cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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dio-driver.c (3485B)

      1/*
      2 *  DIO Driver Services
      3 *
      4 *  Copyright (C) 2004 Jochen Friedrich
      5 *
      6 *  Loosely based on drivers/pci/pci-driver.c and drivers/zorro/zorro-driver.c
      7 *
      8 *  This file is subject to the terms and conditions of the GNU General Public
      9 *  License.  See the file COPYING in the main directory of this archive
     10 *  for more details.
     11 */
     12
     13#include <linux/init.h>
     14#include <linux/module.h>
     15#include <linux/dio.h>
     16
     17
     18/**
     19 *  dio_match_device - Tell if a DIO device structure has a matching DIO device id structure
     20 *  @ids: array of DIO device id structures to search in
     21 *  @d: the DIO device structure to match against
     22 *
     23 *  Used by a driver to check whether a DIO device present in the
     24 *  system is in its list of supported devices. Returns the matching
     25 *  dio_device_id structure or %NULL if there is no match.
     26 */
     27
     28static const struct dio_device_id *
     29dio_match_device(const struct dio_device_id *ids,
     30		   const struct dio_dev *d)
     31{
     32	while (ids->id) {
     33		if (ids->id == DIO_WILDCARD)
     34			return ids;
     35		if (DIO_NEEDSSECID(ids->id & 0xff)) {
     36			if (ids->id == d->id)
     37				return ids;
     38		} else {
     39			if ((ids->id & 0xff) == (d->id & 0xff))
     40				return ids;
     41		}
     42		ids++;
     43	}
     44	return NULL;
     45}
     46
     47static int dio_device_probe(struct device *dev)
     48{
     49	int error = 0;
     50	struct dio_driver *drv = to_dio_driver(dev->driver);
     51	struct dio_dev *d = to_dio_dev(dev);
     52
     53	if (!d->driver && drv->probe) {
     54		const struct dio_device_id *id;
     55
     56		id = dio_match_device(drv->id_table, d);
     57		if (id)
     58			error = drv->probe(d, id);
     59		if (error >= 0) {
     60			d->driver = drv;
     61			error = 0;
     62		}
     63	}
     64	return error;
     65}
     66
     67
     68/**
     69 *  dio_register_driver - register a new DIO driver
     70 *  @drv: the driver structure to register
     71 *
     72 *  Adds the driver structure to the list of registered drivers
     73 *  Returns zero or a negative error value.
     74 */
     75
     76int dio_register_driver(struct dio_driver *drv)
     77{
     78	/* initialize common driver fields */
     79	drv->driver.name = drv->name;
     80	drv->driver.bus = &dio_bus_type;
     81
     82	/* register with core */
     83	return driver_register(&drv->driver);
     84}
     85
     86
     87/**
     88 *  dio_unregister_driver - unregister a DIO driver
     89 *  @drv: the driver structure to unregister
     90 *
     91 *  Deletes the driver structure from the list of registered DIO drivers,
     92 *  gives it a chance to clean up by calling its remove() function for
     93 *  each device it was responsible for, and marks those devices as
     94 *  driverless.
     95 */
     96
     97void dio_unregister_driver(struct dio_driver *drv)
     98{
     99	driver_unregister(&drv->driver);
    100}
    101
    102
    103/**
    104 *  dio_bus_match - Tell if a DIO device structure has a matching DIO device id structure
    105 *  @dev: the DIO device structure to match against
    106 *  @drv: the &device_driver that points to the array of DIO device id structures to search
    107 *
    108 *  Used by the driver core to check whether a DIO device present in the
    109 *  system is in a driver's list of supported devices. Returns 1 if supported,
    110 *  and 0 if there is no match.
    111 */
    112
    113static int dio_bus_match(struct device *dev, struct device_driver *drv)
    114{
    115	struct dio_dev *d = to_dio_dev(dev);
    116	struct dio_driver *dio_drv = to_dio_driver(drv);
    117	const struct dio_device_id *ids = dio_drv->id_table;
    118
    119	if (!ids)
    120		return 0;
    121
    122	return dio_match_device(ids, d) ? 1 : 0;
    123}
    124
    125
    126struct bus_type dio_bus_type = {
    127	.name	= "dio",
    128	.match	= dio_bus_match,
    129	.probe	= dio_device_probe,
    130};
    131
    132
    133static int __init dio_driver_init(void)
    134{
    135	return bus_register(&dio_bus_type);
    136}
    137
    138postcore_initcall(dio_driver_init);
    139
    140EXPORT_SYMBOL(dio_register_driver);
    141EXPORT_SYMBOL(dio_unregister_driver);
    142EXPORT_SYMBOL(dio_bus_type);