drivers/staging/cxt1e1/musycc.c

static unsigned int max_intcnt;
static unsigned int max_bh;

/*-----------------------------------------------------------------------------
 * musycc.c -
 *
 * Copyright (C) 2007  One Stop Systems, Inc.
 * Copyright (C) 2003-2006  SBE, Inc.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   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.
 *
 * For further information, contact via email: support@onestopsystems.com
 * One Stop Systems, Inc.  Escondido, California  U.S.A.
 *-----------------------------------------------------------------------------
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include "pmcc4_sysdep.h"
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include "sbecom_inline_linux.h"
#include "libsbew.h"
#include "pmcc4_private.h"
#include "pmcc4.h"
#include "musycc.h"

#define sd_find_chan(ci,ch)   c4_find_chan(ch)


/*******************************************************************/
/* global driver variables */
extern ci_t *c4_list;
extern int  drvr_state;

extern int  cxt1e1_max_mru;
extern int  cxt1e1_max_mtu;
extern int  max_rxdesc_used;
extern int  max_txdesc_used;
extern ci_t *CI;                /* dummy pointr to board ZEROE's data - DEBUG
				 * USAGE */


/*******************************************************************/
/* forward references */
void        c4_fifo_free(mpi_t *, int);
void        c4_wk_chan_restart(mch_t *);
void        musycc_bh_tx_eom(mpi_t *, int);
int         musycc_chan_up(ci_t *, int);
status_t __init musycc_init(ci_t *);
void        musycc_intr_bh_tasklet(ci_t *);
void        musycc_serv_req(mpi_t *, u_int32_t);
void        musycc_update_timeslots(mpi_t *);

/*******************************************************************/

static int
musycc_dump_rxbuffer_ring(mch_t *ch, int lockit)
{
	struct mdesc *m;
	unsigned long flags = 0;

	u_int32_t status;
	int         n;

#ifdef RLD_DUMP_BUFDATA
	u_int32_t *dp;
	int len = 0;
#endif
	if (lockit)
		spin_lock_irqsave(&ch->ch_rxlock, flags);
	if (ch->rxd_num == 0)
		pr_info("  ZERO receive buffers allocated for this channel.");
	else {
		FLUSH_MEM_READ();
		m = &ch->mdr[ch->rxix_irq_srv];
		for (n = ch->rxd_num; n; n--) {
			status = le32_to_cpu(m->status);
			pr_info("%c  %08lx[%2d]: sts %08x (%c%c%c%c:%d.) Data [%08x] Next [%08x]\n",
				(m == &ch->mdr[ch->rxix_irq_srv]) ? 'F' : ' ',
				(unsigned long) m, n,
				status,
				m->data ? (status & HOST_RX_OWNED ? 'H' : 'M') : '-',
				status & POLL_DISABLED ? 'P' : '-',
				status & EOBIRQ_ENABLE ? 'b' : '-',
				status & EOMIRQ_ENABLE ? 'm' : '-',
				status & LENGTH_MASK,
				le32_to_cpu(m->data), le32_to_cpu(m->next));
#ifdef RLD_DUMP_BUFDATA
				len = status & LENGTH_MASK;

#if 1
				if (m->data && (status & HOST_RX_OWNED))
#else
				/* always dump regardless of valid RX data */
				if (m->data)
#endif
				{
					dp = (u_int32_t *)OS_phystov((void *)(le32_to_cpu(m->data)));
					if (len >= 0x10)
						pr_info("    %x[%x]: %08X %08X %08X %08x\n",
							(u_int32_t)dp, len,
							*dp, *(dp + 1),
							*(dp + 2), *(dp + 3));
					else if (len >= 0x08)
						pr_info("    %x[%x]: %08X %08X\n",
							(u_int32_t)dp, len,
							*dp, *(dp + 1));
					else
						pr_info("    %x[%x]: %08X\n",
							(u_int32_t)dp,
							len, *dp);
				}
#endif
			m = m->snext;
		}
	}
	pr_info("\n");

	if (lockit)
		spin_unlock_irqrestore(&ch->ch_rxlock, flags);
	return 0;
}

static int
musycc_dump_txbuffer_ring(mch_t *ch, int lockit)
{
	struct mdesc *m;
	unsigned long flags = 0;
	u_int32_t   status;
	int         n;
#ifdef RLD_DUMP_BUFDATA
	u_int32_t *dp;
	int len = 0;
#endif

	if (lockit)
		spin_lock_irqsave(&ch->ch_txlock, flags);
	if (ch->txd_num == 0)
		pr_info("  ZERO transmit buffers allocated for this channel.");
	else {
		FLUSH_MEM_READ();
		m = ch->txd_irq_srv;
		for (n = ch->txd_num; n; n--) {
			status = le32_to_cpu(m->status);
			pr_info("%c%c %08lx[%2d]: sts %08x (%c%c%c%c:%d.) Data [%08x] Next [%08x]\n",
				(m == ch->txd_usr_add) ? 'F' : ' ',
				(m == ch->txd_irq_srv) ? 'L' : ' ',
				(unsigned long) m, n,
				status,
				m->data ? (status & MUSYCC_TX_OWNED ? 'M' : 'H') : '-',
				status & POLL_DISABLED ? 'P' : '-',
				status & EOBIRQ_ENABLE ? 'b' : '-',
				status & EOMIRQ_ENABLE ? 'm' : '-',
				status & LENGTH_MASK,
				le32_to_cpu(m->data), le32_to_cpu(m->next));
#ifdef RLD_DUMP_BUFDATA
			len = status & LENGTH_MASK;

			if (m->data) {
				dp = (u_int32_t *)OS_phystov((void *)(le32_to_cpu(m->data)));
				if (len >= 0x10)
					pr_info("    %x[%x]: %08X %08X %08X %08x\n",
						(u_int32_t) dp, len,
						*dp, *(dp + 1),
						*(dp + 2), *(dp + 3));
				else if (len >= 0x08)
					pr_info("    %x[%x]: %08X %08X\n",
						(u_int32_t)dp, len,
						*dp, *(dp + 1));
				else
					pr_info("    %x[%x]: %08X\n",
						(u_int32_t)dp, len, *dp);
			}
#endif
			m = m->snext;
		}
	}                               /* -for- */
	pr_info("\n");

	if (lockit)
		spin_unlock_irqrestore(&ch->ch_txlock, flags);
	return 0;
}

/*
 * The following supports a backdoor debug facility which can be used to
 * display the state of a board's channel.
 */

status_t
musycc_dump_ring(ci_t *ci, unsigned int chan)
{
	mch_t      *ch;
	int bh;

	if (chan >= MAX_CHANS_USED)
		return SBE_DRVR_FAIL;       /* E2BIG */

	bh = atomic_read(&ci->bh_pending);
	pr_info(">> bh_pend %d [%d] ihead %d itail %d [%d] th_cnt %d bh_cnt %d wdcnt %d note %d\n",
		bh, max_bh, ci->iqp_headx, ci->iqp_tailx, max_intcnt,
		ci->intlog.drvr_intr_thcount,
		ci->intlog.drvr_intr_bhcount,
		ci->wdcount, ci->wd_notify);
	max_bh = 0;                 /* reset counter */
	max_intcnt = 0;             /* reset counter */

	ch = sd_find_chan(dummy, chan);
	if (!ch) {
		pr_info(">> musycc_dump_ring: channel %d not up.\n", chan);
		return ENOENT;
	}
	pr_info(">> CI %p CHANNEL %3d @ %p: state %x status/p %x/%x\n",
		ci, chan, ch, ch->state,
		ch->status, ch->p.status);
	pr_info("--------------------------------\n");
	pr_info("TX Buffer Ring - Channel %d, txd_num %d. (bd/ch pend %d %d), TXD required %d, txpkt %lu\n",
		chan, ch->txd_num,
		(u_int32_t)atomic_read(&ci->tx_pending),
		(u_int32_t)atomic_read(&ch->tx_pending),
		ch->txd_required, ch->s.tx_packets);
	pr_info("++ User 0x%p IRQ_SRV 0x%p USR_ADD 0x%p QStopped %x, start_tx %x tx_full %d txd_free %d mode %x\n",
		ch->user, ch->txd_irq_srv, ch->txd_usr_add,
		sd_queue_stopped(ch->user),
		ch->ch_start_tx, ch->tx_full, ch->txd_free, ch->p.chan_mode);
	musycc_dump_txbuffer_ring(ch, 1);
	pr_info("RX Buffer Ring - Channel %d, rxd_num %d. IRQ_SRV[%d] 0x%p, start_rx %x rxpkt %lu\n",
		chan, ch->rxd_num, ch->rxix_irq_srv,
		&ch->mdr[ch->rxix_irq_srv], ch->ch_start_rx, ch->s.rx_packets);
	musycc_dump_rxbuffer_ring(ch, 1);

	return SBE_DRVR_SUCCESS;
}


status_t
musycc_dump_rings(ci_t *ci, unsigned int start_chan)
{
	unsigned int chan;

	for (chan = start_chan; chan < (start_chan + 5); chan++)
		musycc_dump_ring(ci, chan);
	return SBE_DRVR_SUCCESS;
}


