path: root/drivers/net/wireless/brcm80211/brcmsmac/ampdu.c

/*
 * Copyright (c) 2010 Broadcom Corporation
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <net/mac80211.h>

#include "rate.h"
#include "scb.h"
#include "phy/phy_hal.h"
#include "antsel.h"
#include "main.h"
#include "ampdu.h"

/* max number of mpdus in an ampdu */
#define AMPDU_MAX_MPDU			32
/* max number of mpdus in an ampdu to a legacy */
#define AMPDU_NUM_MPDU_LEGACY		16
/* max Tx ba window size (in pdu) */
#define AMPDU_TX_BA_MAX_WSIZE		64
/* default Tx ba window size (in pdu) */
#define AMPDU_TX_BA_DEF_WSIZE		64
/* default Rx ba window size (in pdu) */
#define AMPDU_RX_BA_DEF_WSIZE		64
/* max Rx ba window size (in pdu) */
#define AMPDU_RX_BA_MAX_WSIZE		64
/* max dur of tx ampdu (in msec) */
#define	AMPDU_MAX_DUR			5
/* default tx retry limit */
#define AMPDU_DEF_RETRY_LIMIT		5
/* default tx retry limit at reg rate */
#define AMPDU_DEF_RR_RETRY_LIMIT	2
/* default weight of ampdu in txfifo */
#define AMPDU_DEF_TXPKT_WEIGHT		2
/* default ffpld reserved bytes */
#define AMPDU_DEF_FFPLD_RSVD		2048
/* # of inis to be freed on detach */
#define AMPDU_INI_FREE			10
/* max # of mpdus released at a time */
#define	AMPDU_SCB_MAX_RELEASE		20

#define NUM_FFPLD_FIFO 4	/* number of fifo concerned by pre-loading */
#define FFPLD_TX_MAX_UNFL   200	/* default value of the average number of ampdu
				 * without underflows
				 */
#define FFPLD_MPDU_SIZE 1800	/* estimate of maximum mpdu size */
#define FFPLD_MAX_MCS 23	/* we don't deal with mcs 32 */
#define FFPLD_PLD_INCR 1000	/* increments in bytes */
#define FFPLD_MAX_AMPDU_CNT 5000	/* maximum number of ampdu we
					 * accumulate between resets.
					 */

#define AMPDU_DELIMITER_LEN	4

/* max allowed number of mpdus in an ampdu (2 streams) */
#define AMPDU_NUM_MPDU		16

#define TX_SEQ_TO_INDEX(seq) ((seq) % AMPDU_TX_BA_MAX_WSIZE)

/* max possible overhead per mpdu in the ampdu; 3 is for roundup if needed */
#define AMPDU_MAX_MPDU_OVERHEAD (FCS_LEN + DOT11_ICV_AES_LEN +\
	AMPDU_DELIMITER_LEN + 3\
	+ DOT11_A4_HDR_LEN + DOT11_QOS_LEN + DOT11_IV_MAX_LEN)

/* modulo add/sub, bound = 2^k */
#define MODADD_POW2(x, y, bound) (((x) + (y)) & ((bound) - 1))
#define MODSUB_POW2(x, y, bound) (((x) - (y)) & ((bound) - 1))

/* structure to hold tx fifo information and pre-loading state
 * counters specific to tx underflows of ampdus
 * some counters might be redundant with the ones in wlc or ampdu structures.
 * This allows to maintain a specific state independently of
 * how often and/or when the wlc counters are updated.
 *
 * ampdu_pld_size: number of bytes to be pre-loaded
 * mcs2ampdu_table: per-mcs max # of mpdus in an ampdu
 * prev_txfunfl: num of underflows last read from the HW macstats counter
 * accum_txfunfl: num of underflows since we modified pld params
 * accum_txampdu: num of tx ampdu since we modified pld params
 * prev_txampdu: previous reading of tx ampdu
 * dmaxferrate: estimated dma avg xfer rate in kbits/sec
 */
struct brcms_fifo_info {
	u16 ampdu_pld_size;
	u8 mcs2ampdu_table[FFPLD_MAX_MCS + 1];
	u16 prev_txfunfl;
	u32 accum_txfunfl;
	u32 accum_txampdu;
	u32 prev_txampdu;
	u32 dmaxferrate;
};

/* AMPDU module specific state
 *
 * wlc: pointer to main wlc structure
 * scb_handle: scb cubby handle to retrieve data from scb
 * ini_enable: per-tid initiator enable/disable of ampdu
 * ba_tx_wsize: Tx ba window size (in pdu)
 * ba_rx_wsize: Rx ba window size (in pdu)
 * retry_limit: mpdu transmit retry limit
 * rr_retry_limit: mpdu transmit retry limit at regular rate
 * retry_limit_tid: per-tid mpdu transmit retry limit
 * rr_retry_limit_tid: per-tid mpdu transmit retry limit at regular rate
 * mpdu_density: min mpdu spacing (0-7) ==> 2^(x-1)/8 usec
 * max_pdu: max pdus allowed in ampdu
 * dur: max duration of an ampdu (in msec)
 * txpkt_weight: weight of ampdu in txfifo; reduces rate lag
 * rx_factor: maximum rx ampdu factor (0-3) ==> 2^(13+x) bytes
 * ffpld_rsvd: number of bytes to reserve for preload
 * max_txlen: max size of ampdu per mcs, bw and sgi
 * mfbr: enable multiple fallback rate
 * tx_max_funl: underflows should be kept such that
 *		(tx_max_funfl*underflows) < tx frames
 * fifo_tb: table of fifo infos
 */
struct ampdu_info {
	struct brcms_c_info *wlc;
	int scb_handle;
	u8 ini_enable[AMPDU_MAX_SCB_TID];
	u8 ba_tx_wsize;
	u8 ba_rx_wsize;
	u8 retry_limit;
	u8 rr_retry_limit;
	u8 retry_limit_tid[AMPDU_MAX_SCB_TID];
	u8 rr_retry_limit_tid[AMPDU_MAX_SCB_TID];
	u8 mpdu_density;
	s8 max_pdu;
	u8 dur;
	u8 txpkt_weight;
	u8 rx_factor;
	u32 ffpld_rsvd;
	u32 max_txlen[MCS_TABLE_SIZE][2][2];
	bool mfbr;
	u32 tx_max_funl;
	struct brcms_fifo_info fifo_tb[NUM_FFPLD_FIFO];
};

/* used for flushing ampdu packets */
struct cb_del_ampdu_pars {
	struct ieee80211_sta *sta;
	u16 tid;
};

static void brcms_c_scb_ampdu_update_max_txlen(struct ampdu_info *ampdu, u8 dur)
{
	u32 rate, mcs;

	for (mcs<