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  */
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  */
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 
87 static 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 
94 static int matrix_bus_match(struct device *dev, struct device_driver *drv)
95 {
96 	return 1;
97 }
98 
99 static struct bus_type matrix_bus = {
100 	.name = "matrix",
101 	.match = &matrix_bus_match,
102 };
103 
104 static struct device_driver matrix_driver = {
105 	.name = "vfio_ap",
106 	.bus = &matrix_bus,
107 	.suppress_bind_attrs = true,
108 };
109 
110 static 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 
155 matrix_drv_err:
156 	device_unregister(&matrix_dev->device);
157 matrix_reg_err:
158 	put_device(&matrix_dev->device);
159 matrix_alloc_err:
160 	bus_unregister(&matrix_bus);
161 bus_register_err:
162 	root_device_unregister(root_device);
163 	return ret;
164 }
165 
166 static 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 
176 static 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 
205 static 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 
212 module_init(vfio_ap_init);
213 module_exit(vfio_ap_exit);
214