linux/drivers/isdn/mISDN/hwchannel.c
Tejun Heo 43829731dd workqueue: deprecate flush[_delayed]_work_sync()
flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
and convert all users to flush[_delayed]_work().

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant and the regular flushes guarantee that the work item is
not pending or running on any CPU on return, so there's no reason to
use the sync flushes at all and they're going away.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mattia Dongili <malattia@linux.it>
Cc: Kent Yoder <key@linux.vnet.ibm.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Bryan Wu <bryan.wu@canonical.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Avi Kivity <avi@redhat.com>
2012-08-20 14:51:24 -07:00

528 lines
12 KiB
C

/*
*
* Author Karsten Keil <kkeil@novell.com>
*
* Copyright 2008 by Karsten Keil <kkeil@novell.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
*/
#include <linux/gfp.h>
#include <linux/module.h>
#include <linux/mISDNhw.h>
static void
dchannel_bh(struct work_struct *ws)
{
struct dchannel *dch = container_of(ws, struct dchannel, workq);
struct sk_buff *skb;
int err;
if (test_and_clear_bit(FLG_RECVQUEUE, &dch->Flags)) {
while ((skb = skb_dequeue(&dch->rqueue))) {
if (likely(dch->dev.D.peer)) {
err = dch->dev.D.recv(dch->dev.D.peer, skb);
if (err)
dev_kfree_skb(skb);
} else
dev_kfree_skb(skb);
}
}
if (test_and_clear_bit(FLG_PHCHANGE, &dch->Flags)) {
if (dch->phfunc)
dch->phfunc(dch);
}
}
static void
bchannel_bh(struct work_struct *ws)
{
struct bchannel *bch = container_of(ws, struct bchannel, workq);
struct sk_buff *skb;
int err;
if (test_and_clear_bit(FLG_RECVQUEUE, &bch->Flags)) {
while ((skb = skb_dequeue(&bch->rqueue))) {
bch->rcount--;
if (likely(bch->ch.peer)) {
err = bch->ch.recv(bch->ch.peer, skb);
if (err)
dev_kfree_skb(skb);
} else
dev_kfree_skb(skb);
}
}
}
int
mISDN_initdchannel(struct dchannel *ch, int maxlen, void *phf)
{
test_and_set_bit(FLG_HDLC, &ch->Flags);
ch->maxlen = maxlen;
ch->hw = NULL;
ch->rx_skb = NULL;
ch->tx_skb = NULL;
ch->tx_idx = 0;
ch->phfunc = phf;
skb_queue_head_init(&ch->squeue);
skb_queue_head_init(&ch->rqueue);
INIT_LIST_HEAD(&ch->dev.bchannels);
INIT_WORK(&ch->workq, dchannel_bh);
return 0;
}
EXPORT_SYMBOL(mISDN_initdchannel);
int
mISDN_initbchannel(struct bchannel *ch, unsigned short maxlen,
unsigned short minlen)
{
ch->Flags = 0;
ch->minlen = minlen;
ch->next_minlen = minlen;
ch->init_minlen = minlen;
ch->maxlen = maxlen;
ch->next_maxlen = maxlen;
ch->init_maxlen = maxlen;
ch->hw = NULL;
ch->rx_skb = NULL;
ch->tx_skb = NULL;
ch->tx_idx = 0;
skb_queue_head_init(&ch->rqueue);
ch->rcount = 0;
ch->next_skb = NULL;
INIT_WORK(&ch->workq, bchannel_bh);
return 0;
}
EXPORT_SYMBOL(mISDN_initbchannel);
int
mISDN_freedchannel(struct dchannel *ch)
{
if (ch->tx_skb) {
dev_kfree_skb(ch->tx_skb);
ch->tx_skb = NULL;
}
if (ch->rx_skb) {
dev_kfree_skb(ch->rx_skb);
ch->rx_skb = NULL;
}
skb_queue_purge(&ch->squeue);
skb_queue_purge(&ch->rqueue);
flush_work(&ch->workq);
return 0;
}
EXPORT_SYMBOL(mISDN_freedchannel);
void
mISDN_clear_bchannel(struct bchannel *ch)
{
if (ch->tx_skb) {
dev_kfree_skb(ch->tx_skb);
