linux/drivers/net/wireless/bcm43xx/bcm43xx_pio.c

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/*
Broadcom BCM43xx wireless driver
PIO Transmission
Copyright (c) 2005 Michael Buesch <mbuesch@freenet.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 "bcm43xx.h"
#include "bcm43xx_pio.h"
#include "bcm43xx_main.h"
#include "bcm43xx_xmit.h"
#include "bcm43xx_power.h"
#include <linux/delay.h>
static void tx_start(struct bcm43xx_pioqueue *queue)
{
bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
BCM43xx_PIO_TXCTL_INIT);
}
static void tx_octet(struct bcm43xx_pioqueue *queue,
u8 octet)
{
if (queue->need_workarounds) {
bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA,
octet);
bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
BCM43xx_PIO_TXCTL_WRITELO);
} else {
bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
BCM43xx_PIO_TXCTL_WRITELO);
bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA,
octet);
}
}
static u16 tx_get_next_word(struct bcm43xx_txhdr *txhdr,
const u8 *packet,
unsigned int *pos)
{
const u8 *source;
unsigned int i = *pos;
u16 ret;
if (i < sizeof(*txhdr)) {
source = (const u8 *)txhdr;
} else {
source = packet;
i -= sizeof(*txhdr);
}
ret = le16_to_cpu( *((u16 *)(source + i)) );
*pos += 2;
return ret;
}
static void tx_data(struct bcm43xx_pioqueue *queue,
struct bcm43xx_txhdr *txhdr,
const u8 *packet,
unsigned int octets)
{
u16 data;
unsigned int i = 0;
if (queue->need_workarounds) {
data = tx_get_next_word(txhdr, packet, &i);
bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA, data);
}
bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
BCM43xx_PIO_TXCTL_WRITELO |
BCM43xx_PIO_TXCTL_WRITEHI);
while (i < octets - 1) {
data = tx_get_next_word(txhdr, packet, &i);
bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA, data);
}
if (octets % 2)
tx_octet(queue, packet[octets - sizeof(*txhdr) - 1]);
}
static void tx_complete(struct bcm43xx_pioqueue *queue,
struct sk_buff *skb)
{
if (queue->need_workarounds) {
bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA,
skb->data[skb->len - 1]);
bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
BCM43xx_PIO_TXCTL_WRITELO |
BCM43xx_PIO_TXCTL_COMPLETE);
} else {
bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
BCM43xx_PIO_TXCTL_COMPLETE);
}
}
static u16 generate_cookie(struct bcm43xx_pioqueue *queue,
struct bcm43xx_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 BCM43xx_MMIO_PIO1_BASE:
break;
case BCM43xx_MMIO_PIO2_BASE:
cookie = 0x1000;
break;
case BCM43xx_MMIO_PIO3_BASE:
cookie = 0x2000;
break;
case BCM43xx_MMIO_PIO4_BASE:
cookie = 0x3000;
break;
default:
assert(0);
}
packetindex = pio_txpacket_getindex(packet);
assert(((u16)packetindex & 0xF000) == 0x0000);
cookie |= (u16)packetindex;
return cookie;
}
static
struct bcm43xx_pioqueue * parse_cookie(struct bcm43xx_private *bcm,
u16 cookie,
struct bcm43xx_pio_txpacket **packet)
{
struct bcm43xx_pio *pio = bcm43xx_current_pio(bcm);
struct bcm43xx_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:
assert(0);
}
packetindex = (cookie & 0x0FFF);
assert(packetindex >= 0 && packetindex < BCM43xx_PIO_MAXTXPACKETS);
*packet = &(queue->tx_packets_cache[packetindex]);
return queue;
}
static void pio_tx_write_fragment(struct bcm43xx_pioqueue *queue,
struct sk_buff *skb,
struct bcm43xx_pio_txpacket *packet)
{
struct bcm43xx_txhdr txhdr;
unsigned int octets;
assert(skb_shinfo(skb)->nr_frags == 0);
bcm43xx_generate_txhdr(queue->bcm,
&txhdr, skb->data, skb->len,
(packet->xmitted_frags == 0),
generate_cookie(queue, packet));
tx_start(queue);
octets = skb->len + sizeof(txhdr);
if (queue->need_workarounds)
octets--;
tx_data(queue, &txhdr, (u8 *)skb->data, octets);
tx_complete(queue, skb);
}
static void free_txpacket(struct bcm43xx_pio_txpacket *packet,
int irq_context)
{
struct bcm43xx_pioqueue *queue = packet->queue;
ieee80211_txb_free(packet->txb);
list_move(&packet->list, &queue->txfree);
queue->nr_txfree++;
assert(queue->tx_devq_used >= packet->xmitted_octets);
assert(queue->tx_devq_packets >= packet->xmitted_frags);
queue->tx_devq_used -= packet->xmitted_octets;
queue->tx_devq_packets -= packet->xmitted_frags;
}
static int pio_tx_packet(struct bcm43xx_pio_txpacket *packet)
{
struct bcm43xx_pioqueue *queue = packet->queue;
struct ieee80211_txb *txb = packet->txb;
struct sk_buff *skb;
u16 octets;
int i;
for (i = packet->xmitted_frags; i < txb->nr_frags; i++) {
skb = txb->fragments[i];
octets = (u16)skb->len + sizeof(struct bcm43xx_txhdr);
assert(queue->tx_devq_size >= octets);
assert(queue->tx_devq_packets <= BCM43xx_PIO_MAXTXDEVQPACKETS);
assert(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 == BCM43xx_PIO_MAXTXDEVQPACKETS)
return -EBUSY;
if (queue->tx_devq_used + octets > queue->tx_devq_size)
return -EBUSY;
/* Now poke the device. */
pio_tx_write_fragment(queue, skb, packet);
/* Account for the packet size.