/*
 * NOTE on musycc_init_mdt():  These MUSYCC writes are only operational after
 * a MUSYCC GROUP_INIT command has been issued.
 */

void
musycc_init_mdt(mpi_t *pi)
{
	u_int32_t  *addr, cfg;
	int         i;

	/*
	 * This Idle Code insertion takes effect prior to channel's first
	 * transmitted  message.  After that, each message contains its own Idle
	 * Code information which is to be issued after the message is
	 * transmitted (Ref.MUSYCC 5.2.2.3: MCENBL bit in Group Configuration
	 * Descriptor).
	 */

	addr = (u_int32_t *) ((u_long) pi->reg + MUSYCC_MDT_BASE03_ADDR);
	cfg = CFG_CH_FLAG_7E << IDLE_CODE;

	for (i = 0; i < 32; addr++, i++)
		pci_write_32(addr, cfg);
}


/* Set TX thp to the next unprocessed md */

void
musycc_update_tx_thp(mch_t *ch)
{
	struct mdesc *md;
	unsigned long flags;

	spin_lock_irqsave(&ch->ch_txlock, flags);
	while (1) {
		md = ch->txd_irq_srv;
		FLUSH_MEM_READ();
		if (!md->data) {
			/* No MDs with buffers to process */
			spin_unlock_irqrestore(&ch->ch_txlock, flags);
			return;
		}
		if ((le32_to_cpu(md->status)) & MUSYCC_TX_OWNED) {
			/* this is the MD to restart TX with */
			break;
		}
		/*
		 * Otherwise, we have a valid, host-owned message descriptor which
		 * has been successfully transmitted and whose buffer can be freed,
		 * so... process this MD, it's owned by the host.  (This might give
		 * as a new, updated txd_irq_srv.)
		 */
		musycc_bh_tx_eom(ch->up, ch->gchan);
	}
	md = ch->txd_irq_srv;
	ch->up->regram->thp[ch->gchan] = cpu_to_le32(OS_vtophys(md));
	FLUSH_MEM_WRITE();

	if (ch->tx_full) {
		ch->tx_full = 0;
		ch->txd_required = 0;
		sd_enable_xmit(ch->user);  /* re-enable to catch flow controlled
					    * channel */
	}
	spin_unlock_irqrestore(&ch->ch_txlock, flags);

#ifdef RLD_TRANS_DEBUG
	pr_info("++ musycc_update_tx_thp[%d]: setting thp = %p, sts %x\n",
		ch->channum, md, md->status);
#endif
}


/*
 * This is the workq task executed by the OS when our queue_work() is
 * scheduled and run.  It can fire off either RX or TX ACTIVATION depending
 * upon the channel's ch_start_tx and ch_start_rx variables.  This routine
 * is implemented as a work queue so that the call to the service request is
 * able to sleep, awaiting an interrupt acknowledgment response (SACK) from
 * the hardware.
 */

void
musycc_wq_chan_restart(void *arg)      /* channel private structure */
{
	mch_t      *ch;
	mpi_t      *pi;
	struct mdesc *md;

#if defined(RLD_TRANS_DEBUG) || defined(RLD_RXACT_DEBUG)
	static int hereb4 = 7;
#endif

	ch = container_of(arg, struct c4_chan_info, ch_work);
	pi = ch->up;

#ifdef RLD_TRANS_DEBUG
	pr_info("wq_chan_restart[%d]: start_RT[%d/%d] status %x\n",
		ch->channum, ch->ch_start_rx, ch->ch_start_tx, ch->status);

#endif

	/**********************************/
	/** check for RX restart request **/
	/**********************************/

	if ((ch->ch_start_rx) && (ch->status & RX_ENABLED)) {

		ch->ch_start_rx = 0;
#if defined(RLD_TRANS_DEBUG) || defined(RLD_RXACT_DEBUG)
		if (hereb4) {            /* RLD DEBUG */
			hereb4--;
#ifdef RLD_TRANS_DEBUG
			md = &ch->mdr[ch->rxix_irq_srv];
			pr_info("++ musycc_wq_chan_restart[%d] CHAN RX ACTIVATE: rxix_irq_srv %d, md %p sts %x, rxpkt %lu\n",
				ch->channum, ch->rxix_irq_srv, md,
				le32_to_cpu(md->status), ch->s.rx_packets);
#elif defined(RLD_RXACT_DEBUG)
			md = &ch->mdr[ch->rxix_irq_srv];
			pr_info("++ musycc_wq_chan_restart[%d] CHAN RX ACTIVATE: rxix_irq_srv %d, md %p sts %x, rxpkt %lu\n",
				ch->channum, ch->rxix_irq_srv,
				md, le32_to_cpu(md->status),
				ch->s.rx_packets);
			musycc_dump_rxbuffer_ring(ch, 1);      /* RLD DEBUG */
#endif
		}
#endif
		musycc_serv_req(pi, SR_CHANNEL_ACTIVATE |
				SR_RX_DIRECTION | ch->gchan);
	}
	/**********************************/
	/** check for TX restart request **/
	/**********************************/

	if ((ch->ch_start_tx) && (ch->status & TX_ENABLED)) {
		/* find next unprocessed message, then set TX thp to it */
		musycc_update_tx_thp(ch);

		md = ch->txd_irq_srv;
		if (!md) {
#ifdef RLD_TRANS_DEBUG
			pr_info("-- musycc_wq_chan_restart[%d]: WARNING, starting NULL md\n",
				ch->channum);
#endif
		} else if (md->data && ((le32_to_cpu(md->status)) &
			   MUSYCC_TX_OWNED)) {
			ch->ch_start_tx = 0;

#ifdef RLD_TRANS_DEBUG
			pr_info("++ musycc_wq_chan_restart() CHAN TX ACTIVATE: chan %d txd_irq_srv %p = sts %x, txpkt %lu\n",
				ch->channum, ch->txd_irq_srv,
				ch->txd_irq_srv->status, ch->s.tx_packets);
#endif
			musycc_serv_req(pi, SR_CHANNEL_ACTIVATE |
					SR_TX_DIRECTION | ch->gchan);
		}
#ifdef RLD_RESTART_DEBUG
		else {
			/* retain request to start until retried and we have data to xmit */
			pr_info("-- musycc_wq_chan_restart[%d]: DELAYED due to md %p sts %x data %x, start_tx %x\n",
				ch->channum, md,
				le32_to_cpu(md->status),
				le32_to_cpu(md->data), ch->ch_start_tx);
			musycc_dump_txbuffer_ring(ch, 0);
		}
#endif
	}
}


 /*
  * Channel restart either fires of a workqueue request (2.6) or lodges a
  * watchdog activation sequence (2.4).
  */

void
musycc_chan_restart(mch_t *ch)
{
#ifdef RLD_RESTART_DEBUG
	pr_info("++ musycc_chan_restart[%d]: txd_irq_srv @ %p = sts %x\n",
		ch->channum, ch->txd_irq_srv, ch->txd_irq_srv->status);
#endif

