linux/drivers/net/wireless/b43legacy/pio.c
Johannes Berg e6a9854b05 mac80211/drivers: rewrite the rate control API
So after the previous changes we were still unhappy with how
convoluted the API is and decided to make things simpler for
everybody. This completely changes the rate control API, now
taking into account 802.11n with MCS rates and more control,
most drivers don't support that though.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-10-31 19:00:23 -04:00

707 lines
18 KiB
C

/*
Broadcom B43legacy wireless driver
PIO Transmission
Copyright (c) 2005 Michael Buesch <mb@bu3sch.de>
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 "b43legacy.h"
#include "pio.h"
#include "main.h"
#include "xmit.h"
#include <linux/delay.h>
static void tx_start(struct b43legacy_pioqueue *queue)
{
b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
B43legacy_PIO_TXCTL_INIT);
}
static void tx_octet(struct b43legacy_pioqueue *queue,
u8 octet)
{
if (queue->need_workarounds) {
b43legacy_pio_write(queue, B43legacy_PIO_TXDATA, octet);
b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
B43legacy_PIO_TXCTL_WRITELO);
} else {
b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
B43legacy_PIO_TXCTL_WRITELO);
b43legacy_pio_write(queue, B43legacy_PIO_TXDATA, octet);
}
}
static u16 tx_get_next_word(const u8 *txhdr,
const u8 *packet,
size_t txhdr_size,
unsigned int *pos)
{
const u8 *source;
unsigned int i = *pos;
u16 ret;
if (i < txhdr_size)
source = txhdr;
else {
source = packet;
i -= txhdr_size;
}
ret = le16_to_cpu(*((__le16 *)(source + i)));
*pos += 2;
return ret;
}
static void tx_data(struct b43legacy_pioqueue *queue,
u8 *txhdr,
const u8 *packet,
unsigned int octets)
{
u16 data;
unsigned int i = 0;
if (queue->need_workarounds) {
data = tx_get_next_word(txhdr, packet,
sizeof(struct b43legacy_txhdr_fw3), &i);
b43legacy_pio_write(queue, B43legacy_PIO_TXDATA, data);
}
b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
B43legacy_PIO_TXCTL_WRITELO |
B43legacy_PIO_TXCTL_WRITEHI);
while (i < octets - 1) {
data = tx_get_next_word(txhdr, packet,
sizeof(struct b43legacy_txhdr_fw3), &i);
b43legacy_pio_write(queue, B43legacy_PIO_TXDATA, data);
}
if (octets % 2)
tx_octet(queue, packet[octets -
sizeof(struct b43legacy_txhdr_fw3) - 1]);
}
static void tx_complete(struct b43legacy_pioqueue *queue,
struct sk_buff *skb)
{
if (queue->need_workarounds) {
b43legacy_pio_write(queue, B43legacy_PIO_TXDATA,
skb->data[skb->len - 1]);
b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
B43legacy_PIO_TXCTL_WRITELO |
B43legacy_PIO_TXCTL_COMPLETE);
} else
b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
B43legacy_PIO_TXCTL_COMPLETE);
}
static u16 generate_cookie(struct b43legacy_pioqueue *queue,
struct b43legacy_pio_txpacket *packet)
{
u16 cookie = 0x0000;
int packetindex;
/* We use the upper 4 bits for the PIO
* controller ID and the lower 12 bits
* for the packet index (in the cache).
