1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2020 Intel Corporation 4 * Author: Johannes Berg <johannes@sipsolutions.net> 5 */ 6 #include <linux/module.h> 7 #include <linux/pci.h> 8 #include <linux/virtio.h> 9 #include <linux/virtio_config.h> 10 #include <linux/logic_iomem.h> 11 #include <linux/irqdomain.h> 12 #include <linux/virtio_pcidev.h> 13 #include <linux/virtio-uml.h> 14 #include <linux/delay.h> 15 #include <linux/msi.h> 16 #include <asm/unaligned.h> 17 #include <irq_kern.h> 18 19 #define MAX_DEVICES 8 20 #define MAX_MSI_VECTORS 32 21 #define CFG_SPACE_SIZE 4096 22 23 /* for MSI-X we have a 32-bit payload */ 24 #define MAX_IRQ_MSG_SIZE (sizeof(struct virtio_pcidev_msg) + sizeof(u32)) 25 #define NUM_IRQ_MSGS 10 26 27 #define HANDLE_NO_FREE(ptr) ((void *)((unsigned long)(ptr) | 1)) 28 #define HANDLE_IS_NO_FREE(ptr) ((unsigned long)(ptr) & 1) 29 30 struct um_pci_device { 31 struct virtio_device *vdev; 32 33 /* for now just standard BARs */ 34 u8 resptr[PCI_STD_NUM_BARS]; 35 36 struct virtqueue *cmd_vq, *irq_vq; 37 38 #define UM_PCI_STAT_WAITING 0 39 unsigned long status; 40 41 int irq; 42 }; 43 44 struct um_pci_device_reg { 45 struct um_pci_device *dev; 46 void __iomem *iomem; 47 }; 48 49 static struct pci_host_bridge *bridge; 50 static DEFINE_MUTEX(um_pci_mtx); 51 static struct um_pci_device_reg um_pci_devices[MAX_DEVICES]; 52 static struct fwnode_handle *um_pci_fwnode; 53 static struct irq_domain *um_pci_inner_domain; 54 static struct irq_domain *um_pci_msi_domain; 55 static unsigned long um_pci_msi_used[BITS_TO_LONGS(MAX_MSI_VECTORS)]; 56 57 #define UM_VIRT_PCI_MAXDELAY 40000 58 59 struct um_pci_message_buffer { 60 struct virtio_pcidev_msg hdr; 61 u8 data[8]; 62 }; 63 64 static struct um_pci_message_buffer __percpu *um_pci_msg_bufs; 65 66 static int um_pci_send_cmd(struct um_pci_device *dev, 67 struct virtio_pcidev_msg *cmd, 68 unsigned int cmd_size, 69 const void *extra, unsigned int extra_size, 70 void *out, unsigned int out_size) 71 { 72 struct scatterlist out_sg, extra_sg, in_sg; 73 struct scatterlist *sgs_list[] = { 74 [0] = &out_sg, 75 [1] = extra ? &extra_sg : &in_sg, 76 [2] = extra ? &in_sg : NULL, 77 }; 78 struct um_pci_message_buffer *buf; 79 int delay_count = 0; 80 int ret, len; 81 bool posted; 82 83 if (WARN_ON(cmd_size < sizeof(*cmd) || cmd_size > sizeof(*buf))) 84 return -EINVAL; 85 86 switch (cmd->op) { 87 case VIRTIO_PCIDEV_OP_CFG_WRITE: 88 case VIRTIO_PCIDEV_OP_MMIO_WRITE: 89 case VIRTIO_PCIDEV_OP_MMIO_MEMSET: 90 /* in PCI, writes are posted, so don't wait */ 91 posted = !out; 92 WARN_ON(!posted); 93 break; 94 default: 95 posted = false; 96 break; 97 } 98 99 buf = get_cpu_var(um_pci_msg_bufs); 100 memcpy(buf, cmd, cmd_size); 101 102 if (posted) { 103 u8 *ncmd = kmalloc(cmd_size + extra_size, GFP_ATOMIC); 104 105 if (ncmd) { 106 memcpy(ncmd, cmd, cmd_size); 107 if (extra) 108 memcpy(ncmd + cmd_size, extra, extra_size); 109 