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/msi.h>
21 #include <linux/of_address.h>
22 #include <linux/of_pci.h>
23 #include <linux/slab.h>
24 #include <linux/spinlock.h>
25 #include <linux/irqchip/arm-gic.h>
26
27 /*
28 * MSI_TYPER:
29 * [31:26] Reserved
30 * [25:16] lowest SPI assigned to MSI
31 * [15:10] Reserved
32 * [9:0] Numer of SPIs assigned to MSI
33 */
34 #define V2M_MSI_TYPER 0x008
35 #define V2M_MSI_TYPER_BASE_SHIFT 16
36 #define V2M_MSI_TYPER_BASE_MASK 0x3FF
37 #define V2M_MSI_TYPER_NUM_MASK 0x3FF
38 #define V2M_MSI_SETSPI_NS 0x040
39 #define V2M_MIN_SPI 32
40 #define V2M_MAX_SPI 1019
41 #define V2M_MSI_IIDR 0xFCC
42
43 #define V2M_MSI_TYPER_BASE_SPI(x) \
44 (((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)
45
46 #define V2M_MSI_TYPER_NUM_SPI(x) ((x) & V2M_MSI_TYPER_NUM_MASK)
47
48 /* APM X-Gene with GICv2m MSI_IIDR register value */
49 #define XGENE_GICV2M_MSI_IIDR 0x06000170
50
51 /* Broadcom NS2 GICv2m MSI_IIDR register value */
52 #define BCM_NS2_GICV2M_MSI_IIDR 0x0000013f
53
54 /* List of flags for specific v2m implementation */
55 #define GICV2M_NEEDS_SPI_OFFSET 0x00000001
56 #define GICV2M_GRAVITON_ADDRESS_ONLY 0x00000002
57
58 static LIST_HEAD(v2m_nodes);
59 static DEFINE_SPINLOCK(v2m_lock);
60
61 struct v2m_data {
62 struct list_head entry;
63 struct fwnode_handle *fwnode;
64 struct resource res; /* GICv2m resource */
65 void __iomem *base; /* GICv2m virt address */
66 u32 spi_start; /* The SPI number that MSIs start */
67 u32 nr_spis; /* The number of SPIs for MSIs */
68 u32 spi_offset; /* offset to be subtracted from SPI number */
69 unsigned long *bm; /* MSI vector bitmap */
70 u32 flags; /* v2m flags for specific implementation */
71 };
72
gicv2m_mask_msi_irq(struct irq_data * d)73 static void gicv2m_mask_msi_irq(struct irq_data *d)
74 {
75 pci_msi_mask_irq(d);
76 irq_chip_mask_parent(d);
77 }
78
gicv2m_unmask_msi_irq(struct irq_data * d)79 static void gicv2m_unmask_msi_irq(struct irq_data *d)
80 {
81 pci_msi_unmask_irq(d);
82 irq_chip_unmask_parent(d);
83 }
84
85 static struct irq_chip gicv2m_msi_irq_chip = {
86 .name = "MSI",
87 .irq_mask = gicv2m_mask_msi_irq,
88 .irq_unmask = gicv2m_unmask_msi_irq,
89 .irq_eoi = irq_chip_eoi_parent,
90 .irq_write_msi_msg = pci_msi_domain_write_msg,
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
gicv2m_get_msi_addr(struct v2m_data * v2m,int hwirq)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
gicv2m_compose_msi_msg(struct irq_data * data,struct msi_msg * msg)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
gicv2m_irq_gic_domain_alloc(struct irq_domain * domain,unsigned int virq,irq_hw_number_t hwirq)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
gicv2m_unalloc_msi(struct v2m_data * v2m,unsigned int hwirq,int nr_irqs)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
gicv2m_irq_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * args)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
gicv2m_irq_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)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
is_msi_spi_valid(u32 base,u32 num)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
gicv2m_teardown(void)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 kfree(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
gicv2m_allocate_domains(struct irq_domain * parent)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
gicv2m_init_one(struct fwnode_handle * fwnode,u32 spi_start,u32 nr_spis,struct resource * res,u32 flags)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 pr_err("Failed to allocate struct v2m_data.\n");
