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/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#include <linux/irqchip/arm-gic-common.h>
28
29/*
30* MSI_TYPER:
31* [31:26] Reserved
32* [25:16] lowest SPI assigned to MSI
33* [15:10] Reserved
34* [9:0] Numer of SPIs assigned to MSI
35*/
36#define V2M_MSI_TYPER 0x008
37#define V2M_MSI_TYPER_BASE_SHIFT 16
38#define V2M_MSI_TYPER_BASE_MASK 0x3FF
39#define V2M_MSI_TYPER_NUM_MASK 0x3FF
40#define V2M_MSI_SETSPI_NS 0x040
41#define V2M_MIN_SPI 32
42#define V2M_MAX_SPI 1019
43#define V2M_MSI_IIDR 0xFCC
44
45#define V2M_MSI_TYPER_BASE_SPI(x) \
46 (((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)
47
48#define V2M_MSI_TYPER_NUM_SPI(x) ((x) & V2M_MSI_TYPER_NUM_MASK)
49
50/* APM X-Gene with GICv2m MSI_IIDR register value */
51#define XGENE_GICV2M_MSI_IIDR 0x06000170
52
53/* Broadcom NS2 GICv2m MSI_IIDR register value */
54#define BCM_NS2_GICV2M_MSI_IIDR 0x0000013f
55
56/* List of flags for specific v2m implementation */
57#define GICV2M_NEEDS_SPI_OFFSET 0x00000001
58#define GICV2M_GRAVITON_ADDRESS_ONLY 0x00000002
59
60static LIST_HEAD(v2m_nodes);
61static DEFINE_SPINLOCK(v2m_lock);
62
63struct v2m_data {
64 struct list_head entry;
65 struct fwnode_handle *fwnode;
66 struct resource res; /* GICv2m resource */
67 void __iomem *base; /* GICv2m virt address */
68 u32 spi_start; /* The SPI number that MSIs start */
69 u32 nr_spis; /* The number of SPIs for MSIs */
70 u32 spi_offset; /* offset to be subtracted from SPI number */
71 unsigned long *bm; /* MSI vector bitmap */
72 u32 flags; /* v2m flags for specific implementation */
73};
74
75static void gicv2m_mask_msi_irq(struct irq_data *d)
76{
77 pci_msi_mask_irq(data: d);
78 irq_chip_mask_parent(data: d);
79}
80
81static void gicv2m_unmask_msi_irq(struct irq_data *d)
82{
83 pci_msi_unmask_irq(data: d);
84 irq_chip_unmask_parent(data: d);
85}
86
87static struct irq_chip gicv2m_msi_irq_chip = {
88 .name = "MSI",
89 .irq_mask = gicv2m_mask_msi_irq,
90 .irq_unmask = gicv2m_unmask_msi_irq,
91 .irq_eoi = irq_chip_eoi_parent,
92};
93
94static 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
100static 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
108static 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(d: data);
111 phys_addr_t addr = gicv2m_get_msi_addr(v2m, hwirq: 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(desc: irq_data_get_msi_desc(d: data), msg);
124}
125
126static 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
135static 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(fwnode: 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(fwnode: 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, irq_base: virq, nr_irqs: 1, arg: &fwspec);
159 if (err)
160 return err;
161
162 /* Configure the interrupt line to be edge */
163 d = irq_domain_get_irq_data(domain: domain->parent, virq);
164 d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
165 return 0;
166}
167
168static void gicv2m_unalloc_msi(struct v2m_data *v2m, unsigned int hwirq,
169 int nr_irqs)
170{
171 spin_lock(lock: &v2m_lock);
172 bitmap_release_region(bitmap: v2m->bm, pos: hwirq - v2m->spi_start,
173 order: get_count_order(count: nr_irqs));
174 spin_unlock(lock: &v2m_lock);
175}
176
177static 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(lock: &v2m_lock);
185 list_for_each_entry(tmp, &v2m_nodes, entry) {
186 offset = bitmap_find_free_region(bitmap: tmp->bm, bits: tmp->nr_spis,
187 order: get_count_order(count: nr_irqs));
188 if (offset >= 0) {
189 v2m = tmp;
190 break;
191 }
192 }
193 spin_unlock(lock: &v2m_lock);
194
195 if (!v2m)
196 return -ENOSPC;
197
198 hwirq = v2m->spi_start + offset;
199
200 err = iommu_dma_prepare_msi(desc: info->desc,
201 msi_addr: 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: virq + i, hwirq: hwirq + i);
207 if (err)
208 goto fail;
209
210 irq_domain_set_hwirq_and_chip(domain, virq: virq + i, hwirq: hwirq + i,
211 chip: &gicv2m_irq_chip, chip_data: v2m);
212 }
213
214 return 0;
215
216fail:
217 irq_domain_free_irqs_parent(domain, irq_base: virq, nr_irqs);
218 gicv2m_unalloc_msi(v2m, hwirq, nr_irqs);
219 return err;
220}
221
222static 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, hwirq: d->hwirq, nr_irqs);
229 irq_domain_free_irqs_parent(domain, irq_base: virq, nr_irqs);
230}
231
232static const struct irq_domain_ops gicv2m_domain_ops = {
233 .alloc = gicv2m_irq_domain_alloc,
234 .free = gicv2m_irq_domain_free,
235};
236
237static 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
253static struct irq_chip gicv2m_pmsi_irq_chip = {
