xmit.c

linux内核源码

/*

  Broadcom B43legacy wireless driver

  Transmission (TX/RX) related functions.

  Copyright (C) 2005 Martin Langer <[e-mail]>
  Copyright (C) 2005 Stefano Brivio <[e-mail]>
  Copyright (C) 2005, 2006 Michael Buesch <[e-mail]>
  Copyright (C) 2005 Danny van Dyk <[e-mail]>
  Copyright (C) 2005 Andreas Jaggi <[e-mail]>
  Copyright (C) 2007 Larry Finger <[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 <net/dst.h>

#include "xmit.h"
#include "phy.h"
#include "dma.h"
#include "pio.h"


/* Extract the bitrate out of a CCK PLCP header. */
static u8 b43legacy_plcp_get_bitrate_cck(struct b43legacy_plcp_hdr6 *plcp)
{
	switch (plcp->raw[0]) {
	case 0x0A:
		return B43legacy_CCK_RATE_1MB;
	case 0x14:
		return B43legacy_CCK_RATE_2MB;
	case 0x37:
		return B43legacy_CCK_RATE_5MB;
	case 0x6E:
		return B43legacy_CCK_RATE_11MB;
	}
	B43legacy_BUG_ON(1);
	return 0;
}

/* Extract the bitrate out of an OFDM PLCP header. */
static u8 b43legacy_plcp_get_bitrate_ofdm(struct b43legacy_plcp_hdr6 *plcp)
{
	switch (plcp->raw[0] & 0xF) {
	case 0xB:
		return B43legacy_OFDM_RATE_6MB;
	case 0xF:
		return B43legacy_OFDM_RATE_9MB;
	case 0xA:
		return B43legacy_OFDM_RATE_12MB;
	case 0xE:
		return B43legacy_OFDM_RATE_18MB;
	case 0x9:
		return B43legacy_OFDM_RATE_24MB;
	case 0xD:
		return B43legacy_OFDM_RATE_36MB;
	case 0x8:
		return B43legacy_OFDM_RATE_48MB;
	case 0xC:
		return B43legacy_OFDM_RATE_54MB;
	}
	B43legacy_BUG_ON(1);
	return 0;
}

u8 b43legacy_plcp_get_ratecode_cck(const u8 bitrate)
{
	switch (bitrate) {
	case B43legacy_CCK_RATE_1MB:
		return 0x0A;
	case B43legacy_CCK_RATE_2MB:
		return 0x14;
	case B43legacy_CCK_RATE_5MB:
		return 0x37;
	case B43legacy_CCK_RATE_11MB:
		return 0x6E;
	}
	B43legacy_BUG_ON(1);
	return 0;
}

u8 b43legacy_plcp_get_ratecode_ofdm(const u8 bitrate)
{
	switch (bitrate) {
	case B43legacy_OFDM_RATE_6MB:
		return 0xB;
	case B43legacy_OFDM_RATE_9MB:
		return 0xF;
	case B43legacy_OFDM_RATE_12MB:
		return 0xA;
	case B43legacy_OFDM_RATE_18MB:
		return 0xE;
	case B43legacy_OFDM_RATE_24MB:
		return 0x9;
	case B43legacy_OFDM_RATE_36MB:
		return 0xD;
	case B43legacy_OFDM_RATE_48MB:
		return 0x8;
	case B43legacy_OFDM_RATE_54MB:
		return 0xC;
	}
	B43legacy_BUG_ON(1);
	return 0;
}

void b43legacy_generate_plcp_hdr(struct b43legacy_plcp_hdr4 *plcp,
				 const u16 octets, const u8 bitrate)
{
	__le32 *data = &(plcp->data);
	__u8 *raw = plcp->raw;

	if (b43legacy_is_ofdm_rate(bitrate)) {
		u16 d;

		d = b43legacy_plcp_get_ratecode_ofdm(bitrate);
		B43legacy_WARN_ON(octets & 0xF000);
		d |= (octets << 5);
		*data = cpu_to_le32(d);
	} else {
		u32 plen;

