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
21 MODULE_AUTHOR("IBM Corporation");
22 MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
23 MODULE_LICENSE("GPL v2");
24
25 static struct ap_driver vfio_ap_drv;
26
27 struct ap_matrix_dev *matrix_dev;
28
29 /* Only type 10 adapters (CEX4 and later) are supported
30 * by the AP matrix device driver
31 */
32 static struct ap_device_id ap_queue_ids[] = {
33 { .dev_type = AP_DEVICE_TYPE_CEX4,
34 .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
35 { .dev_type = AP_DEVICE_TYPE_CEX5,
36 .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
37 { .dev_type = AP_DEVICE_TYPE_CEX6,
38 .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
39 { .dev_type = AP_DEVICE_TYPE_CEX7,
40 .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
41 { /* end of sibling */ },
42 };
43
44 MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
45
46 /**
47 * vfio_ap_queue_dev_probe:
48 *
49 * Allocate a vfio_ap_queue structure and associate it
50 * with the device as driver_data.
51 */
vfio_ap_queue_dev_probe(struct ap_device * apdev)52 static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
53 {
54 struct vfio_ap_queue *q;
55
56 q = kzalloc(sizeof(*q), GFP_KERNEL);
57 if (!q)
58 return -ENOMEM;
59 dev_set_drvdata(&apdev->device, q);
60 q->apqn = to_ap_queue(&apdev->device)->qid;
61 q->saved_isc = VFIO_AP_ISC_INVALID;
62 return 0;
63 }
64
65 /**
66 * vfio_ap_queue_dev_remove:
67 *
68 * Takes the matrix lock to avoid actions on this device while removing
69 * Free the associated vfio_ap_queue structure
70 */
vfio_ap_queue_dev_remove(struct ap_device * apdev)71 static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
72 {
73 struct vfio_ap_queue *q;
74
75 mutex_lock(&matrix_dev->lock);
76 q = dev_get_drvdata(&apdev->device);
77 vfio_ap_mdev_reset_queue(q, 1);
78 dev_set_drvdata(&apdev->device, NULL);
79 kfree(q);
80 mutex_unlock(&matrix_dev->lock);
81 }
82
vfio_ap_matrix_dev_release(struct device * dev)83 static void vfio_ap_matrix_dev_release(struct device *dev)
84 {
85 struct ap_matrix_dev *matrix_dev;
86
87 matrix_dev = container_of(dev, struct ap_matrix_dev, device);
88 kfree(matrix_dev);
89 }
90
matrix_bus_match(struct device * dev,struct device_driver * drv)91 static int matrix_bus_match(struct device *dev, struct device_driver *drv)
92 {
93 return 1;
94 }
95
96 static struct bus_type matrix_bus = {
97 .name = "matrix",
98 .match = &matrix_bus_match,
99 };
100
101 static struct device_driver matrix_driver = {
102 .name = "vfio_ap",
103 .bus = &matrix_bus,
104 .suppress_bind_attrs = true,
105 };
106
vfio_ap_matrix_dev_create(void)107 static int vfio_ap_matrix_dev_create(void)
108 {
109 int ret;
110 struct device *root_device;
111
112 root_device = root_device_register(VFIO_AP_ROOT_NAME);
113 if (IS_ERR(root_device))
114 return PTR_ERR(root_device);
115
116 ret = bus_register(&matrix_bus);
117 if (ret)
118 goto bus_register_err;
119
120 matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
121 if (!matrix_dev) {
122 ret = -ENOMEM;
123 goto matrix_alloc_err;
124 }
125
126 /* Fill in config info via PQAP(QCI), if available */
127 if (test_facility(12)) {
128 ret = ap_qci(&matrix_dev->info);
129 if (ret)
130 goto matrix_alloc_err;
131 }
132
133 mutex_init(&matrix_dev->lock);
134 INIT_LIST_HEAD(&matrix_dev->mdev_list);
135
136 dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
137 matrix_dev->device.parent = root_device;
138 matrix_dev->device.bus = &matrix_bus;
139 matrix_dev->device.release = vfio_ap_matrix_dev_release;
140 matrix_dev->vfio_ap_drv = &vfio_ap_drv;
141
142 ret = device_register(&matrix_dev->device);
143 if (ret)
144 goto matrix_reg_err;
145
146 ret = driver_register(&matrix_driver);
147 if (ret)
148 goto matrix_drv_err;
149
150 return 0;
151
152 matrix_drv_err:
153 device_unregister(&matrix_dev->device);
154 matrix_reg_err:
155 put_device(&matrix_dev->device);
156 matrix_alloc_err:
157 bus_unregister(&matrix_bus);
158 bus_register_err:
159 root_device_unregister(root_device);
160 return ret;
161 }
162
vfio_ap_matrix_dev_destroy(void)163 static void vfio_ap_matrix_dev_destroy(void)
164 {
165 struct device *root_device = matrix_dev->device.parent;
166
167 driver_unregister(&matrix_driver);
168 device_unregister(&matrix_dev->device);
169 bus_unregister(&matrix_bus);
170 root_device_unregister(root_device);
171 }
172
vfio_ap_init(void)173 static int __init vfio_ap_init(void)
174 {
175 int ret;
176
177 /* If there are no AP instructions, there is nothing to pass through. */
178 if (!ap_instructions_available())
179 return -ENODEV;
180
181 ret = vfio_ap_matrix_dev_create();
182 if (ret)
183 return ret;
184
185 memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
186 vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
187 vfio_ap_drv.remove = vfio_ap_queue_dev_remove;
188 vfio_ap_drv.ids = ap_queue_ids;
189
190 ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
191 if (ret) {
192 vfio_ap_matrix_dev_destroy();
193 return ret;
194 }
195
196 ret = vfio_ap_mdev_register();
197 if (ret) {
198 ap_driver_unregister(&vfio_ap_drv);
199 vfio_ap_matrix_dev_destroy();
200
201 return ret;
202 }
203
204 return 0;
205 }
206
vfio_ap_exit(void)207 static void __exit vfio_ap_exit(void)
208 {
209 vfio_ap_mdev_unregister();
210 ap_driver_unregister(&vfio_ap_drv);
211 vfio_ap_matrix_dev_destroy();
212 }
213
214 module_init(vfio_ap_init);
215 module_exit(vfio_ap_exit);
216