*/
switch (queue->mmio_base) {
case B43legacy_MMIO_PIO1_BASE:
break;
case B43legacy_MMIO_PIO2_BASE:
cookie = 0x1000;
break;
case B43legacy_MMIO_PIO3_BASE:
cookie = 0x2000;
break;
case B43legacy_MMIO_PIO4_BASE:
cookie = 0x3000;
break;
default:
B43legacy_WARN_ON(1);
}
packetindex = pio_txpacket_getindex(packet);
B43legacy_WARN_ON(!(((u16)packetindex & 0xF000) == 0x0000));
cookie |= (u16)packetindex;
return cookie;
}
static
struct b43legacy_pioqueue *parse_cookie(struct b43legacy_wldev *dev,
u16 cookie,
struct b43legacy_pio_txpacket **packet)
{
struct b43legacy_pio *pio = &dev->pio;
struct b43legacy_pioqueue *queue = NULL;
int packetindex;
switch (cookie & 0xF000) {
case 0x0000:
queue = pio->queue0;
break;
case 0x1000:
queue = pio->queue1;
break;
case 0x2000:
queue = pio->queue2;
break;
case 0x3000:
queue = pio->queue3;
break;
default:
B43legacy_WARN_ON(1);
}
packetindex = (cookie & 0x0FFF);
B43legacy_WARN_ON(!(packetindex >= 0 && packetindex
< B43legacy_PIO_MAXTXPACKETS));
*packet = &(queue->tx_packets_cache[packetindex]);
return queue;
}
union txhdr_union {
struct b43legacy_txhdr_fw3 txhdr_fw3;
};
static int pio_tx_write_fragment(struct b43legacy_pioqueue *queue,
struct sk_buff *skb,
struct b43legacy_pio_txpacket *packet,
size_t txhdr_size)
{
union txhdr_union txhdr_data;
u8 *txhdr = NULL;
unsigned int octets;
int err;
txhdr = (u8 *)(&txhdr_data.txhdr_fw3);
B43legacy_WARN_ON(skb_shinfo(skb)->nr_frags != 0);
err = b43legacy_generate_txhdr(queue->dev,
txhdr, skb->data, skb->len,
IEEE80211_SKB_CB(skb),
generate_cookie(queue, packet));
if (err)
return err;
tx_start(queue);
octets = skb->len + txhdr_size;
if (queue->need_workarounds)
octets--;
tx_data(queue, txhdr, (u8 *)skb->data, octets);
tx_complete(queue, skb);
return 0;
}
static void free_txpacket(struct b43legacy_pio_txpacket *packet,
int irq_context)
{
struct b43legacy_pioqueue *queue = packet->queue;
if (packet->skb) {
if (irq_context)
dev_kfree_skb_irq(packet->skb);
else
dev_kfree_skb(packet->skb);
}
list_move(&packet->list, &queue->txfree);
queue->nr_txfree++;
}
static int pio_tx_packet(struct b43legacy_pio_txpacket *packet)
{
struct b43legacy_pioqueue *queue = packet->queue;
struct sk_buff *skb = packet->skb;
u16 octets;
int err;
octets = (u16)skb->len + sizeof(struct b43legacy_txhdr_fw3);
if (queue->tx_devq_size < octets) {
b43legacywarn(queue->dev->wl, "PIO queue too small. "
"Dropping packet.\n");
/* Drop it silently (return success) */
free_txpacket(packet, 1);
return 0;
}
B43legacy_WARN_ON(queue->tx_devq_packets >
B43legacy_PIO_MAXTXDEVQPACKETS);
B43legacy_WARN_ON(queue->tx_devq_used > queue->tx_devq_size);
/* Check if there is sufficient free space on the device
* TX queue. If not, return and let the TX tasklet
* retry later.
*/
if (queue->tx_devq_packets == B43legacy_PIO_MAXTXDEVQPACKETS)
return -EBUSY;
if (queue->tx_devq_used + octets > queue->tx_devq_size)
return -EBUSY;
/* Now poke the device. */
err = pio_tx_write_fragment(queue, skb, packet,
sizeof(struct b43legacy_txhdr_fw3));
if (unlikely(err == -ENOKEY)) {
/* Drop this packet, as we don't have the encryption key
* anymore and must not transmit it unencrypted. */
free_txpacket(packet, 1);
return 0;
}
/* Account for the packet size.
* (We must not overflow the device TX queue)
*/
queue->tx_devq_packets++;
queue->tx_devq_used += octets;
/* Transmission started, everything ok, move the
* packet to the txrunning list.
*/
list_move_tail(&packet->list, &queue->txrunning);
return 0;
}
static void tx_tasklet(unsigned long d)
{
struct b43legacy_pioqueue *queue = (struct b43legacy_pioqueue *)d;
struct b43legacy_wldev *dev = queue->dev;
unsigned long flags;
struct b43legacy_pio_txpacket *packet, *tmp_packet;
int err;
u16 txctl;
spin_lock_irqsave(&dev->wl->irq_lock, flags);
if (queue->tx_frozen)
goto out_unlock;
txctl = b43legacy_pio_read(queue, B43legacy_PIO_TXCTL);
if (txctl & B43legacy_PIO_TXCTL_SUSPEND)
goto out_unlock;
list_for_each_entry_safe(packet, tmp_packet, &queue->txqueue, list) {
/* Try to transmit the packet. This can fail, if
* the device queue is full. In case of failure, the
* packet is left in the txqueue.
* If transmission succeed, the packet is moved to txrunning.
* If it is impossible to transmit the packet, it
* is dropped.