254 .name = "pMSI",
255};
256
257static struct msi_domain_ops gicv2m_pmsi_ops = {
258};
259
260static 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
266static void __init 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(entry: &v2m->entry);
272 bitmap_free(bitmap: v2m->bm);
273 iounmap(addr: v2m->base);
274 of_node_put(to_of_node(v2m->fwnode));
275 if (is_fwnode_irqchip(fwnode: v2m->fwnode))
276 irq_domain_free_fwnode(fwnode: v2m->fwnode);
277 kfree(objp: v2m);
278 }
279}
280
281static __init 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_hierarchy(parent, flags: 0, size: 0, fwnode: v2m->fwnode,
291 ops: &gicv2m_domain_ops, host_data: 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(domain: inner_domain, bus_token: DOMAIN_BUS_NEXUS);
298 pci_domain = pci_msi_create_irq_domain(fwnode: v2m->fwnode,
299 info: &gicv2m_msi_domain_info,
300 parent: inner_domain);
301 plat_domain = platform_msi_create_irq_domain(fwnode: v2m->fwnode,
302 info: &gicv2m_pmsi_domain_info,
303 parent: 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(host: plat_domain);
308 if (pci_domain)
309 irq_domain_remove(host: pci_domain);
310 irq_domain_remove(host: inner_domain);
311 return -ENOMEM;
312 }
313
314 return 0;
315}
316
317static 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(size: sizeof(struct v2m_data), GFP_KERNEL);
325 if (!v2m)
326 return -ENOMEM;
327
328 INIT_LIST_HEAD(list: &v2m->entry);
329 v2m->fwnode = fwnode;
330 v2m->flags = flags;
331
332 memcpy(&v2m->res, res, sizeof(struct resource));
333
334 v2m->base = ioremap(offset: v2m->res.start, size: resource_size(res: &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(base: v2m->spi_start, num: 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(nbits: v2m->nr_spis, GFP_KERNEL);
389 if (!v2m->bm) {
390 ret = -ENOMEM;
391 goto err_iounmap;
392 }
393
394 list_add_tail(new: &v2m->entry, head: &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
400err_iounmap:
401 iounmap(addr: v2m->base);
402err_free_v2m:
403 kfree(objp: v2m);
404 return ret;
405}
406
407static __initconst struct of_device_id gicv2m_device_id[] = {
408 { .compatible = "arm,gic-v2m-frame", },
409 {},
410};
411
412static 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(from: node, matches: gicv2m_device_id); child;
420 child = of_find_matching_node(from: child, matches: gicv2m_device_id)) {
421 u32 spi_start = 0, nr_spis = 0;
422 struct resource res;
423
424 if (!of_property_read_bool(np: child, propname: "msi-controller"))
425 continue;
426
427 ret = of_address_to_resource(dev: child, index: 0, r: &res);
428 if (ret) {
429 pr_err("Failed to allocate v2m resource.\n");
430 break;
431 }
432
433 if (!of_property_read_u32(np: child, propname: "arm,msi-base-spi",
434 out_value: &spi_start) &&
435 !of_property_read_u32(np: child, propname: "arm,msi-num-spis", out_value: &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(fwnode: &child->fwnode, spi_start, nr_spis,
440 res: &res, flags: 0);
441 if (ret) {
442 of_node_put(node: 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
455static int acpi_num_msi;
456
457static __init 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
472static __init 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, instance: 0,
481 out_table: (struct acpi_table_header **)&madt);
482
483 if (ACPI_FAILURE(status) || !madt)
484 return rc;
485 rc = !memcmp(p: madt->header.oem_id, ACPI_AMZN_OEM_ID, ACPI_OEM_ID_SIZE);
486 acpi_put_table(table: (struct acpi_table_header *)madt);
487
488 return rc;
489}
490
491static int __init
492acpi_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(pa: &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: &res, flags);
532 if (ret)
533 irq_domain_free_fwnode(fwnode);
534
535 return ret;
536}
537
538static 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(id: ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
546 handler: acpi_parse_madt_msi, max_entries: 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(fn: &gicv2m_get_fwnode);
556
557 return 0;
558
559err_out:
560 gicv2m_teardown();
561 return -EINVAL;
562}
563#else /* CONFIG_ACPI */
564static int __init gicv2m_acpi_init(struct irq_domain *parent)
565{
566 return -EINVAL;
567}
568#endif /* CONFIG_ACPI */
569
570int __init gicv2m_init(struct fwnode_handle *parent_handle,
571 struct irq_domain *parent)
572{
573 if (is_of_node(fwnode: parent_handle))
574 return gicv2m_of_init(parent_handle, parent);
575
576 return gicv2m_acpi_init(parent);
577}
578

source code of linux/drivers/irqchip/irq-gic-v2m.c