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/of.h> 65 #include <linux/platform_device.h> 66 #include <linux/pm.h> 67 #include <linux/slab.h> 68 #include <linux/spinlock.h> 69 #include <linux/virtio.h> 70 #include <linux/virtio_config.h> 71 #include <uapi/linux/virtio_mmio.h> 72 #include <linux/virtio_ring.h> 73 74 75 76 /* The alignment to use between consumer and producer parts of vring. 77 * Currently hardcoded to the page size. */ 78 #define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE 79 80 81 82 #define to_virtio_mmio_device(_plat_dev) \ 83 container_of(_plat_dev, struct virtio_mmio_device, vdev) 84 85 struct virtio_mmio_device { 86 struct virtio_device vdev; 87 struct platform_device *pdev; 88 89 void __iomem *base; 90 unsigned long version; 91 92 /* a list of queues so we can dispatch IRQs */ 93 spinlock_t lock; 94 struct list_head virtqueues; 95 }; 96 97 struct virtio_mmio_vq_info { 98 /* the actual virtqueue */ 99 struct virtqueue *vq; 100 101 /* the list node for the virtqueues list */ 102 struct list_head node; 103 }; 104 105 106 107 /* Configuration interface */ 108 109 static u64 vm_get_features(struct virtio_device *vdev) 110 { 111 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 112 u64 features; 113 114 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 115 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 116 features <<= 32; 117 118 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 119 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 120 121 return features; 122 } 123 124 static int vm_finalize_features(struct virtio_device *vdev) 125 { 126 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 127 128 /* Give virtio_ring a chance to accept features. */ 129 vring_transport_features(vdev); 130 131 /* Make sure there are no mixed devices */ 132 if (vm_dev->version == 2 && 133 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) { 134 dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n"); 135 return -EINVAL; 136 } 137 138 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 139 writel((u32)(vdev->features >> 32), 140 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 141 142 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 143 writel((u32)vdev->features, 144 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 145 146 return 0; 147 } 148 149 static void vm_get(struct virtio_device *vdev, unsigned int offset, 150 void *buf, unsigned int len) 151 { 152 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 153 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 154 u8 b; 155 __le16 w; 156 __le32 l; 157 158 if (vm_dev->version == 1) { 159 u8 *ptr = buf; 160 int i; 161 162 for (i = 0; i < len; i++) 163 ptr[i] = readb(base + offset + i); 164 return; 165 } 166 167 switch (len) { 168 case 1: 169 b = readb(base + offset); 170 memcpy(buf, &b, sizeof b); 171 break; 172 case 2: 173 w = cpu_to_le16(readw(base + offset)); 174 memcpy(buf, &w, sizeof w); 175 break; 176 case 4: 177 l = cpu_to_le32(readl(base + offset)); 178 memcpy(buf, &l, sizeof l); 179 break; 180 case 8: 181 l = cpu_to_le32(readl(base + offset)); 182 memcpy(buf, &l, sizeof l); 183 l = cpu_to_le32(ioread32(base + offset + sizeof l)); 184 memcpy(buf + sizeof l, &l, sizeof l); 185 break; 186 default: 187 BUG(); 188 } 189 } 190 191 static void vm_set(struct virtio_device *vdev, unsigned int offset, 192 const void *buf, unsigned int len) 193 { 194 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 195 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 196 u8 b; 197 __le16 w; 198 __le32 l; 199 200 if (vm_dev->version == 1) { 201 const u8 *ptr = buf; 202 int i; 203 204 for (i = 0; i < len; i++) 205 writeb(ptr[i], base + offset + i); 206 207 return; 208 } 209 210 switch (len) { 211 case 1: 212 memcpy(&b, buf, sizeof b); 213 writeb(b, base + offset); 214 break; 215 case 2: 216 memcpy(&w, buf, sizeof w); 217 writew(le16_to_cpu(w), base + offset); 218 break; 219 case 4: 220 memcpy(&l, buf, sizeof l); 221 writel(le32_to_cpu(l), base + offset); 222 break; 223 case 8: 224 memcpy(&l, buf, sizeof l); 225 writel(le32_to_cpu(l), base + offset); 226 memcpy(&l, buf + sizeof l, sizeof l); 227 writel(le32_to_cpu(l), base + offset + sizeof l); 228 break; 229 default: 230 BUG(); 231 } 232 } 233 234 static u32 vm_generation(struct