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
um_pci_send_cmd(struct um_pci_device * dev,struct virtio_pcidev_msg * cmd,unsigned int cmd_size,const void * extra,unsigned int extra_size,void * out,unsigned int out_size)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
um_pci_cfgspace_read(void * priv,unsigned int offset,int size)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
um_pci_cfgspace_write(void * priv,unsigned int offset,int size,unsigned long val)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
um_pci_bar_copy_from(void * priv,void * buffer,unsigned int offset,int size)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
um_pci_bar_read(void * priv,unsigned int offset,int size)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
um_pci_bar_copy_to(void * priv,unsigned int offset,const void * buffer,int size)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
um_pci_bar_write(void * priv,unsigned int offset,int size,unsigned long val)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
um_pci_bar_set(void * priv,unsigned int offset,u8 value,int size)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
um_pci_map_bus(struct pci_bus * bus,unsigned int devfn,int where)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
um_pci_rescan(void)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
um_pci_irq_vq_addbuf(struct virtqueue * vq,void * buf,bool kick)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
um_pci_handle_irq_message(struct virtqueue * vq,struct virtio_pcidev_msg * msg)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
um_pci_cmd_vq_cb(struct virtqueue * vq)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
um_pci_irq_vq_cb(struct virtqueue * vq)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 */
pcibios_get_phb_of_node(struct pci_bus * bus)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
um_pci_init_vqs(struct um_pci_device * dev)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
__um_pci_virtio_platform_remove(struct virtio_device * vdev,struct um_pci_device * dev)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
um_pci_virtio_platform_probe(struct virtio_device * vdev,struct um_pci_device * dev)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
um_pci_virtio_probe(struct virtio_device * vdev)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
um_pci_virtio_remove(struct virtio_device * vdev)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
um_pci_map_cfgspace(unsigned long offset,size_t size,const struct logic_iomem_ops ** ops,void ** priv)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
um_pci_map_iomem_walk(struct pci_dev * pdev,void * _data)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
um_pci_map_iomem(unsigned long offset,size_t size,const struct logic_iomem_ops ** ops,void ** priv)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
um_pci_compose_msi_msg(struct irq_data * data,struct msi_msg * msg)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
um_pci_inner_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * args)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
um_pci_inner_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)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
um_pci_map_irq(const struct pci_dev * pdev,u8 slot,u8 pin)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
pci_root_bus_fwnode(struct pci_bus * bus)959 void *pci_root_bus_fwnode(struct pci_bus *bus)
960 {
961 return um_pci_fwnode;
962 }
963
um_pci_map_platform(unsigned long offset,size_t size,const struct logic_iomem_ops ** ops,void ** priv)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
um_pci_init(void)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
um_pci_exit(void)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