327 return -ENOMEM;
328 }
329
330 INIT_LIST_HEAD(&v2m->entry);
331 v2m->fwnode = fwnode;
332 v2m->flags = flags;
333
334 memcpy(&v2m->res, res, sizeof(struct resource));
335
336 v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
337 if (!v2m->base) {
338 pr_err("Failed to map GICv2m resource\n");
339 ret = -ENOMEM;
340 goto err_free_v2m;
341 }
342
343 if (spi_start && nr_spis) {
344 v2m->spi_start = spi_start;
345 v2m->nr_spis = nr_spis;
346 } else {
347 u32 typer;
348
349 /* Graviton should always have explicit spi_start/nr_spis */
350 if (v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY) {
351 ret = -EINVAL;
352 goto err_iounmap;
353 }
354 typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);
355
356 v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
357 v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
358 }
359
360 if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
361 ret = -EINVAL;
362 goto err_iounmap;
363 }
364
365 /*
366 * APM X-Gene GICv2m implementation has an erratum where
367 * the MSI data needs to be the offset from the spi_start
368 * in order to trigger the correct MSI interrupt. This is
369 * different from the standard GICv2m implementation where
370 * the MSI data is the absolute value within the range from
371 * spi_start to (spi_start + num_spis).
372 *
373 * Broadom NS2 GICv2m implementation has an erratum where the MSI data
374 * is 'spi_number - 32'
375 *
376 * Reading that register fails on the Graviton implementation
377 */
378 if (!(v2m->flags & GICV2M_GRAVITON_ADDRESS_ONLY)) {
379 switch (readl_relaxed(v2m->base + V2M_MSI_IIDR)) {
380 case XGENE_GICV2M_MSI_IIDR:
381 v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
382 v2m->spi_offset = v2m->spi_start;
383 break;
384 case BCM_NS2_GICV2M_MSI_IIDR:
385 v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
386 v2m->spi_offset = 32;
387 break;
388 }
389 }
390 v2m->bm = kcalloc(BITS_TO_LONGS(v2m->nr_spis), sizeof(long),
391 GFP_KERNEL);
392 if (!v2m->bm) {
393 ret = -ENOMEM;
394 goto err_iounmap;
395 }
396
397 list_add_tail(&v2m->entry, &v2m_nodes);
398
399 pr_info("range%pR, SPI[%d:%d]\n", res,
400 v2m->spi_start, (v2m->spi_start + v2m->nr_spis - 1));
401 return 0;
402
403 err_iounmap:
404 iounmap(v2m->base);
405 err_free_v2m:
406 kfree(v2m);
407 return ret;
408 }
409
410 static struct of_device_id gicv2m_device_id[] = {
411 { .compatible = "arm,gic-v2m-frame", },
412 {},
413 };
414
gicv2m_of_init(struct fwnode_handle * parent_handle,struct irq_domain * parent)415 static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
416 struct irq_domain *parent)
417 {
418 int ret = 0;
419 struct device_node *node = to_of_node(parent_handle);
420 struct device_node *child;
421
422 for (child = of_find_matching_node(node, gicv2m_device_id); child;
423 child = of_find_matching_node(child, gicv2m_device_id)) {
424 u32 spi_start = 0, nr_spis = 0;
425 struct resource res;
426
427 if (!of_find_property(child, "msi-controller", NULL))
428 continue;
429
430 ret = of_address_to_resource(child, 0, &res);
431 if (ret) {
432 pr_err("Failed to allocate v2m resource.\n");
433 break;
434 }
435
436 if (!of_property_read_u32(child, "arm,msi-base-spi",
437 &spi_start) &&
438 !of_property_read_u32(child, "arm,msi-num-spis", &nr_spis))
439 pr_info("DT overriding V2M MSI_TYPER (base:%u, num:%u)\n",
440 spi_start, nr_spis);
441
442 ret = gicv2m_init_one(&child->fwnode, spi_start, nr_spis,
443 &res, 0);
444 if (ret) {
445 of_node_put(child);
