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 static bool vm_notify_with_data(struct virtqueue *vq) 289 { 290 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 291 u32 data = vring_notification_data(vq); 292 293 writel(data, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 294 295 return true; 296 } 297 298 /* Notify all virtqueues on an interrupt. */ 299 static irqreturn_t vm_interrupt(int irq, void *opaque) 300 { 301 struct virtio_mmio_device *vm_dev = opaque; 302 struct virtio_mmio_vq_info *info; 303 unsigned long status; 304 unsigned long flags; 305 irqreturn_t ret = IRQ_NONE; 306 307 /* Read and acknowledge interrupts */ 308 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); 309 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); 310 311 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { 312 virtio_config_changed(&vm_dev->vdev); 313 ret = IRQ_HANDLED; 314 } 315 316 if (likely(status & VIRTIO_MMIO_INT_VRING)) { 317 spin_lock_irqsave(&vm_dev->lock, flags); 318 list_for_each_entry(info, &vm_dev->virtqueues, node) 319 ret |= vring_interrupt(irq, info->vq); 320 spin_unlock_irqrestore(&vm_dev->lock, flags); 321 } 322 323 return ret; 324 } 325 326 327 328 static void vm_del_vq(struct virtqueue *vq) 329 { 330 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 331 struct virtio_mmio_vq_info *info = vq->priv; 332 unsigned long flags; 333 unsigned int index = vq->index; 334 335 spin_lock_irqsave(&vm_dev->lock, flags); 336 list_del(&info->node); 337 spin_unlock_irqrestore(&vm_dev->lock, flags); 338 339 /* Select and deactivate the queue */ 340 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 341 if (vm_dev->version == 1) { 342 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 343 } else { 344 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 345 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 346 } 347 348 vring_del_virtqueue(vq); 349 350 kfree(info); 351 } 352 353 static void vm_del_vqs(struct virtio_device *vdev) 354 { 355 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 356 struct virtqueue *vq, *n; 357 358 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 359 vm_del_vq(vq); 360 361 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); 362 } 363 364 static void vm_synchronize_cbs(struct virtio_device *vdev) 365 { 366 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 367 368 synchronize_irq(platform_get_irq(vm_dev->pdev, 0)); 369 } 370 371 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index, 372 void (*callback)(struct virtqueue *vq), 373 const char *name, bool ctx) 374 { 375 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 376 bool (*notify)(struct virtqueue *vq); 377 struct virtio_mmio_vq_info *info; 378 struct virtqueue *vq; 379 unsigned long flags; 380 unsigned int num; 381 int err; 382 383 if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA)) 384 notify = vm_notify_with_data; 385 else 386 notify = vm_notify; 387 388 if (!name) 389 return NULL; 390 391 /* Select the queue we're interested in */ 392 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 393 394 /* Queue shouldn't already be set up. */ 395 if (readl(vm_dev->base + (vm_dev->version == 1 ? 396 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) { 397 err = -ENOENT; 398 goto error_available; 399 } 400 401 /* Allocate and fill out our active queue description */ 402 info = kmalloc(sizeof(*info), GFP_KERNEL); 403 if (!info) { 404 err = -ENOMEM; 405 goto error_kmalloc; 406 } 407 408 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); 409 if (num == 0) { 410 err = -ENOENT; 411 goto error_new_virtqueue; 412 } 413 414 /* Create the vring */ 415 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, 416 true, true, ctx, notify, callback, name); 417 if (!vq) { 418 err = -ENOMEM; 419 goto error_new_virtqueue; 420 } 421 422 vq->num_max = num; 423 424 /* Activate the queue */ 425 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 426 if (vm_dev->version == 1) { 427 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 428 429 /* 430 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 431 * that doesn't fit in 32bit, fail the setup rather than 432 * pretending to be successful. 