cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

of.c (3489B)

      1/*
      2 * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
      3 *
      4 * Permission to use, copy, modify, and/or distribute this software for any
      5 * purpose with or without fee is hereby granted, provided that the above
      6 * copyright notice and this permission notice appear in all copies.
      7 *
      8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     15 */
     16
     17#include <linux/of.h>
     18#include <net/cfg80211.h>
     19#include "core.h"
     20
     21static bool wiphy_freq_limits_valid_chan(struct wiphy *wiphy,
     22					 struct ieee80211_freq_range *freq_limits,
     23					 unsigned int n_freq_limits,
     24					 struct ieee80211_channel *chan)
     25{
     26	u32 bw = MHZ_TO_KHZ(20);
     27	int i;
     28
     29	for (i = 0; i < n_freq_limits; i++) {
     30		struct ieee80211_freq_range *limit = &freq_limits[i];
     31
     32		if (cfg80211_does_bw_fit_range(limit,
     33					       MHZ_TO_KHZ(chan->center_freq),
     34					       bw))
     35			return true;
     36	}
     37
     38	return false;
     39}
     40
     41static void wiphy_freq_limits_apply(struct wiphy *wiphy,
     42				    struct ieee80211_freq_range *freq_limits,
     43				    unsigned int n_freq_limits)
     44{
     45	enum nl80211_band band;
     46	int i;
     47
     48	if (WARN_ON(!n_freq_limits))
     49		return;
     50
     51	for (band = 0; band < NUM_NL80211_BANDS; band++) {
     52		struct ieee80211_supported_band *sband = wiphy->bands[band];
     53
     54		if (!sband)
     55			continue;
     56
     57		for (i = 0; i < sband->n_channels; i++) {
     58			struct ieee80211_channel *chan = &sband->channels[i];
     59
     60			if (chan->flags & IEEE80211_CHAN_DISABLED)
     61				continue;
     62
     63			if (!wiphy_freq_limits_valid_chan(wiphy, freq_limits,
     64							  n_freq_limits,
     65							  chan)) {
     66				pr_debug("Disabling freq %d MHz as it's out of OF limits\n",
     67					 chan->center_freq);
     68				chan->flags |= IEEE80211_CHAN_DISABLED;
     69			}
     70		}
     71	}
     72}
     73
     74void wiphy_read_of_freq_limits(struct wiphy *wiphy)
     75{
     76	struct device *dev = wiphy_dev(wiphy);
     77	struct device_node *np;
     78	struct property *prop;
     79	struct ieee80211_freq_range *freq_limits;
     80	unsigned int n_freq_limits;
     81	const __be32 *p;
     82	int len, i;
     83	int err = 0;
     84
     85	if (!dev)
     86		return;
     87	np = dev_of_node(dev);
     88	if (!np)
     89		return;
     90
     91	prop = of_find_property(np, "ieee80211-freq-limit", &len);
     92	if (!prop)
     93		return;
     94
     95	if (!len || len % sizeof(u32) || len / sizeof(u32) % 2) {
     96		dev_err(dev, "ieee80211-freq-limit wrong format");
     97		return;
     98	}
     99	n_freq_limits = len / sizeof(u32) / 2;
    100
    101	freq_limits = kcalloc(n_freq_limits, sizeof(*freq_limits), GFP_KERNEL);
    102	if (!freq_limits) {
    103		err = -ENOMEM;
    104		goto out_kfree;
    105	}
    106
    107	p = NULL;
    108	for (i = 0; i < n_freq_limits; i++) {
    109		struct ieee80211_freq_range *limit = &freq_limits[i];
    110
    111		p = of_prop_next_u32(prop, p, &limit->start_freq_khz);
    112		if (!p) {
    113			err = -EINVAL;
    114			goto out_kfree;
    115		}
    116
    117		p = of_prop_next_u32(prop, p, &limit->end_freq_khz);
    118		if (!p) {
    119			err = -EINVAL;
    120			goto out_kfree;
    121		}
    122
    123		if (!limit->start_freq_khz ||
    124		    !limit->end_freq_khz ||
    125		    limit->start_freq_khz >= limit->end_freq_khz) {
    126			err = -EINVAL;
    127			goto out_kfree;
    128		}
    129	}
    130
    131	wiphy_freq_limits_apply(wiphy, freq_limits, n_freq_limits);
    132
    133out_kfree:
    134	kfree(freq_limits);
    135	if (err)
    136		dev_err(dev, "Failed to get limits: %d\n", err);
    137}
    138EXPORT_SYMBOL(wiphy_read_of_freq_limits);