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wifi: cfg80211: simplify cfg80211_chandef_compatible()

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Simplify cfg80211_chandef_compatible() a bit by switching
c1 and c2 around so that c1 is always the narrower one
(once they're not identical or narrow/S1G). Then we can
just check the various primary channels and exit with the
wider one (c2), or NULL.

Also refactor the primary 40/80/160 function to not have
all the calculations hard-coded, and use a wrapper around
it to check primary 40/80/160 compatibility.

While at it, add some kunit tests for this functionality.

Also expose the new cfg80211_chandef_primary_freq() to
drivers, mac80211 will use it.

Link: https://msgid.link/20240129194108.be3e6eccaba3.I8399c2ff1435d7378e5837794cb5aa6dd2ee1416@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Johannes Berg 2024-01-29 19:34:47 +01:00
parent b9d908dc3a
commit 8f251a0a15
4 changed files with 294 additions and 91 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
include/net/cfg80211.h
View File

@ -1047,6 +1047,17 @@ unsigned int
cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
const struct cfg80211_chan_def *chandef);
/**
* cfg80211_chandef_primary_freq - calculate primary 40/80/160 MHz freq
* @chandef: chandef to calculate for
* @primary_chan_width: primary channel width to calculate center for
*
* Returns: the primary 40/80/160 MHz channel center frequency, or -1
* for errors
*/
int cfg80211_chandef_primary_freq(const struct cfg80211_chan_def *chandef,
enum nl80211_chan_width primary_chan_width);
/**
* nl80211_send_chandef - sends the channel definition.
* @msg: the msg to send channel definition

