linux/drivers/virtio/virtio_mmio.c
<<
>>
Prefs
   1/*
   2 * Virtio memory mapped device driver
   3 *
   4 * Copyright 2011-2014, ARM Ltd.
   5 *
   6 * This module allows virtio devices to be used over a virtual, memory mapped
   7 * platform device.
   8 *
   9 * The guest device(s) may be instantiated in one of three equivalent ways:
  10 *
  11 * 1. Static platform device in board's code, eg.:
  12 *
  13 *      static struct platform_device v2m_virtio_device = {
  14 *              .name = "virtio-mmio",
  15 *              .id = -1,
  16 *              .num_resources = 2,
  17 *              .resource = (struct resource []) {
  18 *                      {
  19 *                              .start = 0x1001e000,
  20 *                              .end = 0x1001e0ff,
  21 *                              .flags = IORESOURCE_MEM,
  22 *                      }, {
  23 *                              .start = 42 + 32,
  24 *                              .end = 42 + 32,
  25 *                              .flags = IORESOURCE_IRQ,
  26 *                      },
  27 *              }
  28 *      };
  29 *
  30 * 2. Device Tree node, eg.:
  31 *
  32 *              virtio_block@1e000 {
  33 *                      compatible = "virtio,mmio";
  34 *                      reg = <0x1e000 0x100>;
  35 *                      interrupts = <42>;
  36 *              }
  37 *
  38 * 3. Kernel module (or command line) parameter. Can be used more than once -
  39 *    one device will be created for each one. Syntax:
  40 *
  41 *              [virtio_mmio.]device=<size>@<baseaddr>:<irq>[:<id>]
  42 *    where:
  43 *              <size>     := size (can use standard suffixes like K, M or G)
  44 *              <baseaddr> := physical base address
  45 *              <irq>      := interrupt number (as passed to request_irq())
  46 *              <id>       := (optional) platform device id
  47 *    eg.:
  48 *              virtio_mmio.device=0x100@0x100b0000:48 \
  49 *                              virtio_mmio.device=1K@0x1001e000:74
  50 *
  51 *
  52 *
  53 * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
  54 *
  55 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  56 * See the COPYING file in the top-level directory.
  57 */
  58
  59#define pr_fmt(fmt) "virtio-mmio: " fmt
  60
  61#include <linux/acpi.h>
  62#include <linux/dma-mapping.h>
  63#include <linux/highmem.h>
  64#include <linux/interrupt.h>
  65#include <linux/io.h>
  66#include <linux/list.h>
  67#include <linux/module.h>
  68#include <linux/platform_device.h>
  69#include <linux/slab.h>
  70#include <linux/spinlock.h>
  71#include <linux/virtio.h>
  72#include <linux/virtio_config.h>
  73#include <uapi/linux/virtio_mmio.h>
  74#include <linux/virtio_ring.h>
  75
  76
  77
  78/* The alignment to use between consumer and producer parts of vring.
  79 * Currently hardcoded to the page size. */
  80#define VIRTIO_MMIO_VRING_ALIGN         PAGE_SIZE
  81
  82
  83
  84#define to_virtio_mmio_device(_plat_dev) \
  85        container_of(_plat_dev, struct virtio_mmio_device, vdev)
  86
  87struct virtio_mmio_device {
  88        struct virtio_device vdev;
  89        struct platform_device *pdev;
  90
  91        void __iomem *base;
  92        unsigned long version;
  93
  94        /* a list of queues so we can dispatch IRQs */
  95        spinlock_t lock;
  96        struct list_head virtqueues;
  97};
  98
  99struct virtio_mmio_vq_info {
 100        /* the actual virtqueue */
 101        struct virtqueue *vq;
 102
 103        /* the list node for the virtqueues list */
 104        struct list_head node;
 105};
 106
 107
 108
 109/* Configuration interface */
 110
 111static u64 vm_get_features(struct virtio_device *vdev)
 112{
 113        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 114        u64 features;
 115
 116        writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
 117        features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
 118        features <<= 32;
 119
 120        writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
 121        features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
 122
 123        return features;
 124}
 125
 126static int vm_finalize_features(struct virtio_device *vdev)
 127{
 128        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 129
 130        /* Give virtio_ring a chance to accept features. */
 131        vring_transport_features(vdev);
 132
 133        /* Make sure there is are no mixed devices */
 134        if (vm_dev->version == 2 &&
 135                        !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
 136                dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
 137                return -EINVAL;
 138        }
 139
 140        writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
 141        writel((u32)(vdev->features >> 32),
 142                        vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
 143
 144        writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
 145        writel((u32)vdev->features,
 146                        vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
 147
 148        return 0;
 149}
 150
 151static void vm_get(struct virtio_device *vdev, unsigned offset,
 152                   void *buf, unsigned len)
 153{
 154        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 155        void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
