1d5afd5d1SCornelia Huck // SPDX-License-Identifier: GPL-2.0
2d5afd5d1SCornelia Huck /*
3d5afd5d1SCornelia Huck * Async I/O region for vfio_ccw
4d5afd5d1SCornelia Huck *
5d5afd5d1SCornelia Huck * Copyright Red Hat, Inc. 2019
6d5afd5d1SCornelia Huck *
7d5afd5d1SCornelia Huck * Author(s): Cornelia Huck <cohuck@redhat.com>
8d5afd5d1SCornelia Huck */
9d5afd5d1SCornelia Huck
10d5afd5d1SCornelia Huck #include <linux/vfio.h>
11d5afd5d1SCornelia Huck
12d5afd5d1SCornelia Huck #include "vfio_ccw_private.h"
13d5afd5d1SCornelia Huck
vfio_ccw_async_region_read(struct vfio_ccw_private * private,char __user * buf,size_t count,loff_t * ppos)14d5afd5d1SCornelia Huck static ssize_t vfio_ccw_async_region_read(struct vfio_ccw_private *private,
15d5afd5d1SCornelia Huck char __user *buf, size_t count,
16d5afd5d1SCornelia Huck loff_t *ppos)
17d5afd5d1SCornelia Huck {
18d5afd5d1SCornelia Huck unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
19d5afd5d1SCornelia Huck loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
20d5afd5d1SCornelia Huck struct ccw_cmd_region *region;
21d5afd5d1SCornelia Huck int ret;
22d5afd5d1SCornelia Huck
23d5afd5d1SCornelia Huck if (pos + count > sizeof(*region))
24d5afd5d1SCornelia Huck return -EINVAL;
25d5afd5d1SCornelia Huck
26d5afd5d1SCornelia Huck mutex_lock(&private->io_mutex);
27d5afd5d1SCornelia Huck region = private->region[i].data;
28d5afd5d1SCornelia Huck if (copy_to_user(buf, (void *)region + pos, count))
29d5afd5d1SCornelia Huck ret = -EFAULT;
30d5afd5d1SCornelia Huck else
31d5afd5d1SCornelia Huck ret = count;
32d5afd5d1SCornelia Huck mutex_unlock(&private->io_mutex);
33d5afd5d1SCornelia Huck return ret;
34d5afd5d1SCornelia Huck }
35d5afd5d1SCornelia Huck
vfio_ccw_async_region_write(struct vfio_ccw_private * private,const char __user * buf,size_t count,loff_t * ppos)36d5afd5d1SCornelia Huck static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private,
37d5afd5d1SCornelia Huck const char __user *buf, size_t count,
38d5afd5d1SCornelia Huck loff_t *ppos)
39d5afd5d1SCornelia Huck {
40d5afd5d1SCornelia Huck unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
41d5afd5d1SCornelia Huck loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
42d5afd5d1SCornelia Huck struct ccw_cmd_region *region;
43d5afd5d1SCornelia Huck int ret;
44d5afd5d1SCornelia Huck
45d5afd5d1SCornelia Huck if (pos + count > sizeof(*region))
46d5afd5d1SCornelia Huck return -EINVAL;
47d5afd5d1SCornelia Huck
48d5afd5d1SCornelia Huck if (!mutex_trylock(&private->io_mutex))
49d5afd5d1SCornelia Huck return -EAGAIN;
50d5afd5d1SCornelia Huck
51d5afd5d1SCornelia Huck region = private->region[i].data;
52d5afd5d1SCornelia Huck if (copy_from_user((void *)region + pos, buf, count)) {
53d5afd5d1SCornelia Huck ret = -EFAULT;
54d5afd5d1SCornelia Huck goto out_unlock;
55d5afd5d1SCornelia Huck }
56d5afd5d1SCornelia Huck
57d5afd5d1SCornelia Huck vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_ASYNC_REQ);
58d5afd5d1SCornelia Huck
59d5afd5d1SCornelia Huck ret = region->ret_code ? region->ret_code : count;
60d5afd5d1SCornelia Huck
61d5afd5d1SCornelia Huck out_unlock:
62d5afd5d1SCornelia Huck mutex_unlock(&private->io_mutex);
63d5afd5d1SCornelia Huck return ret;
64d5afd5d1SCornelia Huck }
65d5afd5d1SCornelia Huck
vfio_ccw_async_region_release(struct vfio_ccw_private * private,struct vfio_ccw_region * region)66d5afd5d1SCornelia Huck static void vfio_ccw_async_region_release(struct vfio_ccw_private *private,
67d5afd5d1SCornelia Huck struct vfio_ccw_region *region)
68d5afd5d1SCornelia Huck {
69d5afd5d1SCornelia Huck
70d5afd5d1SCornelia Huck }
71d5afd5d1SCornelia Huck
7284806572SVasily Gorbik static const struct vfio_ccw_regops vfio_ccw_async_region_ops = {
73d5afd5d1SCornelia Huck .read = vfio_ccw_async_region_read,
74d5afd5d1SCornelia Huck .write = vfio_ccw_async_region_write,
75d5afd5d1SCornelia Huck .release = vfio_ccw_async_region_release,
76d5afd5d1SCornelia Huck };
77d5afd5d1SCornelia Huck
vfio_ccw_register_async_dev_regions(struct vfio_ccw_private * private)78d5afd5d1SCornelia Huck int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private)
79d5afd5d1SCornelia Huck {
80d5afd5d1SCornelia Huck return vfio_ccw_register_dev_region(private,
81d5afd5d1SCornelia Huck VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD,
82d5afd5d1SCornelia Huck &vfio_ccw_async_region_ops,
83d5afd5d1SCornelia Huck sizeof(struct ccw_cmd_region),
84d5afd5d1SCornelia Huck VFIO_REGION_INFO_FLAG_READ |
85d5afd5d1SCornelia Huck VFIO_REGION_INFO_FLAG_WRITE,
86d5afd5d1SCornelia Huck private->cmd_region);
87d5afd5d1SCornelia Huck }
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