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Merge tag 'char-misc-4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
[deliverable/linux.git] / drivers / misc / mic / vop / vop_vringh.c
CommitLineData
61e9c905
SD		 1/*
2 * Intel MIC Platform Software Stack (MPSS)
3 *
4 * Copyright(c) 2016 Intel Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * The full GNU General Public License is included in this distribution in
16 * the file called "COPYING".
17 *
18 * Intel Virtio Over PCIe (VOP) driver.
19 *
20 */
21#include <linux/sched.h>
22#include <linux/poll.h>
23#include <linux/dma-mapping.h>
24
25#include <linux/mic_common.h>
26#include "../common/mic_dev.h"
27
28#include <linux/mic_ioctl.h>
29#include "vop_main.h"
30
31/* Helper API to obtain the VOP PCIe device */
32static inline struct device *vop_dev(struct vop_vdev *vdev)
33{
34 return vdev->vpdev->dev.parent;
35}
36
37/* Helper API to check if a virtio device is initialized */
38static inline int vop_vdev_inited(struct vop_vdev *vdev)
39{
40 if (!vdev)
41 return -EINVAL;
42 /* Device has not been created yet */
43 if (!vdev->dd || !vdev->dd->type) {
44 dev_err(vop_dev(vdev), "%s %d err %d\n",
45 __func__, __LINE__, -EINVAL);
46 return -EINVAL;
47 }
48 /* Device has been removed/deleted */
49 if (vdev->dd->type == -1) {
50 dev_dbg(vop_dev(vdev), "%s %d err %d\n",
51 __func__, __LINE__, -ENODEV);
52 return -ENODEV;
53 }
54 return 0;
55}
56
57static void _vop_notify(struct vringh *vrh)
58{
59 struct vop_vringh *vvrh = container_of(vrh, struct vop_vringh, vrh);
60 struct vop_vdev *vdev = vvrh->vdev;
61 struct vop_device *vpdev = vdev->vpdev;
62 s8 db = vdev->dc->h2c_vdev_db;
63
64 if (db != -1)
65 vpdev->hw_ops->send_intr(vpdev, db);
66}
67
68static void vop_virtio_init_post(struct vop_vdev *vdev)
69{
70 struct mic_vqconfig *vqconfig = mic_vq_config(vdev->dd);
71 struct vop_device *vpdev = vdev->vpdev;
72 int i, used_size;
73
74 for (i = 0; i < vdev->dd->num_vq; i++) {
75 used_size = PAGE_ALIGN(sizeof(u16) * 3 +
76 sizeof(struct vring_used_elem) *
77 le16_to_cpu(vqconfig->num));
78 if (!le64_to_cpu(vqconfig[i].used_address)) {
79 dev_warn(vop_dev(vdev), "used_address zero??\n");
80 continue;
81 }
82 vdev->vvr[i].vrh.vring.used =
83 (void __force *)vpdev->hw_ops->ioremap(
84 vpdev,
85 le64_to_cpu(vqconfig[i].used_address),
86 used_size);
87 }
88
89 vdev->dc->used_address_updated = 0;
90
91 dev_info(vop_dev(vdev), "%s: device type %d LINKUP\n",
92 __func__, vdev->virtio_id);
93}
94
95static inline void vop_virtio_device_reset(struct vop_vdev *vdev)
96{
97 int i;
98
99 dev_dbg(vop_dev(vdev), "%s: status %d device type %d RESET\n",
100 __func__, vdev->dd->status, vdev->virtio_id);
101
102 for (i = 0; i < vdev->dd->num_vq; i++)
103 /*
104 * Avoid lockdep false positive. The + 1 is for the vop
105 * mutex which is held in the reset devices code path.
106 */
107 mutex_lock_nested(&vdev->vvr[i].vr_mutex, i + 1);
108
109 /* 0 status means "reset" */
110 vdev->dd->status = 0;
111 vdev->dc->vdev_reset = 0;
112 vdev->dc->host_ack = 1;
113
114 for (i = 0; i < vdev->dd->num_vq; i++) {
115 struct vringh *vrh = &vdev->vvr[i].vrh;
116
117 vdev->vvr[i].vring.info->avail_idx = 0;
118 vrh->completed = 0;
119 vrh->last_avail_idx = 0;
120 vrh->last_used_idx = 0;
121 }
122
123 for (i = 0; i < vdev->dd->num_vq; i++)
124 mutex_unlock(&vdev->vvr[i].vr_mutex);
125}
126
127static void vop_virtio_reset_devices(struct vop_info *vi)
128{
129 struct list_head *pos, *tmp;
130 struct vop_vdev *vdev;
131
132 list_for_each_safe(pos, tmp, &vi->vdev_list) {
133 vdev = list_entry(pos, struct vop_vdev, list);
