drivers/virtio/virtio_mmio.c

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