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/of_platform.h> 12 #include <linux/irqdomain.h> 13 #include <linux/virtio_pcidev.h> 14 #include <linux/virtio-uml.h> 15 #include <linux/delay.h> 16 #include <linux/msi.h> 17 #include <asm/unaligned.h> 18 #include <irq_kern.h> 19 20 #define MAX_DEVICES 8 21 #define MAX_MSI_VECTORS 32 22 #define CFG_SPACE_SIZE 4096 23 24 /* for MSI-X we have a 32-bit payload */ 25 #define MAX_IRQ_MSG_SIZE (sizeof(struct virtio_pcidev_msg) + sizeof(u32)) 26 #define NUM_IRQ_MSGS 10 27 28 #define HANDLE_NO_FREE(ptr) ((void *)((unsigned long)(ptr) | 1)) 29 #define HANDLE_IS_NO_FREE(ptr) ((unsigned long)(ptr) & 1) 30 31 struct um_pci_device { 32 struct virtio_device *vdev; 33 34 /* for now just standard BARs */ 35 u8 resptr[PCI_STD_NUM_BARS]; 36 37 struct virtqueue *cmd_vq, *irq_vq; 38 39 #define UM_PCI_STAT_WAITING 0 40 unsigned long status; 41 42 int irq; 43 44 bool platform; 45 }; 46 47 struct um_pci_device_reg { 48 struct um_pci_device *dev; 49 void __iomem *iomem; 50 }; 51 52 static struct pci_host_bridge *bridge; 53 static DEFINE_MUTEX(um_pci_mtx); 54 static struct um_pci_device *um_pci_platform_device; 55 static struct um_pci_device_reg um_pci_devices[MAX_DEVICES]; 56 static struct fwnode_handle *um_pci_fwnode; 57 static struct irq_domain *um_pci_inner_domain; 58 static struct irq_domain *um_pci_msi_domain; 59 static unsigned long um_pci_msi_used[BITS_TO_LONGS(MAX_MSI_VECTORS)]; 60 61 static unsigned int um_pci_max_delay_us = 40000; 62 module_param_named(max_delay_us, um_pci_max_delay_us, uint, 0644); 63 64 struct um_pci_message_buffer { 65 struct virtio_pcidev_msg hdr; 66 u8 data[8]; 67 }; 68 69 static struct um_pci_message_buffer __percpu *um_pci_msg_bufs; 70 71 static int um_pci_send_cmd(struct um_pci_device *dev, 72 struct virtio_pcidev_msg *cmd, 73 unsigned int cmd_size, 74 const void *extra, unsigned int extra_size, 75 void *out, unsigned int out_size) 76 { 77 struct scatterlist out_sg, extra_sg, in_sg; 78 struct scatterlist *sgs_list[] = { 79 [0] = &out_sg, 80 [1] = extra ? &extra_sg : &in_sg, 81 [2] = extra ? &in_sg : NULL, 82 }; 83 struct um_pci_message_buffer *buf; 84 int delay_count = 0; 85 int ret, len; 86 bool posted; 87 88 if (WARN_ON(cmd_size < sizeof(*cmd) || cmd_size > sizeof(*buf))) 89 return -EINVAL; 90 91 switch (cmd->op) { 92 case VIRTIO_PCIDEV_OP_CFG_WRITE: 93 case VIRTIO_PCIDEV_OP_MMIO_WRITE: 94 case VIRTIO_PCIDEV_OP_MMIO_MEMSET: 95 /* in PCI, writes are posted, so don't wait */ 96 posted = !out; 97 WARN_ON(!posted); 98 break; 99 default: 100 posted = false; 101 break; 102 } 103 104 buf = get_cpu_var(um_pci_msg_bufs); 105 if (buf) 106 memcpy(buf, cmd, cmd_size); 107 108 if (posted) { 109 u8 *ncmd = kmalloc(cmd_size + extra_size, GFP_ATOMIC); 110 111 if (ncmd) { 112 memcpy(ncmd, cmd, cmd_size); 113 if (extra) 114 memcpy(ncmd + cmd_size, extra, extra_size); 115 cmd = (void *)ncmd; 116 cmd_size += extra_size; 117 extra = NULL; 118 extra_size = 0; 119 } else { 120 /* try without allocating memory */ 121 posted = false; 122 cmd = (void *)buf; 123 } 124 } else { 125 cmd = (void *)buf; 126 } 127 128 sg_init_one(&out_sg, cmd, cmd_size); 129 if (extra) 130 sg_init_one(&extra_sg, extra, extra_size); 131 if (out) 132 sg_init_one(&in_sg, out, out_size); 133 134 /* add to internal virtio queue */ 135 ret = virtqueue_add_sgs(dev->cmd_vq, sgs_list, 136 extra ? 