ch->tx_skb = NULL;
}
ch->tx_idx = 0;
if (ch->rx_skb) {
dev_kfree_skb(ch->rx_skb);
ch->rx_skb = NULL;
}
if (ch->next_skb) {
dev_kfree_skb(ch->next_skb);
ch->next_skb = NULL;
}
test_and_clear_bit(FLG_TX_BUSY, &ch->Flags);
test_and_clear_bit(FLG_TX_NEXT, &ch->Flags);
test_and_clear_bit(FLG_ACTIVE, &ch->Flags);
test_and_clear_bit(FLG_FILLEMPTY, &ch->Flags);
test_and_clear_bit(FLG_TX_EMPTY, &ch->Flags);
test_and_clear_bit(FLG_RX_OFF, &ch->Flags);
ch->dropcnt = 0;
ch->minlen = ch->init_minlen;
ch->next_minlen = ch->init_minlen;
ch->maxlen = ch->init_maxlen;
ch->next_maxlen = ch->init_maxlen;
}
EXPORT_SYMBOL(mISDN_clear_bchannel);
int
mISDN_freebchannel(struct bchannel *ch)
{
mISDN_clear_bchannel(ch);
skb_queue_purge(&ch->rqueue);
ch->rcount = 0;
flush_work(&ch->workq);
return 0;
}
EXPORT_SYMBOL(mISDN_freebchannel);
int
mISDN_ctrl_bchannel(struct bchannel *bch, struct mISDN_ctrl_req *cq)
{
int ret = 0;
switch (cq->op) {
case MISDN_CTRL_GETOP:
cq->op = MISDN_CTRL_RX_BUFFER | MISDN_CTRL_FILL_EMPTY |
MISDN_CTRL_RX_OFF;
break;
case MISDN_CTRL_FILL_EMPTY:
if (cq->p1) {
memset(bch->fill, cq->p2 & 0xff, MISDN_BCH_FILL_SIZE);
test_and_set_bit(FLG_FILLEMPTY, &bch->Flags);
} else {
test_and_clear_bit(FLG_FILLEMPTY, &bch->Flags);
}
break;
case MISDN_CTRL_RX_OFF:
/* read back dropped byte count */
cq->p2 = bch->dropcnt;
if (cq->p1)
test_and_set_bit(FLG_RX_OFF, &bch->Flags);
else
test_and_clear_bit(FLG_RX_OFF, &bch->Flags);
bch->dropcnt = 0;
break;
case MISDN_CTRL_RX_BUFFER:
if (cq->p2 > MISDN_CTRL_RX_SIZE_IGNORE)
bch->next_maxlen = cq->p2;
if (cq->p1 > MISDN_CTRL_RX_SIZE_IGNORE)
bch->next_minlen = cq->p1;
/* we return the old values */
cq->p1 = bch->minlen;
cq->p2 = bch->maxlen;
break;
default:
pr_info("mISDN unhandled control %x operation\n", cq->op);
ret = -EINVAL;
break;
}
return ret;
}
EXPORT_SYMBOL(mISDN_ctrl_bchannel);
static inline u_int
get_sapi_tei(u_char *p)
{
u_int sapi, tei;
sapi = *p >> 2;
tei = p[1] >> 1;
return sapi | (tei << 8);
}
void
recv_Dchannel(struct dchannel *dch)
{
struct mISDNhead *hh;
if (dch->rx_skb->len < 2) { /* at least 2 for sapi / tei */
dev_kfree_skb(dch->rx_skb);
dch->rx_skb = NULL;
return;
}
hh = mISDN_HEAD_P(dch->rx_skb);
hh->prim = PH_DATA_IND;
hh->id = get_sapi_tei(dch->rx_skb->data);
skb_queue_tail(&dch->rqueue, dch->rx_skb);
dch->rx_skb = NULL;
schedule_event(dch, FLG_RECVQUEUE);
}
EXPORT_SYMBOL(recv_Dchannel);
void
recv_Echannel(struct dchannel *ech, struct dchannel *dch)
{
struct mISDNhead *hh;
if (ech->rx_skb->len < 2) { /* at least 2 for sapi / tei */
dev_kfree_skb(ech->rx_skb);
ech->rx_skb = NULL;
return;
}
hh = mISDN_HEAD_P(ech->rx_skb);
hh->prim = PH_DATA_E_IND;
hh->id = get_sapi_tei(ech->rx_skb->data);
skb_queue_tail(&dch->rqueue, ech->rx_skb);
ech->rx_skb = NULL;
schedule_event(dch, FLG_RECVQUEUE);
}
EXPORT_SYMBOL(recv_Echannel);
void
recv_Bchannel(struct bchannel *bch, unsigned int id, bool force)
{
struct mISDNhead *hh;
/* if allocation did fail upper functions still may call us */
if (unlikely(!bch->rx_skb))
return;
if (unlikely(!bch->rx_skb->len)) {
/* we have no data to send - this may happen after recovery
* from overflow or too small allocation.
