1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2021 Intel Corporation. All rights rsvd. */
3 #include <linux/init.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/device.h>
7 #include <linux/device/bus.h>
8 #include "idxd.h"
9
10 extern void device_driver_detach(struct device *dev);
11
12 #define DRIVER_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
13 struct driver_attribute driver_attr_##_name = \
14 __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
15
unbind_store(struct device_driver * drv,const char * buf,size_t count)16 static ssize_t unbind_store(struct device_driver *drv, const char *buf, size_t count)
17 {
18 const struct bus_type *bus = drv->bus;
19 struct device *dev;
20 int rc = -ENODEV;
21
22 dev = bus_find_device_by_name(bus, NULL, buf);
23 if (!dev)
24 return -ENODEV;
25
26 if (dev->driver) {
27 device_driver_detach(dev);
28 rc = count;
29 }
30
31 put_device(dev);
32
33 return rc;
34 }
35 static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, 0200, NULL, unbind_store);
36
bind_store(struct device_driver * drv,const char * buf,size_t count)37 static ssize_t bind_store(struct device_driver *drv, const char *buf, size_t count)
38 {
39 const struct bus_type *bus = drv->bus;
40 struct device *dev;
41 struct device_driver *alt_drv = NULL;
42 int rc = -ENODEV;
43 struct idxd_dev *idxd_dev;
44
45 dev = bus_find_device_by_name(bus, NULL, buf);
46 if (!dev)
47 return -ENODEV;
48
49 if (dev->driver || drv != &dsa_drv.drv)
50 goto err_put_dev;
51
52 idxd_dev = confdev_to_idxd_dev(dev);
53 if (is_idxd_dev(idxd_dev)) {
54 alt_drv = driver_find("idxd", bus);
55 } else if (is_idxd_wq_dev(idxd_dev)) {
56 struct idxd_wq *wq = confdev_to_wq(dev);
57
58 if (is_idxd_wq_kernel(wq))
59 alt_drv = driver_find("dmaengine", bus);
60 else if (is_idxd_wq_user(wq))
61 alt_drv = driver_find("user", bus);
62 }
63 if (!alt_drv)
64 goto err_put_dev;
65
66 rc = device_driver_attach(alt_drv, dev);
67 if (rc < 0)
68 goto err_put_dev;
69
70 put_device(dev);
71
72 return count;
73
74 err_put_dev:
75 put_device(dev);
76
77 return rc;
78 }
79 static DRIVER_ATTR_IGNORE_LOCKDEP(bind, 0200, NULL, bind_store);
80
81 static struct attribute *dsa_drv_compat_attrs[] = {
82 &driver_attr_bind.attr,
83 &driver_attr_unbind.attr,
84 NULL,
85 };
86
87 static const struct attribute_group dsa_drv_compat_attr_group = {
88 .attrs = dsa_drv_compat_attrs,
89 };
90
91 static const struct attribute_group *dsa_drv_compat_groups[] = {
92 &dsa_drv_compat_attr_group,
93 NULL,
94 };
95
idxd_dsa_drv_probe(struct idxd_dev * idxd_dev)96 static int idxd_dsa_drv_probe(struct idxd_dev *idxd_dev)
97 {
98 return -ENODEV;
99 }
100
idxd_dsa_drv_remove(struct idxd_dev * idxd_dev)101 static void idxd_dsa_drv_remove(struct idxd_dev *idxd_dev)
102 {
103 }
104
105 static enum idxd_dev_type dev_types[] = {
106 IDXD_DEV_NONE,
107 };
108
109 struct idxd_device_driver dsa_drv = {
110 .name = "dsa",
111 .probe = idxd_dsa_drv_probe,
112 .remove = idxd_dsa_drv_remove,
113 .type = dev_types,
114 .drv = {
115 .suppress_bind_attrs = true,
116 .groups = dsa_drv_compat_groups,
117 },
118 };
119
120 module_idxd_driver(dsa_drv);
121 MODULE_IMPORT_NS("IDXD");
122