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),
  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{
 160        int pos;
 161
 162        pos = hwirq - v2m->spi_start;
 163        if (pos < 0 || pos >= v2m->nr_spis) {
 164                pr_err("Failed to teardown msi. Invalid hwirq %d\n", hwirq);
 165                return;
 166        }
 167
 168        spin_lock(&v2m_lock);
 169        __clear_bit(pos, v2m->bm);
 170        spin_unlock(&v2m_lock);
 171}
 172
 173static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 174                                   unsigned int nr_irqs, void *args)
 175{
 176        struct v2m_data *v2m = NULL, *tmp;
 177        int hwirq, offset, err = 0;
 178
 179        spin_lock(&v2m_lock);
 180        list_for_each_entry(tmp, &v2m_nodes, entry) {
 181                offset = find_first_zero_bit(tmp->bm, tmp->nr_spis);
 182                if (offset < tmp->nr_spis) {
 183                        __set_bit(offset, tmp->bm);
 184                        v2m = tmp;
 185                        break;
 186                }
 187        }
 188        spin_unlock(&v2m_lock);
 189
 190        if (!v2m)
 191                return -ENOSPC;
 192
 193        hwirq = v2m->spi_start + offset;
 194
 195        err = gicv2m_irq_gic_domain_alloc(domain, virq, hwirq);
 196        if (err) {
 197                gicv2m_unalloc_msi(v2m, hwirq);
 198                return err;
 199        }
 200
 201        irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 202                                      &gicv2m_irq_chip, v2m);
 203
 204        return 0;
 205}
 206
 207static void gicv2m_irq_domain_free(struct irq_domain *domain,
 208                                   unsigned int virq, unsigned int nr_irqs)
 209{
 210        struct irq_data *d = irq_domain_get_irq_data(domain, virq);
 211        struct v2m_data *v2m = irq_data_get_irq_chip_data(d);
 212
 213        BUG_ON(nr_irqs != 1);
 214        gicv2m_unalloc_msi(v2m, d->hwirq);
 215        irq_domain_free_irqs_parent(domain, virq, nr_irqs);
 216}
 217
 218static const struct irq_domain_ops gicv2m_domain_ops = {
 219        .alloc                  = gicv2m_irq_domain_alloc,
 220        .free                   = gicv2m_irq_domain_free,
 221};
 222
 223static bool is_msi_spi_valid(u32 base, u32 num)
 224{
 225        if (base < V2M_MIN_SPI) {
 226                pr_err("Invalid MSI base SPI (base:%u)\n", base);
 227                return false;
 228        }
 229
 230        if ((num == 0) || (base + num > V2M_MAX_SPI)) {
 231                pr_err("Number of SPIs (%u) exceed maximum (%u)\n",
 232                       num, V2M_MAX_SPI - V2M_MIN_SPI + 1);
 233                return false;
 234        }
 235
 236        return true;
 237}
 238
 239static struct irq_chip gicv2m_pmsi_irq_chip = {
 240        .name                   = "pMSI",
 241};
 242
 243static struct msi_domain_ops gicv2m_pmsi_ops = {
 244};
 245
 246static struct msi_domain_info gicv2m_pmsi_domain_info = {
 247        .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
 248        .ops    = &gicv2m_pmsi_ops,
 249        .chip   = &gicv2m_pmsi_irq_chip,
 250};
 251
 252static void gicv2m_teardown(void)
 253{
 254        struct v2m_data *v2m, *tmp;
 255
 256        list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) {
 257                list_del(&v2m->entry);
 258                kfree(v2m->bm);
 259                iounmap(v2m->base);
 260                of_node_put(to_of_node(v2m->fwnode));
 261                if (is_fwnode_irqchip(v2m->fwnode))
 262                        irq_domain_free_fwnode(v2m->fwnode);
 263                kfree(v2m);
 264        }
 265}
 266
 267static int gicv2m_allocate_domains(struct irq_domain *parent)
 268{
 269        struct irq_domain *inner_domain, *pci_domain, *plat_domain;
 270        struct v2m_data *v2m;
 271
 272        v2m = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
 273        if (!v2m)
 274                return 0;
 275
 276        inner_domain = irq_domain_create_tree(v2m->fwnode,
 277                                              &gicv2m_domain_ops, v2m);
 278        if (!inner_domain) {
 279                pr_err("Failed to create GICv2m domain\n");
 280                return -ENOMEM;
 281        }
 282
 283        irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
