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/delay.h> 59 #include <linux/dma-mapping.h> 60 #include <linux/highmem.h> 61 #include <linux/interrupt.h> 62 #include <linux/io.h> 63 #include <linux/list.h> 64 #include <linux/module.h> 65 #include <linux/of.h> 66 #include <linux/platform_device.h> 67 #include <linux/pm.h> 68 #include <linux/slab.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 93 /* Configuration interface */ 94 95 static u64 vm_get_features(struct virtio_device *vdev) 96 { 97 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 98 u64 features; 99 100 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 101 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 102 features <<= 32; 103 104 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 105 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 106 107 return features; 108 } 109 110 static int vm_finalize_features(struct virtio_device *vdev) 111 { 112 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 113 114 /* Give virtio_ring a chance to accept features. */ 115 vring_transport_features(vdev); 116 117 /* Make sure there are no mixed devices */ 118 if (vm_dev->version >= 2 && 119 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) { 120 dev_err(&vdev->dev, "New virtio-mmio devices (version >= 2) must provide VIRTIO_F_VERSION_1 feature!\n"); 121 return -EINVAL; 122 } 123 124 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 125 writel((u32)(vdev->features >> 32), 126 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 127 128 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 129 writel((u32)vdev->features, 130 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 131 132 return 0; 133 } 134 135 static void vm_get(struct virtio_device *vdev, unsigned int offset, 136 void *buf, unsigned int len) 137 { 138 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 139 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 140 u8 b; 141 __le16 w; 142 __le32 l; 143 144 if (vm_dev->version == 1) { 145 u8 *ptr = buf; 146 int i; 147 148 for (i = 0; i < len; i++) 149 ptr[i] = readb(base + offset + i); 150 return; 151 } 152 153 switch (len) { 154 case 1: 155 b = readb(base + offset); 156 memcpy(buf, &b, sizeof b); 157 break; 158 case 2: 159 w = cpu_to_le16(readw(base + offset)); 160 memcpy(buf, &w, sizeof w); 161 break; 162 case 4: 163 l = cpu_to_le32(readl(base + offset)); 164 memcpy(buf, &l, sizeof l); 165 break; 166 case 8: 167 l = cpu_to_le32(readl(base + offset)); 168 memcpy(buf, &l, sizeof l); 169 l = cpu_to_le32(ioread32(base + offset + sizeof l)); 170 memcpy(buf + sizeof l, &l, sizeof l); 171 break; 172 default: 173 BUG(); 174 } 175 } 176 177 static void vm_set(struct virtio_device *vdev, unsigned int offset, 178 const void *buf, unsigned int len) 179 { 180 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 181 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 182 u8 b; 183 __le16 w; 184 __le32 l; 185 186 if (vm_dev->version == 1) { 187 const u8 *ptr = buf; 188 int i; 189 190 for (i = 0; i < len; i++) 191 writeb(ptr[i], base + offset + i); 192 193 return; 194 } 195 196 switch (len) { 197 case 1: 198 memcpy(&b, buf, sizeof b); 199 writeb(b, base + offset); 200 break; 201 case 2: 202 memcpy(&w, buf, sizeof w); 203 writew(le16_to_cpu(w), base + offset); 204 break; 205 case 4: 206 memcpy(&l, buf, sizeof l); 207 writel(le32_to_cpu(l), base + offset); 208 break; 209 case 8: 210 memcpy(&l, buf, sizeof l); 211 writel(le32_to_cpu(l), base + offset); 212 memcpy(&l, buf + sizeof l, sizeof l); 213 writel(le32_to_cpu(l), base + offset + sizeof l); 214 break; 215 default: 216 BUG(); 217 } 218 } 219 220 static u32 vm_generation(struct virtio_device *vdev) 221 { 222 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 223 224 if (vm_dev->version == 1) 225 return 0; 226 else 227 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION); 228 } 229 230 static u8 vm_get_status(struct virtio_device *vdev) 231 { 232 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 233 234 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff; 235 } 236 237 static void vm_set_status(struct virtio_device *vdev, u8 status) 238 { 239 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 240 241 /* We should never be setting status to 0. */ 242 BUG_ON(status == 0); 243 244 /* 245 * Per memory-barriers.txt, wmb() is not needed to guarantee 246 * that the cache coherent memory writes have completed 247 * before writing to the MMIO region. 