linux/drivers/isdn/mISDN/stack.c
Arnd Bergmann 1a19eb753a misdn: kill big kernel lock
The use of the big kernel lock in misdn is completely
bogus, so let's just remove it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-15 19:29:56 -07:00

657 lines
16 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/slab.h>
#include <linux/mISDNif.h>
#include <linux/kthread.h>
#include "core.h"
static u_int *debug;
static inline void
_queue_message(struct mISDNstack *st, struct sk_buff *skb)
{
struct mISDNhead *hh = mISDN_HEAD_P(skb);
if (*debug & DEBUG_QUEUE_FUNC)
printk(KERN_DEBUG "%s prim(%x) id(%x) %p\n",
__func__, hh->prim, hh->id, skb);
skb_queue_tail(&st->msgq, skb);
if (likely(!test_bit(mISDN_STACK_STOPPED, &st->status))) {
test_and_set_bit(mISDN_STACK_WORK, &st->status);
wake_up_interruptible(&st->workq);
}
}
static int
mISDN_queue_message(struct mISDNchannel *ch, struct sk_buff *skb)
{
_queue_message(ch->st, skb);
return 0;
}
static struct mISDNchannel *
get_channel4id(struct mISDNstack *st, u_int id)
{
struct mISDNchannel *ch;
mutex_lock(&st->lmutex);
list_for_each_entry(ch, &st->layer2, list) {
if (id == ch->nr)
goto unlock;
}
ch = NULL;
unlock:
mutex_unlock(&st->lmutex);
return ch;
}
static void
send_socklist(struct mISDN_sock_list *sl, struct sk_buff *skb)
{
struct hlist_node *node;
struct sock *sk;
struct sk_buff *cskb = NULL;
read_lock(&sl->lock);
sk_for_each(sk, node, &sl->head) {
if (sk->sk_state != MISDN_BOUND)
continue;
if (!cskb)
cskb = skb_copy(skb, GFP_KERNEL);
if (!cskb) {
printk(KERN_WARNING "%s no skb\n", __func__);
break;
}
if (!sock_queue_rcv_skb(sk, cskb))
cskb = NULL;
}
read_unlock(&sl->lock);
if (cskb)
dev_kfree_skb(cskb);
}
static void
send_layer2(struct mISDNstack *st, struct sk_buff *skb)
{
struct sk_buff *cskb;
struct mISDNhead *hh = mISDN_HEAD_P(skb);
struct mISDNchannel *ch;
int ret;
if (!st)
return;
mutex_lock(&st->lmutex);
if ((hh->id & MISDN_ID_ADDR_MASK) == MISDN_ID_ANY) { /* L2 for all */
list_for_each_entry(ch, &st->layer2, list) {
if (list_is_last(&ch->list, &st->layer2)) {
cskb = skb;
skb = NULL;
} else {
cskb = skb_copy(skb, GFP_KERNEL);
}
if (cskb) {
ret = ch->send(ch, cskb);
if (ret) {
if (*debug & DEBUG_SEND_ERR)
printk(KERN_DEBUG
"%s ch%d prim(%x) addr(%x)"
" err %d\n",
__func__, ch->nr,
hh->prim, ch->addr, ret);
dev_kfree_skb(cskb);
}
} else {
printk(KERN_WARNING "%s ch%d addr %x no mem\n",
__func__, ch->nr, ch->addr);
goto out;
}
}
} else {
list_for_each_entry(ch, &st->layer2, list) {
if ((hh->id & MISDN_ID_ADDR_MASK) == ch->addr) {
ret = ch->send(ch, skb);
if (!ret)
skb = NULL;
goto out;
}
}
ret = st->dev->teimgr->ctrl(st->dev->teimgr, CHECK_DATA, skb);
if (!ret)
skb = NULL;
else if (*debug & DEBUG_SEND_ERR)
printk(KERN_DEBUG
"%s ch%d mgr prim(%x) addr(%x) err %d\n",
__func__, ch->nr, hh->prim, ch->addr, ret);
}
out:
mutex_unlock(&st->lmutex);
if (skb)
dev_kfree_skb(skb);
}
static inline int
send_msg_to_layer(struct mISDNstack *st, struct sk_buff *skb)
{
struct mISDNhead *hh = mISDN_HEAD_P(skb);
struct mISDNchannel *ch;
