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 static bool vm_notify_with_data(struct virtqueue *vq) 290 { 291 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 292 u32 data = vring_notification_data(vq); 293 294 writel(data, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 295 296 return true; 297 } 298 299 /* Notify all virtqueues on an interrupt. */ 300 static irqreturn_t vm_interrupt(int irq, void *opaque) 301 { 302 struct virtio_mmio_device *vm_dev = opaque; 303 struct virtio_mmio_vq_info *info; 304 unsigned long status; 305 unsigned long flags; 306 irqreturn_t ret = IRQ_NONE; 307 308 /* Read and acknowledge interrupts */ 309 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); 310 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); 311 312 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { 313 virtio_config_changed(&vm_dev->vdev); 314 ret = IRQ_HANDLED; 315 } 316 317 if (likely(status & VIRTIO_MMIO_INT_VRING)) { 318 spin_lock_irqsave(&vm_dev->lock, flags); 319 list_for_each_entry(info, &vm_dev->virtqueues, node) 320 ret |= vring_interrupt(irq, info->vq); 321 spin_unlock_irqrestore(&vm_dev->lock, flags); 322 } 323 324 return ret; 325 } 326 327 328 329 static void vm_del_vq(struct virtqueue *vq) 330 { 331 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 332 struct virtio_mmio_vq_info *info = vq->priv; 333 unsigned long flags; 334 unsigned int index = vq->index; 335 336 spin_lock_irqsave(&vm_dev->lock, flags); 337 list_del(&info->node); 338 spin_unlock_irqrestore(&vm_dev->lock, flags); 339 340 /* Select and deactivate the queue */ 341 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 342 if (vm_dev->version == 1) { 343 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 344 } else { 345 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 346 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 347 } 348 349 vring_del_virtqueue(vq); 350 351 kfree(info); 352 } 353 354 static void vm_del_vqs(struct virtio_device *vdev) 355 { 356 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 357 struct virtqueue *vq, *n; 358 359 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 360 vm_del_vq(vq); 361 362 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); 363 } 364 365 static void vm_synchronize_cbs(struct virtio_device *vdev) 366 { 367 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 368 369 synchronize_irq(platform_get_irq(vm_dev->pdev, 0)); 370 } 371 372 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index, 373 void (*callback)(struct virtqueue *vq), 374 const char *name, bool ctx) 375 { 376 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 377 bool (*notify)(struct virtqueue *vq); 378 struct virtio_mmio_vq_info *info; 379 struct virtqueue *vq; 380 unsigned long flags; 381 unsigned int num; 382 int err; 383 384 if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA)) 385 notify = vm_notify_with_data; 386 else 387 notify = vm_notify; 388 389 if (!name) 390 return NULL; 391 392 /* Select the queue we're interested in */ 393 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 394 395 /* Queue shouldn't already be set up. */ 396 if (readl(vm_dev->base + (vm_dev->version == 1 ? 397 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) { 398 err = -ENOENT; 399 goto error_available; 400 } 401 402 /* Allocate and fill out our active queue description */ 403 info = kmalloc(sizeof(*info), GFP_KERNEL); 404 if (!info) { 405 err = -ENOMEM; 406 goto error_kmalloc; 407 } 408 409 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); 410 if (num == 0) { 411 err = -ENOENT; 412 goto error_new_virtqueue; 413 } 414 415 /* Create the vring */ 416 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, 417 true, true, ctx, notify, callback, name); 418 if (!vq) { 419 err = -ENOMEM; 420 goto error_new_virtqueue; 421 } 422 423 vq->num_max = num; 424 425 /* Activate the queue */ 426 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 427 if (vm_dev->version == 1) { 428 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 429 430 /* 431 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 432 * that doesn't fit in 32bit, fail the setup rather than 433 * pretending to be successful. 