1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Async I/O region for vfio_ccw
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright Red Hat, Inc. 2019
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Author(s): Cornelia Huck <cohuck@redhat.com>
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/vfio.h>
11*4882a593Smuzhiyun #include <linux/mdev.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include "vfio_ccw_private.h"
14*4882a593Smuzhiyun
vfio_ccw_async_region_read(struct vfio_ccw_private * private,char __user * buf,size_t count,loff_t * ppos)15*4882a593Smuzhiyun static ssize_t vfio_ccw_async_region_read(struct vfio_ccw_private *private,
16*4882a593Smuzhiyun char __user *buf, size_t count,
17*4882a593Smuzhiyun loff_t *ppos)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
20*4882a593Smuzhiyun loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
21*4882a593Smuzhiyun struct ccw_cmd_region *region;
22*4882a593Smuzhiyun int ret;
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun if (pos + count > sizeof(*region))
25*4882a593Smuzhiyun return -EINVAL;
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun mutex_lock(&private->io_mutex);
28*4882a593Smuzhiyun region = private->region[i].data;
29*4882a593Smuzhiyun if (copy_to_user(buf, (void *)region + pos, count))
30*4882a593Smuzhiyun ret = -EFAULT;
31*4882a593Smuzhiyun else
32*4882a593Smuzhiyun ret = count;
33*4882a593Smuzhiyun mutex_unlock(&private->io_mutex);
34*4882a593Smuzhiyun return ret;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
vfio_ccw_async_region_write(struct vfio_ccw_private * private,const char __user * buf,size_t count,loff_t * ppos)37*4882a593Smuzhiyun static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private,
38*4882a593Smuzhiyun const char __user *buf, size_t count,
39*4882a593Smuzhiyun loff_t *ppos)
40*4882a593Smuzhiyun {
41*4882a593Smuzhiyun unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
42*4882a593Smuzhiyun loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
43*4882a593Smuzhiyun struct ccw_cmd_region *region;
44*4882a593Smuzhiyun int ret;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun if (pos + count > sizeof(*region))
47*4882a593Smuzhiyun return -EINVAL;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun if (!mutex_trylock(&private->io_mutex))
50*4882a593Smuzhiyun return -EAGAIN;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun region = private->region[i].data;
53*4882a593Smuzhiyun if (copy_from_user((void *)region + pos, buf, count)) {
54*4882a593Smuzhiyun ret = -EFAULT;
55*4882a593Smuzhiyun goto out_unlock;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_ASYNC_REQ);
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun ret = region->ret_code ? region->ret_code : count;
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun out_unlock:
63*4882a593Smuzhiyun mutex_unlock(&private->io_mutex);
64*4882a593Smuzhiyun return ret;
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun
vfio_ccw_async_region_release(struct vfio_ccw_private * private,struct vfio_ccw_region * region)67*4882a593Smuzhiyun static void vfio_ccw_async_region_release(struct vfio_ccw_private *private,
68*4882a593Smuzhiyun struct vfio_ccw_region *region)
69*4882a593Smuzhiyun {
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun static const struct vfio_ccw_regops vfio_ccw_async_region_ops = {
74*4882a593Smuzhiyun .read = vfio_ccw_async_region_read,
75*4882a593Smuzhiyun .write = vfio_ccw_async_region_write,
76*4882a593Smuzhiyun .release = vfio_ccw_async_region_release,
77*4882a593Smuzhiyun };
78*4882a593Smuzhiyun
vfio_ccw_register_async_dev_regions(struct vfio_ccw_private * private)79*4882a593Smuzhiyun int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private)
80*4882a593Smuzhiyun {
81*4882a593Smuzhiyun return vfio_ccw_register_dev_region(private,
82*4882a593Smuzhiyun VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD,
83*4882a593Smuzhiyun &vfio_ccw_async_region_ops,
84*4882a593Smuzhiyun sizeof(struct ccw_cmd_region),
85*4882a593Smuzhiyun VFIO_REGION_INFO_FLAG_READ |
86*4882a593Smuzhiyun VFIO_REGION_INFO_FLAG_WRITE,
87*4882a593Smuzhiyun private->cmd_region);
88*4882a593Smuzhiyun }
89