linux/drivers/isdn/mISDN/hwchannel.c
Linus Torvalds 033d9959ed Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo:
 "This is workqueue updates for v3.7-rc1.  A lot of activities this
  round including considerable API and behavior cleanups.

   * delayed_work combines a timer and a work item.  The handling of the
     timer part has always been a bit clunky leading to confusing
     cancelation API with weird corner-case behaviors.  delayed_work is
     updated to use new IRQ safe timer and cancelation now works as
     expected.

   * Another deficiency of delayed_work was lack of the counterpart of
     mod_timer() which led to cancel+queue combinations or open-coded
     timer+work usages.  mod_delayed_work[_on]() are added.

     These two delayed_work changes make delayed_work provide interface
     and behave like timer which is executed with process context.

   * A work item could be executed concurrently on multiple CPUs, which
     is rather unintuitive and made flush_work() behavior confusing and
     half-broken under certain circumstances.  This problem doesn't
     exist for non-reentrant workqueues.  While non-reentrancy check
     isn't free, the overhead is incurred only when a work item bounces
     across different CPUs and even in simulated pathological scenario
     the overhead isn't too high.

     All workqueues are made non-reentrant.  This removes the
     distinction between flush_[delayed_]work() and
     flush_[delayed_]_work_sync().  The former is now as strong as the
     latter and the specified work item is guaranteed to have finished
     execution of any previous queueing on return.

   * In addition to the various bug fixes, Lai redid and simplified CPU
     hotplug handling significantly.

   * Joonsoo introduced system_highpri_wq and used it during CPU
     hotplug.

  There are two merge commits - one to pull in IRQ safe timer from
  tip/timers/core and the other to pull in CPU hotplug fixes from
  wq/for-3.6-fixes as Lai's hotplug restructuring depended on them."

Fixed a number of trivial conflicts, but the more interesting conflicts
were silent ones where the deprecated interfaces had been used by new
code in the merge window, and thus didn't cause any real data conflicts.

Tejun pointed out a few of them, I fixed a couple more.

* 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits)
  workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending()
  workqueue: use cwq_set_max_active() helper for workqueue_set_max_active()
  workqueue: introduce cwq_set_max_active() helper for thaw_workqueues()
  workqueue: remove @delayed from cwq_dec_nr_in_flight()
  workqueue: fix possible stall on try_to_grab_pending() of a delayed work item
  workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback()
  workqueue: use __cpuinit instead of __devinit for cpu callbacks
  workqueue: rename manager_mutex to assoc_mutex
  workqueue: WORKER_REBIND is no longer necessary for idle rebinding
  workqueue: WORKER_REBIND is no longer necessary for busy rebinding
  workqueue: reimplement idle worker rebinding
  workqueue: deprecate __cancel_delayed_work()
  workqueue: reimplement cancel_delayed_work() using try_to_grab_pending()
  workqueue: use mod_delayed_work() instead of __cancel + queue
  workqueue: use irqsafe timer for delayed_work
  workqueue: clean up delayed_work initializers and add missing one
  workqueue: make deferrable delayed_work initializer names consistent
  workqueue: cosmetic whitespace updates for macro definitions
  workqueue: deprecate system_nrt[_freezable]_wq
  workqueue: deprecate flush[_delayed]_work_sync()
  ...
2012-10-02 09:54:49 -07:00

527 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;
skb_queue_purge(&ch->rqueue);
ch->rcount = 0;
}
EXPORT_SYMBOL(mISDN_clear_bchannel);
void
mISDN_freebchannel(struct bchannel *ch)
{
cancel_work_sync(&ch->workq);
mISDN_clear_bchannel(ch);
}
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);