linux/arch/powerpc/sysdev/fsl_msi.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2007-2011 Freescale Semiconductor, Inc.
   4 *
   5 * Author: Tony Li <tony.li@freescale.com>
   6 *         Jason Jin <Jason.jin@freescale.com>
   7 *
   8 * The hwirq alloc and free code reuse from sysdev/mpic_msi.c
   9 */
  10#include <linux/irq.h>
  11#include <linux/msi.h>
  12#include <linux/pci.h>
  13#include <linux/slab.h>
  14#include <linux/of_platform.h>
  15#include <linux/interrupt.h>
  16#include <linux/seq_file.h>
  17#include <sysdev/fsl_soc.h>
  18#include <asm/prom.h>
  19#include <asm/hw_irq.h>
  20#include <asm/ppc-pci.h>
  21#include <asm/mpic.h>
  22#include <asm/fsl_hcalls.h>
  23
  24#include "fsl_msi.h"
  25#include "fsl_pci.h"
  26
  27#define MSIIR_OFFSET_MASK       0xfffff
  28#define MSIIR_IBS_SHIFT         0
  29#define MSIIR_SRS_SHIFT         5
  30#define MSIIR1_IBS_SHIFT        4
  31#define MSIIR1_SRS_SHIFT        0
  32#define MSI_SRS_MASK            0xf
  33#define MSI_IBS_MASK            0x1f
  34
  35#define msi_hwirq(msi, msir_index, intr_index) \
  36                ((msir_index) << (msi)->srs_shift | \
  37                 ((intr_index) << (msi)->ibs_shift))
  38
  39static LIST_HEAD(msi_head);
  40
  41struct fsl_msi_feature {
  42        u32 fsl_pic_ip;
  43        u32 msiir_offset; /* Offset of MSIIR, relative to start of MSIR bank */
  44};
  45
  46struct fsl_msi_cascade_data {
  47        struct fsl_msi *msi_data;
  48        int index;
  49        int virq;
  50};
  51
  52static inline u32 fsl_msi_read(u32 __iomem *base, unsigned int reg)
  53{
  54        return in_be32(base + (reg >> 2));
  55}
  56
  57/*
  58 * We do not need this actually. The MSIR register has been read once
  59 * in the cascade interrupt. So, this MSI interrupt has been acked
  60*/
  61static void fsl_msi_end_irq(struct irq_data *d)
  62{
  63}
  64
  65static void fsl_msi_print_chip(struct irq_data *irqd, struct seq_file *p)
  66{
  67        struct fsl_msi *msi_data = irqd->domain->host_data;
  68        irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
  69        int cascade_virq, srs;
  70
  71        srs = (hwirq >> msi_data->srs_shift) & MSI_SRS_MASK;
  72        cascade_virq = msi_data->cascade_array[srs]->virq;
  73
  74        seq_printf(p, " fsl-msi-%d", cascade_virq);
  75}
  76
  77
  78static struct irq_chip fsl_msi_chip = {
  79        .irq_mask       = pci_msi_mask_irq,
  80        .irq_unmask     = pci_msi_unmask_irq,
  81        .irq_ack        = fsl_msi_end_irq,
  82        .irq_print_chip = fsl_msi_print_chip,
  83};
  84
  85static int fsl_msi_host_map(struct irq_domain *h, unsigned int virq,
  86                                irq_hw_number_t hw)
  87{
  88        struct fsl_msi *msi_data = h->host_data;
  89        struct irq_chip *chip = &fsl_msi_chip;
  90
  91        irq_set_status_flags(virq, IRQ_TYPE_EDGE_FALLING);
  92
  93        irq_set_chip_data(virq, msi_data);
  94        irq_set_chip_and_handler(virq, chip, handle_edge_irq);
  95
  96        return 0;
  97}
  98
  99static const struct irq_domain_ops fsl_msi_host_ops = {
 100        .map = fsl_msi_host_map,
 101};
 102
 103static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
 104{
 105        int rc, hwirq;
 106
 107        rc = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS_MAX,
 108                              irq_domain_get_of_node(msi_data->irqhost));
 109        if (rc)
 110                return rc;
 111
 112        /*
 113         * Reserve all the hwirqs
 114         * The available hwirqs will be released in fsl_msi_setup_hwirq()
 115         */
 116        for (hwirq = 0; hwirq < NR_MSI_IRQS_MAX; hwirq++)
 117                msi_bitmap_reserve_hwirq(&msi_data->bitmap, hwirq);
 118
 119        return 0;
 120}
 121
 122static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
 123{
 124        struct msi_desc *entry;
 125        struct fsl_msi *msi_data;
 126        irq_hw_number_t hwirq;