 156        u8 b;
 157        __le16 w;
 158        __le32 l;
 159
 160        if (vm_dev->version == 1) {
 161                u8 *ptr = buf;
 162                int i;
 163
 164                for (i = 0; i < len; i++)
 165                        ptr[i] = readb(base + offset + i);
 166                return;
 167        }
 168
 169        switch (len) {
 170        case 1:
 171                b = readb(base + offset);
 172                memcpy(buf, &b, sizeof b);
 173                break;
 174        case 2:
 175                w = cpu_to_le16(readw(base + offset));
 176                memcpy(buf, &w, sizeof w);
 177                break;
 178        case 4:
 179                l = cpu_to_le32(readl(base + offset));
 180                memcpy(buf, &l, sizeof l);
 181                break;
 182        case 8:
 183                l = cpu_to_le32(readl(base + offset));
 184                memcpy(buf, &l, sizeof l);
 185                l = cpu_to_le32(ioread32(base + offset + sizeof l));
 186                memcpy(buf + sizeof l, &l, sizeof l);
 187                break;
 188        default:
 189                BUG();
 190        }
 191}
 192
 193static void vm_set(struct virtio_device *vdev, unsigned offset,
 194                   const void *buf, unsigned len)
 195{
 196        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 197        void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
 198        u8 b;
 199        __le16 w;
 200        __le32 l;
 201
 202        if (vm_dev->version == 1) {
 203                const u8 *ptr = buf;
 204                int i;
 205
 206                for (i = 0; i < len; i++)
 207                        writeb(ptr[i], base + offset + i);
 208
 209                return;
 210        }
 211
 212        switch (len) {
 213        case 1:
 214                memcpy(&b, buf, sizeof b);
 215                writeb(b, base + offset);
 216                break;
 217        case 2:
 218                memcpy(&w, buf, sizeof w);
 219                writew(le16_to_cpu(w), base + offset);
 220                break;
 221        case 4:
 222                memcpy(&l, buf, sizeof l);
 223                writel(le32_to_cpu(l), base + offset);
 224                break;
 225        case 8:
 226                memcpy(&l, buf, sizeof l);
 227                writel(le32_to_cpu(l), base + offset);
 228                memcpy(&l, buf + sizeof l, sizeof l);
 229                writel(le32_to_cpu(l), base + offset + sizeof l);
 230                break;
 231        default:
 232                BUG();
 233        }
 234}
 235
 236static u32 vm_generation(struct virtio_device *vdev)
 237{
 238        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 239
 240        if (vm_dev->version == 1)
 241                return 0;
 242        else
 243                return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
 244}
 245
 246static u8 vm_get_status(struct virtio_device *vdev)
 247{
 248        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 249
 250        return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
 251}
 252
 253static void vm_set_status(struct virtio_device *vdev, u8 status)
 254{
 255        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 256
 257        /* We should never be setting status to 0. */
 258        BUG_ON(status == 0);
 259
 260        writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
 261}
 262
 263static void vm_reset(struct virtio_device *vdev)
 264{
 265        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 266
 267        /* 0 status means a reset. */
 268        writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
 269}
 270
 271
 272
 273/* Transport interface */
 274
 275/* the notify function used when creating a virt queue */
 276static bool vm_notify(struct virtqueue *vq)
 277{
 278        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
 279
 280        /* We write the queue's selector into the notification register to
 281         * signal the other end */
 282        writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
 283        return true;
 284}
 285
 286/* Notify all virtqueues on an interrupt. */
 287static irqreturn_t vm_interrupt(int irq, void *opaque)
 288{
 289        struct virtio_mmio_device *vm_dev = opaque;
 290        struct virtio_mmio_vq_info *info;
 291        unsigned long status;
 292        unsigned long flags;
 293        irqreturn_t ret = IRQ_NONE;
 294
 295        /* Read and acknowledge interrupts */
 296        status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
 297        writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
 298
 299        if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
 300                virtio_config_changed(&vm_dev->vdev);
 301                ret = IRQ_HANDLED;
 302        }
 303
 304        if (likely(status & VIRTIO_MMIO_INT_VRING)) {
 305                spin_lock_irqsave(&vm_dev->lock, flags);
 306                list_for_each_entry(info, &vm_dev->virtqueues, node)
 307                        ret |= vring_interrupt(irq, info->vq);
 308                spin_unlock_irqrestore(&vm_dev->lock, flags);
 309        }
 310
 311        return ret;
 312}
 313
 314
 315
 316static void vm_del_vq(struct virtqueue *vq)
 317{
 318        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
