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 /* True if enable_irq_wake() succeeded for the shared IRQ. */ 93 bool wake_irq_enabled; 94 }; 95 96 /* Configuration interface */ 97 98 static u64 vm_get_features(struct virtio_device *vdev) 99 { 100 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 101 u64 features; 102 103 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 104 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 105 features <<= 32; 106 107 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); 108 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); 109 110 return features; 111 } 112 113 static int vm_finalize_features(struct virtio_device *vdev) 114 { 115 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 116 117 /* Give virtio_ring a chance to accept features. */ 118 vring_transport_features(vdev); 119 120 /* Make sure there are no mixed devices */ 121 if (vm_dev->version >= 2 && 122 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) { 123 dev_err(&vdev->dev, "New virtio-mmio devices (version >= 2) must provide VIRTIO_F_VERSION_1 feature!\n"); 124 return -EINVAL; 125 } 126 127 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 128 writel((u32)(vdev->features >> 32), 129 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 130 131 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); 132 writel((u32)vdev->features, 133 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); 134 135 return 0; 136 } 137 138 static void vm_get(struct virtio_device *vdev, unsigned int offset, 139 void *buf, unsigned int len) 140 { 141 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 142 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 143 u8 b; 144 __le16 w; 145 __le32 l; 146 147 if (vm_dev->version == 1) { 148 u8 *ptr = buf; 149 int i; 150 151 for (i = 0; i < len; i++) 152 ptr[i] = readb(base + offset + i); 153 return; 154 } 155 156 switch (len) { 157 case 1: 158 b = readb(base + offset); 159 memcpy(buf, &b, sizeof b); 160 break; 161 case 2: 162 w = cpu_to_le16(readw(base + offset)); 163 memcpy(buf, &w, sizeof w); 164 break; 165 case 4: 166 l = cpu_to_le32(readl(base + offset)); 167 memcpy(buf, &l, sizeof l); 168 break; 169 case 8: 170 l = cpu_to_le32(readl(base + offset)); 171 memcpy(buf, &l, sizeof l); 172 l = cpu_to_le32(ioread32(base + offset + sizeof l)); 173 memcpy(buf + sizeof l, &l, sizeof l); 174 break; 175 default: 176 BUG(); 177 } 178 } 179 180 static void vm_set(struct virtio_device *vdev, unsigned int offset, 181 const void *buf, unsigned int len) 182 { 183 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 184 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 185 u8 b; 186 __le16 w; 187 __le32 l; 188 189 if (vm_dev->version == 1) { 190 const u8 *ptr = buf; 191 int i; 192 193 for (i = 0; i < len; i++) 194 writeb(ptr[i], base + offset + i); 195 196 return; 197 } 198 199 switch (len) { 200 case 1: 201 memcpy(&b, buf, sizeof b); 202 writeb(b, base + offset); 203 break; 204 case 2: 205 memcpy(&w, buf, sizeof w); 206 writew(le16_to_cpu(w), base + offset); 207 break; 208 case 4: 209 memcpy(&l, buf, sizeof l); 210 writel(le32_to_cpu(l), base + offset); 211 break; 212 case 8: 213 memcpy(&l, buf, sizeof l); 214 writel(le32_to_cpu(l), base + offset); 215 memcpy(&l, buf + sizeof l, sizeof l); 216 writel(le32_to_cpu(l), base + offset + sizeof l); 217 break; 218 default: 219 BUG(); 220 } 221 } 222 223 static u32 vm_generation(struct virtio_device *vdev) 224 { 225 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 226 227 if (vm_dev->version == 1) 228 return 0; 229 else 230 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION); 231 } 232 233 static u8 vm_get_status(struct virtio_device *vdev) 234 { 235 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 236 237 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff; 238 } 239 240 static void vm_set_status(struct virtio_device *vdev, u8 status) 241 { 242 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 243 244 /* We should never be setting status to 0. */ 245 BUG_ON(status == 0); 246 247 /* 248 * Per memory-barriers.txt, wmb() is not needed to guarantee 249 * that the cache coherent memory writes have completed 250 * before writing to the MMIO region. 