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/pm.h> 66 #include <linux/slab.h> 67 #include <linux/spinlock.h> 68 #include <linux/virtio.h> 69 #include <linux/virtio_config.h> 70 #include <uapi/linux/virtio_mmio.h> 71 #include <linux/virtio_ring.h> 72 73 74 75 /* The alignment to use between consumer and producer parts of vring. 76 * Currently hardcoded to the page size. */ 77 #define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE 78 79 80 81 #define to_virtio_mmio_device(_plat_dev) \ 82 container_of(_plat_dev, struct virtio_mmio_device, vdev) 83 84 struct virtio_mmio_device { 85 struct virtio_device vdev; 86 struct platform_device *pdev; 87 88 void __iomem *base; 89 unsigned long version; 90 91 /* a list of queues so we can dispatch IRQs */ 92 spinlock_t lock; 93 struct list_head virtqueues; 94 }; 95 96 struct virtio_mmio_vq_info { 97 /* the actual virtqueue */ 98 struct virtqueue *vq; 99 100 /* the list node for the virtqueues list */ 101 struct list_head node; 102 }; 103 104 105 106 /* Configuration interface */ 107 108 static u64 vm_get_features(struct virtio_device *vdev) 109 { 110 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 111 u64 features; 112 113 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 114 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 115 features <<= 32; 116 117 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 118 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 119 120 return features; 121 } 122 123 static int vm_finalize_features(struct virtio_device *vdev) 124 { 125 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 126 127 /* Give virtio_ring a chance to accept features. */ 128 vring_transport_features(vdev); 129 130 /* Make sure there are no mixed devices */ 131 if (vm_dev->version == 2 && 132 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) { 133 dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n"); 134 return -EINVAL; 135 } 136 137 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 138 writel((u32)(vdev->features >> 32), 139 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 140 141 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 142 writel((u32)vdev->features, 143 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 144 145 return 0; 146 } 147 148 static void vm_get(struct virtio_device *vdev, unsigned int offset, 149 void *buf, unsigned int len) 150 { 151 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 152 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 153 u8 b; 154 __le16 w; 155 __le32 l; 156 157 if (vm_dev->version == 1) { 158 u8 *ptr = buf; 159 int i; 160 161 for (i = 0; i < len; i++) 162 ptr[i] = readb(base + offset + i); 163 return; 164 } 165 166 switch (len) { 167 case 1: 168 b = readb(base + offset); 169 memcpy(buf, &b, sizeof b); 170 break; 171 case 2: 172 w = cpu_to_le16(readw(base + offset)); 173 memcpy(buf, &w, sizeof w); 174 break; 175 case 4: 176 l = cpu_to_le32(readl(base + offset)); 177 memcpy(buf, &l, sizeof l); 178 break; 179 case 8: 180 l = cpu_to_le32(readl(base + offset)); 181 memcpy(buf, &l, sizeof l); 182 l = cpu_to_le32(ioread32(base + offset + sizeof l)); 183 memcpy(buf + sizeof l, &l, sizeof l); 184 break; 185 default: 186 BUG(); 187 } 188 } 189 190 static void vm_set(struct virtio_device *vdev, unsigned int offset, 191 const void *buf, unsigned int len) 192 { 193 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 194 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 195 u8 b; 196 __le16 w; 197 __le32 l; 198 199 if (vm_dev->version == 1) { 200 const u8 *ptr = buf; 201 int i; 202 203 for (i = 0; i < len; i++) 204 writeb(ptr[i], base + offset + i); 205 206 return; 207 } 208 209 switch (len) { 210 case 1: 211 memcpy(&b, buf, sizeof b); 212 writeb(b, base + offset); 213 break; 214 case 2: 215 memcpy(&w, buf, sizeof w); 216 writew(le16_to_cpu(w), base + offset); 217 break; 218 case 4: 219 memcpy(&l, buf, sizeof l); 220 writel(le32_to_cpu(l), base + offset); 221 break; 222 case 8: 223 memcpy(&l, buf, sizeof l); 224 writel(le32_to_cpu(l), base + offset); 225 memcpy(&l, buf + sizeof l, sizeof l); 226 writel(le32_to_cpu(l), base + offset + sizeof l); 227 break; 228 default: 229 BUG(); 