 319        struct virtio_mmio_vq_info *info = vq->priv;
 320        unsigned long flags;
 321        unsigned int index = vq->index;
 322
 323        spin_lock_irqsave(&vm_dev->lock, flags);
 324        list_del(&info->node);
 325        spin_unlock_irqrestore(&vm_dev->lock, flags);
 326
 327        /* Select and deactivate the queue */
 328        writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
 329        if (vm_dev->version == 1) {
 330                writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
 331        } else {
 332                writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
 333                WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
 334        }
 335
 336        vring_del_virtqueue(vq);
 337
 338        kfree(info);
 339}
 340
 341static void vm_del_vqs(struct virtio_device *vdev)
 342{
 343        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 344        struct virtqueue *vq, *n;
 345
 346        list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 347                vm_del_vq(vq);
 348
 349        free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
 350}
 351
 352static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
 353                                  void (*callback)(struct virtqueue *vq),
 354                                  const char *name, bool ctx)
 355{
 356        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 357        struct virtio_mmio_vq_info *info;
 358        struct virtqueue *vq;
 359        unsigned long flags;
 360        unsigned int num;
 361        int err;
 362
 363        if (!name)
 364                return NULL;
 365
 366        /* Select the queue we're interested in */
 367        writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
 368
 369        /* Queue shouldn't already be set up. */
 370        if (readl(vm_dev->base + (vm_dev->version == 1 ?
 371                        VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
 372                err = -ENOENT;
 373                goto error_available;
 374        }
 375
 376        /* Allocate and fill out our active queue description */
 377        info = kmalloc(sizeof(*info), GFP_KERNEL);
 378        if (!info) {
 379                err = -ENOMEM;
 380                goto error_kmalloc;
 381        }
 382
 383        num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
 384        if (num == 0) {
 385                err = -ENOENT;
 386                goto error_new_virtqueue;
 387        }
 388
 389        /* Create the vring */
 390        vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
 391                                 true, true, ctx, vm_notify, callback, name);
 392        if (!vq) {
 393                err = -ENOMEM;
 394                goto error_new_virtqueue;
 395        }
 396
 397        /* Activate the queue */
 398        writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
 399        if (vm_dev->version == 1) {
 400                writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
 401                writel(virtqueue_get_desc_addr(vq) >> PAGE_SHIFT,
 402                                vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
 403        } else {
 404                u64 addr;
 405
 406                addr = virtqueue_get_desc_addr(vq);
 407                writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
 408                writel((u32)(addr >> 32),
 409                                vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
 410
 411                addr = virtqueue_get_avail_addr(vq);
 412                writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
 413                writel((u32)(addr >> 32),
 414                                vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
 415
 416                addr = virtqueue_get_used_addr(vq);
 417                writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
 418                writel((u32)(addr >> 32),
 419                                vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
 420
 421                writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
 422        }
 423
 424        vq->priv = info;
 425        info->vq = vq;
 426
 427        spin_lock_irqsave(&vm_dev->lock, flags);
 428        list_add(&info->node, &vm_dev->virtqueues);
 429        spin_unlock_irqrestore(&vm_dev->lock, flags);
 430
 431        return vq;
 432
 433error_new_virtqueue:
 434        if (vm_dev->version == 1) {
 435                writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
 436        } else {
 437                writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
 438                WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
 439        }
 440        kfree(info);
 441error_kmalloc:
 442error_available:
 443        return ERR_PTR(err);
 444}
 445
 446static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 447                       struct virtqueue *vqs[],
 448                       vq_callback_t *callbacks[],
 449                       const char * const names[],
 450                       const bool *ctx,
 451                       struct irq_affinity *desc)
 452{
 453        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 454        unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
 455        int i, err;
 456
