diff options
author | Karsten Keil <kkeil@linux-pingi.de> | 2012-05-15 23:51:05 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-05-16 19:23:28 (GMT) |
commit | 7206e659f689558b41aa058c3040b081cb281d03 (patch) | |
tree | 2be5bdef5a0bbb9c5763b8c1b1e6fe04b7184cc5 /drivers | |
parent | 37952cfa3afdfa5cec39d9d76e80bc3a0e6a910c (diff) | |
download | linux-7206e659f689558b41aa058c3040b081cb281d03.tar.xz |
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@linux-pingi.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/isdn/hardware/mISDN/avmfritz.c | 18 | ||||
-rw-r--r-- | drivers/isdn/hardware/mISDN/hfcmulti.c | 61 | ||||
-rw-r--r-- | drivers/isdn/hardware/mISDN/hfcpci.c | 11 | ||||
-rw-r--r-- | drivers/isdn/hardware/mISDN/hfcsusb.c | 52 | ||||
-rw-r--r-- | drivers/isdn/hardware/mISDN/mISDNipac.c | 20 | ||||
-rw-r--r-- | drivers/isdn/hardware/mISDN/mISDNisar.c | 37 | ||||
-rw-r--r-- | drivers/isdn/hardware/mISDN/netjet.c | 79 | ||||
-rw-r--r-- | drivers/isdn/hardware/mISDN/w6692.c | 20 | ||||
-rw-r--r-- | drivers/isdn/mISDN/hwchannel.c | 75 |
9 files changed, 185 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 ab3d298..60dd6ef 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..4169bb2d 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); |