compat.c

  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 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
 16static 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}
 35static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, 0200, NULL, unbind_store);
 36
 37static 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
 74err_put_dev:
 75	put_device(dev);
 76
 77	return rc;
 78}
 79static DRIVER_ATTR_IGNORE_LOCKDEP(bind, 0200, NULL, bind_store);
 80
 81static struct attribute *dsa_drv_compat_attrs[] = {
 82	&driver_attr_bind.attr,
 83	&driver_attr_unbind.attr,
 84	NULL,
 85};
 86
 87static const struct attribute_group dsa_drv_compat_attr_group = {
 88	.attrs = dsa_drv_compat_attrs,
 89};
 90
 91static const struct attribute_group *dsa_drv_compat_groups[] = {
 92	&dsa_drv_compat_attr_group,
 93	NULL,
 94};
 95
 96static int idxd_dsa_drv_probe(struct idxd_dev *idxd_dev)
 97{
 98	return -ENODEV;
 99}
100
101static void idxd_dsa_drv_remove(struct idxd_dev *idxd_dev)
102{
103}
104
105static enum idxd_dev_type dev_types[] = {
106	IDXD_DEV_NONE,
107};
108
109struct 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
120module_idxd_driver(dsa_drv);
121MODULE_IMPORT_NS("IDXD");