134 vop_virtio_device_reset(vdev);
135 vdev->poll_wake = 1;
136 wake_up(&vdev->waitq);
137 }
138}
139
140static void vop_bh_handler(struct work_struct *work)
141{
142 struct vop_vdev *vdev = container_of(work, struct vop_vdev,
143 virtio_bh_work);
144
145 if (vdev->dc->used_address_updated)
146 vop_virtio_init_post(vdev);
147
148 if (vdev->dc->vdev_reset)
149 vop_virtio_device_reset(vdev);
150
151 vdev->poll_wake = 1;
152 wake_up(&vdev->waitq);
153}
154
155static irqreturn_t _vop_virtio_intr_handler(int irq, void *data)
156{
157 struct vop_vdev *vdev = data;
158 struct vop_device *vpdev = vdev->vpdev;
159
160 vpdev->hw_ops->ack_interrupt(vpdev, vdev->virtio_db);
161 schedule_work(&vdev->virtio_bh_work);
162 return IRQ_HANDLED;
163}
164
165static int vop_virtio_config_change(struct vop_vdev *vdev, void *argp)
166{
167 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
168 int ret = 0, retry, i;
169 struct vop_device *vpdev = vdev->vpdev;
170 struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
171 struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
172 s8 db = bootparam->h2c_config_db;
173
174 mutex_lock(&vi->vop_mutex);
175 for (i = 0; i < vdev->dd->num_vq; i++)
176 mutex_lock_nested(&vdev->vvr[i].vr_mutex, i + 1);
177
178 if (db == -1 || vdev->dd->type == -1) {
179 ret = -EIO;
180 goto exit;
181 }
182
183 memcpy(mic_vq_configspace(vdev->dd), argp, vdev->dd->config_len);
184 vdev->dc->config_change = MIC_VIRTIO_PARAM_CONFIG_CHANGED;
185 vpdev->hw_ops->send_intr(vpdev, db);
186
187 for (retry = 100; retry--;) {
188 ret = wait_event_timeout(wake, vdev->dc->guest_ack,
189 msecs_to_jiffies(100));
190 if (ret)
191 break;
192 }
193
194 dev_dbg(vop_dev(vdev),
195 "%s %d retry: %d\n", __func__, __LINE__, retry);
196 vdev->dc->config_change = 0;
197 vdev->dc->guest_ack = 0;
198exit:
199 for (i = 0; i < vdev->dd->num_vq; i++)
200 mutex_unlock(&vdev->vvr[i].vr_mutex);
201 mutex_unlock(&vi->vop_mutex);
202 return ret;
203}
204
205static int vop_copy_dp_entry(struct vop_vdev *vdev,
206 struct mic_device_desc *argp, __u8 *type,
207 struct mic_device_desc **devpage)
208{
209 struct vop_device *vpdev = vdev->vpdev;
210 struct mic_device_desc *devp;
211 struct mic_vqconfig *vqconfig;
212 int ret = 0, i;
213 bool slot_found = false;
214
215 vqconfig = mic_vq_config(argp);
216 for (i = 0; i < argp->num_vq; i++) {
217 if (le16_to_cpu(vqconfig[i].num) > MIC_MAX_VRING_ENTRIES) {
218 ret = -EINVAL;
219 dev_err(vop_dev(vdev), "%s %d err %d\n",
220 __func__, __LINE__, ret);
221 goto exit;
222 }
223 }
224
225 /* Find the first free device page entry */
226 for (i = sizeof(struct mic_bootparam);
227 i < MIC_DP_SIZE - mic_total_desc_size(argp);
228 i += mic_total_desc_size(devp)) {
229 devp = vpdev->hw_ops->get_dp(vpdev) + i;
230 if (devp->type == 0 || devp->type == -1) {
231 slot_found = true;
232 break;
233 }
234 }
235 if (!slot_found) {
236 ret = -EINVAL;
237 dev_err(vop_dev(vdev), "%s %d err %d\n",
238 __func__, __LINE__, ret);
239 goto exit;
240 }
241 /*
242 * Save off the type before doing the memcpy. Type will be set in the
243 * end after completing all initialization for the new device.
244 */
245 *type = argp->type;
246 argp->type = 0;
247 memcpy(devp, argp, mic_desc_size(argp));
248
249 *devpage = devp;
250exit:
251 return ret;
252}
253
254static void vop_init_device_ctrl(struct vop_vdev *vdev,
255 struct mic_device_desc *devpage)
256{
257 struct mic_device_ctrl *dc;
258
259 dc = (void *)devpage + mic_aligned_desc_size(devpage);
260
261 dc->config_change = 0;
262 dc->guest_ack = 0;
263 dc->vdev_reset = 0;
264 dc->host_ack = 0;
265 dc->used_address_updated = 0;
