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 struct subchannel *sch = to_subchannel(private->vdev.dev->parent);
20 unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
21 loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
22 struct ccw_schib_region *region;
23 int ret;
24
25 if (pos + count > sizeof(*region))
26 return -EINVAL;
27
28 mutex_lock(&private->io_mutex);
29 region = private->region[i].data;
30
31 if (cio_update_schib(sch)) {
32 ret = -ENODEV;
33 goto out;
34 }
35
36 memcpy(region, &sch->schib, sizeof(*region));
37
38 if (copy_to_user(buf, (void *)region + pos, count)) {
39 ret = -EFAULT;
40 goto out;
41 }
42
43 ret = count;
44
45 out:
46 mutex_unlock(&private->io_mutex);
47 return ret;
48 }
49
vfio_ccw_schib_region_write(struct vfio_ccw_private * private,const char __user * buf,size_t count,loff_t * ppos)50 static ssize_t vfio_ccw_schib_region_write(struct vfio_ccw_private *private,
51 const char __user *buf, size_t count,
52 loff_t *ppos)
53 {
54 return -EINVAL;
55 }
56
57
vfio_ccw_schib_region_release(struct vfio_ccw_private * private,struct vfio_ccw_region * region)58 static void vfio_ccw_schib_region_release(struct vfio_ccw_private *private,
59 struct vfio_ccw_region *region)
60 {
61
62 }
63
64 static const struct vfio_ccw_regops vfio_ccw_schib_region_ops = {
65 .read = vfio_ccw_schib_region_read,
66 .write = vfio_ccw_schib_region_write,
67 .release = vfio_ccw_schib_region_release,
68 };
69
vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private * private)70 int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private)
71 {
72 return vfio_ccw_register_dev_region(private,
73 VFIO_REGION_SUBTYPE_CCW_SCHIB,
74 &vfio_ccw_schib_region_ops,
75 sizeof(struct ccw_schib_region),
76 VFIO_REGION_INFO_FLAG_READ,
77 private->schib_region);
78 }
79
vfio_ccw_crw_region_read(struct vfio_ccw_private * private,char __user * buf,size_t count,loff_t * ppos)80 static ssize_t vfio_ccw_crw_region_read(struct vfio_ccw_private *private,
81 char __user *buf, size_t count,
82 loff_t *ppos)
83 {
84 unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
85 loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
86 struct ccw_crw_region *region;
87 struct vfio_ccw_crw *crw;
88 int ret;
89
90 if (pos + count > sizeof(*region))
91 return -EINVAL;
92
93 crw = list_first_entry_or_null(&private->crw,
94 struct vfio_ccw_crw, next);
95
96 if (crw)
97 list_del(&crw->next);
98
99 mutex_lock(&private->io_mutex);
100 region = private->region[i].data;
101
102 if (crw)
103 memcpy(®ion->crw, &crw->crw, sizeof(region->crw));
104
105 if (copy_to_user(buf, (void *)region + pos, count))
106 ret = -EFAULT;
107 else
108 ret = count;
109
110 region->crw = 0;
111
112 mutex_unlock(&private->io_mutex);
113
114 kfree(crw);
115
116 /* Notify the guest if more CRWs are on our queue */
117 if (!list_empty(&private->crw) && private->crw_trigger)
118 eventfd_signal(private->crw_trigger, 1);
119
120 return ret;
121 }
122
vfio_ccw_crw_region_write(struct vfio_ccw_private * private,const char __user * buf,size_t count,loff_t * ppos)123 static ssize_t vfio_ccw_crw_region_write(struct vfio_ccw_private *private,
124 const char __user *buf, size_t count,
125 loff_t *ppos)
126 {
127 return -EINVAL;
128 }
129
vfio_ccw_crw_region_release(struct vfio_ccw_private * private,struct vfio_ccw_region * region)130 static void vfio_ccw_crw_region_release(struct vfio_ccw_private *private,
131 struct vfio_ccw_region *region)
132 {
133
134 }
135
136 static const struct vfio_ccw_regops vfio_ccw_crw_region_ops = {
137 .read = vfio_ccw_crw_region_read,
138 .write = vfio_ccw_crw_region_write,
139 .release = vfio_ccw_crw_region_release,
140 };
141
vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private * private)142 int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private)
143 {
144 return vfio_ccw_register_dev_region(private,
145 VFIO_REGION_SUBTYPE_CCW_CRW,
146 &vfio_ccw_crw_region_ops,
147 sizeof(struct ccw_crw_region),
148 VFIO_REGION_INFO_FLAG_READ,
149 private->crw_region);
150 }
151