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
21MODULE_AUTHOR("IBM Corporation");
22MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
23MODULE_LICENSE("GPL v2");
24
25static struct ap_driver vfio_ap_drv;
26
27struct ap_matrix_dev *matrix_dev;
28
29/* Only type 10 adapters (CEX4 and later) are supported
30 * by the AP matrix device driver
31 */
32static struct ap_device_id ap_queue_ids[] = {
33	{ .dev_type = AP_DEVICE_TYPE_CEX4,
34	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
35	{ .dev_type = AP_DEVICE_TYPE_CEX5,
36	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
37	{ .dev_type = AP_DEVICE_TYPE_CEX6,
38	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
39	{ .dev_type = AP_DEVICE_TYPE_CEX7,
40	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
41	{ /* end of sibling */ },
42};
43
44MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
45
46/**
47 * vfio_ap_queue_dev_probe:
48 *
49 * Allocate a vfio_ap_queue structure and associate it
50 * with the device as driver_data.
51 */
52static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
53{
54	struct vfio_ap_queue *q;
55
56	q = kzalloc(sizeof(*q), GFP_KERNEL);
57	if (!q)
58		return -ENOMEM;
59	dev_set_drvdata(&apdev->device, q);
60	q->apqn = to_ap_queue(&apdev->device)->qid;
61	q->saved_isc = VFIO_AP_ISC_INVALID;
62	return 0;
63}
64
65/**
66 * vfio_ap_queue_dev_remove:
67 *
68 * Takes the matrix lock to avoid actions on this device while removing
69 * Free the associated vfio_ap_queue structure
70 */
71static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
72{
73	struct vfio_ap_queue *q;
74
75	mutex_lock(&matrix_dev->lock);
76	q = dev_get_drvdata(&apdev->device);
77	vfio_ap_mdev_reset_queue(q, 1);
78	dev_set_drvdata(&apdev->device, NULL);
79	kfree(q);
80	mutex_unlock(&matrix_dev->lock);
81}
82
83static void vfio_ap_matrix_dev_release(struct device *dev)
84{
85	struct ap_matrix_dev *matrix_dev;
86
87	matrix_dev = container_of(dev, struct ap_matrix_dev, device);
88	kfree(matrix_dev);
89}
90
91static int matrix_bus_match(struct device *dev, struct device_driver *drv)
92{
93	return 1;
94}
95
96static struct bus_type matrix_bus = {
97	.name = "matrix",
98	.match = &matrix_bus_match,
99};
100
101static struct device_driver matrix_driver = {
102	.name = "vfio_ap",
103	.bus = &matrix_bus,
104	.suppress_bind_attrs = true,
105};
106
107static int vfio_ap_matrix_dev_create(void)
108{
109	int ret;
110	struct device *root_device;
111
112	root_device = root_device_register(VFIO_AP_ROOT_NAME);
113	if (IS_ERR(root_device))
114		return PTR_ERR(root_device);
115
116	ret = bus_register(&matrix_bus);
117	if (ret)
118		goto bus_register_err;
119
120	matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
121	if (!matrix_dev) {
122		ret = -ENOMEM;
123		goto matrix_alloc_err;
124	}
125
126	/* Fill in config info via PQAP(QCI), if available */
127	if (test_facility(12)) {
128		ret = ap_qci(&matrix_dev->info);
129		if (ret)
130			goto matrix_alloc_err;
131	}
132
133	mutex_init(&matrix_dev->lock);
134	INIT_LIST_HEAD(&matrix_dev->mdev_list);
135
136	dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
137	matrix_dev->device.parent = root_device;
138	matrix_dev->device.bus = &matrix_bus;
139	matrix_dev->device.release = vfio_ap_matrix_dev_release;
140	matrix_dev->vfio_ap_drv = &vfio_ap_drv;
141
142	ret = device_register(&matrix_dev->device);
143	if (ret)
144		goto matrix_reg_err;
145
146	ret = driver_register(&matrix_driver);
147	if (ret)
148		goto matrix_drv_err;
149
150	return 0;
151
152matrix_drv_err:
153	device_unregister(&matrix_dev->device);
154matrix_reg_err:
155	put_device(&matrix_dev->device);
156matrix_alloc_err:
157	bus_unregister(&matrix_bus);
158bus_register_err:
159	root_device_unregister(root_device);
160	return ret;
161}
162
163static void vfio_ap_matrix_dev_destroy(void)
164{
165	struct device *root_device = matrix_dev->device.parent;
166
167	driver_unregister(&matrix_driver);
168	device_unregister(&matrix_dev->device);
169	bus_unregister(&matrix_bus);
170	root_device_unregister(root_device);
171}
172
173static int __init vfio_ap_init(void)
174{
175	int ret;
176
177	/* If there are no AP instructions, there is nothing to pass through. */
178	if (!ap_instructions_available())
179		return -ENODEV;
180
181	ret = vfio_ap_matrix_dev_create();
182	if (ret)
183		return ret;
184
185	memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
186	vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
187	vfio_ap_drv.remove = vfio_ap_queue_dev_remove;
188	vfio_ap_drv.ids = ap_queue_ids;
189
190	ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
191	if (ret) {
192		vfio_ap_matrix_dev_destroy();
193		return ret;
194	}
195
196	ret = vfio_ap_mdev_register();
197	if (ret) {
198		ap_driver_unregister(&vfio_ap_drv);
199		vfio_ap_matrix_dev_destroy();
200
201		return ret;
202	}
203
204	return 0;
205}
206
207static void __exit vfio_ap_exit(void)
208{
209	vfio_ap_mdev_unregister();
210	ap_driver_unregister(&vfio_ap_drv);
211	vfio_ap_matrix_dev_destroy();
212}
213
214module_init(vfio_ap_init);
215module_exit(vfio_ap_exit);
216