* (We must not overflow the device TX queue)
*/
queue->tx_devq_packets++;
queue->tx_devq_used += octets;
assert(packet->xmitted_frags < packet->txb->nr_frags);
packet->xmitted_frags++;
packet->xmitted_octets += octets;
}
list_move_tail(&packet->list, &queue->txrunning);
return 0;
}
static void tx_tasklet(unsigned long d)
{
struct bcm43xx_pioqueue *queue = (struct bcm43xx_pioqueue *)d;
struct bcm43xx_private *bcm = queue->bcm;
unsigned long flags;
struct bcm43xx_pio_txpacket *packet, *tmp_packet;
int err;
u16 txctl;
spin_lock_irqsave(&bcm->irq_lock, flags);
if (queue->tx_frozen)
goto out_unlock;
txctl = bcm43xx_pio_read(queue, BCM43xx_PIO_TXCTL);
if (txctl & BCM43xx_PIO_TXCTL_SUSPEND)
goto out_unlock;
list_for_each_entry_safe(packet, tmp_packet, &queue->txqueue, list) {
assert(packet->xmitted_frags < packet->txb->nr_frags);
if (packet->xmitted_frags == 0) {
int i;
struct sk_buff *skb;
/* Check if the device queue is big
* enough for every fragment. If not, drop the
* whole packet.
*/
for (i = 0; i < packet->txb->nr_frags; i++) {
skb = packet->txb->fragments[i];
if (unlikely(skb->len > queue->tx_devq_size)) {
dprintkl(KERN_ERR PFX "PIO TX device queue too small. "
"Dropping packet.\n");
free_txpacket(packet, 1);
goto next_packet;
}
}
}
/* Try to transmit the packet.
* This may not completely succeed.
*/
err = pio_tx_packet(packet);
if (err)
break;
next_packet:
continue;
}
out_unlock:
spin_unlock_irqrestore(&bcm->irq_lock, flags);
}
static void setup_txqueues(struct bcm43xx_pioqueue *queue)
{
struct bcm43xx_pio_txpacket *packet;
int i;
queue->nr_txfree = BCM43xx_PIO_MAXTXPACKETS;
for (i = 0; i < BCM43xx_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 bcm43xx_pioqueue * bcm43xx_setup_pioqueue(struct bcm43xx_private *bcm,
u16 pio_mmio_base)
{
struct bcm43xx_pioqueue *queue;
u32 value;
u16 qsize;
queue = kzalloc(sizeof(*queue), GFP_KERNEL);
if (!queue)
goto out;
queue->bcm = bcm;
queue->mmio_base = pio_mmio_base;
queue->need_workarounds = (bcm->current_core->rev < 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 = bcm43xx_read32(bcm, BCM43xx_MMIO_STATUS_BITFIELD);
value &= ~BCM43xx_SBF_XFER_REG_BYTESWAP;
bcm43xx_write32(bcm, BCM43xx_MMIO_STATUS_BITFIELD, value);
qsize = bcm43xx_read16(bcm, queue->mmio_base + BCM43xx_PIO_TXQBUFSIZE);
if (qsize == 0) {
printk(KERN_ERR PFX "ERROR: This card does not support PIO "
"operation mode. Please use DMA mode "
"(module parameter pio=0).\n");
goto err_freequeue;
}
if (qsize <= BCM43xx_PIO_TXQADJUST) {
printk(KERN_ERR PFX "PIO tx device-queue too small (%u)\n",
qsize);
goto err_freequeue;
}
qsize -= BCM43xx_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 bcm43xx_pioqueue *queue)
{
struct bcm43xx_pio_txpacket *packet, *tmp_packet;