		plen = octets * 16 / bitrate;
		if ((octets * 16 % bitrate) > 0) {
			plen++;
			if ((bitrate == B43legacy_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] = b43legacy_plcp_get_ratecode_cck(bitrate);
	}
}

static u8 b43legacy_calc_fallback_rate(u8 bitrate)
{
	switch (bitrate) {
	case B43legacy_CCK_RATE_1MB:
		return B43legacy_CCK_RATE_1MB;
	case B43legacy_CCK_RATE_2MB:
		return B43legacy_CCK_RATE_1MB;
	case B43legacy_CCK_RATE_5MB:
		return B43legacy_CCK_RATE_2MB;
	case B43legacy_CCK_RATE_11MB:
		return B43legacy_CCK_RATE_5MB;
	case B43legacy_OFDM_RATE_6MB:
		return B43legacy_CCK_RATE_5MB;
	case B43legacy_OFDM_RATE_9MB:
		return B43legacy_OFDM_RATE_6MB;
	case B43legacy_OFDM_RATE_12MB:
		return B43legacy_OFDM_RATE_9MB;
	case B43legacy_OFDM_RATE_18MB:
		return B43legacy_OFDM_RATE_12MB;
	case B43legacy_OFDM_RATE_24MB:
		return B43legacy_OFDM_RATE_18MB;
	case B43legacy_OFDM_RATE_36MB:
		return B43legacy_OFDM_RATE_24MB;
	case B43legacy_OFDM_RATE_48MB:
		return B43legacy_OFDM_RATE_36MB;
	case B43legacy_OFDM_RATE_54MB:
		return B43legacy_OFDM_RATE_48MB;
	}
	B43legacy_BUG_ON(1);
	return 0;
}

static int generate_txhdr_fw3(struct b43legacy_wldev *dev,
			       struct b43legacy_txhdr_fw3 *txhdr,
			       const unsigned char *fragment_data,
			       unsigned int fragment_len,
			       const struct ieee80211_tx_control *txctl,
			       u16 cookie)
{
	const struct ieee80211_hdr *wlhdr;
	int use_encryption = (!(txctl->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT));
	u16 fctl;
	u8 rate;
	u8 rate_fb;
	int rate_ofdm;
	int rate_fb_ofdm;
	unsigned int plcp_fragment_len;
	u32 mac_ctl = 0;
	u16 phy_ctl = 0;

	wlhdr = (const struct ieee80211_hdr *)fragment_data;
	fctl = le16_to_cpu(wlhdr->frame_control);

	memset(txhdr, 0, sizeof(*txhdr));

	rate = txctl->tx_rate;
	rate_ofdm = b43legacy_is_ofdm_rate(rate);
	rate_fb = (txctl->alt_retry_rate == -1) ? rate : txctl->alt_retry_rate;
	rate_fb_ofdm = b43legacy_is_ofdm_rate(rate_fb);

	txhdr->mac_frame_ctl = wlhdr->frame_control;
	memcpy(txhdr->tx_receiver, wlhdr->addr1, 6);

	/* Calculate duration for fallback rate */
	if ((rate_fb == rate) ||
	    (wlhdr->duration_id & cpu_to_le16(0x8000)) ||
	    (wlhdr->duration_id == cpu_to_le16(0))) {
		/* If the fallback rate equals the normal rate or the
		 * dur_id field contains an AID, CFP magic or 0,
		 * use the original dur_id field. */
		txhdr->dur_fb = wlhdr->duration_id;
	} else {
		int fbrate_base100kbps = B43legacy_RATE_TO_100KBPS(rate_fb);
		txhdr->dur_fb = ieee80211_generic_frame_duration(dev->wl->hw,
							 dev->wl->if_id,
							 fragment_len,
							 fbrate_base100kbps);
	}

	plcp_fragment_len = fragment_len + FCS_LEN;
	if (use_encryption) {
		u8 key_idx = (u16)(txctl->key_idx);
		struct b43legacy_key *key;
		int wlhdr_len;
		size_t iv_len;