	/* 2.6 - find next unprocessed message, then set TX thp to it */
#ifdef RLD_RESTART_DEBUG
	pr_info(">> musycc_chan_restart: scheduling Chan %x workQ @ %p\n",
		ch->channum, &ch->ch_work);
#endif
	c4_wk_chan_restart(ch);        /* work queue mechanism fires off: Ref:
					* musycc_wq_chan_restart () */
}


void
rld_put_led(mpi_t *pi, u_int32_t ledval)
{
	static u_int32_t led;

	if (ledval == 0)
		led = 0;
	else
		led |= ledval;

	/* RLD DEBUG TRANHANG */
	pci_write_32((u_int32_t *) &pi->up->cpldbase->leds, led);
}


#define MUSYCC_SR_RETRY_CNT  9

void
musycc_serv_req(mpi_t *pi, u_int32_t req)
{
	volatile u_int32_t r;
	int         rcnt;

	/*
	 * PORT NOTE: Semaphore protect service loop guarantees only a single
	 * operation at a time.  Per MUSYCC Manual - "Issuing service requests to
	 * the same channel group without first receiving ACK from each request
	 * may cause the host to lose track of which service request has been
	 * acknowledged."
	 */

	SD_SEM_TAKE(&pi->sr_sem_busy, "serv");     /* only 1 thru here, per
						    * group */

	if (pi->sr_last == req) {
#ifdef RLD_TRANS_DEBUG
		pr_info(">> same SR, Port %d Req %x\n", pi->portnum, req);
#endif

		/*
		 * The most likely repeated request is the channel activation command
		 * which follows the occurrence of a Transparent mode TX ONR or a
		 * BUFF error.  If the previous command was a CHANNEL ACTIVATE,
		 * precede it with a NOOP command in order maintain coherent control
		 * of this current (re)ACTIVATE.
		 */

		r = (pi->sr_last & ~SR_GCHANNEL_MASK);
		if ((r == (SR_CHANNEL_ACTIVATE | SR_TX_DIRECTION)) ||
		    (r == (SR_CHANNEL_ACTIVATE | SR_RX_DIRECTION))) {
#ifdef RLD_TRANS_DEBUG
			pr_info(">> same CHAN ACT SR, Port %d Req %x => issue SR_NOOP CMD\n", pi->portnum, req);
#endif
			/* allow this next request */
			SD_SEM_GIVE(&pi->sr_sem_busy);
			musycc_serv_req(pi, SR_NOOP);
			/* relock & continue w/ original req */
			SD_SEM_TAKE(&pi->sr_sem_busy, "serv");
		} else if (req == SR_NOOP) {
			/* no need to issue back-to-back
			 * SR_NOOP commands at this time
			 */
#ifdef RLD_TRANS_DEBUG
			pr_info(">> same Port SR_NOOP skipped, Port %d\n",
				pi->portnum);
#endif
			/* allow this next request */
			SD_SEM_GIVE(&pi->sr_sem_busy);
			return;
		}
	}
	rcnt = 0;
	pi->sr_last = req;
rewrite:
	pci_write_32((u_int32_t *) &pi->reg->srd, req);
	FLUSH_MEM_WRITE();

	/*
	 * Per MUSYCC Manual, Section 6.1,2 - "When writing an SCR service
	 * request, the host must ensure at least one PCI bus clock cycle has
	 * elapsed before writing another service request.  To meet this minimum
	 * elapsed service request write timing interval, it is recommended that
	 * the host follow any SCR write with another operation which reads from
	 * the same address."
	 */

	/* adhere to write timing imposition */
	r = pci_read_32((u_int32_t *) &pi->reg->srd);


	if ((r != req) && (req != SR_CHIP_RESET) &&
	    (++rcnt <= MUSYCC_SR_RETRY_CNT)) {
		if (cxt1e1_log_level >= LOG_MONITOR)
			pr_info("%s: %d - reissue srv req/last %x/%x (hdw reads %x), Chan %d.\n",
				pi->up->devname, rcnt, req, pi->sr_last, r,
				(pi->portnum * MUSYCC_NCHANS) + (req & 0x1f));
		/* this delay helps reduce reissue counts
		 * (reason not yet researched)
		 */
		OS_uwait_dummy();
		goto rewrite;
	}
	if (rcnt > MUSYCC_SR_RETRY_CNT) {
		pr_warning("%s: failed service request (#%d)= %x, group %d.\n",
			   pi->up->devname, MUSYCC_SR_RETRY_CNT,
			   req, pi->portnum);
		SD_SEM_GIVE(&pi->sr_sem_busy); /* allow any next request */
		return;
	}
	if (req == SR_CHIP_RESET) {
		/*
		 * PORT NOTE: the CHIP_RESET command is NOT ack'd by the MUSYCC, thus
		 * the upcoming delay is used.  Though the MUSYCC documentation
		 * suggests a read-after-write would supply the required delay, it's
		 * unclear what CPU/BUS clock speeds might have been assumed when
		 * suggesting this 'lack of ACK' workaround.  Thus the use of uwait.
		 */
		OS_uwait(100000, "icard"); /* 100ms */
	} else {
		FLUSH_MEM_READ();
		/* sleep until SACK interrupt occurs */
		SD_SEM_TAKE(&pi->sr_sem_wait, "sakack");
	}
	SD_SEM_GIVE(&pi->sr_sem_busy); /* allow any next request */
}


#ifdef  SBE_PMCC4_ENABLE
void
musycc_update_timeslots(mpi_t *pi)
{
	int         i, ch;
	char        e1mode = IS_FRAME_ANY_E1(pi->p.port_mode);

	for (i = 0; i < 32; i++) {
		int         usedby = 0, last = 0, ts, j, bits[8];

		u_int8_t lastval = 0;

		if (((i == 0) && e1mode) || /* disable if  E1 mode */
		    ((i == 16) && ((pi->p.port_mode == CFG_FRAME_E1CRC_CAS) ||
		    (pi->p.port_mode == CFG_FRAME_E1CRC_CAS_AMI))) ||
		    ((i > 23) && (!e1mode))) /* disable if T1 mode */
			/* make tslot unavailable for this mode */
			pi->tsm[i] = 0xff;
		else
			/* make tslot available for assignment */
			pi->tsm[i] = 0x00;
		for (j = 0; j < 8; j++)
			bits[j] = -1;
		for (ch = 0; ch < MUSYCC_NCHANS; ch++) {
			if ((pi->chan[ch]->state == UP) &&
			    (pi->chan[ch]->p.bitmask[i])) {
				usedby++;
				last = ch;
				lastval = pi->chan[ch]->p.bitmask[i];
				for (j = 0; j < 8; j++)
					if (lastval & (1 << j))
						bits[j] = ch;
				pi->tsm[i] |= lastval;
			}
		}
		if (!usedby)
			ts = 0;
		else if ((usedby == 1) && (lastval == 0xff))
			ts = (4 << 5) | last;
		else if ((usedby == 1) && (lastval == 0x7f))
			ts = (5 << 5) | last;
		else {
			int         idx;

			if (bits[0] < 0)
				ts = (6 << 5) | (idx = last);
			else
				ts = (7 << 5) | (idx = bits[0]);
			for (j = 1; j < 8; j++) {
				pi->regram->rscm[idx * 8 + j] =
					(bits[j] < 0) ? 0 : (0x80 | bits[j]);
				pi->regram->tscm[idx * 8 + j] =
					(bits[j] < 0) ? 0 : (0x80 | bits[j]);
			}
		}
		pi->regram->rtsm[i] = ts;
		pi->regram->ttsm[i] = ts;
	}
	FLUSH_MEM_WRITE();

	musycc_serv_req(pi, SR_TIMESLOT_MAP | SR_RX_DIRECTION);
	musycc_serv_req(pi, SR_TIMESLOT_MAP | SR_TX_DIRECTION);
	musycc_serv_req(pi, SR_SUBCHANNEL_MAP | SR_RX_DIRECTION);
	musycc_serv_req(pi, SR_SUBCHANNEL_MAP | SR_TX_DIRECTION);
}
#endif


#ifdef SBE_WAN256T3_ENABLE
	void
musycc_update_timeslots(mpi_t *pi)
{
	mch_t      *ch;

	u_int8_t    ts, hmask, tsen;
	int         gchan;
	int         i;