434 */ 435 if (q_pfn >> 32) { 436 dev_err(&vdev->dev, 437 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 438 0x1ULL << (32 + PAGE_SHIFT - 30)); 439 err = -E2BIG; 440 goto error_bad_pfn; 441 } 442 443 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 444 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 445 } else { 446 u64 addr; 447 448 addr = virtqueue_get_desc_addr(vq); 449 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 450 writel((u32)(addr >> 32), 451 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 452 453 addr = virtqueue_get_avail_addr(vq); 454 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 455 writel((u32)(addr >> 32), 456 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 457 458 addr = virtqueue_get_used_addr(vq); 459 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 460 writel((u32)(addr >> 32), 461 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 462 463 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 464 } 465 466 vq->priv = info; 467 info->vq = vq; 468 469 spin_lock_irqsave(&vm_dev->lock, flags); 470 list_add(&info->node, &vm_dev->virtqueues); 471 spin_unlock_irqrestore(&vm_dev->lock, flags); 472 473 return vq; 474 475 error_bad_pfn: 476 vring_del_virtqueue(vq); 477 error_new_virtqueue: 478 if (vm_dev->version == 1) { 479 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 480 } else { 481 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 482 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 483 } 484 kfree(info); 485 error_kmalloc: 486 error_available: 487 return ERR_PTR(err); 488 } 489 490 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 491 struct virtqueue *vqs[], 492 vq_callback_t *callbacks[], 493 const char * const names[], 494 const bool *ctx, 495 struct irq_affinity *desc) 496 { 497 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 498 int irq = platform_get_irq(vm_dev->pdev, 0); 499 int i, err, queue_idx = 0; 500 501 if (irq < 0) 502 return irq; 503 504 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 505 dev_name(&vdev->dev), vm_dev); 506 if (err) 507 return err; 508 509 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source")) 510 enable_irq_wake(irq); 511 512 for (i = 0; i < nvqs; ++i) { 513 if (!names[i]) { 514 vqs[i] = NULL; 515 continue; 516 } 517 518 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i], 519 ctx ? ctx[i] : false); 520 if (IS_ERR(vqs[i])) { 521 vm_del_vqs(vdev); 522 return PTR_ERR(vqs[i]); 523 } 524 } 525 526 return 0; 527 } 528 529 static const char *vm_bus_name(struct virtio_device *vdev) 530 { 531 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 532 533 return vm_dev->pdev->name; 534 } 535 536 static bool vm_get_shm_region(struct virtio_device *vdev, 537 struct virtio_shm_region *region, u8 id) 538 { 539 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 540 u64 len, addr; 541 542 /* Select the region we're interested in */ 543 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 544 545 /* Read the region size */ 546 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 547 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 548 549 region->len = len; 550 551 /* Check if region length is -1. If that's the case, the shared memory 552 * region does not exist and there is no need to proceed further. 