bcm43xx_xmit.c

博通的bcm43xx系列Minipci接口无线网卡驱动

/*

  Broadcom BCM43xx wireless driver

  Transmission (TX/RX) related functions.

  Copyright (c) 2005 Martin Langer <[e-mail]>,
                     Stefano Brivio <[e-mail]>
                     Michael Buesch <[e-mail]>
                     Danny van Dyk <[e-mail]>
                     Andreas Jaggi <[e-mail]>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; see the file COPYING.  If not, write to
  the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
  Boston, MA 02110-1301, USA.

*/

#include "bcm43xx_xmit.h"

#include <linux/etherdevice.h>


/* Extract the bitrate out of a CCK PLCP header. */
static u8 bcm43xx_plcp_get_bitrate_cck(struct bcm43xx_plcp_hdr4 *plcp)
{
	switch (plcp->raw[0]) {
	case 0x0A:
		return IEEE80211_CCK_RATE_1MB;
	case 0x14:
		return IEEE80211_CCK_RATE_2MB;
	case 0x37:
		return IEEE80211_CCK_RATE_5MB;
	case 0x6E:
		return IEEE80211_CCK_RATE_11MB;
	}
	assert(0);
	return 0;
}

/* Extract the bitrate out of an OFDM PLCP header. */
static u8 bcm43xx_plcp_get_bitrate_ofdm(struct bcm43xx_plcp_hdr4 *plcp)
{
	switch (plcp->raw[0] & 0xF) {
	case 0xB:
		return IEEE80211_OFDM_RATE_6MB;
	case 0xF:
		return IEEE80211_OFDM_RATE_9MB;
	case 0xA:
		return IEEE80211_OFDM_RATE_12MB;
	case 0xE:
		return IEEE80211_OFDM_RATE_18MB;
	case 0x9:
		return IEEE80211_OFDM_RATE_24MB;
	case 0xD:
		return IEEE80211_OFDM_RATE_36MB;
	case 0x8:
		return IEEE80211_OFDM_RATE_48MB;
	case 0xC:
		return IEEE80211_OFDM_RATE_54MB;
	}
	assert(0);
	return 0;
}

u8 bcm43xx_plcp_get_ratecode_cck(const u8 bitrate)
{
	switch (bitrate) {
	case IEEE80211_CCK_RATE_1MB:
		return 0x0A;
	case IEEE80211_CCK_RATE_2MB:
		return 0x14;
	case IEEE80211_CCK_RATE_5MB:
		return 0x37;
	case IEEE80211_CCK_RATE_11MB:
		return 0x6E;
	}
	assert(0);
	return 0;
}

u8 bcm43xx_plcp_get_ratecode_ofdm(const u8 bitrate)
{
	switch (bitrate) {
	case IEEE80211_OFDM_RATE_6MB:
		return 0xB;
	case IEEE80211_OFDM_RATE_9MB:
		return 0xF;
	case IEEE80211_OFDM_RATE_12MB:
		return 0xA;
	case IEEE80211_OFDM_RATE_18MB:
		return 0xE;
	case IEEE80211_OFDM_RATE_24MB:
		return 0x9;
	case IEEE80211_OFDM_RATE_36MB:
		return 0xD;
	case IEEE80211_OFDM_RATE_48MB:
		return 0x8;
	case IEEE80211_OFDM_RATE_54MB:
		return 0xC;
	}
	assert(0);
	return 0;
}

static void bcm43xx_generate_plcp_hdr(struct bcm43xx_plcp_hdr4 *plcp,
				      const u16 octets, const u8 bitrate,
				      const int ofdm_modulation)
{
	__le32 *data = &(plcp->data);
	__u8 *raw = plcp->raw;

	if (ofdm_modulation) {
		*data = bcm43xx_plcp_get_ratecode_ofdm(bitrate);
		assert(!(octets & 0xF000));
		*data |= (octets << 5);
		*data = cpu_to_le32(*data);
	} else {
		u32 plen;

		plen = octets * 16 / bitrate;
		if ((octets * 16 % bitrate) > 0) {
			plen++;
			if ((bitrate == IEEE80211_CCK_RATE_11MB)
			    && ((octets * 8 % 11) < 4)) {
				raw[1] = 0x84;
			} else
				raw[1] = 0x04;
		} else
			raw[1] = 0x04;
		*data |= cpu_to_le32(plen << 16);
		raw[0] = bcm43xx_plcp_get_ratecode_cck(bitrate);
	}
}

static u8 bcm43xx_calc_fallback_rate(u8 bitrate)
{
	switch (bitrate) {
	case IEEE80211_CCK_RATE_1MB:
		return IEEE80211_CCK_RATE_1MB;
	case IEEE80211_CCK_RATE_2MB:
		return IEEE80211_CCK_RATE_1MB;
	case IEEE80211_CCK_RATE_5MB:
		return IEEE80211_CCK_RATE_2MB;
	case IEEE80211_CCK_RATE_11MB:
		return IEEE80211_CCK_RATE_5MB;
	case IEEE80211_OFDM_RATE_6MB:
		return IEEE80211_CCK_RATE_5MB;
	case IEEE80211_OFDM_RATE_9MB:
		return IEEE80211_OFDM_RATE_6MB;
	case IEEE80211_OFDM_RATE_12MB:
		return IEEE80211_OFDM_RATE_9MB;
	case IEEE80211_OFDM_RATE_18MB:
		return IEEE80211_OFDM_RATE_12MB;
	case IEEE80211_OFDM_RATE_24MB:
		return IEEE80211_OFDM_RATE_18MB;
	case IEEE80211_OFDM_RATE_36MB:
		return IEEE80211_OFDM_RATE_24MB;
	case IEEE80211_OFDM_RATE_48MB:
		return IEEE80211_OFDM_RATE_36MB;
	case IEEE80211_OFDM_RATE_54MB:
		return IEEE80211_OFDM_RATE_48MB;
	}
	assert(0);
	return 0;
}