2 : 1, 137 out ? 1 : 0, 138 posted ? cmd : HANDLE_NO_FREE(cmd), 139 GFP_ATOMIC); 140 if (ret) { 141 if (posted) 142 kfree(cmd); 143 goto out; 144 } 145 146 if (posted) { 147 virtqueue_kick(dev->cmd_vq); 148 ret = 0; 149 goto out; 150 } 151 152 /* kick and poll for getting a response on the queue */ 153 set_bit(UM_PCI_STAT_WAITING, &dev->status); 154 virtqueue_kick(dev->cmd_vq); 155 156 while (1) { 157 void *completed = virtqueue_get_buf(dev->cmd_vq, &len); 158 159 if (completed == HANDLE_NO_FREE(cmd)) 160 break; 161 162 if (completed && !HANDLE_IS_NO_FREE(completed)) 163 kfree(completed); 164 165 if (WARN_ONCE(virtqueue_is_broken(dev->cmd_vq) || 166 ++delay_count > um_pci_max_delay_us, 167 "um virt-pci delay: %d", delay_count)) { 168 ret = -EIO; 169 break; 170 } 171 udelay(1); 172 } 173 clear_bit(UM_PCI_STAT_WAITING, &dev->status); 174 175 out: 176 put_cpu_var(um_pci_msg_bufs); 177 return ret; 178 } 179 180 static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset, 181 int size) 182 { 183 struct um_pci_device_reg *reg = priv; 184 struct um_pci_device *dev = reg->dev; 185 struct virtio_pcidev_msg hdr = { 186 .op = VIRTIO_PCIDEV_OP_CFG_READ, 187 .size = size, 188 .addr = offset, 189 }; 190 /* buf->data is maximum size - we may only use parts of it */ 191 struct um_pci_message_buffer *buf; 192 u8 *data; 193 unsigned long ret = ULONG_MAX; 194 size_t bytes = sizeof(buf->data); 195 196 if (!dev) 197 return ULONG_MAX; 198 199 buf = get_cpu_var(um_pci_msg_bufs); 200 data = buf->data; 201 202 if (buf) 203 memset(data, 0xff, bytes); 204 205 switch (size) { 206 case 1: 207 case 2: 208 case 4: 209 #ifdef CONFIG_64BIT 210 case 8: 211 #endif 212 break; 213 default: 214 WARN(1, "invalid config space read size %d\n", size); 215 goto out; 216 } 217 218 if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, bytes)) 219 goto out; 220 221 switch (size) { 222 case 1: 223 ret = data[0]; 224 break; 225 case 2: 226 ret = le16_to_cpup((void *)data); 227 break; 228 case 4: 229 ret = le32_to_cpup((void *)data); 230 break; 231 #ifdef CONFIG_64BIT 232 case 8: 233 ret = le64_to_cpup((void *)data); 234 break; 235 #endif 236 default: 237 break; 238 } 239 240 out: 241 put_cpu_var(um_pci_msg_bufs); 242 return ret; 243 } 244 245 static void um_pci_cfgspace_write(void *priv, unsigned int offset, int size, 246 unsigned long val) 247 { 248 struct um_pci_device_reg *reg = priv; 249 struct um_pci_device *dev = reg->dev; 250 struct { 251 struct virtio_pcidev_msg hdr; 252 /* maximum size - we may only use parts of it */ 253 u8 data[8]; 254 } msg = { 255 .hdr = { 256 .op = VIRTIO_PCIDEV_OP_CFG_WRITE, 257 .size = size, 258 .addr = offset, 259 }, 260 }; 261 262 if (!dev) 263 return; 264 265 switch (size) { 266 case 1: 267 msg.data[0] = (u8)val; 268 break; 269 case 2: 270 put_unaligned_le16(val, (void *)msg.data); 271 break; 272 case 4: 273 put_unaligned_le32(val, (void *)msg.data); 274 break; 275 #ifdef CONFIG_64BIT 276 case 8: 277 put_unaligned_le64(val, (void *)msg.data); 278 break; 279 #endif 280 default: 281 WARN(1, "invalid config space write size %d\n", size); 282 return; 283 } 284 285 WARN_ON(um_pci_send_cmd(dev, &msg.hdr, sizeof(msg), NULL, 0, NULL, 0)); 286 } 287 288 static const struct logic_iomem_ops um_pci_device_cfgspace_ops = { 289 .read = um_pci_cfgspace_read, 290 .write = um_pci_cfgspace_write, 291 }; 292 293 static void um_pci_bar_copy_from(void *priv, void *buffer, 294 unsigned int offset, int size) 295 { 296 u8 *resptr = priv; 297 struct um_pci_device *dev = container_of(resptr - *resptr, 298 struct um_pci_device, 299 resptr[0]); 300 struct virtio_pcidev_msg hdr = { 301 .op = VIRTIO_PCIDEV_OP_MMIO_READ, 302 .bar = *resptr, 303 .size = size, 304 .addr = offset, 305 }; 306 307 memset(buffer, 0xff, size); 308 309 um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, buffer, size); 310 } 311 312 static unsigned long um_pci_bar_read(void *priv, unsigned int offset, 313 int size) 314 { 315 /* buf->data is maximum size - we may only use parts of it */ 316 struct um_pci_message_buffer *buf; 317 u8 *data; 318 unsigned long ret = ULONG_MAX; 319 320 buf = get_cpu_var(um_pci_msg_bufs); 321 data = buf->data; 322 323 switch (size) { 324 case 1: 325 case 2: 326 case 4: 327 #ifdef CONFIG_64BIT 328 case 8: 329 #endif 330 break; 331 default: 332 WARN(1, "invalid config space read size %d\n", size); 333 goto out; 334 } 335 336 um_pci_bar_copy_from(priv, data, offset, size); 337 338 switch (size) { 339 case 1: 340 ret = data[0]; 341 break; 342 case 2: 343 ret = le16_to_cpup((void *)data); 344 break; 345 case 4: 346 ret = le32_to_cpup((void *)data); 347 break; 348 #ifdef CONFIG_64BIT 349 case 8: 350 ret = le64_to_cpup((void *)data); 351 break; 352 #endif 353 default: 354 break; 355 } 356 357 out: 358 put_cpu_var(um_pci_msg_bufs); 359 return ret; 360 } 361 362 static void um_pci_bar_copy_to(void *priv, unsigned int offset, 363 const void *buffer, int size) 364 { 365 u8 *resptr = priv; 366 struct um_pci_device *dev = container_of(resptr - *resptr, 367 struct um_pci_device, 368 resptr[0]); 369 struct virtio_pcidev_msg hdr = { 370 .op = VIRTIO_PCIDEV_OP_MMIO_WRITE, 371 .bar = *resptr, 372 .size = size, 373 .addr = offset, 374 }; 375 376 um_pci_send_cmd(dev, &hdr, sizeof(hdr), buffer, size, NULL, 0); 377 } 378 379 static void um_pci_bar_write(void *priv, unsigned int offset, int size, 380 unsigned long val) 381 { 382 /* maximum size - we may only use parts of it */ 383 u8 data[8]; 384 385 switch (size) { 386 case 1: 387 data[0] = (u8)val; 388 break; 389 case 2: 390 put_unaligned_le16(val, (void *)data); 391 break; 392 case 4: 393 put_unaligned_le32(val, (void *)data); 394 break; 395 #ifdef CONFIG_64BIT 396 case 8: 397 put_unaligned_le64(val, (void *)data); 398 break; 399 #endif 400 default: 401 WARN(1, "invalid config space write size %d\n", size); 402 return; 403 } 404 405 um_pci_bar_copy_to(priv, offset, data, size); 406 } 407 408 static void um_pci_bar_set(void *priv, unsigned int offset, u8 value, int size) 409 { 410 u8 *resptr = priv; 411 struct um_pci_device *dev = container_of(resptr - *resptr, 412 struct um_pci_device, 413 resptr[0]); 414 struct { 415 struct virtio_pcidev_msg hdr; 416 u8 data; 417 } msg = { 418 .hdr = { 419 .op = VIRTIO_PCIDEV_OP_CFG_WRITE, 420 .bar = *resptr, 421 .size = size, 422 .addr = offset, 423 }, 424 .data = value, 425 }; 426 427 um_pci_send_cmd(dev, &msg.hdr, sizeof(msg), NULL, 0, NULL, 0); 428 } 429 430 static const struct logic_iomem_ops