cmd = (void *)ncmd; 110 cmd_size += extra_size; 111 extra = NULL; 112 extra_size = 0; 113 } else { 114 /* try without allocating memory */ 115 posted = false; 116 cmd = (void *)buf; 117 } 118 } else { 119 cmd = (void *)buf; 120 } 121 122 sg_init_one(&out_sg, cmd, cmd_size); 123 if (extra) 124 sg_init_one(&extra_sg, extra, extra_size); 125 if (out) 126 sg_init_one(&in_sg, out, out_size); 127 128 /* add to internal virtio queue */ 129 ret = virtqueue_add_sgs(dev->cmd_vq, sgs_list, 130 extra ? 2 : 1, 131 out ? 1 : 0, 132 posted ? cmd : HANDLE_NO_FREE(cmd), 133 GFP_ATOMIC); 134 if (ret) 135 goto out; 136 137 if (posted) { 138 virtqueue_kick(dev->cmd_vq); 139 ret = 0; 140 goto out; 141 } 142 143 /* kick and poll for getting a response on the queue */ 144 set_bit(UM_PCI_STAT_WAITING, &dev->status); 145 virtqueue_kick(dev->cmd_vq); 146 147 while (1) { 148 void *completed = virtqueue_get_buf(dev->cmd_vq, &len); 149 150 if (completed == HANDLE_NO_FREE(cmd)) 151 break; 152 153 if (completed && !HANDLE_IS_NO_FREE(completed)) 154 kfree(completed); 155 156 if (WARN_ONCE(virtqueue_is_broken(dev->cmd_vq) || 157 ++delay_count > UM_VIRT_PCI_MAXDELAY, 158 "um virt-pci delay: %d", delay_count)) { 159 ret = -EIO; 160 break; 161 } 162 udelay(1); 163 } 164 clear_bit(UM_PCI_STAT_WAITING, &dev->status); 165 166 out: 167 put_cpu_var(um_pci_msg_bufs); 168 return ret; 169 } 170 171 static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset, 172 int size) 173 { 174 struct um_pci_device_reg *reg = priv; 175 struct um_pci_device *dev = reg->dev; 176 struct virtio_pcidev_msg hdr = { 177 .op = VIRTIO_PCIDEV_OP_CFG_READ, 178 .size = size, 179 .addr = offset, 180 }; 181 /* buf->data is maximum size - we may only use parts of it */ 182 struct um_pci_message_buffer *buf; 183 u8 *data; 184 unsigned long ret = ~0ULL; 185 186 if (!dev) 187 return ~0ULL; 188 189 buf = get_cpu_var(um_pci_msg_bufs); 190 data = buf->data; 191 192 memset(data, 0xff, sizeof(data)); 193 194 switch (size) { 195 case 1: 196 case 2: 197 case 4: 198 #ifdef CONFIG_64BIT 199 case 8: 200 #endif 201 break; 202 default: 203 WARN(1, "invalid config space read size %d\n", size); 204 goto out; 205 } 206 207 if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, 8)) 208 goto out; 209 210 switch (size) { 211 case 1: 212 ret = data[0]; 213 break; 214 case 2: 215 ret = le16_to_cpup((void *)data); 216 break; 217 case 4: 218 ret = le32_to_cpup((void *)data); 219 break; 220 #ifdef CONFIG_64BIT 221 case 8: 222 ret = le64_to_cpup((void *)data); 223 break; 224 #endif 225 default: 226 break; 227 } 228 229 out: 230 put_cpu_var(um_pci_msg_bufs); 231 return ret; 232 } 233 234 static void um_pci_cfgspace_write(void *priv, unsigned int offset, int size, 235 unsigned long val) 236 { 237 struct um_pci_device_reg *reg = priv; 238 struct um_pci_device *dev = reg->dev; 239 struct { 240 struct virtio_pcidev_msg hdr; 241 /* maximum size - we may