1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Virtio memory mapped device driver 4 * 5 * Copyright 2011-2014, ARM Ltd. 6 * 7 * This module allows virtio devices to be used over a virtual, memory mapped 8 * platform device. 9 * 10 * The guest device(s) may be instantiated in one of three equivalent ways: 11 * 12 * 1. Static platform device in board's code, eg.: 13 * 14 * static struct platform_device v2m_virtio_device = { 15 * .name = "virtio-mmio", 16 * .id = -1, 17 * .num_resources = 2, 18 * .resource = (struct resource []) { 19 * { 20 * .start = 0x1001e000, 21 * .end = 0x1001e0ff, 22 * .flags = IORESOURCE_MEM, 23 * }, { 24 * .start = 42 + 32, 25 * .end = 42 + 32, 26 * .flags = IORESOURCE_IRQ, 27 * }, 28 * } 29 * }; 30 * 31 * 2. Device Tree node, eg.: 32 * 33 * virtio_block@1e000 { 34 * compatible = "virtio,mmio"; 35 * reg = <0x1e000 0x100>; 36 * interrupts = <42>; 37 * } 38 * 39 * 3. Kernel module (or command line) parameter. Can be used more than once - 40 * one device will be created for each one. Syntax: 41 * 42 * [virtio_mmio.]device=<size>@<baseaddr>:<irq>[:<id>] 43 * where: 44 * <size> := size (can use standard suffixes like K, M or G) 45 * <baseaddr> := physical base address 46 * <irq> := interrupt number (as passed to request_irq()) 47 * <id> := (optional) platform device id 48 * eg.: 49 * virtio_mmio.device=0x100@0x100b0000:48 \ 50 * virtio_mmio.device=1K@0x1001e000:74 51 * 52 * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007 53 */ 54 55 #define pr_fmt(fmt) "virtio-mmio: " fmt 56 57 #include <linux/acpi.h> 58 #include <linux/dma-mapping.h> 59 #include <linux/highmem.h> 60 #include <linux/interrupt.h> 61 #include <linux/io.h> 62 #include <linux/list.h> 63 #include <linux/module.h> 64 #include <linux/platform_device.h> 65 #include <linux/slab.h> 66 #include <linux/spinlock.h> 67 #include <linux/virtio.h> 68 #include <linux/virtio_config.h> 69 #include <uapi/linux/virtio_mmio.h> 70 #include <linux/virtio_ring.h> 71 72 73 74 /* The alignment to use between consumer and producer parts of vring. 75 * Currently hardcoded to the page size. */ 76 #define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE 77 78 79 80 #define to_virtio_mmio_device(_plat_dev) \ 81 container_of(_plat_dev, struct virtio_mmio_device, vdev) 82 83 struct virtio_mmio_device { 84 struct virtio_device vdev; 85 struct platform_device *pdev; 86 87 void __iomem *base; 88 unsigned long version; 89 90 /* a list of queues so we can dispatch IRQs */ 91 spinlock_t lock; 92 struct list_head virtqueues; 93 }; 94 95 struct virtio_mmio_vq_info { 96 /* the actual virtqueue */ 97 struct virtqueue *vq; 98 99 /* the list node for the virtqueues list */ 100 struct list_head node; 101 }; 102 103 104 105 /* Configuration interface */ 106 107 static u64 vm_get_features(struct virtio_device *vdev) 108 { 109 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 110 u64 features; 111 112 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 113 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 114 features <<= 32; 115 116 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 117 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 118 119 return features; 120 } 121 122 static int vm_finalize_features(struct virtio_device *vdev) 123 { 124 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 125 126 /* Give virtio_ring a chance to accept features. */ 127 vring_transport_features(vdev); 128 129 /* Make sure there are no mixed devices */ 130 if (vm_dev->version == 2 && 131 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) { 132 dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n"); 133 return -EINVAL; 134 } 135 136 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 137 writel((u32)(vdev->features >> 32), 138 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 139 140 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 141 writel((u32)vdev->features, 142 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 143 144 return 0; 145 } 146 147 static void vm_get(struct virtio_device *vdev, unsigned int offset, 148 void *buf, unsigned int len) 149 { 150 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 151 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 152 u8 b; 153 __le16 w; 154 __le32 l; 155 156 if (vm_dev->version == 1) { 157 u8 *ptr = buf; 158 int i; 159 160 for (i = 0; i < len; i++) 161 