1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Channel path related status regions for vfio_ccw
4 *
5 * Copyright IBM Corp. 2020
6 *
7 * Author(s): Farhan Ali <alifm@linux.ibm.com>
8 * Eric Farman <farman@linux.ibm.com>
9 */
10
11 #include <linux/slab.h>
12 #include <linux/vfio.h>
13 #include "vfio_ccw_private.h"
14
vfio_ccw_schib_region_read(struct vfio_ccw_private * private,char __user * buf,size_t count,loff_t * ppos)15 static ssize_t vfio_ccw_schib_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_schib_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
30 if (cio_update_schib(private->sch)) {
31 ret = -ENODEV;
32 goto out;
33 }
34
35 memcpy(region, &private->sch->schib, sizeof(*region));
36
37 if (copy_to_user(buf, (void *)region + pos, count)) {
38 ret = -EFAULT;
39 goto out;
40 }
41
42 ret = count;
43
44 out:
45 mutex_unlock(&private->io_mutex);
46 return ret;
47 }
48
vfio_ccw_schib_region_write(struct vfio_ccw_private * private,const char __user * buf,size_t count,loff_t * ppos)49 static ssize_t vfio_ccw_schib_region_write(struct vfio_ccw_private *private,
50 const char __user *buf, size_t count,
51 loff_t *ppos)
52 {
53 return -EINVAL;
54 }
55
56
vfio_ccw_schib_region_release(struct vfio_ccw_private * private,struct vfio_ccw_region * region)57 static void vfio_ccw_schib_region_release(struct vfio_ccw_private *private,
58 struct vfio_ccw_region *region)
59 {
60
61 }
62
63 static const struct vfio_ccw_regops vfio_ccw_schib_region_ops = {
64 .read = vfio_ccw_schib_region_read,
65 .write = vfio_ccw_schib_region_write,
66 .release = vfio_ccw_schib_region_release,
67 };
68
vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private * private)69 int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private)
70 {
71 return vfio_ccw_register_dev_region(private,
72 VFIO_REGION_SUBTYPE_CCW_SCHIB,
73 &vfio_ccw_schib_region_ops,
74 sizeof(struct ccw_schib_region),
75 VFIO_REGION_INFO_FLAG_READ,
76 private->schib_region);
77 }
78
vfio_ccw_crw_region_read(struct vfio_ccw_private * private,char __user * buf,size_t count,loff_t * ppos)79 static ssize_t vfio_ccw_crw_region_read(struct vfio_ccw_private *private,
80 char __user *buf, size_t count,
81 loff_t *ppos)
82 {
83 unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
84 loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
85 struct ccw_crw_region *region;
86 struct vfio_ccw_crw *crw;
87 int ret;
88
89 if (pos + count > sizeof(*region))
90 return -EINVAL;
91
92 crw = list_first_entry_or_null(&private->crw,
93 struct vfio_ccw_crw, next);
94
95 if (crw)
96 list_del(&crw->next);
97
98 mutex_lock(&private->io_mutex);
99 region = private->region[i].data;
100
101 if (crw)
102 memcpy(®ion->crw, &crw->crw, sizeof(region->crw));
103
104 if (copy_to_user(buf, (void *)region + pos, count))
105 ret = -EFAULT;
106 else
107 ret = count;
108
109 region->crw = 0;
110
111 mutex_unlock(&private->io_mutex);
112
113 kfree(crw);
114
115 /* Notify the guest if more CRWs are on our queue */
116 if (!list_empty(&private->crw) && private->crw_trigger)
117 eventfd_signal(private->crw_trigger, 1);
118
119 return ret;
120 }
121
vfio_ccw_crw_region_write(struct vfio_ccw_private * private,const char __user * buf,size_t count,loff_t * ppos)122 static ssize_t vfio_ccw_crw_region_write(struct vfio_ccw_private *private,
123 const char __user *buf, size_t count,
124 loff_t *ppos)
125 {
126 return -EINVAL;
127 }
128
vfio_ccw_crw_region_release(struct vfio_ccw_private * private,struct vfio_ccw_region * region)129 static void vfio_ccw_crw_region_release(struct vfio_ccw_private *private,
130 struct vfio_ccw_region *region)
131 {
132
133 }
134
135 static const struct vfio_ccw_regops vfio_ccw_crw_region_ops = {
136 .read = vfio_ccw_crw_region_read,
137 .write = vfio_ccw_crw_region_write,
138 .release = vfio_ccw_crw_region_release,
139 };
140
vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private * private)141 int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private)
142 {
143 return vfio_ccw_register_dev_region(private,
144 VFIO_REGION_SUBTYPE_CCW_CRW,
145 &vfio_ccw_crw_region_ops,
146 sizeof(struct ccw_crw_region),
147 VFIO_REGION_INFO_FLAG_READ,
148 private->crw_region);
149 }
150