251 */ 252 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS); 253 } 254 255 static void vm_reset(struct virtio_device *vdev) 256 { 257 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 258 259 /* 0 status means a reset. */ 260 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS); 261 262 if (vm_dev->version >= 3) { 263 /* Wait for reset to complete. */ 264 while (vm_get_status(vdev)) 265 fsleep(1000); 266 } 267 } 268 269 270 271 /* Transport interface */ 272 273 /* the notify function used when creating a virt queue */ 274 static bool vm_notify(struct virtqueue *vq) 275 { 276 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 277 278 /* We write the queue's selector into the notification register to 279 * signal the other end */ 280 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 281 return true; 282 } 283 284 static bool vm_notify_with_data(struct virtqueue *vq) 285 { 286 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 287 u32 data = vring_notification_data(vq); 288 289 writel(data, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 290 291 return true; 292 } 293 294 /* Notify all virtqueues on an interrupt. */ 295 static irqreturn_t vm_interrupt(int irq, void *opaque) 296 { 297 struct virtio_mmio_device *vm_dev = opaque; 298 struct virtqueue *vq; 299 unsigned long status; 300 irqreturn_t ret = IRQ_NONE; 301 302 /* Read and acknowledge interrupts */ 303 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); 304 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); 305 306 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { 307 virtio_config_changed(&vm_dev->vdev); 308 ret = IRQ_HANDLED; 309 } 310 311 if (likely(status & VIRTIO_MMIO_INT_VRING)) { 312 virtio_device_for_each_vq(&vm_dev->vdev, vq) 313 ret |= vring_interrupt(irq, vq); 314 } 315 316 return ret; 317 } 318 319 320 321 static void vm_del_vq(struct virtqueue *vq) 322 { 323 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 324 unsigned int index = vq->index; 325 326 /* Select and deactivate the queue */ 327 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 328 if (vm_dev->version == 1) { 329 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 330 } else { 331 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 332 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 333 } 334 335 vring_del_virtqueue(vq); 336 } 337 338 static void vm_del_vqs(struct virtio_device *vdev) 339 { 340 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 341 struct virtqueue *vq, *n; 342 int irq = platform_get_irq(vm_dev->pdev, 0); 343 344 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 345 vm_del_vq(vq); 346 347 if (vm_dev->wake_irq_enabled) { 348 disable_irq_wake(irq); 349 vm_dev->wake_irq_enabled = false; 350 } 351 352 free_irq(irq, vm_dev); 353 } 354 355 static void vm_synchronize_cbs(struct virtio_device *vdev) 356 { 357 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 358 359 synchronize_irq(platform_get_irq(vm_dev->pdev, 0)); 360 } 361 362 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index, 363 void (*callback)(struct virtqueue *vq), 364 const char *name, bool ctx) 365 { 366 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 367 bool (*notify)(struct virtqueue *vq); 368 struct virtqueue *vq; 369 unsigned int num; 370 int err; 371 372 if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA)) 373 notify = vm_notify_with_data; 374 else 375 notify = vm_notify; 376 377 if (!name) 378 return NULL; 379 380 /* Select the queue we're interested in */ 381 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 382 383 /* Queue shouldn't already be set up. */ 384 if (readl(vm_dev->base + (vm_dev->version == 1 ? 