mac80211: add the 'minstrel' rate control algorithm

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/Kconfig

@@ -22,6 +22,11 @@ config MAC80211_RC_PID
 	  mac80211 that uses a PID controller to select the TX
 	  rate.
 
+config MAC80211_RC_MINSTREL
+	bool "Minstrel"
+	---help---
+	  This option enables the 'minstrel' TX rate control algorithm
+
 choice
 	prompt "Default rate control algorithm"
 	default MAC80211_RC_DEFAULT_PID
@@ -39,11 +44,19 @@ config MAC80211_RC_DEFAULT_PID
 	  default rate control algorithm. You should choose
 	  this unless you know what you are doing.
 
+config MAC80211_RC_DEFAULT_MINSTREL
+	bool "Minstrel"
+	depends on MAC80211_RC_MINSTREL
+	---help---
+	  Select Minstrel as the default rate control algorithm.
+
+
 endchoice
 
 config MAC80211_RC_DEFAULT
 	string
 	default "pid" if MAC80211_RC_DEFAULT_PID
+	default "minstrel" if MAC80211_RC_DEFAULT_MINSTREL
 	default ""
 
 endmenu

net/mac80211/Makefile

@@ -41,4 +41,8 @@ mac80211-$(CONFIG_MAC80211_MESH) += \
 rc80211_pid-y := rc80211_pid_algo.o
 rc80211_pid-$(CONFIG_MAC80211_DEBUGFS) += rc80211_pid_debugfs.o
 
+rc80211_minstrel-y := rc80211_minstrel.o
+rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += rc80211_minstrel_debugfs.o
+
 mac80211-$(CONFIG_MAC80211_RC_PID) += $(rc80211_pid-y)
+mac80211-$(CONFIG_MAC80211_RC_MINSTREL) += $(rc80211_minstrel-y)

net/mac80211/main.c

@@ -1015,6 +1015,10 @@ static int __init ieee80211_init(void)
 	BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, driver_data) +
 	             IEEE80211_TX_INFO_DRIVER_DATA_SIZE > sizeof(skb->cb));
 
+	ret = rc80211_minstrel_init();
+	if (ret)
+		return ret;
+
 	ret = rc80211_pid_init();
 	if (ret)
 		return ret;
@@ -1027,6 +1031,7 @@ static int __init ieee80211_init(void)
 static void __exit ieee80211_exit(void)
 {
 	rc80211_pid_exit();
+	rc80211_minstrel_exit();
 
 	/*
 	 * For key todo, it'll be empty by now but the work

net/mac80211/rate.h

@@ -125,4 +125,18 @@ static inline void rc80211_pid_exit(void)
 }
 #endif
 
+#ifdef CONFIG_MAC80211_RC_MINSTREL
+extern int rc80211_minstrel_init(void);
+extern void rc80211_minstrel_exit(void);
+#else
+static inline int rc80211_minstrel_init(void)
+{
+	return 0;
+}
+static inline void rc80211_minstrel_exit(void)
+{
+}
+#endif
+
+
 #endif /* IEEE80211_RATE_H */

net/mac80211/rc80211_minstrel.h

+/*
+ * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
+ *
+ * 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.
+ */
+
+#ifndef __RC_MINSTREL_H
+#define __RC_MINSTREL_H
+
+struct minstrel_rate {
+	int bitrate;
+	int rix;
+
+	unsigned int perfect_tx_time;
+	unsigned int ack_time;
+
+	unsigned int retry_count;
+	unsigned int retry_count_cts;
+	unsigned int retry_count_rtscts;
+	unsigned int adjusted_retry_count;
+
+	u32 success;
+	u32 attempts;
+	u32 last_attempts;
+	u32 last_success;
+
+	/* parts per thousand */
+	u32 cur_prob;
+	u32 probability;
+
+	/* per-rate throughput */
+	u32 cur_tp;
+	u32 throughput;
+
+	u64 succ_hist;
+	u64 att_hist;
+};
+
+struct minstrel_sta_info {
+	unsigned long stats_update;
+	unsigned int sp_ack_dur;
+	unsigned int rate_avg;
+
+	unsigned int lowest_rix;
+
+	unsigned int max_tp_rate;
+	unsigned int max_tp_rate2;
+	unsigned int max_prob_rate;
+	unsigned int packet_count;
+	unsigned int sample_count;
+	int sample_deferred;
+
+	unsigned int sample_idx;
+	unsigned int sample_column;
+
+	int n_rates;
+	struct minstrel_rate *r;
+
+	/* sampling table */
+	u8 *sample_table;
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+	struct dentry *dbg_stats;
+#endif
+};
+
+struct minstrel_priv {
+	struct ieee80211_hw *hw;
+	bool has_mrr;
+	unsigned int cw_min;
+	unsigned int cw_max;
+	unsigned int max_retry;
+	unsigned int ewma_level;
+	unsigned int segment_size;
+	unsigned int update_interval;
+	unsigned int lookaround_rate;
+	unsigned int lookaround_rate_mrr;
+};
+
+void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
+void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
+
+#endif