virtio_device *vdev) 235 { 236 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 237 238 if (vm_dev->version == 1) 239 return 0; 240 else 241 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION); 242 } 243 244 static u8 vm_get_status(struct virtio_device *vdev) 245 { 246 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 247 248 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff; 249 } 250 251 static void vm_set_status(struct virtio_device *vdev, u8 status) 252 { 253 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 254 255 /* We should never be setting status to 0. */ 256 BUG_ON(status == 0); 257 258 /* 259 * Per memory-barriers.txt, wmb() is not needed to guarantee 260 * that the cache coherent memory writes have completed 261 * before writing to the MMIO region. 262 */ 263 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS); 264 } 265 266 static void vm_reset(struct virtio_device *vdev) 267 { 268 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 269 270 /* 0 status means a reset. */ 271 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS); 272 } 273 274 275 276 /* Transport interface */ 277 278 /* the notify function used when creating a virt queue */ 279 static bool vm_notify(struct virtqueue *vq) 280 { 281 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 282 283 /* We write the queue's selector into the notification register to 284 * signal the other end */ 285 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 286 return true; 287 } 288 289 /* Notify all virtqueues on an interrupt. */ 290 static irqreturn_t vm_interrupt(int irq, void *opaque) 291 { 292 struct virtio_mmio_device *vm_dev = opaque; 293 struct virtio_mmio_vq_info *info; 294 unsigned long status; 295 unsigned long flags; 296 irqreturn_t ret = IRQ_NONE; 297 298 /* Read and acknowledge interrupts */ 299 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); 300 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); 301 302 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { 303 virtio_config_changed(&vm_dev->vdev); 304 ret = IRQ_HANDLED; 305 } 306 307 if (likely(status & VIRTIO_MMIO_INT_VRING)) { 308 spin_lock_irqsave(&vm_dev->lock, flags); 309 list_for_each_entry(info, &vm_dev->virtqueues, node) 310 ret |= vring_interrupt(irq, info->vq); 311 spin_unlock_irqrestore(&vm_dev->lock, flags); 312 } 313 314 return ret; 315 } 316 317 318 319 static void vm_del_vq(struct virtqueue *vq) 320 { 321 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 322 struct virtio_mmio_vq_info *info = vq->priv; 323 unsigned long flags; 324 unsigned int index = vq->index; 325 326 spin_lock_irqsave(&vm_dev->lock, flags); 327 list_del(&info->node); 328 spin_unlock_irqrestore(&vm_dev->lock, flags); 329 330 /* Select and deactivate the queue */ 331 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 332 if (vm_dev->version == 1) { 333 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 334 } else { 335 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 336 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 337 } 338 339 vring_del_virtqueue(vq); 340 341 kfree(info); 342 } 343 344 static void vm_del_vqs(struct virtio_device *vdev) 345 { 346 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 347 struct virtqueue *vq, *n; 348 349 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 350 vm_del_vq(vq); 351 352 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); 353 } 354 355 static void vm_synchronize_cbs(struct virtio_device *vdev) 356 { 357 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 358 359 synchronize_irq(platform_get_irq(vm_dev->pdev, 0)); 360 } 361 362 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index, 363 void (*callback)(struct virtqueue *vq), 364 const char *name, bool ctx) 365 { 366 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 367 struct virtio_mmio_vq_info *info; 368 struct virtqueue *vq; 369 unsigned long flags; 370 unsigned int num; 371 int err; 372 373 if (!name) 374 return NULL; 375 376 /* Select the queue we're interested in */ 377 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 378 379 /* Queue shouldn't already be set up. */ 380 if (readl(vm_dev->base + (vm_dev->version == 1 ? 