* We need to free the buffer here */
dev_kfree_skb(bch->rx_skb);
bch->rx_skb = NULL;
} else {
if (test_bit(FLG_TRANSPARENT, &bch->Flags) &&
(bch->rx_skb->len < bch->minlen) && !force)
return;
hh = mISDN_HEAD_P(bch->rx_skb);
hh->prim = PH_DATA_IND;
hh->id = id;
if (bch->rcount >= 64) {
printk(KERN_WARNING
"B%d receive queue overflow - flushing!\n",
bch->nr);
skb_queue_purge(&bch->rqueue);
}
bch->rcount++;
skb_queue_tail(&bch->rqueue, bch->rx_skb);
bch->rx_skb = NULL;
schedule_event(bch, FLG_RECVQUEUE);
}
}
EXPORT_SYMBOL(recv_Bchannel);
void
recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb)
{
skb_queue_tail(&dch->rqueue, skb);
schedule_event(dch, FLG_RECVQUEUE);
}
EXPORT_SYMBOL(recv_Dchannel_skb);
void
recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb)
{
if (bch->rcount >= 64) {
printk(KERN_WARNING "B-channel %p receive queue overflow, "
"flushing!\n", bch);
skb_queue_purge(&bch->rqueue);
bch->rcount = 0;
}
bch->rcount++;
skb_queue_tail(&bch->rqueue, skb);
schedule_event(bch, FLG_RECVQUEUE);
}
EXPORT_SYMBOL(recv_Bchannel_skb);
static void
confirm_Dsend(struct dchannel *dch)
{
struct sk_buff *skb;
skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb),
0, NULL, GFP_ATOMIC);
if (!skb) {
printk(KERN_ERR "%s: no skb id %x\n", __func__,
mISDN_HEAD_ID(dch->tx_skb));
return;
}
skb_queue_tail(&dch->rqueue, skb);
schedule_event(dch, FLG_RECVQUEUE);
}
int
get_next_dframe(struct dchannel *dch)
{
dch->tx_idx = 0;
dch->tx_skb = skb_dequeue(&dch->squeue);
if (dch->tx_skb) {
confirm_Dsend(dch);
return 1;
}
dch->tx_skb = NULL;
test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
return 0;
}
EXPORT_SYMBOL(get_next_dframe);
static void
confirm_Bsend(struct bchannel *bch)
{
struct sk_buff *skb;
if (bch->rcount >= 64) {
printk(KERN_WARNING "B-channel %p receive queue overflow, "
"flushing!\n", bch);
skb_queue_purge(&bch->rqueue);
bch->rcount = 0;
}
skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb),
0, NULL, GFP_ATOMIC);
if (!skb) {
printk(KERN_ERR "%s: no skb id %x\n", __func__,
mISDN_HEAD_ID(bch->tx_skb));
return;
}
bch->rcount++;
skb_queue_tail(&bch->rqueue, skb);
schedule_event(bch, FLG_RECVQUEUE);
}
int
get_next_bframe(struct bchannel *bch)
{
bch->tx_idx = 0;
if (test_bit(FLG_TX_NEXT, &bch->Flags)) {
bch->tx_skb = bch->next_skb;
if (bch->tx_skb) {
bch->next_skb = NULL;
test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
/* confirm imediately to allow next data */
confirm_Bsend(bch);
return 1;
} else {
test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
printk(KERN_WARNING "B TX_NEXT without skb\n");
}
}
bch->tx_skb = NULL;
test_and_clear_bit(FLG_TX_BUSY, &bch->Flags);
return 0;
}
EXPORT_SYMBOL(get_next_bframe);
void
queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb)
{
struct mISDNhead *hh;
if (!skb) {
_queue_data(ch, pr, id, 0, NULL, GFP_ATOMIC);
} else {
