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