int lm;
lm = hh->prim & MISDN_LAYERMASK;
if (*debug & DEBUG_QUEUE_FUNC)
printk(KERN_DEBUG "%s prim(%x) id(%x) %p\n",
__func__, hh->prim, hh->id, skb);
if (lm == 0x1) {
if (!hlist_empty(&st->l1sock.head)) {
__net_timestamp(skb);
send_socklist(&st->l1sock, skb);
}
return st->layer1->send(st->layer1, skb);
} else if (lm == 0x2) {
if (!hlist_empty(&st->l1sock.head))
send_socklist(&st->l1sock, skb);
send_layer2(st, skb);
return 0;
} else if (lm == 0x4) {
ch = get_channel4id(st, hh->id);
if (ch)
return ch->send(ch, skb);
else
printk(KERN_WARNING
"%s: dev(%s) prim(%x) id(%x) no channel\n",
__func__, dev_name(&st->dev->dev), hh->prim,
hh->id);
} else if (lm == 0x8) {
WARN_ON(lm == 0x8);
ch = get_channel4id(st, hh->id);
if (ch)
return ch->send(ch, skb);
else
printk(KERN_WARNING
"%s: dev(%s) prim(%x) id(%x) no channel\n",
__func__, dev_name(&st->dev->dev), hh->prim,
hh->id);
} else {
/* broadcast not handled yet */
printk(KERN_WARNING "%s: dev(%s) prim %x not delivered\n",
__func__, dev_name(&st->dev->dev), hh->prim);
}
return -ESRCH;
}
static void
do_clear_stack(struct mISDNstack *st)
{
}
static int
mISDNStackd(void *data)
{
struct mISDNstack *st = data;
int err = 0;
sigfillset(&current->blocked);
if (*debug & DEBUG_MSG_THREAD)
printk(KERN_DEBUG "mISDNStackd %s started\n",
dev_name(&st->dev->dev));
if (st->notify != NULL) {
complete(st->notify);
st->notify = NULL;
}
for (;;) {
struct sk_buff *skb;
if (unlikely(test_bit(mISDN_STACK_STOPPED, &st->status))) {
test_and_clear_bit(mISDN_STACK_WORK, &st->status);
test_and_clear_bit(mISDN_STACK_RUNNING, &st->status);
} else
test_and_set_bit(mISDN_STACK_RUNNING, &st->status);
while (test_bit(mISDN_STACK_WORK, &st->status)) {
skb = skb_dequeue(&st->msgq);
if (!skb) {
test_and_clear_bit(mISDN_STACK_WORK,
&st->status);
/* test if a race happens */
skb = skb_dequeue(&st->msgq);
if (!skb)
continue;
test_and_set_bit(mISDN_STACK_WORK,
&st->status);
}
#ifdef MISDN_MSG_STATS
st->msg_cnt++;
#endif
err = send_msg_to_layer(st, skb);
if (unlikely(err)) {
if (*debug & DEBUG_SEND_ERR)
printk(KERN_DEBUG
"%s: %s prim(%x) id(%x) "
"send call(%d)\n",
__func__, dev_name(&st->dev->dev),
mISDN_HEAD_PRIM(skb),
mISDN_HEAD_ID(skb), err);
dev_kfree_skb(skb);
continue;
}
if (unlikely(test_bit(mISDN_STACK_STOPPED,
&st->status))) {
test_and_clear_bit(mISDN_STACK_WORK,
&st->status);
test_and_clear_bit(mISDN_STACK_RUNNING,
&st->status);
break;
}
}
if (test_bit(mISDN_STACK_CLEARING, &st->status)) {
test_and_set_bit(mISDN_STACK_STOPPED, &st->status);
test_and_clear_bit(mISDN_STACK_RUNNING, &st->status);
do_clear_stack(st);
test_and_clear_bit(mISDN_STACK_CLEARING, &st->status);
test_and_set_bit(mISDN_STACK_RESTART, &st->status);
}
if (test_and_clear_bit(mISDN_STACK_RESTART, &st->status)) {
test_and_clear_bit(mISDN_STACK_STOPPED, &st->status);
test_and_set_bit(mISDN_STACK_RUNNING, &st->status);
if (!skb_queue_empty(&st->msgq))
test_and_set_bit(mISDN_STACK_WORK,
&st->status);
}
if (test_bit(mISDN_STACK_ABORT, &st->status))
break;
if (st->notify != NULL) {