um_pci_device_bar_ops = { 431 .read = um_pci_bar_read, 432 .write = um_pci_bar_write, 433 .set = um_pci_bar_set, 434 .copy_from = um_pci_bar_copy_from, 435 .copy_to = um_pci_bar_copy_to, 436 }; 437 438 static void __iomem *um_pci_map_bus(struct pci_bus *bus, unsigned int devfn, 439 int where) 440 { 441 struct um_pci_device_reg *dev; 442 unsigned int busn = bus->number; 443 444 if (busn > 0) 445 return NULL; 446 447 /* not allowing functions for now ... */ 448 if (devfn % 8) 449 return NULL; 450 451 if (devfn / 8 >= ARRAY_SIZE(um_pci_devices)) 452 return NULL; 453 454 dev = &um_pci_devices[devfn / 8]; 455 if (!dev) 456 return NULL; 457 458 return (void __iomem *)((unsigned long)dev->iomem + where); 459 } 460 461 static struct pci_ops um_pci_ops = { 462 .map_bus = um_pci_map_bus, 463 .read = pci_generic_config_read, 464 .write = pci_generic_config_write, 465 }; 466 467 static void um_pci_rescan(void) 468 { 469 pci_lock_rescan_remove(); 470 pci_rescan_bus(bridge->bus); 471 pci_unlock_rescan_remove(); 472 } 473 474 static void um_pci_irq_vq_addbuf(struct virtqueue *vq, void *buf, bool kick) 475 { 476 struct scatterlist sg[1]; 477 478 sg_init_one(sg, buf, MAX_IRQ_MSG_SIZE); 479 if (virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC)) 480 kfree(buf); 481 else if (kick) 482 virtqueue_kick(vq); 483 } 484 485 static void um_pci_handle_irq_message(struct virtqueue *vq, 486 struct virtio_pcidev_msg *msg) 487 { 488 struct virtio_device *vdev = vq->vdev; 489 struct um_pci_device *dev = vdev->priv; 490 491 if (!dev->irq) 492 return; 493 494 /* we should properly chain interrupts, but on ARCH=um we don't care */ 495 496 switch (msg->op) { 497 case VIRTIO_PCIDEV_OP_INT: 498 generic_handle_irq(dev->irq); 499 break; 500 case VIRTIO_PCIDEV_OP_MSI: 501 /* our MSI message is just the interrupt number */ 502 if (msg->size == sizeof(u32)) 503 generic_handle_irq(le32_to_cpup((void *)msg->data)); 504 else 505 generic_handle_irq(le16_to_cpup((void *)msg->data)); 506 break; 507 case VIRTIO_PCIDEV_OP_PME: 508 /* nothing to do - we already woke up due to the message */ 509 break; 510 default: 511 dev_err(&vdev->dev, "unexpected virt-pci message %d\n", msg->op); 512 break; 513 } 514 } 515 516 static void um_pci_cmd_vq_cb(struct virtqueue *vq) 517 { 518 struct virtio_device *vdev = vq->vdev; 519 struct um_pci_device *dev = vdev->priv; 520 void *cmd; 521 int len; 522 523 if (test_bit(UM_PCI_STAT_WAITING, &dev->status)) 524 return; 525 526 while ((cmd = virtqueue_get_buf(vq, &len))) { 527 if (WARN_ON(HANDLE_IS_NO_FREE(cmd))) 528 continue; 529 kfree(cmd); 530 } 531 } 532 533 static void um_pci_irq_vq_cb(struct virtqueue *vq) 534 { 535 struct virtio_pcidev_msg *msg; 536 int len; 537 538 while ((msg = virtqueue_get_buf(vq, &len))) { 539 if (len >= sizeof(*msg)) 540 um_pci_handle_irq_message(vq, msg); 541 542 /* recycle the message buffer */ 543 um_pci_irq_vq_addbuf(vq, msg, true); 544 } 545 } 546 547 #ifdef CONFIG_OF 548 /* Copied from arch/x86/kernel/devicetree.c */ 549 struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus) 550 { 551 struct device_node *np; 552 553 for_each_node_by_type(np, "pci") { 554 const void *prop; 555 unsigned int bus_min; 556 557 prop = of_get_property(np, "bus-range", NULL); 558 if (!prop) 559 continue; 560 bus_min = be32_to_cpup(prop); 561 if (bus->number == bus_min) 562 return np; 563 } 564 return NULL; 565 } 566 #endif 567 568 static int um_pci_init_vqs(struct um_pci_device *dev) 569 { 570 struct virtqueue *vqs[2]; 571 static const char *const names[2] = { "cmd", "irq" }; 572 vq_callback_t *cbs[2] = { um_pci_cmd_vq_cb, um_pci_irq_vq_cb }; 573 int err, i; 574 575 err = virtio_find_vqs(dev->vdev, 2, vqs, cbs, names, NULL); 576 if (err) 577 return err; 578 579 dev->cmd_vq = vqs[0]; 580 dev->irq_vq = vqs[1]; 581 582 virtio_device_ready(dev->vdev); 583 584 for (i = 0; i < NUM_IRQ_MSGS; i++) { 585 void *msg = kzalloc(MAX_IRQ_MSG_SIZE, GFP_KERNEL); 586 587 if (msg) 588 um_pci_irq_vq_addbuf(dev->irq_vq, msg, false); 589 } 590 591 virtqueue_kick(dev->irq_vq); 592 593 return 0; 594 } 595 596 static void __um_pci_virtio_platform_remove(struct virtio_device *vdev, 597 struct um_pci_device *dev) 598 { 599 virtio_reset_device(vdev); 600 vdev->config->del_vqs(vdev); 601 602 mutex_lock(&um_pci_mtx); 603 um_pci_platform_device = NULL; 604 mutex_unlock(&um_pci_mtx); 605 606 kfree(dev); 607 } 608 609 static int um_pci_virtio_platform_probe(struct virtio_device *vdev, 610 struct um_pci_device *dev) 611 { 612 int ret; 613 614 dev->platform = true; 615 616 mutex_lock(&um_pci_mtx); 617 618 if (um_pci_platform_device) { 619 mutex_unlock(&um_pci_mtx); 620 ret = -EBUSY; 621 goto out_free; 622 } 623 624 ret = um_pci_init_vqs(dev); 625 if (ret) { 626 mutex_unlock(&um_pci_mtx); 627 goto out_free; 628 } 629 630 um_pci_platform_device = dev; 631 632 mutex_unlock(&um_pci_mtx); 633 634 ret = of_platform_default_populate(vdev->dev.of_node, NULL, &vdev->dev); 635 if (ret) 636 __um_pci_virtio_platform_remove(vdev, dev); 637 638 return ret; 639 640 out_free: 641 kfree(dev); 642 return ret; 643 } 644 645 static int um_pci_virtio_probe(struct virtio_device *vdev) 646 { 647 struct um_pci_device *dev; 648 int i, free = -1; 649 int err = -ENOSPC; 650 651 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 652 if (!dev) 653 return -ENOMEM; 654 655 dev->vdev = vdev; 656 vdev->priv = dev; 657 658 if (of_device_is_compatible(vdev->dev.of_node, "simple-bus")) 659 return um_pci_virtio_platform_probe(vdev, dev); 660 661 mutex_lock(&um_pci_mtx); 662 for (i = 0; i < MAX_DEVICES; i++) { 663 if (um_pci_devices[i].dev) 664 continue; 665 free = i; 666 break; 667 } 668 669 if (free < 0) 670 goto error; 671 672 err = um_pci_init_vqs(dev); 673 if (err) 674 goto error; 675 676 dev->irq = irq_alloc_desc(numa_node_id()); 677 if (dev->irq < 0) { 678 err = dev->irq; 679 goto err_reset; 680 } 681 um_pci_devices[free].dev = dev; 682 vdev->priv = dev; 683 684 mutex_unlock(&um_pci_mtx); 685 686 device_set_wakeup_enable(&vdev->dev, true); 687 688 /* 689 * In order to do suspend-resume properly, don't allow VQs 690 * to be suspended. 