230 } 231 } 232 233 static u32 vm_generation(struct virtio_device *vdev) 234 { 235 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 236 237 if (vm_dev->version == 1) 238 return 0; 239 else 240 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION); 241 } 242 243 static u8 vm_get_status(struct virtio_device *vdev) 244 { 245 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 246 247 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff; 248 } 249 250 static void vm_set_status(struct virtio_device *vdev, u8 status) 251 { 252 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 253 254 /* We should never be setting status to 0. */ 255 BUG_ON(status == 0); 256 257 /* 258 * Per memory-barriers.txt, wmb() is not needed to guarantee 259 * that the cache coherent memory writes have completed 260 * before writing to the MMIO region. 261 */ 262 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS); 263 } 264 265 static void vm_reset(struct virtio_device *vdev) 266 { 267 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 268 269 /* 0 status means a reset. */ 270 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS); 271 } 272 273 274 275 /* Transport interface */ 276 277 /* the notify function used when creating a virt queue */ 278 static bool vm_notify(struct virtqueue *vq) 279 { 280 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 281 282 /* We write the queue's selector into the notification register to 283 * signal the other end */ 284 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 285 return true; 286 } 287 288 /* Notify all virtqueues on an interrupt. */ 289 static irqreturn_t vm_interrupt(int irq, void *opaque) 290 { 291 struct virtio_mmio_device *vm_dev = opaque; 292 struct virtio_mmio_vq_info *info; 293 unsigned long status; 294 unsigned long flags; 295 irqreturn_t ret = IRQ_NONE; 296 297 /* Read and acknowledge interrupts */ 298 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); 299 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); 300 301 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { 302 virtio_config_changed(&vm_dev->vdev); 303 ret = IRQ_HANDLED; 304 } 305 306 if (likely(status & VIRTIO_MMIO_INT_VRING)) { 307 spin_lock_irqsave(&vm_dev->lock, flags); 308 list_for_each_entry(info, &vm_dev->virtqueues, node) 309 ret |= vring_interrupt(irq, info->vq); 310 spin_unlock_irqrestore(&vm_dev->lock, flags); 311 } 312 313 return ret; 314 } 315 316 317 318 static void vm_del_vq(struct virtqueue *vq) 319 { 320 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 321 struct virtio_mmio_vq_info *info = vq->priv; 322 unsigned long flags; 323 unsigned int index = vq->index; 324 325 spin_lock_irqsave(&vm_dev->lock, flags); 326 list_del(&info->node); 327 spin_unlock_irqrestore(&vm_dev->lock, flags); 328 329 /* Select and deactivate the queue */ 330 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 331 if (vm_dev->version == 1) { 332 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 333 } else { 334 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 335 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 336 } 337 338 vring_del_virtqueue(vq); 339 340 kfree(info); 341 } 342 343 static void vm_del_vqs(struct virtio_device *vdev) 344 { 345 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 346 struct virtqueue *vq, *n; 347 348 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 349 vm_del_vq(vq); 350 351 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); 352 } 353 354 static void vm_synchronize_cbs(struct virtio_device *vdev) 355 { 356 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 357 358 synchronize_irq(platform_get_irq(vm_dev->pdev, 0)); 359 } 360 361 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index, 362 void (*callback)(struct virtqueue *vq), 363 const char *name, bool ctx) 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; 369 unsigned int num; 370 int err; 371 372 if (!name) 373 return NULL; 374 375 /* Select the queue we're interested in */ 376 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 377 378 /* Queue shouldn't already be set up. */ 379 if (readl(vm_dev->base + (vm_dev->version == 1 ? 