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Message-Id: <1337161868-19399-6-git-send-email-kkeil@linux-pingi.de>
Date: Wed, 16 May 2012 11:51:05 +0200
From: Karsten Keil <kkeil@...ux-pingi.de>
To: David Miller <davem@...emloft.net>
Cc: netdev@...r.kernel.org
Subject: [PATCH v2 5/8] mISDN: Reduce RX buffer allocation for transparent data
We did allways allocate maxsize buffers, but for transparent data we know
the actual size.
Use a common function to calculate size and detect overflows.
Signed-off-by: Karsten Keil <kkeil@...ux-pingi.de>
---
drivers/isdn/hardware/mISDN/avmfritz.c | 18 ++-----
drivers/isdn/hardware/mISDN/hfcmulti.c | 61 ++++++++++--------------
drivers/isdn/hardware/mISDN/hfcpci.c | 11 ++--
drivers/isdn/hardware/mISDN/hfcsusb.c | 52 +++++++++-----------
drivers/isdn/hardware/mISDN/mISDNipac.c | 20 +++-----
drivers/isdn/hardware/mISDN/mISDNisar.c | 37 +++++----------
drivers/isdn/hardware/mISDN/netjet.c | 79 +++++++++++++-----------------
drivers/isdn/hardware/mISDN/w6692.c | 20 +++-----
drivers/isdn/mISDN/hwchannel.c | 75 ++++++++++++++++++++++++-----
include/linux/mISDNhw.h | 1 +
10 files changed, 186 insertions(+), 188 deletions(-)
diff --git a/drivers/isdn/hardware/mISDN/avmfritz.c b/drivers/isdn/hardware/mISDN/avmfritz.c
index cc78264..8081367 100644
--- a/drivers/isdn/hardware/mISDN/avmfritz.c
+++ b/drivers/isdn/hardware/mISDN/avmfritz.c
@@ -404,21 +404,14 @@ hdlc_empty_fifo(struct bchannel *bch, int count)
u32 *ptr;
u8 *p;
u32 val, addr;
- int cnt = 0;
+ int cnt;
struct fritzcard *fc = bch->hw;
pr_debug("%s: %s %d\n", fc->name, __func__, count);
- if (!bch->rx_skb) {
- bch->rx_skb = mI_alloc_skb(bch->maxlen, GFP_ATOMIC);
- if (!bch->rx_skb) {
- pr_info("%s: B receive out of memory\n",
- fc->name);
- return;
- }
- }
- if ((bch->rx_skb->len + count) > bch->maxlen) {
- pr_debug("%s: overrun %d\n", fc->name,
- bch->rx_skb->len + count);
+ cnt = bchannel_get_rxbuf(bch, count);
+ if (cnt < 0) {
+ pr_warning("%s.B%d: No bufferspace for %d bytes\n",
+ fc->name, bch->nr, count);
return;
}
p = skb_put(bch->rx_skb, count);
@@ -430,6 +423,7 @@ hdlc_empty_fifo(struct bchannel *bch, int count)
addr = fc->addr + CHIP_WINDOW;
outl(bch->nr == 2 ? AVM_HDLC_2 : AVM_HDLC_1, fc->addr);
}
+ cnt = 0;
while (cnt < count) {
val = le32_to_cpu(inl(addr));
put_unaligned(val, ptr);
diff --git a/drivers/isdn/hardware/mISDN/hfcmulti.c b/drivers/isdn/hardware/mISDN/hfcmulti.c
index bcb2b8e..16bef01 100644
--- a/drivers/isdn/hardware/mISDN/hfcmulti.c
+++ b/drivers/isdn/hardware/mISDN/hfcmulti.c
@@ -2196,24 +2196,20 @@ hfcmulti_rx(struct hfc_multi *hc, int ch)
int f1 = 0, f2 = 0; /* = 0, to make GCC happy */
int again = 0;
struct bchannel *bch;
- struct dchannel *dch;
+ struct dchannel *dch = NULL;
struct sk_buff *skb, **sp = NULL;
int maxlen;
bch = hc->chan[ch].bch;
- dch = hc->chan[ch].dch;
- if ((!dch) && (!bch))
- return;