complete(st->notify);
st->notify = NULL;
}
#ifdef MISDN_MSG_STATS
st->sleep_cnt++;
#endif
test_and_clear_bit(mISDN_STACK_ACTIVE, &st->status);
wait_event_interruptible(st->workq, (st->status &
mISDN_STACK_ACTION_MASK));
if (*debug & DEBUG_MSG_THREAD)
printk(KERN_DEBUG "%s: %s wake status %08lx\n",
__func__, dev_name(&st->dev->dev), st->status);
test_and_set_bit(mISDN_STACK_ACTIVE, &st->status);
test_and_clear_bit(mISDN_STACK_WAKEUP, &st->status);
if (test_bit(mISDN_STACK_STOPPED, &st->status)) {
test_and_clear_bit(mISDN_STACK_RUNNING, &st->status);
#ifdef MISDN_MSG_STATS
st->stopped_cnt++;
#endif
}
}
#ifdef MISDN_MSG_STATS
printk(KERN_DEBUG "mISDNStackd daemon for %s proceed %d "
"msg %d sleep %d stopped\n",
dev_name(&st->dev->dev), st->msg_cnt, st->sleep_cnt,
st->stopped_cnt);
printk(KERN_DEBUG
"mISDNStackd daemon for %s utime(%ld) stime(%ld)\n",
dev_name(&st->dev->dev), st->thread->utime, st->thread->stime);
printk(KERN_DEBUG
"mISDNStackd daemon for %s nvcsw(%ld) nivcsw(%ld)\n",
dev_name(&st->dev->dev), st->thread->nvcsw, st->thread->nivcsw);
printk(KERN_DEBUG "mISDNStackd daemon for %s killed now\n",
dev_name(&st->dev->dev));
#endif
test_and_set_bit(mISDN_STACK_KILLED, &st->status);
test_and_clear_bit(mISDN_STACK_RUNNING, &st->status);
test_and_clear_bit(mISDN_STACK_ACTIVE, &st->status);
test_and_clear_bit(mISDN_STACK_ABORT, &st->status);
skb_queue_purge(&st->msgq);
st->thread = NULL;
if (st->notify != NULL) {
complete(st->notify);
st->notify = NULL;
}
return 0;
}
static int
l1_receive(struct mISDNchannel *ch, struct sk_buff *skb)
{
if (!ch->st)
return -ENODEV;
__net_timestamp(skb);
_queue_message(ch->st, skb);
return 0;
}
void
set_channel_address(struct mISDNchannel *ch, u_int sapi, u_int tei)
{
ch->addr = sapi | (tei << 8);
}
void
__add_layer2(struct mISDNchannel *ch, struct mISDNstack *st)
{
list_add_tail(&ch->list, &st->layer2);
}
void
add_layer2(struct mISDNchannel *ch, struct mISDNstack *st)
{
mutex_lock(&st->lmutex);
__add_layer2(ch, st);
mutex_unlock(&st->lmutex);
}
static int
st_own_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
{
if (!ch->st || !ch->st->layer1)
return -EINVAL;
return ch->st->layer1->ctrl(ch->st->layer1, cmd, arg);
}
int
create_stack(struct mISDNdevice *dev)
{
struct mISDNstack *newst;
int err;
DECLARE_COMPLETION_ONSTACK(done);
newst = kzalloc(sizeof(struct mISDNstack), GFP_KERNEL);
if (!newst) {
printk(KERN_ERR "kmalloc mISDN_stack failed\n");
return -ENOMEM;
}
newst->dev = dev;
INIT_LIST_HEAD(&newst->layer2);
INIT_HLIST_HEAD(&newst->l1sock.head);
rwlock_init(&newst->l1sock.lock);
init_waitqueue_head(&newst->workq);
skb_queue_head_init(&newst->msgq);
mutex_init(&newst->lmutex);
dev->D.st = newst;
err = create_teimanager(dev);
if (err) {
printk(KERN_ERR "kmalloc teimanager failed\n");
kfree(newst);
return err;
}
dev->teimgr->peer = &newst->own;
dev->teimgr->recv = mISDN_queue_message;
dev->teimgr->st = newst;
newst->layer1 = &dev->D;
dev->D.recv = l1_receive;
dev->D.peer = &newst->own;
newst->own.st = newst;
newst->own.ctrl = st_own_ctrl;