#ifdef SBE_PMCC4_ENABLE
	hmask = (0x1f << pi->up->p.hypersize) & 0x1f;
#endif
#ifdef SBE_WAN256T3_ENABLE
	hmask = (0x1f << hyperdummy) & 0x1f;
#endif
	for (i = 0; i < 128; i++) {
		gchan = ((pi->portnum * MUSYCC_NCHANS) +
			(i & hmask)) % MUSYCC_NCHANS;
		ch = pi->chan[gchan];
		if (ch->p.mode_56k)
			tsen = MODE_56KBPS;
		else
			tsen = MODE_64KBPS;     /* also the default */
		ts = ((pi->portnum % 4) == (i / 32)) ? (tsen << 5) | (i & hmask) : 0;
		pi->regram->rtsm[i] = ts;
		pi->regram->ttsm[i] = ts;
	}
	FLUSH_MEM_WRITE();
	musycc_serv_req(pi, SR_TIMESLOT_MAP | SR_RX_DIRECTION);
	musycc_serv_req(pi, SR_TIMESLOT_MAP | SR_TX_DIRECTION);
}
#endif


 /*
  * This routine converts a generic library channel configuration parameter
  * into a hardware specific register value (IE. MUSYCC CCD Register).
  */
u_int32_t
musycc_chan_proto(int proto)
{
	int         reg;

	switch (proto) {
	case CFG_CH_PROTO_TRANS:        /* 0 */
		reg = MUSYCC_CCD_TRANS;
		break;
	case CFG_CH_PROTO_SS7:          /* 1 */
		reg = MUSYCC_CCD_SS7;
		break;
	default:
	case CFG_CH_PROTO_ISLP_MODE:   /* 4 */
	case CFG_CH_PROTO_HDLC_FCS16:  /* 2 */
		reg = MUSYCC_CCD_HDLC_FCS16;
		break;
	case CFG_CH_PROTO_HDLC_FCS32:  /* 3 */
		reg = MUSYCC_CCD_HDLC_FCS32;
		break;
	}

	return reg;
}

#ifdef SBE_WAN256T3_ENABLE
static void __init
musycc_init_port(mpi_t *pi)
{
	pci_write_32((u_int32_t *) &pi->reg->gbp, OS_vtophys(pi->regram));

	pi->regram->grcd =
		__constant_cpu_to_le32(MUSYCC_GRCD_RX_ENABLE |
				       MUSYCC_GRCD_TX_ENABLE |
				       MUSYCC_GRCD_SF_ALIGN |
				       MUSYCC_GRCD_SUBCHAN_DISABLE |
				       MUSYCC_GRCD_OOFMP_DISABLE |
				       MUSYCC_GRCD_COFAIRQ_DISABLE |
				       MUSYCC_GRCD_MC_ENABLE |
				       (MUSYCC_GRCD_POLLTH_32 << MUSYCC_GRCD_POLLTH_SHIFT));

	pi->regram->pcd =
		__constant_cpu_to_le32(MUSYCC_PCD_E1X4_MODE |
				       MUSYCC_PCD_TXDATA_RISING |
				       MUSYCC_PCD_TX_DRIVEN);

	/* Message length descriptor */
	pi->regram->mld = __constant_cpu_to_le32(cxt1e1_max_mru | (cxt1e1_max_mru << 16));
	FLUSH_MEM_WRITE();

	musycc_serv_req(pi, SR_GROUP_INIT | SR_RX_DIRECTION);
	musycc_serv_req(pi, SR_GROUP_INIT | SR_TX_DIRECTION);

	musycc_init_mdt(pi);

	musycc_update_timeslots(pi);
}
#endif


status_t    __init
musycc_init(ci_t *ci)
{
	char       *regaddr;        /* temp for address boundary calculations */
	int         i, gchan;

	OS_sem_init(&ci->sem_wdbusy, SEM_AVAILABLE); /* watchdog exclusion */

	/*
	 * Per MUSYCC manual, Section 6.3.4 - "The host must allocate a dword
	 * aligned memory segment for interrupt queue pointers."
	 */

#define INT_QUEUE_BOUNDARY  4

	regaddr = kzalloc((INT_QUEUE_SIZE + 1) * sizeof(u_int32_t),
			  GFP_KERNEL | GFP_DMA);
	if (!regaddr)
		return -ENOMEM;
	ci->iqd_p_saved = regaddr;      /* save orig value for free's usage */
	/* this calculates closest boundary */
	ci->iqd_p = (u_int32_t *) ((unsigned long)(regaddr + INT_QUEUE_BOUNDARY - 1) &
				   (~(INT_QUEUE_BOUNDARY - 1)));

	for (i = 0; i < INT_QUEUE_SIZE; i++)
		ci->iqd_p[i] = __constant_cpu_to_le32(INT_EMPTY_ENTRY);

	for (i = 0; i < ci->max_port; i++) {
		mpi_t      *pi = &ci->port[i];

		/*
		 * Per MUSYCC manual, Section 6.3.2 - "The host must allocate a 2KB
		 * bound memory segment for Channel Group 0."
		 */

#define GROUP_BOUNDARY   0x800

		regaddr = kzalloc(sizeof(struct musycc_groupr) + GROUP_BOUNDARY,
				  GFP_KERNEL | GFP_DMA);
		if (!regaddr) {
			for (gchan = 0; gchan < i; gchan++) {
				pi = &ci->port[gchan];
				kfree(pi->reg);
				pi->reg = NULL;
			}
			return -ENOMEM;
		}
		pi->regram_saved = regaddr; /* save orig value for free's usage */
		/* this calculates closest boundary */
		pi->regram = (struct musycc_groupr *) ((unsigned long)(regaddr + GROUP_BOUNDARY - 1) &
				(~(GROUP_BOUNDARY - 1)));
	}

	/* any board centric MUSYCC commands will use group ZERO as its "home" */
	ci->regram = ci->port[0].regram;
	musycc_serv_req(&ci->port[0], SR_CHIP_RESET);

	pci_write_32((u_int32_t *) &ci->reg->gbp, OS_vtophys(ci->regram));
	pci_flush_write(ci);
#ifdef CONFIG_SBE_PMCC4_NCOMM
	ci->regram->__glcd = __constant_cpu_to_le32(GCD_MAGIC);
#else
	/* standard driver POLLS for INTB via CPLD register */
	ci->regram->__glcd = __constant_cpu_to_le32(GCD_MAGIC |
						    MUSYCC_GCD_INTB_DISABLE);
#endif

	ci->regram->__iqp = cpu_to_le32(OS_vtophys(&ci->iqd_p[0]));
	ci->regram->__iql = __constant_cpu_to_le32(INT_QUEUE_SIZE - 1);
	pci_write_32((u_int32_t *) &ci->reg->dacbp, 0);
	FLUSH_MEM_WRITE();

	ci->state = C_RUNNING;          /* mark as full interrupt processing
					 * available */

	musycc_serv_req(&ci->port[0], SR_GLOBAL_INIT); /* FIRST INTERRUPT ! */

	/* sanity check settable parameters */

	if (cxt1e1_max_mru > 0xffe) {
		pr_warning("Maximum allowed MRU exceeded, resetting %d to %d.\n",
			   cxt1e1_max_mru, 0xffe);
		cxt1e1_max_mru = 0xffe;
	}
	if (cxt1e1_max_mtu > 0xffe) {
		pr_warning("Maximum allowed MTU exceeded, resetting %d to %d.\n",
			   cxt1e1_max_mtu, 0xffe);
		cxt1e1_max_mtu = 0xffe;
	}
#ifdef SBE_WAN256T3_ENABLE
	for (i = 0; i < MUSYCC_NPORTS; i++)
		musycc_init_port(&ci->port[i]);
#endif

	return SBE_DRVR_SUCCESS;        /* no error */
}


void
musycc_bh_tx_eom(mpi_t *pi, int gchan)
{
	mch_t      *ch;
	struct mdesc *md;

	volatile u_int32_t status;

	ch = pi->chan[gchan];
	if (!ch || ch->state != UP) {
		if (cxt1e1_log_level >= LOG_ERROR)
			pr_info("%s: intr: xmit EOM on uninitialized channel %d\n",
				pi->up->devname, gchan);
	}
	if (!ch || !ch->mdt)
		return;                     /* note: mdt==0 implies a malloc()
					     * failure w/in chan_up() routine */

	do {
		FLUSH_MEM_READ();
		md = ch->txd_irq_srv;
		status = le32_to_cpu(md->status);

