tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * VFIO based AP device driver
4 *
5 * Copyright IBM Corp. 2018
6 *
7 * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
8 * Pierre Morel <pmorel@linux.ibm.com>
9 */
10
11#include <linux/module.h>
12#include <linux/mod_devicetable.h>
13#include <linux/slab.h>
14#include <linux/string.h>
15#include <asm/facility.h>
16#include "vfio_ap_private.h"
17
18#define VFIO_AP_ROOT_NAME "vfio_ap"
19#define VFIO_AP_DEV_NAME "matrix"
20
21MODULE_AUTHOR("IBM Corporation");
22MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
23MODULE_LICENSE("GPL v2");
24
25struct ap_matrix_dev *matrix_dev;
26
27/* Only type 10 adapters (CEX4 and later) are supported
28 * by the AP matrix device driver
29 */
30static struct ap_device_id ap_queue_ids[] = {
31 { .dev_type = AP_DEVICE_TYPE_CEX4,
32 .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
33 { .dev_type = AP_DEVICE_TYPE_CEX5,
34 .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
35 { .dev_type = AP_DEVICE_TYPE_CEX6,
36 .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
37 { .dev_type = AP_DEVICE_TYPE_CEX7,
38 .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
39 { /* end of sibling */ },
40};
41
42MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
43
44/**
45 * vfio_ap_queue_dev_probe:
46 *
47 * Allocate a vfio_ap_queue structure and associate it
48 * with the device as driver_data.
49 */
50static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
51{
52 struct vfio_ap_queue *q;
53
54 q = kzalloc(sizeof(*q), GFP_KERNEL);
55 if (!q)
56 return -ENOMEM;
57 dev_set_drvdata(&apdev->device, q);
58 q->apqn = to_ap_queue(&apdev->device)->qid;
59 q->saved_isc = VFIO_AP_ISC_INVALID;
60 return 0;
61}
62
63/**
64 * vfio_ap_queue_dev_remove:
65 *
66 * Takes the matrix lock to avoid actions on this device while removing
67 * Free the associated vfio_ap_queue structure
68 */
69static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
70{
71 struct vfio_ap_queue *q;
72
73 mutex_lock(&matrix_dev->lock);
74 q = dev_get_drvdata(&apdev->device);
75 vfio_ap_mdev_reset_queue(q, 1);
76 dev_set_drvdata(&apdev->device, NULL);
77 kfree(q);
78 mutex_unlock(&matrix_dev->lock);
79}
80
81static struct ap_driver vfio_ap_drv = {
82 .probe = vfio_ap_queue_dev_probe,
83 .remove = vfio_ap_queue_dev_remove,
84 .ids = ap_queue_ids,
85};
86
87static void vfio_ap_matrix_dev_release(struct device *dev)
88{
89 struct ap_matrix_dev *matrix_dev = dev_get_drvdata(dev);
90
91 kfree(matrix_dev);
92}
93
94static int matrix_bus_match(struct device *dev, struct device_driver *drv)
95{
96 return 1;
97}
98
99static struct bus_type matrix_bus = {
100 .name = "matrix",
101 .match = &matrix_bus_match,
102};
103
104static struct device_driver matrix_driver = {
105 .name = "vfio_ap",
106 .bus = &matrix_bus,
107 .suppress_bind_attrs = true,
108};
109
110static int vfio_ap_matrix_dev_create(void)
111{
112 int ret;
113 struct device *root_device;
114
115 root_device = root_device_register(VFIO_AP_ROOT_NAME);
116 if (IS_ERR(root_device))
117 return PTR_ERR(root_device);
118
119 ret = bus_register(&matrix_bus);
120 if (ret)
121 goto bus_register_err;
122
123 matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
124 if (!matrix_dev) {
125 ret = -ENOMEM;
126 goto matrix_alloc_err;
127 }
128
129 /* Fill in config info via PQAP(QCI), if available */
130 if (test_facility(12)) {
131 ret = ap_qci(&matrix_dev->info);
132 if (ret)
133 goto matrix_alloc_err;
134 }
135
136 mutex_init(&matrix_dev->lock);
137 INIT_LIST_HEAD(&matrix_dev->mdev_list);
138
139 dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
140 matrix_dev->device.parent = root_device;
141 matrix_dev->device.bus = &matrix_bus;
142 matrix_dev->device.release = vfio_ap_matrix_dev_release;
143 matrix_dev->vfio_ap_drv = &vfio_ap_drv;
144
145 ret = device_register(&matrix_dev->device);
146 if (ret)
147 goto matrix_reg_err;
148
149 ret = driver_register(&matrix_driver);
150 if (ret)
151 goto matrix_drv_err;
152
153 return 0;
154
155matrix_drv_err:
156 device_unregister(&matrix_dev->device);
157matrix_reg_err:
158 put_device(&matrix_dev->device);
159matrix_alloc_err:
160 bus_unregister(&matrix_bus);
161bus_register_err:
162 root_device_unregister(root_device);
163 return ret;
164}
165
166static void vfio_ap_matrix_dev_destroy(void)
167{
168 struct device *root_device = matrix_dev->device.parent;
169
170 driver_unregister(&matrix_driver);
171 device_unregister(&matrix_dev->device);
172 bus_unregister(&matrix_bus);
173 root_device_unregister(root_device);
174}
175
176static int __init vfio_ap_init(void)
177{
178 int ret;
179
180 /* If there are no AP instructions, there is nothing to pass through. */
181 if (!ap_instructions_available())
182 return -ENODEV;
183
184 ret = vfio_ap_matrix_dev_create();
185 if (ret)
186 return ret;
187
188 ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
189 if (ret) {
190 vfio_ap_matrix_dev_destroy();
191 return ret;
192 }
193
194 ret = vfio_ap_mdev_register();
195 if (ret) {
196 ap_driver_unregister(&vfio_ap_drv);
197 vfio_ap_matrix_dev_destroy();
198
199 return ret;
200 }
201
202 return 0;
203}
204
205static void __exit vfio_ap_exit(void)
206{
207 vfio_ap_mdev_unregister();
208 ap_driver_unregister(&vfio_ap_drv);
209 vfio_ap_matrix_dev_destroy();
210}
211
212module_init(vfio_ap_init);
213module_exit(vfio_ap_exit);