only use parts of it */ 242 u8 data[8]; 243 } msg = { 244 .hdr = { 245 .op = VIRTIO_PCIDEV_OP_CFG_WRITE, 246 .size = size, 247 .addr = offset, 248 }, 249 }; 250 251 if (!dev) 252 return; 253 254 switch (size) { 255 case 1: 256 msg.data[0] = (u8)val; 257 break; 258 case 2: 259 put_unaligned_le16(val, (void *)msg.data); 260 break; 261 case 4: 262 put_unaligned_le32(val, (void *)msg.data); 263 break; 264 #ifdef CONFIG_64BIT 265 case 8: 266 put_unaligned_le64(val, (void *)msg.data); 267 break; 268 #endif 269 default: 270 WARN(1, "invalid config space write size %d\n", size); 271 return; 272 } 273 274 WARN_ON(um_pci_send_cmd(dev, &msg.hdr, sizeof(msg), NULL, 0, NULL, 0)); 275 } 276 277 static const struct logic_iomem_ops um_pci_device_cfgspace_ops = { 278 .read = um_pci_cfgspace_read, 279 .write = um_pci_cfgspace_write, 280 }; 281 282 static void um_pci_bar_copy_from(void *priv, void *buffer, 283 unsigned int offset, int size) 284 { 285 u8 *resptr = priv; 286 struct um_pci_device *dev = container_of(resptr - *resptr, 287 struct um_pci_device, 288 resptr[0]); 289 struct virtio_pcidev_msg hdr = { 290 .op = VIRTIO_PCIDEV_OP_MMIO_READ, 291 .bar = *resptr, 292 .size = size, 293 .addr = offset, 294 }; 295 296 memset(buffer, 0xff, size); 297 298 um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, buffer, size); 299 } 300 301 static unsigned long um_pci_bar_read(void *priv, unsigned int offset, 302 int size) 303 { 304 /* buf->data is maximum size - we may only use parts of it */ 305 struct um_pci_message_buffer *buf; 306 u8 *data; 307 unsigned long ret = ~0ULL; 308 309 buf = get_cpu_var(um_pci_msg_bufs); 310 data = buf->data; 311 312 switch (size) { 313 case 1: 314 case 2: 315 case 4: 316 #ifdef CONFIG_64BIT 317 case 8: 318 #endif 319 break; 320 default: 321 WARN(1, "invalid config space read size %d\n", size); 322 goto out; 323 } 324 325 um_pci_bar_copy_from(priv, data, offset, size); 326 327 switch (size) { 328 case 1: 329 ret = data[0]; 330 break; 331 case 2: 332 ret = le16_to_cpup((void *)data); 333 break; 334 case 4: 335 ret = le32_to_cpup((void *)data); 336 break; 337 #ifdef CONFIG_64BIT 338 case 8: 339 ret = le64_to_cpup((void *)data); 340 break; 341 #endif 342 default: 343 break; 344 } 345 346 out: 347 put_cpu_var(um_pci_msg_bufs); 348 return ret; 349 } 350 351 static void um_pci_bar_copy_to(void *priv, unsigned int offset, 352 const void *buffer, int size) 353 { 354 u8 *resptr = priv; 355 struct um_pci_device *dev = container_of(resptr - *resptr, 356 struct um_pci_device, 357 resptr[0]); 358 struct virtio_pcidev_msg hdr = { 359 .op = VIRTIO_PCIDEV_OP_MMIO_WRITE, 360 .bar = *resptr, 361 .size = size, 362 .addr = offset, 363 }; 364 365 um_pci_send_cmd(dev, &hdr, sizeof(hdr), buffer, size, NULL, 0); 366 } 367 368 static void um_pci_bar_write(void *priv, unsigned int offset, int size, 369 unsigned long val) 370 { 371 /* maximum size - we may only use parts