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  */
9 
10 #include <linux/module.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
14 #include <asm/facility.h>
15 #include "vfio_ap_private.h"
16 
17 #define VFIO_AP_ROOT_NAME "vfio_ap"
18 #define VFIO_AP_DEV_NAME "matrix"
19 
20 MODULE_AUTHOR("IBM Corporation");
21 MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
22 MODULE_LICENSE("GPL v2");
23 
24 static struct ap_driver vfio_ap_drv;
25 
26 struct ap_matrix_dev *matrix_dev;
27 
28 /* Only type 10 adapters (CEX4 and later) are supported
29  * by the AP matrix device driver
30  */
31 static struct ap_device_id ap_queue_ids[] = {
32 	{ .dev_type = AP_DEVICE_TYPE_CEX4,
33 	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
34 	{ .dev_type = AP_DEVICE_TYPE_CEX5,
35 	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
36 	{ .dev_type = AP_DEVICE_TYPE_CEX6,
37 	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
38 	{ /* end of sibling */ },
39 };
40 
41 MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
42 
43 static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
44 {
45 	return 0;
46 }
47 
48 static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
49 {
50 	/* Nothing to do yet */
51 }
52 
53 static void vfio_ap_matrix_dev_release(struct device *dev)
54 {
55 	struct ap_matrix_dev *matrix_dev = dev_get_drvdata(dev);
56 
57 	kfree(matrix_dev);
58 }
59 
60 static int matrix_bus_match(struct device *dev, struct device_driver *drv)
61 {
62 	return 1;
63 }
64 
65 static struct bus_type matrix_bus = {
66 	.name = "matrix",
67 	.match = &matrix_bus_match,
68 };
69 
70 static struct device_driver matrix_driver = {
71 	.name = "vfio_ap",
72 	.bus = &matrix_bus,
73 	.suppress_bind_attrs = true,
74 };
75 
76 static int vfio_ap_matrix_dev_create(void)
77 {
78 	int ret;
79 	struct device *root_device;
80 
81 	root_device = root_device_register(VFIO_AP_ROOT_NAME);
82 	if (IS_ERR(root_device))
83 		return PTR_ERR(root_device);
84 
85 	ret = bus_register(&matrix_bus);
86 	if (ret)
87 		goto bus_register_err;
88 
89 	matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
90 	if (!matrix_dev) {
91 		ret = -ENOMEM;
92 		goto matrix_alloc_err;
93 	}
94 
95 	/* Fill in config info via PQAP(QCI), if available */
96 	if (test_facility(12)) {
97 		ret = ap_qci(&matrix_dev->info);
98 		if (ret)
99 			goto matrix_alloc_err;
100 	}
101 
102 	mutex_init(&matrix_dev->lock);
103 	INIT_LIST_HEAD(&matrix_dev->mdev_list);
104 
105 	dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
106 	matrix_dev->device.parent = root_device;
107 	matrix_dev->device.bus = &matrix_bus;
108 	matrix_dev->device.release = vfio_ap_matrix_dev_release;
109 	matrix_dev->vfio_ap_drv = &vfio_ap_drv;
110 
111 	ret = device_register(&matrix_dev->device);
112 	if (ret)
113 		goto matrix_reg_err;
114 
115 	ret = driver_register(&matrix_driver);
116 	if (ret)
117 		goto matrix_drv_err;
118 
119 	return 0;
120 
121 matrix_drv_err:
122 	device_unregister(&matrix_dev->device);
123 matrix_reg_err:
124 	put_device(&matrix_dev->device);
125 matrix_alloc_err:
126 	bus_unregister(&matrix_bus);
127 bus_register_err:
128 	root_device_unregister(root_device);
129 	return ret;
130 }
131 
132 static void vfio_ap_matrix_dev_destroy(void)
133 {
134 	struct device *root_device = matrix_dev->device.parent;
135 
136 	driver_unregister(&matrix_driver);
137 	device_unregister(&matrix_dev->device);
138 	bus_unregister(&matrix_bus);
139 	root_device_unregister(root_device);
140 }
141 
142 static int __init vfio_ap_init(void)
143 {
144 	int ret;
145 
146 	/* If there are no AP instructions, there is nothing to pass through. */
147 	if (!ap_instructions_available())
148 		return -ENODEV;
149 
150 	ret = vfio_ap_matrix_dev_create();
151 	if (ret)
152 		return ret;
153 
154 	memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
155 	vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
156 	vfio_ap_drv.remove = vfio_ap_queue_dev_remove;
157 	vfio_ap_drv.ids = ap_queue_ids;
158 
159 	ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
160 	if (ret) {
161 		vfio_ap_matrix_dev_destroy();
162 		return ret;
163 	}
164 
165 	ret = vfio_ap_mdev_register();
166 	if (ret) {
167 		ap_driver_unregister(&vfio_ap_drv);
168 		vfio_ap_matrix_dev_destroy();
169 
170 		return ret;
171 	}
172 
173 	return 0;
174 }
175 
176 static void __exit vfio_ap_exit(void)
177 {
178 	vfio_ap_mdev_unregister();
179 	ap_driver_unregister(&vfio_ap_drv);
180 	vfio_ap_matrix_dev_destroy();
181 }
182 
183 module_init(vfio_ap_init);
184 module_exit(vfio_ap_exit);
185