380 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) { 381 err = -ENOENT; 382 goto error_available; 383 } 384 385 /* Allocate and fill out our active queue description */ 386 info = kmalloc(sizeof(*info), GFP_KERNEL); 387 if (!info) { 388 err = -ENOMEM; 389 goto error_kmalloc; 390 } 391 392 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); 393 if (num == 0) { 394 err = -ENOENT; 395 goto error_new_virtqueue; 396 } 397 398 /* Create the vring */ 399 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, 400 true, true, ctx, vm_notify, callback, name); 401 if (!vq) { 402 err = -ENOMEM; 403 goto error_new_virtqueue; 404 } 405 406 /* Activate the queue */ 407 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 408 if (vm_dev->version == 1) { 409 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 410 411 /* 412 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 413 * that doesn't fit in 32bit, fail the setup rather than 414 * pretending to be successful. 415 */ 416 if (q_pfn >> 32) { 417 dev_err(&vdev->dev, 418 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 419 0x1ULL << (32 + PAGE_SHIFT - 30)); 420 err = -E2BIG; 421 goto error_bad_pfn; 422 } 423 424 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 425 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 426 } else { 427 u64 addr; 428 429 addr = virtqueue_get_desc_addr(vq); 430 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 431 writel((u32)(addr >> 32), 432 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 433 434 addr = virtqueue_get_avail_addr(vq); 435 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 436 writel((u32)(addr >> 32), 437 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 438 439 addr = virtqueue_get_used_addr(vq); 440 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 441 writel((u32)(addr >> 32), 442 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 443 444 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 445 } 446 447 vq->priv = info; 448 info->vq = vq; 449 450 spin_lock_irqsave(&vm_dev->lock, flags); 451 list_add(&info->node, &vm_dev->virtqueues); 452 spin_unlock_irqrestore(&vm_dev->lock, flags); 453 454 return vq; 455 456 error_bad_pfn: 457 vring_del_virtqueue(vq); 458 error_new_virtqueue: 459 if (vm_dev->version == 1) { 460 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 461 } else { 462 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 463 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 464 } 465 kfree(info); 466 error_kmalloc: 467 error_available: 468 return ERR_PTR(err); 469 } 470 471 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 472 struct virtqueue *vqs[], 473 vq_callback_t *callbacks[], 474 const char * const names[], 475 const bool *ctx, 476 struct irq_affinity *desc) 477 { 478 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 479 int irq = platform_get_irq(vm_dev->pdev, 0); 480 int i, err, queue_idx = 0; 481 482 if (irq < 0) 483 return irq; 484 485 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 486 dev_name(&vdev->dev), vm_dev); 487 if (err) 488 return err; 489 490 for (i = 0; i < nvqs; ++i) { 491 if (!names[i]) { 492 vqs[i] = NULL; 493 continue; 494 } 495 496 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i], 497 ctx ? ctx[i] : false); 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 bool vm_get_shm_region(struct virtio_device *vdev, 515 struct virtio_shm_region *region, u8 id) 516 { 517 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 518 u64 len, addr; 519 520 /* Select the region we're interested in */ 521 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 522 523 /* Read the region size */ 524 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 525 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 526 527 region->len = len; 528 529 /* Check if region length is -1. If that's the case, the shared memory 530 * region does not exist and there is no need to proceed further. 