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, u32 size, 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 if (!size || size > num) 399 size = num; 400 401 /* Create the vring */ 402 vq = vring_create_virtqueue(index, size, VIRTIO_MMIO_VRING_ALIGN, vdev, 403 true, true, ctx, vm_notify, callback, name); 404 if (!vq) { 405 err = -ENOMEM; 406 goto error_new_virtqueue; 407 } 408 409 vq->num_max = num; 410 411 /* Activate the queue */ 412 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 413 if (vm_dev->version == 1) { 414 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 415 416 /* 417 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 418 * that doesn't fit in 32bit, fail the setup rather than 419 * pretending to be successful. 420 */ 421 if (q_pfn >> 32) { 422 dev_err(&vdev->dev, 423 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 424 0x1ULL << (32 + PAGE_SHIFT - 30)); 425 err = -E2BIG; 426 goto error_bad_pfn; 427 } 428 429 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 430 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 431 } else { 432 u64 addr; 433 434 addr = virtqueue_get_desc_addr(vq); 435 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 436 writel((u32)(addr >> 32), 437 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 438 439 addr = virtqueue_get_avail_addr(vq); 440 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 441 writel((u32)(addr >> 32), 442 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 443 444 addr = virtqueue_get_used_addr(vq); 445 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 446 writel((u32)(addr >> 32), 447 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 448 449 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 450 } 451 452 vq->priv = info; 453 info->vq = vq; 454 455 spin_lock_irqsave(&vm_dev->lock, flags); 456 list_add(&info->node, &vm_dev->virtqueues); 457 spin_unlock_irqrestore(&vm_dev->lock, flags); 458 459 return vq; 460 461 error_bad_pfn: 462 vring_del_virtqueue(vq); 463 error_new_virtqueue: 464 if (vm_dev->version == 1) { 465 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 466 } else { 467 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 468 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 469 } 470 kfree(info); 471 error_kmalloc: 472 error_available: 473 return ERR_PTR(err); 474 } 475 476 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 477 struct virtqueue *vqs[], 478 vq_callback_t *callbacks[], 479 const char * const names[], 480 u32 sizes[], 481 const bool *ctx, 482 struct irq_affinity *desc) 483 { 484 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 485 int irq = platform_get_irq(vm_dev->pdev, 0); 486 int i, err, queue_idx = 0; 487 488 if (irq < 0) 489 return irq; 490 491 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 492 dev_name(&vdev->dev), vm_dev); 493 if (err) 494 return err; 495 496 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source")) 497 enable_irq_wake(irq); 498 499 for (i = 0; i < nvqs; ++i) { 500 if (!names[i]) { 501 vqs[i] = NULL; 502 continue; 503 } 504 505 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i], 506 sizes ? sizes[i] : 0, 507 ctx ? ctx[i] : false); 508 if (IS_ERR(vqs[i])) { 509 vm_del_vqs(vdev); 510 return PTR_ERR(vqs[i]); 511 } 512 } 513 514 return 0; 515 } 516 517 static const char *vm_bus_name(struct virtio_device *vdev) 518 { 519 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 520 521 return vm_dev->pdev->name; 522 } 523 524 static bool vm_get_shm_region(struct virtio_device *vdev, 525 struct virtio_shm_region *region, u8 id) 526 { 527 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 528 u64 len, addr; 529 530 /* Select the region we're interested in */ 531 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 532 533 /* Read the region size */ 534 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 535 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 536 537 region->len = len; 538 539 /* Check if region length is -1. If that's the case, the shared memory 540 * region does not exist and there is no need to proceed further. 