266 dc->c2h_vdev_db = -1;
267 dc->h2c_vdev_db = -1;
268 vdev->dc = dc;
269}
270
271static int vop_virtio_add_device(struct vop_vdev *vdev,
272 struct mic_device_desc *argp)
273{
274 struct vop_info *vi = vdev->vi;
275 struct vop_device *vpdev = vi->vpdev;
276 struct mic_device_desc *dd = NULL;
277 struct mic_vqconfig *vqconfig;
278 int vr_size, i, j, ret;
279 u8 type = 0;
280 s8 db = -1;
281 char irqname[16];
282 struct mic_bootparam *bootparam;
283 u16 num;
284 dma_addr_t vr_addr;
285
286 bootparam = vpdev->hw_ops->get_dp(vpdev);
287 init_waitqueue_head(&vdev->waitq);
288 INIT_LIST_HEAD(&vdev->list);
289 vdev->vpdev = vpdev;
290
291 ret = vop_copy_dp_entry(vdev, argp, &type, &dd);
292 if (ret) {
61e9c905
SD		 293 dev_err(vop_dev(vdev), "%s %d err %d\n",
294 __func__, __LINE__, ret);
6ddf2f0c 295 kfree(vdev);
61e9c905
SD		 296 return ret;
297 }
298
299 vop_init_device_ctrl(vdev, dd);
300
301 vdev->dd = dd;
302 vdev->virtio_id = type;
303 vqconfig = mic_vq_config(dd);
304 INIT_WORK(&vdev->virtio_bh_work, vop_bh_handler);
305
306 for (i = 0; i < dd->num_vq; i++) {
307 struct vop_vringh *vvr = &vdev->vvr[i];
308 struct mic_vring *vr = &vdev->vvr[i].vring;
309
310 num = le16_to_cpu(vqconfig[i].num);
311 mutex_init(&vvr->vr_mutex);
312 vr_size = PAGE_ALIGN(vring_size(num, MIC_VIRTIO_RING_ALIGN) +
313 sizeof(struct _mic_vring_info));
314 vr->va = (void *)
315 __get_free_pages(GFP_KERNEL | __GFP_ZERO,
316 get_order(vr_size));
317 if (!vr->va) {
318 ret = -ENOMEM;
319 dev_err(vop_dev(vdev), "%s %d err %d\n",
320 __func__, __LINE__, ret);
321 goto err;
322 }
323 vr->len = vr_size;
324 vr->info = vr->va + vring_size(num, MIC_VIRTIO_RING_ALIGN);
325 vr->info->magic = cpu_to_le32(MIC_MAGIC + vdev->virtio_id + i);
326 vr_addr = dma_map_single(&vpdev->dev, vr->va, vr_size,
327 DMA_BIDIRECTIONAL);
328 if (dma_mapping_error(&vpdev->dev, vr_addr)) {
329 free_pages((unsigned long)vr->va, get_order(vr_size));
330 ret = -ENOMEM;
331 dev_err(vop_dev(vdev), "%s %d err %d\n",
332 __func__, __LINE__, ret);
333 goto err;
334 }
335 vqconfig[i].address = cpu_to_le64(vr_addr);
336
337 vring_init(&vr->vr, num, vr->va, MIC_VIRTIO_RING_ALIGN);
338 ret = vringh_init_kern(&vvr->vrh,
339 *(u32 *)mic_vq_features(vdev->dd),
340 num, false, vr->vr.desc, vr->vr.avail,
341 vr->vr.used);
342 if (ret) {
343 dev_err(vop_dev(vdev), "%s %d err %d\n",
344 __func__, __LINE__, ret);
345 goto err;
346 }
347 vringh_kiov_init(&vvr->riov, NULL, 0);
348 vringh_kiov_init(&vvr->wiov, NULL, 0);
349 vvr->head = USHRT_MAX;
350 vvr->vdev = vdev;
351 vvr->vrh.notify = _vop_notify;
352 dev_dbg(&vpdev->dev,
353 "%s %d index %d va %p info %p vr_size 0x%x\n",
354 __func__, __LINE__, i, vr->va, vr->info, vr_size);
355 vvr->buf = (void *)__get_free_pages(GFP_KERNEL,
356 get_order(VOP_INT_DMA_BUF_SIZE));
357 vvr->buf_da = dma_map_single(&vpdev->dev,
358 vvr->buf, VOP_INT_DMA_BUF_SIZE,
359 DMA_BIDIRECTIONAL);
360 }
361
362 snprintf(irqname, sizeof(irqname), "vop%dvirtio%d", vpdev->index,
363 vdev->virtio_id);
364 vdev->virtio_db = vpdev->hw_ops->next_db(vpdev);
365 vdev->virtio_cookie = vpdev->hw_ops->request_irq(vpdev,
366 _vop_virtio_intr_handler, irqname, vdev,
367 vdev->virtio_db);
368 if (IS_ERR(vdev->virtio_cookie)) {
369 ret = PTR_ERR(vdev->virtio_cookie);
370 dev_dbg(&vpdev->dev, "request irq failed\n");
371 goto err;
372 }
373
374 vdev->dc->c2h_vdev_db = vdev->virtio_db;
375
376 /*
377 * Order the type update with previous stores. This write barrier
378 * is paired with the corresponding read barrier before the uncached
379 * system memory read of the type, on the card while scanning the
380 * device page.