691 */ 692 virtio_uml_set_no_vq_suspend(vdev, true); 693 694 um_pci_rescan(); 695 return 0; 696 err_reset: 697 virtio_reset_device(vdev); 698 vdev->config->del_vqs(vdev); 699 error: 700 mutex_unlock(&um_pci_mtx); 701 kfree(dev); 702 return err; 703 } 704 705 static void um_pci_virtio_remove(struct virtio_device *vdev) 706 { 707 struct um_pci_device *dev = vdev->priv; 708 int i; 709 710 if (dev->platform) { 711 of_platform_depopulate(&vdev->dev); 712 __um_pci_virtio_platform_remove(vdev, dev); 713 return; 714 } 715 716 device_set_wakeup_enable(&vdev->dev, false); 717 718 mutex_lock(&um_pci_mtx); 719 for (i = 0; i < MAX_DEVICES; i++) { 720 if (um_pci_devices[i].dev != dev) 721 continue; 722 723 um_pci_devices[i].dev = NULL; 724 irq_free_desc(dev->irq); 725 726 break; 727 } 728 mutex_unlock(&um_pci_mtx); 729 730 if (i < MAX_DEVICES) { 731 struct pci_dev *pci_dev; 732 733 pci_dev = pci_get_slot(bridge->bus, i); 734 if (pci_dev) 735 pci_stop_and_remove_bus_device_locked(pci_dev); 736 } 737 738 /* Stop all virtqueues */ 739 virtio_reset_device(vdev); 740 dev->cmd_vq = NULL; 741 dev->irq_vq = NULL; 742 vdev->config->del_vqs(vdev); 743 744 kfree(dev); 745 } 746 747 static struct virtio_device_id id_table[] = { 748 { CONFIG_UML_PCI_OVER_VIRTIO_DEVICE_ID, VIRTIO_DEV_ANY_ID }, 749 { 0 }, 750 }; 751 MODULE_DEVICE_TABLE(virtio, id_table); 752 753 static struct virtio_driver um_pci_virtio_driver = { 754 .driver.name = "virtio-pci", 755 .driver.owner = THIS_MODULE, 756 .id_table = id_table, 757 .probe = um_pci_virtio_probe, 758 .remove = um_pci_virtio_remove, 759 }; 760 761 static struct resource virt_cfgspace_resource = { 762 .name = "PCI config space", 763 .start = 0xf0000000 - MAX_DEVICES * CFG_SPACE_SIZE, 764 .end = 0xf0000000 - 1, 765 .flags = IORESOURCE_MEM, 766 }; 767 768 static long um_pci_map_cfgspace(unsigned long offset, size_t size, 769 const struct logic_iomem_ops **ops, 770 void **priv) 771 { 772 if (WARN_ON(size > CFG_SPACE_SIZE || offset % CFG_SPACE_SIZE)) 773 return -EINVAL; 774 775 if (offset / CFG_SPACE_SIZE < MAX_DEVICES) { 776 *ops = &um_pci_device_cfgspace_ops; 777 *priv = &um_pci_devices[offset / CFG_SPACE_SIZE]; 778 return 0; 779 } 780 781 WARN(1, "cannot map offset 0x%lx/0x%zx\n", offset, size); 782 return -ENOENT; 783 } 784 785 static const struct logic_iomem_region_ops um_pci_cfgspace_ops = { 786 .map = um_pci_map_cfgspace, 787 }; 788 789 static struct resource virt_iomem_resource = { 790 .name = "PCI iomem", 791 .start = 0xf0000000, 792 .end = 0xffffffff, 793 .flags = IORESOURCE_MEM, 794 }; 795 796 struct um_pci_map_iomem_data { 797 unsigned long offset; 798 size_t size; 799 const struct logic_iomem_ops **ops; 800 void **priv; 801 long ret; 802 }; 803 804 static int um_pci_map_iomem_walk(struct pci_dev *pdev, void *_data) 805 { 806 struct um_pci_map_iomem_data *data = _data; 807 struct um_pci_device_reg *reg = &um_pci_devices[pdev->devfn / 8]; 808 struct um_pci_device *dev; 809 int i; 810 811 if (!reg->dev) 812 return 0; 813 814 for (i = 0; i < ARRAY_SIZE(dev->resptr); i++) { 815 struct resource *r = &pdev->resource[i]; 816 817 if ((r->flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) 818 continue; 819 820 /* 821 * must be the whole or part of the resource, 822 * not allowed to only overlap 823 */ 824 if (data->offset < r->start || data->offset > r->end) 825 continue; 826 if (data->offset + data->size - 1 > r->end) 827 continue; 828 829 dev = reg->dev; 830 *data->ops = &um_pci_device_bar_ops; 831 dev->resptr[i] = i; 832 *data->priv = &dev->resptr[i]; 833 data->ret = data->offset - r->start; 834 835 /* no need to continue */ 836 return 1; 837 } 838 839 return 0; 840 } 841 842 static long um_pci_map_iomem(unsigned long offset, size_t size, 843 const struct