- if (dch) {
+ if (bch) {
+ if (!test_bit(FLG_ACTIVE, &bch->Flags))
+ return;
+ } else if (hc->chan[ch].dch) {
+ dch = hc->chan[ch].dch;
if (!test_bit(FLG_ACTIVE, &dch->Flags))
return;
- sp = &dch->rx_skb;
- maxlen = dch->maxlen;
} else {
- if (!test_bit(FLG_ACTIVE, &bch->Flags))
- return;
- sp = &bch->rx_skb;
- maxlen = bch->maxlen;
+ return;
}
next_frame:
/* on first AND before getting next valid frame, R_FIFO must be written
@@ -2260,13 +2256,26 @@ next_frame:
if (Zsize <= 0)
return;
- if (*sp == NULL) {
- *sp = mI_alloc_skb(maxlen + 3, GFP_ATOMIC);
- if (*sp == NULL) {
- printk(KERN_DEBUG "%s: No mem for rx_skb\n",
- __func__);
+ if (bch) {
+ maxlen = bchannel_get_rxbuf(bch, Zsize);
+ if (maxlen < 0) {
+ pr_warning("card%d.B%d: No bufferspace for %d bytes\n",
+ hc->id + 1, bch->nr, Zsize);
return;
}
+ sp = &bch->rx_skb;
+ maxlen = bch->maxlen;
+ } else { /* Dchannel */
+ sp = &dch->rx_skb;
+ maxlen = dch->maxlen + 3;
+ if (*sp == NULL) {
+ *sp = mI_alloc_skb(maxlen, GFP_ATOMIC);
+ if (*sp == NULL) {
+ pr_warning("card%d: No mem for dch rx_skb\n",
+ hc->id + 1);
+ return;
+ }
+ }
}
/* show activity */
if (dch)
@@ -2281,7 +2290,7 @@ next_frame:
Zsize, z1, z2, (f1 == f2) ? "fragment" : "COMPLETE",
f1, f2, Zsize + (*sp)->len, again);
/* HDLC */
- if ((Zsize + (*sp)->len) > (maxlen + 3)) {
+ if ((Zsize + (*sp)->len) > maxlen) {
if (debug & DEBUG_HFCMULTI_FIFO)
printk(KERN_DEBUG
"%s(card %d): hdlc-frame too large.\n",
@@ -2351,24 +2360,7 @@ next_frame:
/* there is an incomplete frame */
} else {
/* transparent */
- if (Zsize > skb_tailroom(*sp))
- Zsize = skb_tailroom(*sp);
hc->read_fifo(hc, skb_put(*sp, Zsize), Zsize);
- if (((*sp)->len) < MISDN_COPY_SIZE) {
- skb = *sp;
- *sp = mI_alloc_skb(skb->len, GFP_ATOMIC);
- if (*sp) {
- memcpy(skb_put(*sp, skb->len),
- skb->data, skb->len);
- skb_trim(skb, 0);
- } else {
- printk(KERN_DEBUG "%s: No mem\n", __func__);
- *sp = skb;
- skb = NULL;
- }
- } else {
- skb = NULL;
- }
if (debug & DEBUG_HFCMULTI_FIFO)
printk(KERN_DEBUG
"%s(card %d): fifo(%d) reading %d bytes "
@@ -2376,7 +2368,6 @@ next_frame:
__func__, hc->id + 1, ch, Zsize, z1, z2);
/* only bch is transparent */
recv_Bchannel(bch, hc->chan[ch].Zfill);
- *sp = skb;
}
}
diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c
index 123e8e5..0622e05 100644
--- a/drivers/isdn/hardware/mISDN/hfcpci.c
+++ b/drivers/isdn/hardware/mISDN/hfcpci.c
@@ -577,8 +577,11 @@ hfcpci_empty_fifo_trans(struct bchannel *bch, struct bzfifo *rxbz,
fcnt_tx = B_FIFO_SIZE - fcnt_tx;
/* remaining bytes to send (bytes in tx-fifo) */
- bch->rx_skb = mI_alloc_skb(fcnt_rx, GFP_ATOMIC);
- if (bch->rx_skb) {
+ maxlen = bchannel_get_rxbuf(bch, fcnt_rx);
+ if (maxlen < 0) {
+ pr_warning("B%d: No bufferspace for %d bytes\n",
+ bch->nr, fcnt_rx);
+ } else {
ptr = skb_put(bch->rx_skb, fcnt_rx);
if (le16_to_cpu(*z2r) + fcnt_rx <= B_FIFO_SIZE + B_SUB_VAL)
