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gerrit-public.fairphone.software / kernel / msm-5.4 / 84cd8fc48478b5e67b3f1600717299e11430a67e / . / drivers / s390 / cio / vfio_ccw_ops.c
blob: b8a2fed58f02938ff8e0cca2b2aba7325f93f6a5 [file] [log] [blame]
Dong Jia Shi84cd8fc2017-03-17 04:17:33 +0100[diff] [blame^]1/*
2 * Physical device callbacks for vfio_ccw
3 *
4 * Copyright IBM Corp. 2017
5 *
6 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
7 * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
8 */
9
10#include <linux/vfio.h>
11#include <linux/mdev.h>
12
13#include "vfio_ccw_private.h"
14
15static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
16 unsigned long action,
17 void *data)
18{
19 struct vfio_ccw_private *private =
20 container_of(nb, struct vfio_ccw_private, nb);
21
22 if (!private)
23 return NOTIFY_STOP;
24
25 /*
26 * TODO:
27 * Vendor drivers MUST unpin pages in response to an
28 * invalidation.
29 */
30 if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP)
31 return NOTIFY_BAD;
32
33 return NOTIFY_DONE;
34}
35
36static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
37{
38 return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
39}
40MDEV_TYPE_ATTR_RO(name);
41
42static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
43 char *buf)
44{
45 return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
46}
47MDEV_TYPE_ATTR_RO(device_api);
48
49static ssize_t available_instances_show(struct kobject *kobj,
50 struct device *dev, char *buf)
51{
52 struct vfio_ccw_private *private = dev_get_drvdata(dev);
53
54 return sprintf(buf, "%d\n", atomic_read(&private->avail));
55}
56MDEV_TYPE_ATTR_RO(available_instances);
57
58static struct attribute *mdev_types_attrs[] = {
59 &mdev_type_attr_name.attr,
60 &mdev_type_attr_device_api.attr,
61 &mdev_type_attr_available_instances.attr,
62 NULL,
63};
64
65static struct attribute_group mdev_type_group = {
66 .name = "io",
67 .attrs = mdev_types_attrs,
68};
69
70struct attribute_group *mdev_type_groups[] = {
71 &mdev_type_group,
72 NULL,
73};
74
75static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
76{
77 struct vfio_ccw_private *private =
78 dev_get_drvdata(mdev_parent_dev(mdev));
79
80 if (atomic_dec_if_positive(&private->avail) < 0)
81 return -EPERM;
82
83 private->mdev = mdev;
84
85 return 0;
86}
87
88static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
89{
90 struct vfio_ccw_private *private;
91 struct subchannel *sch;
92 int ret;
93
94 private = dev_get_drvdata(mdev_parent_dev(mdev));
95 sch = private->sch;
96 ret = vfio_ccw_sch_quiesce(sch);
97 if (ret)
98 return ret;
99 ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
100 if (ret)
101 return ret;
102
103 private->mdev = NULL;
104 atomic_inc(&private->avail);
105
106 return 0;
107}
108
109static int vfio_ccw_mdev_open(struct mdev_device *mdev)
110{
111 struct vfio_ccw_private *private =
112 dev_get_drvdata(mdev_parent_dev(mdev));
113 unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
114
115 private->nb.notifier_call = vfio_ccw_mdev_notifier;
116
117 return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
118 &events, &private->nb);
119}
120
121void vfio_ccw_mdev_release(struct mdev_device *mdev)
122{
123 struct vfio_ccw_private *private =
124 dev_get_drvdata(mdev_parent_dev(mdev));
125
126 vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
127 &private->nb);
128}
129
130static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
131 .owner = THIS_MODULE,
132 .supported_type_groups = mdev_type_groups,
133 .create = vfio_ccw_mdev_create,
134 .remove = vfio_ccw_mdev_remove,
135 .open = vfio_ccw_mdev_open,
136 .release = vfio_ccw_mdev_release,
137};
138
139int vfio_ccw_mdev_reg(struct subchannel *sch)
140{
141 return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
142}
143
144void vfio_ccw_mdev_unreg(struct subchannel *sch)
145{
146 mdev_unregister_device(&sch->dev);
147}