ptr[i] = readb(base + offset + i); 162 return; 163 } 164 165 switch (len) { 166 case 1: 167 b = readb(base + offset); 168 memcpy(buf, &b, sizeof b); 169 break; 170 case 2: 171 w = cpu_to_le16(readw(base + offset)); 172 memcpy(buf, &w, sizeof w); 173 break; 174 case 4: 175 l = cpu_to_le32(readl(base + offset)); 176 memcpy(buf, &l, sizeof l); 177 break; 178 case 8: 179 l = cpu_to_le32(readl(base + offset)); 180 memcpy(buf, &l, sizeof l); 181 l = cpu_to_le32(ioread32(base + offset + sizeof l)); 182 memcpy(buf + sizeof l, &l, sizeof l); 183 break; 184 default: 185 BUG(); 186 } 187 } 188 189 static void vm_set(struct virtio_device *vdev, unsigned int offset, 190 const void *buf, unsigned int len) 191 { 192 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 193 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 194 u8 b; 195 __le16 w; 196 __le32 l; 197 198 if (vm_dev->version == 1) { 199 const u8 *ptr = buf; 200 int i; 201 202 for (i = 0; i < len; i++) 203 writeb(ptr[i], base + offset + i); 204 205 return; 206 } 207 208 switch (len) { 209 case 1: 210 memcpy(&b, buf, sizeof b); 211 writeb(b, base + offset); 212 break; 213 case 2: 214 memcpy(&w, buf, sizeof w); 215 writew(le16_to_cpu(w), base + offset); 216 break; 217 case 4: 218 memcpy(&l, buf, sizeof l); 219 writel(le32_to_cpu(l), base + offset); 220 break; 221 case 8: 222 memcpy(&l, buf, sizeof l); 223 writel(le32_to_cpu(l), base + offset); 224 memcpy(&l, buf + sizeof l, sizeof l); 225 writel(le32_to_cpu(l), base + offset + sizeof l); 226 break; 227 default: 228 BUG(); 229 } 230 } 231 232 static u32 vm_generation(struct virtio_device *vdev) 233 { 234 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 235 236 if (vm_dev->version == 1) 237 return 0; 238 else 239 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION); 240 } 241 242 static u8 vm_get_status(struct virtio_device *vdev) 243 { 244 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 245 246 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff; 247 } 248 249 static void vm_set_status(struct virtio_device *vdev, u8 status) 250 { 251 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 252 253 /* We should never be setting status to 0. */ 254 BUG_ON(status == 0); 255 256 /* 257 * Per memory-barriers.txt, wmb() is not needed to guarantee 258 * that the the cache coherent memory writes have completed 259 * before writing to the MMIO region. 260 */ 261 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS); 262 } 263 264 static void vm_reset(struct virtio_device *vdev) 265 { 266 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 267 268 /* 0 status means a reset. */ 269 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS); 270 } 271 272 273 274 /* Transport interface */ 275 276 /* the notify function used when creating a virt queue */ 277 static bool vm_notify(struct virtqueue *vq) 278 { 279 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 280 281 /* We write the queue's selector into the notification register to 282 * signal the other end */ 283 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 284 return true; 285 } 286 287 /* Notify all virtqueues on an interrupt. */ 288 static irqreturn_t vm_interrupt(int irq, void *opaque) 289 { 290 struct virtio_mmio_device *vm_dev = opaque; 291 struct virtio_mmio_vq_info *info; 292 unsigned long status; 293 unsigned long flags; 294 irqreturn_t ret = IRQ_NONE; 295 296 /* Read and acknowledge interrupts */ 297 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); 298 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); 299 300 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { 301 virtio_config_changed(&vm_dev->vdev); 302 ret = IRQ_HANDLED; 303 } 304 305 if (likely(status & VIRTIO_MMIO_INT_VRING)) { 306 spin_lock_irqsave(&vm_dev->lock, flags); 307 list_for_each_entry(info, &vm_dev->virtqueues, node) 308 ret |= vring_interrupt(irq, info->vq); 309 spin_unlock_irqrestore(&vm_dev->lock, flags); 310 } 311 312 return ret; 313 } 314 315 316 317 static void vm_del_vq(struct virtqueue *vq) 318 { 319 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 320 struct virtio_mmio_vq_info *info = vq->priv; 321 unsigned long flags; 322 unsigned int index = vq->index; 323 324 spin_lock_irqsave(&vm_dev->lock, flags); 325 list_del(&info->node); 326 spin_unlock_irqrestore(&vm_dev->lock, flags); 327 328 /* Select and deactivate