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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device.c (7218B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2018 Cadence Design Systems Inc.
      4 *
      5 * Author: Boris Brezillon <boris.brezillon@bootlin.com>
      6 */
      7
      8#include <linux/atomic.h>
      9#include <linux/bug.h>
     10#include <linux/completion.h>
     11#include <linux/device.h>
     12#include <linux/mutex.h>
     13#include <linux/slab.h>
     14
     15#include "internals.h"
     16
     17/**
     18 * i3c_device_do_priv_xfers() - do I3C SDR private transfers directed to a
     19 *				specific device
     20 *
     21 * @dev: device with which the transfers should be done
     22 * @xfers: array of transfers
     23 * @nxfers: number of transfers
     24 *
     25 * Initiate one or several private SDR transfers with @dev.
     26 *
     27 * This function can sleep and thus cannot be called in atomic context.
     28 *
     29 * Return: 0 in case of success, a negative error core otherwise.
     30 */
     31int i3c_device_do_priv_xfers(struct i3c_device *dev,
     32			     struct i3c_priv_xfer *xfers,
     33			     int nxfers)
     34{
     35	int ret, i;
     36
     37	if (nxfers < 1)
     38		return 0;
     39
     40	for (i = 0; i < nxfers; i++) {
     41		if (!xfers[i].len || !xfers[i].data.in)
     42			return -EINVAL;
     43	}
     44
     45	i3c_bus_normaluse_lock(dev->bus);
     46	ret = i3c_dev_do_priv_xfers_locked(dev->desc, xfers, nxfers);
     47	i3c_bus_normaluse_unlock(dev->bus);
     48
     49	return ret;
     50}
     51EXPORT_SYMBOL_GPL(i3c_device_do_priv_xfers);
     52
     53/**
     54 * i3c_device_get_info() - get I3C device information
     55 *
     56 * @dev: device we want information on
     57 * @info: the information object to fill in
     58 *
     59 * Retrieve I3C dev info.
     60 */
     61void i3c_device_get_info(struct i3c_device *dev,
     62			 struct i3c_device_info *info)
     63{
     64	if (!info)
     65		return;
     66
     67	i3c_bus_normaluse_lock(dev->bus);
     68	if (dev->desc)
     69		*info = dev->desc->info;
     70	i3c_bus_normaluse_unlock(dev->bus);
     71}
     72EXPORT_SYMBOL_GPL(i3c_device_get_info);
     73
     74/**
     75 * i3c_device_disable_ibi() - Disable IBIs coming from a specific device
     76 * @dev: device on which IBIs should be disabled
     77 *
     78 * This function disable IBIs coming from a specific device and wait for
     79 * all pending IBIs to be processed.
     80 *
     81 * Return: 0 in case of success, a negative error core otherwise.
     82 */
     83int i3c_device_disable_ibi(struct i3c_device *dev)
     84{
     85	int ret = -ENOENT;
     86
     87	i3c_bus_normaluse_lock(dev->bus);
     88	if (dev->desc) {
     89		mutex_lock(&dev->desc->ibi_lock);
     90		ret = i3c_dev_disable_ibi_locked(dev->desc);
     91		mutex_unlock(&dev->desc->ibi_lock);
     92	}
     93	i3c_bus_normaluse_unlock(dev->bus);
     94
     95	return ret;
     96}
     97EXPORT_SYMBOL_GPL(i3c_device_disable_ibi);
     98
     99/**
    100 * i3c_device_enable_ibi() - Enable IBIs coming from a specific device
    101 * @dev: device on which IBIs should be enabled
    102 *
    103 * This function enable IBIs coming from a specific device and wait for
    104 * all pending IBIs to be processed. This should be called on a device
    105 * where i3c_device_request_ibi() has succeeded.
    106 *
    107 * Note that IBIs from this device might be received before this function
    108 * returns to its caller.
    109 *
    110 * Return: 0 in case of success, a negative error core otherwise.
    111 */
    112int i3c_device_enable_ibi(struct i3c_device *dev)
    113{
    114	int ret = -ENOENT;
    115
    116	i3c_bus_normaluse_lock(dev->bus);
    117	if (dev->desc) {
    118		mutex_lock(&dev->desc->ibi_lock);
    119		ret = i3c_dev_enable_ibi_locked(dev->desc);
    120		mutex_unlock(&dev->desc->ibi_lock);
    121	}
    122	i3c_bus_normaluse_unlock(dev->bus);
    123
    124	return ret;
    125}
    126EXPORT_SYMBOL_GPL(i3c_device_enable_ibi);
    127
    128/**
    129 * i3c_device_request_ibi() - Request an IBI
    130 * @dev: device for which we should enable IBIs
    131 * @req: setup requested for this IBI
    132 *
    133 * This function is responsible for pre-allocating all resources needed to
    134 * process IBIs coming from @dev. When this function returns, the IBI is not
    135 * enabled until i3c_device_enable_ibi() is called.
    136 *
    137 * Return: 0 in case of success, a negative error core otherwise.
