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 "vfio_ap_private.h"
15 
16 #define VFIO_AP_ROOT_NAME "vfio_ap"
17 #define VFIO_AP_DEV_TYPE_NAME "ap_matrix"
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 static struct device_type vfio_ap_dev_type = {
27 	.name = VFIO_AP_DEV_TYPE_NAME,
28 };
29 
30 struct ap_matrix_dev *matrix_dev;
31 
32 /* Only type 10 adapters (CEX4 and later) are supported
33  * by the AP matrix device driver
34  */
35 static struct ap_device_id ap_queue_ids[] = {
36 	{ .dev_type = AP_DEVICE_TYPE_CEX4,
37 	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
38 	{ .dev_type = AP_DEVICE_TYPE_CEX5,
39 	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
40 	{ .dev_type = AP_DEVICE_TYPE_CEX6,
41 	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
42 	{ /* end of sibling */ },
43 };
44 
45 MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
46 
47 static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
48 {
49 	return 0;
50 }
51 
52 static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
53 {
54 	/* Nothing to do yet */
55 }
56 
57 static void vfio_ap_matrix_dev_release(struct device *dev)
58 {
59 	struct ap_matrix_dev *matrix_dev = dev_get_drvdata(dev);
60 
61 	kfree(matrix_dev);
62 }
63 
64 static int vfio_ap_matrix_dev_create(void)
65 {
66 	int ret;
67 	struct device *root_device;
68 
69 	root_device = root_device_register(VFIO_AP_ROOT_NAME);
70 	if (IS_ERR(root_device))
71 		return PTR_ERR(root_device);
72 
73 	matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
74 	if (!matrix_dev) {
75 		ret = -ENOMEM;
76 		goto matrix_alloc_err;
77 	}
78 
79 	/* Fill in config info via PQAP(QCI), if available */
80 	if (test_facility(12)) {
81 		ret = ap_qci(&matrix_dev->info);
82 		if (ret)
83 			goto matrix_alloc_err;
84 	}
85 
86 	mutex_init(&matrix_dev->lock);
87 	INIT_LIST_HEAD(&matrix_dev->mdev_list);
88 
89 	matrix_dev->device.type = &vfio_ap_dev_type;
90 	dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
91 	matrix_dev->device.parent = root_device;
92 	matrix_dev->device.release = vfio_ap_matrix_dev_release;
93 	matrix_dev->device.driver = &vfio_ap_drv.driver;
94 
95 	ret = device_register(&matrix_dev->device);
96 	if (ret)
97 		goto matrix_reg_err;
98 
99 	return 0;
100 
101 matrix_reg_err:
102 	put_device(&matrix_dev->device);
103 matrix_alloc_err:
104 	root_device_unregister(root_device);
105 
106 	return ret;
107 }
108 
109 static void vfio_ap_matrix_dev_destroy(void)
110 {
111 	device_unregister(&matrix_dev->device);
112 	root_device_unregister(matrix_dev->device.parent);
113 }
114 
115 static int __init vfio_ap_init(void)
116 {
117 	int ret;
118 
119 	/* If there are no AP instructions, there is nothing to pass through. */
120 	if (!ap_instructions_available())
121 		return -ENODEV;
122 
123 	ret = vfio_ap_matrix_dev_create();
124 	if (ret)
125 		return ret;
126 
127 	memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
128 	vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
129 	vfio_ap_drv.remove = vfio_ap_queue_dev_remove;
130 	vfio_ap_drv.ids = ap_queue_ids;
131 
132 	ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
133 	if (ret) {
134 		vfio_ap_matrix_dev_destroy();
135 		return ret;
136 	}
137 
138 	ret = vfio_ap_mdev_register();
139 	if (ret) {
140 		ap_driver_unregister(&vfio_ap_drv);
141 		vfio_ap_matrix_dev_destroy();
142 
143 		return ret;
144 	}
145 
146 	return 0;
147 }
148 
149 static void __exit vfio_ap_exit(void)
150 {
151 	vfio_ap_mdev_unregister();
152 	ap_driver_unregister(&vfio_ap_drv);
153 	vfio_ap_matrix_dev_destroy();
154 }
155 
156 module_init(vfio_ap_init);
157 module_exit(vfio_ap_exit);
158