385 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) { 386 err = -ENOENT; 387 goto error_available; 388 } 389 390 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); 391 if (num == 0) { 392 err = -ENOENT; 393 goto error_new_virtqueue; 394 } 395 396 /* Create the vring */ 397 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, 398 true, true, ctx, notify, callback, name); 399 if (!vq) { 400 err = -ENOMEM; 401 goto error_new_virtqueue; 402 } 403 404 vq->num_max = num; 405 406 /* Activate the queue */ 407 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 408 if (vm_dev->version == 1) { 409 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 410 411 /* 412 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 413 * that doesn't fit in 32bit, fail the setup rather than 414 * pretending to be successful. 415 */ 416 if (q_pfn >> 32) { 417 dev_err(&vdev->dev, 418 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 419 0x1ULL << (32 + PAGE_SHIFT - 30)); 420 err = -E2BIG; 421 goto error_bad_pfn; 422 } 423 424 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 425 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 426 } else { 427 u64 addr; 428 429 addr = virtqueue_get_desc_addr(vq); 430 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 431 writel((u32)(addr >> 32), 432 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 433 434 addr = virtqueue_get_avail_addr(vq); 435 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 436 writel((u32)(addr >> 32), 437 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 438 439 addr = virtqueue_get_used_addr(vq); 440 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 441 writel((u32)(addr >> 32), 442 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 443 444 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 445 } 446 447 return vq; 448 449 error_bad_pfn: 450 vring_del_virtqueue(vq); 451 error_new_virtqueue: 452 if (vm_dev->version == 1) { 453 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 454 } else { 455 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 456 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 457 } 458 error_available: 459 return ERR_PTR(err); 460 } 461 462 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 463 struct virtqueue *vqs[], 464 struct virtqueue_info vqs_info[], 465 struct irq_affinity *desc) 466 { 467 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 468 int irq = platform_get_irq(vm_dev->pdev, 0); 469 int i, err, queue_idx = 0; 470 471 if (irq < 0) 472 return irq; 473 474 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 475 dev_name(&vdev->dev), vm_dev); 476 if (err) 477 return err; 478 479 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source") && 480 !enable_irq_wake(irq)) 481 vm_dev->wake_irq_enabled = true; 482 483 for (i = 0; i < nvqs; ++i) { 484 struct virtqueue_info *vqi = &vqs_info[i]; 485 486 if (!vqi->name) { 487 vqs[i] = NULL; 488 continue; 489 } 490 491 vqs[i] = vm_setup_vq(vdev, queue_idx++, vqi->callback, 492 vqi->name, vqi->ctx); 493 if (IS_ERR(vqs[i])) { 494 vm_del_vqs(vdev); 495 return PTR_ERR(vqs[i]); 496 } 497 } 498 499 return 0; 500 } 501 502 static const char *vm_bus_name(struct virtio_device *vdev) 503 { 504 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 505 506 return vm_dev->pdev->name; 507 } 508 509 static bool vm_get_shm_region(struct virtio_device *vdev, 510 struct virtio_shm_region *region, u8 id) 511 { 512 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 513 u64 len, addr; 514 515 /* Select the region we're interested in */ 516 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 517 518 /* Read the region size */ 519 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 520 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 521 522 region->len = len; 523 524 /* Check if region length is -1. If that's the case, the shared memory 525 * region does not exist and there is no need to proceed further. 