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 struct ap_matrix_dev *matrix_dev;
26
27 /* Only type 10 adapters (CEX4 and later) are supported
28 * by the AP matrix device driver
29 */
30 static 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
42 MODULE_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 */
vfio_ap_queue_dev_probe(struct ap_device * apdev)50 static 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 */
vfio_ap_queue_dev_remove(struct ap_device * apdev)69 static 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
81 static 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
vfio_ap_matrix_dev_release(struct device * dev)87 static void vfio_ap_matrix_dev_release(struct device *dev)
88 {
89 struct ap_matrix_dev *matrix_dev;
90
91 matrix_dev = container_of(dev, struct ap_matrix_dev, device);
92 kfree(matrix_dev);
93 }
94
matrix_bus_match(struct device * dev,struct device_driver * drv)95 static int matrix_bus_match(struct device *dev, struct device_driver *drv)
96 {
97 return 1;
98 }
99
100 static struct bus_type matrix_bus = {
101 .name = "matrix",
102 .match = &matrix_bus_match,
103 };
104
105 static struct device_driver matrix_driver = {
106 .name = "vfio_ap",
107 .bus = &matrix_bus,
108 .suppress_bind_attrs = true,
109 };
110
vfio_ap_matrix_dev_create(void)111 static int vfio_ap_matrix_dev_create(void)
112 {
113 int ret;
114 struct device *root_device;
115
116 root_device = root_device_register(VFIO_AP_ROOT_NAME);
117 if (IS_ERR(root_device))
118 return PTR_ERR(root_device);
119
120 ret = bus_register(&matrix_bus);
121 if (ret)
122 goto bus_register_err;
123
124 matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
125 if (!matrix_dev) {
126 ret = -ENOMEM;
127 goto matrix_alloc_err;
128 }
129
130 /* Fill in config info via PQAP(QCI), if available */
131 if (test_facility(12)) {
132 ret = ap_qci(&matrix_dev->info);
133 if (ret)
134 goto matrix_alloc_err;
135 }
136
137 mutex_init(&matrix_dev->lock);
138 INIT_LIST_HEAD(&matrix_dev->mdev_list);
139
140 dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
141 matrix_dev->device.parent = root_device;
142 matrix_dev->device.bus = &matrix_bus;
143 matrix_dev->device.release = vfio_ap_matrix_dev_release;
144 matrix_dev->vfio_ap_drv = &vfio_ap_drv;
145
146 ret = device_register(&matrix_dev->device);
147 if (ret)
148 goto matrix_reg_err;
149
150 ret = driver_register(&matrix_driver);
151 if (ret)
152 goto matrix_drv_err;
153
154 return 0;
155
156 matrix_drv_err:
157 device_unregister(&matrix_dev->device);
158 matrix_reg_err:
159 put_device(&matrix_dev->device);
160 matrix_alloc_err:
161 bus_unregister(&matrix_bus);
162 bus_register_err:
163 root_device_unregister(root_device);
164 return ret;
165 }
166
vfio_ap_matrix_dev_destroy(void)167 static void vfio_ap_matrix_dev_destroy(void)
168 {
169 struct device *root_device = matrix_dev->device.parent;
170
171 driver_unregister(&matrix_driver);
172 device_unregister(&matrix_dev->device);
173 bus_unregister(&matrix_bus);
174 root_device_unregister(root_device);
175 }
176
vfio_ap_init(void)177 static int __init vfio_ap_init(void)
178 {
179 int ret;
180
181 /* If there are no AP instructions, there is nothing to pass through. */
182 if (!ap_instructions_available())
183 return -ENODEV;
184
185 ret = vfio_ap_matrix_dev_create();
186 if (ret)
187 return ret;
188
189 ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
190 if (ret) {
191 vfio_ap_matrix_dev_destroy();
192 return ret;
193 }
194
195 ret = vfio_ap_mdev_register();
196 if (ret) {
197 ap_driver_unregister(&vfio_ap_drv);
198 vfio_ap_matrix_dev_destroy();
199
200 return ret;
201 }
202
203 return 0;
204 }
205
vfio_ap_exit(void)206 static void __exit vfio_ap_exit(void)
207 {
208 vfio_ap_mdev_unregister();
209 ap_driver_unregister(&vfio_ap_drv);
210 vfio_ap_matrix_dev_destroy();
211 }
212
213 module_init(vfio_ap_init);
214 module_exit(vfio_ap_exit);
215