if (ch->peer) {
hh = mISDN_HEAD_P(skb);
hh->prim = pr;
hh->id = id;
if (!ch->recv(ch->peer, skb))
return;
}
dev_kfree_skb(skb);
}
}
EXPORT_SYMBOL(queue_ch_frame);
int
dchannel_senddata(struct dchannel *ch, struct sk_buff *skb)
{
/* check oversize */
if (skb->len <= 0) {
printk(KERN_WARNING "%s: skb too small\n", __func__);
return -EINVAL;
}
if (skb->len > ch->maxlen) {
printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
__func__, skb->len, ch->maxlen);
return -EINVAL;
}
/* HW lock must be obtained */
if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
skb_queue_tail(&ch->squeue, skb);
return 0;
} else {
/* write to fifo */
ch->tx_skb = skb;
ch->tx_idx = 0;
return 1;
}
}
EXPORT_SYMBOL(dchannel_senddata);
int
bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
{
/* check oversize */
if (skb->len <= 0) {
printk(KERN_WARNING "%s: skb too small\n", __func__);
return -EINVAL;
}
if (skb->len > ch->maxlen) {
printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
__func__, skb->len, ch->maxlen);
return -EINVAL;
}
/* HW lock must be obtained */
/* check for pending next_skb */
if (ch->next_skb) {
printk(KERN_WARNING
"%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n",
__func__, skb->len, ch->next_skb->len);
return -EBUSY;
}
if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
test_and_set_bit(FLG_TX_NEXT, &ch->Flags);
ch->next_skb = skb;
return 0;
} else {
/* write to fifo */
ch->tx_skb = skb;
ch->tx_idx = 0;
confirm_Bsend(ch);
return 1;
}
}
EXPORT_SYMBOL(bchannel_senddata);
/* The function allocates a new receive skb on demand with a size for the
* requirements of the current protocol. It returns the tailroom of the
* receive skb or an error.
*/
int
bchannel_get_rxbuf(struct bchannel *bch, int reqlen)
{
int len;
if (bch->rx_skb) {
len = skb_tailroom(bch->rx_skb);
if (len < reqlen) {
pr_warning("B%d no space for %d (only %d) bytes\n",
bch->nr, reqlen, len);
if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
/* send what we have now and try a new buffer */
recv_Bchannel(bch, 0, true);
} else {
/* on HDLC we have to drop too big frames */
return -EMSGSIZE;
}
} else {
return len;
}
}
/* update current min/max length first */
if (unlikely(bch->maxlen != bch->next_maxlen))
bch->maxlen = bch->next_maxlen;
if (unlikely(bch->minlen != bch->next_minlen))
bch->minlen = bch->next_minlen;
if (unlikely(reqlen > bch->maxlen))
return -EMSGSIZE;
if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
if (reqlen >= bch->minlen) {
len = reqlen;
} else {
len = 2 * bch->minlen;
if (len > bch->maxlen)
len = bch->maxlen;
}
} else {
/* with HDLC we do not know the length yet */
len = bch->maxlen;
}
bch->rx_skb = mI_alloc_skb(len, GFP_ATOMIC);
if (!bch->rx_skb) {
pr_warning("B%d receive no memory for %d bytes\n",
bch->nr, len);
len = -ENOMEM;
}
return len;
}
EXPORT_SYMBOL(bchannel_get_rxbuf);