433 */ 434 if (q_pfn >> 32) { 435 dev_err(&vdev->dev, 436 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 437 0x1ULL << (32 + PAGE_SHIFT - 30)); 438 err = -E2BIG; 439 goto error_bad_pfn; 440 } 441 442 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 443 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 444 } else { 445 u64 addr; 446 447 addr = virtqueue_get_desc_addr(vq); 448 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 449 writel((u32)(addr >> 32), 450 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 451 452 addr = virtqueue_get_avail_addr(vq); 453 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 454 writel((u32)(addr >> 32), 455 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 456 457 addr = virtqueue_get_used_addr(vq); 458 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 459 writel((u32)(addr >> 32), 460 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 461 462 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 463 } 464 465 vq->priv = info; 466 info->vq = vq; 467 468 spin_lock_irqsave(&vm_dev->lock, flags); 469 list_add(&info->node, &vm_dev->virtqueues); 470 spin_unlock_irqrestore(&vm_dev->lock, flags); 471 472 return vq; 473 474 error_bad_pfn: 475 vring_del_virtqueue(vq); 476 error_new_virtqueue: 477 if (vm_dev->version == 1) { 478 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 479 } else { 480 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 481 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 482 } 483 kfree(info); 484 error_kmalloc: 485 error_available: 486 return ERR_PTR(err); 487 } 488 489 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 490 struct virtqueue *vqs[], 491 vq_callback_t *callbacks[], 492 const char * const names[], 493 const bool *ctx, 494 struct irq_affinity *desc) 495 { 496 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 497 int irq = platform_get_irq(vm_dev->pdev, 0); 498 int i, err, queue_idx = 0; 499 500 if (irq < 0) 501 return irq; 502 503 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 504 dev_name(&vdev->dev), vm_dev); 505 if (err) 506 return err; 507 508 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source")) 509 enable_irq_wake(irq); 510 511 for (i = 0; i < nvqs; ++i) { 512 if (!names[i]) { 513 vqs[i] = NULL; 514 continue; 515 } 516 517 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i], 518 ctx ? ctx[i] : false); 519 if (IS_ERR(vqs[i])) { 520 vm_del_vqs(vdev); 521 return PTR_ERR(vqs[i]); 522 } 523 } 524 525 return 0; 526 } 527 528 static const char *vm_bus_name(struct virtio_device *vdev) 529 { 530 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 531 532 return vm_dev->pdev->name; 533 } 534 535 static bool vm_get_shm_region(struct virtio_device *vdev, 536 struct virtio_shm_region *region, u8 id) 537 { 538 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 539 u64 len, addr; 540 541 /* Select the region we're interested in */ 542 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 543 544 /* Read the region size */ 545 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 546 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 547 548 region->len = len; 549 550 /* Check if region length is -1. If that's the case, the shared memory 551 * region does not exist and there is no need to proceed further. 