381 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) { 382 err = -ENOENT; 383 goto error_available; 384 } 385 386 /* Allocate and fill out our active queue description */ 387 info = kmalloc(sizeof(*info), GFP_KERNEL); 388 if (!info) { 389 err = -ENOMEM; 390 goto error_kmalloc; 391 } 392 393 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); 394 if (num == 0) { 395 err = -ENOENT; 396 goto error_new_virtqueue; 397 } 398 399 /* Create the vring */ 400 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, 401 true, true, ctx, vm_notify, callback, name); 402 if (!vq) { 403 err = -ENOMEM; 404 goto error_new_virtqueue; 405 } 406 407 vq->num_max = num; 408 409 /* Activate the queue */ 410 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 411 if (vm_dev->version == 1) { 412 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 413 414 /* 415 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 416 * that doesn't fit in 32bit, fail the setup rather than 417 * pretending to be successful. 418 */ 419 if (q_pfn >> 32) { 420 dev_err(&vdev->dev, 421 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 422 0x1ULL << (32 + PAGE_SHIFT - 30)); 423 err = -E2BIG; 424 goto error_bad_pfn; 425 } 426 427 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 428 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 429 } else { 430 u64 addr; 431 432 addr = virtqueue_get_desc_addr(vq); 433 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 434 writel((u32)(addr >> 32), 435 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 436 437 addr = virtqueue_get_avail_addr(vq); 438 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 439 writel((u32)(addr >> 32), 440 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 441 442 addr = virtqueue_get_used_addr(vq); 443 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 444 writel((u32)(addr >> 32), 445 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 446 447 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 448 } 449 450 vq->priv = info; 451 info->vq = vq; 452 453 spin_lock_irqsave(&vm_dev->lock, flags); 454 list_add(&info->node, &vm_dev->virtqueues); 455 spin_unlock_irqrestore(&vm_dev->lock, flags); 456 457 return vq; 458 459 error_bad_pfn: 460 vring_del_virtqueue(vq); 461 error_new_virtqueue: 462 if (vm_dev->version == 1) { 463 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 464 } else { 465 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 466 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 467 } 468 kfree(info); 469 error_kmalloc: 470 error_available: 471 return ERR_PTR(err); 472 } 473 474 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 475 struct virtqueue *vqs[], 476 vq_callback_t *callbacks[], 477 const char * const names[], 478 const bool *ctx, 479 struct irq_affinity *desc) 480 { 481 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 482 int irq = platform_get_irq(vm_dev->pdev, 0); 483 int i, err, queue_idx = 0; 484 485 if (irq < 0) 486 return irq; 487 488 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 489 dev_name(&vdev->dev), vm_dev); 490 if (err) 491 return err; 492 493 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source")) 494 enable_irq_wake(irq); 495 496 for (i = 0; i < nvqs; ++i) { 497 if (!names[i]) { 498 vqs[i] = NULL; 499 continue; 500 } 501 502 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i], 503 ctx ? ctx[i] : false); 504 if (IS_ERR(vqs[i])) { 505 vm_del_vqs(vdev); 506 return PTR_ERR(vqs[i]); 507 } 508 } 509 510 return 0; 511 } 512 513 static const char *vm_bus_name(struct virtio_device *vdev) 514 { 515 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 516 517 return vm_dev->pdev->name; 518 } 519 520 static bool vm_get_shm_region(struct virtio_device *vdev, 521 struct virtio_shm_region *region, u8 id) 522 { 523 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 524 u64 len, addr; 525 526 /* Select the region we're interested in */ 527 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 528 529 /* Read the region size */ 530 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 531 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 532 533 region->len = len; 534 535 /* Check if region length is -1. If that's the case, the shared memory 536 * region does not exist and there is no need to proceed further. 