		/*
		 * Note: Per MUSYCC Ref 6.4.9, the host does not poll a host-owned
		 * Transmit Buffer Descriptor during Transparent Mode.
		 */
		if (status & MUSYCC_TX_OWNED) {
			int         readCount, loopCount;

			/***********************************************************/
			/* HW Bug Fix                                              */
			/* ----------                                              */
			/* Under certain PCI Bus loading conditions, the data      */
			/* associated with an update of Shared Memory is delayed   */
			/* relative to its PCI Interrupt.  This is caught when     */
			/* the host determines it does not yet OWN the descriptor. */
			/***********************************************************/

			readCount = 0;
			while (status & MUSYCC_TX_OWNED) {
				for (loopCount = 0; loopCount < 0x30; loopCount++)
					/* use call to avoid optimization
					 * removal of dummy delay */
					OS_uwait_dummy();
				FLUSH_MEM_READ();
				status = le32_to_cpu(md->status);
				if (readCount++ > 40)
					break; /* don't wait any longer */
			}
			if (status & MUSYCC_TX_OWNED) {
				if (cxt1e1_log_level >= LOG_MONITOR) {
					pr_info("%s: Port %d Chan %2d - unexpected TX msg ownership intr (md %p sts %x)\n",
						pi->up->devname, pi->portnum,
						ch->channum, md, status);
					pr_info("++ User 0x%p IRQ_SRV 0x%p USR_ADD 0x%p QStopped %x, start_tx %x tx_full %d txd_free %d mode %x\n",
						ch->user, ch->txd_irq_srv,
						ch->txd_usr_add,
						sd_queue_stopped(ch->user),
						ch->ch_start_tx, ch->tx_full,
						ch->txd_free, ch->p.chan_mode);
					musycc_dump_txbuffer_ring(ch, 0);
				}
				break;              /* Not our mdesc, done */
			} else {
				if (cxt1e1_log_level >= LOG_MONITOR)
					pr_info("%s: Port %d Chan %2d - recovered TX msg ownership [%d] (md %p sts %x)\n",
						pi->up->devname, pi->portnum,
						ch->channum, readCount,
						md, status);
			}
		}
		ch->txd_irq_srv = md->snext;

		md->data = 0;
		if (md->mem_token) {
			/* upcount channel */
			atomic_sub(OS_mem_token_tlen(md->mem_token),
				   &ch->tx_pending);
			/* upcount card */
			atomic_sub(OS_mem_token_tlen(md->mem_token),
				   &pi->up->tx_pending);
#ifdef SBE_WAN256T3_ENABLE
			if (!atomic_read(&pi->up->tx_pending))
				wan256t3_led(pi->up, LED_TX, 0);
#endif
			OS_mem_token_free_irq(md->mem_token);
			md->mem_token = NULL;
		}
		md->status = 0;
#ifdef RLD_TXFULL_DEBUG
		if (cxt1e1_log_level >= LOG_MONITOR2)
			pr_info("~~ tx_eom: tx_full %x  txd_free %d -> %d\n",
				ch->tx_full, ch->txd_free, ch->txd_free + 1);
#endif
		++ch->txd_free;
		FLUSH_MEM_WRITE();

		if ((ch->p.chan_mode != CFG_CH_PROTO_TRANS) &&
		    (status & EOBIRQ_ENABLE)) {
			if (cxt1e1_log_level >= LOG_MONITOR)
				pr_info("%s: Mode (%x) incorrect EOB status (%x)\n",
					pi->up->devname, ch->p.chan_mode,
					status);
			if ((status & EOMIRQ_ENABLE) == 0)
				break;
		}
	} while ((ch->p.chan_mode != CFG_CH_PROTO_TRANS) &&
		 ((status & EOMIRQ_ENABLE) == 0));
	/*
	 * NOTE: (The above 'while' is coupled w/ previous 'do', way above.) Each
	 * Transparent data buffer has the EOB bit, and NOT the EOM bit, set and
	 * will furthermore have a separate IQD associated with each messages
	 * buffer.
	 */

	FLUSH_MEM_READ();
	/*
	 * Smooth flow control hysterisis by maintaining task stoppage until half
	 * the available write buffers are available.
	 */
	if (ch->tx_full && (ch->txd_free >= (ch->txd_num / 2))) {
		/*
		 * Then, only releave task stoppage if we actually have enough
		 * buffers to service the last requested packet.  It may require MORE
		 * than half the available!
		 */
		if (ch->txd_free >= ch->txd_required) {

#ifdef RLD_TXFULL_DEBUG
			if (cxt1e1_log_level >= LOG_MONITOR2)
				pr_info("tx_eom[%d]: enable xmit tx_full no more, txd_free %d txd_num/2 %d\n",
					ch->channum,
					ch->txd_free, ch->txd_num / 2);
#endif
			ch->tx_full = 0;
			ch->txd_required = 0;
			/* re-enable to catch flow controlled channel */
			sd_enable_xmit(ch->user);
		}
	}
#ifdef RLD_TXFULL_DEBUG
	else if (ch->tx_full) {
		if (cxt1e1_log_level >= LOG_MONITOR2)
			pr_info("tx_eom[%d]: bypass TX enable though room available? (txd_free %d txd_num/2 %d)\n",
				ch->channum,
				ch->txd_free, ch->txd_num / 2);
	}
#endif

	FLUSH_MEM_WRITE();
}


static void
musycc_bh_rx_eom(mpi_t *pi, int gchan)
{
	mch_t      *ch;
	void       *m, *m2;
	struct mdesc *md;
	volatile u_int32_t status;
	u_int32_t   error;

	ch = pi->chan[gchan];
	if (!ch || ch->state != UP) {
		if (cxt1e1_log_level > LOG_ERROR)
			pr_info("%s: intr: receive EOM on uninitialized channel %d\n",
				pi->up->devname, gchan);
		return;
	}
	if (!ch->mdr)
		return;                     /* can this happen ? */

	for (;;) {
		FLUSH_MEM_READ();
		md = &ch->mdr[ch->rxix_irq_srv];
		status = le32_to_cpu(md->status);
		if (!(status & HOST_RX_OWNED))
			break;                  /* Not our mdesc, done */
		m = md->mem_token;
		error = (status >> 16) & 0xf;
		if (error == 0) {
			{
				m2 = OS_mem_token_alloc(cxt1e1_max_mru);
				if (m2) {
					/* substitute the mbuf+cluster */
					md->mem_token = m2;
					md->data = cpu_to_le32(OS_vtophys(
							       OS_mem_token_data(m2)));

					/* pass the received mbuf upward */
					sd_recv_consume(m, status & LENGTH_MASK,
							ch->user);
					ch->s.rx_packets++;
					ch->s.rx_bytes += status & LENGTH_MASK;
				} else
					ch->s.rx_dropped++;
			}
		} else if (error == ERR_FCS)
			ch->s.rx_crc_errors++;
		else if (error == ERR_ALIGN)
			ch->s.rx_missed_errors++;
		else if (error == ERR_ABT)
			ch->s.rx_missed_errors++;
		else if (error == ERR_LNG)
			ch->s.rx_length_errors++;
		else if (error == ERR_SHT)
			ch->s.rx_length_errors++;
		FLUSH_MEM_WRITE();
		status = cxt1e1_max_mru;
		if (ch->p.chan_mode == CFG_CH_PROTO_TRANS)
			status |= EOBIRQ_ENABLE;
		md->status = cpu_to_le32(status);

		/* Check next mdesc in the ring */
		if (++ch->rxix_irq_srv >= ch->rxd_num)
			ch->rxix_irq_srv = 0;
		FLUSH_MEM_WRITE();
	}
}


irqreturn_t
musycc_intr_th_handler(void *devp)
{
	ci_t       *ci = (ci_t *) devp;
	volatile u_int32_t status, currInt = 0;
	u_int32_t   nextInt, intCnt;