*/
err = pio_tx_packet(packet);
if (err)
break;
}
out_unlock:
spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
}
static void setup_txqueues(struct b43legacy_pioqueue *queue)
{
struct b43legacy_pio_txpacket *packet;
int i;
queue->nr_txfree = B43legacy_PIO_MAXTXPACKETS;
for (i = 0; i < B43legacy_PIO_MAXTXPACKETS; i++) {
packet = &(queue->tx_packets_cache[i]);
packet->queue = queue;
INIT_LIST_HEAD(&packet->list);
list_add(&packet->list, &queue->txfree);
}
}
static
struct b43legacy_pioqueue *b43legacy_setup_pioqueue(struct b43legacy_wldev *dev,
u16 pio_mmio_base)
{
struct b43legacy_pioqueue *queue;
u32 value;
u16 qsize;
queue = kzalloc(sizeof(*queue), GFP_KERNEL);
if (!queue)
goto out;
queue->dev = dev;
queue->mmio_base = pio_mmio_base;
queue->need_workarounds = (dev->dev->id.revision < 3);
INIT_LIST_HEAD(&queue->txfree);
INIT_LIST_HEAD(&queue->txqueue);
INIT_LIST_HEAD(&queue->txrunning);
tasklet_init(&queue->txtask, tx_tasklet,
(unsigned long)queue);
value = b43legacy_read32(dev, B43legacy_MMIO_MACCTL);
value &= ~B43legacy_MACCTL_BE;
b43legacy_write32(dev, B43legacy_MMIO_MACCTL, value);
qsize = b43legacy_read16(dev, queue->mmio_base
+ B43legacy_PIO_TXQBUFSIZE);
if (qsize == 0) {
b43legacyerr(dev->wl, "This card does not support PIO "
"operation mode. Please use DMA mode "
"(module parameter pio=0).\n");
goto err_freequeue;
}
if (qsize <= B43legacy_PIO_TXQADJUST) {
b43legacyerr(dev->wl, "PIO tx device-queue too small (%u)\n",
qsize);
goto err_freequeue;
}
qsize -= B43legacy_PIO_TXQADJUST;
queue->tx_devq_size = qsize;
setup_txqueues(queue);
out:
return queue;
err_freequeue:
kfree(queue);
queue = NULL;
goto out;
}
static void cancel_transfers(struct b43legacy_pioqueue *queue)
{
struct b43legacy_pio_txpacket *packet, *tmp_packet;
tasklet_disable(&queue->txtask);
list_for_each_entry_safe(packet, tmp_packet, &queue->txrunning, list)
free_txpacket(packet, 0);
list_for_each_entry_safe(packet, tmp_packet, &queue->txqueue, list)
free_txpacket(packet, 0);
}
static void b43legacy_destroy_pioqueue(struct b43legacy_pioqueue *queue)
{
if (!queue)
return;
cancel_transfers(queue);
kfree(queue);
}
void b43legacy_pio_free(struct b43legacy_wldev *dev)
{
struct b43legacy_pio *pio;
if (!b43legacy_using_pio(dev))
return;
pio = &dev->pio;
b43legacy_destroy_pioqueue(pio->queue3);
pio->queue3 = NULL;
b43legacy_destroy_pioqueue(pio->queue2);
pio->queue2 = NULL;
b43legacy_destroy_pioqueue(pio->queue1);
pio->queue1 = NULL;
b43legacy_destroy_pioqueue(pio->queue0);
pio->queue0 = NULL;
}
int b43legacy_pio_init(struct b43legacy_wldev *dev)
{
struct b43legacy_pio *pio = &dev->pio;
struct b43legacy_pioqueue *queue;
int err = -ENOMEM;
queue = b43legacy_setup_pioqueue(dev, B43legacy_MMIO_PIO1_BASE);
if (!queue)
goto out;
pio->queue0 = queue;
queue = b43legacy_setup_pioqueue(dev, B43legacy_MMIO_PIO2_BASE);
if (!queue)
goto err_destroy0;