553 */ 554 if (len == ~(u64)0) 555 return false; 556 557 /* Read the region base address */ 558 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 559 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 560 561 region->addr = addr; 562 563 return true; 564 } 565 566 static const struct virtio_config_ops virtio_mmio_config_ops = { 567 .get = vm_get, 568 .set = vm_set, 569 .generation = vm_generation, 570 .get_status = vm_get_status, 571 .set_status = vm_set_status, 572 .reset = vm_reset, 573 .find_vqs = vm_find_vqs, 574 .del_vqs = vm_del_vqs, 575 .get_features = vm_get_features, 576 .finalize_features = vm_finalize_features, 577 .bus_name = vm_bus_name, 578 .get_shm_region = vm_get_shm_region, 579 .synchronize_cbs = vm_synchronize_cbs, 580 }; 581 582 #ifdef CONFIG_PM_SLEEP 583 static int virtio_mmio_freeze(struct device *dev) 584 { 585 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 586 587 return virtio_device_freeze(&vm_dev->vdev); 588 } 589 590 static int virtio_mmio_restore(struct device *dev) 591 { 592 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 593 594 if (vm_dev->version == 1) 595 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 596 597 return virtio_device_restore(&vm_dev->vdev); 598 } 599 600 static const struct dev_pm_ops virtio_mmio_pm_ops = { 601 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) 602 }; 603 #endif 604 605 static void virtio_mmio_release_dev(struct device *_d) 606 { 607 struct virtio_device *vdev = 608 container_of(_d, struct virtio_device, dev); 609 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 610 struct platform_device *pdev = vm_dev->pdev; 611 612 devm_kfree(&pdev->dev, vm_dev); 613 } 614 615 /* Platform device */ 616 617 static int virtio_mmio_probe(struct platform_device *pdev) 618 { 619 struct virtio_mmio_device *vm_dev; 620 unsigned long magic; 621 int rc; 622 623 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL); 624 if (!vm_dev) 625 return -ENOMEM; 626 627 vm_dev->vdev.dev.parent = &pdev->dev; 628 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 629 vm_dev->vdev.config = &virtio_mmio_config_ops; 630 vm_dev->pdev = pdev; 631 INIT_LIST_HEAD(&vm_dev->virtqueues); 632 spin_lock_init(&vm_dev->lock); 633 634 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 635 if (IS_ERR(vm_dev->base)) 636 return PTR_ERR(vm_dev->base); 637 638 /* Check magic value */ 639 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 640 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 641 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 642 return -ENODEV; 643 } 644 645 /* Check device version */ 646 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 647 if (vm_dev->version < 1 || vm_dev->version > 2) { 648 dev_err(&pdev->dev, "Version %ld not supported!\n", 649 vm_dev->version); 650 return -ENXIO; 651 } 652 653 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 654 if (vm_dev->vdev.id.device == 0) { 655 /* 656 * virtio-mmio device with an ID 0 is a (dummy) placeholder 657 * with no function. End probing now with no error reported. 658 */ 659 return -ENODEV; 660 } 661 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 662 663 if (vm_dev->version == 1) { 664 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 665 666 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 667 /* 668 * In the legacy case, ensure our coherently-allocated virtio 669 * ring will be at an address expressable as a 32-bit PFN. 670 */ 671 if (!rc) 672 dma_set_coherent_mask(&pdev->dev, 673 DMA_BIT_MASK(32 + PAGE_SHIFT)); 674 } else { 675 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 676 } 677 if (rc) 678 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 679 if (rc) 680 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 681 682 platform_set_drvdata(pdev, vm_dev); 683 684 rc = register_virtio_device(&vm_dev->vdev); 685 if (rc) 686 put_device(&vm_dev->vdev.dev); 687 688 return rc; 689 } 690 691 static int virtio_mmio_remove(struct platform_device *pdev) 692 { 693 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 694 unregister_virtio_device(&vm_dev->vdev); 695 696 return 0; 697 } 698 699 700 701 /* Devices list parameter */ 702 703 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 704 705 static struct device vm_cmdline_parent = { 706 .init_name = "virtio-mmio-cmdline", 707 }; 708 709 static int vm_cmdline_parent_registered; 710 static int vm_cmdline_id; 711 712 static int vm_cmdline_set(const char *device, 713 const struct kernel_param *kp) 714 { 715 int err; 716 struct resource resources[2] = {}; 717 char *str; 718 long long base, size; 719 unsigned int irq; 720 int processed, consumed = 0; 