maxlen = fcnt_rx; /* complete transfer */
@@ -597,9 +600,7 @@ hfcpci_empty_fifo_trans(struct bchannel *bch, struct bzfifo *rxbz,
memcpy(ptr, ptr1, fcnt_rx); /* rest */
}
recv_Bchannel(bch, fcnt_tx); /* bch, id */
- } else
- printk(KERN_WARNING "HFCPCI: receive out of memory\n");
-
+ }
*z2r = cpu_to_le16(new_z2); /* new position */
}
diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c
index 919eccc..6bb689b 100644
--- a/drivers/isdn/hardware/mISDN/hfcsusb.c
+++ b/drivers/isdn/hardware/mISDN/hfcsusb.c
@@ -860,7 +860,16 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
hdlc = 1;
}
if (fifo->bch) {
+ maxlen = bchannel_get_rxbuf(fifo->bch, len);
rx_skb = fifo->bch->rx_skb;
+ if (maxlen < 0) {
+ if (rx_skb)
+ skb_trim(rx_skb, 0);
+ pr_warning("%s.B%d: No bufferspace for %d bytes\n",
+ hw->name, fifo->bch->nr, len);
+ spin_unlock(&hw->lock);
+ return;
+ }
maxlen = fifo->bch->maxlen;
hdlc = test_bit(FLG_HDLC, &fifo->bch->Flags);
}
@@ -870,25 +879,22 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
hdlc = 1;
}
- if (!rx_skb) {
- rx_skb = mI_alloc_skb(maxlen, GFP_ATOMIC);
- if (rx_skb) {
- if (fifo->dch)
- fifo->dch->rx_skb = rx_skb;
- if (fifo->bch)
- fifo->bch->rx_skb = rx_skb;
- if (fifo->ech)
- fifo->ech->rx_skb = rx_skb;
- skb_trim(rx_skb, 0);
- } else {
- printk(KERN_DEBUG "%s: %s: No mem for rx_skb\n",
- hw->name, __func__);
- spin_unlock(&hw->lock);
- return;
- }
- }
-
if (fifo->dch || fifo->ech) {
+ if (!rx_skb) {
+ rx_skb = mI_alloc_skb(maxlen, GFP_ATOMIC);
+ if (rx_skb) {
+ if (fifo->dch)
+ fifo->dch->rx_skb = rx_skb;
+ if (fifo->ech)
+ fifo->ech->rx_skb = rx_skb;
+ skb_trim(rx_skb, 0);
+ } else {
+ printk(KERN_DEBUG "%s: %s: No mem for rx_skb\n",
+ hw->name, __func__);
+ spin_unlock(&hw->lock);
+ return;
+ }
+ }
/* D/E-Channel SKB range check */
if ((rx_skb->len + len) >= MAX_DFRAME_LEN_L1) {
printk(KERN_DEBUG "%s: %s: sbk mem exceeded "
@@ -898,16 +904,6 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
spin_unlock(&hw->lock);
return;
}
- } else if (fifo->bch) {
- /* B-Channel SKB range check */
- if ((rx_skb->len + len) >= (MAX_BCH_SIZE + 3)) {
- printk(KERN_DEBUG "%s: %s: sbk mem exceeded "
- "for fifo(%d) HFCUSB_B_RX\n",
- hw->name, __func__, fifon);
- skb_trim(rx_skb, 0);
- spin_unlock(&hw->lock);
- return;
- }
}
memcpy(skb_put(rx_skb, len), data, len);
diff --git a/drivers/isdn/hardware/mISDN/mISDNipac.c b/drivers/isdn/hardware/mISDN/mISDNipac.c
index e4b6d8d..7d109ed 100644
--- a/drivers/isdn/hardware/mISDN/mISDNipac.c
+++ b/drivers/isdn/hardware/mISDN/mISDNipac.c
@@ -933,22 +933,16 @@ static void
hscx_empty_fifo(struct hscx_hw *hscx, u8 count)
{
u8 *p;
+ int maxlen;
pr_debug("%s: B%1d %d\n", hscx->ip->name, hscx->bch.nr, count);
- if (!hscx->bch.rx_skb) {
- hscx->bch.rx_skb = mI_alloc_skb(hscx->bch.maxlen, GFP_ATOMIC);
- if (!hscx->bch.rx_skb) {
- pr_info("%s: B receive out of memory\n",
- hscx->ip->name);
