {
127 	.name			= "GICv2m",
128 	.irq_mask		= irq_chip_mask_parent,
129 	.irq_unmask		= irq_chip_unmask_parent,
130 	.irq_eoi		= irq_chip_eoi_parent,
131 	.irq_set_affinity	= irq_chip_set_affinity_parent,
132 	.irq_compose_msi_msg	= gicv2m_compose_msi_msg,
133 };
134 
135 static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain,
136 				       unsigned int virq,
137 				       irq_hw_number_t hwirq)
138 {
139 	struct irq_fwspec fwspec;
140 	struct irq_data *d;
141 	int err;
142 
143 	if (is_of_node(domain->parent->fwnode)) {
144 		fwspec.fwnode = domain->parent->fwnode;
145 		fwspec.param_count = 3;
146 		fwspec.param[0] = 0;
147 		fwspec.param[1] = hwirq - 32;
148 		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
149 	} else if (is_fwnode_irqchip(domain->parent->fwnode)) {
150 		fwspec.fwnode = domain->parent->fwnode;
151 		fwspec.param_count = 2;
152 		fwspec.param[0] = hwirq;
153 		fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
154 	} else {
155 		return -EINVAL;
156 	}
157 
158 	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
159 	if (err)
160 		return err;
161 
162 	/* Configure the interrupt line to be edge */
163 	d = irq_domain_get_irq_data(domain->parent, virq);
164 	d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
165 	return 0;
166 }
167 
168 static void gicv2m_unalloc_msi(struct v2m_data *v2m, unsigned int hwirq,
169 			       int nr_irqs)
170 {
171 	spin_lock(&v2m_lock);
172 	bitmap_release_region(v2m->bm, hwirq - v2m->spi_start,
173 			      get_count_order(nr_irqs));
174 	spin_unlock(&v2m_lock);
175 }
176 
177 static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
178 				   unsigned int nr_irqs, void *args)
179 {
180 	msi_alloc_info_t *info = args;
181 	struct v2m_data *v2m = NULL, *tmp;
182 	int hwirq, offset, i, err = 0;
183 
184 	spin_lock(&v2m_lock);
185 	list_for_each_entry(tmp, &v2m_nodes, entry) {
186 		offset = bitmap_find_free_region(tmp->bm, tmp->nr_spis,
187 						 get_count_order(nr_irqs));
188 		if (offset >= 0) {
189 			v2m = tmp;
190 			break;
191 		}
192 	}
193 	spin_unlock(&v2m_lock);
194 
195 	if (!v2m)
196 		return -ENOSPC;
197 
198 	hwirq = v2m->spi_start + offset;
199 
200 	err = iommu_dma_prepare_msi(info->desc,
201 				    gicv2m_get_msi_addr(v2m, hwirq));
202 	if (err)
203 		return err;
204 
205 	for (i = 0; i < nr_irqs; i++) {
206 		err = gicv2m_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
207 		if (err)
208 			goto fail;
209 
210 		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
211 					      &gicv2m_irq_chip, v2m);
212 	}
213 
214 	return 0;
215 
216 fail:
217 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
218 	gicv2m_unalloc_msi(v2m, hwirq, nr_irqs);
219 	return err;
220 }
221 
222 static void gicv2m_irq_domain_free(struct irq_domain *domain,
223 				   unsigned int virq, unsigned int nr_irqs)
224 {
225 	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
226 	struct v2m_data *v2m = irq_data_get_irq_chip_data(d);
227 
228 	gicv2m_unalloc_msi(v2m, d->hwirq, nr_irqs);
229 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
230 }
231 
232 static const struct irq_domain_ops gicv2m_domain_ops = {
233 	.alloc			= gicv2m_irq_domain_alloc,
234 	.free			= gicv2m_irq_domain_free,
235 };
236 
237 static bool is_msi_spi_valid(u32 base, u32 num)
238 {
239 	if (base < V2M_MIN_SPI) {
240 		pr_err("Invalid MSI base SPI (base:%u)\n", base);
241 		return false;
242 	}
243 
244 	if ((num == 0) || (base + num > V2M_MAX_SPI)) {
245 		pr_err("Number of SPIs (%u) exceed maximum (%u)\n",
246 		       num, V2M_MAX_SPI - V2M_MIN_SPI + 1);
247 		return false;
248 	}
249 
250 	return true;
251 }
252 
253 static struct irq_chip gicv2m_pmsi_irq_chip = {
254 	.name			= "pMSI",
255 };
256 
257 static struct msi_domain_ops gicv2m_pmsi_ops = {
258 };
259 
260 static struct msi_domain_info gicv2m_pmsi_domain_info = {
261 	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
262 	.ops	= &gicv2m_pmsi_ops,
263 	.chip	= &gicv2m_pmsi_irq_chip,
264 };
265 
266 static void gicv2m_teardown(void)
267 {
268 	struct v2m_data *v2m, *tmp;
269 
270 	list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) {
271 		list_del(&v2m->entry);
272 		kfree(v2m->bm);
273 		iounmap(v2m->base);
274 		of_node_put(to_of_node(v2m->fwnode));
275 		if (is_fwnode_irqchip(v2m->fwnode))