381 */
382 smp_wmb();
383 dd->type = type;
384 argp->type = type;
385
386 if (bootparam) {
387 db = bootparam->h2c_config_db;
388 if (db != -1)
389 vpdev->hw_ops->send_intr(vpdev, db);
390 }
391 dev_dbg(&vpdev->dev, "Added virtio id %d db %d\n", dd->type, db);
392 return 0;
393err:
394 vqconfig = mic_vq_config(dd);
395 for (j = 0; j < i; j++) {
396 struct vop_vringh *vvr = &vdev->vvr[j];
397
398 dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[j].address),
399 vvr->vring.len, DMA_BIDIRECTIONAL);
400 free_pages((unsigned long)vvr->vring.va,
401 get_order(vvr->vring.len));
402 }
403 return ret;
404}
405
406static void vop_dev_remove(struct vop_info *pvi, struct mic_device_ctrl *devp,
407 struct vop_device *vpdev)
408{
409 struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
410 s8 db;
411 int ret, retry;
412 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
413
414 devp->config_change = MIC_VIRTIO_PARAM_DEV_REMOVE;
415 db = bootparam->h2c_config_db;
416 if (db != -1)
417 vpdev->hw_ops->send_intr(vpdev, db);
418 else
419 goto done;
420 for (retry = 15; retry--;) {
421 ret = wait_event_timeout(wake, devp->guest_ack,
422 msecs_to_jiffies(1000));
423 if (ret)
424 break;
425 }
426done:
427 devp->config_change = 0;
428 devp->guest_ack = 0;
429}
430
431static void vop_virtio_del_device(struct vop_vdev *vdev)
432{
433 struct vop_info *vi = vdev->vi;
434 struct vop_device *vpdev = vdev->vpdev;
435 int i;
436 struct mic_vqconfig *vqconfig;
437 struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
438
439 if (!bootparam)
440 goto skip_hot_remove;
441 vop_dev_remove(vi, vdev->dc, vpdev);
442skip_hot_remove:
443 vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
444 flush_work(&vdev->virtio_bh_work);
445 vqconfig = mic_vq_config(vdev->dd);
446 for (i = 0; i < vdev->dd->num_vq; i++) {
447 struct vop_vringh *vvr = &vdev->vvr[i];
448
449 dma_unmap_single(&vpdev->dev,
450 vvr->buf_da, VOP_INT_DMA_BUF_SIZE,
451 DMA_BIDIRECTIONAL);
452 free_pages((unsigned long)vvr->buf,
453 get_order(VOP_INT_DMA_BUF_SIZE));
454 vringh_kiov_cleanup(&vvr->riov);
455 vringh_kiov_cleanup(&vvr->wiov);
456 dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[i].address),
457 vvr->vring.len, DMA_BIDIRECTIONAL);
458 free_pages((unsigned long)vvr->vring.va,
459 get_order(vvr->vring.len));
460 }
461 /*
462 * Order the type update with previous stores. This write barrier
463 * is paired with the corresponding read barrier before the uncached
464 * system memory read of the type, on the card while scanning the
465 * device page.
466 */
467 smp_wmb();
468 vdev->dd->type = -1;
469}
470
471/*
472 * vop_sync_dma - Wrapper for synchronous DMAs.
473 *
474 * @dev - The address of the pointer to the device instance used
475 * for DMA registration.
476 * @dst - destination DMA address.
477 * @src - source DMA address.
478 * @len - size of the transfer.
479 *
480 * Return DMA_SUCCESS on success
481 */
482static int vop_sync_dma(struct vop_vdev *vdev, dma_addr_t dst, dma_addr_t src,
483 size_t len)
484{
485 int err = 0;
486 struct dma_device *ddev;
487 struct dma_async_tx_descriptor *tx;
488 struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev);
489 struct dma_chan *vop_ch = vi->dma_ch;
490
491 if (!vop_ch) {
492 err = -EBUSY;
493 goto error;
494 }
495 ddev = vop_ch->device;
496 tx = ddev->device_prep_dma_memcpy(vop_ch, dst, src, len,
497 DMA_PREP_FENCE);
498 if (!tx) {
499 err = -ENOMEM;
500 goto error;
501 } else {
502 dma_cookie_t cookie;
503
504 cookie = tx->tx_submit(tx);
505 if (dma_submit_error(cookie)) {
506 err = -ENOMEM;
507 goto error;
508 }
509 dma_async_issue_pending(vop_ch);
510 err = dma_sync_wait(vop_ch, cookie);
511 }
512error:
513 if (err)
514 dev_err(&vi->vpdev->dev, "%s %d err %d\n",
515 __func__, __LINE__, err);
516 return err;
517}
518
519#define VOP_USE_DMA true
520
521/*
522 * Initiates the copies across the PCIe bus from card memory to a user
523 * space buffer. When transfers are done using DMA, source/destination
524 * addresses and transfer length must follow the alignment requirements of
525 * the MIC DMA engine.
526 */
527static int vop_virtio_copy_to_user(struct vop_vdev *vdev, void __user *ubuf,
528 size_t len, u64 daddr, size_t dlen,
529 int vr_idx)
530{
531 struct vop_device *vpdev = vdev->vpdev;
532 void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len);
533 struct vop_vringh *vvr = &vdev->vvr[vr_idx];
534 struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
535 size_t dma_alignment = 1 << vi->dma_ch->device->copy_align;
536 bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1);
537 size_t dma_offset, partlen;
538 int err;
539
540 if (!VOP_USE_DMA) {
541 if (copy_to_user(ubuf, (void __force *)dbuf, len)) {
542 err = -EFAULT;
543 dev_err(vop_dev(vdev), "%s %d err %d\n",
544 __func__, __LINE__, err);
545 goto err;
546 }
547 vdev->in_bytes += len;
548 err = 0;
549 goto err;
550 }
551
552 dma_offset = daddr - round_down(daddr, dma_alignment);
553 daddr -= dma_offset;
554 len += dma_offset;
555 /*
556 * X100 uses DMA addresses as seen by the card so adding
557 * the aperture base is not required for DMA. However x200
558 * requires DMA addresses to be an offset into the bar so
559 * add the aperture base for x200.