of it */ 372 u8 data[8]; 373 374 switch (size) { 375 case 1: 376 data[0] = (u8)val; 377 break; 378 case 2: 379 put_unaligned_le16(val, (void *)data); 380 break; 381 case 4: 382 put_unaligned_le32(val, (void *)data); 383 break; 384 #ifdef CONFIG_64BIT 385 case 8: 386 put_unaligned_le64(val, (void *)data); 387 break; 388 #endif 389 default: 390 WARN(1, "invalid config space write size %d\n", size); 391 return; 392 } 393 394 um_pci_bar_copy_to(priv, offset, data, size); 395 } 396 397 static void um_pci_bar_set(void *priv, unsigned int offset, u8 value, int size) 398 { 399 u8 *resptr = priv; 400 struct um_pci_device *dev = container_of(resptr - *resptr, 401 struct um_pci_device, 402 resptr[0]); 403 struct { 404 struct virtio_pcidev_msg hdr; 405 u8 data; 406 } msg = { 407 .hdr = { 408 .op = VIRTIO_PCIDEV_OP_CFG_WRITE, 409 .bar = *resptr, 410 .size = size, 411 .addr = offset, 412 }, 413 .data = value, 414 }; 415 416 um_pci_send_cmd(dev, &msg.hdr, sizeof(msg), NULL, 0, NULL, 0); 417 } 418 419 static const struct logic_iomem_ops um_pci_device_bar_ops = { 420 .read = um_pci_bar_read, 421 .write = um_pci_bar_write, 422 .set = um_pci_bar_set, 423 .copy_from = um_pci_bar_copy_from, 424 .copy_to = um_pci_bar_copy_to, 425 }; 426 427 static void __iomem *um_pci_map_bus(struct pci_bus *bus, unsigned int devfn, 428 int where) 429 { 430 struct um_pci_device_reg *dev; 431 unsigned int busn = bus->number; 432 433 if (busn > 0) 434 return NULL; 435 436 /* not allowing functions for now ... */ 437 if (devfn % 8) 438 return NULL; 439 440 if (devfn / 8 >= ARRAY_SIZE(um_pci_devices)) 441 return NULL; 442 443 dev = &um_pci_devices[devfn / 8]; 444 if (!dev) 445 return NULL; 446 447 return (void __iomem *)((unsigned long)dev->iomem + where); 448 } 449 450 static struct pci_ops um_pci_ops = { 451 .map_bus = um_pci_map_bus, 452 .read = pci_generic_config_read, 453 .write = pci_generic_config_write, 454 }; 455 456 static void um_pci_rescan(void) 457 { 458 pci_lock_rescan_remove(); 459 pci_rescan_bus(bridge->bus); 460 pci_unlock_rescan_remove(); 461 } 462 463 static void um_pci_irq_vq_addbuf(struct virtqueue *vq, void *buf, bool kick) 464 { 465 struct scatterlist sg[1]; 466 467 sg_init_one(sg, buf, MAX_IRQ_MSG_SIZE); 468 if (virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC)) 469 kfree(buf); 470 else if (kick) 471 virtqueue_kick(vq); 472 } 473 474 static void um_pci_handle_irq_message(struct virtqueue *vq, 475 struct virtio_pcidev_msg *msg) 476 { 477 struct virtio_device *vdev = vq->vdev; 478 struct um_pci_device *dev = vdev->priv; 479 480 /* we should properly chain interrupts, but on ARCH=um we don't care */ 481 482 switch (msg->op) { 483 case VIRTIO_PCIDEV_OP_INT: 484 generic_handle_irq(dev->irq); 485 break; 486 case VIRTIO_PCIDEV_OP_MSI: 487 /* our MSI message is just the interrupt number */ 488 if (msg->size == sizeof(u32)) 489 generic_handle_irq(le32_to_cpup((void *)msg->data)); 490 else 491 generic_handle_irq(le16_to_cpup((void *)msg->data)); 492 break; 493 case VIRTIO_PCIDEV_OP_PME: 494 /* nothing to do - we already woke up due to the message */ 495 break; 496 default: 497 dev_err(&vdev->dev, "unexpected virt-pci message %d\n", msg->op); 498 break; 499 } 500 } 501 502 static void um_pci_cmd_vq_cb(struct virtqueue *vq) 503 { 504 struct virtio_device *vdev = vq->vdev; 505 struct um_pci_device *dev = vdev->priv; 506 void *cmd; 507 int len; 508 509 if (test_bit(UM_PCI_STAT_WAITING, &dev->status)) 510 return; 511 512 while ((cmd = virtqueue_get_buf(vq, &len))) { 513 if (WARN_ON(HANDLE_IS_NO_FREE(cmd))) 514 continue; 515 kfree(cmd); 516 } 517 } 518 519 static void um_pci_irq_vq_cb(struct virtqueue *vq) 520 { 521 struct virtio_pcidev_msg *msg; 522 int len; 523 524 while ((msg = virtqueue_get_buf(vq, &len))) { 525 if (len >= sizeof(*msg)) 526 um_pci_handle_irq_message(vq, msg); 527 528 /* recycle the message buffer */ 529 um_pci_irq_vq_addbuf(vq, msg, true); 530 } 531 } 532 533 static int um_pci_init_vqs(struct um_pci_device *dev) 534 { 535 struct virtqueue *vqs[2]; 536 static const char *const names[2] = { "cmd", "irq" }; 537 vq_callback_t *cbs[2] = { um_pci_cmd_vq_cb, um_pci_irq_vq_cb }; 538 int err, i; 539 540 err = virtio_find_vqs(dev->vdev, 2, vqs, cbs, names, NULL); 541 if (err) 542 return err; 543 544 dev->cmd_vq = vqs[0]; 545 dev->irq_vq = vqs[1]; 546 547 for (i = 0; i < NUM_IRQ_MSGS; i++) { 548 void *msg = kzalloc(MAX_IRQ_MSG_SIZE, GFP_KERNEL); 549 550 if (msg) 551 um_pci_irq_vq_addbuf(dev->irq_vq, msg, false); 552 } 553 554 virtqueue_kick(dev->irq_vq); 555 556 return 0; 557 } 558 559 static int um_pci_virtio_probe(struct virtio_device *vdev) 560 { 561 struct um_pci_device *dev; 562 int i, free = -1; 563 int err = -ENOSPC; 564 565 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 566 if (!dev) 567 return -ENOMEM; 568 569 dev->vdev = vdev; 570 vdev->priv = dev; 571 572 mutex_lock(&um_pci_mtx); 573 for (i = 0; i < MAX_DEVICES; i++) { 574 if (um_pci_devices[i].dev) 575 continue; 576 free = i; 577 break; 578 } 579 580 if (free < 0) 581 goto error; 582 583 err = um_pci_init_vqs(dev); 584 if (err) 585 goto error; 586 587 dev->irq = irq_alloc_desc(numa_node_id()); 588 if (dev->irq < 0) { 589 err = dev->irq; 590 goto error; 591 } 592 um_pci_devices[free].dev = dev; 593 vdev->priv = dev; 594 595 mutex_unlock(&um_pci_mtx); 596 597 device_set_wakeup_enable(&vdev->dev, true); 598 599 /* 600 * In order to do suspend-resume properly, don't allow VQs 601 * to be suspended. 