188
net/wireless/chan.c
View File

@ -390,68 +390,60 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
}
EXPORT_SYMBOL(cfg80211_chandef_valid);
static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
u32 *pri40, u32 *pri80, u32 *pri160)
int cfg80211_chandef_primary_freq(const struct cfg80211_chan_def *c,
enum nl80211_chan_width primary_chan_width)
{
int tmp;
int pri_width = nl80211_chan_width_to_mhz(primary_chan_width);
int width = cfg80211_chandef_get_width(c);
u32 control = c->chan->center_freq;
u32 center = c->center_freq1;
switch (c->width) {
case NL80211_CHAN_WIDTH_40:
*pri40 = c->center_freq1;
*pri80 = 0;
*pri160 = 0;
break;
case NL80211_CHAN_WIDTH_80:
case NL80211_CHAN_WIDTH_80P80:
*pri160 = 0;
*pri80 = c->center_freq1;
/* n_P20 */
tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
/* n_P40 */
tmp /= 2;
/* freq_P40 */
*pri40 = c->center_freq1 - 20 + 40 * tmp;
break;
case NL80211_CHAN_WIDTH_160:
*pri160 = c->center_freq1;
/* n_P20 */
tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
/* n_P40 */
tmp /= 2;
/* freq_P40 */
*pri40 = c->center_freq1 - 60 + 40 * tmp;
/* n_P80 */
tmp /= 2;
*pri80 = c->center_freq1 - 40 + 80 * tmp;
break;
case NL80211_CHAN_WIDTH_320:
/* n_P20 */
tmp = (150 + c->chan->center_freq - c->center_freq1) / 20;
/* n_P40 */
tmp /= 2;
/* freq_P40 */
*pri40 = c->center_freq1 - 140 + 40 * tmp;
/* n_P80 */
tmp /= 2;
*pri80 = c->center_freq1 - 120 + 80 * tmp;
/* n_P160 */
tmp /= 2;
*pri160 = c->center_freq1 - 80 + 160 * tmp;
break;
default:
WARN_ON_ONCE(1);
}
if (WARN_ON_ONCE(pri_width < 0 || width < 0))
return -1;
/* not intended to be called this way, can't determine */
if (WARN_ON_ONCE(pri_width > width))
return -1;
while (width > pri_width) {
if (control > center)
center += width / 4;
else
center -= width / 4;
width /= 2;
}
const struct cfg80211_chan_def *
cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
return center;
}
EXPORT_SYMBOL(cfg80211_chandef_primary_freq);
static const struct cfg80211_chan_def *
check_chandef_primary_compat(const struct cfg80211_chan_def *c1,
const struct cfg80211_chan_def *c2,
enum nl80211_chan_width primary_chan_width)
{
/* check primary is compatible -> error if not */
if (cfg80211_chandef_primary_freq(c1, primary_chan_width) !=
cfg80211_chandef_primary_freq(c2, primary_chan_width))
return ERR_PTR(-EINVAL);
/* assumes c1 is smaller width, if that was just checked -> done */
if (c1->width == primary_chan_width)
return c2;
/* otherwise continue checking the next width */
return NULL;
}
static const struct cfg80211_chan_def *
_cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
const struct cfg80211_chan_def *c2)
{
u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80, c1_pri160, c2_pri160;
const struct cfg80211_chan_def *ret;
/* If they are identical, return */
if (cfg80211_chandef_identical(c1, c2))
return c1;
return c2;
/* otherwise, must have same control channel */
if (c1->chan != c2->chan)
@ -479,44 +471,62 @@ cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
if (NARROW_OR_S1G(c1->width) || NARROW_OR_S1G(c2->width))
return NULL;
if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
c1->width == NL80211_CHAN_WIDTH_20)
return c2;
if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
c2->width == NL80211_CHAN_WIDTH_20)
return c1;
chandef_primary_freqs(c1, &c1_pri40, &c1_pri80, &c1_pri160);
chandef_primary_freqs(c2, &c2_pri40, &c2_pri80, &c2_pri160);
if (c1_pri40 != c2_pri40)
return NULL;
if (c1->width == NL80211_CHAN_WIDTH_40)
return c2;
if (c2->width == NL80211_CHAN_WIDTH_40)
return c1;
if (c1_pri80 != c2_pri80)
return NULL;
if (c1->width == NL80211_CHAN_WIDTH_80 &&
c2->width > NL80211_CHAN_WIDTH_80)
return c2;
if (c2->width == NL80211_CHAN_WIDTH_80 &&
c1->width > NL80211_CHAN_WIDTH_80)
return c1;
WARN_ON(!c1_pri160 && !c2_pri160);
if (c1_pri160 && c2_pri160 && c1_pri160 != c2_pri160)
return NULL;
/*
* Make sure that c1 is always the narrower one, so that later
* we either return NULL or c2 and don't have to check both
* directions.
*/
if (c1->width > c2->width)
return c1;
swap(c1, c2);
/*
* No further checks needed if the "narrower" one is only 20 MHz.
* Here "narrower" includes being a 20 MHz non-HT channel vs. a
* 20 MHz HT (or later) one.
*/
if (c1->width <= NL80211_CHAN_WIDTH_20)
return c2;
ret = check_chandef_primary_compat(c1, c2, NL80211_CHAN_WIDTH_40);
if (ret)
return ret;
ret = check_chandef_primary_compat(c1, c2, NL80211_CHAN_WIDTH_80);
if (ret)
return ret;
/*
* If c1 is 80+80, then c2 is 160 or higher, but that cannot
* match. If c2 was also 80+80 it was already either accepted
* or rejected above (identical or not, respectively.)
*/
if (c1->width == NL80211_CHAN_WIDTH_80P80)
return NULL;
ret = check_chandef_primary_compat(c1, c2, NL80211_CHAN_WIDTH_160);
if (ret)
return ret;
/*
* Getting here would mean they're both wider than 160, have the
* same primary 160, but are not identical - this cannot happen
* since they must be 320 (no wider chandefs exist, at least yet.)
*/
WARN_ON_ONCE(1);
return NULL;
}
const struct cfg80211_chan_def *
cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
const struct cfg80211_chan_def *c2)
{
const struct cfg80211_chan_def *ret;
ret = _cfg80211_chandef_compatible(c1, c2);
if (IS_ERR(ret))
return NULL;
return ret;
}
EXPORT_SYMBOL(cfg80211_chandef_compatible);

2
net/wireless/tests/Makefile
View File

@ -1,3 +1,3 @@
cfg80211-tests-y += module.o fragmentation.o scan.o util.o
cfg80211-tests-y += module.o fragmentation.o scan.o util.o chan.o
obj-$(CONFIG_CFG80211_KUNIT_TEST) += cfg80211-tests.o