552 */ 553 if (len == ~(u64)0) 554 return false; 555 556 /* Read the region base address */ 557 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 558 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 559 560 region->addr = addr; 561 562 return true; 563 } 564 565 static const struct virtio_config_ops virtio_mmio_config_ops = { 566 .get = vm_get, 567 .set = vm_set, 568 .generation = vm_generation, 569 .get_status = vm_get_status, 570 .set_status = vm_set_status, 571 .reset = vm_reset, 572 .find_vqs = vm_find_vqs, 573 .del_vqs = vm_del_vqs, 574 .get_features = vm_get_features, 575 .finalize_features = vm_finalize_features, 576 .bus_name = vm_bus_name, 577 .get_shm_region = vm_get_shm_region, 578 .synchronize_cbs = vm_synchronize_cbs, 579 }; 580 581 #ifdef CONFIG_PM_SLEEP 582 static int virtio_mmio_freeze(struct device *dev) 583 { 584 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 585 586 return virtio_device_freeze(&vm_dev->vdev); 587 } 588 589 static int virtio_mmio_restore(struct device *dev) 590 { 591 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 592 593 if (vm_dev->version == 1) 594 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 595 596 return virtio_device_restore(&vm_dev->vdev); 597 } 598 599 static const struct dev_pm_ops virtio_mmio_pm_ops = { 600 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) 601 }; 602 #endif 603 604 static void virtio_mmio_release_dev(struct device *_d) 605 { 606 struct virtio_device *vdev = 607 container_of(_d, struct virtio_device, dev); 608 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 609 struct platform_device *pdev = vm_dev->pdev; 610 611 devm_kfree(&pdev->dev, vm_dev); 612 } 613 614 /* Platform device */ 615 616 static int virtio_mmio_probe(struct platform_device *pdev) 617 { 618 struct virtio_mmio_device *vm_dev; 619 unsigned long magic; 620 int rc; 621 622 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL); 623 if (!vm_dev) 624 return -ENOMEM; 625 626 vm_dev->vdev.dev.parent = &pdev->dev; 627 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 628 vm_dev->vdev.config = &virtio_mmio_config_ops; 629 vm_dev->pdev = pdev; 630 INIT_LIST_HEAD(&vm_dev->virtqueues); 631 spin_lock_init(&vm_dev->lock); 632 633 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 634 if (IS_ERR(vm_dev->base)) 635 return PTR_ERR(vm_dev->base); 636 637 /* Check magic value */ 638 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 639 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 640 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 641 return -ENODEV; 642 } 643 644 /* Check device version */ 645 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 646 if (vm_dev->version < 1 || vm_dev->version > 2) { 647 dev_err(&pdev->dev, "Version %ld not supported!\n", 648 vm_dev->version); 649 return -ENXIO; 650 } 651 652 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 653 if (vm_dev->vdev.id.device == 0) { 654 /* 655 * virtio-mmio device with an ID 0 is a (dummy) placeholder 656 * with no function. End probing now with no error reported. 657 */ 658 return -ENODEV; 659 } 660 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 661 662 if (vm_dev->version == 1) { 663 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 664 665 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 666 /* 667 * In the legacy case, ensure our coherently-allocated virtio 668 * ring will be at an address expressable as a 32-bit PFN. 669 */ 670 if (!rc) 671 dma_set_coherent_mask(&pdev->dev, 672 DMA_BIT_MASK(32 + PAGE_SHIFT)); 673 } else { 674 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 675 } 676 if (rc) 677 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 678 if (rc) 679 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 680 681 platform_set_drvdata(pdev, vm_dev); 682 683 rc = register_virtio_device(&vm_dev->vdev); 684 if (rc) 685 put_device(&vm_dev->vdev.dev); 686 687 return rc; 688 } 689 690 static int virtio_mmio_remove(struct platform_device *pdev) 691 { 692 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 693 unregister_virtio_device(&vm_dev->vdev); 694 695 return 0; 696 } 697 698 699 700 /* Devices list parameter */ 701 702 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 703 704 static struct device vm_cmdline_parent = { 705 .init_name = "virtio-mmio-cmdline", 706 }; 707 708 static int vm_cmdline_parent_registered; 709 static int vm_cmdline_id; 710 711 static int vm_cmdline_set(const char *device, 712 const struct kernel_param *kp) 713 { 714 int err; 715 struct resource resources[2] = {}; 716 char *str; 717 long long base, size; 718 unsigned int irq; 719 int processed, consumed = 0; 