path: root/net/wireless/chan.c

// SPDX-License-Identifier: GPL-2.0
/*
 * This file contains helper code to handle channel
 * settings and keeping track of what is possible at
 * any point in time.
 *
 * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 * Copyright 2018-2025	Intel Corporation
 */

#include <linux/export.h>
#include <linux/bitfield.h>
#include <net/cfg80211.h>
#include "core.h"
#include "rdev-ops.h"

static bool cfg80211_valid_60g_freq(u32 freq)
{
	return freq >= 58320 && freq <= 70200;
}

void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
			     struct ieee80211_channel *chan,
			     enum nl80211_channel_type chan_type)
{
	if (WARN_ON(!chan))
		return;

	*chandef = (struct cfg80211_chan_def) {
		.chan = chan,
		.freq1_offset = chan->freq_offset,
	};

	switch (chan_type) {
	case NL80211_CHAN_NO_HT:
		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
		chandef->center_freq1 = chan->center_freq;
		break;
	case NL80211_CHAN_HT20:
		chandef->width = NL80211_CHAN_WIDTH_20;
		chandef->center_freq1 = chan->center_freq;
		break;
	case NL80211_CHAN_HT40PLUS:
		chandef->width = NL80211_CHAN_WIDTH_40;
		chandef->center_freq1 = chan->center_freq + 10;
		break;
	case NL80211_CHAN_HT40MINUS:
		chandef->width = NL80211_CHAN_WIDTH_40;
		chandef->center_freq1 = chan->center_freq - 10;
		break;
	default:
		WARN_ON(1);
	}
}
EXPORT_SYMBOL(cfg80211_chandef_create);

static u32 cfg80211_get_start_freq(const struct cfg80211_chan_def *chandef,
				   u32 cf)
{
	u32 start_freq, center_freq, bandwidth;

	center_freq = MHZ_TO_KHZ((cf == 1) ?
			chandef->center_freq1 : chandef->center_freq2);
	bandwidth = MHZ_TO_KHZ(cfg80211_chandef_get_width(chandef));

	if (bandwidth <= MHZ_TO_KHZ(20))
		start_freq = center_freq;
	else
		start_freq = center_freq - bandwidth / 2 + MHZ_TO_KHZ(10);

	return start_freq;
}

static u32 cfg80211_get_end_freq(const struct cfg80211_chan_def *chandef,
				 u32 cf)
{
	u32 end_freq, center_freq, bandwidth;

	center_freq = MHZ_TO_KHZ((cf == 1) ?
			chandef->center_freq1 : chandef->center_freq2);
	bandwidth = MHZ_TO_KHZ(cfg80211_chandef_get_width(chandef));

	if (bandwidth <= MHZ_TO_KHZ(20))
		end_freq = center_freq;
	else
		end_freq = center_freq + bandwidth / 2 - MHZ_TO_KHZ(10);

	return end_freq;
}

#define for_each_subchan(chandef, freq, cf)				\
	for (u32 punctured = chandef->punctured,			\
	     cf = 1, freq = cfg80211_get_start_freq(chandef, cf);	\
	     freq <= cfg80211_get_end_freq(chandef, cf);		\
	     freq += MHZ_TO_KHZ(20),					\
	     ((cf == 1 && chandef->center_freq2 != 0 &&			\
	       freq > cfg80211_get_end_freq(chandef, cf)) ?		\
	      (cf++, freq = cfg80211_get_start_freq(chandef, cf),	\
	       punctured = 0) : (punctured >>= 1)))			\
		if (!(punctured & 1))

struct cfg80211_per_bw_puncturing_values {
	u8 len;
	const u16 *valid_values;
};

static const u16 puncturing_values_80mhz[] = {
	0x8, 0x4, 0x2, 0x1
};

static const u16 puncturing_values_160mhz[] = {
	 0x80, 0x40, 0x20, 0x10, 0x8, 0x4, 0x2, 0x1, 0xc0, 0x30, 0xc, 0x3
};

static const u16 puncturing_values_320mhz[] = {
	0xc000, 0x3000, 0xc00, 0x300, 0xc0, 0x30, 0xc, 0x3, 0xf000, 0xf00,
	0xf0, 0xf, 0xfc00, 0xf300, 0xf0c0, 0xf030, 0xf00c, 0xf003, 0xc00f,
	0x300f, 0xc0f, 0x30f, 0xcf, 0x3f
};