560 */
561 if (x200)
562 daddr += vpdev->aper->pa;
563 while (len) {
564 partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
565 err = vop_sync_dma(vdev, vvr->buf_da, daddr,
566 ALIGN(partlen, dma_alignment));
567 if (err) {
568 dev_err(vop_dev(vdev), "%s %d err %d\n",
569 __func__, __LINE__, err);
570 goto err;
571 }
572 if (copy_to_user(ubuf, vvr->buf + dma_offset,
573 partlen - dma_offset)) {
574 err = -EFAULT;
575 dev_err(vop_dev(vdev), "%s %d err %d\n",
576 __func__, __LINE__, err);
577 goto err;
578 }
579 daddr += partlen;
580 ubuf += partlen;
581 dbuf += partlen;
582 vdev->in_bytes_dma += partlen;
583 vdev->in_bytes += partlen;
584 len -= partlen;
585 dma_offset = 0;
586 }
587 err = 0;
588err:
589 vpdev->hw_ops->iounmap(vpdev, dbuf);
590 dev_dbg(vop_dev(vdev),
591 "%s: ubuf %p dbuf %p len 0x%lx vr_idx 0x%x\n",
592 __func__, ubuf, dbuf, len, vr_idx);
593 return err;
594}
595
596/*
597 * Initiates copies across the PCIe bus from a user space buffer to card
598 * memory. When transfers are done using DMA, source/destination addresses
599 * and transfer length must follow the alignment requirements of the MIC
600 * DMA engine.
601 */
602static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf,
603 size_t len, u64 daddr, size_t dlen,
604 int vr_idx)
605{
606 struct vop_device *vpdev = vdev->vpdev;
607 void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len);
608 struct vop_vringh *vvr = &vdev->vvr[vr_idx];
609 struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev);
610 size_t dma_alignment = 1 << vi->dma_ch->device->copy_align;
611 bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1);
612 size_t partlen;
613 bool dma = VOP_USE_DMA;
614 int err = 0;
615
616 if (daddr & (dma_alignment - 1)) {
617 vdev->tx_dst_unaligned += len;
618 dma = false;
619 } else if (ALIGN(len, dma_alignment) > dlen) {
620 vdev->tx_len_unaligned += len;
621 dma = false;
622 }
623
624 if (!dma)
625 goto memcpy;
626
627 /*
628 * X100 uses DMA addresses as seen by the card so adding
629 * the aperture base is not required for DMA. However x200
630 * requires DMA addresses to be an offset into the bar so
631 * add the aperture base for x200.
632 */
633 if (x200)
634 daddr += vpdev->aper->pa;
635 while (len) {
636 partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
637
638 if (copy_from_user(vvr->buf, ubuf, partlen)) {
639 err = -EFAULT;
640 dev_err(vop_dev(vdev), "%s %d err %d\n",
641 __func__, __LINE__, err);
642 goto err;
643 }
644 err = vop_sync_dma(vdev, daddr, vvr->buf_da,
645 ALIGN(partlen, dma_alignment));
646 if (err) {
647 dev_err(vop_dev(vdev), "%s %d err %d\n",
648 __func__, __LINE__, err);
649 goto err;
650 }
651 daddr += partlen;
652 ubuf += partlen;
653 dbuf += partlen;
654 vdev->out_bytes_dma += partlen;
655 vdev->out_bytes += partlen;
656 len -= partlen;
657 }
658memcpy:
659 /*
660 * We are copying to IO below and should ideally use something
661 * like copy_from_user_toio(..) if it existed.
662 */
663 if (copy_from_user((void __force *)dbuf, ubuf, len)) {
664 err = -EFAULT;
665 dev_err(vop_dev(vdev), "%s %d err %d\n",
666 __func__, __LINE__, err);
667 goto err;
668 }
669 vdev->out_bytes += len;
670 err = 0;
671err:
672 vpdev->hw_ops->iounmap(vpdev, dbuf);
673 dev_dbg(vop_dev(vdev),
674 "%s: ubuf %p dbuf %p len 0x%lx vr_idx 0x%x\n",
675 __func__, ubuf, dbuf, len, vr_idx);
676 return err;
677}
678
679#define MIC_VRINGH_READ true
680
681/* Determine the total number of bytes consumed in a VRINGH KIOV */
682static inline u32 vop_vringh_iov_consumed(struct vringh_kiov *iov)
683{
684 int i;
685 u32 total = iov->consumed;
686
687 for (i = 0; i < iov->i; i++)
688 total += iov->iov[i].iov_len;
689 return total;
690}
691
692/*
693 * Traverse the VRINGH KIOV and issue the APIs to trigger the copies.
694 * This API is heavily based on the vringh_iov_xfer(..) implementation
695 * in vringh.c. The reason we cannot reuse vringh_iov_pull_kern(..)
696 * and vringh_iov_push_kern(..) directly is because there is no
697 * way to override the VRINGH xfer(..) routines as of v3.10.
698 */
699static int vop_vringh_copy(struct vop_vdev *vdev, struct vringh_kiov *iov,
700 void __user *ubuf, size_t len, bool read, int vr_idx,
701 size_t *out_len)
702{
703 int ret = 0;
704 size_t partlen, tot_len = 0;
705
706 while (len && iov->i < iov->used) {
707 struct kvec *kiov = &iov->iov[iov->i];
708
709 partlen = min(kiov->iov_len, len);
710 if (read)
711 ret = vop_virtio_copy_to_user(vdev, ubuf, partlen,
712 (u64)kiov->iov_base,
713 kiov->iov_len,
714 vr_idx);
715 else
716 ret = vop_virtio_copy_from_user(vdev, ubuf, partlen,
717 (u64)kiov->iov_base,
718 kiov->iov_len,
719 vr_idx);
720 if (ret) {
721 dev_err(vop_dev(vdev), "%s %d err %d\n",
722 __func__, __LINE__, ret);
723 break;
724 }
725 len -= partlen;
726 ubuf += partlen;
727 tot_len += partlen;
728 iov->consumed += partlen;
729 kiov->iov_len -= partlen;
730 kiov->iov_base += partlen;
731 if (!kiov->iov_len) {
732 /* Fix up old iov element then increment. */
733 kiov->iov_len = iov->consumed;
734 kiov->iov_base -= iov->consumed;
735
736 iov->consumed = 0;
737 iov->i++;
738 }
739 }
740 *out_len = tot_len;
741 return ret;
742}
743
744/*
745 * Use the standard VRINGH infrastructure in the kernel to fetch new
746 * descriptors, initiate the copies and update the used ring.