pio->queue1 = queue;
queue = b43legacy_setup_pioqueue(dev, B43legacy_MMIO_PIO3_BASE);
if (!queue)
goto err_destroy1;
pio->queue2 = queue;
queue = b43legacy_setup_pioqueue(dev, B43legacy_MMIO_PIO4_BASE);
if (!queue)
goto err_destroy2;
pio->queue3 = queue;
if (dev->dev->id.revision < 3)
dev->irq_savedstate |= B43legacy_IRQ_PIO_WORKAROUND;
b43legacydbg(dev->wl, "PIO initialized\n");
err = 0;
out:
return err;
err_destroy2:
b43legacy_destroy_pioqueue(pio->queue2);
pio->queue2 = NULL;
err_destroy1:
b43legacy_destroy_pioqueue(pio->queue1);
pio->queue1 = NULL;
err_destroy0:
b43legacy_destroy_pioqueue(pio->queue0);
pio->queue0 = NULL;
goto out;
}
int b43legacy_pio_tx(struct b43legacy_wldev *dev,
struct sk_buff *skb)
{
struct b43legacy_pioqueue *queue = dev->pio.queue1;
struct b43legacy_pio_txpacket *packet;
B43legacy_WARN_ON(queue->tx_suspended);
B43legacy_WARN_ON(list_empty(&queue->txfree));
packet = list_entry(queue->txfree.next, struct b43legacy_pio_txpacket,
list);
packet->skb = skb;
list_move_tail(&packet->list, &queue->txqueue);
queue->nr_txfree--;
queue->nr_tx_packets++;
B43legacy_WARN_ON(queue->nr_txfree >= B43legacy_PIO_MAXTXPACKETS);
tasklet_schedule(&queue->txtask);
return 0;
}
void b43legacy_pio_handle_txstatus(struct b43legacy_wldev *dev,
const struct b43legacy_txstatus *status)
{
struct b43legacy_pioqueue *queue;
struct b43legacy_pio_txpacket *packet;
struct ieee80211_tx_info *info;
int retry_limit;
queue = parse_cookie(dev, status->cookie, &packet);
B43legacy_WARN_ON(!queue);
if (!packet->skb)
return;
queue->tx_devq_packets--;
queue->tx_devq_used -= (packet->skb->len +
sizeof(struct b43legacy_txhdr_fw3));
info = IEEE80211_SKB_CB(packet->skb);
/* preserve the confiured retry limit before clearing the status
* The xmit function has overwritten the rc's value with the actual
* retry limit done by the hardware */
retry_limit = info->status.rates[0].count;
ieee80211_tx_info_clear_status(info);
if (status->acked)
info->flags |= IEEE80211_TX_STAT_ACK;
if (status->rts_count > dev->wl->hw->conf.short_frame_max_tx_count) {
/*
* If the short retries (RTS, not data frame) have exceeded
* the limit, the hw will not have tried the selected rate,
* but will have used the fallback rate instead.
* Don't let the rate control count attempts for the selected
* rate in this case, otherwise the statistics will be off.
*/
info->status.rates[0].count = 0;
info->status.rates[1].count = status->frame_count;
} else {
if (status->frame_count > retry_limit) {
info->status.rates[0].count = retry_limit;
info->status.rates[1].count = status->frame_count -
retry_limit;
} else {
info->status.rates[0].count = status->frame_count;
info->status.rates[1].idx = -1;
}
}
ieee80211_tx_status_irqsafe(dev->wl->hw, packet->skb);
packet->skb = NULL;
free_txpacket(packet, 1);
/* If there are packets on the txqueue, poke the tasklet
* to transmit them.