537 */ 538 if (len == ~(u64)0) 539 return false; 540 541 /* Read the region base address */ 542 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 543 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 544 545 region->addr = addr; 546 547 return true; 548 } 549 550 static const struct virtio_config_ops virtio_mmio_config_ops = { 551 .get = vm_get, 552 .set = vm_set, 553 .generation = vm_generation, 554 .get_status = vm_get_status, 555 .set_status = vm_set_status, 556 .reset = vm_reset, 557 .find_vqs = vm_find_vqs, 558 .del_vqs = vm_del_vqs, 559 .get_features = vm_get_features, 560 .finalize_features = vm_finalize_features, 561 .bus_name = vm_bus_name, 562 .get_shm_region = vm_get_shm_region, 563 .synchronize_cbs = vm_synchronize_cbs, 564 }; 565 566 #ifdef CONFIG_PM_SLEEP 567 static int virtio_mmio_freeze(struct device *dev) 568 { 569 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 570 571 return virtio_device_freeze(&vm_dev->vdev); 572 } 573 574 static int virtio_mmio_restore(struct device *dev) 575 { 576 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 577 578 if (vm_dev->version == 1) 579 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 580 581 return virtio_device_restore(&vm_dev->vdev); 582 } 583 584 static const struct dev_pm_ops virtio_mmio_pm_ops = { 585 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) 586 }; 587 #endif 588 589 static void virtio_mmio_release_dev(struct device *_d) 590 { 591 struct virtio_device *vdev = 592 container_of(_d, struct virtio_device, dev); 593 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 594 struct platform_device *pdev = vm_dev->pdev; 595 596 devm_kfree(&pdev->dev, vm_dev); 597 } 598 599 /* Platform device */ 600 601 static int virtio_mmio_probe(struct platform_device *pdev) 602 { 603 struct virtio_mmio_device *vm_dev; 604 unsigned long magic; 605 int rc; 606 607 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL); 608 if (!vm_dev) 609 return -ENOMEM; 610 611 vm_dev->vdev.dev.parent = &pdev->dev; 612 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 613 vm_dev->vdev.config = &virtio_mmio_config_ops; 614 vm_dev->pdev = pdev; 615 INIT_LIST_HEAD(&vm_dev->virtqueues); 616 spin_lock_init(&vm_dev->lock); 617 618 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 619 if (IS_ERR(vm_dev->base)) 620 return PTR_ERR(vm_dev->base); 621 622 /* Check magic value */ 623 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 624 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 625 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 626 return -ENODEV; 627 } 628 629 /* Check device version */ 630 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 631 if (vm_dev->version < 1 || vm_dev->version > 2) { 632 dev_err(&pdev->dev, "Version %ld not supported!\n", 633 vm_dev->version); 634 return -ENXIO; 635 } 636 637 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 638 if (vm_dev->vdev.id.device == 0) { 639 /* 640 * virtio-mmio device with an ID 0 is a (dummy) placeholder 641 * with no function. End probing now with no error reported. 642 */ 643 return -ENODEV; 644 } 645 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 646 647 if (vm_dev->version == 1) { 648 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 649 650 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 651 /* 652 * In the legacy case, ensure our coherently-allocated virtio 653 * ring will be at an address expressable as a 32-bit PFN. 654 */ 655 if (!rc) 656 dma_set_coherent_mask(&pdev->dev, 657 DMA_BIT_MASK(32 + PAGE_SHIFT)); 658 } else { 659 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 660 } 661 if (rc) 662 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 663 if (rc) 664 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 665 666 platform_set_drvdata(pdev, vm_dev); 667 668 rc = register_virtio_device(&vm_dev->vdev); 669 if (rc) 670 put_device(&vm_dev->vdev.dev); 671 672 return rc; 673 } 674 675 static int virtio_mmio_remove(struct platform_device *pdev) 676 { 677 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 678 unregister_virtio_device(&vm_dev->vdev); 679 680 return 0; 681 } 682 683 684 685 /* Devices list parameter */ 686 687 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 688 689 static struct device vm_cmdline_parent = { 690 .init_name = "virtio-mmio-cmdline", 691 }; 692 693 static int vm_cmdline_parent_registered; 694 static int