 457        err = request_irq(irq, vm_interrupt, IRQF_SHARED,
 458                        dev_name(&vdev->dev), vm_dev);
 459        if (err)
 460                return err;
 461
 462        for (i = 0; i < nvqs; ++i) {
 463                vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i],
 464                                     ctx ? ctx[i] : false);
 465                if (IS_ERR(vqs[i])) {
 466                        vm_del_vqs(vdev);
 467                        return PTR_ERR(vqs[i]);
 468                }
 469        }
 470
 471        return 0;
 472}
 473
 474static const char *vm_bus_name(struct virtio_device *vdev)
 475{
 476        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 477
 478        return vm_dev->pdev->name;
 479}
 480
 481static const struct virtio_config_ops virtio_mmio_config_ops = {
 482        .get            = vm_get,
 483        .set            = vm_set,
 484        .generation     = vm_generation,
 485        .get_status     = vm_get_status,
 486        .set_status     = vm_set_status,
 487        .reset          = vm_reset,
 488        .find_vqs       = vm_find_vqs,
 489        .del_vqs        = vm_del_vqs,
 490        .get_features   = vm_get_features,
 491        .finalize_features = vm_finalize_features,
 492        .bus_name       = vm_bus_name,
 493};
 494
 495
 496static void virtio_mmio_release_dev(struct device *_d)
 497{
 498        struct virtio_device *vdev =
 499                        container_of(_d, struct virtio_device, dev);
 500        struct virtio_mmio_device *vm_dev =
 501                        container_of(vdev, struct virtio_mmio_device, vdev);
 502        struct platform_device *pdev = vm_dev->pdev;
 503
 504        devm_kfree(&pdev->dev, vm_dev);
 505}
 506
 507/* Platform device */
 508
 509static int virtio_mmio_probe(struct platform_device *pdev)
 510{
 511        struct virtio_mmio_device *vm_dev;
 512        struct resource *mem;
 513        unsigned long magic;
 514        int rc;
 515
 516        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 517        if (!mem)
 518                return -EINVAL;
 519
 520        if (!devm_request_mem_region(&pdev->dev, mem->start,
 521                        resource_size(mem), pdev->name))
 522                return -EBUSY;
 523
 524        vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
 525        if (!vm_dev)
 526                return -ENOMEM;
 527
 528        vm_dev->vdev.dev.parent = &pdev->dev;
 529        vm_dev->vdev.dev.release = virtio_mmio_release_dev;
 530        vm_dev->vdev.config = &virtio_mmio_config_ops;
 531        vm_dev->pdev = pdev;
 532        INIT_LIST_HEAD(&vm_dev->virtqueues);
 533        spin_lock_init(&vm_dev->lock);
 534
 535        vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
 536        if (vm_dev->base == NULL)
 537                return -EFAULT;
 538
 539        /* Check magic value */
 540        magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
 541        if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
 542                dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
 543                return -ENODEV;
 544        }
 545
 546        /* Check device version */
 547        vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
 548        if (vm_dev->version < 1 || vm_dev->version > 2) {
 549                dev_err(&pdev->dev, "Version %ld not supported!\n",
 550                                vm_dev->version);
 551                return -ENXIO;
 552        }
 553
 554        vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
 555        if (vm_dev->vdev.id.device == 0) {
 556                /*
 557                 * virtio-mmio device with an ID 0 is a (dummy) placeholder
 558                 * with no function. End probing now with no error reported.
 559                 */
 560                return -ENODEV;
 561        }
 562        vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
 563
 564        if (vm_dev->version == 1) {
 565                writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
 566
 567                rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
 568                /*
 569                 * In the legacy case, ensure our coherently-allocated virtio
 570                 * ring will be at an address expressable as a 32-bit PFN.
 571                 */
 572                if (!rc)
 573                        dma_set_coherent_mask(&pdev->dev,
 574                                              DMA_BIT_MASK(32 + PAGE_SHIFT));
 575        } else {
 576                rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 577        }
 578        if (rc)
 579                rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 580        if (rc)
 581                dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
 582
 583        platform_set_drvdata(pdev, vm_dev);
 584
 585        rc = register_virtio_device(&vm_dev->vdev);
 586        if (rc)
 587                put_device(&vm_dev->vdev.dev);
 588
 589        return rc;
 590}
 591
 592static int virtio_mmio_remove(struct platform_device *pdev)
 593{
 594        struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
 595        unregister_virtio_device(&vm_dev->vdev);
 596
 597        return 0;
 598}
 599
 600
 601
 602/* Devices list parameter */
 603
 604#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
 605
 606static struct device vm_cmdline_parent = {