	/*
	 * Hardware not available, potential interrupt hang.  But since interrupt
	 * might be shared, just return.
	 */
	if (ci->state == C_INIT)
		return IRQ_NONE;
	/*
	 * Marked as hardware available. Don't service interrupts, just clear the
	 * event.
	 */

	if (ci->state == C_IDLE) {
		status = pci_read_32((u_int32_t *) &ci->reg->isd);

		/* clear the interrupt but process nothing else */
		pci_write_32((u_int32_t *) &ci->reg->isd, status);
		return IRQ_HANDLED;
	}
	FLUSH_PCI_READ();
	FLUSH_MEM_READ();

	status = pci_read_32((u_int32_t *) &ci->reg->isd);
	nextInt = INTRPTS_NEXTINT(status);
	intCnt = INTRPTS_INTCNT(status);
	ci->intlog.drvr_intr_thcount++;

	/*********************************************************/
	/* HW Bug Fix                                            */
	/* ----------                                            */
	/* Under certain PCI Bus loading conditions, the         */
	/* MUSYCC looses the data associated with an update      */
	/* of its ISD and erroneously returns the immediately    */
	/* preceding 'nextInt' value.  However, the 'intCnt'     */
	/* value appears to be correct.  By not starting service */
	/* where the 'missing' 'nextInt' SHOULD point causes     */
	/* the IQD not to be serviced - the 'not serviced'       */
	/* entries then remain and continue to increase as more  */
	/* incorrect ISD's are encountered.                      */
	/*********************************************************/

	if (nextInt != INTRPTS_NEXTINT(ci->intlog.this_status_new)) {
		if (cxt1e1_log_level >= LOG_MONITOR) {
			pr_info("%s: note - updated ISD from %08x to %08x\n",
				ci->devname, status,
				(status & (~INTRPTS_NEXTINT_M)) |
				ci->intlog.this_status_new);
		}
		/*
		 * Replace bogus status with software corrected value.
		 *
		 * It's not known whether, during this problem occurrence, if the
		 * INTFULL bit is correctly reported or not.
		 */
		status = (status & (~INTRPTS_NEXTINT_M)) |
			 (ci->intlog.this_status_new);
		nextInt = INTRPTS_NEXTINT(status);
	}
	/**********************************************/
	/* Cn847x Bug Fix                             */
	/* --------------                             */
	/* Fix for inability to write back same index */
	/* as read for a full interrupt queue.        */
	/**********************************************/

	if (intCnt == INT_QUEUE_SIZE)
		currInt = ((intCnt - 1) + nextInt) & (INT_QUEUE_SIZE - 1);
	else
		/************************************************/
		/* Interrupt Write Location Issues              */
		/* -------------------------------              */
		/* When the interrupt status descriptor is      */
		/* written, the interrupt line is de-asserted   */
		/* by the Cn847x.  In the case of MIPS          */
		/* microprocessors, this must occur at the      */
		/* beginning of the interrupt handler so that   */
		/* the interrupt handle is not re-entered due   */
		/* to interrupt dis-assertion latency.          */
		/* In the case of all other processors, this    */
		/* action should occur at the end of the        */
		/* interrupt handler to avoid overwriting the   */
		/* interrupt queue.                             */
		/************************************************/

		if (intCnt)
			currInt = (intCnt + nextInt) & (INT_QUEUE_SIZE - 1);
		else {
			/*
			 * NOTE: Servicing an interrupt whose ISD contains a count of ZERO
			 * can be indicative of a Shared Interrupt chain.  Our driver can be
			 * called from the system's interrupt handler as a matter of the OS
			 * walking the chain.  As the chain is walked, the interrupt will
			 * eventually be serviced by the correct driver/handler.
			 */
			return IRQ_NONE;
		}

	ci->iqp_tailx = currInt;

	currInt <<= INTRPTS_NEXTINT_S;
	ci->intlog.last_status_new = ci->intlog.this_status_new;
	ci->intlog.this_status_new = currInt;

	if ((cxt1e1_log_level >= LOG_WARN) && (status & INTRPTS_INTFULL_M))
		pr_info("%s: Interrupt queue full condition occurred\n",
			ci->devname);
	if (cxt1e1_log_level >= LOG_DEBUG)
		pr_info("%s: interrupts pending, isd @ 0x%p: %x curr %d cnt %d NEXT %d\n",
			ci->devname, &ci->reg->isd,
			status, nextInt, intCnt,
			(intCnt + nextInt) & (INT_QUEUE_SIZE - 1));

	FLUSH_MEM_WRITE();
#if defined(SBE_ISR_TASKLET)
	pci_write_32((u_int32_t *) &ci->reg->isd, currInt);
	atomic_inc(&ci->bh_pending);
	tasklet_schedule(&ci->ci_musycc_isr_tasklet);
#elif defined(SBE_ISR_IMMEDIATE)
	pci_write_32((u_int32_t *) &ci->reg->isd, currInt);
	atomic_inc(&ci->bh_pending);
	queue_task(&ci->ci_musycc_isr_tq, &tq_immediate);
	mark_bh(IMMEDIATE_BH);
#elif defined(SBE_ISR_INLINE)
	(void) musycc_intr_bh_tasklet(ci);
	pci_write_32((u_int32_t *) &ci->reg->isd, currInt);
#endif
	return IRQ_HANDLED;
}


#if defined(SBE_ISR_IMMEDIATE)
unsigned long
#else
void
#endif
musycc_intr_bh_tasklet(ci_t *ci)
{
	mpi_t      *pi;
	mch_t      *ch;
	unsigned int intCnt;
	volatile u_int32_t currInt = 0;
	volatile unsigned int headx, tailx;
	int         readCount, loopCount;
	int         group, gchan, event, err, tx;
	u_int32_t   badInt = INT_EMPTY_ENTRY;
	u_int32_t   badInt2 = INT_EMPTY_ENTRY2;

	/*
	 * Hardware not available, potential interrupt hang.  But since interrupt
	 * might be shared, just return.
	 */
	if ((drvr_state != SBE_DRVR_AVAILABLE) || (ci->state == C_INIT)) {
#if defined(SBE_ISR_IMMEDIATE)
		return 0L;
#else
		return;
#endif
	}
#if defined(SBE_ISR_TASKLET) || defined(SBE_ISR_IMMEDIATE)
	if (drvr_state != SBE_DRVR_AVAILABLE) {
#if defined(SBE_ISR_TASKLET)
		return;
#elif defined(SBE_ISR_IMMEDIATE)
		return 0L;
#endif
	}
#elif defined(SBE_ISR_INLINE)
	/* no semaphore taken, no double checks */
#endif

	ci->intlog.drvr_intr_bhcount++;
	FLUSH_MEM_READ();
	{
		unsigned int bh = atomic_read(&ci->bh_pending);

		max_bh = max(bh, max_bh);
	}
	atomic_set(&ci->bh_pending, 0);/* if here, no longer pending */
	while ((headx = ci->iqp_headx) != (tailx = ci->iqp_tailx)) {
		intCnt = (tailx >= headx) ? (tailx - headx) : (tailx - headx + INT_QUEUE_SIZE);
		currInt = le32_to_cpu(ci->iqd_p[headx]);

		max_intcnt = max(intCnt, max_intcnt);  /* RLD DEBUG */

		/**************************************************/
		/* HW Bug Fix                                     */
		/* ----------                                     */
		/* The following code checks for the condition    */
		/* of interrupt assertion before interrupt        */
		/* queue update.  This is a problem on several    */
		/* PCI-Local bridge chips found on some products. */
		/**************************************************/

		readCount = 0;
		if ((currInt == badInt) || (currInt == badInt2))
			ci->intlog.drvr_int_failure++;

		while ((currInt == badInt) || (currInt == badInt2)) {
			for (loopCount = 0; loopCount < 0x30; loopCount++)
				/* use call to avoid optimization
				 * removal of dummy delay
				 */
				OS_uwait_dummy();
			FLUSH_MEM_READ();
			currInt = le32_to_cpu(ci->iqd_p[headx]);
			if (readCount++ > 20)
				break;
		}

		/* catch failure of Bug Fix checking */
		if ((currInt == badInt) || (currInt == badInt2)) {
			if (cxt1e1_log_level >= LOG_WARN)
				pr_info("%s: Illegal Interrupt Detected @ 0x%p, mod %d.)\n",
					ci->devname, &ci->iqd_p[headx], headx);