    138 */
    139int i3c_device_request_ibi(struct i3c_device *dev,
    140			   const struct i3c_ibi_setup *req)
    141{
    142	int ret = -ENOENT;
    143
    144	if (!req->handler || !req->num_slots)
    145		return -EINVAL;
    146
    147	i3c_bus_normaluse_lock(dev->bus);
    148	if (dev->desc) {
    149		mutex_lock(&dev->desc->ibi_lock);
    150		ret = i3c_dev_request_ibi_locked(dev->desc, req);
    151		mutex_unlock(&dev->desc->ibi_lock);
    152	}
    153	i3c_bus_normaluse_unlock(dev->bus);
    154
    155	return ret;
    156}
    157EXPORT_SYMBOL_GPL(i3c_device_request_ibi);
    158
    159/**
    160 * i3c_device_free_ibi() - Free all resources needed for IBI handling
    161 * @dev: device on which you want to release IBI resources
    162 *
    163 * This function is responsible for de-allocating resources previously
    164 * allocated by i3c_device_request_ibi(). It should be called after disabling
    165 * IBIs with i3c_device_disable_ibi().
    166 */
    167void i3c_device_free_ibi(struct i3c_device *dev)
    168{
    169	i3c_bus_normaluse_lock(dev->bus);
    170	if (dev->desc) {
    171		mutex_lock(&dev->desc->ibi_lock);
    172		i3c_dev_free_ibi_locked(dev->desc);
    173		mutex_unlock(&dev->desc->ibi_lock);
    174	}
    175	i3c_bus_normaluse_unlock(dev->bus);
    176}
    177EXPORT_SYMBOL_GPL(i3c_device_free_ibi);
    178
    179/**
    180 * i3cdev_to_dev() - Returns the device embedded in @i3cdev
    181 * @i3cdev: I3C device
    182 *
    183 * Return: a pointer to a device object.
    184 */
    185struct device *i3cdev_to_dev(struct i3c_device *i3cdev)
    186{
    187	return &i3cdev->dev;
    188}
    189EXPORT_SYMBOL_GPL(i3cdev_to_dev);
    190
    191/**
    192 * dev_to_i3cdev() - Returns the I3C device containing @dev
    193 * @dev: device object
    194 *
    195 * Return: a pointer to an I3C device object.
    196 */
    197struct i3c_device *dev_to_i3cdev(struct device *dev)
    198{
    199	return container_of(dev, struct i3c_device, dev);
    200}
    201EXPORT_SYMBOL_GPL(dev_to_i3cdev);
    202
    203/**
    204 * i3c_device_match_id() - Returns the i3c_device_id entry matching @i3cdev
    205 * @i3cdev: I3C device
    206 * @id_table: I3C device match table
    207 *
    208 * Return: a pointer to an i3c_device_id object or NULL if there's no match.
    209 */
    210const struct i3c_device_id *
    211i3c_device_match_id(struct i3c_device *i3cdev,
    212		    const struct i3c_device_id *id_table)
    213{
    214	struct i3c_device_info devinfo;
    215	const struct i3c_device_id *id;
    216	u16 manuf, part, ext_info;
    217	bool rndpid;
    218
    219	i3c_device_get_info(i3cdev, &devinfo);
    220
    221	manuf = I3C_PID_MANUF_ID(devinfo.pid);
    222	part = I3C_PID_PART_ID(devinfo.pid);
    223	ext_info = I3C_PID_EXTRA_INFO(devinfo.pid);
    224	rndpid = I3C_PID_RND_LOWER_32BITS(devinfo.pid);
    225
    226	for (id = id_table; id->match_flags != 0; id++) {
    227		if ((id->match_flags & I3C_MATCH_DCR) &&
    228		    id->dcr != devinfo.dcr)
    229			continue;
    230
    231		if ((id->match_flags & I3C_MATCH_MANUF) &&
    232		    id->manuf_id != manuf)
    233			continue;
    234
    235		if ((id->match_flags & I3C_MATCH_PART) &&
    236		    (rndpid || id->part_id != part))
    237			continue;
    238
    239		if ((id->match_flags & I3C_MATCH_EXTRA_INFO) &&
    240		    (rndpid || id->extra_info != ext_info))
    241			continue;
    242
    243		return id;
    244	}
    245
    246	return NULL;
    247}
    248EXPORT_SYMBOL_GPL(i3c_device_match_id);
    249
    250/**
    251 * i3c_driver_register_with_owner() - register an I3C device driver
    252 *
    253 * @drv: driver to register
    254 * @owner: module that owns this driver
    255 *
    256 * Register @drv to the core.
    257 *
    258 * Return: 0 in case of success, a negative error core otherwise.
    259 */
    260int i3c_driver_register_with_owner(struct i3c_driver *drv, struct module *owner)
    261{
    262	drv->driver.owner = owner;
    263	drv->driver.bus = &i3c_bus_type;
    264
    265	if (!drv->probe) {
    266		pr_err("Trying to register an i3c driver without probe callback\n");
    267		return -EINVAL;
    268	}
    269
    270	return driver_register(&drv->driver);
    271}
    272EXPORT_SYMBOL_GPL(i3c_driver_register_with_owner);
    273
    274/**
    275 * i3c_driver_unregister() - unregister an I3C device driver
    276 *
    277 * @drv: driver to unregister
    278 *
    279 * Unregister @drv.
    280 */
    281void i3c_driver_unregister(struct i3c_driver *drv)
    282{
    283	driver_unregister(&drv->driver);
    284}
    285EXPORT_SYMBOL_GPL(i3c_driver_unregister);