vm_cmdline_id; 695 696 static int vm_cmdline_set(const char *device, 697 const struct kernel_param *kp) 698 { 699 int err; 700 struct resource resources[2] = {}; 701 char *str; 702 long long base, size; 703 unsigned int irq; 704 int processed, consumed = 0; 705 struct platform_device *pdev; 706 707 /* Consume "size" part of the command line parameter */ 708 size = memparse(device, &str); 709 710 /* Get "@<base>:<irq>[:<id>]" chunks */ 711 processed = sscanf(str, "@%lli:%u%n:%d%n", 712 &base, &irq, &consumed, 713 &vm_cmdline_id, &consumed); 714 715 /* 716 * sscanf() must process at least 2 chunks; also there 717 * must be no extra characters after the last chunk, so 718 * str[consumed] must be '\0' 719 */ 720 if (processed < 2 || str[consumed] || irq == 0) 721 return -EINVAL; 722 723 resources[0].flags = IORESOURCE_MEM; 724 resources[0].start = base; 725 resources[0].end = base + size - 1; 726 727 resources[1].flags = IORESOURCE_IRQ; 728 resources[1].start = resources[1].end = irq; 729 730 if (!vm_cmdline_parent_registered) { 731 err = device_register(&vm_cmdline_parent); 732 if (err) { 733 put_device(&vm_cmdline_parent); 734 pr_err("Failed to register parent device!\n"); 735 return err; 736 } 737 vm_cmdline_parent_registered = 1; 738 } 739 740 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", 741 vm_cmdline_id, 742 (unsigned long long)resources[0].start, 743 (unsigned long long)resources[0].end, 744 (int)resources[1].start); 745 746 pdev = platform_device_register_resndata(&vm_cmdline_parent, 747 "virtio-mmio", vm_cmdline_id++, 748 resources, ARRAY_SIZE(resources), NULL, 0); 749 750 return PTR_ERR_OR_ZERO(pdev); 751 } 752 753 static int vm_cmdline_get_device(struct device *dev, void *data) 754 { 755 char *buffer = data; 756 unsigned int len = strlen(buffer); 757 struct platform_device *pdev = to_platform_device(dev); 758 759 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", 760 pdev->resource[0].end - pdev->resource[0].start + 1ULL, 761 (unsigned long long)pdev->resource[0].start, 762 (unsigned long long)pdev->resource[1].start, 763 pdev->id); 764 return 0; 765 } 766 767 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 768 { 769 buffer[0] = '\0'; 770 device_for_each_child(&vm_cmdline_parent, buffer, 771 vm_cmdline_get_device); 772 return strlen(buffer) + 1; 773 } 774 775 static const struct kernel_param_ops vm_cmdline_param_ops = { 776 .set = vm_cmdline_set, 777 .get = vm_cmdline_get, 778 }; 779 780 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 781 782 static int vm_unregister_cmdline_device(struct device *dev, 783 void *data) 784 { 785 platform_device_unregister(to_platform_device(dev)); 786 787 return 0; 788 } 789 790 static void vm_unregister_cmdline_devices(void) 791 { 792 if (vm_cmdline_parent_registered) { 793 device_for_each_child(&vm_cmdline_parent, NULL, 794 vm_unregister_cmdline_device); 795 device_unregister(&vm_cmdline_parent); 796 vm_cmdline_parent_registered = 0; 797 } 798 } 799 800 #else 801 802 static void vm_unregister_cmdline_devices(void) 803 { 804 } 805 806 #endif 807 808 /* Platform driver */ 809 810 static const struct of_device_id virtio_mmio_match[] = { 811 { .compatible = "virtio,mmio", }, 812 {}, 813 }; 814 MODULE_DEVICE_TABLE(of, virtio_mmio_match); 815 816 #ifdef CONFIG_ACPI 817 static const struct acpi_device_id virtio_mmio_acpi_match[] = { 818 { "LNRO0005", }, 819 { } 820 }; 821 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 822 #endif 823 824 static struct platform_driver virtio_mmio_driver = { 825 .probe = virtio_mmio_probe, 826 .remove = virtio_mmio_remove, 827 .driver = { 828 .name = "virtio-mmio", 829 .of_match_table = virtio_mmio_match, 830 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 831 #ifdef CONFIG_PM_SLEEP 832 .pm = &virtio_mmio_pm_ops, 833 #endif 834 }, 835 }; 836 837 static int __init virtio_mmio_init(void) 838 { 839 return platform_driver_register(&virtio_mmio_driver); 840 } 841 842 static void __exit virtio_mmio_exit(void) 843 { 844 platform_driver_unregister(&virtio_mmio_driver); 845 vm_unregister_cmdline_devices(); 846 } 847 848 module_init(virtio_mmio_init); 849 module_exit(virtio_mmio_exit); 850 851 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 852 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 853 MODULE_LICENSE("GPL"); 854