static
__le16 bcm43xx_calc_duration_id(const struct ieee80211_hdr *wireless_header,
				u8 bitrate)
{
	const u16 frame_ctl = le16_to_cpu(wireless_header->frame_ctl);
	__le16 duration_id = wireless_header->duration_id;

	switch (WLAN_FC_GET_TYPE(frame_ctl)) {
	case IEEE80211_FTYPE_DATA:
	case IEEE80211_FTYPE_MGMT:
		//TODO: Steal the code from ieee80211, once it is completed there.
		break;
	case IEEE80211_FTYPE_CTL:
		/* Use the original duration/id. */
		break;
	default:
		assert(0);
	}

	return duration_id;
}

static inline
u16 ceiling_div(u16 dividend, u16 divisor)
{
	return ((dividend + divisor - 1) / divisor);
}

static void bcm43xx_generate_rts(const struct bcm43xx_phyinfo *phy,
				 struct bcm43xx_txhdr *txhdr,
				 u16 *flags,
				 u8 bitrate,
				 const struct ieee80211_hdr_4addr *wlhdr)
{
	u16 fctl;
	u16 dur;
	u8 fallback_bitrate;
	int ofdm_modulation;
	int fallback_ofdm_modulation;
	u8 *sa, *da;
	u16 flen;

//FIXME	sa = ieee80211_get_SA((struct ieee80211_hdr *)wlhdr);
//FIXME	da = ieee80211_get_DA((struct ieee80211_hdr *)wlhdr);
	fallback_bitrate = bcm43xx_calc_fallback_rate(bitrate);
	ofdm_modulation = !(ieee80211_is_cck_rate(bitrate));
	fallback_ofdm_modulation = !(ieee80211_is_cck_rate(fallback_bitrate));

	flen = sizeof(u16) + sizeof(u16) + ETH_ALEN + ETH_ALEN + IEEE80211_FCS_LEN,
	bcm43xx_generate_plcp_hdr((struct bcm43xx_plcp_hdr4 *)(&txhdr->rts_cts_plcp),
				  flen, bitrate,
				  !ieee80211_is_cck_rate(bitrate));
	bcm43xx_generate_plcp_hdr((struct bcm43xx_plcp_hdr4 *)(&txhdr->rts_cts_fallback_plcp),
				  flen, fallback_bitrate,
				  !ieee80211_is_cck_rate(fallback_bitrate));
	fctl = IEEE80211_FTYPE_CTL;
	fctl |= IEEE80211_STYPE_RTS;
	dur = le16_to_cpu(wlhdr->duration_id);
/*FIXME: should we test for dur==0 here and let it unmodified in this case?
 *       The following assert checks for this case...
 */
assert(dur);
/*FIXME: The duration calculation is not really correct.
 *       I am not 100% sure which bitrate to use. We use the RTS rate here,
 *       but this is likely to be wrong.
 */
	if (phy->type == BCM43xx_PHYTYPE_A) {
		/* Three times SIFS */
		dur += 16 * 3;
		/* Add ACK duration. */
		dur += ceiling_div((16 + 8 * (14 /*bytes*/) + 6) * 10,
				   bitrate * 4);
		/* Add CTS duration. */
		dur += ceiling_div((16 + 8 * (14 /*bytes*/) + 6) * 10,
				   bitrate * 4);
	} else {
		/* Three times SIFS */
		dur += 10 * 3;
		/* Add ACK duration. */
		dur += ceiling_div(8 * (14 /*bytes*/) * 10,
				   bitrate);
		/* Add CTS duration. */
		dur += ceiling_div(8 * (14 /*bytes*/) * 10,
				   bitrate);
	}

	txhdr->rts_cts_frame_control = cpu_to_le16(fctl);
	txhdr->rts_cts_dur = cpu_to_le16(dur);
//printk(BCM43xx_MACFMT "  " BCM43xx_MACFMT "  " BCM43xx_MACFMT "\n", BCM43xx_MACARG(wlhdr->addr1), BCM43xx_MACARG(wlhdr->addr2), BCM43xx_MACARG(wlhdr->addr3));
//printk(BCM43xx_MACFMT "  " BCM43xx_MACFMT "\n", BCM43xx_MACARG(sa), BCM43xx_MACARG(da));
	memcpy(txhdr->rts_cts_mac1, wlhdr->addr1, ETH_ALEN);//FIXME!
	memcpy(txhdr->rts_cts_mac2, sa, ETH_ALEN);

	*flags |= BCM43xx_TXHDRFLAG_RTSCTS;
	*flags |= BCM43xx_TXHDRFLAG_RTS;
	if (ofdm_modulation)
		*flags |= BCM43xx_TXHDRFLAG_RTSCTS_OFDM;
	if (fallback_ofdm_modulation)
		*flags |= BCM43xx_TXHDRFLAG_RTSCTSFALLBACK_OFDM;
}
				 
void bcm43xx_generate_txhdr(struct bcm43xx_private *bcm,
			    struct bcm43xx_txhdr *txhdr,
			    const unsigned char *fragment_data,
			    const unsigned int fragment_len,
			    const int is_first_fragment,
			    const u16 cookie)
{
	const struct bcm43xx_phyinfo *phy = bcm->current_core->phy;
	const struct ieee80211_hdr_4addr *wireless_header = (const struct ieee80211_hdr_4addr *)fragment_data;
	const struct ieee80211_security *secinfo = &bcm->ieee->sec;
	u8 bitrate;