276 			irq_domain_free_fwnode(v2m->fwnode);
277 		kfree(v2m);
278 	}
279 }
280 
281 static int gicv2m_allocate_domains(struct irq_domain *parent)
282 {
283 	struct irq_domain *inner_domain, *pci_domain, *plat_domain;
284 	struct v2m_data *v2m;
285 
286 	v2m = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
287 	if (!v2m)
288 		return 0;
289 
290 	inner_domain = irq_domain_create_tree(v2m->fwnode,
291 					      &gicv2m_domain_ops, v2m);
292 	if (!inner_domain) {
293 		pr_err("Failed to create GICv2m domain\n");
294 		return -ENOMEM;
295 	}
296 
297 	irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
298 	inner_domain->parent = parent;
299 	pci_domain = pci_msi_create_irq_domain(v2m->fwnode,
300 					       &gicv2m_msi_domain_info,
301 					       inner_domain);
302 	plat_domain = platform_msi_create_irq_domain(v2m->fwnode,
303 						     &gicv2m_pmsi_domain_info,
304 						     inner_domain);
305 	if (!pci_domain || !plat_domain) {
306 		pr_err("Failed to create MSI domains\n");
307 		if (plat_domain)
308 			irq_domain_remove(plat_domain);
309 		if (pci_domain)
310 			irq_domain_remove(pci_domain);
311 		irq_domain_remove(inner_domain);
312 		return -ENOMEM;
313 	}
314 
315 	return 0;
316 }
317 
318 static int __init gicv2m_init_one(struct fwnode_handle *fwnode,
319 				  u32 spi_start, u32 nr_spis,
320 				  struct resource *res, u32 flags)
321 {
322 	int ret;
323 	struct v2m_data *v2m;
324 
325 	v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
326 	if (!v2m) {
327 		pr_err("Failed to allocate struct v2m_data.\n");
328 		return -ENOMEM;
329 	}
330 
331 	INIT_LIST_HEAD(&v2m->entry);
332 	v2m->fwnode = fwnode;
333 	v2m->flags = flags;
334 
335 	memcpy(&v2m->res, res, sizeof(struct resource));
336 
337 	v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
338 	if (!v2m->base) {
339 		pr_err("Failed to map GICv2m resource\n");
340 		ret = -ENOMEM;
341 		goto err_free_v2m;
342 	}
343 
344 	if (spi_start && nr_spis) {
345 		v2m->spi_start = spi_start;
346 		v2m->nr_spis = nr_spis;
347 	} else {
348 		u32 typer;
349 
350 		/* Graviton should always have explicit spi_start/nr_spis */
351 		if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY) {
352 			ret = -EINVAL;
353 			goto err_iounmap;
354 		}
355 		typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);
356 
357 		v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
358 		v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
359 	}
360 
361 	if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
362 		ret = -EINVAL;
363 		goto err_iounmap;
364 	}
365 
366 	/*
367 	 * APM X-Gene GICv2m implementation has an erratum where
368 	 * the MSI data needs to be the offset from the spi_start
369 	 * in order to trigger the correct MSI interrupt. This is
370 	 * different from the standard GICv2m implementation where
371 	 * the MSI data is the absolute value within the range from
372 	 * spi_start to (spi_start + num_spis).
373 	 *
374 	 * Broadom NS2 GICv2m implementation has an erratum where the MSI data
375 	 * is 'spi_number - 32'
376 	 *
377 	 * Reading that register fails on the Graviton implementation
378 	 */
379 	if (!(v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)) {
380 		switch (readl_relaxed(v2m->base + V2M_MSI_IIDR)) {
381 		case XGENE_GICV2M_MSI_IIDR:
382 			v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
383 			v2m->spi_offset = v2m->spi_start;
384 			break;
385 		case BCM_NS2_GICV2M_MSI_IIDR:
386 			v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
387 			v2m->spi_offset = 32;
388 			break;
389 		}
390 	}
391 	v2m->bm = kcalloc(BITS_TO_LONGS(v2m->nr_spis), sizeof(long),
392 			  GFP_KERNEL);
393 	if (!v2m->bm) {
394 		ret = -ENOMEM;
395 		goto err_iounmap;
396 	}
397 
398 	list_add_tail(&v2m->entry, &v2m_nodes);
399 
400 	pr_info("range%pR, SPI[%d:%d]\n", res,
401 		v2m->spi_start, (v2m->spi_start + v2m->nr_spis - 1));
402 	return 0;
403 
404 err_iounmap:
405 	iounmap(v2m->base);
406 err_free_v2m:
407 	kfree(v2m);
408 	return ret;
409 }
410 
411 static struct of_device_id gicv2m_device_id[] = {
412 	{	.compatible	= "arm,gic-v2m-frame",	},
413 	{},
414 };
415 
416 static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
417 				 struct irq_domain *parent)
418 {
419 	int ret = 0;