721 struct platform_device *pdev; 722 723 /* Consume "size" part of the command line parameter */ 724 size = memparse(device, &str); 725 726 /* Get "@<base>:<irq>[:<id>]" chunks */ 727 processed = sscanf(str, "@%lli:%u%n:%d%n", 728 &base, &irq, &consumed, 729 &vm_cmdline_id, &consumed); 730 731 /* 732 * sscanf() must process at least 2 chunks; also there 733 * must be no extra characters after the last chunk, so 734 * str[consumed] must be '\0' 735 */ 736 if (processed < 2 || str[consumed] || irq == 0) 737 return -EINVAL; 738 739 resources[0].flags = IORESOURCE_MEM; 740 resources[0].start = base; 741 resources[0].end = base + size - 1; 742 743 resources[1].flags = IORESOURCE_IRQ; 744 resources[1].start = resources[1].end = irq; 745 746 if (!vm_cmdline_parent_registered) { 747 err = device_register(&vm_cmdline_parent); 748 if (err) { 749 put_device(&vm_cmdline_parent); 750 pr_err("Failed to register parent device!\n"); 751 return err; 752 } 753 vm_cmdline_parent_registered = 1; 754 } 755 756 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", 757 vm_cmdline_id, 758 (unsigned long long)resources[0].start, 759 (unsigned long long)resources[0].end, 760 (int)resources[1].start); 761 762 pdev = platform_device_register_resndata(&vm_cmdline_parent, 763 "virtio-mmio", vm_cmdline_id++, 764 resources, ARRAY_SIZE(resources), NULL, 0); 765 766 return PTR_ERR_OR_ZERO(pdev); 767 } 768 769 static int vm_cmdline_get_device(struct device *dev, void *data) 770 { 771 char *buffer = data; 772 unsigned int len = strlen(buffer); 773 struct platform_device *pdev = to_platform_device(dev); 774 775 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", 776 pdev->resource[0].end - pdev->resource[0].start + 1ULL, 777 (unsigned long long)pdev->resource[0].start, 778 (unsigned long long)pdev->resource[1].start, 779 pdev->id); 780 return 0; 781 } 782 783 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 784 { 785 buffer[0] = '\0'; 786 device_for_each_child(&vm_cmdline_parent, buffer, 787 vm_cmdline_get_device); 788 return strlen(buffer) + 1; 789 } 790 791 static const struct kernel_param_ops vm_cmdline_param_ops = { 792 .set = vm_cmdline_set, 793 .get = vm_cmdline_get, 794 }; 795 796 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 797 798 static int vm_unregister_cmdline_device(struct device *dev, 799 void *data) 800 { 801 platform_device_unregister(to_platform_device(dev)); 802 803 return 0; 804 } 805 806 static void vm_unregister_cmdline_devices(void) 807 { 808 if (vm_cmdline_parent_registered) { 809 device_for_each_child(&vm_cmdline_parent, NULL, 810 vm_unregister_cmdline_device); 811 device_unregister(&vm_cmdline_parent); 812 vm_cmdline_parent_registered = 0; 813 } 814 } 815 816 #else 817 818 static void vm_unregister_cmdline_devices(void) 819 { 820 } 821 822 #endif 823 824 /* Platform driver */ 825 826 static const struct of_device_id virtio_mmio_match[] = { 827 { .compatible = "virtio,mmio", }, 828 {}, 829 }; 830 MODULE_DEVICE_TABLE(of, virtio_mmio_match); 831 832 #ifdef CONFIG_ACPI 833 static const struct acpi_device_id virtio_mmio_acpi_match[] = { 834 { "LNRO0005", }, 835 { } 836 }; 837 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 838 #endif 839 840 static struct platform_driver virtio_mmio_driver = { 841 .probe = virtio_mmio_probe, 842 .remove = virtio_mmio_remove, 843 .driver = { 844 .name = "virtio-mmio", 845 .of_match_table = virtio_mmio_match, 846 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 847 #ifdef CONFIG_PM_SLEEP 848 .pm = &virtio_mmio_pm_ops, 849 #endif 850 }, 851 }; 852 853 static int __init virtio_mmio_init(void) 854 { 855 return platform_driver_register(&virtio_mmio_driver); 856 } 857 858 static void __exit virtio_mmio_exit(void) 859 { 860 platform_driver_unregister(&virtio_mmio_driver); 861 vm_unregister_cmdline_devices(); 862 } 863 864 module_init(virtio_mmio_init); 865 module_exit(virtio_mmio_exit); 866 867 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 868 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 869 MODULE_LICENSE("GPL"); 870