602 */ 603 virtio_uml_set_no_vq_suspend(vdev, true); 604 605 um_pci_rescan(); 606 return 0; 607 error: 608 mutex_unlock(&um_pci_mtx); 609 kfree(dev); 610 return err; 611 } 612 613 static void um_pci_virtio_remove(struct virtio_device *vdev) 614 { 615 struct um_pci_device *dev = vdev->priv; 616 int i; 617 618 /* Stop all virtqueues */ 619 vdev->config->reset(vdev); 620 vdev->config->del_vqs(vdev); 621 622 device_set_wakeup_enable(&vdev->dev, false); 623 624 mutex_lock(&um_pci_mtx); 625 for (i = 0; i < MAX_DEVICES; i++) { 626 if (um_pci_devices[i].dev != dev) 627 continue; 628 um_pci_devices[i].dev = NULL; 629 irq_free_desc(dev->irq); 630 } 631 mutex_unlock(&um_pci_mtx); 632 633 um_pci_rescan(); 634 635 kfree(dev); 636 } 637 638 static struct virtio_device_id id_table[] = { 639 { CONFIG_UML_PCI_OVER_VIRTIO_DEVICE_ID, VIRTIO_DEV_ANY_ID }, 640 { 0 }, 641 }; 642 MODULE_DEVICE_TABLE(virtio, id_table); 643 644 static struct virtio_driver um_pci_virtio_driver = { 645 .driver.name = "virtio-pci", 646 .driver.owner = THIS_MODULE, 647 .id_table = id_table, 648 .probe = um_pci_virtio_probe, 649 .remove = um_pci_virtio_remove, 650 }; 651 652 static struct resource virt_cfgspace_resource = { 653 .name = "PCI config space", 654 .start = 0xf0000000 - MAX_DEVICES * CFG_SPACE_SIZE, 655 .end = 0xf0000000 - 1, 656 .flags = IORESOURCE_MEM, 657 }; 658 659 static long um_pci_map_cfgspace(unsigned long offset, size_t size, 660 const struct logic_iomem_ops **ops, 661 void **priv) 662 { 663 if (WARN_ON(size > CFG_SPACE_SIZE || offset % CFG_SPACE_SIZE)) 664 return -EINVAL; 665 666 if (offset / CFG_SPACE_SIZE < MAX_DEVICES) { 667 *ops = &um_pci_device_cfgspace_ops; 668 *priv = &um_pci_devices[offset / CFG_SPACE_SIZE]; 669 return 0; 670 } 671 672 WARN(1, "cannot map offset 0x%lx/0x%zx\n", offset, size); 673 return -ENOENT; 674 } 675 676 static const struct logic_iomem_region_ops um_pci_cfgspace_ops = { 677 .map = um_pci_map_cfgspace, 678 }; 679 680 static struct resource virt_iomem_resource = { 681 .name = "PCI iomem", 682 .start = 0xf0000000, 683 .end = 0xffffffff, 684 .flags = IORESOURCE_MEM, 685 }; 686 687 struct um_pci_map_iomem_data { 688 unsigned long offset; 689 size_t size; 690 const struct logic_iomem_ops **ops; 691 void **priv; 692 long ret; 693 }; 694 695 static int um_pci_map_iomem_walk(struct pci_dev *pdev, void *_data) 696 { 697 struct um_pci_map_iomem_data *data = _data; 698 struct um_pci_device_reg *reg = &um_pci_devices[pdev->devfn / 8]; 699 struct um_pci_device *dev; 700 int i; 701 702 if (!reg->dev) 703 return 0; 704 705 for (i = 0; i < ARRAY_SIZE(dev->resptr); i++) { 706 struct resource *r = &pdev->resource[i]; 707 708 if ((r->flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) 709 continue; 710 711 /* 712 * must be the whole or part of the resource, 713 * not allowed to only overlap 714 */ 715 if (data->offset < r->start || data->offset > r->end) 716 continue; 717 if (data->offset + data->size - 1 > r->end) 718 continue; 719 720 dev = reg->dev; 721 *data->ops = &um_pci_device_bar_ops; 722 dev->resptr[i] = i; 723 *data->priv = &dev->resptr[i]; 724 data->ret = data->offset - r->start; 725 726 /* no need to continue */ 727 return 1; 728 } 729 730 return 0; 731 } 732 733 static long um_pci_map_iomem(unsigned long