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 84struct 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 96struct 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 108static 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 123static 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 is 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 148static void vm_get(struct virtio_device *vdev, unsigned offset, 149 void *buf, unsigned 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 190static void vm_set(struct virtio_device *vdev, unsigned offset, 191 const void *buf, unsigned 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 233static 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 243static 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 250static 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 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS); 258} 259 260static void vm_reset(struct virtio_device *vdev) 261{ 262 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 263 264 /* 0 status means a reset. */ 265 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS); 266} 267 268 269 270/* Transport interface */ 271 272/* the notify function used when creating a virt queue */ 273static bool vm_notify(struct virtqueue *vq) 274{ 275 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 276 277 /* We write the queue's selector into the notification register to 278 * signal the other end */ 279 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); 280 return true; 281} 282 283/* Notify all virtqueues on an interrupt. */ 284static irqreturn_t vm_interrupt(int irq, void *opaque) 285{ 286 struct virtio_mmio_device *vm_dev = opaque; 287 struct virtio_mmio_vq_info *info; 288 unsigned long status; 289 unsigned long flags; 290 irqreturn_t ret = IRQ_NONE; 291 292 /* Read and acknowledge interrupts */ 293 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); 294 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); 295 296 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { 297 virtio_config_changed(&vm_dev->vdev); 298 ret = IRQ_HANDLED; 299 } 300 301 if (likely(status & VIRTIO_MMIO_INT_VRING)) { 302 spin_lock_irqsave(&vm_dev->lock, flags); 303 list_for_each_entry(info, &vm_dev->virtqueues, node) 304 ret |= vring_interrupt(irq, info->vq); 305 spin_unlock_irqrestore(&vm_dev->lock, flags); 306 } 307 308 return ret; 309} 310 311 312 313static void vm_del_vq(struct virtqueue *vq) 314{ 315 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); 316 struct virtio_mmio_vq_info *info = vq->priv; 317 unsigned long flags; 318 unsigned int index = vq->index; 319 320 spin_lock_irqsave(&vm_dev->lock, flags); 321 list_del(&info->node); 322 spin_unlock_irqrestore(&vm_dev->lock, flags); 323 324 /* Select and deactivate the queue */ 325 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 326 if (vm_dev->version == 1) { 327 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 328 } else { 329 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 330 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 331 } 332 333 vring_del_virtqueue(vq); 334 335 kfree(info); 336} 337 338static 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; 342 343 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 344 vm_del_vq(vq); 345 346 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); 347} 348 349static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, 350 void (*callback)(struct virtqueue *vq), 351 const char *name, bool ctx) 352{ 353 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 354 struct virtio_mmio_vq_info *info; 355 struct virtqueue *vq; 356 unsigned long flags; 357 unsigned int num; 358 int err; 359 360 if (!name) 361 return NULL; 362 363 /* Select the queue we're interested in */ 364 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); 365 366 /* Queue shouldn't already be set up. */ 367 if (readl(vm_dev->base + (vm_dev->version == 1 ? 368 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) { 369 err = -ENOENT; 370 goto error_available; 371 } 372 373 /* Allocate and fill out our active queue description */ 374 info = kmalloc(sizeof(*info), GFP_KERNEL); 375 if (!info) { 376 err = -ENOMEM; 377 goto error_kmalloc; 378 } 379 380 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); 381 if (num == 0) { 382 err = -ENOENT; 383 goto error_new_virtqueue; 384 } 385 386 /* Create the vring */ 387 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, 388 true, true, ctx, vm_notify, callback, name); 389 if (!vq) { 390 err = -ENOMEM; 391 goto error_new_virtqueue; 392 } 393 394 /* Activate the queue */ 395 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); 396 if (vm_dev->version == 1) { 397 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; 398 399 /* 400 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something 401 * that doesn't fit in 32bit, fail the setup rather than 402 * pretending to be successful. 