541 */ 542 if (len == ~(u64)0) 543 return false; 544 545 /* Read the region base address */ 546 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 547 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 548 549 region->addr = addr; 550 551 return true; 552 } 553 554 static const struct virtio_config_ops virtio_mmio_config_ops = { 555 .get = vm_get, 556 .set = vm_set, 557 .generation = vm_generation, 558 .get_status = vm_get_status, 559 .set_status = vm_set_status, 560 .reset = vm_reset, 561 .find_vqs = vm_find_vqs, 562 .del_vqs = vm_del_vqs, 563 .get_features = vm_get_features, 564 .finalize_features = vm_finalize_features, 565 .bus_name = vm_bus_name, 566 .get_shm_region = vm_get_shm_region, 567 .synchronize_cbs = vm_synchronize_cbs, 568 }; 569 570 #ifdef CONFIG_PM_SLEEP 571 static int virtio_mmio_freeze(struct device *dev) 572 { 573 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 574 575 return virtio_device_freeze(&vm_dev->vdev); 576 } 577 578 static int virtio_mmio_restore(struct device *dev) 579 { 580 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 581 582 if (vm_dev->version == 1) 583 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 584 585 return virtio_device_restore(&vm_dev->vdev); 586 } 587 588 static const struct dev_pm_ops virtio_mmio_pm_ops = { 589 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) 590 }; 591 #endif 592 593 static void virtio_mmio_release_dev(struct device *_d) 594 { 595 struct virtio_device *vdev = 596 container_of(_d, struct virtio_device, dev); 597 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 598 struct platform_device *pdev = vm_dev->pdev; 599 600 devm_kfree(&pdev->dev, vm_dev); 601 } 602 603 /* Platform device */ 604 605 static int virtio_mmio_probe(struct platform_device *pdev) 606 { 607 struct virtio_mmio_device *vm_dev; 608 unsigned long magic; 609 int rc; 610 611 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL); 612 if (!vm_dev) 613 return -ENOMEM; 614 615 vm_dev->vdev.dev.parent = &pdev->dev; 616 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 617 vm_dev->vdev.config = &virtio_mmio_config_ops; 618 vm_dev->pdev = pdev; 619 INIT_LIST_HEAD(&vm_dev->virtqueues); 620 spin_lock_init(&vm_dev->lock); 621 622 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 623 if (IS_ERR(vm_dev->base)) 624 return PTR_ERR(vm_dev->base); 625 626 /* Check magic value */ 627 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 628 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 629 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 630 return -ENODEV; 631 } 632 633 /* Check device version */ 634 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 635 if (vm_dev->version < 1 || vm_dev->version > 2) { 636 dev_err(&pdev->dev, "Version %ld not supported!\n", 637 vm_dev->version); 638 return -ENXIO; 639 } 640 641 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 642 if (vm_dev->vdev.id.device == 0) { 643 /* 644 * virtio-mmio device with an ID 0 is a (dummy) placeholder 645 * with no function. End probing now with no error reported. 646 */ 647 return -ENODEV; 648 } 649 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 650 651 if (vm_dev->version == 1) { 652 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 653 654 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 655 /* 656 * In the legacy case, ensure our coherently-allocated virtio 657 * ring will be at an address expressable as a 32-bit PFN. 658 */ 659 if (!rc) 660 dma_set_coherent_mask(&pdev->dev, 661 DMA_BIT_MASK(32 + PAGE_SHIFT)); 662 } else { 663 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 664 } 665 if (rc) 666 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 667 if (rc) 668 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 669 670 platform_set_drvdata(pdev, vm_dev); 671 672 rc = register_virtio_device(&vm_dev->vdev); 673 if (rc) 674 put_device(&vm_dev->vdev.dev); 675 676 return rc; 677 } 678 679 static int virtio_mmio_remove(struct platform_device *pdev) 680 { 681 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 682 unregister_virtio_device(&vm_dev->vdev); 683 684 return 0; 685 } 686 687 688 689 /* Devices list parameter */ 690 691 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 692 693 static struct device vm_cmdline_parent = { 694 .init_name = "virtio-mmio-cmdline", 695 }; 696 697 static int vm_cmdline_parent_registered; 698 static int vm_cmdline_id; 699 700 static int