			/*
			 * If the descriptor has not recovered, then leaving the EMPTY
			 * entry set will not signal to the MUSYCC that this descriptor
			 * has been serviced. The Interrupt Queue can then start losing
			 * available descriptors and MUSYCC eventually encounters and
			 * reports the INTFULL condition.  Per manual, changing any bit
			 * marks descriptor as available, thus the use of different
			 * EMPTY_ENTRY values.
			 */

			if (currInt == badInt)
				ci->iqd_p[headx] = __constant_cpu_to_le32(INT_EMPTY_ENTRY2);
			else
				ci->iqd_p[headx] = __constant_cpu_to_le32(INT_EMPTY_ENTRY);
			/* insure wrapness */
			ci->iqp_headx = (headx + 1) & (INT_QUEUE_SIZE - 1);
			FLUSH_MEM_WRITE();
			FLUSH_MEM_READ();
			continue;
		}
		group = INTRPT_GRP(currInt);
		gchan = INTRPT_CH(currInt);
		event = INTRPT_EVENT(currInt);
		err = INTRPT_ERROR(currInt);
		tx = currInt & INTRPT_DIR_M;

		ci->iqd_p[headx] = __constant_cpu_to_le32(INT_EMPTY_ENTRY);
		FLUSH_MEM_WRITE();

		if (cxt1e1_log_level >= LOG_DEBUG) {
			if (err != 0)
				pr_info(" %08x -> err: %2d,", currInt, err);

			pr_info("+ interrupt event: %d, grp: %d, chan: %2d, side: %cX\n",
				event, group, gchan, tx ? 'T' : 'R');
		}
		/* notice that here we assume 1-1 group - port mapping */
		pi = &ci->port[group];
		ch = pi->chan[gchan];
		switch (event) {
		case EVE_SACK:              /* Service Request Acknowledge */
			if (cxt1e1_log_level >= LOG_DEBUG) {
				volatile u_int32_t r;

				r = pci_read_32((u_int32_t *) &pi->reg->srd);
				pr_info("- SACK cmd: %08x (hdw= %08x)\n",
					pi->sr_last, r);
			}
			/* wake up waiting process */
			SD_SEM_GIVE(&pi->sr_sem_wait);
			break;
		case EVE_CHABT: /* Change To Abort Code (0x7e -> 0xff) */
		case EVE_CHIC:  /* Change To Idle Code (0xff -> 0x7e) */
			break;
		case EVE_EOM:   /* End Of Message */
		case EVE_EOB:   /* End Of Buffer (Transparent mode) */
			if (tx)
				musycc_bh_tx_eom(pi, gchan);
			else
				musycc_bh_rx_eom(pi, gchan);
			/*
			 * MUSYCC Interrupt Descriptor section states that EOB and EOM
			 * can be combined with the NONE error (as well as others).  So
			 * drop thru to catch this...
			 */
		case EVE_NONE:
			if (err == ERR_SHT)
				ch->s.rx_length_errors++;
			break;
		default:
			if (cxt1e1_log_level >= LOG_WARN)
				pr_info("%s: unexpected interrupt event: %d, iqd[%d]: %08x, port: %d\n", ci->devname,
					event, headx, currInt, group);
			break;
		}                           /* switch on event */


		/*
		 * Per MUSYCC Manual, Section 6.4.8.3 [Transmit Errors], TX errors
		 * are service-affecting and require action to resume normal
		 * bit-level processing.
		 */

		switch (err) {
		case ERR_ONR:
			/*
			 * Per MUSYCC manual, Section  6.4.8.3 [Transmit Errors], this
			 * error requires Transmit channel reactivation.
			 *
			 * Per MUSYCC manual, Section  6.4.8.4 [Receive Errors], this error
			 * requires Receive channel reactivation.
			 */
			if (tx) {

				/*
				 * TX ONR Error only occurs when channel is configured for
				 * Transparent Mode.  However, this code will catch and
				 * re-activate on ANY TX ONR error.
				 */

				/*
				 * Set flag to re-enable on any next transmit attempt.
				 */
				ch->ch_start_tx = CH_START_TX_ONR;

#ifdef RLD_TRANS_DEBUG
				if (1 || cxt1e1_log_level >= LOG_MONITOR)
#else
				if (cxt1e1_log_level >= LOG_MONITOR)
#endif
				{
					pr_info("%s: TX buffer underflow [ONR] on channel %d, mode %x QStopped %x free %d\n",
						ci->devname, ch->channum,
						ch->p.chan_mode,
						sd_queue_stopped(ch->user),
						ch->txd_free);
#ifdef RLD_DEBUG
					/* problem = ONR on HDLC mode */
					if (ch->p.chan_mode == 2) {
						pr_info("++ Failed Last %x Next %x QStopped %x, start_tx %x tx_full %d txd_free %d mode %x\n",
							(u_int32_t)ch->txd_irq_srv,
							(u_int32_t)ch->txd_usr_add,
							sd_queue_stopped(ch->user),
							ch->ch_start_tx,
							ch->tx_full,
							ch->txd_free,
							ch->p.chan_mode);
						musycc_dump_txbuffer_ring(ch, 0);
					}
#endif
				}
			} else {                 /* RX buffer overrun */
				/*
				 * Per MUSYCC manual, Section 6.4.8.4 [Receive Errors],
				 * channel recovery for this RX ONR error IS required.  It is
				 * also suggested to increase the number of receive buffers
				 * for this channel.  Receive channel reactivation IS
				 * required, and data has been lost.
				 */
				ch->s.rx_over_errors++;
				ch->ch_start_rx = CH_START_RX_ONR;

				if (cxt1e1_log_level >= LOG_WARN) {
					pr_info("%s: RX buffer overflow [ONR] on channel %d, mode %x\n",
						ci->devname, ch->channum,
						ch->p.chan_mode);
#ifdef RLD_DEBUG
					musycc_dump_rxbuffer_ring(ch, 0);
#endif
				}
			}
			musycc_chan_restart(ch);
			break;
		case ERR_BUF:
			if (tx) {
				ch->s.tx_fifo_errors++;
				ch->ch_start_tx = CH_START_TX_BUF;
				/*
				 * Per MUSYCC manual, Section  6.4.8.3 [Transmit Errors],
				 * this BUFF error requires Transmit channel reactivation.
				 */
				if (cxt1e1_log_level >= LOG_MONITOR)
					pr_info("%s: TX buffer underrun [BUFF] on channel %d, mode %x\n",
						ci->devname, ch->channum,
						ch->p.chan_mode);
			} else {                 /* RX buffer overrun */
				ch->s.rx_over_errors++;
				/*
				 * Per MUSYCC manual, Section 6.4.8.4 [Receive Errors], HDLC
				 * mode requires NO recovery for this RX BUFF error is
				 * required.  It is suggested to increase the FIFO buffer
				 * space for this channel.  Receive channel reactivation is
				 * not required, but data has been lost.
				 */
				if (cxt1e1_log_level >= LOG_WARN)
					pr_info("%s: RX buffer overrun [BUFF] on channel %d, mode %x\n",
						ci->devname, ch->channum,
						ch->p.chan_mode);
				/*
				 * Per MUSYCC manual, Section 6.4.9.4 [Receive Errors],
				 * Transparent mode DOES require recovery for the RX BUFF
				 * error.  It is suggested to increase the FIFO buffer space
				 * for this channel.  Receive channel reactivation IS
				 * required and data has been lost.
				 */
				if (ch->p.chan_mode == CFG_CH_PROTO_TRANS)
					ch->ch_start_rx = CH_START_RX_BUF;
			}

			if (tx || (ch->p.chan_mode == CFG_CH_PROTO_TRANS))
				musycc_chan_restart(ch);
			break;
		default:
			break;
		}                           /* switch on err */

