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
10extern int device_driver_attach(struct device_driver *drv, struct device *dev);
11extern 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
17static ssize_t unbind_store(struct device_driver *drv, const char *buf, size_t count)
18{
19	const 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}
31static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, 0200, NULL, unbind_store);
32
33static ssize_t bind_store(struct device_driver *drv, const char *buf, size_t count)
34{
35	const 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}
65static DRIVER_ATTR_IGNORE_LOCKDEP(bind, 0200, NULL, bind_store);
66
67static struct attribute *dsa_drv_compat_attrs[] = {
68	&driver_attr_bind.attr,
69	&driver_attr_unbind.attr,
70	NULL,
71};
72
73static const struct attribute_group dsa_drv_compat_attr_group = {
74	.attrs = dsa_drv_compat_attrs,
75};
76
77static const struct attribute_group *dsa_drv_compat_groups[] = {
78	&dsa_drv_compat_attr_group,
79	NULL,
80};
81
82static int idxd_dsa_drv_probe(struct idxd_dev *idxd_dev)
83{
84	return -ENODEV;
85}
86
87static void idxd_dsa_drv_remove(struct idxd_dev *idxd_dev)
88{
89}
90
91static enum idxd_dev_type dev_types[] = {
92	IDXD_DEV_NONE,
93};
94
95struct 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
106module_idxd_driver(dsa_drv);
107MODULE_IMPORT_NS(IDXD);
108