linux/drivers/irqchip/irq-gic-v2m.c
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   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
  59static LIST_HEAD(v2m_nodes);
  60static DEFINE_SPINLOCK(v2m_lock);
  61
  62struct 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
  74static void gicv2m_mask_msi_irq(struct irq_data *d)
  75{
  76        pci_msi_mask_irq(d);
  77        irq_chip_mask_parent(d);
  78}
  79
  80static void gicv2m_unmask_msi_irq(struct irq_data *d)
  81{
  82        pci_msi_unmask_irq(d);
  83        irq_chip_unmask_parent(d);
  84}
  85
  86static 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
  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(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
 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(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
 168static 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
 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(&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
 216fail:
 217        irq_domain_free_irqs_parent(domain, 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, d->hwirq, nr_irqs);
 229        irq_domain_free_irqs_parent(domain, 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 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
 281static 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
 318static 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         * Broadcom 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
 404err_iounmap:
 405        iounmap(v2m->base);
 406err_free_v2m:
 407        kfree(v2m);
 408        return ret;
 409}
 410
 411static struct of_device_id gicv2m_device_id[] = {
 412        {       .compatible     = "arm,gic-v2m-frame",  },
 413        {},
 414};
 415
 416static 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
 459static int acpi_num_msi;
 460
 461static 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
 476static 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
 495static int __init
 496acpi_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
 542static 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
 563err_out:
 564        gicv2m_teardown();
 565        return -EINVAL;
 566}
 567#else /* CONFIG_ACPI */
 568static int __init gicv2m_acpi_init(struct irq_domain *parent)
 569{
 570        return -EINVAL;
 571}
 572#endif /* CONFIG_ACPI */
 573
 574int __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