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/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
  87 struct 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
  99 struct 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
 111 static 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
 126 static 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
 151 static 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
 193 static 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
 236 static 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
 246 static 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
 253 static 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
 263 static 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 */
 276 static 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. */
 287 static 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
 316 static 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
 341 static 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
 352 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
 353                                   void (*callback)(struct virtqueue *vq),
 354                                   const char *name)
 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, 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
 433 error_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);
 441 error_kmalloc:
 442 error_available:
 443         return ERR_PTR(err);
 444 }
 445
 446 static 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                        struct irq_affinity *desc)
 451 {
 452         struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 453         unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
 454         int i, err;
 455
 456         err = request_irq(irq, vm_interrupt, IRQF_SHARED,
 457                         dev_name(&vdev->dev), vm_dev);
 458         if (err)
 459                 return err;
 460
 461         for (i = 0; i < nvqs; ++i) {
 462                 vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i]);
 463                 if (IS_ERR(vqs[i])) {
 464                         vm_del_vqs(vdev);
 465                         return PTR_ERR(vqs[i]);
 466                 }
 467         }
 468
 469         return 0;
 470 }
 471
 472 static const char *vm_bus_name(struct virtio_device *vdev)
 473 {
 474         struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 475
 476         return vm_dev->pdev->name;
 477 }
 478
 479 static const struct virtio_config_ops virtio_mmio_config_ops = {
 480         .get            = vm_get,
 481         .set            = vm_set,
 482         .generation     = vm_generation,
 483         .get_status     = vm_get_status,
 484         .set_status     = vm_set_status,
 485         .reset          = vm_reset,
 486         .find_vqs       = vm_find_vqs,
 487         .del_vqs        = vm_del_vqs,
 488         .get_features   = vm_get_features,
 489         .finalize_features = vm_finalize_features,
 490         .bus_name       = vm_bus_name,
 491 };
 492
 493
 494 static void virtio_mmio_release_dev_empty(struct device *_d) {}
 495
 496 /* Platform device */
 497
 498 static int virtio_mmio_probe(struct platform_device *pdev)
 499 {
 500         struct virtio_mmio_device *vm_dev;
 501         struct resource *mem;
 502         unsigned long magic;
 503         int rc;
 504
 505         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 506         if (!mem)
 507                 return -EINVAL;
 508
 509         if (!devm_request_mem_region(&pdev->dev, mem->start,
 510                         resource_size(mem), pdev->name))
 511                 return -EBUSY;
 512
 513         vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
 514         if (!vm_dev)
 515                 return  -ENOMEM;
 516
 517         vm_dev->vdev.dev.parent = &pdev->dev;
 518         vm_dev->vdev.dev.release = virtio_mmio_release_dev_empty;
 519         vm_dev->vdev.config = &virtio_mmio_config_ops;
 520         vm_dev->pdev = pdev;
 521         INIT_LIST_HEAD(&vm_dev->virtqueues);
 522         spin_lock_init(&vm_dev->lock);
 523
 524         vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
 525         if (vm_dev->base == NULL)
 526                 return -EFAULT;
 527
 528         /* Check magic value */
 529         magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
 530         if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
 531                 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
 532                 return -ENODEV;
 533         }
 534
 535         /* Check device version */
 536         vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
 537         if (vm_dev->version < 1 || vm_dev->version > 2) {
 538                 dev_err(&pdev->dev, "Version %ld not supported!\n",
 539                                 vm_dev->version);
 540                 return -ENXIO;
 541         }
 542
 543         vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
 544         if (vm_dev->vdev.id.device == 0) {
 545                 /*
 546                  * virtio-mmio device with an ID 0 is a (dummy) placeholder
 547                  * with no function. End probing now with no error reported.
 548                  */
 549                 return -ENODEV;
 550         }
 551         vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
 552
 553         if (vm_dev->version == 1) {
 554                 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
 555
 556                 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
 557                 /*
 558                  * In the legacy case, ensure our coherently-allocated virtio
 559                  * ring will be at an address expressable as a 32-bit PFN.