 127
 128        for_each_pci_msi_entry(entry, pdev) {
 129                if (!entry->irq)
 130                        continue;
 131                hwirq = virq_to_hw(entry->irq);
 132                msi_data = irq_get_chip_data(entry->irq);
 133                irq_set_msi_desc(entry->irq, NULL);
 134                irq_dispose_mapping(entry->irq);
 135                msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 136        }
 137
 138        return;
 139}
 140
 141static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
 142                                struct msi_msg *msg,
 143                                struct fsl_msi *fsl_msi_data)
 144{
 145        struct fsl_msi *msi_data = fsl_msi_data;
 146        struct pci_controller *hose = pci_bus_to_host(pdev->bus);
 147        u64 address; /* Physical address of the MSIIR */
 148        int len;
 149        const __be64 *reg;
 150
 151        /* If the msi-address-64 property exists, then use it */
 152        reg = of_get_property(hose->dn, "msi-address-64", &len);
 153        if (reg && (len == sizeof(u64)))
 154                address = be64_to_cpup(reg);
 155        else
 156                address = fsl_pci_immrbar_base(hose) + msi_data->msiir_offset;
 157
 158        msg->address_lo = lower_32_bits(address);
 159        msg->address_hi = upper_32_bits(address);
 160
 161        /*
 162         * MPIC version 2.0 has erratum PIC1. It causes
 163         * that neither MSI nor MSI-X can work fine.
 164         * This is a workaround to allow MSI-X to function
 165         * properly. It only works for MSI-X, we prevent
 166         * MSI on buggy chips in fsl_setup_msi_irqs().
 167         */
 168        if (msi_data->feature & MSI_HW_ERRATA_ENDIAN)
 169                msg->data = __swab32(hwirq);
 170        else
 171                msg->data = hwirq;
 172
 173        pr_debug("%s: allocated srs: %d, ibs: %d\n", __func__,
 174                 (hwirq >> msi_data->srs_shift) & MSI_SRS_MASK,
 175                 (hwirq >> msi_data->ibs_shift) & MSI_IBS_MASK);
 176}
 177
 178static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 179{
 180        struct pci_controller *hose = pci_bus_to_host(pdev->bus);
 181        struct device_node *np;
 182        phandle phandle = 0;
 183        int rc, hwirq = -ENOMEM;
 184        unsigned int virq;
 185        struct msi_desc *entry;
 186        struct msi_msg msg;
 187        struct fsl_msi *msi_data;
 188
 189        if (type == PCI_CAP_ID_MSI) {
 190                /*
 191                 * MPIC version 2.0 has erratum PIC1. For now MSI
 192                 * could not work. So check to prevent MSI from
 193                 * being used on the board with this erratum.
 194                 */
 195                list_for_each_entry(msi_data, &msi_head, list)
 196                        if (msi_data->feature & MSI_HW_ERRATA_ENDIAN)
 197                                return -EINVAL;
 198        }
 199
 200        /*
 201         * If the PCI node has an fsl,msi property, then we need to use it
 202         * to find the specific MSI.
 203         */
 204        np = of_parse_phandle(hose->dn, "fsl,msi", 0);
 205        if (np) {
 206                if (of_device_is_compatible(np, "fsl,mpic-msi") ||
 207                    of_device_is_compatible(np, "fsl,vmpic-msi") ||
 208                    of_device_is_compatible(np, "fsl,vmpic-msi-v4.3"))
 209                        phandle = np->phandle;
 210                else {
 211                        dev_err(&pdev->dev,
 212                                "node %pOF has an invalid fsl,msi phandle %u\n",
 213                                hose->dn, np->phandle);
 214                        return -EINVAL;
 215                }
 216        }
 217
 218        for_each_pci_msi_entry(entry, pdev) {
 219                /*
 220                 * Loop over all the MSI devices until we find one that has an
 221                 * available interrupt.