747 */
748static int _vop_virtio_copy(struct vop_vdev *vdev, struct mic_copy_desc *copy)
749{
750 int ret = 0;
751 u32 iovcnt = copy->iovcnt;
752 struct iovec iov;
753 struct iovec __user *u_iov = copy->iov;
754 void __user *ubuf = NULL;
755 struct vop_vringh *vvr = &vdev->vvr[copy->vr_idx];
756 struct vringh_kiov *riov = &vvr->riov;
757 struct vringh_kiov *wiov = &vvr->wiov;
758 struct vringh *vrh = &vvr->vrh;
759 u16 *head = &vvr->head;
760 struct mic_vring *vr = &vvr->vring;
761 size_t len = 0, out_len;
762
763 copy->out_len = 0;
764 /* Fetch a new IOVEC if all previous elements have been processed */
765 if (riov->i == riov->used && wiov->i == wiov->used) {
766 ret = vringh_getdesc_kern(vrh, riov, wiov,
767 head, GFP_KERNEL);
768 /* Check if there are available descriptors */
769 if (ret <= 0)
770 return ret;
771 }
772 while (iovcnt) {
773 if (!len) {
774 /* Copy over a new iovec from user space. */
775 ret = copy_from_user(&iov, u_iov, sizeof(*u_iov));
776 if (ret) {
777 ret = -EINVAL;
778 dev_err(vop_dev(vdev), "%s %d err %d\n",
779 __func__, __LINE__, ret);
780 break;
781 }
782 len = iov.iov_len;
783 ubuf = iov.iov_base;
784 }
785 /* Issue all the read descriptors first */
786 ret = vop_vringh_copy(vdev, riov, ubuf, len,
787 MIC_VRINGH_READ, copy->vr_idx, &out_len);
788 if (ret) {
789 dev_err(vop_dev(vdev), "%s %d err %d\n",
790 __func__, __LINE__, ret);
791 break;
792 }
793 len -= out_len;
794 ubuf += out_len;
795 copy->out_len += out_len;
796 /* Issue the write descriptors next */
797 ret = vop_vringh_copy(vdev, wiov, ubuf, len,
798 !MIC_VRINGH_READ, copy->vr_idx, &out_len);
799 if (ret) {
800 dev_err(vop_dev(vdev), "%s %d err %d\n",
801 __func__, __LINE__, ret);
802 break;
803 }
804 len -= out_len;
805 ubuf += out_len;
806 copy->out_len += out_len;
807 if (!len) {
808 /* One user space iovec is now completed */
809 iovcnt--;
810 u_iov++;
811 }
812 /* Exit loop if all elements in KIOVs have been processed. */
813 if (riov->i == riov->used && wiov->i == wiov->used)
814 break;
815 }
816 /*
817 * Update the used ring if a descriptor was available and some data was
818 * copied in/out and the user asked for a used ring update.
819 */
820 if (*head != USHRT_MAX && copy->out_len && copy->update_used) {
821 u32 total = 0;
822
823 /* Determine the total data consumed */
824 total += vop_vringh_iov_consumed(riov);
825 total += vop_vringh_iov_consumed(wiov);
826 vringh_complete_kern(vrh, *head, total);
827 *head = USHRT_MAX;
828 if (vringh_need_notify_kern(vrh) > 0)
829 vringh_notify(vrh);
830 vringh_kiov_cleanup(riov);
831 vringh_kiov_cleanup(wiov);
832 /* Update avail idx for user space */
833 vr->info->avail_idx = vrh->last_avail_idx;
834 }
835 return ret;
836}
837
838static inline int vop_verify_copy_args(struct vop_vdev *vdev,
839 struct mic_copy_desc *copy)
840{
841 if (!vdev || copy->vr_idx >= vdev->dd->num_vq)
842 return -EINVAL;
843 return 0;
844}
845
846/* Copy a specified number of virtio descriptors in a chain */
847static int vop_virtio_copy_desc(struct vop_vdev *vdev,
848 struct mic_copy_desc *copy)
849{
850 int err;
59ea2590 851 struct vop_vringh *vvr;
61e9c905
SD		 852
853 err = vop_verify_copy_args(vdev, copy);
854 if (err)
855 return err;
856
59ea2590 857 vvr = &vdev->vvr[copy->vr_idx];
61e9c905
SD		 858 mutex_lock(&vvr->vr_mutex);
859 if (!vop_vdevup(vdev)) {
860 err = -ENODEV;
861 dev_err(vop_dev(vdev), "%s %d err %d\n",
862 __func__, __LINE__, err);
863 goto err;
864 }
865 err = _vop_virtio_copy(vdev, copy);
866 if (err) {
867 dev_err(vop_dev(vdev), "%s %d err %d\n",
868 __func__, __LINE__, err);
869 }
870err:
871 mutex_unlock(&vvr->vr_mutex);
872 return err;
873}
874
875static int vop_open(struct inode *inode, struct file *f)
876{
877 struct vop_vdev *vdev;
878 struct vop_info *vi = container_of(f->private_data,