		B43legacy_WARN_ON(key_idx >= dev->max_nr_keys);
		key = &(dev->key[key_idx]);

		if (key->enabled) {
			/* Hardware appends ICV. */
			plcp_fragment_len += txctl->icv_len;

			key_idx = b43legacy_kidx_to_fw(dev, key_idx);
			mac_ctl |= (key_idx << B43legacy_TX4_MAC_KEYIDX_SHIFT) &
				   B43legacy_TX4_MAC_KEYIDX;
			mac_ctl |= (key->algorithm <<
				   B43legacy_TX4_MAC_KEYALG_SHIFT) &
				   B43legacy_TX4_MAC_KEYALG;
			wlhdr_len = ieee80211_get_hdrlen(fctl);
			iv_len = min((size_t)txctl->iv_len,
				     ARRAY_SIZE(txhdr->iv));
			memcpy(txhdr->iv, ((u8 *)wlhdr) + wlhdr_len, iv_len);
		} else {
			/* This key is invalid. This might only happen
			 * in a short timeframe after machine resume before
			 * we were able to reconfigure keys.
			 * Drop this packet completely. Do not transmit it
			 * unencrypted to avoid leaking information. */
			return -ENOKEY;
		}
	}
	b43legacy_generate_plcp_hdr((struct b43legacy_plcp_hdr4 *)
				    (&txhdr->plcp), plcp_fragment_len,
				    rate);
	b43legacy_generate_plcp_hdr((struct b43legacy_plcp_hdr4 *)
				    (&txhdr->plcp_fb), plcp_fragment_len,
				    rate_fb);

	/* PHY TX Control word */
	if (rate_ofdm)
		phy_ctl |= B43legacy_TX4_PHY_OFDM;
	if (dev->short_preamble)
		phy_ctl |= B43legacy_TX4_PHY_SHORTPRMBL;
	switch (txctl->antenna_sel_tx) {
	case 0:
		phy_ctl |= B43legacy_TX4_PHY_ANTLAST;
		break;
	case 1:
		phy_ctl |= B43legacy_TX4_PHY_ANT0;
		break;
	case 2:
		phy_ctl |= B43legacy_TX4_PHY_ANT1;
		break;
	default:
		B43legacy_BUG_ON(1);
	}

	/* MAC control */
	if (!(txctl->flags & IEEE80211_TXCTL_NO_ACK))
		mac_ctl |= B43legacy_TX4_MAC_ACK;
	if (!(((fctl & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL) &&
	      ((fctl & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)))
		mac_ctl |= B43legacy_TX4_MAC_HWSEQ;
	if (txctl->flags & IEEE80211_TXCTL_FIRST_FRAGMENT)
		mac_ctl |= B43legacy_TX4_MAC_STMSDU;
	if (rate_fb_ofdm)
		mac_ctl |= B43legacy_TX4_MAC_FALLBACKOFDM;

	/* Generate the RTS or CTS-to-self frame */
	if ((txctl->flags & IEEE80211_TXCTL_USE_RTS_CTS) ||
	    (txctl->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)) {
		unsigned int len;
		struct ieee80211_hdr *hdr;
		int rts_rate;
		int rts_rate_fb;
		int rts_rate_ofdm;
		int rts_rate_fb_ofdm;

		rts_rate = txctl->rts_cts_rate;
		rts_rate_ofdm = b43legacy_is_ofdm_rate(rts_rate);
		rts_rate_fb = b43legacy_calc_fallback_rate(rts_rate);
		rts_rate_fb_ofdm = b43legacy_is_ofdm_rate(rts_rate_fb);
		if (rts_rate_fb_ofdm)
			mac_ctl |= B43legacy_TX4_MAC_CTSFALLBACKOFDM;

		if (txctl->flags & IEEE80211_TXCTL_USE_CTS_PROTECT) {
			ieee80211_ctstoself_get(dev->wl->hw,
						dev->wl->if_id,
						fragment_data,
						fragment_len, txctl,
						(struct ieee80211_cts *)
						(txhdr->rts_frame));
			mac_ctl |= B43legacy_TX4_MAC_SENDCTS;
			len = sizeof(struct ieee80211_cts);