 222                 */
 223                list_for_each_entry(msi_data, &msi_head, list) {
 224                        /*
 225                         * If the PCI node has an fsl,msi property, then we
 226                         * restrict our search to the corresponding MSI node.
 227                         * The simplest way is to skip over MSI nodes with the
 228                         * wrong phandle. Under the Freescale hypervisor, this
 229                         * has the additional benefit of skipping over MSI
 230                         * nodes that are not mapped in the PAMU.
 231                         */
 232                        if (phandle && (phandle != msi_data->phandle))
 233                                continue;
 234
 235                        hwirq = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
 236                        if (hwirq >= 0)
 237                                break;
 238                }
 239
 240                if (hwirq < 0) {
 241                        rc = hwirq;
 242                        dev_err(&pdev->dev, "could not allocate MSI interrupt\n");
 243                        goto out_free;
 244                }
 245
 246                virq = irq_create_mapping(msi_data->irqhost, hwirq);
 247
 248                if (!virq) {
 249                        dev_err(&pdev->dev, "fail mapping hwirq %i\n", hwirq);
 250                        msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 251                        rc = -ENOSPC;
 252                        goto out_free;
 253                }
 254                /* chip_data is msi_data via host->hostdata in host->map() */
 255                irq_set_msi_desc(virq, entry);
 256
 257                fsl_compose_msi_msg(pdev, hwirq, &msg, msi_data);
 258                pci_write_msi_msg(virq, &msg);
 259        }
 260        return 0;
 261
 262out_free:
 263        /* free by the caller of this function */
 264        return rc;
 265}
 266
 267static irqreturn_t fsl_msi_cascade(int irq, void *data)
 268{
 269        unsigned int cascade_irq;
 270        struct fsl_msi *msi_data;
 271        int msir_index = -1;
 272        u32 msir_value = 0;
 273        u32 intr_index;
 274        u32 have_shift = 0;
 275        struct fsl_msi_cascade_data *cascade_data = data;
 276        irqreturn_t ret = IRQ_NONE;
 277
 278        msi_data = cascade_data->msi_data;
 279
 280        msir_index = cascade_data->index;
 281
 282        if (msir_index >= NR_MSI_REG_MAX)
 283                cascade_irq = 0;
 284
 285        switch (msi_data->feature & FSL_PIC_IP_MASK) {
 286        case FSL_PIC_IP_MPIC:
 287                msir_value = fsl_msi_read(msi_data->msi_regs,
 288                        msir_index * 0x10);
 289                break;
 290        case FSL_PIC_IP_IPIC:
 291                msir_value = fsl_msi_read(msi_data->msi_regs, msir_index * 0x4);
 292                break;
 293#ifdef CONFIG_EPAPR_PARAVIRT
 294        case FSL_PIC_IP_VMPIC: {
 295                unsigned int ret;
 296                ret = fh_vmpic_get_msir(virq_to_hw(irq), &msir_value);
 297                if (ret) {
 298                        pr_err("fsl-msi: fh_vmpic_get_msir() failed for "
 299                               "irq %u (ret=%u)\n", irq, ret);
 300                        msir_value = 0;
 301                }
 302                break;
 303        }
 304#endif
 305        }
 306
 307        while (msir_value) {
 308                intr_index = ffs(msir_value) - 1;
 309
 310                cascade_irq = irq_linear_revmap(msi_data->irqhost,
 311                                msi_hwirq(msi_data, msir_index,
 312                                          intr_index + have_shift));
 313                if (cascade_irq) {
 314                        generic_handle_irq(cascade_irq);
 315                        ret = IRQ_HANDLED;
 316                }
 317                have_shift += intr_index + 1;
 318                msir_value = msir_value >> (intr_index + 1);
 319        }
 320
 321        return ret;
 322}
 323
 324static int fsl_of_msi_remove(struct platform_device *ofdev)
 325{