net/mac80211/rc80211_minstrel_debugfs.c

+/*
+ * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
+ *
+ * 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.
+ *
+ * Based on minstrel.c:
+ *   Copyright (C) 2005-2007 Derek Smithies <derek@indranet.co.nz>
+ *   Sponsored by Indranet Technologies Ltd
+ *
+ * Based on sample.c:
+ *   Copyright (c) 2005 John Bicket
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer,
+ *      without modification.
+ *   2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *      similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
+ *      redistribution must be conditioned upon including a substantially
+ *      similar Disclaimer requirement for further binary redistribution.
+ *   3. Neither the names of the above-listed copyright holders nor the names
+ *      of any contributors may be used to endorse or promote products derived
+ *      from this software without specific prior written permission.
+ *
+ *   Alternatively, this software may be distributed under the terms of the
+ *   GNU General Public License ("GPL") version 2 as published by the Free
+ *   Software Foundation.
+ *
+ *   NO WARRANTY
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
+ *   AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ *   THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
+ *   OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ *   IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ *   THE POSSIBILITY OF SUCH DAMAGES.
+ */
+#include <linux/netdevice.h>
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <linux/debugfs.h>
+#include <linux/ieee80211.h>
+#include <net/mac80211.h>
+#include "rc80211_minstrel.h"
+
+struct minstrel_stats_info {
+	struct minstrel_sta_info *mi;
+	char buf[4096];
+	size_t len;
+};
+
+static int
+minstrel_stats_open(struct inode *inode, struct file *file)
+{
+	struct minstrel_sta_info *mi = inode->i_private;
+	struct minstrel_stats_info *ms;
+	unsigned int i, tp, prob, eprob;
+	char *p;
+
+	ms = kmalloc(sizeof(*ms), GFP_KERNEL);
+	if (!ms)
+		return -ENOMEM;
+
+	file->private_data = ms;
+	p = ms->buf;
+	p += sprintf(p, "rate     throughput  ewma prob   this prob  "
+			"this succ/attempt   success    attempts\n");
+	for (i = 0; i < mi->n_rates; i++) {
+		struct minstrel_rate *mr = &mi->r[i];
+
+		*(p++) = (i == mi->max_tp_rate) ? 'T' : ' ';
+		*(p++) = (i == mi->max_tp_rate2) ? 't' : ' ';
+		*(p++) = (i == mi->max_prob_rate) ? 'P' : ' ';
+		p += sprintf(p, "%3u%s", mr->bitrate / 2,
+				(mr->bitrate & 1 ? ".5" : "  "));
+
+		tp = ((mr->cur_tp * 96) / 18000) >> 10;
+		prob = mr->cur_prob / 18;
+		eprob = mr->probability / 18;
+
+		p += sprintf(p, "  %6u.%1u   %6u.%1u   %6u.%1u        "
+				"%3u(%3u)   %8llu    %8llu\n",
+				tp / 10, tp % 10,
+				eprob / 10, eprob % 10,
+				prob / 10, prob % 10,
+				mr->last_success,
+				mr->last_attempts,
+				mr->succ_hist,
+				mr->att_hist);
+	}
+	p += sprintf(p, "\nTotal packet count::    ideal %d      "
+			"lookaround %d\n\n",
+			mi->packet_count - mi->sample_count,
+			mi->sample_count);
+	ms->len = p - ms->buf;
+
+	return 0;
+}
+
+static int
+minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *o)
+{
+	struct minstrel_stats_info *ms;
+	char *src;
+
+	ms = file->private_data;
+	src = ms->buf;
+
+	len = min(len, ms->len);
+	if (len <= *o)
+		return 0;
+
+	src += *o;
+	len -= *o;
+	*o += len;
+
+	if (copy_to_user(buf, src, len))
+		return -EFAULT;
+
+	return len;
+}
+
+static int
+minstrel_stats_release(struct inode *inode, struct file *file)
+{
+	struct minstrel_stats_info *ms = file->private_data;
+
+	kfree(ms);
+
+	return 0;
+}
+
+static struct file_operations minstrel_stat_fops = {
+	.owner = THIS_MODULE,
+	.open = minstrel_stats_open,
+	.read = minstrel_stats_read,
+	.release = minstrel_stats_release,
+};
+
+void
+minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir)
+{
+	struct minstrel_sta_info *mi = priv_sta;
+
+	mi->dbg_stats = debugfs_create_file("rc_stats", S_IRUGO, dir, mi,
+			&minstrel_stat_fops);
+}
+
+void
+minstrel_remove_sta_debugfs(void *priv, void *priv_sta)
+{
+	struct minstrel_sta_info *mi = priv_sta;
+
+	debugfs_remove(mi->dbg_stats);
+}