 560                  */
 561                 if (!rc)
 562                         dma_set_coherent_mask(&pdev->dev,
 563                                               DMA_BIT_MASK(32 + PAGE_SHIFT));
 564         } else {
 565                 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 566         }
 567         if (rc)
 568                 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 569         if (rc)
 570                 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
 571
 572         platform_set_drvdata(pdev, vm_dev);
 573
 574         return register_virtio_device(&vm_dev->vdev);
 575 }
 576
 577 static int virtio_mmio_remove(struct platform_device *pdev)
 578 {
 579         struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
 580
 581         unregister_virtio_device(&vm_dev->vdev);
 582
 583         return 0;
 584 }
 585
 586
 587
 588 /* Devices list parameter */
 589
 590 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
 591
 592 static struct device vm_cmdline_parent = {
 593         .init_name = "virtio-mmio-cmdline",
 594 };
 595
 596 static int vm_cmdline_parent_registered;
 597 static int vm_cmdline_id;
 598
 599 static int vm_cmdline_set(const char *device,
 600                 const struct kernel_param *kp)
 601 {
 602         int err;
 603         struct resource resources[2] = {};
 604         char *str;
 605         long long int base, size;
 606         unsigned int irq;
 607         int processed, consumed = 0;
 608         struct platform_device *pdev;
 609
 610         /* Consume "size" part of the command line parameter */
 611         size = memparse(device, &str);
 612
 613         /* Get "@<base>:<irq>[:<id>]" chunks */
 614         processed = sscanf(str, "@%lli:%u%n:%d%n",
 615                         &base, &irq, &consumed,
 616                         &vm_cmdline_id, &consumed);
 617
 618         /*
 619          * sscanf() must processes at least 2 chunks; also there
 620          * must be no extra characters after the last chunk, so
 621          * str[consumed] must be '\0'
 622          */
 623         if (processed < 2 || str[consumed])
 624                 return -EINVAL;
 625
 626         resources[0].flags = IORESOURCE_MEM;
 627         resources[0].start = base;
 628         resources[0].end = base + size - 1;
 629
 630         resources[1].flags = IORESOURCE_IRQ;
 631         resources[1].start = resources[1].end = irq;
 632
 633         if (!vm_cmdline_parent_registered) {
 634                 err = device_register(&vm_cmdline_parent);
 635                 if (err) {
 636                         pr_err("Failed to register parent device!\n");
 637                         return err;
 638                 }
 639                 vm_cmdline_parent_registered = 1;
 640         }
 641
 642         pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
 643                        vm_cmdline_id,
 644                        (unsigned long long)resources[0].start,
 645                        (unsigned long long)resources[0].end,
 646                        (int)resources[1].start);
 647
 648         pdev = platform_device_register_resndata(&vm_cmdline_parent,
 649                         "virtio-mmio", vm_cmdline_id++,
 650                         resources, ARRAY_SIZE(resources), NULL, 0);
 651         if (IS_ERR(pdev))
 652                 return PTR_ERR(pdev);
 653
 654         return 0;
 655 }
 656
 657 static int vm_cmdline_get_device(struct device *dev, void *data)
 658 {
 659         char *buffer = data;
 660         unsigned int len = strlen(buffer);
 661         struct platform_device *pdev = to_platform_device(dev);
 662
 663         snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
 664                         pdev->resource[0].end - pdev->resource[0].start + 1ULL,
 665                         (unsigned long long)pdev->resource[0].start,
 666                         (unsigned long long)pdev->resource[1].start,
 667                         pdev->id);
 668         return 0;
 669 }
 670
 671 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
 672 {
 673         buffer[0] = '\0';
 674         device_for_each_child(&vm_cmdline_parent, buffer,
 675                         vm_cmdline_get_device);
 676         return strlen(buffer) + 1;
 677 }
 678
 679 static const struct kernel_param_ops vm_cmdline_param_ops = {
 680         .set = vm_cmdline_set,
 681         .get = vm_cmdline_get,
 682 };
 683
 684 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
 685
 686 static int vm_unregister_cmdline_device(struct device *dev,
 687                 void *data)
 688 {
 689         platform_device_unregister(to_platform_device(dev));
 690
 691         return 0;
 692 }
 693
 694 static void vm_unregister_cmdline_devices(void)
 695 {
 696         if (vm_cmdline_parent_registered) {
 697                 device_for_each_child(&vm_cmdline_parent, NULL,
 698                                 vm_unregister_cmdline_device);
 699                 device_unregister(&vm_cmdline_parent);
 700                 vm_cmdline_parent_registered = 0;
 701         }
 702 }
 703
 704 #else
 705
 706 static void vm_unregister_cmdline_devices(void)
 707 {
 708 }
 709
 710 #endif
 711
 712 /* Platform driver */
 713
 714 static struct of_device_id virtio_mmio_match[] = {
 715         { .compatible = "virtio,mmio", },
 716         {},
 717 };
 718 MODULE_DEVICE_TABLE(of, virtio_mmio_match);
 719
 720 #ifdef CONFIG_ACPI
 721 static const struct acpi_device_id virtio_mmio_acpi_match[] = {
 722         { "LNRO0005", },
 723         { }
 724 };
 725 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
 726 #endif
 727
 728 static struct platform_driver virtio_mmio_driver = {
 729         .probe          = virtio_mmio_probe,
 730         .remove         = virtio_mmio_remove,
 731         .driver         = {
 732                 .name   = "virtio-mmio",
 733                 .of_match_table = virtio_mmio_match,
 734                 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
 735         },
 736 };
 737
 738 static int __init virtio_mmio_init(void)
 739 {
 740         return platform_driver_register(&virtio_mmio_driver);
 741 }
 742
 743 static void __exit virtio_mmio_exit(void)
 744 {
 745         platform_driver_unregister(&virtio_mmio_driver);
 746         vm_unregister_cmdline_devices();
 747 }
 748
 749 module_init(virtio_mmio_init);
 750 module_exit(virtio_mmio_exit);
 751
 752 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
 753 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
 754 MODULE_LICENSE("GPL");