the queue */ 329 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 330 if (vm_dev->version == 1) { 331 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 332 } else { 333 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 334 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 335 } 336 337 vring_del_virtqueue(vq); 338 339 kfree(info); 340 } 341 342 static void vm_del_vqs(struct virtio_device *vdev) 343 { 344 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 345 struct virtqueue *vq, *n; 346 347 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 348 vm_del_vq(vq); 349 350 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); 351 } 352 353 static void vm_synchronize_cbs(struct virtio_device *vdev) 354 { 355 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 356 357 synchronize_irq(platform_get_irq(vm_dev->pdev, 0)); 358 } 359 360 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index, 361 void (*callback)(struct virtqueue *vq), 362 const char *name, bool ctx) 363 { 364 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 365 struct virtio_mmio_vq_info *info; 366 struct virtqueue *vq; 367 unsigned long flags; 368 unsigned int num; 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 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); 392 if (num == 0) { 393 err = -ENOENT; 394 goto error_new_virtqueue; 395 } 396 397 /* Create the vring */ 398 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, 399 true, true, ctx, vm_notify, callback, name); 400 if (!vq) { 401 err = -ENOMEM; 402 goto error_new_virtqueue; 403 } 404 405 /* Activate the queue */ 406 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 407 if (vm_dev->version == 1) { 408 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 409 410 /* 411 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 412 * that doesn't fit in 32bit, fail the setup rather than 413 * pretending to be successful. 414 */ 415 if (q_pfn >> 32) { 416 dev_err(&vdev->dev, 417 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 418 0x1ULL << (32 + PAGE_SHIFT - 30)); 419 err = -E2BIG; 420 goto error_bad_pfn; 421 } 422 423 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 424 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 425 } else { 426 u64 addr; 427 428 addr = virtqueue_get_desc_addr(vq); 429 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 430 writel((u32)(addr >> 32), 431 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 432 433 addr = virtqueue_get_avail_addr(vq); 434 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 435 writel((u32)(addr >> 32), 436 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 437 438 addr = virtqueue_get_used_addr(vq); 439 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 440 writel((u32)(addr >> 32), 441 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 442 443 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 444 } 445 446 vq->priv = info; 447 info->vq = vq; 448 449 spin_lock_irqsave(&vm_dev->lock, flags); 450 list_add(&info->node, &vm_dev->virtqueues); 451 spin_unlock_irqrestore(&vm_dev->lock, flags); 452 453 return vq; 454 455 error_bad_pfn: 456 vring_del_virtqueue(vq); 457 error_new_virtqueue: 458 if (vm_dev->version == 1) { 459 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 460 } else { 461 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 462 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 463 } 464 kfree(info); 465 error_kmalloc: 466 error_available: 467 return ERR_PTR(err); 468 } 469 470 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 471 struct virtqueue *vqs[], 472 vq_callback_t *callbacks[], 473 const char * const names[], 474 const bool *ctx, 475 struct irq_affinity *desc) 476 { 477 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 478 int irq = platform_get_irq(vm_dev->pdev, 0); 479 int i, err, queue_idx = 0; 480 481 if (irq < 0) 482 return irq; 483 484 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 485 dev_name(&vdev->dev), vm_dev); 486 if (err) 487 return err; 488 489 for (i = 0; i < nvqs; ++i) { 490 if (!names[i]) { 491 vqs[i] = NULL; 492 continue; 493 } 494 495 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i], 496 ctx ? ctx[i] : false); 497 if (IS_ERR(vqs[i])) { 498 vm_del_vqs(vdev); 499 return PTR_ERR(vqs[i]); 500 } 501 } 502 503 return 0; 504 } 505 506 static const char *vm_bus_name(struct