- hscx_cmdr(hscx, 0x80); /* RMC */
- return;
- }
- }
- if ((hscx->bch.rx_skb->len + count) > hscx->bch.maxlen) {
- pr_debug("%s: overrun %d\n", hscx->ip->name,
- hscx->bch.rx_skb->len + count);
- skb_trim(hscx->bch.rx_skb, 0);
+ maxlen = bchannel_get_rxbuf(&hscx->bch, count);
+ if (maxlen < 0) {
hscx_cmdr(hscx, 0x80); /* RMC */
+ if (hscx->bch.rx_skb)
+ skb_trim(hscx->bch.rx_skb, 0);
+ pr_warning("%s.B%d: No bufferspace for %d bytes\n",
+ hscx->ip->name, hscx->bch.nr, count);
return;
}
p = skb_put(hscx->bch.rx_skb, count);
diff --git a/drivers/isdn/hardware/mISDN/mISDNisar.c b/drivers/isdn/hardware/mISDN/mISDNisar.c
index 9deea88..4169bb2 100644
--- a/drivers/isdn/hardware/mISDN/mISDNisar.c
+++ b/drivers/isdn/hardware/mISDN/mISDNisar.c
@@ -421,7 +421,8 @@ deliver_status(struct isar_ch *ch, int status)
static inline void
isar_rcv_frame(struct isar_ch *ch)
{
- u8 *ptr;
+ u8 *ptr;
+ int maxlen;
if (!ch->is->clsb) {
pr_debug("%s; ISAR zero len frame\n", ch->is->name);
@@ -437,36 +438,22 @@ isar_rcv_frame(struct isar_ch *ch)
case ISDN_P_B_RAW:
case ISDN_P_B_L2DTMF:
case ISDN_P_B_MODEM_ASYNC:
- if (!ch->bch.rx_skb) {
- ch->bch.rx_skb = mI_alloc_skb(ch->bch.maxlen,
- GFP_ATOMIC);
- if (unlikely(!ch->bch.rx_skb)) {
- pr_info("%s: B receive out of memory\n",
- ch->is->name);
- ch->is->write_reg(ch->is->hw, ISAR_IIA, 0);
- break;
- }
+ maxlen = bchannel_get_rxbuf(&ch->bch, ch->is->clsb);
+ if (maxlen < 0) {
+ pr_warning("%s.B%d: No bufferspace for %d bytes\n",
+ ch->is->name, ch->bch.nr, ch->is->clsb);
+ ch->is->write_reg(ch->is->hw, ISAR_IIA, 0);
+ break;
}
rcv_mbox(ch->is, skb_put(ch->bch.rx_skb, ch->is->clsb));
recv_Bchannel(&ch->bch, 0);
break;
case ISDN_P_B_HDLC:
- if (!ch->bch.rx_skb) {
- ch->bch.rx_skb = mI_alloc_skb(ch->bch.maxlen,
- GFP_ATOMIC);
- if (unlikely(!ch->bch.rx_skb)) {
- pr_info("%s: B receive out of memory\n",
- ch->is->name);
- ch->is->write_reg(ch->is->hw, ISAR_IIA, 0);
- break;
- }
- }
- if ((ch->bch.rx_skb->len + ch->is->clsb) >
- (ch->bch.maxlen + 2)) {
- pr_debug("%s: incoming packet too large\n",
- ch->is->name);
+ maxlen = bchannel_get_rxbuf(&ch->bch, ch->is->clsb);
+ if (maxlen < 0) {
+ pr_warning("%s.B%d: No bufferspace for %d bytes\n",
+ ch->is->name, ch->bch.nr, ch->is->clsb);
ch->is->write_reg(ch->is->hw, ISAR_IIA, 0);
- skb_trim(ch->bch.rx_skb, 0);
break;
}
if (ch->is->cmsb & HDLC_ERROR) {
diff --git a/drivers/isdn/hardware/mISDN/netjet.c b/drivers/isdn/hardware/mISDN/netjet.c
index da13b07..3f28057 100644
--- a/drivers/isdn/hardware/mISDN/netjet.c
+++ b/drivers/isdn/hardware/mISDN/netjet.c
@@ -386,24 +386,16 @@ read_dma(struct tiger_ch *bc, u32 idx, int cnt)
bc->bch.nr, idx);
}
bc->lastrx = idx;
- if (!bc->bch.rx_skb) {
- bc->bch.rx_skb = mI_alloc_skb(bc->bch.maxlen, GFP_ATOMIC);
- if (!bc->bch.rx_skb) {
- pr_info("%s: B%1d receive out of memory\n",
- card->name, bc->bch.nr);
- return;
- }