netif_tx_disable(queue->bcm->net_dev);
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 bcm43xx_destroy_pioqueue(struct bcm43xx_pioqueue *queue)
{
if (!queue)
return;
cancel_transfers(queue);
kfree(queue);
}
void bcm43xx_pio_free(struct bcm43xx_private *bcm)
{
struct bcm43xx_pio *pio;
if (!bcm43xx_using_pio(bcm))
return;
pio = bcm43xx_current_pio(bcm);
bcm43xx_destroy_pioqueue(pio->queue3);
pio->queue3 = NULL;
bcm43xx_destroy_pioqueue(pio->queue2);
pio->queue2 = NULL;
bcm43xx_destroy_pioqueue(pio->queue1);
pio->queue1 = NULL;
bcm43xx_destroy_pioqueue(pio->queue0);
pio->queue0 = NULL;
}
int bcm43xx_pio_init(struct bcm43xx_private *bcm)
{
struct bcm43xx_pio *pio = bcm43xx_current_pio(bcm);
struct bcm43xx_pioqueue *queue;
int err = -ENOMEM;
queue = bcm43xx_setup_pioqueue(bcm, BCM43xx_MMIO_PIO1_BASE);
if (!queue)
goto out;
pio->queue0 = queue;
queue = bcm43xx_setup_pioqueue(bcm, BCM43xx_MMIO_PIO2_BASE);
if (!queue)
goto err_destroy0;
pio->queue1 = queue;
queue = bcm43xx_setup_pioqueue(bcm, BCM43xx_MMIO_PIO3_BASE);
if (!queue)
goto err_destroy1;
pio->queue2 = queue;
queue = bcm43xx_setup_pioqueue(bcm, BCM43xx_MMIO_PIO4_BASE);
if (!queue)
goto err_destroy2;
pio->queue3 = queue;
if (bcm->current_core->rev < 3)
bcm->irq_savedstate |= BCM43xx_IRQ_PIO_WORKAROUND;
dprintk(KERN_INFO PFX "PIO initialized\n");
err = 0;
out:
return err;
err_destroy2:
bcm43xx_destroy_pioqueue(pio->queue2);
pio->queue2 = NULL;
err_destroy1:
bcm43xx_destroy_pioqueue(pio->queue1);
pio->queue1 = NULL;
err_destroy0:
bcm43xx_destroy_pioqueue(pio->queue0);
pio->queue0 = NULL;
goto out;
}
int bcm43xx_pio_tx(struct bcm43xx_private *bcm,
struct ieee80211_txb *txb)
{
struct bcm43xx_pioqueue *queue = bcm43xx_current_pio(bcm)->queue1;
struct bcm43xx_pio_txpacket *packet;
assert(!queue->tx_suspended);
assert(!list_empty(&queue->txfree));
packet = list_entry(queue->txfree.next, struct bcm43xx_pio_txpacket, list);
packet->txb = txb;
packet->xmitted_frags = 0;
packet->xmitted_octets = 0;
list_move_tail(&packet->list, &queue->txqueue);
queue->nr_txfree--;
assert(queue->nr_txfree < BCM43xx_PIO_MAXTXPACKETS);
/* Suspend TX, if we are out of packets in the "free" queue. */
if (list_empty(&queue->txfree)) {
netif_stop_queue(queue->bcm->net_dev);
queue->tx_suspended = 1;
}
tasklet_schedule(&queue->txtask);
return 0;
}
void bcm43xx_pio_handle_xmitstatus(struct bcm43xx_private *bcm,
struct bcm43xx_xmitstatus *status)
{
struct bcm43xx_pioqueue *queue;
struct bcm43xx_pio_txpacket *packet;
queue = parse_cookie(bcm, status->cookie, &packet);
assert(queue);
free_txpacket(packet, 1);
if (queue->tx_suspended) {
queue->tx_suspended = 0;
netif_wake_queue(queue->bcm->net_dev);
}
/* If there are packets on the txqueue, poke the tasklet
* to transmit them.