248 */ 249 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS); 250 } 251 252 static void vm_reset(struct virtio_device *vdev) 253 { 254 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 255 256 /* 0 status means a reset. */ 257 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS); 258 259 if (vm_dev->version >= 3) { 260 /* Wait for reset to complete. */ 261 while (vm_get_status(vdev)) 262 fsleep(1000); 263 } 264 } 265 266 267 268 /* Transport interface */ 269 270 /* the notify function used when creating a virt queue */ 271 static bool vm_notify(struct virtqueue *vq) 272 { 273 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 274 275 /* We write the queue's selector into the notification register to 276 * signal the other end */ 277 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 278 return true; 279 } 280 281 static bool vm_notify_with_data(struct virtqueue *vq) 282 { 283 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 284 u32 data = vring_notification_data(vq); 285 286 writel(data, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 287 288 return true; 289 } 290 291 /* Notify all virtqueues on an interrupt. */ 292 static irqreturn_t vm_interrupt(int irq, void *opaque) 293 { 294 struct virtio_mmio_device *vm_dev = opaque; 295 struct virtqueue *vq; 296 unsigned long status; 297 irqreturn_t ret = IRQ_NONE; 298 299 /* Read and acknowledge interrupts */ 300 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); 301 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); 302 303 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { 304 virtio_config_changed(&vm_dev->vdev); 305 ret = IRQ_HANDLED; 306 } 307 308 if (likely(status & VIRTIO_MMIO_INT_VRING)) { 309 virtio_device_for_each_vq(&vm_dev->vdev, vq) 310 ret |= vring_interrupt(irq, vq); 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 unsigned int index = vq->index; 322 323 /* Select and deactivate the queue */ 324 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 325 if (vm_dev->version == 1) { 326 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 327 } else { 328 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 329 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 330 } 331 332 vring_del_virtqueue(vq); 333 } 334 335 static void vm_del_vqs(struct virtio_device *vdev) 336 { 337 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 338 struct virtqueue *vq, *n; 339 340 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 341 vm_del_vq(vq); 342 343 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); 344 } 345 346 static void vm_synchronize_cbs(struct virtio_device *vdev) 347 { 348 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 349 350 synchronize_irq(platform_get_irq(vm_dev->pdev, 0)); 351 } 352 353 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index, 354 void (*callback)(struct virtqueue *vq), 355 const char *name, bool ctx) 356 { 357 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 358 bool (*notify)(struct virtqueue *vq); 359 struct virtqueue *vq; 360 unsigned int num; 361 int err; 362 363 if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA)) 364 notify = vm_notify_with_data; 365 else 366 notify = vm_notify; 367 368 if (!name) 369 return NULL; 370 371 /* Select the queue we're interested in */ 372 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 373 374 /* Queue shouldn't already be set up. */ 375 if (readl(vm_dev->base + (vm_dev->version == 1 ? 