newst->own.send = mISDN_queue_message;
newst->own.recv = mISDN_queue_message;
if (*debug & DEBUG_CORE_FUNC)
printk(KERN_DEBUG "%s: st(%s)\n", __func__,
dev_name(&newst->dev->dev));
newst->notify = &done;
newst->thread = kthread_run(mISDNStackd, (void *)newst, "mISDN_%s",
dev_name(&newst->dev->dev));
if (IS_ERR(newst->thread)) {
err = PTR_ERR(newst->thread);
printk(KERN_ERR
"mISDN:cannot create kernel thread for %s (%d)\n",
dev_name(&newst->dev->dev), err);
delete_teimanager(dev->teimgr);
kfree(newst);
} else
wait_for_completion(&done);
return err;
}
int
connect_layer1(struct mISDNdevice *dev, struct mISDNchannel *ch,
u_int protocol, struct sockaddr_mISDN *adr)
{
struct mISDN_sock *msk = container_of(ch, struct mISDN_sock, ch);
struct channel_req rq;
int err;
if (*debug & DEBUG_CORE_FUNC)
printk(KERN_DEBUG "%s: %s proto(%x) adr(%d %d %d %d)\n",
__func__, dev_name(&dev->dev), protocol, adr->dev,
adr->channel, adr->sapi, adr->tei);
switch (protocol) {
case ISDN_P_NT_S0:
case ISDN_P_NT_E1:
case ISDN_P_TE_S0:
case ISDN_P_TE_E1:
ch->recv = mISDN_queue_message;
ch->peer = &dev->D.st->own;
ch->st = dev->D.st;
rq.protocol = protocol;
rq.adr.channel = adr->channel;
err = dev->D.ctrl(&dev->D, OPEN_CHANNEL, &rq);
printk(KERN_DEBUG "%s: ret %d (dev %d)\n", __func__, err,
dev->id);
if (err)
return err;
write_lock_bh(&dev->D.st->l1sock.lock);
sk_add_node(&msk->sk, &dev->D.st->l1sock.head);
write_unlock_bh(&dev->D.st->l1sock.lock);
break;
default:
return -ENOPROTOOPT;
}
return 0;
}
int
connect_Bstack(struct mISDNdevice *dev, struct mISDNchannel *ch,
u_int protocol, struct sockaddr_mISDN *adr)
{
struct channel_req rq, rq2;
int pmask, err;
struct Bprotocol *bp;
if (*debug & DEBUG_CORE_FUNC)
printk(KERN_DEBUG "%s: %s proto(%x) adr(%d %d %d %d)\n",
__func__, dev_name(&dev->dev), protocol,
adr->dev, adr->channel, adr->sapi,
adr->tei);
ch->st = dev->D.st;
pmask = 1 << (protocol & ISDN_P_B_MASK);
if (pmask & dev->Bprotocols) {
rq.protocol = protocol;
rq.adr = *adr;
err = dev->D.ctrl(&dev->D, OPEN_CHANNEL, &rq);
if (err)
return err;
ch->recv = rq.ch->send;
ch->peer = rq.ch;
rq.ch->recv = ch->send;
rq.ch->peer = ch;
rq.ch->st = dev->D.st;
} else {
bp = get_Bprotocol4mask(pmask);
if (!bp)
return -ENOPROTOOPT;
rq2.protocol = protocol;
rq2.adr = *adr;
rq2.ch = ch;
err = bp->create(&rq2);
if (err)
return err;
ch->recv = rq2.ch->send;
ch->peer = rq2.ch;
rq2.ch->st = dev->D.st;
rq.protocol = rq2.protocol;
rq.adr = *adr;
err = dev->D.ctrl(&dev->D, OPEN_CHANNEL, &rq);
if (err) {
rq2.ch->ctrl(rq2.ch, CLOSE_CHANNEL, NULL);
return err;
}
rq2.ch->recv = rq.ch->send;
rq2.ch->peer = rq.ch;
rq.ch->recv = rq2.ch->send;
rq.ch->peer = rq2.ch;
rq.ch->st = dev->D.st;
}
ch->protocol = protocol;
ch->nr = rq.ch->nr;
return 0;
}
int
create_l2entity(struct mISDNdevice *dev, struct mISDNchannel *ch,
u_int protocol, struct sockaddr_mISDN *adr)
{
struct channel_req rq;
int err;
if (*debug & DEBUG_CORE_FUNC)
printk(KERN_DEBUG "%s: %s proto(%x) adr(%d %d %d %d)\n",
__func__, dev_name(&dev->dev), protocol,
adr->dev, adr->channel, adr->sapi,