879 struct vop_info, miscdev);
880
881 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
882 if (!vdev)
883 return -ENOMEM;
884 vdev->vi = vi;
885 mutex_init(&vdev->vdev_mutex);
886 f->private_data = vdev;
887 init_completion(&vdev->destroy);
888 complete(&vdev->destroy);
889 return 0;
890}
891
892static int vop_release(struct inode *inode, struct file *f)
893{
894 struct vop_vdev *vdev = f->private_data, *vdev_tmp;
895 struct vop_info *vi = vdev->vi;
896 struct list_head *pos, *tmp;
897 bool found = false;
898
899 mutex_lock(&vdev->vdev_mutex);
900 if (vdev->deleted)
901 goto unlock;
902 mutex_lock(&vi->vop_mutex);
903 list_for_each_safe(pos, tmp, &vi->vdev_list) {
904 vdev_tmp = list_entry(pos, struct vop_vdev, list);
905 if (vdev == vdev_tmp) {
906 vop_virtio_del_device(vdev);
907 list_del(pos);
908 found = true;
909 break;
910 }
911 }
912 mutex_unlock(&vi->vop_mutex);
913unlock:
914 mutex_unlock(&vdev->vdev_mutex);
915 if (!found)
916 wait_for_completion(&vdev->destroy);
917 f->private_data = NULL;
918 kfree(vdev);
919 return 0;
920}
921
922static long vop_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
923{
924 struct vop_vdev *vdev = f->private_data;
925 struct vop_info *vi = vdev->vi;
926 void __user *argp = (void __user *)arg;
927 int ret;
928
929 switch (cmd) {
930 case MIC_VIRTIO_ADD_DEVICE:
931 {
932 struct mic_device_desc dd, *dd_config;
933
934 if (copy_from_user(&dd, argp, sizeof(dd)))
935 return -EFAULT;
936
937 if (mic_aligned_desc_size(&dd) > MIC_MAX_DESC_BLK_SIZE ||
938 dd.num_vq > MIC_MAX_VRINGS)
939 return -EINVAL;
940
941 dd_config = kzalloc(mic_desc_size(&dd), GFP_KERNEL);
942 if (!dd_config)
943 return -ENOMEM;
944 if (copy_from_user(dd_config, argp, mic_desc_size(&dd))) {
945 ret = -EFAULT;
946 goto free_ret;
947 }
82dc4afd
AD		 948 /* Ensure desc has not changed between the two reads */
949 if (memcmp(&dd, dd_config, sizeof(dd))) {
950 ret = -EINVAL;
951 goto free_ret;
952 }
61e9c905
SD		 953 mutex_lock(&vdev->vdev_mutex);
954 mutex_lock(&vi->vop_mutex);
955 ret = vop_virtio_add_device(vdev, dd_config);
956 if (ret)
957 goto unlock_ret;
958 list_add_tail(&vdev->list, &vi->vdev_list);
959unlock_ret:
960 mutex_unlock(&vi->vop_mutex);
961 mutex_unlock(&vdev->vdev_mutex);
962free_ret:
963 kfree(dd_config);
964 return ret;
965 }
966 case MIC_VIRTIO_COPY_DESC:
967 {
968 struct mic_copy_desc copy;
969
970 mutex_lock(&vdev->vdev_mutex);
971 ret = vop_vdev_inited(vdev);
972 if (ret)
973 goto _unlock_ret;
974
975 if (copy_from_user(&copy, argp, sizeof(copy))) {
976 ret = -EFAULT;
977 goto _unlock_ret;
978 }
979
980 ret = vop_virtio_copy_desc(vdev, &copy);
981 if (ret < 0)
982 goto _unlock_ret;
983 if (copy_to_user(
984 &((struct mic_copy_desc __user *)argp)->out_len,
985 &copy.out_len, sizeof(copy.out_len)))
986 ret = -EFAULT;
987_unlock_ret:
988 mutex_unlock(&vdev->vdev_mutex);
989 return ret;
990 }
991 case MIC_VIRTIO_CONFIG_CHANGE:
992 {
993 void *buf;
994
995 mutex_lock(&vdev->vdev_mutex);
996 ret = vop_vdev_inited(vdev);
997 if (ret)
998 goto __unlock_ret;
999 buf = kzalloc(vdev->dd->config_len, GFP_KERNEL);
1000 if (!buf) {
1001 ret = -ENOMEM;
1002 goto __unlock_ret;
1003 }
1004 if (copy_from_user(buf, argp, vdev->dd->config_len)) {
1005 ret = -EFAULT;
1006 goto done;
1007 }
1008 ret = vop_virtio_config_change(vdev, buf);
1009done:
1010 kfree(buf);
1011__unlock_ret:
1012 mutex_unlock(&vdev->vdev_mutex);
1013 return ret;
1014 }
1015 default:
1016 return -ENOIOCTLCMD;
1017 };
1018 return 0;
1019}
1020
1021/*
1022 * We return POLLIN | POLLOUT from poll when new buffers are enqueued, and
1023 * not when previously enqueued buffers may be available. This means that
1024 * in the card->host (TX) path, when userspace is unblocked by poll it
1025 * must drain all available descriptors or it can stall.