		/* Check for interrupt lost condition */
		if ((currInt & INTRPT_ILOST_M) &&
		    (cxt1e1_log_level >= LOG_ERROR))
			pr_info("%s: Interrupt queue overflow - ILOST asserted\n",
				ci->devname);
		/* insure wrapness */
		ci->iqp_headx = (headx + 1) & (INT_QUEUE_SIZE - 1);
		FLUSH_MEM_WRITE();
		FLUSH_MEM_READ();
	}                               /* while */
	if ((cxt1e1_log_level >= LOG_MONITOR2) &&
	    (ci->iqp_headx != ci->iqp_tailx)) {
		int         bh;

		bh = atomic_read(&CI->bh_pending);
		pr_info("_bh_: late arrivals, head %d != tail %d, pending %d\n",
			ci->iqp_headx, ci->iqp_tailx, bh);
	}
#if defined(SBE_ISR_IMMEDIATE)
	return 0L;
#endif
	/* else, nothing returned */
}

#ifdef SBE_PMCC4_ENABLE
	status_t
musycc_chan_down(ci_t *dummy, int channum)
{
	mpi_t      *pi;
	mch_t      *ch;
	int         i, gchan;

	ch = sd_find_chan(dummy, channum);
	if (!ch)
		return -EINVAL;
	pi = ch->up;
	gchan = ch->gchan;

	/* Deactivate the channel */
	musycc_serv_req(pi, SR_CHANNEL_DEACTIVATE | SR_RX_DIRECTION | gchan);
	ch->ch_start_rx = 0;
	musycc_serv_req(pi, SR_CHANNEL_DEACTIVATE | SR_TX_DIRECTION | gchan);
	ch->ch_start_tx = 0;

	if (ch->state == DOWN)
		return 0;
	ch->state = DOWN;

	pi->regram->thp[gchan] = 0;
	pi->regram->tmp[gchan] = 0;
	pi->regram->rhp[gchan] = 0;
	pi->regram->rmp[gchan] = 0;
	FLUSH_MEM_WRITE();
	for (i = 0; i < ch->txd_num; i++)
		if (ch->mdt[i].mem_token)
			OS_mem_token_free(ch->mdt[i].mem_token);

	for (i = 0; i < ch->rxd_num; i++)
		if (ch->mdr[i].mem_token)
			OS_mem_token_free(ch->mdr[i].mem_token);

	kfree(ch->mdr);
	ch->mdr = NULL;
	ch->rxd_num = 0;
	kfree(ch->mdt);
	ch->mdt = NULL;
	ch->txd_num = 0;

	musycc_update_timeslots(pi);
	c4_fifo_free(pi, ch->gchan);

	pi->openchans--;
	return 0;
}
#endif

int
musycc_start_xmit(ci_t *ci, int channum, void *mem_token)
{
	mch_t      *ch;
	struct mdesc *md;
	void       *m2;
	int         txd_need_cnt;
	u_int32_t   len;

	ch = sd_find_chan(ci, channum);
	if (!ch)
		return -ENOENT;

	/* full interrupt processing available */
	if (ci->state != C_RUNNING)
		return -EINVAL;
	if (ch->state != UP)
		return -EINVAL;

	/* how else to flag unwritable state ? */
	if (!(ch->status & TX_ENABLED))
		return -EROFS;

#ifdef RLD_TRANS_DEBUG
	if (1 || cxt1e1_log_level >= LOG_MONITOR2)
#else
	if (cxt1e1_log_level >= LOG_MONITOR2)
#endif
	{
		pr_info("++ start_xmt[%d]: state %x start %x full %d free %d required %d stopped %x\n",
			channum, ch->state, ch->ch_start_tx, ch->tx_full,
			ch->txd_free, ch->txd_required,
			sd_queue_stopped(ch->user));
	}
	/***********************************************/
	/** Determine total amount of data to be sent **/
	/***********************************************/
	m2 = mem_token;
	txd_need_cnt = 0;
	for (len = OS_mem_token_tlen(m2); len > 0;
	     m2 = (void *) OS_mem_token_next(m2)) {
		if (!OS_mem_token_len(m2))
			continue;
		txd_need_cnt++;
		len -= OS_mem_token_len(m2);
	}

	if (txd_need_cnt == 0) {
		if (cxt1e1_log_level >= LOG_MONITOR2)
			pr_info("%s channel %d: no TX data in User buffer\n",
				ci->devname, channum);
		OS_mem_token_free(mem_token);
		return 0;                   /* no data to send */
	}
	/*************************************************/
	/** Are there sufficient descriptors available? **/
	/*************************************************/
	if (txd_need_cnt > ch->txd_num) { /* never enough descriptors for this
					   * large a buffer */
		if (cxt1e1_log_level >= LOG_DEBUG)
			pr_info("start_xmit: discarding buffer, insufficient descriptor cnt %d, need %d.\n",
				ch->txd_num, txd_need_cnt + 1);
		ch->s.tx_dropped++;
		OS_mem_token_free(mem_token);
		return 0;
	}

	/************************************************************/
	/** flow control the line if not enough descriptors remain **/
	/************************************************************/
	if (txd_need_cnt > ch->txd_free) {
		if (cxt1e1_log_level >= LOG_MONITOR2)
			pr_info("start_xmit[%d]: EBUSY - need more descriptors, have %d of %d need %d\n",
				channum, ch->txd_free,
				ch->txd_num, txd_need_cnt);
		ch->tx_full = 1;
		ch->txd_required = txd_need_cnt;
		sd_disable_xmit(ch->user);
		return -EBUSY;               /* tell user to try again later */
	}
	/**************************************************/
	/** Put the user data into MUSYCC data buffer(s) **/
	/**************************************************/
	m2 = mem_token;
	md = ch->txd_usr_add;           /* get current available descriptor */

	for (len = OS_mem_token_tlen(m2); len > 0; m2 = OS_mem_token_next(m2)) {
		int         u = OS_mem_token_len(m2);

		if (!u)
			continue;
		len -= u;

		/*
		 * Enable following chunks, yet wait to enable the FIRST chunk until
		 * after ALL subsequent chunks are setup.
		 */
		if (md != ch->txd_usr_add)  /* not first chunk */
			/* transfer ownership from HOST to MUSYCC */
			u |= MUSYCC_TX_OWNED;

		if (len)                    /* not last chunk */
			u |= EOBIRQ_ENABLE;
		else if (ch->p.chan_mode == CFG_CH_PROTO_TRANS) {
			/*
			 * Per MUSYCC Ref 6.4.9 for Transparent Mode, the host must
			 * always clear EOMIRQ_ENABLE in every Transmit Buffer Descriptor
			 * (IE. don't set herein).
			 */
			u |= EOBIRQ_ENABLE;
		} else
			u |= EOMIRQ_ENABLE;     /* EOM, last HDLC chunk */


		/* last chunk in hdlc mode */
		u |= (ch->p.idlecode << IDLE_CODE);
		if (ch->p.pad_fill_count) {
			u |= (PADFILL_ENABLE | (ch->p.pad_fill_count << EXTRA_FLAGS));
		}
		/* Fill in mds on last segment, others set ZERO
		 * so that entire token is removed ONLY when ALL
		 * segments have been transmitted.
		 */
		md->mem_token = len ? NULL : mem_token;

		md->data = cpu_to_le32(OS_vtophys(OS_mem_token_data(m2)));
		FLUSH_MEM_WRITE();
		md->status = cpu_to_le32(u);
		--ch->txd_free;
		md = md->snext;
	}
	FLUSH_MEM_WRITE();


	/*
	 * Now transfer ownership of first chunk from HOST to MUSYCC in order to
	 * fire-off this XMIT.
	 */
	ch->txd_usr_add->status |= __constant_cpu_to_le32(MUSYCC_TX_OWNED);
	FLUSH_MEM_WRITE();
	ch->txd_usr_add = md;

	len = OS_mem_token_tlen(mem_token);
	atomic_add(len, &ch->tx_pending);
	atomic_add(len, &ci->tx_pending);
	ch->s.tx_packets++;
	ch->s.tx_bytes += len;
	/*
	 * If an ONR was seen, then channel requires poking to restart
	 * transmission.
	 */
	if (ch->ch_start_tx)
		musycc_chan_restart(ch);
#ifdef SBE_WAN256T3_ENABLE
	wan256t3_led(ci, LED_TX, LEDV_G);
#endif
	return 0;
}


/*** End-of-File ***/