adr->tei);
rq.protocol = ISDN_P_TE_S0;
if (dev->Dprotocols & (1 << ISDN_P_TE_E1))
rq.protocol = ISDN_P_TE_E1;
switch (protocol) {
case ISDN_P_LAPD_NT:
rq.protocol = ISDN_P_NT_S0;
if (dev->Dprotocols & (1 << ISDN_P_NT_E1))
rq.protocol = ISDN_P_NT_E1;
case ISDN_P_LAPD_TE:
ch->recv = mISDN_queue_message;
ch->peer = &dev->D.st->own;
ch->st = dev->D.st;
rq.adr.channel = 0;
err = dev->D.ctrl(&dev->D, OPEN_CHANNEL, &rq);
printk(KERN_DEBUG "%s: ret 1 %d\n", __func__, err);
if (err)
break;
rq.protocol = protocol;
rq.adr = *adr;
rq.ch = ch;
err = dev->teimgr->ctrl(dev->teimgr, OPEN_CHANNEL, &rq);
printk(KERN_DEBUG "%s: ret 2 %d\n", __func__, err);
if (!err) {
if ((protocol == ISDN_P_LAPD_NT) && !rq.ch)
break;
add_layer2(rq.ch, dev->D.st);
rq.ch->recv = mISDN_queue_message;
rq.ch->peer = &dev->D.st->own;
rq.ch->ctrl(rq.ch, OPEN_CHANNEL, NULL); /* can't fail */
}
break;
default:
err = -EPROTONOSUPPORT;
}
return err;
}
void
delete_channel(struct mISDNchannel *ch)
{
struct mISDN_sock *msk = container_of(ch, struct mISDN_sock, ch);
struct mISDNchannel *pch;
if (!ch->st) {
printk(KERN_WARNING "%s: no stack\n", __func__);
return;
}
if (*debug & DEBUG_CORE_FUNC)
printk(KERN_DEBUG "%s: st(%s) protocol(%x)\n", __func__,
dev_name(&ch->st->dev->dev), ch->protocol);
if (ch->protocol >= ISDN_P_B_START) {
if (ch->peer) {
ch->peer->ctrl(ch->peer, CLOSE_CHANNEL, NULL);
ch->peer = NULL;
}
return;
}
switch (ch->protocol) {
case ISDN_P_NT_S0:
case ISDN_P_TE_S0:
case ISDN_P_NT_E1:
case ISDN_P_TE_E1:
write_lock_bh(&ch->st->l1sock.lock);
sk_del_node_init(&msk->sk);
write_unlock_bh(&ch->st->l1sock.lock);
ch->st->dev->D.ctrl(&ch->st->dev->D, CLOSE_CHANNEL, NULL);
break;
case ISDN_P_LAPD_TE:
pch = get_channel4id(ch->st, ch->nr);
if (pch) {
mutex_lock(&ch->st->lmutex);
list_del(&pch->list);
mutex_unlock(&ch->st->lmutex);
pch->ctrl(pch, CLOSE_CHANNEL, NULL);
pch = ch->st->dev->teimgr;
pch->ctrl(pch, CLOSE_CHANNEL, NULL);
} else
printk(KERN_WARNING "%s: no l2 channel\n",
__func__);
break;
case ISDN_P_LAPD_NT:
pch = ch->st->dev->teimgr;
if (pch) {
pch->ctrl(pch, CLOSE_CHANNEL, NULL);
} else
printk(KERN_WARNING "%s: no l2 channel\n",
__func__);
break;
default:
break;
}
return;
}
void
delete_stack(struct mISDNdevice *dev)
{
struct mISDNstack *st = dev->D.st;
DECLARE_COMPLETION_ONSTACK(done);
if (*debug & DEBUG_CORE_FUNC)
printk(KERN_DEBUG "%s: st(%s)\n", __func__,
dev_name(&st->dev->dev));
if (dev->teimgr)
delete_teimanager(dev->teimgr);
if (st->thread) {
if (st->notify) {
printk(KERN_WARNING "%s: notifier in use\n",
__func__);
complete(st->notify);
}
st->notify = &done;
test_and_set_bit(mISDN_STACK_ABORT, &st->status);
test_and_set_bit(mISDN_STACK_WAKEUP, &st->status);
wake_up_interruptible(&st->workq);
wait_for_completion(&done);
}
if (!list_empty(&st->layer2))
printk(KERN_WARNING "%s: layer2 list not empty\n",
__func__);
if (!hlist_empty(&st->l1sock.head))
printk(KERN_WARNING "%s: layer1 list not empty\n",
__func__);
kfree(st);
}
void
mISDN_initstack(u_int *dp)
{
debug = dp;
}