 326        struct fsl_msi *msi = platform_get_drvdata(ofdev);
 327        int virq, i;
 328
 329        if (msi->list.prev != NULL)
 330                list_del(&msi->list);
 331        for (i = 0; i < NR_MSI_REG_MAX; i++) {
 332                if (msi->cascade_array[i]) {
 333                        virq = msi->cascade_array[i]->virq;
 334
 335                        BUG_ON(!virq);
 336
 337                        free_irq(virq, msi->cascade_array[i]);
 338                        kfree(msi->cascade_array[i]);
 339                        irq_dispose_mapping(virq);
 340                }
 341        }
 342        if (msi->bitmap.bitmap)
 343                msi_bitmap_free(&msi->bitmap);
 344        if ((msi->feature & FSL_PIC_IP_MASK) != FSL_PIC_IP_VMPIC)
 345                iounmap(msi->msi_regs);
 346        kfree(msi);
 347
 348        return 0;
 349}
 350
 351static struct lock_class_key fsl_msi_irq_class;
 352static struct lock_class_key fsl_msi_irq_request_class;
 353
 354static int fsl_msi_setup_hwirq(struct fsl_msi *msi, struct platform_device *dev,
 355                               int offset, int irq_index)
 356{
 357        struct fsl_msi_cascade_data *cascade_data = NULL;
 358        int virt_msir, i, ret;
 359
 360        virt_msir = irq_of_parse_and_map(dev->dev.of_node, irq_index);
 361        if (!virt_msir) {
 362                dev_err(&dev->dev, "%s: Cannot translate IRQ index %d\n",
 363                        __func__, irq_index);
 364                return 0;
 365        }
 366
 367        cascade_data = kzalloc(sizeof(struct fsl_msi_cascade_data), GFP_KERNEL);
 368        if (!cascade_data) {
 369                dev_err(&dev->dev, "No memory for MSI cascade data\n");
 370                return -ENOMEM;
 371        }
 372        irq_set_lockdep_class(virt_msir, &fsl_msi_irq_class,
 373                              &fsl_msi_irq_request_class);
 374        cascade_data->index = offset;
 375        cascade_data->msi_data = msi;
 376        cascade_data->virq = virt_msir;
 377        msi->cascade_array[irq_index] = cascade_data;
 378
 379        ret = request_irq(virt_msir, fsl_msi_cascade, IRQF_NO_THREAD,
 380                          "fsl-msi-cascade", cascade_data);
 381        if (ret) {
 382                dev_err(&dev->dev, "failed to request_irq(%d), ret = %d\n",
 383                        virt_msir, ret);
 384                return ret;
 385        }
 386
 387        /* Release the hwirqs corresponding to this MSI register */
 388        for (i = 0; i < IRQS_PER_MSI_REG; i++)
 389                msi_bitmap_free_hwirqs(&msi->bitmap,
 390                                       msi_hwirq(msi, offset, i), 1);
 391
 392        return 0;
 393}
 394
 395static const struct of_device_id fsl_of_msi_ids[];
 396static int fsl_of_msi_probe(struct platform_device *dev)
 397{
 398        const struct of_device_id *match;
 399        struct fsl_msi *msi;
 400        struct resource res, msiir;
 401        int err, i, j, irq_index, count;
 402        const u32 *p;
 403        const struct fsl_msi_feature *features;
 404        int len;
 405        u32 offset;
 406        struct pci_controller *phb;
 407
 408        match = of_match_device(fsl_of_msi_ids, &dev->dev);
 409        if (!match)
 410                return -EINVAL;
 411        features = match->data;
 412
 413        printk(KERN_DEBUG "Setting up Freescale MSI support\n");
 414
 415        msi = kzalloc(sizeof(struct fsl_msi), GFP_KERNEL);
 416        if (!msi) {
 417                dev_err(&dev->dev, "No memory for MSI structure\n");
 418                return -ENOMEM;
 419        }
 420        platform_set_drvdata(dev, msi);
 421
 422        msi->irqhost = irq_domain_add_linear(dev->dev.of_node,
 423                                      NR_MSI_IRQS_MAX, &fsl_msi_host_ops, msi);
 424
 425        if (msi->irqhost == NULL) {
 426                dev_err(&dev->dev, "No memory for MSI irqhost\n");
 427                err = -ENOMEM;
 428                goto error_out;
 429        }
 430
 431        /*
 432         * Under the Freescale hypervisor, the msi nodes don't have a 'reg'
 433         * property.  Instead, we use hypercalls to access the MSI.
