linux/drivers/irqchip/irq-gic-v2m.c
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   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
  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(d);
  78        irq_chip_mask_parent(d);
  79}
  80
  81static void gicv2m_unmask_msi_irq(struct irq_data *d)
  82{
  83        pci_msi_unmask_irq(d);
  84        irq_chip_unmask_parent(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        .irq_write_msi_msg      = pci_msi_domain_write_msg,
  93};
  94
  95static 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
 101static 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
 116static 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
 125static 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
 158static 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
 167static 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
 200fail:
 201        irq_domain_free_irqs_parent(domain, virq, nr_irqs);
 202        gicv2m_unalloc_msi(v2m, hwirq, nr_irqs);
 203        return err;
 204}
 205
 206static 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
 216static const struct irq_domain_ops gicv2m_domain_ops = {
 217        .alloc                  = gicv2m_irq_domain_alloc,
 218        .free                   = gicv2m_irq_domain_free,
 219};
 220
 221static 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
 237static struct irq_chip gicv2m_pmsi_irq_chip = {
 238        .name                   = "pMSI",
 239};
 240
 241static struct msi_domain_ops gicv2m_pmsi_ops = {
 242};
 243
 244static 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
 250static 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
 265static 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
 302static 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
 377err_iounmap:
 378        iounmap(v2m->base);
 379err_free_v2m:
 380        kfree(v2m);
 381        return ret;
 382}
 383
 384static struct of_device_id gicv2m_device_id[] = {
 385        {       .compatible     = "arm,gic-v2m-frame",  },
 386        {},
 387};
 388
 389static 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
 431static int acpi_num_msi;
 432
 433static 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
 448static int __init
 449acpi_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
 487static 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
 508err_out:
 509        gicv2m_teardown();
 510        return -EINVAL;
 511}
 512#else /* CONFIG_ACPI */
 513static int __init gicv2m_acpi_init(struct irq_domain *parent)
 514{
 515        return -EINVAL;
 516}
 517#endif /* CONFIG_ACPI */
 518
 519int __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