420 	struct device_node *node = to_of_node(parent_handle);
421 	struct device_node *child;
422 
423 	for (child = of_find_matching_node(node, gicv2m_device_id); child;
424 	     child = of_find_matching_node(child, gicv2m_device_id)) {
425 		u32 spi_start = 0, nr_spis = 0;
426 		struct resource res;
427 
428 		if (!of_find_property(child, "msi-controller", NULL))
429 			continue;
430 
431 		ret = of_address_to_resource(child, 0, &res);
432 		if (ret) {
433 			pr_err("Failed to allocate v2m resource.\n");
434 			break;
435 		}
436 
437 		if (!of_property_read_u32(child, "arm,msi-base-spi",
438 					  &spi_start) &&
439 		    !of_property_read_u32(child, "arm,msi-num-spis", &nr_spis))
440 			pr_info("DT overriding V2M MSI_TYPER (base:%u, num:%u)\n",
441 				spi_start, nr_spis);
442 
443 		ret = gicv2m_init_one(&child->fwnode, spi_start, nr_spis,
444 				      &res, 0);
445 		if (ret) {
446 			of_node_put(child);
447 			break;
448 		}
449 	}
450 
451 	if (!ret)
452 		ret = gicv2m_allocate_domains(parent);
453 	if (ret)
454 		gicv2m_teardown();
455 	return ret;
456 }
457 
458 #ifdef CONFIG_ACPI
459 static int acpi_num_msi;
460 
461 static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
462 {
463 	struct v2m_data *data;
464 
465 	if (WARN_ON(acpi_num_msi <= 0))
466 		return NULL;
467 
468 	/* We only return the fwnode of the first MSI frame. */
469 	data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
470 	if (!data)
471 		return NULL;
472 
473 	return data->fwnode;
474 }
475 
476 static bool acpi_check_amazon_graviton_quirks(void)
477 {
478 	static struct acpi_table_madt *madt;
479 	acpi_status status;
480 	bool rc = false;
481 
482 #define ACPI_AMZN_OEM_ID		"AMAZON"
483 
484 	status = acpi_get_table(ACPI_SIG_MADT, 0,
485 				(struct acpi_table_header **)&madt);
486 
487 	if (ACPI_FAILURE(status) || !madt)
488 		return rc;
489 	rc = !memcmp(madt->header.oem_id, ACPI_AMZN_OEM_ID, ACPI_OEM_ID_SIZE);
490 	acpi_put_table((struct acpi_table_header *)madt);
491 
492 	return rc;
493 }
494 
495 static int __init
496 acpi_parse_madt_msi(union acpi_subtable_headers *header,
497 		    const unsigned long end)
498 {
499 	int ret;
500 	struct resource res;
501 	u32 spi_start = 0, nr_spis = 0;
502 	struct acpi_madt_generic_msi_frame *m;
503 	struct fwnode_handle *fwnode;
504 	u32 flags = 0;
505 
506 	m = (struct acpi_madt_generic_msi_frame *)header;
507 	if (BAD_MADT_ENTRY(m, end))
508 		return -EINVAL;
509 
510 	res.start = m->base_address;
511 	res.end = m->base_address + SZ_4K - 1;
512 	res.flags = IORESOURCE_MEM;
513 
514 	if (acpi_check_amazon_graviton_quirks()) {
515 		pr_info("applying Amazon Graviton quirk\n");
516 		res.end = res.start + SZ_8K - 1;
517 		flags |= GICV2M_GRAVITON_ADDRESS_ONLY;
518 		gicv2m_msi_domain_info.flags &= ~MSI_FLAG_MULTI_PCI_MSI;
519 	}
520 
521 	if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
522 		spi_start = m->spi_base;
523 		nr_spis = m->spi_count;
524 
525 		pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
526 			spi_start, nr_spis);
527 	}
528 
529 	fwnode = irq_domain_alloc_fwnode(&res.start);
530 	if (!fwnode) {
531 		pr_err("Unable to allocate GICv2m domain token\n");
532 		return -EINVAL;
533 	}
534 
535 	ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res, flags);
536 	if (ret)
537 		irq_domain_free_fwnode(fwnode);
538 
539 	return ret;
540 }
541 
542 static int __init gicv2m_acpi_init(struct irq_domain *parent)
543 {
544 	int ret;
545 
546 	if (acpi_num_msi > 0)
547 		return 0;
548 
549 	acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
550 				      acpi_parse_madt_msi, 0);
551 
552 	if (acpi_num_msi <= 0)
553 		goto err_out;
554 
555 	ret = gicv2m_allocate_domains(parent);
556 	if (ret)
557 		goto err_out;
558 
559 	pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);
560 
561 	return 0;
562 
563 err_out:
564 	gicv2m_teardown();
565 	return -EINVAL;
566 }
567 #else /* CONFIG_ACPI */
568 static int __init gicv2m_acpi_init(struct irq_domain *parent)
569 {
570 	return -EINVAL;
571 }
572 #endif /* CONFIG_ACPI */
573 
574 int __init gicv2m_init(struct fwnode_handle *parent_handle,
575 		       struct irq_domain *parent)
576 {
577 	if (is_of_node(parent_handle))
578 		return gicv2m_of_init(parent_handle, parent);
579 
580 	return gicv2m_acpi_init(parent);
581 }
582