1026 */
1027static unsigned int vop_poll(struct file *f, poll_table *wait)
1028{
1029 struct vop_vdev *vdev = f->private_data;
1030 int mask = 0;
1031
1032 mutex_lock(&vdev->vdev_mutex);
1033 if (vop_vdev_inited(vdev)) {
1034 mask = POLLERR;
1035 goto done;
1036 }
1037 poll_wait(f, &vdev->waitq, wait);
1038 if (vop_vdev_inited(vdev)) {
1039 mask = POLLERR;
1040 } else if (vdev->poll_wake) {
1041 vdev->poll_wake = 0;
1042 mask = POLLIN | POLLOUT;
1043 }
1044done:
1045 mutex_unlock(&vdev->vdev_mutex);
1046 return mask;
1047}
1048
1049static inline int
1050vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
1051 unsigned long *size, unsigned long *pa)
1052{
1053 struct vop_device *vpdev = vdev->vpdev;
1054 unsigned long start = MIC_DP_SIZE;
1055 int i;
1056
1057 /*
1058 * MMAP interface is as follows:
1059 * offset region
1060 * 0x0 virtio device_page
1061 * 0x1000 first vring
1062 * 0x1000 + size of 1st vring second vring
1063 * ....
1064 */
1065 if (!offset) {
1066 *pa = virt_to_phys(vpdev->hw_ops->get_dp(vpdev));
1067 *size = MIC_DP_SIZE;
1068 return 0;
1069 }
1070
1071 for (i = 0; i < vdev->dd->num_vq; i++) {
1072 struct vop_vringh *vvr = &vdev->vvr[i];
1073
1074 if (offset == start) {
1075 *pa = virt_to_phys(vvr->vring.va);
1076 *size = vvr->vring.len;
1077 return 0;
1078 }
1079 start += vvr->vring.len;
1080 }
1081 return -1;
1082}
1083
1084/*
1085 * Maps the device page and virtio rings to user space for readonly access.
1086 */
1087static int vop_mmap(struct file *f, struct vm_area_struct *vma)
1088{
1089 struct vop_vdev *vdev = f->private_data;
1090 unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
1091 unsigned long pa, size = vma->vm_end - vma->vm_start, size_rem = size;
1092 int i, err;
1093
1094 err = vop_vdev_inited(vdev);
1095 if (err)
1096 goto ret;
1097 if (vma->vm_flags & VM_WRITE) {
1098 err = -EACCES;
1099 goto ret;
1100 }
1101 while (size_rem) {
1102 i = vop_query_offset(vdev, offset, &size, &pa);
1103 if (i < 0) {
1104 err = -EINVAL;
1105 goto ret;
1106 }
1107 err = remap_pfn_range(vma, vma->vm_start + offset,
1108 pa >> PAGE_SHIFT, size,
1109 vma->vm_page_prot);
1110 if (err)
1111 goto ret;
1112 size_rem -= size;
1113 offset += size;
1114 }
1115ret:
1116 return err;
1117}
1118
1119static const struct file_operations vop_fops = {
1120 .open = vop_open,
1121 .release = vop_release,
1122 .unlocked_ioctl = vop_ioctl,
1123 .poll = vop_poll,
1124 .mmap = vop_mmap,
1125 .owner = THIS_MODULE,
1126};
1127
1128int vop_host_init(struct vop_info *vi)
1129{
1130 int rc;
1131 struct miscdevice *mdev;
1132 struct vop_device *vpdev = vi->vpdev;
1133
1134 INIT_LIST_HEAD(&vi->vdev_list);
1135 vi->dma_ch = vpdev->dma_ch;
1136 mdev = &vi->miscdev;
1137 mdev->minor = MISC_DYNAMIC_MINOR;
1138 snprintf(vi->name, sizeof(vi->name), "vop_virtio%d", vpdev->index);
1139 mdev->name = vi->name;
1140 mdev->fops = &vop_fops;
1141 mdev->parent = &vpdev->dev;
1142
1143 rc = misc_register(mdev);
1144 if (rc)
1145 dev_err(&vpdev->dev, "%s failed rc %d\n", __func__, rc);
1146 return rc;
1147}
1148
1149void vop_host_uninit(struct vop_info *vi)
1150{
1151 struct list_head *pos, *tmp;
1152 struct vop_vdev *vdev;
1153
1154 mutex_lock(&vi->vop_mutex);
1155 vop_virtio_reset_devices(vi);
1156 list_for_each_safe(pos, tmp, &vi->vdev_list) {
1157 vdev = list_entry(pos, struct vop_vdev, list);
1158 list_del(pos);
1159 reinit_completion(&vdev->destroy);
1160 mutex_unlock(&vi->vop_mutex);
1161 mutex_lock(&vdev->vdev_mutex);
1162 vop_virtio_del_device(vdev);
1163 vdev->deleted = true;
1164 mutex_unlock(&vdev->vdev_mutex);
1165 complete(&vdev->destroy);
1166 mutex_lock(&vi->vop_mutex);
1167 }
1168 mutex_unlock(&vi->vop_mutex);
1169 misc_deregister(&vi->miscdev);
1170}
Linux kernel - Deliverables
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