531 */ 532 if (len == ~(u64)0) 533 return false; 534 535 /* Read the region base address */ 536 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 537 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 538 539 region->addr = addr; 540 541 return true; 542 } 543 544 static const struct virtio_config_ops virtio_mmio_config_ops = { 545 .get = vm_get, 546 .set = vm_set, 547 .generation = vm_generation, 548 .get_status = vm_get_status, 549 .set_status = vm_set_status, 550 .reset = vm_reset, 551 .find_vqs = vm_find_vqs, 552 .del_vqs = vm_del_vqs, 553 .get_features = vm_get_features, 554 .finalize_features = vm_finalize_features, 555 .bus_name = vm_bus_name, 556 .get_shm_region = vm_get_shm_region, 557 .synchronize_cbs = vm_synchronize_cbs, 558 }; 559 560 #ifdef CONFIG_PM_SLEEP 561 static int virtio_mmio_freeze(struct device *dev) 562 { 563 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 564 565 return virtio_device_freeze(&vm_dev->vdev); 566 } 567 568 static int virtio_mmio_restore(struct device *dev) 569 { 570 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 571 572 if (vm_dev->version == 1) 573 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 574 575 return virtio_device_restore(&vm_dev->vdev); 576 } 577 578 static const struct dev_pm_ops virtio_mmio_pm_ops = { 579 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) 580 }; 581 #endif 582 583 static void virtio_mmio_release_dev(struct device *_d) 584 { 585 struct virtio_device *vdev = 586 container_of(_d, struct virtio_device, dev); 587 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 588 struct platform_device *pdev = vm_dev->pdev; 589 590 devm_kfree(&pdev->dev, vm_dev); 591 } 592 593 /* Platform device */ 594 595 static int virtio_mmio_probe(struct platform_device *pdev) 596 { 597 struct virtio_mmio_device *vm_dev; 598 unsigned long magic; 599 int rc; 600 601 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL); 602 if (!vm_dev) 603 return -ENOMEM; 604 605 vm_dev->vdev.dev.parent = &pdev->dev; 606 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 607 vm_dev->vdev.config = &virtio_mmio_config_ops; 608 vm_dev->pdev = pdev; 609 INIT_LIST_HEAD(&vm_dev->virtqueues); 610 spin_lock_init(&vm_dev->lock); 611 612 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 613 if (IS_ERR(vm_dev->base)) 614 return PTR_ERR(vm_dev->base); 615 616 /* Check magic value */ 617 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 618 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 619 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 620 return -ENODEV; 621 } 622 623 /* Check device version */ 624 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 625 if (vm_dev->version < 1 || vm_dev->version > 2) { 626 dev_err(&pdev->dev, "Version %ld not supported!\n", 627 vm_dev->version); 628 return -ENXIO; 629 } 630 631 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 632 if (vm_dev->vdev.id.device == 0) { 633 /* 634 * virtio-mmio device with an ID 0 is a (dummy) placeholder 635 * with no function. End probing now with no error reported. 636 */ 637 return -ENODEV; 638 } 639 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 640 641 if (vm_dev->version == 1) { 642 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 643 644 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 645 /* 646 * In the legacy case, ensure our coherently-allocated virtio 647 * ring will be at an address expressable as a 32-bit PFN. 648 */ 649 if (!rc) 650 dma_set_coherent_mask(&pdev->dev, 651 DMA_BIT_MASK(32 + PAGE_SHIFT)); 652 } else { 653 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 654 } 655 if (rc) 656 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 657 if (rc) 658 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 659 660 platform_set_drvdata(pdev, vm_dev); 661 662 rc = register_virtio_device(&vm_dev->vdev); 663 if (rc) 664 put_device(&vm_dev->vdev.dev); 665 666 return rc; 667 } 668 669 static int virtio_mmio_remove(struct platform_device *pdev) 670 { 671 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 672 unregister_virtio_device(&vm_dev->vdev); 673 674 return 0; 675 } 676 677 678 679 /* Devices list parameter */ 680 681 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 682 683 static struct device vm_cmdline_parent = { 684 .init_name = "virtio-mmio-cmdline", 685 }; 686 687 static int vm_cmdline_parent_registered; 688 static int vm_cmdline_id; 689 690 static int vm_cmdline_set(const char *device, 691 const struct kernel_param *kp) 692 { 693 int err; 694 struct resource resources[2] = {}; 695 char *str; 696 long long base, size; 697 unsigned int irq; 698 int processed, consumed = 0; 699 struct platform_device *pdev; 700 701 /* Consume "size" part of the command line parameter */ 702 size = memparse(device, &str); 703 704 /* Get "@<base>:<irq>[:<id>]" chunks */ 705 processed = sscanf(str, "@%lli:%u%n:%d%n", 706 &base, &irq, &consumed, 707 &vm_cmdline_id, &consumed); 708 709 /* 710 * sscanf() must process at least 2 chunks; also there 711 * must be no extra characters after the last chunk, so 712 * str[consumed] must be '\0' 713 */ 714 if (processed < 2 || str[consumed] || irq == 0) 715 return -EINVAL; 716 717 resources[0].flags = IORESOURCE_MEM; 718 resources[0].start = base; 719 resources[0].end = base + size - 1; 720 721 resources[1].flags = IORESOURCE_IRQ; 722 resources[1].start = resources[1].end = irq; 723 724 if (!vm_cmdline_parent_registered) { 725 err = device_register(&vm_cmdline_parent); 726 if (err) { 727 put_device(&vm_cmdline_parent); 728 pr_err("Failed to register parent device!\n"); 729 return err; 730 } 731 vm_cmdline_parent_registered = 1; 732 } 733 734 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", 735 vm_cmdline_id, 736 (unsigned long long)resources[0].start, 737 (unsigned long long)resources[0].end, 738 (int)resources[1].start); 739 740 pdev = platform_device_register_resndata(&vm_cmdline_parent, 741 "virtio-mmio", vm_cmdline_id++, 742 resources, ARRAY_SIZE(resources), NULL, 0); 743 744 return PTR_ERR_OR_ZERO(pdev); 745 } 746 747 static int vm_cmdline_get_device(struct device *dev, void *data) 748 { 749 char *buffer = data; 750 unsigned int len = strlen(buffer); 751 struct platform_device *pdev = to_platform_device(dev); 752 753 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", 754 pdev->resource[0].end - pdev->resource[0].start + 1ULL, 755 (unsigned long long)pdev->resource[0].start, 756 (unsigned long long)pdev->resource[1].start, 757 pdev->id); 758 return 0; 759 } 760 761 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 762 { 763 buffer[0] = '\0'; 764 device_for_each_child(&vm_cmdline_parent, buffer, 765 vm_cmdline_get_device); 766 return strlen(buffer) + 1; 767 } 768 769 static const struct kernel_param_ops vm_cmdline_param_ops = { 770 .set = vm_cmdline_set, 771 .get = vm_cmdline_get, 772 }; 773 774 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 775 776 static int vm_unregister_cmdline_device(struct device *dev, 777 void *data) 778 { 779 platform_device_unregister(to_platform_device(dev)); 780 781 return 0; 782 } 783 784 static void vm_unregister_cmdline_devices(void) 785 { 786 if (vm_cmdline_parent_registered) { 787 device_for_each_child(&vm_cmdline_parent, NULL, 788 vm_unregister_cmdline_device); 789 device_unregister(&vm_cmdline_parent); 790 vm_cmdline_parent_registered = 0; 791 } 792 } 793 794 #else 795 796 static void vm_unregister_cmdline_devices(void) 797 { 798 } 799 800 #endif 801 802 /* Platform driver */ 803 804 static const struct of_device_id virtio_mmio_match[] = { 805 { .compatible = "virtio,mmio", }, 806 {}, 807 }; 808 MODULE_DEVICE_TABLE(of, virtio_mmio_match); 809 810 #ifdef CONFIG_ACPI 811 static const struct acpi_device_id virtio_mmio_acpi_match[] = { 812 { "LNRO0005", }, 813 { } 814 }; 815 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 816 #endif 817 818 static struct platform_driver virtio_mmio_driver = { 819 .probe = virtio_mmio_probe, 820 .remove = virtio_mmio_remove, 821 .driver = { 822 .name = "virtio-mmio", 823 .of_match_table = virtio_mmio_match, 824 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 825 #ifdef CONFIG_PM_SLEEP 826 .pm = &virtio_mmio_pm_ops, 827 #endif 828 }, 829 }; 830 831 static int __init virtio_mmio_init(void) 832 { 833 return platform_driver_register(&virtio_mmio_driver); 834 } 835 836 static void __exit virtio_mmio_exit(void) 837 { 838 platform_driver_unregister(&virtio_mmio_driver); 839 vm_unregister_cmdline_devices(); 840 } 841 842 module_init(virtio_mmio_init); 843 module_exit(virtio_mmio_exit); 844 845 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 846 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 847 MODULE_LICENSE("GPL"); 848