403 */ 404 if (q_pfn >> 32) { 405 dev_err(&vdev->dev, 406 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", 407 0x1ULL << (32 + PAGE_SHIFT - 30)); 408 err = -E2BIG; 409 goto error_bad_pfn; 410 } 411 412 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); 413 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 414 } else { 415 u64 addr; 416 417 addr = virtqueue_get_desc_addr(vq); 418 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); 419 writel((u32)(addr >> 32), 420 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); 421 422 addr = virtqueue_get_avail_addr(vq); 423 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); 424 writel((u32)(addr >> 32), 425 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); 426 427 addr = virtqueue_get_used_addr(vq); 428 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); 429 writel((u32)(addr >> 32), 430 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); 431 432 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 433 } 434 435 vq->priv = info; 436 info->vq = vq; 437 438 spin_lock_irqsave(&vm_dev->lock, flags); 439 list_add(&info->node, &vm_dev->virtqueues); 440 spin_unlock_irqrestore(&vm_dev->lock, flags); 441 442 return vq; 443 444error_bad_pfn: 445 vring_del_virtqueue(vq); 446error_new_virtqueue: 447 if (vm_dev->version == 1) { 448 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); 449 } else { 450 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY); 451 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); 452 } 453 kfree(info); 454error_kmalloc: 455error_available: 456 return ERR_PTR(err); 457} 458 459static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs, 460 struct virtqueue *vqs[], 461 vq_callback_t *callbacks[], 462 const char * const names[], 463 const bool *ctx, 464 struct irq_affinity *desc) 465{ 466 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 467 int irq = platform_get_irq(vm_dev->pdev, 0); 468 int i, err, queue_idx = 0; 469 470 if (irq < 0) 471 return irq; 472 473 err = request_irq(irq, vm_interrupt, IRQF_SHARED, 474 dev_name(&vdev->dev), vm_dev); 475 if (err) 476 return err; 477 478 for (i = 0; i < nvqs; ++i) { 479 if (!names[i]) { 480 vqs[i] = NULL; 481 continue; 482 } 483 484 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i], 485 ctx ? ctx[i] : false); 486 if (IS_ERR(vqs[i])) { 487 vm_del_vqs(vdev); 488 return PTR_ERR(vqs[i]); 489 } 490 } 491 492 return 0; 493} 494 495static const char *vm_bus_name(struct virtio_device *vdev) 496{ 497 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 498 499 return vm_dev->pdev->name; 500} 501 502static bool vm_get_shm_region(struct virtio_device *vdev, 503 struct virtio_shm_region *region, u8 id) 504{ 505 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 506 u64 len, addr; 507 508 /* Select the region we're interested in */ 509 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); 510 511 /* Read the region size */ 512 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); 513 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; 514 515 region->len = len; 516 517 /* Check if region length is -1. If that's the case, the shared memory 518 * region does not exist and there is no need to proceed further. 519 */ 520 if (len == ~(u64)0) 521 return false; 522 523 /* Read the region base address */ 524 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); 525 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; 526 527 region->addr = addr; 528 529 return true; 530} 531 532static const struct virtio_config_ops virtio_mmio_config_ops = { 533 .get = vm_get, 534 .set = vm_set, 535 .generation = vm_generation, 536 .get_status = vm_get_status, 537 .set_status = vm_set_status, 538 .reset = vm_reset, 539 .find_vqs = vm_find_vqs, 540 .del_vqs = vm_del_vqs, 541 .get_features = vm_get_features, 542 .finalize_features = vm_finalize_features, 543 .bus_name = vm_bus_name, 544 .get_shm_region = vm_get_shm_region, 545}; 546 547#ifdef CONFIG_PM_SLEEP 548static int virtio_mmio_freeze(struct device *dev) 549{ 550 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 551 552 return virtio_device_freeze(&vm_dev->vdev); 553} 554 555static int virtio_mmio_restore(struct device *dev) 556{ 557 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); 558 559 if (vm_dev->version == 1) 560 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 561 562 return virtio_device_restore(&vm_dev->vdev); 563} 564 565static const struct dev_pm_ops virtio_mmio_pm_ops = { 566 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) 567}; 568#endif 569 570static void virtio_mmio_release_dev(struct device *_d) 571{ 572 struct virtio_device *vdev = 573 container_of(_d, struct virtio_device, dev); 574 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 575 576 kfree(vm_dev); 577} 578 579/* Platform device */ 580 581static int virtio_mmio_probe(struct platform_device *pdev) 582{ 583 struct virtio_mmio_device *vm_dev; 584 unsigned long magic; 585 int rc; 586 587 vm_dev = kzalloc(sizeof(*vm_dev), GFP_KERNEL); 588 if (!vm_dev) 589 return -ENOMEM; 590 591 vm_dev->vdev.dev.parent = &pdev->dev; 592 vm_dev->vdev.dev.release = virtio_mmio_release_dev; 593 vm_dev->vdev.config = &virtio_mmio_config_ops; 594 vm_dev->pdev = pdev; 595 INIT_LIST_HEAD(&vm_dev->virtqueues); 596 spin_lock_init(&vm_dev->lock); 597 598 vm_dev->base = devm_platform_ioremap_resource(pdev, 0); 599 if (IS_ERR(vm_dev->base)) { 600 rc = PTR_ERR(vm_dev->base); 601 goto free_vm_dev; 602 } 603 604 /* Check magic value */ 605 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); 606 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { 607 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); 608 rc = -ENODEV; 609 goto free_vm_dev; 610 } 611 612 /* Check device version */ 613 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION); 614 if (vm_dev->version < 1 || vm_dev->version > 2) { 615 dev_err(&pdev->dev, "Version %ld not supported!