 434         */
 435        if ((features->fsl_pic_ip & FSL_PIC_IP_MASK) != FSL_PIC_IP_VMPIC) {
 436                err = of_address_to_resource(dev->dev.of_node, 0, &res);
 437                if (err) {
 438                        dev_err(&dev->dev, "invalid resource for node %pOF\n",
 439                                dev->dev.of_node);
 440                        goto error_out;
 441                }
 442
 443                msi->msi_regs = ioremap(res.start, resource_size(&res));
 444                if (!msi->msi_regs) {
 445                        err = -ENOMEM;
 446                        dev_err(&dev->dev, "could not map node %pOF\n",
 447                                dev->dev.of_node);
 448                        goto error_out;
 449                }
 450                msi->msiir_offset =
 451                        features->msiir_offset + (res.start & 0xfffff);
 452
 453                /*
 454                 * First read the MSIIR/MSIIR1 offset from dts
 455                 * On failure use the hardcode MSIIR offset
 456                 */
 457                if (of_address_to_resource(dev->dev.of_node, 1, &msiir))
 458                        msi->msiir_offset = features->msiir_offset +
 459                                            (res.start & MSIIR_OFFSET_MASK);
 460                else
 461                        msi->msiir_offset = msiir.start & MSIIR_OFFSET_MASK;
 462        }
 463
 464        msi->feature = features->fsl_pic_ip;
 465
 466        /* For erratum PIC1 on MPIC version 2.0*/
 467        if ((features->fsl_pic_ip & FSL_PIC_IP_MASK) == FSL_PIC_IP_MPIC
 468                        && (fsl_mpic_primary_get_version() == 0x0200))
 469                msi->feature |= MSI_HW_ERRATA_ENDIAN;
 470
 471        /*
 472         * Remember the phandle, so that we can match with any PCI nodes
 473         * that have an "fsl,msi" property.
 474         */
 475        msi->phandle = dev->dev.of_node->phandle;
 476
 477        err = fsl_msi_init_allocator(msi);
 478        if (err) {
 479                dev_err(&dev->dev, "Error allocating MSI bitmap\n");
 480                goto error_out;
 481        }
 482
 483        p = of_get_property(dev->dev.of_node, "msi-available-ranges", &len);
 484
 485        if (of_device_is_compatible(dev->dev.of_node, "fsl,mpic-msi-v4.3") ||
 486            of_device_is_compatible(dev->dev.of_node, "fsl,vmpic-msi-v4.3")) {
 487                msi->srs_shift = MSIIR1_SRS_SHIFT;
 488                msi->ibs_shift = MSIIR1_IBS_SHIFT;
 489                if (p)
 490                        dev_warn(&dev->dev, "%s: dose not support msi-available-ranges property\n",
 491                                __func__);
 492
 493                for (irq_index = 0; irq_index < NR_MSI_REG_MSIIR1;
 494                     irq_index++) {
 495                        err = fsl_msi_setup_hwirq(msi, dev,
 496                                                  irq_index, irq_index);
 497                        if (err)
 498                                goto error_out;
 499                }
 500        } else {
 501                static const u32 all_avail[] =
 502                        { 0, NR_MSI_REG_MSIIR * IRQS_PER_MSI_REG };
 503
 504                msi->srs_shift = MSIIR_SRS_SHIFT;
 505                msi->ibs_shift = MSIIR_IBS_SHIFT;
 506
 507                if (p && len % (2 * sizeof(u32)) != 0) {
 508                        dev_err(&dev->dev, "%s: Malformed msi-available-ranges property\n",
 509                                __func__);
 510                        err = -EINVAL;
 511                        goto error_out;
 512                }
 513
 514                if (!p) {
 515                        p = all_avail;
 516                        len = sizeof(all_avail);
 517                }