*/
if (!list_empty(&queue->txqueue))
tasklet_schedule(&queue->txtask);
}
static void pio_rx_error(struct bcm43xx_pioqueue *queue,
int clear_buffers,
const char *error)
{
int i;
printkl("PIO RX error: %s\n", error);
bcm43xx_pio_write(queue, BCM43xx_PIO_RXCTL,
BCM43xx_PIO_RXCTL_READY);
if (clear_buffers) {
assert(queue->mmio_base == BCM43xx_MMIO_PIO1_BASE);
for (i = 0; i < 15; i++) {
/* Dummy read. */
bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA);
}
}
}
void bcm43xx_pio_rx(struct bcm43xx_pioqueue *queue)
{
u16 preamble[21] = { 0 };
struct bcm43xx_rxhdr *rxhdr;
u16 tmp, len, rxflags2;
int i, preamble_readwords;
struct sk_buff *skb;
tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_RXCTL);
if (!(tmp & BCM43xx_PIO_RXCTL_DATAAVAILABLE))
return;
bcm43xx_pio_write(queue, BCM43xx_PIO_RXCTL,
BCM43xx_PIO_RXCTL_DATAAVAILABLE);
for (i = 0; i < 10; i++) {
tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_RXCTL);
if (tmp & BCM43xx_PIO_RXCTL_READY)
goto data_ready;
udelay(10);
}
dprintkl(KERN_ERR PFX "PIO RX timed out\n");
return;
data_ready:
len = bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA);
if (unlikely(len > 0x700)) {
pio_rx_error(queue, 0, "len > 0x700");
return;
}
if (unlikely(len == 0 && queue->mmio_base != BCM43xx_MMIO_PIO4_BASE)) {
pio_rx_error(queue, 0, "len == 0");
return;
}
preamble[0] = cpu_to_le16(len);
if (queue->mmio_base == BCM43xx_MMIO_PIO4_BASE)
preamble_readwords = 14 / sizeof(u16);
else
preamble_readwords = 18 / sizeof(u16);
for (i = 0; i < preamble_readwords; i++) {
tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA);
preamble[i + 1] = cpu_to_le16(tmp);
}
rxhdr = (struct bcm43xx_rxhdr *)preamble;
rxflags2 = le16_to_cpu(rxhdr->flags2);
if (unlikely(rxflags2 & BCM43xx_RXHDR_FLAGS2_INVALIDFRAME)) {
pio_rx_error(queue,
(queue->mmio_base == BCM43xx_MMIO_PIO1_BASE),
"invalid frame");
return;
}
if (queue->mmio_base == BCM43xx_MMIO_PIO4_BASE) {
/* We received an xmit status. */
struct bcm43xx_hwxmitstatus *hw;
struct bcm43xx_xmitstatus stat;
hw = (struct bcm43xx_hwxmitstatus *)(preamble + 1);
stat.cookie = le16_to_cpu(hw->cookie);
stat.flags = hw->flags;
stat.cnt1 = hw->cnt1;
stat.cnt2 = hw->cnt2;
stat.seq = le16_to_cpu(hw->seq);
stat.unknown = le16_to_cpu(hw->unknown);
bcm43xx_debugfs_log_txstat(queue->bcm, &stat);
bcm43xx_pio_handle_xmitstatus(queue->bcm, &stat);
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 = bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA);
*((u16 *)(skb->data + i)) = cpu_to_le16(tmp);
}
if (len % 2) {
tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA);
skb->data[len - 1] = (tmp & 0x00FF);
/* The specs say the following is required, but
* it is wrong and corrupts the PLCP. If we don't do
* this, the PLCP seems to be correct. So ifdef it out for now.
*/
#if 0
if (rxflags2 & BCM43xx_RXHDR_FLAGS2_TYPE2FRAME)
skb->data[2] = (tmp & 0xFF00) >> 8;
else
skb->data[0] = (tmp & 0xFF00) >> 8;
#endif
}
skb_trim(skb, len - IEEE80211_FCS_LEN);
bcm43xx_rx(queue->bcm, skb, rxhdr);
}
void bcm43xx_pio_tx_suspend(struct bcm43xx_pioqueue *queue)
{
bcm43xx_power_saving_ctl_bits(queue->bcm, -1, 1);
bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
bcm43xx_pio_read(queue, BCM43xx_PIO_TXCTL)
| BCM43xx_PIO_TXCTL_SUSPEND);
}
void bcm43xx_pio_tx_resume(struct bcm43xx_pioqueue *queue)
{
bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
bcm43xx_pio_read(queue, BCM43xx_PIO_TXCTL)
& ~BCM43xx_PIO_TXCTL_SUSPEND);
bcm43xx_power_saving_ctl_bits(queue->bcm, -1, -1);
if (!list_empty(&queue->txqueue))
tasklet_schedule(&queue->txtask);
}
void bcm43xx_pio_freeze_txqueues(struct bcm43xx_private *bcm)
{
struct bcm43xx_pio *pio;
assert(bcm43xx_using_pio(bcm));
pio = bcm43xx_current_pio(bcm);
pio->queue0->tx_frozen = 1;
pio->queue1->tx_frozen = 1;
pio->queue2->tx_frozen = 1;
pio->queue3->tx_frozen = 1;
}
void bcm43xx_pio_thaw_txqueues(struct bcm43xx_private *bcm)
{
struct bcm43xx_pio *pio;
assert(bcm43xx_using_pio(bcm));
pio = bcm43xx_current_pio(bcm);
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);
}