virtio_device *vdev) 507 { 508 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 509 510 return vm_dev->pdev->name; 511 } 512 513 static bool vm_get_shm_region(struct virtio_device *vdev, 514 struct virtio_shm_region *region, u8 id) 515 { 516 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 517 u64 len, addr; 518 519 /* Select the region we're interested in */ 520 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 521 522 /* Read the region size */ 523 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 524 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 525 526 region->len = len; 527 528 /* Check if region length is -1. If that's the case, the shared memory 529 * region does not exist and there is no need to proceed further. 530 */ 531 if (len == ~(u64)0) 532 return false; 533 534 /* Read the region base address */ 535 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 536 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 537 538 region->addr = addr; 539 540 return true; 541 } 542 543 static const struct virtio_config_ops virtio_mmio_config_ops = { 544 .get = vm_get, 545 .set = vm_set, 546 .generation = vm_generation, 547 .get_status = vm_get_status, 548 .set_status = vm_set_status, 549 .reset = vm_reset, 550 .find_vqs = vm_find_vqs, 551 .del_vqs = vm_del_vqs, 552 .get_features = vm_get_features, 553 .finalize_features = vm_finalize_features, 554 .bus_name = vm_bus_name, 555 .get_shm_region = vm_get_shm_region, 556 .synchronize_cbs = vm_synchronize_cbs, 557 }; 558 559 560 static void virtio_mmio_release_dev(struct device *_d) 561 { 562 struct virtio_device *vdev = 563 container_of(_d, struct virtio_device, dev); 564 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 565 struct platform_device *pdev = vm_dev->pdev; 566 567 devm_kfree(&pdev->dev, vm_dev); 568 } 569 570 /* Platform device */ 571 572 static int virtio_mmio_probe(struct platform_device *pdev) 573 { 574 struct virtio_mmio_device *vm_dev; 575 unsigned long magic; 576 int rc; 577 578 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL); 579 if (!vm_dev) 580 return -ENOMEM; 581 582 vm_dev->vdev.dev.parent = &pdev->dev; 583 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 584 vm_dev->vdev.config = &virtio_mmio_config_ops; 585 vm_dev->pdev = pdev; 586 INIT_LIST_HEAD(&vm_dev->virtqueues); 587 spin_lock_init(&vm_dev->lock); 588 589 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 590 if (IS_ERR(vm_dev->base)) 591 return PTR_ERR(vm_dev->base); 592 593 /* Check magic value */ 594 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 595 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 596 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 597 return -ENODEV; 598 } 599 600 /* Check device version */ 601 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 602 if (vm_dev->version < 1 || vm_dev->version > 2) { 603 dev_err(&pdev->dev, "Version %ld not supported!\n", 604 vm_dev->version); 605 return -ENXIO; 606 } 607 608 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 609 if (vm_dev->vdev.id.device == 0) { 610 /* 611 * virtio-mmio device with an ID 0 is a (dummy) placeholder 612 * with no function. End probing now with no error reported. 613 */ 614 return -ENODEV; 615 } 616 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 617 618 if (vm_dev->version == 1) { 619 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 620 621 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 622 /* 623 * In the legacy case, ensure our coherently-allocated virtio 624 * ring will be at an address expressable as a 32-bit PFN. 625 */ 626 if (!rc) 627 dma_set_coherent_mask(&pdev->dev, 628 DMA_BIT_MASK(32 + PAGE_SHIFT)); 629 } else { 630 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 631 } 632 if (rc) 633 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 634 if (rc) 635 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 636 637 platform_set_drvdata(pdev, vm_dev); 638 639 rc = register_virtio_device(&vm_dev->vdev); 640 if (rc) 641 put_device(&vm_dev->vdev.dev); 642 643 return rc; 644 } 645 646 static int virtio_mmio_remove(struct platform_device *pdev) 647 { 648 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 649 unregister_virtio_device(&vm_dev->vdev); 650 651 return 0; 652 } 653 654 655 656 /* Devices list parameter */ 657 658 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 