1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Async I/O region for vfio_ccw
 4 *
 5 * Copyright Red Hat, Inc. 2019
 6 *
 7 * Author(s): Cornelia Huck <cohuck@redhat.com>
 8 */
 9
10#include <linux/vfio.h>
 
11
12#include "vfio_ccw_private.h"
13
14static ssize_t vfio_ccw_async_region_read(struct vfio_ccw_private *private,
15					  char __user *buf, size_t count,
16					  loff_t *ppos)
17{
18	unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
19	loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
20	struct ccw_cmd_region *region;
21	int ret;
22
23	if (pos + count > sizeof(*region))
24		return -EINVAL;
25
26	mutex_lock(&private->io_mutex);
27	region = private->region[i].data;
28	if (copy_to_user(buf, (void *)region + pos, count))
29		ret = -EFAULT;
30	else
31		ret = count;
32	mutex_unlock(&private->io_mutex);
33	return ret;
34}
35
36static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private,
37					   const char __user *buf, size_t count,
38					   loff_t *ppos)
39{
40	unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
41	loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
42	struct ccw_cmd_region *region;
43	int ret;
44
45	if (pos + count > sizeof(*region))
46		return -EINVAL;
47
48	if (!mutex_trylock(&private->io_mutex))
49		return -EAGAIN;
50
51	region = private->region[i].data;
52	if (copy_from_user((void *)region + pos, buf, count)) {
53		ret = -EFAULT;
54		goto out_unlock;
55	}
56
57	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_ASYNC_REQ);
58
59	ret = region->ret_code ? region->ret_code : count;
60
61out_unlock:
62	mutex_unlock(&private->io_mutex);
63	return ret;
64}
65
66static void vfio_ccw_async_region_release(struct vfio_ccw_private *private,
67					  struct vfio_ccw_region *region)
68{
69
70}
71
72static const struct vfio_ccw_regops vfio_ccw_async_region_ops = {
73	.read = vfio_ccw_async_region_read,
74	.write = vfio_ccw_async_region_write,
75	.release = vfio_ccw_async_region_release,
76};
77
78int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private)
79{
80	return vfio_ccw_register_dev_region(private,
81					    VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD,
82					    &vfio_ccw_async_region_ops,
83					    sizeof(struct ccw_cmd_region),
84					    VFIO_REGION_INFO_FLAG_READ |
85					    VFIO_REGION_INFO_FLAG_WRITE,
86					    private->cmd_region);
87}

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Async I/O region for vfio_ccw
 4 *
 5 * Copyright Red Hat, Inc. 2019
 6 *
 7 * Author(s): Cornelia Huck <cohuck@redhat.com>
 8 */
 9
10#include <linux/vfio.h>
11#include <linux/mdev.h>
12
13#include "vfio_ccw_private.h"
14
15static ssize_t vfio_ccw_async_region_read(struct vfio_ccw_private *private,
16					  char __user *buf, size_t count,
17					  loff_t *ppos)
18{
19	unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
20	loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
21	struct ccw_cmd_region *region;
22	int ret;
23
24	if (pos + count > sizeof(*region))
25		return -EINVAL;
26
27	mutex_lock(&private->io_mutex);
28	region = private->region[i].data;
29	if (copy_to_user(buf, (void *)region + pos, count))
30		ret = -EFAULT;
31	else
32		ret = count;
33	mutex_unlock(&private->io_mutex);
34	return ret;
35}
36
37static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private,
38					   const char __user *buf, size_t count,
39					   loff_t *ppos)
40{
41	unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
42	loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
43	struct ccw_cmd_region *region;
44	int ret;
45
46	if (pos + count > sizeof(*region))
47		return -EINVAL;
48
49	if (!mutex_trylock(&private->io_mutex))
50		return -EAGAIN;
51
52	region = private->region[i].data;
53	if (copy_from_user((void *)region + pos, buf, count)) {
54		ret = -EFAULT;
55		goto out_unlock;
56	}
57
58	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_ASYNC_REQ);
59
60	ret = region->ret_code ? region->ret_code : count;
61
62out_unlock:
63	mutex_unlock(&private->io_mutex);
64	return ret;
65}
66
67static void vfio_ccw_async_region_release(struct vfio_ccw_private *private,
68					  struct vfio_ccw_region *region)
69{
70
71}
72
73static const struct vfio_ccw_regops vfio_ccw_async_region_ops = {
74	.read = vfio_ccw_async_region_read,
75	.write = vfio_ccw_async_region_write,
76	.release = vfio_ccw_async_region_release,
77};
78
79int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private)
80{
81	return vfio_ccw_register_dev_region(private,
82					    VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD,
83					    &vfio_ccw_async_region_ops,
84					    sizeof(struct ccw_cmd_region),
85					    VFIO_REGION_INFO_FLAG_READ |
86					    VFIO_REGION_INFO_FLAG_WRITE,
87					    private->cmd_region);
88}