+ stat = bchannel_get_rxbuf(&bc->bch, cnt);
+ /* only transparent use the count here, HDLC overun is detected later */
+ if (stat == ENOMEM) {
+ pr_warning("%s.B%d: No memory for %d bytes\n",
+ card->name, bc->bch.nr, cnt);
+ return;
}
-
- if (test_bit(FLG_TRANSPARENT, &bc->bch.Flags)) {
- if ((bc->bch.rx_skb->len + cnt) > bc->bch.maxlen) {
- pr_debug("%s: B%1d overrun %d\n", card->name,
- bc->bch.nr, bc->bch.rx_skb->len + cnt);
- skb_trim(bc->bch.rx_skb, 0);
- return;
- }
+ if (test_bit(FLG_TRANSPARENT, &bc->bch.Flags))
p = skb_put(bc->bch.rx_skb, cnt);
- } else
+ else
p = bc->hrbuf;
for (i = 0; i < cnt; i++) {
@@ -414,48 +406,45 @@ read_dma(struct tiger_ch *bc, u32 idx, int cnt)
idx = 0;
p[i] = val & 0xff;
}
+
+ if (test_bit(FLG_TRANSPARENT, &bc->bch.Flags)) {
+ recv_Bchannel(&bc->bch, 0);
+ return;
+ }
+
pn = bc->hrbuf;
-next_frame:
- if (test_bit(FLG_HDLC, &bc->bch.Flags)) {
+ while (cnt > 0) {
stat = isdnhdlc_decode(&bc->hrecv, pn, cnt, &i,
bc->bch.rx_skb->data, bc->bch.maxlen);
- if (stat > 0) /* valid frame received */
+ if (stat > 0) { /* valid frame received */
p = skb_put(bc->bch.rx_skb, stat);
- else if (stat == -HDLC_CRC_ERROR)
+ if (debug & DEBUG_HW_BFIFO) {
+ snprintf(card->log, LOG_SIZE,
+ "B%1d-recv %s %d ", bc->bch.nr,
+ card->name, stat);
+ print_hex_dump_bytes(card->log,
+ DUMP_PREFIX_OFFSET, p,
+ stat);
+ }
+ recv_Bchannel(&bc->bch, 0);
+ stat = bchannel_get_rxbuf(&bc->bch, bc->bch.maxlen);
+ if (stat < 0) {
+ pr_warning("%s.B%d: No memory for %d bytes\n",
+ card->name, bc->bch.nr, cnt);
+ return;
+ }
+ } else if (stat == -HDLC_CRC_ERROR) {
pr_info("%s: B%1d receive frame CRC error\n",
card->name, bc->bch.nr);
- else if (stat == -HDLC_FRAMING_ERROR)
+ } else if (stat == -HDLC_FRAMING_ERROR) {
pr_info("%s: B%1d receive framing error\n",
card->name, bc->bch.nr);
- else if (stat == -HDLC_LENGTH_ERROR)
+ } else if (stat == -HDLC_LENGTH_ERROR) {
pr_info("%s: B%1d receive frame too long (> %d)\n",
card->name, bc->bch.nr, bc->bch.maxlen);
- } else
- stat = cnt;
-
- if (stat > 0) {
- if (debug & DEBUG_HW_BFIFO) {
- snprintf(card->log, LOG_SIZE, "B%1d-recv %s %d ",
- bc->bch.nr, card->name, stat);
- print_hex_dump_bytes(card->log, DUMP_PREFIX_OFFSET,
- p, stat);
}
- recv_Bchannel(&bc->bch, 0);
- }
- if (test_bit(FLG_HDLC, &bc->bch.Flags)) {
pn += i;
cnt -= i;
- if (!bc->bch.rx_skb) {
- bc->bch.rx_skb = mI_alloc_skb(bc->bch.maxlen,
- GFP_ATOMIC);
- if (!bc->bch.rx_skb) {
- pr_info("%s: B%1d receive out of memory\n",
- card->name, bc->bch.nr);
- return;
- }
- }
- if (cnt > 0)
- goto next_frame;
}
}
diff --git a/drivers/isdn/hardware/mISDN/w6692.c b/drivers/isdn/hardware/mISDN/w6692.c
index f1c0bf1..8324b20 100644
--- a/drivers/isdn/hardware/mISDN/w6692.c
+++ b/drivers/isdn/hardware/mISDN/w6692.c
@@ -465,6 +465,7 @@ W6692_empty_Bfifo(struct w6692_ch *wch, int count)
{
struct w6692_hw *card = wch->bch.hw;
u8 *ptr;
