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