logic_iomem_ops **ops, 844 void **priv) 845 { 846 struct um_pci_map_iomem_data data = { 847 /* we want the full address here */ 848 .offset = offset + virt_iomem_resource.start, 849 .size = size, 850 .ops = ops, 851 .priv = priv, 852 .ret = -ENOENT, 853 }; 854 855 pci_walk_bus(bridge->bus, um_pci_map_iomem_walk, &data); 856 return data.ret; 857 } 858 859 static const struct logic_iomem_region_ops um_pci_iomem_ops = { 860 .map = um_pci_map_iomem, 861 }; 862 863 static void um_pci_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 864 { 865 /* 866 * This is a very low address and not actually valid 'physical' memory 867 * in UML, so we can simply map MSI(-X) vectors to there, it cannot be 868 * legitimately written to by the device in any other way. 869 * We use the (virtual) IRQ number here as the message to simplify the 870 * code that receives the message, where for now we simply trust the 871 * device to send the correct message. 872 */ 873 msg->address_hi = 0; 874 msg->address_lo = 0xa0000; 875 msg->data = data->irq; 876 } 877 878 static struct irq_chip um_pci_msi_bottom_irq_chip = { 879 .name = "UM virtio MSI", 880 .irq_compose_msi_msg = um_pci_compose_msi_msg, 881 }; 882 883 static int um_pci_inner_domain_alloc(struct irq_domain *domain, 884 unsigned int virq, unsigned int nr_irqs, 885 void *args) 886 { 887 unsigned long bit; 888 889 WARN_ON(nr_irqs != 1); 890 891 mutex_lock(&um_pci_mtx); 892 bit = find_first_zero_bit(um_pci_msi_used, MAX_MSI_VECTORS); 893 if (bit >= MAX_MSI_VECTORS) { 894 mutex_unlock(&um_pci_mtx); 895 return -ENOSPC; 896 } 897 898 set_bit(bit, um_pci_msi_used); 899 mutex_unlock(&um_pci_mtx); 900 901 irq_domain_set_info(domain, virq, bit, &um_pci_msi_bottom_irq_chip, 902 domain->host_data, handle_simple_irq, 903 NULL, NULL); 904 905 return 0; 906 } 907 908 static void um_pci_inner_domain_free(struct irq_domain *domain, 909 unsigned int virq, unsigned int nr_irqs) 910 { 911 struct irq_data *d = irq_domain_get_irq_data(domain, virq); 912 913 mutex_lock(&um_pci_mtx); 914 915 if (!test_bit(d->hwirq, um_pci_msi_used)) 916 pr_err("trying to free unused MSI#%lu\n", d->hwirq); 917 else 918 __clear_bit(d->hwirq, um_pci_msi_used); 919 920 mutex_unlock(&um_pci_mtx); 921 } 922 923 static const struct irq_domain_ops um_pci_inner_domain_ops = { 924 .alloc = um_pci_inner_domain_alloc, 925 .free = um_pci_inner_domain_free, 926 }; 927 928 static struct irq_chip um_pci_msi_irq_chip = { 929 .name = "UM virtio PCIe MSI", 930 .irq_mask = pci_msi_mask_irq, 931 .irq_unmask = pci_msi_unmask_irq, 932 }; 933 934 static struct msi_domain_info um_pci_msi_domain_info = { 935 .flags = MSI_FLAG_USE_DEF_DOM_OPS | 936 MSI_FLAG_USE_DEF_CHIP_OPS | 937 MSI_FLAG_PCI_MSIX, 938 .chip = &um_pci_msi_irq_chip, 939 }; 940 941 static struct resource busn_resource = { 942 .name = "PCI busn", 943 .start = 0, 944 .end = 0, 945 .flags = IORESOURCE_BUS, 946 }; 947 948 static int um_pci_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin) 949 { 950 struct um_pci_device_reg *reg = &um_pci_devices[pdev->devfn / 8]; 951 952 if (WARN_ON(!reg->dev)) 953 return -EINVAL; 954 955 /* Yes, we map all pins to the same IRQ ... doesn't matter for now. */ 956 return reg->dev->irq; 957 } 958 959 void *pci_root_bus_fwnode(struct pci_bus *bus) 960 { 961 