376 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) { 377 err = -ENOENT; 378 goto error_available; 379 } 380 381 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); 382 if (num == 0) { 383 err = -ENOENT; 384 goto error_new_virtqueue; 385 } 386 387 /* Create the vring */ 388 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, 389 true, true, ctx, notify, callback, name); 390 if (!vq) { 391 err = -ENOMEM; 392 goto error_new_virtqueue; 393 } 394 395 vq->num_max = num; 396 397 /* Activate the queue */ 398 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 399 if (vm_dev->version == 1) { 400 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 401 402 /* 403 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 404 * that doesn't fit in 32bit, fail the setup rather than 405 * pretending to be successful. 406 */ 407 if (q_pfn >> 32) { 408 dev_err(&vdev->dev, 409 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 410 0x1ULL << (32 + PAGE_SHIFT - 30)); 411 err = -E2BIG; 412 goto error_bad_pfn; 413 } 414 415 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 416 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 417 } else { 418 u64 addr; 419 420 addr = virtqueue_get_desc_addr(vq); 421 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 422 writel((u32)(addr >> 32), 423 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 424 425 addr = virtqueue_get_avail_addr(vq); 426 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 427 writel((u32)(addr >> 32), 428 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 429 430 addr = virtqueue_get_used_addr(vq); 431 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 432 writel((u32)(addr >> 32), 433 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 434 435 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 436 } 437 438 return vq; 439 440 error_bad_pfn: 441 vring_del_virtqueue(vq); 442 error_new_virtqueue: 443 if (vm_dev->version == 1) { 444 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 445 } else { 446 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 447 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 448 } 449 error_available: 450 return ERR_PTR(err); 451 } 452 453 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 454 struct virtqueue *vqs[], 455 struct virtqueue_info vqs_info[], 456 struct irq_affinity *desc) 457 { 458 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 459 int irq = platform_get_irq(vm_dev->pdev, 0); 460 int i, err, queue_idx = 0; 461 462 if (irq < 0) 463 return irq; 464 465 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 466 dev_name(&vdev->dev), vm_dev); 467 if (err) 468 return err; 469 470 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source")) 471 enable_irq_wake(irq); 472 473 for (i = 0; i < nvqs; ++i) { 474 struct virtqueue_info *vqi = &vqs_info[i]; 475 476 if (!vqi->name) { 477 vqs[i] = NULL; 478 continue; 479 } 480 481 vqs[i] = vm_setup_vq(vdev, queue_idx++, vqi->callback, 482 vqi->name, vqi->ctx); 483 if (IS_ERR(vqs[i])) { 484 vm_del_vqs(vdev); 485 return PTR_ERR(vqs[i]); 486 } 487 } 488 489 return 0; 490 } 491 492 static const char *vm_bus_name(struct virtio_device *vdev) 493 { 494 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 495 496 return vm_dev->pdev->name; 497 } 498 499 static bool vm_get_shm_region(struct virtio_device *vdev, 500 struct virtio_shm_region *region, u8 id) 501 { 502 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 503 u64 len, addr; 504 505 /* Select the region we're interested in */ 506 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 507 508 /* Read the region size */ 509 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 510 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 511 512 region->len = len; 513 514 /* Check if region length is -1. If that's the case, the shared memory 515 * region does not exist and there is no need to proceed further. 