+ int maxlen;
pr_debug("%s: empty_Bfifo %d\n", card->name, count);
if (unlikely(wch->bch.state == ISDN_P_NONE)) {
@@ -474,20 +475,13 @@ W6692_empty_Bfifo(struct w6692_ch *wch, int count)
skb_trim(wch->bch.rx_skb, 0);
return;
}
- if (!wch->bch.rx_skb) {
- wch->bch.rx_skb = mI_alloc_skb(wch->bch.maxlen, GFP_ATOMIC);
- if (unlikely(!wch->bch.rx_skb)) {
- pr_info("%s: B receive out of memory\n", card->name);
- WriteW6692B(wch, W_B_CMDR, W_B_CMDR_RACK |
- W_B_CMDR_RACT);
- return;
- }
- }
- if (wch->bch.rx_skb->len + count > wch->bch.maxlen) {
- pr_debug("%s: empty_Bfifo incoming packet too large\n",
- card->name);
+ maxlen = bchannel_get_rxbuf(&wch->bch, count);
+ if (maxlen < 0) {
WriteW6692B(wch, W_B_CMDR, W_B_CMDR_RACK | W_B_CMDR_RACT);
- skb_trim(wch->bch.rx_skb, 0);
+ if (wch->bch.rx_skb)
+ skb_trim(wch->bch.rx_skb, 0);
+ pr_warning("%s.B%d: No bufferspace for %d bytes\n",
+ card->name, wch->bch.nr, count);
return;
}
ptr = skb_put(wch->bch.rx_skb, count);
diff --git a/drivers/isdn/mISDN/hwchannel.c b/drivers/isdn/mISDN/hwchannel.c
index 5c5ab47..3c2145d 100644
--- a/drivers/isdn/mISDN/hwchannel.c
+++ b/drivers/isdn/mISDN/hwchannel.c
@@ -201,20 +201,30 @@ recv_Bchannel(struct bchannel *bch, unsigned int id)
{
struct mISDNhead *hh;
- hh = mISDN_HEAD_P(bch->rx_skb);
- hh->prim = PH_DATA_IND;
- hh->id = id;
- if (bch->rcount >= 64) {
- printk(KERN_WARNING "B-channel %p receive queue overflow, "
- "flushing!\n", bch);
- skb_queue_purge(&bch->rqueue);
- bch->rcount = 0;
+ /* 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 {
+ 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);
}
- bch->rcount++;
- skb_queue_tail(&bch->rqueue, bch->rx_skb);
- bch->rx_skb = NULL;
- schedule_event(bch, FLG_RECVQUEUE);
}
EXPORT_SYMBOL(recv_Bchannel);
@@ -399,3 +409,44 @@ bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
}
}
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);
+ } else {
+ /* on HDLC we have to drop too big frames */
+ return -EMSGSIZE;
+ }
+ } else {
+ return len;
+ }
+ }
+ if (unlikely(reqlen > bch->maxlen))
+ return -EMSGSIZE;
+ if (test_bit(FLG_TRANSPARENT, &bch->Flags))
+ len = reqlen;
+ 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);
diff --git a/include/linux/mISDNhw.h b/include/linux/mISDNhw.h
index 491afd6..a86d86b 100644
--- a/include/linux/mISDNhw.h
+++ b/include/linux/mISDNhw.h
@@ -177,6 +177,7 @@ extern void queue_ch_frame(struct mISDNchannel *, u_int,
int, struct sk_buff *);
extern int dchannel_senddata(struct dchannel *, struct sk_buff *);
extern int bchannel_senddata(struct bchannel *, struct sk_buff *);
+extern int bchannel_get_rxbuf(struct bchannel *, int);
extern void recv_Dchannel(struct dchannel *);
extern void recv_Echannel(struct dchannel *, struct dchannel *);
extern void recv_Bchannel(struct bchannel *, unsigned int id);
--
1.7.3.4
--
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