return um_pci_fwnode; 962 } 963 964 static long um_pci_map_platform(unsigned long offset, size_t size, 965 const struct logic_iomem_ops **ops, 966 void **priv) 967 { 968 if (!um_pci_platform_device) 969 return -ENOENT; 970 971 *ops = &um_pci_device_bar_ops; 972 *priv = &um_pci_platform_device->resptr[0]; 973 974 return offset; 975 } 976 977 static const struct logic_iomem_region_ops um_pci_platform_ops = { 978 .map = um_pci_map_platform, 979 }; 980 981 static struct resource virt_platform_resource = { 982 .name = "platform", 983 .start = 0x10000000, 984 .end = 0x1fffffff, 985 .flags = IORESOURCE_MEM, 986 }; 987 988 static int __init um_pci_init(void) 989 { 990 int err, i; 991 992 WARN_ON(logic_iomem_add_region(&virt_cfgspace_resource, 993 &um_pci_cfgspace_ops)); 994 WARN_ON(logic_iomem_add_region(&virt_iomem_resource, 995 &um_pci_iomem_ops)); 996 WARN_ON(logic_iomem_add_region(&virt_platform_resource, 997 &um_pci_platform_ops)); 998 999 if (WARN(CONFIG_UML_PCI_OVER_VIRTIO_DEVICE_ID < 0, 1000 "No virtio device ID configured for PCI - no PCI support\n")) 1001 return 0; 1002 1003 um_pci_msg_bufs = alloc_percpu(struct um_pci_message_buffer); 1004 if (!um_pci_msg_bufs) 1005 return -ENOMEM; 1006 1007 bridge = pci_alloc_host_bridge(0); 1008 if (!bridge) { 1009 err = -ENOMEM; 1010 goto free; 1011 } 1012 1013 um_pci_fwnode = irq_domain_alloc_named_fwnode("um-pci"); 1014 if (!um_pci_fwnode) { 1015 err = -ENOMEM; 1016 goto free; 1017 } 1018 1019 um_pci_inner_domain = __irq_domain_add(um_pci_fwnode, MAX_MSI_VECTORS, 1020 MAX_MSI_VECTORS, 0, 1021 &um_pci_inner_domain_ops, NULL); 1022 if (!um_pci_inner_domain) { 1023 err = -ENOMEM; 1024 goto free; 1025 } 1026 1027 um_pci_msi_domain = pci_msi_create_irq_domain(um_pci_fwnode, 1028 &um_pci_msi_domain_info, 1029 um_pci_inner_domain); 1030 if (!um_pci_msi_domain) { 1031 err = -ENOMEM; 1032 goto free; 1033 } 1034 1035 pci_add_resource(&bridge->windows, &virt_iomem_resource); 1036 pci_add_resource(&bridge->windows, &busn_resource); 1037 bridge->ops = &um_pci_ops; 1038 bridge->map_irq = um_pci_map_irq; 1039 1040 for (i = 0; i < MAX_DEVICES; i++) { 1041 resource_size_t start; 1042 1043 start = virt_cfgspace_resource.start + i * CFG_SPACE_SIZE; 1044 um_pci_devices[i].iomem = ioremap(start, CFG_SPACE_SIZE); 1045 if (WARN(!um_pci_devices[i].iomem, "failed to map %d\n", i)) { 1046 err = -ENOMEM; 1047 goto free; 1048 } 1049 } 1050 1051 err = pci_host_probe(bridge); 1052 if (err) 1053 goto free; 1054 1055 err = register_virtio_driver(&um_pci_virtio_driver); 1056 if (err) 1057 goto free; 1058 return 0; 1059 free: 1060 if (um_pci_inner_domain) 1061 irq_domain_remove(um_pci_inner_domain); 1062 if (um_pci_fwnode) 1063 irq_domain_free_fwnode(um_pci_fwnode); 1064 if (bridge) { 1065 pci_free_resource_list(&bridge->windows); 1066 pci_free_host_bridge(bridge); 1067 } 1068 free_percpu(um_pci_msg_bufs); 1069 return err; 1070 } 1071 module_init(um_pci_init); 1072 1073 static void __exit um_pci_exit(void) 1074 { 1075 unregister_virtio_driver(&um_pci_virtio_driver); 1076 irq_domain_remove(um_pci_msi_domain); 1077 irq_domain_remove(um_pci_inner_domain); 1078 pci_free_resource_list(&bridge->windows); 1079 pci_free_host_bridge(bridge); 1080 free_percpu(um_pci_msg_bufs); 1081 } 1082 module_exit(um_pci_exit); 1083