 518
 519                for (irq_index = 0, i = 0; i < len / (2 * sizeof(u32)); i++) {
 520                        if (p[i * 2] % IRQS_PER_MSI_REG ||
 521                            p[i * 2 + 1] % IRQS_PER_MSI_REG) {
 522                                pr_warn("%s: %pOF: msi available range of %u at %u is not IRQ-aligned\n",
 523                                       __func__, dev->dev.of_node,
 524                                       p[i * 2 + 1], p[i * 2]);
 525                                err = -EINVAL;
 526                                goto error_out;
 527                        }
 528
 529                        offset = p[i * 2] / IRQS_PER_MSI_REG;
 530                        count = p[i * 2 + 1] / IRQS_PER_MSI_REG;
 531
 532                        for (j = 0; j < count; j++, irq_index++) {
 533                                err = fsl_msi_setup_hwirq(msi, dev, offset + j,
 534                                                          irq_index);
 535                                if (err)
 536                                        goto error_out;
 537                        }
 538                }
 539        }
 540
 541        list_add_tail(&msi->list, &msi_head);
 542
 543        /*
 544         * Apply the MSI ops to all the controllers.
 545         * It doesn't hurt to reassign the same ops,
 546         * but bail out if we find another MSI driver.
 547         */
 548        list_for_each_entry(phb, &hose_list, list_node) {
 549                if (!phb->controller_ops.setup_msi_irqs) {
 550                        phb->controller_ops.setup_msi_irqs = fsl_setup_msi_irqs;
 551                        phb->controller_ops.teardown_msi_irqs = fsl_teardown_msi_irqs;
 552                } else if (phb->controller_ops.setup_msi_irqs != fsl_setup_msi_irqs) {
 553                        dev_err(&dev->dev, "Different MSI driver already installed!\n");
 554                        err = -ENODEV;
 555                        goto error_out;
 556                }
 557        }
 558        return 0;
 559error_out:
 560        fsl_of_msi_remove(dev);
 561        return err;
 562}
 563
 564static const struct fsl_msi_feature mpic_msi_feature = {
 565        .fsl_pic_ip = FSL_PIC_IP_MPIC,
 566        .msiir_offset = 0x140,
 567};
 568
 569static const struct fsl_msi_feature ipic_msi_feature = {
 570        .fsl_pic_ip = FSL_PIC_IP_IPIC,
 571        .msiir_offset = 0x38,
 572};
 573
 574static const struct fsl_msi_feature vmpic_msi_feature = {
 575        .fsl_pic_ip = FSL_PIC_IP_VMPIC,
 576        .msiir_offset = 0,
 577};
 578
 579static const struct of_device_id fsl_of_msi_ids[] = {
 580        {
 581                .compatible = "fsl,mpic-msi",
 582                .data = &mpic_msi_feature,
 583        },
 584        {
 585                .compatible = "fsl,mpic-msi-v4.3",
 586                .data = &mpic_msi_feature,
 587        },
 588        {
 589                .compatible = "fsl,ipic-msi",
 590                .data = &ipic_msi_feature,
 591        },
 592#ifdef CONFIG_EPAPR_PARAVIRT
 593        {
 594                .compatible = "fsl,vmpic-msi",
 595                .data = &vmpic_msi_feature,
 596        },
 597        {
 598                .compatible = "fsl,vmpic-msi-v4.3",
 599                .data = &vmpic_msi_feature,
 600        },
 601#endif
 602        {}
 603};
 604
 605static struct platform_driver fsl_of_msi_driver = {
 606        .driver = {
 607                .name = "fsl-msi",
 608                .of_match_table = fsl_of_msi_ids,
 609        },
 610        .probe = fsl_of_msi_probe,
 611        .remove = fsl_of_msi_remove,
 612};
 613
 614static __init int fsl_of_msi_init(void)
 615{
 616        return platform_driver_register(&fsl_of_msi_driver);
 617}
 618
 619subsys_initcall(fsl_of_msi_init);
 620