526 */ 527 if (len == ~(u64)0) 528 return false; 529 530 /* Read the region base address */ 531 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 532 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 533 534 region->addr = addr; 535 536 return true; 537 } 538 539 static const struct virtio_config_ops virtio_mmio_config_ops = { 540 .get = vm_get, 541 .set = vm_set, 542 .generation = vm_generation, 543 .get_status = vm_get_status, 544 .set_status = vm_set_status, 545 .reset = vm_reset, 546 .find_vqs = vm_find_vqs, 547 .del_vqs = vm_del_vqs, 548 .get_features = vm_get_features, 549 .finalize_features = vm_finalize_features, 550 .bus_name = vm_bus_name, 551 .get_shm_region = vm_get_shm_region, 552 .synchronize_cbs = vm_synchronize_cbs, 553 }; 554 555 #ifdef CONFIG_PM_SLEEP 556 static int virtio_mmio_freeze(struct device *dev) 557 { 558 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 559 560 return virtio_device_freeze(&vm_dev->vdev); 561 } 562 563 static int virtio_mmio_restore(struct device *dev) 564 { 565 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 566 567 if (vm_dev->version == 1) 568 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 569 570 return virtio_device_restore(&vm_dev->vdev); 571 } 572 573 static const struct dev_pm_ops virtio_mmio_pm_ops = { 574 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) 575 }; 576 #endif 577 578 static void virtio_mmio_release_dev(struct device *_d) 579 { 580 struct virtio_device *vdev = 581 container_of(_d, struct virtio_device, dev); 582 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 583 584 kfree(vm_dev); 585 } 586 587 /* Platform device */ 588 589 static int virtio_mmio_probe(struct platform_device *pdev) 590 { 591 struct virtio_mmio_device *vm_dev; 592 unsigned long magic; 593 int rc; 594 595 vm_dev = kzalloc_obj(*vm_dev); 596 if (!vm_dev) 597 return -ENOMEM; 598 599 vm_dev->vdev.dev.parent = &pdev->dev; 600 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 601 vm_dev->vdev.config = &virtio_mmio_config_ops; 602 vm_dev->pdev = pdev; 603 604 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 605 if (IS_ERR(vm_dev->base)) { 606 rc = PTR_ERR(vm_dev->base); 607 goto free_vm_dev; 608 } 609 610 /* Check magic value */ 611 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 612 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 613 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 614 rc = -ENODEV; 615 goto free_vm_dev; 616 } 617 618 /* Check device version */ 619 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 620 if (vm_dev->version < 1 || vm_dev->version > 3) { 621 dev_err(&pdev->dev, "Version %ld not supported!\n", 622 vm_dev->version); 623 rc = -ENXIO; 624 goto free_vm_dev; 625 } 626 627 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 628 if (vm_dev->vdev.id.device == 0) { 629 /* 630 * virtio-mmio device with an ID 0 is a (dummy) placeholder 631 * with no function. End probing now with no error reported. 632 */ 633 rc = -ENODEV; 634 goto free_vm_dev; 635 } 636 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 637 638 if (vm_dev->version == 1) { 639 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 640 641 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 642 /* 643 * In the legacy case, ensure our coherently-allocated virtio 644 * ring will be at an address expressable as a 32-bit PFN. 645 */ 646 if (!rc) 647 dma_set_coherent_mask(&pdev->dev, 648 DMA_BIT_MASK(32 + PAGE_SHIFT)); 649 } else { 650 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 651 } 652 if (rc) 653 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 654 if (rc) 655 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 656 657 platform_set_drvdata(pdev, vm_dev); 658 659 rc = register_virtio_device(&vm_dev->vdev); 660 if (rc) 661 put_device(&vm_dev->vdev.dev); 662 663 return rc; 664 665 free_vm_dev: 666 kfree(vm_dev); 667 return rc; 668 } 669 670 static void virtio_mmio_remove(struct platform_device *pdev) 671 { 672 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 673 unregister_virtio_device(&vm_dev->vdev); 674 } 675 676 677 678 /* Devices list parameter */ 679 680 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 681 682 static struct device *vm_cmdline_parent; 683 684 static int vm_cmdline_parent_registered; 685 static int vm_cmdline_id; 686 687 static int vm_cmdline_set(const char *device, 688 const struct kernel_param *kp) 689 { 690 struct resource resources[2] = {}; 691 char *str; 692 long long base, size; 693 unsigned int irq; 694 int processed, consumed = 0; 695 struct platform_device *pdev; 