720 struct platform_device *pdev; 721 722 /* Consume "size" part of the command line parameter */ 723 size = memparse(device, &str); 724 725 /* Get "@<base>:<irq>[:<id>]" chunks */ 726 processed = sscanf(str, "@%lli:%u%n:%d%n", 727 &base, &irq, &consumed, 728 &vm_cmdline_id, &consumed); 729 730 /* 731 * sscanf() must process at least 2 chunks; also there 732 * must be no extra characters after the last chunk, so 733 * str[consumed] must be '\0' 734 */ 735 if (processed < 2 || str[consumed] || irq == 0) 736 return -EINVAL; 737 738 resources[0].flags = IORESOURCE_MEM; 739 resources[0].start = base; 740 resources[0].end = base + size - 1; 741 742 resources[1].flags = IORESOURCE_IRQ; 743 resources[1].start = resources[1].end = irq; 744 745 if (!vm_cmdline_parent_registered) { 746 err = device_register(&vm_cmdline_parent); 747 if (err) { 748 put_device(&vm_cmdline_parent); 749 pr_err("Failed to register parent device!\n"); 750 return err; 751 } 752 vm_cmdline_parent_registered = 1; 753 } 754 755 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", 756 vm_cmdline_id, 757 (unsigned long long)resources[0].start, 758 (unsigned long long)resources[0].end, 759 (int)resources[1].start); 760 761 pdev = platform_device_register_resndata(&vm_cmdline_parent, 762 "virtio-mmio", vm_cmdline_id++, 763 resources, ARRAY_SIZE(resources), NULL, 0); 764 765 return PTR_ERR_OR_ZERO(pdev); 766 } 767 768 static int vm_cmdline_get_device(struct device *dev, void *data) 769 { 770 char *buffer = data; 771 unsigned int len = strlen(buffer); 772 struct platform_device *pdev = to_platform_device(dev); 773 774 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", 775 pdev->resource[0].end - pdev->resource[0].start + 1ULL, 776 (unsigned long long)pdev->resource[0].start, 777 (unsigned long long)pdev->resource[1].start, 778 pdev->id); 779 return 0; 780 } 781 782 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 783 { 784 buffer[0] = '\0'; 785 device_for_each_child(&vm_cmdline_parent, buffer, 786 vm_cmdline_get_device); 787 return strlen(buffer) + 1; 788 } 789 790 static const struct kernel_param_ops vm_cmdline_param_ops = { 791 .set = vm_cmdline_set, 792 .get = vm_cmdline_get, 793 }; 794 795 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 796 797 static int vm_unregister_cmdline_device(struct device *dev, 798 void *data) 799 { 800 platform_device_unregister(to_platform_device(dev)); 801 802 return 0; 803 } 804 805 static void vm_unregister_cmdline_devices(void) 806 { 807 if (vm_cmdline_parent_registered) { 808 device_for_each_child(&vm_cmdline_parent, NULL, 809 vm_unregister_cmdline_device); 810 device_unregister(&vm_cmdline_parent); 811 vm_cmdline_parent_registered = 0; 812 } 813 } 814 815 #else 816 817 static void vm_unregister_cmdline_devices(void) 818 { 819 } 820 821 #endif 822 823 /* Platform driver */ 824 825 static const struct of_device_id virtio_mmio_match[] = { 826 { .compatible = "virtio,mmio", }, 827 {}, 828 }; 829 MODULE_DEVICE_TABLE(of, virtio_mmio_match); 830 831 #ifdef CONFIG_ACPI 832 static const struct acpi_device_id virtio_mmio_acpi_match[] = { 833 { "LNRO0005", }, 834 { } 835 }; 836 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 837 #endif 838 839 static struct platform_driver virtio_mmio_driver = { 840 .probe = virtio_mmio_probe, 841 .remove = virtio_mmio_remove, 842 .driver = { 843 .name = "virtio-mmio", 844 .of_match_table = virtio_mmio_match, 845 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 846 #ifdef CONFIG_PM_SLEEP 847 .pm = &virtio_mmio_pm_ops, 848 #endif 849 }, 850 }; 851 852 static int __init virtio_mmio_init(void) 853 { 854 return platform_driver_register(&virtio_mmio_driver); 855 } 856 857 static void __exit virtio_mmio_exit(void) 858 { 859 platform_driver_unregister(&virtio_mmio_driver); 860 vm_unregister_cmdline_devices(); 861 } 862 863 module_init(virtio_mmio_init); 864 module_exit(virtio_mmio_exit); 865 866 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 867 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 868 MODULE_LICENSE("GPL"); 869