516 */ 517 if (len == ~(u64)0) 518 return false; 519 520 /* Read the region base address */ 521 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 522 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 523 524 region->addr = addr; 525 526 return true; 527 } 528 529 static const struct virtio_config_ops virtio_mmio_config_ops = { 530 .get = vm_get, 531 .set = vm_set, 532 .generation = vm_generation, 533 .get_status = vm_get_status, 534 .set_status = vm_set_status, 535 .reset = vm_reset, 536 .find_vqs = vm_find_vqs, 537 .del_vqs = vm_del_vqs, 538 .get_features = vm_get_features, 539 .finalize_features = vm_finalize_features, 540 .bus_name = vm_bus_name, 541 .get_shm_region = vm_get_shm_region, 542 .synchronize_cbs = vm_synchronize_cbs, 543 }; 544 545 #ifdef CONFIG_PM_SLEEP 546 static int virtio_mmio_freeze(struct device *dev) 547 { 548 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 549 550 return virtio_device_freeze(&vm_dev->vdev); 551 } 552 553 static int virtio_mmio_restore(struct device *dev) 554 { 555 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 556 557 if (vm_dev->version == 1) 558 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 559 560 return virtio_device_restore(&vm_dev->vdev); 561 } 562 563 static const struct dev_pm_ops virtio_mmio_pm_ops = { 564 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) 565 }; 566 #endif 567 568 static void virtio_mmio_release_dev(struct device *_d) 569 { 570 struct virtio_device *vdev = 571 container_of(_d, struct virtio_device, dev); 572 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 573 574 kfree(vm_dev); 575 } 576 577 /* Platform device */ 578 579 static int virtio_mmio_probe(struct platform_device *pdev) 580 { 581 struct virtio_mmio_device *vm_dev; 582 unsigned long magic; 583 int rc; 584 585 vm_dev = kzalloc_obj(*vm_dev); 586 if (!vm_dev) 587 return -ENOMEM; 588 589 vm_dev->vdev.dev.parent = &pdev->dev; 590 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 591 vm_dev->vdev.config = &virtio_mmio_config_ops; 592 vm_dev->pdev = pdev; 593 594 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 595 if (IS_ERR(vm_dev->base)) { 596 rc = PTR_ERR(vm_dev->base); 597 goto free_vm_dev; 598 } 599 600 /* Check magic value */ 601 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 602 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 603 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 604 rc = -ENODEV; 605 goto free_vm_dev; 606 } 607 608 /* Check device version */ 609 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 610 if (vm_dev->version < 1 || vm_dev->version > 3) { 611 dev_err(&pdev->dev, "Version %ld not supported!\n", 612 vm_dev->version); 613 rc = -ENXIO; 614 goto free_vm_dev; 615 } 616 617 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 618 if (vm_dev->vdev.id.device == 0) { 619 /* 620 * virtio-mmio device with an ID 0 is a (dummy) placeholder 621 * with no function. End probing now with no error reported. 622 */ 623 rc = -ENODEV; 624 goto free_vm_dev; 625 } 626 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 627 628 if (vm_dev->version == 1) { 629 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 630 631 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 632 /* 633 * In the legacy case, ensure our coherently-allocated virtio 634 * ring will be at an address expressable as a 32-bit PFN. 635 */ 636 if (!rc) 637 dma_set_coherent_mask(&pdev->dev, 638 DMA_BIT_MASK(32 + PAGE_SHIFT)); 639 } else { 640 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 641 } 642 if (rc) 643 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 644 if (rc) 645 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 646 647 platform_set_drvdata(pdev, vm_dev); 648 649 rc = register_virtio_device(&vm_dev->vdev); 650 if (rc) 651 put_device(&vm_dev->vdev.dev); 652 653 return rc; 654 655 free_vm_dev: 656 kfree(vm_dev); 657 return rc; 658 } 659 660 static void virtio_mmio_remove(struct platform_device *pdev) 661 { 662 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 663 unregister_virtio_device(&vm_dev->vdev); 664 } 665 666 667 668 /* Devices list parameter */ 669 670 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 671 672 static struct device *vm_cmdline_parent; 673 674 static int vm_cmdline_parent_registered; 675 static int vm_cmdline_id; 676 677 static int vm_cmdline_set(const char *device, 678 const struct kernel_param *kp) 679 { 680 struct resource resources[2] = {}; 681 char *str; 682 long long base, size; 683 unsigned int irq; 684 int processed, consumed = 0; 685 struct platform_device *pdev; 686 