 284        inner_domain->parent = parent;
 285        pci_domain = pci_msi_create_irq_domain(v2m->fwnode,
 286                                               &gicv2m_msi_domain_info,
 287                                               inner_domain);
 288        plat_domain = platform_msi_create_irq_domain(v2m->fwnode,
 289                                                     &gicv2m_pmsi_domain_info,
 290                                                     inner_domain);
 291        if (!pci_domain || !plat_domain) {
 292                pr_err("Failed to create MSI domains\n");
 293                if (plat_domain)
 294                        irq_domain_remove(plat_domain);
 295                if (pci_domain)
 296                        irq_domain_remove(pci_domain);
 297                irq_domain_remove(inner_domain);
 298                return -ENOMEM;
 299        }
 300
 301        return 0;
 302}
 303
 304static int __init gicv2m_init_one(struct fwnode_handle *fwnode,
 305                                  u32 spi_start, u32 nr_spis,
 306                                  struct resource *res)
 307{
 308        int ret;
 309        struct v2m_data *v2m;
 310
 311        v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
 312        if (!v2m) {
 313                pr_err("Failed to allocate struct v2m_data.\n");
 314                return -ENOMEM;
 315        }
 316
 317        INIT_LIST_HEAD(&v2m->entry);
 318        v2m->fwnode = fwnode;
 319
 320        memcpy(&v2m->res, res, sizeof(struct resource));
 321
 322        v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
 323        if (!v2m->base) {
 324                pr_err("Failed to map GICv2m resource\n");
 325                ret = -ENOMEM;
 326                goto err_free_v2m;
 327        }
 328
 329        if (spi_start && nr_spis) {
 330                v2m->spi_start = spi_start;
 331                v2m->nr_spis = nr_spis;
 332        } else {
 333                u32 typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);
 334
 335                v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
 336                v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
 337        }
 338
 339        if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
 340                ret = -EINVAL;
 341                goto err_iounmap;
 342        }
 343
 344        /*
 345         * APM X-Gene GICv2m implementation has an erratum where
 346         * the MSI data needs to be the offset from the spi_start
 347         * in order to trigger the correct MSI interrupt. This is
 348         * different from the standard GICv2m implementation where
 349         * the MSI data is the absolute value within the range from
 350         * spi_start to (spi_start + num_spis).
 351         *
 352         * Broadom NS2 GICv2m implementation has an erratum where the MSI data
 353         * is 'spi_number - 32'
 354         */
 355        switch (readl_relaxed(v2m->base + V2M_MSI_IIDR)) {
 356        case XGENE_GICV2M_MSI_IIDR:
 357                v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
 358                v2m->spi_offset = v2m->spi_start;
 359                break;
 360        case BCM_NS2_GICV2M_MSI_IIDR:
 361                v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
 362                v2m->spi_offset = 32;
 363                break;
 364        }
 365
 366        v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
 367                          GFP_KERNEL);
 368        if (!v2m->bm) {
 369                ret = -ENOMEM;
 370                goto err_iounmap;
 371        }
 372
 373        list_add_tail(&v2m->entry, &v2m_nodes);
 374
 375        pr_info("range%pR, SPI[%d:%d]\n", res,
 376                v2m->spi_start, (v2m->spi_start + v2m->nr_spis - 1));
 377        return 0;
 378
 379err_iounmap:
 380        iounmap(v2m->base);
 381err_free_v2m:
 382        kfree(v2m);
 383        return ret;
 384}
 385
 386static struct of_device_id gicv2m_device_id[] = {
 387        {       .compatible     = "arm,gic-v2m-frame",  },
 388        {},
 389};
 390
 391static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
 392                                 struct irq_domain *parent)
 393{
 394        int ret = 0;
 395        struct device_node *node = to_of_node(parent_handle);
 396        struct device_node *child;
