diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/isdn/mISDN/hwchannel.c | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/drivers/isdn/mISDN/hwchannel.c b/drivers/isdn/mISDN/hwchannel.c new file mode 100644 index 000000000..8c93af06e --- /dev/null +++ b/drivers/isdn/mISDN/hwchannel.c @@ -0,0 +1,516 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Author Karsten Keil <kkeil@novell.com> + * + * Copyright 2008 by Karsten Keil <kkeil@novell.com> + */ + +#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_warn("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_warn("B%d receive no memory for %d bytes\n", bch->nr, len); + len = -ENOMEM; + } + return len; +} +EXPORT_SYMBOL(bchannel_get_rxbuf); |