*/
if (!list_empty(&queue->txqueue))
tasklet_schedule(&queue->txtask);
}
void b43legacy_pio_get_tx_stats(struct b43legacy_wldev *dev,
struct ieee80211_tx_queue_stats *stats)
{
struct b43legacy_pio *pio = &dev->pio;
struct b43legacy_pioqueue *queue;
queue = pio->queue1;
stats[0].len = B43legacy_PIO_MAXTXPACKETS - queue->nr_txfree;
stats[0].limit = B43legacy_PIO_MAXTXPACKETS;
stats[0].count = queue->nr_tx_packets;
}
static void pio_rx_error(struct b43legacy_pioqueue *queue,
int clear_buffers,
const char *error)
{
int i;
b43legacyerr(queue->dev->wl, "PIO RX error: %s\n", error);
b43legacy_pio_write(queue, B43legacy_PIO_RXCTL,
B43legacy_PIO_RXCTL_READY);
if (clear_buffers) {
B43legacy_WARN_ON(queue->mmio_base != B43legacy_MMIO_PIO1_BASE);
for (i = 0; i < 15; i++) {
/* Dummy read. */
b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
}
}
}
void b43legacy_pio_rx(struct b43legacy_pioqueue *queue)
{
__le16 preamble[21] = { 0 };
struct b43legacy_rxhdr_fw3 *rxhdr;
u16 tmp;
u16 len;
u16 macstat;
int i;
int preamble_readwords;
struct sk_buff *skb;
tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXCTL);
if (!(tmp & B43legacy_PIO_RXCTL_DATAAVAILABLE))
return;
b43legacy_pio_write(queue, B43legacy_PIO_RXCTL,
B43legacy_PIO_RXCTL_DATAAVAILABLE);
for (i = 0; i < 10; i++) {
tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXCTL);
if (tmp & B43legacy_PIO_RXCTL_READY)
goto data_ready;
udelay(10);
}
b43legacydbg(queue->dev->wl, "PIO RX timed out\n");
return;
data_ready:
len = b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
if (unlikely(len > 0x700)) {
pio_rx_error(queue, 0, "len > 0x700");
return;
}
if (unlikely(len == 0 && queue->mmio_base !=
B43legacy_MMIO_PIO4_BASE)) {
pio_rx_error(queue, 0, "len == 0");
return;
}
preamble[0] = cpu_to_le16(len);
if (queue->mmio_base == B43legacy_MMIO_PIO4_BASE)
preamble_readwords = 14 / sizeof(u16);
else
preamble_readwords = 18 / sizeof(u16);
for (i = 0; i < preamble_readwords; i++) {
tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
preamble[i + 1] = cpu_to_le16(tmp);
}
rxhdr = (struct b43legacy_rxhdr_fw3 *)preamble;
macstat = le16_to_cpu(rxhdr->mac_status);
if (macstat & B43legacy_RX_MAC_FCSERR) {
pio_rx_error(queue,
(queue->mmio_base == B43legacy_MMIO_PIO1_BASE),
"Frame FCS error");
return;
}
if (queue->mmio_base == B43legacy_MMIO_PIO4_BASE) {
/* We received an xmit status. */
struct b43legacy_hwtxstatus *hw;
hw = (struct b43legacy_hwtxstatus *)(preamble + 1);
b43legacy_handle_hwtxstatus(queue->dev, hw);
return;
}
skb = dev_alloc_skb(len);
if (unlikely(!skb)) {
pio_rx_error(queue, 1, "OOM");
return;
}
skb_put(skb, len);
for (i = 0; i < len - 1; i += 2) {
tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
*((__le16 *)(skb->data + i)) = cpu_to_le16(tmp);
}
if (len % 2) {
tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
skb->data[len - 1] = (tmp & 0x00FF);
}
b43legacy_rx(queue->dev, skb, rxhdr);
}
void b43legacy_pio_tx_suspend(struct b43legacy_pioqueue *queue)
{
b43legacy_power_saving_ctl_bits(queue->dev, -1, 1);
b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
b43legacy_pio_read(queue, B43legacy_PIO_TXCTL)
| B43legacy_PIO_TXCTL_SUSPEND);
}
void b43legacy_pio_tx_resume(struct b43legacy_pioqueue *queue)
{
b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
b43legacy_pio_read(queue, B43legacy_PIO_TXCTL)
& ~B43legacy_PIO_TXCTL_SUSPEND);
b43legacy_power_saving_ctl_bits(queue->dev, -1, -1);
tasklet_schedule(&queue->txtask);
}
void b43legacy_pio_freeze_txqueues(struct b43legacy_wldev *dev)
{
struct b43legacy_pio *pio;
B43legacy_WARN_ON(!b43legacy_using_pio(dev));
pio = &dev->pio;
pio->queue0->tx_frozen = 1;
pio->queue1->tx_frozen = 1;
pio->queue2->tx_frozen = 1;
pio->queue3->tx_frozen = 1;
}
void b43legacy_pio_thaw_txqueues(struct b43legacy_wldev *dev)
{
struct b43legacy_pio *pio;
B43legacy_WARN_ON(!b43legacy_using_pio(dev));
pio = &dev->pio;
pio->queue0->tx_frozen = 0;
pio->queue1->tx_frozen = 0;
pio->queue2->tx_frozen = 0;
pio->queue3->tx_frozen = 0;
if (!list_empty(&pio->queue0->txqueue))
tasklet_schedule(&pio->queue0->txtask);
if (!list_empty(&pio->queue1->txqueue))
tasklet_schedule(&pio->queue1->txtask);
if (!list_empty(&pio->queue2->txqueue))
tasklet_schedule(&pio->queue2->txtask);
if (!list_empty(&pio->queue3->txqueue))
tasklet_schedule(&pio->queue3->txtask);
}