696 697 /* Consume "size" part of the command line parameter */ 698 size = memparse(device, &str); 699 700 /* Get "@<base>:<irq>[:<id>]" chunks */ 701 processed = sscanf(str, "@%lli:%u%n:%d%n", 702 &base, &irq, &consumed, 703 &vm_cmdline_id, &consumed); 704 705 /* 706 * sscanf() must process at least 2 chunks; also there 707 * must be no extra characters after the last chunk, so 708 * str[consumed] must be '\0' 709 */ 710 if (processed < 2 || str[consumed] || irq == 0) 711 return -EINVAL; 712 713 resources[0].flags = IORESOURCE_MEM; 714 resources[0].start = base; 715 resources[0].end = base + size - 1; 716 717 resources[1].flags = IORESOURCE_IRQ; 718 resources[1].start = resources[1].end = irq; 719 720 if (!vm_cmdline_parent_registered) { 721 vm_cmdline_parent = __root_device_register("virtio-mmio-cmdline", NULL); 722 if (IS_ERR(vm_cmdline_parent)) { 723 pr_err("Failed to register parent device!\n"); 724 return PTR_ERR(vm_cmdline_parent); 725 } 726 vm_cmdline_parent_registered = 1; 727 } 728 729 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", 730 vm_cmdline_id, 731 (unsigned long long)resources[0].start, 732 (unsigned long long)resources[0].end, 733 (int)resources[1].start); 734 735 pdev = platform_device_register_resndata(vm_cmdline_parent, 736 "virtio-mmio", vm_cmdline_id++, 737 resources, ARRAY_SIZE(resources), NULL, 0); 738 739 return PTR_ERR_OR_ZERO(pdev); 740 } 741 742 static int vm_cmdline_get_device(struct device *dev, void *data) 743 { 744 char *buffer = data; 745 unsigned int len = strlen(buffer); 746 struct platform_device *pdev = to_platform_device(dev); 747 748 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", 749 pdev->resource[0].end - pdev->resource[0].start + 1ULL, 750 (unsigned long long)pdev->resource[0].start, 751 (unsigned long long)pdev->resource[1].start, 752 pdev->id); 753 return 0; 754 } 755 756 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 757 { 758 buffer[0] = '\0'; 759 760 if (vm_cmdline_parent_registered) { 761 device_for_each_child(vm_cmdline_parent, buffer, 762 vm_cmdline_get_device); 763 } 764 765 return strlen(buffer) + 1; 766 } 767 768 static const struct kernel_param_ops vm_cmdline_param_ops = { 769 .set = vm_cmdline_set, 770 .get = vm_cmdline_get, 771 }; 772 773 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 774 775 static int vm_unregister_cmdline_device(struct device *dev, 776 void *data) 777 { 778 platform_device_unregister(to_platform_device(dev)); 779 780 return 0; 781 } 782 783 static void vm_unregister_cmdline_devices(void) 784 { 785 if (vm_cmdline_parent_registered) { 786 device_for_each_child(vm_cmdline_parent, NULL, 787 vm_unregister_cmdline_device); 788 root_device_unregister(vm_cmdline_parent); 789 vm_cmdline_parent_registered = 0; 790 } 791 } 792 793 #else 794 795 static void vm_unregister_cmdline_devices(void) 796 { 797 } 798 799 #endif 800 801 /* Platform driver */ 802 803 static const struct of_device_id virtio_mmio_match[] = { 804 { .compatible = "virtio,mmio", }, 805 {}, 806 }; 807 MODULE_DEVICE_TABLE(of, virtio_mmio_match); 808 809 #ifdef CONFIG_ACPI 810 static const struct acpi_device_id virtio_mmio_acpi_match[] = { 811 { "LNRO0005", }, 812 { } 813 }; 814 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 815 #endif 816 817 static struct platform_driver virtio_mmio_driver = { 818 .probe = virtio_mmio_probe, 819 .remove = virtio_mmio_remove, 820 .driver = { 821 .name = "virtio-mmio", 822 .of_match_table = virtio_mmio_match, 823 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 824 #ifdef CONFIG_PM_SLEEP 825 .pm = &virtio_mmio_pm_ops, 826 #endif 827 }, 828 }; 829 830 static int __init virtio_mmio_init(void) 831 { 832 return platform_driver_register(&virtio_mmio_driver); 833 } 834 835 static void __exit virtio_mmio_exit(void) 836 { 837 platform_driver_unregister(&virtio_mmio_driver); 838 vm_unregister_cmdline_devices(); 839 } 840 841 module_init(virtio_mmio_init); 842 module_exit(virtio_mmio_exit); 843 844 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 845 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 846 MODULE_LICENSE("GPL"); 847