659 660 static struct device vm_cmdline_parent = { 661 .init_name = "virtio-mmio-cmdline", 662 }; 663 664 static int vm_cmdline_parent_registered; 665 static int vm_cmdline_id; 666 667 static int vm_cmdline_set(const char *device, 668 const struct kernel_param *kp) 669 { 670 int err; 671 struct resource resources[2] = {}; 672 char *str; 673 long long base, size; 674 unsigned int irq; 675 int processed, consumed = 0; 676 struct platform_device *pdev; 677 678 /* Consume "size" part of the command line parameter */ 679 size = memparse(device, &str); 680 681 /* Get "@<base>:<irq>[:<id>]" chunks */ 682 processed = sscanf(str, "@%lli:%u%n:%d%n", 683 &base, &irq, &consumed, 684 &vm_cmdline_id, &consumed); 685 686 /* 687 * sscanf() must process at least 2 chunks; also there 688 * must be no extra characters after the last chunk, so 689 * str[consumed] must be '\0' 690 */ 691 if (processed < 2 || str[consumed] || irq == 0) 692 return -EINVAL; 693 694 resources[0].flags = IORESOURCE_MEM; 695 resources[0].start = base; 696 resources[0].end = base + size - 1; 697 698 resources[1].flags = IORESOURCE_IRQ; 699 resources[1].start = resources[1].end = irq; 700 701 if (!vm_cmdline_parent_registered) { 702 err = device_register(&vm_cmdline_parent); 703 if (err) { 704 pr_err("Failed to register parent device!\n"); 705 return err; 706 } 707 vm_cmdline_parent_registered = 1; 708 } 709 710 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", 711 vm_cmdline_id, 712 (unsigned long long)resources[0].start, 713 (unsigned long long)resources[0].end, 714 (int)resources[1].start); 715 716 pdev = platform_device_register_resndata(&vm_cmdline_parent, 717 "virtio-mmio", vm_cmdline_id++, 718 resources, ARRAY_SIZE(resources), NULL, 0); 719 720 return PTR_ERR_OR_ZERO(pdev); 721 } 722 723 static int vm_cmdline_get_device(struct device *dev, void *data) 724 { 725 char *buffer = data; 726 unsigned int len = strlen(buffer); 727 struct platform_device *pdev = to_platform_device(dev); 728 729 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", 730 pdev->resource[0].end - pdev->resource[0].start + 1ULL, 731 (unsigned long long)pdev->resource[0].start, 732 (unsigned long long)pdev->resource[1].start, 733 pdev->id); 734 return 0; 735 } 736 737 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 738 { 739 buffer[0] = '\0'; 740 device_for_each_child(&vm_cmdline_parent, buffer, 741 vm_cmdline_get_device); 742 return strlen(buffer) + 1; 743 } 744 745 static const struct kernel_param_ops vm_cmdline_param_ops = { 746 .set = vm_cmdline_set, 747 .get = vm_cmdline_get, 748 }; 749 750 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 751 752 static int vm_unregister_cmdline_device(struct device *dev, 753 void *data) 754 { 755 platform_device_unregister(to_platform_device(dev)); 756 757 return 0; 758 } 759 760 static void vm_unregister_cmdline_devices(void) 761 { 762 if (vm_cmdline_parent_registered) { 763 device_for_each_child(&vm_cmdline_parent, NULL, 764 vm_unregister_cmdline_device); 765 device_unregister(&vm_cmdline_parent); 766 vm_cmdline_parent_registered = 0; 767 } 768 } 769 770 #else 771 772 static void vm_unregister_cmdline_devices(void) 773 { 774 } 775 776 #endif 777 778 /* Platform driver */ 779 780 static const struct of_device_id virtio_mmio_match[] = { 781 { .compatible = "virtio,mmio", }, 782 {}, 783 }; 784 MODULE_DEVICE_TABLE(of, virtio_mmio_match); 785 786 #ifdef CONFIG_ACPI 787 static const struct acpi_device_id virtio_mmio_acpi_match[] = { 788 { "LNRO0005", }, 789 { } 790 }; 791 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 792 #endif 793 794 static struct platform_driver virtio_mmio_driver = { 795 .probe = virtio_mmio_probe, 796 .remove = virtio_mmio_remove, 797 .driver = { 798 .name = "virtio-mmio", 799 .of_match_table = virtio_mmio_match, 800 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 801 }, 802 }; 803 804 static int __init virtio_mmio_init(void) 805 { 806 return platform_driver_register(&virtio_mmio_driver); 807 } 808 809 static void __exit virtio_mmio_exit(void) 810 { 811 platform_driver_unregister(&virtio_mmio_driver); 812 vm_unregister_cmdline_devices(); 813 } 814 815 module_init(virtio_mmio_init); 816 module_exit(virtio_mmio_exit); 817 818 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 819 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 820 MODULE_LICENSE("GPL"); 821