#define CFG80211_PER_BW_VALID_PUNCTURING_VALUES(_bw) \
	{ \
		.len = ARRAY_SIZE(puncturing_values_ ## _bw ## mhz), \
		.valid_values = puncturing_values_ ## _bw ## mhz \
	}

static const struct cfg80211_per_bw_puncturing_values per_bw_puncturing[] = {
	CFG80211_PER_BW_VALID_PUNCTURING_VALUES(80),
	CFG80211_PER_BW_VALID_PUNCTURING_VALUES(160),
	CFG80211_PER_BW_VALID_PUNCTURING_VALUES(320)
};

static bool valid_puncturing_bitmap(const struct cfg80211_chan_def *chandef)
{
	u32 idx, i, start_freq, primary_center = chandef->chan->center_freq;

	switch (chandef->width) {
	case NL80211_CHAN_WIDTH_80:
		idx = 0;
		start_freq = chandef->center_freq1 - 40;
		break;
	case NL80211_CHAN_WIDTH_160:
		idx = 1;
		start_freq = chandef->center_freq1 - 80;
		break;
	case NL80211_CHAN_WIDTH_320:
		idx = 2;
		start_freq = chandef->center_freq1 - 160;
		break;
	default:
		return chandef->punctured == 0;
	}

	if (!chandef->punctured)
		return true;

	/* check if primary channel is punctured */
	if (chandef->punctured & (u16)BIT((primary_center - start_freq) / 20))
		return false;

	for (i = 0; i < per_bw_puncturing[idx].len; i++) {
		if (per_bw_puncturing[idx].valid_values[i] == chandef->punctured)
			return true;
	}

	return false;
}

static bool cfg80211_edmg_chandef_valid(const struct cfg80211_chan_def *chandef)
{
	int max_contiguous = 0;
	int num_of_enabled = 0;
	int contiguous = 0;
	int i;

	if (!chandef->edmg.channels || !chandef->edmg.bw_config)
		return false;

	if (!cfg80211_valid_60g_freq(chandef->chan->center_freq))
		return false;

	for (i = 0; i < 6; i++) {
		if (chandef->edmg.channels & BIT(i)) {
			contiguous++;
			num_of_enabled++;
		} else {
			contiguous = 0;
		}

		max_contiguous = max(contiguous, max_contiguous);
	}
	/* basic verification of edmg configuration according to
	 * IEEE P802.11ay/D4.0 section 9.4.2.251
	 */
	/* check bw_config against contiguous edmg channels */
	switch (chandef->edmg.bw_config) {
	case IEEE80211_EDMG_BW_CONFIG_4:
	case IEEE80211_EDMG_BW_CONFIG_8:
	case IEEE80211_EDMG_BW_CONFIG_12:
		if (max_contiguous < 1)
			return false;
		break;
	case IEEE80211_EDMG_BW_CONFIG_5:
	case IEEE80211_EDMG_BW_CONFIG_9:
	case IEEE80211_EDMG_BW_CONFIG_13:
		if (max_contiguous < 2)
			return false;
		break;
	case IEEE80211_EDMG_BW_CONFIG_6:
	case IEEE80211_EDMG_BW_CONFIG_10:
	case IEEE80211_EDMG_BW_CONFIG_14:
		if (max_contiguous < 3)
			return false;
		break;
	case IEEE80211_EDMG_BW_CONFIG_7:
	case IEEE80211_EDMG_BW_CONFIG_11:
	case IEEE80211_EDMG_BW_CONFIG_15:
		if (max_contiguous < 4)
			return false;
		break;

	default:
		return false;
	}

	/* check bw_config against aggregated (non contiguous) edmg channels */
	switch (chandef->edmg.bw_config) {
	case IEEE80211_EDMG_BW_CONFIG_4:
	case IEEE80211_EDMG_BW_CONFIG_5:
	case IEEE80211_EDMG_BW_CONFIG_6:
	case IEEE80211_EDMG_BW_CONFIG_7:
		break;
	case IEEE80211_EDMG_BW_CONFIG_8:
	case IEEE80211_EDMG_BW_CONFIG_9:
	case IEEE80211_EDMG_BW_CONFIG_10:
	case IEEE80211_EDMG_BW_CONFIG_11:
		if (num_of_enabled < 2)
			return false;
		break;
	case IEEE80211_EDMG_BW_CONFIG_12:
	case IEEE80