687 /* Consume "size" part of the command line parameter */ 688 size = memparse(device, &str); 689 690 /* Get "@<base>:<irq>[:<id>]" chunks */ 691 processed = sscanf(str, "@%lli:%u%n:%d%n", 692 &base, &irq, &consumed, 693 &vm_cmdline_id, &consumed); 694 695 /* 696 * sscanf() must process at least 2 chunks; also there 697 * must be no extra characters after the last chunk, so 698 * str[consumed] must be '\0' 699 */ 700 if (processed < 2 || str[consumed] || irq == 0) 701 return -EINVAL; 702 703 resources[0].flags = IORESOURCE_MEM; 704 resources[0].start = base; 705 resources[0].end = base + size - 1; 706 707 resources[1].flags = IORESOURCE_IRQ; 708 resources[1].start = resources[1].end = irq; 709 710 if (!vm_cmdline_parent_registered) { 711 vm_cmdline_parent = __root_device_register("virtio-mmio-cmdline", NULL); 712 if (IS_ERR(vm_cmdline_parent)) { 713 pr_err("Failed to register parent device!\n"); 714 return PTR_ERR(vm_cmdline_parent); 715 } 716 vm_cmdline_parent_registered = 1; 717 } 718 719 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", 720 vm_cmdline_id, 721 (unsigned long long)resources[0].start, 722 (unsigned long long)resources[0].end, 723 (int)resources[1].start); 724 725 pdev = platform_device_register_resndata(vm_cmdline_parent, 726 "virtio-mmio", vm_cmdline_id++, 727 resources, ARRAY_SIZE(resources), NULL, 0); 728 729 return PTR_ERR_OR_ZERO(pdev); 730 } 731 732 static int vm_cmdline_get_device(struct device *dev, void *data) 733 { 734 char *buffer = data; 735 unsigned int len = strlen(buffer); 736 struct platform_device *pdev = to_platform_device(dev); 737 738 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", 739 pdev->resource[0].end - pdev->resource[0].start + 1ULL, 740 (unsigned long long)pdev->resource[0].start, 741 (unsigned long long)pdev->resource[1].start, 742 pdev->id); 743 return 0; 744 } 745 746 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 747 { 748 buffer[0] = '\0'; 749 750 if (vm_cmdline_parent_registered) { 751 device_for_each_child(vm_cmdline_parent, buffer, 752 vm_cmdline_get_device); 753 } 754 755 return strlen(buffer) + 1; 756 } 757 758 static const struct kernel_param_ops vm_cmdline_param_ops = { 759 .set = vm_cmdline_set, 760 .get = vm_cmdline_get, 761 }; 762 763 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 764 765 static int vm_unregister_cmdline_device(struct device *dev, 766 void *data) 767 { 768 platform_device_unregister(to_platform_device(dev)); 769 770 return 0; 771 } 772 773 static void vm_unregister_cmdline_devices(void) 774 { 775 if (vm_cmdline_parent_registered) { 776 device_for_each_child(vm_cmdline_parent, NULL, 777 vm_unregister_cmdline_device); 778 root_device_unregister(vm_cmdline_parent); 779 vm_cmdline_parent_registered = 0; 780 } 781 } 782 783 #else 784 785 static void vm_unregister_cmdline_devices(void) 786 { 787 } 788 789 #endif 790 791 /* Platform driver */ 792 793 static const struct of_device_id virtio_mmio_match[] = { 794 { .compatible = "virtio,mmio", }, 795 {}, 796 }; 797 MODULE_DEVICE_TABLE(of, virtio_mmio_match); 798 799 #ifdef CONFIG_ACPI 800 static const struct acpi_device_id virtio_mmio_acpi_match[] = { 801 { "LNRO0005", }, 802 { } 803 }; 804 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 805 #endif 806 807 static struct platform_driver virtio_mmio_driver = { 808 .probe = virtio_mmio_probe, 809 .remove = virtio_mmio_remove, 810 .driver = { 811 .name = "virtio-mmio", 812 .of_match_table = virtio_mmio_match, 813 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 814 #ifdef CONFIG_PM_SLEEP 815 .pm = &virtio_mmio_pm_ops, 816 #endif 817 }, 818 }; 819 820 static int __init virtio_mmio_init(void) 821 { 822 return platform_driver_register(&virtio_mmio_driver); 823 } 824 825 static void __exit virtio_mmio_exit(void) 826 { 827 platform_driver_unregister(&virtio_mmio_driver); 828 vm_unregister_cmdline_devices(); 829 } 830 831 module_init(virtio_mmio_init); 832 module_exit(virtio_mmio_exit); 833 834 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 835 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 836 MODULE_LICENSE("GPL"); 837