 397
 398        for (child = of_find_matching_node(node, gicv2m_device_id); child;
 399             child = of_find_matching_node(child, gicv2m_device_id)) {
 400                u32 spi_start = 0, nr_spis = 0;
 401                struct resource res;
 402
 403                if (!of_find_property(child, "msi-controller", NULL))
 404                        continue;
 405
 406                ret = of_address_to_resource(child, 0, &res);
 407                if (ret) {
 408                        pr_err("Failed to allocate v2m resource.\n");
 409                        break;
 410                }
 411
 412                if (!of_property_read_u32(child, "arm,msi-base-spi",
 413                                          &spi_start) &&
 414                    !of_property_read_u32(child, "arm,msi-num-spis", &nr_spis))
 415                        pr_info("DT overriding V2M MSI_TYPER (base:%u, num:%u)\n",
 416                                spi_start, nr_spis);
 417
 418                ret = gicv2m_init_one(&child->fwnode, spi_start, nr_spis, &res);
 419                if (ret) {
 420                        of_node_put(child);
 421                        break;
 422                }
 423        }
 424
 425        if (!ret)
 426                ret = gicv2m_allocate_domains(parent);
 427        if (ret)
 428                gicv2m_teardown();
 429        return ret;
 430}
 431
 432#ifdef CONFIG_ACPI
 433static int acpi_num_msi;
 434
 435static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
 436{
 437        struct v2m_data *data;
 438
 439        if (WARN_ON(acpi_num_msi <= 0))
 440                return NULL;
 441
 442        /* We only return the fwnode of the first MSI frame. */
 443        data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
 444        if (!data)
 445                return NULL;
 446
 447        return data->fwnode;
 448}
 449
 450static int __init
 451acpi_parse_madt_msi(struct acpi_subtable_header *header,
 452                    const unsigned long end)
 453{
 454        int ret;
 455        struct resource res;
 456        u32 spi_start = 0, nr_spis = 0;
 457        struct acpi_madt_generic_msi_frame *m;
 458        struct fwnode_handle *fwnode;
 459
 460        m = (struct acpi_madt_generic_msi_frame *)header;
 461        if (BAD_MADT_ENTRY(m, end))
 462                return -EINVAL;
 463
 464        res.start = m->base_address;
 465        res.end = m->base_address + SZ_4K - 1;
 466        res.flags = IORESOURCE_MEM;
 467
 468        if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
 469                spi_start = m->spi_base;
 470                nr_spis = m->spi_count;
 471
 472                pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
 473                        spi_start, nr_spis);
 474        }
 475
 476        fwnode = irq_domain_alloc_fwnode((void *)m->base_address);
 477        if (!fwnode) {
 478                pr_err("Unable to allocate GICv2m domain token\n");
 479                return -EINVAL;
 480        }
 481
 482        ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res);
 483        if (ret)
 484                irq_domain_free_fwnode(fwnode);
 485
 486        return ret;
 487}
 488
 489static int __init gicv2m_acpi_init(struct irq_domain *parent)
 490{
 491        int ret;
 492
 493        if (acpi_num_msi > 0)
 494                return 0;
 495
 496        acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
 497                                      acpi_parse_madt_msi, 0);
 498
 499        if (acpi_num_msi <= 0)
 500                goto err_out;
 501
 502        ret = gicv2m_allocate_domains(parent);
 503        if (ret)
 504                goto err_out;
 505
 506        pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);
 507
 508        return 0;
 509
 510err_out:
 511        gicv2m_teardown();
 512        return -EINVAL;
 513}
 514#else /* CONFIG_ACPI */
 515static int __init gicv2m_acpi_init(struct irq_domain *parent)
 516{
 517        return -EINVAL;
 518}
 519#endif /* CONFIG_ACPI */
 520
 521int __init gicv2m_init(struct fwnode_handle *parent_handle,
 522                       struct irq_domain *parent)
 523{
 524        if (is_of_node(parent_handle))
 525                return gicv2m_of_init(parent_handle, parent);
 526
 527        return gicv2m_acpi_init(parent);
 528}
 529