182
net/wireless/tests/chan.c Normal file
View File

@ -0,0 +1,182 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* KUnit tests for channel helper functions
*
* Copyright (C) 2023 Intel Corporation
*/
#include <net/cfg80211.h>
#include <kunit/test.h>
MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING);
static struct ieee80211_channel chan_6ghz_1 = {
.band = NL80211_BAND_6GHZ,
.center_freq = 5955,
};
static struct ieee80211_channel chan_6ghz_5 = {
.band = NL80211_BAND_6GHZ,
.center_freq = 5975,
};
static struct ieee80211_channel chan_6ghz_105 = {
.band = NL80211_BAND_6GHZ,
.center_freq = 6475,
};
static const struct chandef_compat_case {
const char *desc;
/* leave c1 empty for tests for identical */
struct cfg80211_chan_def c1, c2;
/* we test both ways around, so c2 should always be the compat one */
bool compat;
} chandef_compat_cases[] = {
{
.desc = "identical non-HT",
.c2 = {
.width = NL80211_CHAN_WIDTH_20_NOHT,
.chan = &chan_6ghz_1,
.center_freq1 = 5955,
},
.compat = true,
},
{
.desc = "identical 20 MHz",
.c2 = {
.width = NL80211_CHAN_WIDTH_20,
.chan = &chan_6ghz_1,
.center_freq1 = 5955,
},
.compat = true,
},
{
.desc = "identical 40 MHz",
.c2 = {
.width = NL80211_CHAN_WIDTH_40,
.chan = &chan_6ghz_1,
.center_freq1 = 5955 + 10,
},
.compat = true,
},
{
.desc = "identical 80 MHz",
.c2 = {
.width = NL80211_CHAN_WIDTH_80,
.chan = &chan_6ghz_1,
.center_freq1 = 5955 + 10 + 20,
},
.compat = true,
},
{
.desc = "identical 160 MHz",
.c2 = {
.width = NL80211_CHAN_WIDTH_160,
.chan = &chan_6ghz_1,
.center_freq1 = 5955 + 10 + 20 + 40,
},
.compat = true,
},
{
.desc = "identical 320 MHz",
.c2 = {
.width = NL80211_CHAN_WIDTH_320,
.chan = &chan_6ghz_1,
.center_freq1 = 5955 + 10 + 20 + 40 + 80,
},
.compat = true,
},
{
.desc = "20 MHz in 320 MHz\n",
.c1 = {
.width = NL80211_CHAN_WIDTH_20,
.chan = &chan_6ghz_1,
.center_freq1 = 5955,
},
.c2 = {
.width = NL80211_CHAN_WIDTH_320,
.chan = &chan_6ghz_1,
.center_freq1 = 5955 + 10 + 20 + 40 + 80,
},
.compat = true,
},
{
.desc = "different 20 MHz",
.c1 = {
.width = NL80211_CHAN_WIDTH_20,
.chan = &chan_6ghz_1,
.center_freq1 = 5955,
},
.c2 = {
.width = NL80211_CHAN_WIDTH_20,
.chan = &chan_6ghz_5,
.center_freq1 = 5975,
},
},
{
.desc = "different primary 160 MHz",
.c1 = {
.width = NL80211_CHAN_WIDTH_320,
.chan = &chan_6ghz_105,
.center_freq1 = 6475 + 150,
},
.c2 = {
.width = NL80211_CHAN_WIDTH_320,
.chan = &chan_6ghz_105,
.center_freq1 = 6475 - 10,
},
},
{
/* similar to previous test but one has lower BW */
.desc = "matching primary 160 MHz",
.c1 = {
.width = NL80211_CHAN_WIDTH_160,
.chan = &chan_6ghz_105,
.center_freq1 = 6475 + 70,
},
.c2 = {
.width = NL80211_CHAN_WIDTH_320,
.chan = &chan_6ghz_105,
.center_freq1 = 6475 - 10,
},
.compat = true,
},
};
KUNIT_ARRAY_PARAM_DESC(chandef_compat, chandef_compat_cases, desc)
static void test_chandef_compat(struct kunit *test)
{
const struct chandef_compat_case *params = test->param_value;
const struct cfg80211_chan_def *ret, *expect;
struct cfg80211_chan_def c1 = params->c1;
/* tests with identical ones */
if (!params->c1.chan)
c1 = params->c2;
KUNIT_EXPECT_EQ(test, cfg80211_chandef_valid(&c1), true);
KUNIT_EXPECT_EQ(test, cfg80211_chandef_valid(&params->c2), true);
expect = params->compat ? &params->c2 : NULL;
ret = cfg80211_chandef_compatible(&c1, &params->c2);
KUNIT_EXPECT_PTR_EQ(test, ret, expect);
if (!params->c1.chan)
expect = &c1;
ret = cfg80211_chandef_compatible(&params->c2, &c1);
KUNIT_EXPECT_PTR_EQ(test, ret, expect);
}
static struct kunit_case chandef_compat_test_cases[] = {
KUNIT_CASE_PARAM(test_chandef_compat, chandef_compat_gen_params),
{}
};
static struct kunit_suite chandef_compat = {
.name = "cfg80211-chandef-compat",
.test_cases = chandef_compat_test_cases,
};
kunit_test_suite(chandef_compat);