cfg80211 API for channels/bitrates, mac80211 and driver conversion

This patch creates new cfg80211 wiphy API for channel and bitrate
registration and converts mac80211 and drivers to the new API. The
old mac80211 API is completely ripped out. All drivers (except ath5k)
are updated to the new API, in many cases I expect that optimisations
can be done.

Along with the regulatory code I've also ripped out the
IEEE80211_HW_DEFAULT_REG_DOMAIN_CONFIGURED flag, I believe it to be
unnecessary if the hardware simply gives us whatever channels it wants
to support and we then enable/disable them as required, which is pretty
much required for travelling.

Additionally, the patch adds proper "basic" rate handling for STA
mode interface, AP mode interface will have to have new API added
to allow userspace to set the basic rate set, currently it'll be
empty... However, the basic rate handling will need to be moved to
the BSS conf stuff.

I do expect there to be bugs in this, especially wrt. transmit
power handling where I'm basically clueless about how it should work.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 153 insertions, 0 deletions

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
new file mode 100644
index 000000000000..2b63c96dcf19
--- /dev/null
+++ b/net/wireless/reg.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005-2006, Devicescape Software, Inc.
+ * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This regulatory domain control implementation is highly incomplete, it
+ * only exists for the purpose of not regressing mac80211.
+ *
+ * For now, drivers can restrict the set of allowed channels by either
+ * not registering those channels or setting the IEEE80211_CHAN_DISABLED
+ * flag; that flag will only be *set* by this code, never *cleared.
+ *
+ * The usual implementation is for a driver to read a device EEPROM to
+ * determine which regulatory domain it should be operating under, then
+ * looking up the allowable channels in a driver-local table and finally
+ * registering those channels in the wiphy structure.
+ *
+ * Alternatively, drivers that trust the regulatory domain control here
+ * will register a complete set of capabilities and the control code
+ * will restrict the set by setting the IEEE80211_CHAN_* flags.
+ */
+#include <linux/kernel.h>
+#include <net/wireless.h>
+#include "core.h"
+
+static char *ieee80211_regdom = "US";
+module_param(ieee80211_regdom, charp, 0444);
+MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");
+
+struct ieee80211_channel_range {
+	short start_freq;
+	short end_freq;
+	int max_power;
+	int max_antenna_gain;
+	u32 flags;
+};
+
+struct ieee80211_regdomain {
+	const char *code;
+	const struct ieee80211_channel_range *ranges;
+	int n_ranges;
+};
+
+#define RANGE_PWR(_start, _end, _pwr, _ag, _flags)	\
+	{ _start, _end, _pwr, _ag, _flags }
+
+
+/*
+ * Ideally, in the future, these definitions will be loaded from a
+ * userspace table via some daemon.
+ */
+static const struct ieee80211_channel_range ieee80211_US_channels[] = {
+	/* IEEE 802.11b/g, channels 1..11 */
+	RANGE_PWR(2412, 2462, 27, 6, 0),
+	/* IEEE 802.11a, channels 52..64 */
+	RANGE_PWR(5260, 5320, 23, 6, 0),
+	/* IEEE 802.11a, channels 149..165, outdoor */
+	RANGE_PWR(5745, 5825, 30, 6, 0),
+};
+
+static const struct ieee80211_channel_range ieee80211_JP_channels[] = {
+	/* IEEE 802.11b/g, channels 1..14 */
+	RANGE_PWR(2412, 2484, 20, 6, 0),
+	/* IEEE 802.11a, channels 34..48 */
+	RANGE_PWR(5170, 5240, 20, 6, IEEE80211_CHAN_PASSIVE_SCAN),
+	/* IEEE 802.11a, channels 52..64 */
+	RANGE_PWR(5260, 5320, 20, 6, IEEE80211_CHAN_NO_IBSS |
+				     IEEE80211_CHAN_RADAR),
+};
+
+#define REGDOM(_code)							\
+	{								\
+		.code = __stringify(_code),				\
+		.ranges = ieee80211_ ##_code## _channels,		\
+		.n_ranges = ARRAY_SIZE(ieee80211_ ##_code## _channels),	\
+	}
+
+static const struct ieee80211_regdomain ieee80211_regdoms[] = {
+	REGDOM(US),
+	REGDOM(JP),
+};
+
+
+static const struct ieee80211_regdomain *get_regdom(void)
+{
+	static const struct ieee80211_channel_range
+	ieee80211_world_channels[] = {
+		/* IEEE 802.11b/g, channels 1..11 */
+		RANGE_PWR(2412, 2462, 27, 6, 0),
+	};
+	static const struct ieee80211_regdomain regdom_world = REGDOM(world);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ieee80211_regdoms); i++)
+		if (strcmp(ieee80211_regdom, ieee80211_regdoms[i].code) == 0)
+			return &ieee80211_regdoms[i];
+
+	return &regdom_world;
+}
+
+
+static void handle_channel(struct ieee80211_channel *chan,
+			   const struct ieee80211_regdomain *rd)
+{
+	int i;
+	u32 flags = chan->orig_flags;
+	const struct ieee80211_channel_range *rg = NULL;
+
+	for (i = 0; i < rd->n_ranges; i++) {
+		if (rd->ranges[i].start_freq <= chan->center_freq &&
+		    chan->center_freq <= rd->ranges[i].end_freq) {
+			rg = &rd->ranges[i];
+			break;
+		}
+	}
+
+	if (!rg) {
+		/* not found */
+		flags |= IEEE80211_CHAN_DISABLED;
+		chan->flags = flags;
+		return;
+	}
+
+	chan->flags = flags;
+	chan->max_antenna_gain = min(chan->orig_mag,
+					 rg->max_antenna_gain);
+	chan->max_power = min(chan->orig_mpwr, rg->max_power);
+}
+
+static void handle_band(struct ieee80211_supported_band *sband,
+			const struct ieee80211_regdomain *rd)
+{
+	int i;
+
+	for (i = 0; i < sband->n_channels; i++)
+		handle_channel(&sband->channels[i], rd);
+}
+
+void wiphy_update_regulatory(struct wiphy *wiphy)
+{
+	enum ieee80211_band band;
+	const struct ieee80211_regdomain *rd = get_regdom();
+
+	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
+		if (wiphy->bands[band])
+			handle_band(wiphy->bands[band], rd);
+}