vm_cmdline_set(const char *device, 701 const struct kernel_param *kp) 702 { 703 int err; 704 struct resource resources[2] = {}; 705 char *str; 706 long long base, size; 707 unsigned int irq; 708 int processed, consumed = 0; 709 struct platform_device *pdev; 710 711 /* Consume "size" part of the command line parameter */ 712 size = memparse(device, &str); 713 714 /* Get "@<base>:<irq>[:<id>]" chunks */ 715 processed = sscanf(str, "@%lli:%u%n:%d%n", 716 &base, &irq, &consumed, 717 &vm_cmdline_id, &consumed); 718 719 /* 720 * sscanf() must process at least 2 chunks; also there 721 * must be no extra characters after the last chunk, so 722 * str[consumed] must be '\0' 723 */ 724 if (processed < 2 || str[consumed] || irq == 0) 725 return -EINVAL; 726 727 resources[0].flags = IORESOURCE_MEM; 728 resources[0].start = base; 729 resources[0].end = base + size - 1; 730 731 resources[1].flags = IORESOURCE_IRQ; 732 resources[1].start = resources[1].end = irq; 733 734 if (!vm_cmdline_parent_registered) { 735 err = device_register(&vm_cmdline_parent); 736 if (err) { 737 put_device(&vm_cmdline_parent); 738 pr_err("Failed to register parent device!\n"); 739 return err; 740 } 741 vm_cmdline_parent_registered = 1; 742 } 743 744 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", 745 vm_cmdline_id, 746 (unsigned long long)resources[0].start, 747 (unsigned long long)resources[0].end, 748 (int)resources[1].start); 749 750 pdev = platform_device_register_resndata(&vm_cmdline_parent, 751 "virtio-mmio", vm_cmdline_id++, 752 resources, ARRAY_SIZE(resources), NULL, 0); 753 754 return PTR_ERR_OR_ZERO(pdev); 755 } 756 757 static int vm_cmdline_get_device(struct device *dev, void *data) 758 { 759 char *buffer = data; 760 unsigned int len = strlen(buffer); 761 struct platform_device *pdev = to_platform_device(dev); 762 763 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", 764 pdev->resource[0].end - pdev->resource[0].start + 1ULL, 765 (unsigned long long)pdev->resource[0].start, 766 (unsigned long long)pdev->resource[1].start, 767 pdev->id); 768 return 0; 769 } 770 771 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 772 { 773 buffer[0] = '\0'; 774 device_for_each_child(&vm_cmdline_parent, buffer, 775 vm_cmdline_get_device); 776 return strlen(buffer) + 1; 777 } 778 779 static const struct kernel_param_ops vm_cmdline_param_ops = { 780 .set = vm_cmdline_set, 781 .get = vm_cmdline_get, 782 }; 783 784 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 785 786 static int vm_unregister_cmdline_device(struct device *dev, 787 void *data) 788 { 789 platform_device_unregister(to_platform_device(dev)); 790 791 return 0; 792 } 793 794 static void vm_unregister_cmdline_devices(void) 795 { 796 if (vm_cmdline_parent_registered) { 797 device_for_each_child(&vm_cmdline_parent, NULL, 798 vm_unregister_cmdline_device); 799 device_unregister(&vm_cmdline_parent); 800 vm_cmdline_parent_registered = 0; 801 } 802 } 803 804 #else 805 806 static void vm_unregister_cmdline_devices(void) 807 { 808 } 809 810 #endif 811 812 /* Platform driver */ 813 814 static const struct of_device_id virtio_mmio_match[] = { 815 { .compatible = "virtio,mmio", }, 816 {}, 817 }; 818 MODULE_DEVICE_TABLE(of, virtio_mmio_match); 819 820 #ifdef CONFIG_ACPI 821 static const struct acpi_device_id virtio_mmio_acpi_match[] = { 822 { "LNRO0005", }, 823 { } 824 }; 825 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 826 #endif 827 828 static struct platform_driver virtio_mmio_driver = { 829 .probe = virtio_mmio_probe, 830 .remove = virtio_mmio_remove, 831 .driver = { 832 .name = "virtio-mmio", 833 .of_match_table = virtio_mmio_match, 834 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 835 #ifdef CONFIG_PM_SLEEP 836 .pm = &virtio_mmio_pm_ops, 837 #endif 838 }, 839 }; 840 841 static int __init virtio_mmio_init(void) 842 { 843 return platform_driver_register(&virtio_mmio_driver); 844 } 845 846 static void __exit virtio_mmio_exit(void) 847 { 848 platform_driver_unregister(&virtio_mmio_driver); 849 vm_unregister_cmdline_devices(); 850 } 851 852 module_init(virtio_mmio_init); 853 module_exit(virtio_mmio_exit); 854 855 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 856 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 857 MODULE_LICENSE("GPL"); 858