446 break;
447 }
448 }
449
450 if (!ret)
451 ret = gicv2m_allocate_domains(parent);
452 if (ret)
453 gicv2m_teardown();
454 return ret;
455 }
456
457 #ifdef CONFIG_ACPI
458 static int acpi_num_msi;
459
gicv2m_get_fwnode(struct device * dev)460 static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
461 {
462 struct v2m_data *data;
463
464 if (WARN_ON(acpi_num_msi <= 0))
465 return NULL;
466
467 /* We only return the fwnode of the first MSI frame. */
468 data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
469 if (!data)
470 return NULL;
471
472 return data->fwnode;
473 }
474
acpi_check_amazon_graviton_quirks(void)475 static bool acpi_check_amazon_graviton_quirks(void)
476 {
477 static struct acpi_table_madt *madt;
478 acpi_status status;
479 bool rc = false;
480
481 #define ACPI_AMZN_OEM_ID "AMAZON"
482
483 status = acpi_get_table(ACPI_SIG_MADT, 0,
484 (struct acpi_table_header **)&madt);
485
486 if (ACPI_FAILURE(status) || !madt)
487 return rc;
488 rc = !memcmp(madt->header.oem_id, ACPI_AMZN_OEM_ID, ACPI_OEM_ID_SIZE);
489 acpi_put_table((struct acpi_table_header *)madt);
490
491 return rc;
492 }
493
494 static int __init
acpi_parse_madt_msi(union acpi_subtable_headers * header,const unsigned long end)495 acpi_parse_madt_msi(union acpi_subtable_headers *header,
496 const unsigned long end)
497 {
498 int ret;
499 struct resource res;
500 u32 spi_start = 0, nr_spis = 0;
501 struct acpi_madt_generic_msi_frame *m;
502 struct fwnode_handle *fwnode;
503 u32 flags = 0;
504
505 m = (struct acpi_madt_generic_msi_frame *)header;
506 if (BAD_MADT_ENTRY(m, end))
507 return -EINVAL;
508
509 res.start = m->base_address;
510 res.end = m->base_address + SZ_4K - 1;
511 res.flags = IORESOURCE_MEM;
512
513 if (acpi_check_amazon_graviton_quirks()) {
514 pr_info("applying Amazon Graviton quirk\n");
515 res.end = res.start + SZ_8K - 1;
516 flags |= GICV2M_GRAVITON_ADDRESS_ONLY;
517 gicv2m_msi_domain_info.flags &= ~MSI_FLAG_MULTI_PCI_MSI;
518 }
519
520 if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
521 spi_start = m->spi_base;
522 nr_spis = m->spi_count;
523
524 pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
525 spi_start, nr_spis);
526 }
527
528 fwnode = irq_domain_alloc_fwnode(&res.start);
529 if (!fwnode) {
530 pr_err("Unable to allocate GICv2m domain token\n");
531 return -EINVAL;
532 }
533
534 ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res, flags);
535 if (ret)
536 irq_domain_free_fwnode(fwnode);
537
538 return ret;
539 }
540
gicv2m_acpi_init(struct irq_domain * parent)541 static int __init gicv2m_acpi_init(struct irq_domain *parent)
542 {
543 int ret;
544
545 if (acpi_num_msi > 0)
546 return 0;
547
548 acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
549 acpi_parse_madt_msi, 0);
550
551 if (acpi_num_msi <= 0)
552 goto err_out;
553
554 ret = gicv2m_allocate_domains(parent);
555 if (ret)
556 goto err_out;
557
558 pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);
559
560 return 0;
561
562 err_out:
563 gicv2m_teardown();
564 return -EINVAL;
565 }
566 #else /* CONFIG_ACPI */
gicv2m_acpi_init(struct irq_domain * parent)567 static int __init gicv2m_acpi_init(struct irq_domain *parent)
568 {
569 return -EINVAL;
570 }
571 #endif /* CONFIG_ACPI */
572
gicv2m_init(struct fwnode_handle * parent_handle,struct irq_domain * parent)573 int __init gicv2m_init(struct fwnode_handle *parent_handle,
574 struct irq_domain *parent)
575 {
576 if (is_of_node(parent_handle))
577 return gicv2m_of_init(parent_handle, parent);
578
579 return gicv2m_acpi_init(parent);
580 }
581