 607        .init_name = "virtio-mmio-cmdline",
 608};
 609
 610static int vm_cmdline_parent_registered;
 611static int vm_cmdline_id;
 612
 613static int vm_cmdline_set(const char *device,
 614                const struct kernel_param *kp)
 615{
 616        int err;
 617        struct resource resources[2] = {};
 618        char *str;
 619        long long int base, size;
 620        unsigned int irq;
 621        int processed, consumed = 0;
 622        struct platform_device *pdev;
 623
 624        /* Consume "size" part of the command line parameter */
 625        size = memparse(device, &str);
 626
 627        /* Get "@<base>:<irq>[:<id>]" chunks */
 628        processed = sscanf(str, "@%lli:%u%n:%d%n",
 629                        &base, &irq, &consumed,
 630                        &vm_cmdline_id, &consumed);
 631
 632        /*
 633         * sscanf() must processes at least 2 chunks; also there
 634         * must be no extra characters after the last chunk, so
 635         * str[consumed] must be '\0'
 636         */
 637        if (processed < 2 || str[consumed])
 638                return -EINVAL;
 639
 640        resources[0].flags = IORESOURCE_MEM;
 641        resources[0].start = base;
 642        resources[0].end = base + size - 1;
 643
 644        resources[1].flags = IORESOURCE_IRQ;
 645        resources[1].start = resources[1].end = irq;
 646
 647        if (!vm_cmdline_parent_registered) {
 648                err = device_register(&vm_cmdline_parent);
 649                if (err) {
 650                        pr_err("Failed to register parent device!\n");
 651                        return err;
 652                }
 653                vm_cmdline_parent_registered = 1;
 654        }
 655
 656        pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
 657                       vm_cmdline_id,
 658                       (unsigned long long)resources[0].start,
 659                       (unsigned long long)resources[0].end,
 660                       (int)resources[1].start);
 661
 662        pdev = platform_device_register_resndata(&vm_cmdline_parent,
 663                        "virtio-mmio", vm_cmdline_id++,
 664                        resources, ARRAY_SIZE(resources), NULL, 0);
 665
 666        return PTR_ERR_OR_ZERO(pdev);
 667}
 668
 669static int vm_cmdline_get_device(struct device *dev, void *data)
 670{
 671        char *buffer = data;
 672        unsigned int len = strlen(buffer);
 673        struct platform_device *pdev = to_platform_device(dev);
 674
 675        snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
 676                        pdev->resource[0].end - pdev->resource[0].start + 1ULL,
 677                        (unsigned long long)pdev->resource[0].start,
 678                        (unsigned long long)pdev->resource[1].start,
 679                        pdev->id);
 680        return 0;
 681}
 682
 683static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
 684{
 685        buffer[0] = '\0';
 686        device_for_each_child(&vm_cmdline_parent, buffer,
 687                        vm_cmdline_get_device);
 688        return strlen(buffer) + 1;
 689}
 690
 691static const struct kernel_param_ops vm_cmdline_param_ops = {
 692        .set = vm_cmdline_set,
 693        .get = vm_cmdline_get,
 694};
 695
 696device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
 697
 698static int vm_unregister_cmdline_device(struct device *dev,
 699                void *data)
 700{
 701        platform_device_unregister(to_platform_device(dev));
 702
 703        return 0;
 704}
 705
 706static void vm_unregister_cmdline_devices(void)
 707{
 708        if (vm_cmdline_parent_registered) {
 709                device_for_each_child(&vm_cmdline_parent, NULL,
 710                                vm_unregister_cmdline_device);
 711                device_unregister(&vm_cmdline_parent);
 712                vm_cmdline_parent_registered = 0;
 713        }
 714}
 715
 716#else
 717
 718static void vm_unregister_cmdline_devices(void)
 719{
 720}
 721
 722#endif
 723
 724/* Platform driver */
 725
 726static const struct of_device_id virtio_mmio_match[] = {
 727        { .compatible = "virtio,mmio", },
 728        {},
 729};
 730MODULE_DEVICE_TABLE(of, virtio_mmio_match);
 731
 732#ifdef CONFIG_ACPI
 733static const struct acpi_device_id virtio_mmio_acpi_match[] = {
 734        { "LNRO0005", },
 735        { }
 736};
 737MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
 738#endif
 739
 740static struct platform_driver virtio_mmio_driver = {
 741        .probe          = virtio_mmio_probe,
 742        .remove         = virtio_mmio_remove,
 743        .driver         = {
 744                .name   = "virtio-mmio",
 745                .of_match_table = virtio_mmio_match,
 746                .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
 747        },
 748};
 749
 750static int __init virtio_mmio_init(void)
 751{
 752        return platform_driver_register(&virtio_mmio_driver);
 753}
 754
 755static void __exit virtio_mmio_exit(void)
 756{
 757        platform_driver_unregister(&virtio_mmio_driver);
 758        vm_unregister_cmdline_devices();
 759}
 760
 761module_init(virtio_mmio_init);
 762module_exit(virtio_mmio_exit);
 763
 764MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
 765MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
 766MODULE_LICENSE("GPL");
 767