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: Allocate a vfio_ap_queue structure and associate it
46 * with the device as driver_data.
47 *
48 * @apdev: the AP device being probed
49 *
50 * Return: returns 0 if the probe succeeded; otherwise, returns -ENOMEM if
51 * storage could not be allocated for a vfio_ap_queue object.
52 */
vfio_ap_queue_dev_probe(struct ap_device * apdev)53 static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
54 {
55 struct vfio_ap_queue *q;
56
57 q = kzalloc(sizeof(*q), GFP_KERNEL);
58 if (!q)
59 return -ENOMEM;
60 dev_set_drvdata(&apdev->device, q);
61 q->apqn = to_ap_queue(&apdev->device)->qid;
62 q->saved_isc = VFIO_AP_ISC_INVALID;
63 return 0;
64 }
65
66 /**
67 * vfio_ap_queue_dev_remove: Free the associated vfio_ap_queue structure.
68 *
69 * @apdev: the AP device being removed
70 *
71 * Takes the matrix lock to avoid actions on this device while doing the remove.
72 */
vfio_ap_queue_dev_remove(struct ap_device * apdev)73 static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
74 {
75 struct vfio_ap_queue *q;
76
77 mutex_lock(&matrix_dev->lock);
78 q = dev_get_drvdata(&apdev->device);
79 vfio_ap_mdev_reset_queue(q, 1);
80 dev_set_drvdata(&apdev->device, NULL);
81 kfree(q);
82 mutex_unlock(&matrix_dev->lock);
83 }
84
85 static struct ap_driver vfio_ap_drv = {
86 .probe = vfio_ap_queue_dev_probe,
87 .remove = vfio_ap_queue_dev_remove,
88 .ids = ap_queue_ids,
89 };
90
vfio_ap_matrix_dev_release(struct device * dev)91 static void vfio_ap_matrix_dev_release(struct device *dev)
92 {
93 struct ap_matrix_dev *matrix_dev = dev_get_drvdata(dev);
94
95 kfree(matrix_dev);
96 }
97
matrix_bus_match(struct device * dev,struct device_driver * drv)98 static int matrix_bus_match(struct device *dev, struct device_driver *drv)
99 {
100 return 1;
101 }
102
103 static struct bus_type matrix_bus = {
104 .name = "matrix",
105 .match = &matrix_bus_match,
106 };
107
108 static struct device_driver matrix_driver = {
109 .name = "vfio_ap",
110 .bus = &matrix_bus,
111 .suppress_bind_attrs = true,
112 };
113
vfio_ap_matrix_dev_create(void)114 static int vfio_ap_matrix_dev_create(void)
115 {
116 int ret;
117 struct device *root_device;
118
119 root_device = root_device_register(VFIO_AP_ROOT_NAME);
120 if (IS_ERR(root_device))
121 return PTR_ERR(root_device);
122
123 ret = bus_register(&matrix_bus);
124 if (ret)
125 goto bus_register_err;
126
127 matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
128 if (!matrix_dev) {
129 ret = -ENOMEM;
130 goto matrix_alloc_err;
131 }
132
133 /* Fill in config info via PQAP(QCI), if available */
134 if (test_facility(12)) {
135 ret = ap_qci(&matrix_dev->info);
136 if (ret)
137 goto matrix_alloc_err;
138 }
139
140 mutex_init(&matrix_dev->lock);
141 INIT_LIST_HEAD(&matrix_dev->mdev_list);
142
143 dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
144 matrix_dev->device.parent = root_device;
145 matrix_dev->device.bus = &matrix_bus;
146 matrix_dev->device.release = vfio_ap_matrix_dev_release;
147 matrix_dev->vfio_ap_drv = &vfio_ap_drv;
148
149 ret = device_register(&matrix_dev->device);
150 if (ret)
151 goto matrix_reg_err;
152
153 ret = driver_register(&matrix_driver);
154 if (ret)
155 goto matrix_drv_err;
156
157 return 0;
158
159 matrix_drv_err:
160 device_unregister(&matrix_dev->device);
161 matrix_reg_err:
162 put_device(&matrix_dev->device);
163 matrix_alloc_err:
164 bus_unregister(&matrix_bus);
165 bus_register_err:
166 root_device_unregister(root_device);
167 return ret;
168 }
169
vfio_ap_matrix_dev_destroy(void)170 static void vfio_ap_matrix_dev_destroy(void)
171 {
172 struct device *root_device = matrix_dev->device.parent;
173
174 driver_unregister(&matrix_driver);
175 device_unregister(&matrix_dev->device);
176 bus_unregister(&matrix_bus);
177 root_device_unregister(root_device);
178 }
179
vfio_ap_init(void)180 static int __init vfio_ap_init(void)
181 {
182 int ret;
183
184 /* If there are no AP instructions, there is nothing to pass through. */
185 if (!ap_instructions_available())
186 return -ENODEV;
187
188 ret = vfio_ap_matrix_dev_create();
189 if (ret)
190 return ret;
191
192 ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
193 if (ret) {
194 vfio_ap_matrix_dev_destroy();
195 return ret;
196 }
197
198 ret = vfio_ap_mdev_register();
199 if (ret) {
200 ap_driver_unregister(&vfio_ap_drv);
201 vfio_ap_matrix_dev_destroy();
202
203 return ret;
204 }
205
206 return 0;
207 }
208
vfio_ap_exit(void)209 static void __exit vfio_ap_exit(void)
210 {
211 vfio_ap_mdev_unregister();
212 ap_driver_unregister(&vfio_ap_drv);
213 vfio_ap_matrix_dev_destroy();
214 }
215
216 module_init(vfio_ap_init);
217 module_exit(vfio_ap_exit);
218