\n", 616 vm_dev->version); 617 rc = -ENXIO; 618 goto free_vm_dev; 619 } 620 621 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID); 622 if (vm_dev->vdev.id.device == 0) { 623 /* 624 * virtio-mmio device with an ID 0 is a (dummy) placeholder 625 * with no function. End probing now with no error reported. 626 */ 627 rc = -ENODEV; 628 goto free_vm_dev; 629 } 630 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID); 631 632 if (vm_dev->version == 1) { 633 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); 634 635 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); 636 /* 637 * In the legacy case, ensure our coherently-allocated virtio 638 * ring will be at an address expressable as a 32-bit PFN. 639 */ 640 if (!rc) 641 dma_set_coherent_mask(&pdev->dev, 642 DMA_BIT_MASK(32 + PAGE_SHIFT)); 643 } else { 644 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); 645 } 646 if (rc) 647 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 648 if (rc) 649 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); 650 651 platform_set_drvdata(pdev, vm_dev); 652 653 rc = register_virtio_device(&vm_dev->vdev); 654 if (rc) 655 put_device(&vm_dev->vdev.dev); 656 657 return rc; 658 659free_vm_dev: 660 kfree(vm_dev); 661 return rc; 662} 663 664static int virtio_mmio_remove(struct platform_device *pdev) 665{ 666 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); 667 unregister_virtio_device(&vm_dev->vdev); 668 669 return 0; 670} 671 672 673 674/* Devices list parameter */ 675 676#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) 677 678static struct device vm_cmdline_parent = { 679 .init_name = "virtio-mmio-cmdline", 680}; 681 682static int vm_cmdline_parent_registered; 683static int vm_cmdline_id; 684 685static int vm_cmdline_set(const char *device, 686 const struct kernel_param *kp) 687{ 688 int err; 689 struct resource resources[2] = {}; 690 char *str; 691 long long int base, size; 692 unsigned int irq; 693 int processed, consumed = 0; 694 struct platform_device *pdev; 695 696 /* Consume "size" part of the command line parameter */ 697 size = memparse(device, &str); 698 699 /* Get "@<base>:<irq>[:<id>]" chunks */ 700 processed = sscanf(str, "@%lli:%u%n:%d%n", 701 &base, &irq, &consumed, 702 &vm_cmdline_id, &consumed); 703 704 /* 705 * sscanf() must process at least 2 chunks; also there 706 * must be no extra characters after the last chunk, so 707 * str[consumed] must be '\0' 708 */ 709 if (processed < 2 || str[consumed] || irq == 0) 710 return -EINVAL; 711 712 resources[0].flags = IORESOURCE_MEM; 713 resources[0].start = base; 714 resources[0].end = base + size - 1; 715 716 resources[1].flags = IORESOURCE_IRQ; 717 resources[1].start = resources[1].end = irq; 718 719 if (!vm_cmdline_parent_registered) { 720 err = device_register(&vm_cmdline_parent); 721 if (err) { 722 put_device(&vm_cmdline_parent); 723 pr_err("Failed to register parent device!\n"); 724 return err; 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 742static 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 756static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) 757{ 758 buffer[0] = '\0'; 759 device_for_each_child(&vm_cmdline_parent, buffer, 760 vm_cmdline_get_device); 761 return strlen(buffer) + 1; 762} 763 764static const struct kernel_param_ops vm_cmdline_param_ops = { 765 .set = vm_cmdline_set, 766 .get = vm_cmdline_get, 767}; 768 769device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); 770 771static int vm_unregister_cmdline_device(struct device *dev, 772 void *data) 773{ 774 platform_device_unregister(to_platform_device(dev)); 775 776 return 0; 777} 778 779static void vm_unregister_cmdline_devices(void) 780{ 781 if (vm_cmdline_parent_registered) { 782 device_for_each_child(&vm_cmdline_parent, NULL, 783 vm_unregister_cmdline_device); 784 device_unregister(&vm_cmdline_parent); 785 vm_cmdline_parent_registered = 0; 786 } 787} 788 789#else 790 791static void vm_unregister_cmdline_devices(void) 792{ 793} 794 795#endif 796 797/* Platform driver */ 798 799static const struct of_device_id virtio_mmio_match[] = { 800 { .compatible = "virtio,mmio", }, 801 {}, 802}; 803MODULE_DEVICE_TABLE(of, virtio_mmio_match); 804 805#ifdef CONFIG_ACPI 806static const struct acpi_device_id virtio_mmio_acpi_match[] = { 807 { "LNRO0005", }, 808 { } 809}; 810MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); 811#endif 812 813static struct platform_driver virtio_mmio_driver = { 814 .probe = virtio_mmio_probe, 815 .remove = virtio_mmio_remove, 816 .driver = { 817 .name = "virtio-mmio", 818 .of_match_table = virtio_mmio_match, 819 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), 820#ifdef CONFIG_PM_SLEEP 821 .pm = &virtio_mmio_pm_ops, 822#endif 823 }, 824}; 825 826static int __init virtio_mmio_init(void) 827{ 828 return platform_driver_register(&virtio_mmio_driver); 829} 830 831static void __exit virtio_mmio_exit(void) 832{ 833 platform_driver_unregister(&virtio_mmio_driver); 834 vm_unregister_cmdline_devices(); 835} 836 837module_init(virtio_mmio_init); 838module_exit(virtio_mmio_exit); 839 840MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 841MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices"); 842MODULE_LICENSE("GPL"); 843