offset, size_t size, 734 const struct logic_iomem_ops **ops, 735 void **priv) 736 { 737 struct um_pci_map_iomem_data data = { 738 /* we want the full address here */ 739 .offset = offset + virt_iomem_resource.start, 740 .size = size, 741 .ops = ops, 742 .priv = priv, 743 .ret = -ENOENT, 744 }; 745 746 pci_walk_bus(bridge->bus, um_pci_map_iomem_walk, &data); 747 return data.ret; 748 } 749 750 static const struct logic_iomem_region_ops um_pci_iomem_ops = { 751 .map = um_pci_map_iomem, 752 }; 753 754 static void um_pci_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 755 { 756 /* 757 * This is a very low address and not actually valid 'physical' memory 758 * in UML, so we can simply map MSI(-X) vectors to there, it cannot be 759 * legitimately written to by the device in any other way. 760 * We use the (virtual) IRQ number here as the message to simplify the 761 * code that receives the message, where for now we simply trust the 762 * device to send the correct message. 763 */ 764 msg->address_hi = 0; 765 msg->address_lo = 0xa0000; 766 msg->data = data->irq; 767 } 768 769 static struct irq_chip um_pci_msi_bottom_irq_chip = { 770 .name = "UM virtio MSI", 771 .irq_compose_msi_msg = um_pci_compose_msi_msg, 772 }; 773 774 static int um_pci_inner_domain_alloc(struct irq_domain *domain, 775 unsigned int virq, unsigned int nr_irqs, 776 void *args) 777 { 778 unsigned long bit; 779 780 WARN_ON(nr_irqs != 1); 781 782 mutex_lock(&um_pci_mtx); 783 bit = find_first_zero_bit(um_pci_msi_used, MAX_MSI_VECTORS); 784 if (bit >= MAX_MSI_VECTORS) { 785 mutex_unlock(&um_pci_mtx); 786 return -ENOSPC; 787 } 788 789 set_bit(bit, um_pci_msi_used); 790 mutex_unlock(&um_pci_mtx); 791 792 irq_domain_set_info(domain, virq, bit, &um_pci_msi_bottom_irq_chip, 793 domain->host_data, handle_simple_irq, 794 NULL, NULL); 795 796 return 0; 797 } 798 799 static void um_pci_inner_domain_free(struct irq_domain *domain, 800 unsigned int virq, unsigned int nr_irqs) 801 { 802 struct irq_data *d = irq_domain_get_irq_data(domain, virq); 803 804 mutex_lock(&um_pci_mtx); 805 806 if (!test_bit(d->hwirq, um_pci_msi_used)) 807 pr_err("trying to free unused MSI#%lu\n", d->hwirq); 808 else 809 __clear_bit(d->hwirq, um_pci_msi_used); 810 811 mutex_unlock(&um_pci_mtx); 812 } 813 814 static const struct irq_domain_ops um_pci_inner_domain_ops = { 815 .alloc = um_pci_inner_domain_alloc, 816 .free = um_pci_inner_domain_free, 817 }; 818 819 static struct irq_chip um_pci_msi_irq_chip = { 820 .name = "UM virtio PCIe MSI", 821 .irq_mask = pci_msi_mask_irq, 822 .irq_unmask = pci_msi_unmask_irq, 823 }; 824 825 static struct msi_domain_info um_pci_msi_domain_info = { 826 .flags = MSI_FLAG_USE_DEF_DOM_OPS | 827 MSI_FLAG_USE_DEF_CHIP_OPS | 828 MSI_FLAG_PCI_MSIX, 829 .chip = &um_pci_msi_irq_chip, 830 }; 831 832 static struct resource busn_resource = { 833 .name = "PCI busn", 834 .start = 0, 835 .end = 0, 836 .flags = IORESOURCE_BUS, 837 }; 838 839 static int um_pci_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin) 840 { 841 struct um_pci_device_reg *reg = &um_pci_devices[pdev->devfn / 8]; 842 843 if (WARN_ON(!reg->dev)) 844 return -EINVAL; 845 846 /* Yes, we map all pins to the same IRQ ... doesn't matter for now. */ 847 return reg->dev->irq; 848 } 849 850 void *pci_root_bus_fwnode(struct pci_bus *bus) 851 { 852 return um_pci_fwnode; 853 } 854 855 static int um_pci_init(void) 856 { 857 int err, i; 858 859 WARN_ON(logic_iomem_add_region(&virt_cfgspace_resource, 860 &um_pci_cfgspace_ops)); 861 WARN_ON(logic_iomem_add_region(&virt_iomem_resource, 862 &um_pci_iomem_ops)); 863 864 if (WARN(CONFIG_UML_PCI_OVER_VIRTIO_DEVICE_ID < 0, 865 "No virtio device ID configured for PCI - no PCI support\n")) 866 return 0; 867 868 um_pci_msg_bufs = alloc_percpu(struct um_pci_message_buffer); 869 if (!um_pci_msg_bufs) 870 return -ENOMEM; 871 872 bridge = pci_alloc_host_bridge(0); 873 if (!bridge) { 874 err = -ENOMEM; 875 goto free; 876 } 877 878 um_pci_fwnode = irq_domain_alloc_named_fwnode("um-pci"); 879 if (!um_pci_fwnode) { 880 err = -ENOMEM; 881 goto free; 882 } 883 884 um_pci_inner_domain = __irq_domain_add(um_pci_fwnode, MAX_MSI_VECTORS, 885 MAX_MSI_VECTORS, 0, 886 &um_pci_inner_domain_ops, NULL); 887 if (!um_pci_inner_domain) { 888 err = -ENOMEM; 889 goto free; 890 } 891 892 um_pci_msi_domain = pci_msi_create_irq_domain(um_pci_fwnode, 893 &um_pci_msi_domain_info, 894 um_pci_inner_domain); 895 if (!um_pci_msi_domain) { 896 err = -ENOMEM; 897 goto free; 898 } 899 900 pci_add_resource(&bridge->windows, &virt_iomem_resource); 901 pci_add_resource(&bridge->windows, &busn_resource); 902 bridge->ops = &um_pci_ops; 903 bridge->map_irq = um_pci_map_irq; 904 905 for (i = 0; i < MAX_DEVICES; i++) { 906 resource_size_t start; 907 908 start = virt_cfgspace_resource.start + i * CFG_SPACE_SIZE; 909 um_pci_devices[i].iomem = ioremap(start, CFG_SPACE_SIZE); 910 if (WARN(!um_pci_devices[i].iomem, "failed to map %d\n", i)) { 911 err = -ENOMEM; 912 goto free; 913 } 914 } 915 916 err = pci_host_probe(bridge); 917 if (err) 918 goto free; 919 920 err = register_virtio_driver(&um_pci_virtio_driver); 921 if (err) 922 goto free; 923 return 0; 924 free: 925 if (um_pci_inner_domain) 926 irq_domain_remove(um_pci_inner_domain); 927 if (um_pci_fwnode) 928 irq_domain_free_fwnode(um_pci_fwnode); 929 if (bridge) { 930 pci_free_resource_list(&bridge->windows); 931 pci_free_host_bridge(bridge); 932 } 933 free_percpu(um_pci_msg_bufs); 934 return err; 935 } 936 module_init(um_pci_init); 937 938 static void um_pci_exit(void) 939 { 940 unregister_virtio_driver(&um_pci_virtio_driver); 941 irq_domain_remove(um_pci_msi_domain); 942 irq_domain_remove(um_pci_inner_domain); 943 pci_free_resource_list(&bridge->windows); 944 pci_free_host_bridge(bridge); 945 free_percpu(um_pci_msg_bufs); 946 } 947 module_exit(um_pci_exit); 948