openwrt-xburst/package/broadcom-wl/src/kmod/hnddma.c

/*
 * Generic Broadcom Home Networking Division (HND) DMA module.
 * This supports the following chips: BCM42xx, 44xx, 47xx .
 *
 * Copyright 2006, Broadcom Corporation
 * All Rights Reserved.
 * 
 * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
 * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
 * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
 *
 * $Id: hnddma.c,v 1.11 2006/04/08 07:12:42 honor Exp $
 */

#include <typedefs.h>
#include <bcmdefs.h>
#include <osl.h>
#include "linux_osl.h"
#include <bcmendian.h>
#include <sbconfig.h>
#include <bcmutils.h>
#include <bcmdevs.h>
#include <sbutils.h>

#include "sbhnddma.h"
#include "hnddma.h"

/* debug/trace */
#define	DMA_ERROR(args)
#define	DMA_TRACE(args)

/* default dma message level (if input msg_level pointer is null in dma_attach()) */
static uint dma_msg_level =
	0;

#define	MAXNAMEL	8		/* 8 char names */

#define	DI_INFO(dmah)	(dma_info_t *)dmah

/* dma engine software state */
typedef struct dma_info {
	struct hnddma_pub hnddma;	/* exported structure, don't use hnddma_t,
					 * which could be const
					 */
	uint		*msg_level;	/* message level pointer */
	char		name[MAXNAMEL];	/* callers name for diag msgs */

	void		*osh;		/* os handle */
	sb_t		*sbh;		/* sb handle */

	bool		dma64;		/* dma64 enabled */
	bool		addrext;	/* this dma engine supports DmaExtendedAddrChanges */

	dma32regs_t	*d32txregs;	/* 32 bits dma tx engine registers */
	dma32regs_t	*d32rxregs;	/* 32 bits dma rx engine registers */
	dma64regs_t	*d64txregs;	/* 64 bits dma tx engine registers */
	dma64regs_t	*d64rxregs;	/* 64 bits dma rx engine registers */

	uint32		dma64align;	/* either 8k or 4k depends on number of dd */
	dma32dd_t	*txd32;		/* pointer to dma32 tx descriptor ring */
	dma64dd_t	*txd64;		/* pointer to dma64 tx descriptor ring */
	uint		ntxd;		/* # tx descriptors tunable */
	uint		txin;		/* index of next descriptor to reclaim */
	uint		txout;		/* index of next descriptor to post */
	void		**txp;		/* pointer to parallel array of pointers to packets */
	osldma_t 	*tx_dmah;	/* DMA TX descriptor ring handle */
	osldma_t	**txp_dmah;	/* DMA TX packet data handle */
	ulong		txdpa;		/* physical address of descriptor ring */
	uint		txdalign;	/* #bytes added to alloc'd mem to align txd */
	uint		txdalloc;	/* #bytes allocated for the ring */

	dma32dd_t	*rxd32;		/* pointer to dma32 rx descriptor ring */
	dma64dd_t	*rxd64;		/* pointer to dma64 rx descriptor ring */
	uint		nrxd;		/* # rx descriptors tunable */
	uint		rxin;		/* index of next descriptor to reclaim */
	uint		rxout;		/* index of next descriptor to post */
	void		**rxp;		/* pointer to parallel array of pointers to packets */
	osldma_t 	*rx_dmah;	/* DMA RX descriptor ring handle */
	osldma_t	**rxp_dmah;	/* DMA RX packet data handle */
	ulong		rxdpa;		/* physical address of descriptor ring */
	uint		rxdalign;	/* #bytes added to alloc'd mem to align rxd */
	uint		rxdalloc;	/* #bytes allocated for the ring */

	/* tunables */
	uint		rxbufsize;	/* rx buffer size in bytes,
					   not including the extra headroom
					*/
	uint		nrxpost;	/* # rx buffers to keep posted */
	uint		rxoffset;	/* rxcontrol offset */
	uint		ddoffsetlow;	/* add to get dma address of descriptor ring, low 32 bits */
	uint		ddoffsethigh;	/*   high 32 bits */
	uint		dataoffsetlow;	/* add to get dma address of data buffer, low 32 bits */
	uint		dataoffsethigh;	/*   high 32 bits */
} dma_info_t;

/* descriptor bumping macros */
#define	XXD(x, n)	((x) & ((n) - 1))	/* faster than %, but n must be power of 2 */
#define	TXD(x)		XXD((x), di->ntxd)
#define	RXD(x)		XXD((x), di->nrxd)
#define	NEXTTXD(i)	TXD(i + 1)
#define	PREVTXD(i)	TXD(i - 1)
#define	NEXTRXD(i)	RXD(i + 1)
#define	NTXDACTIVE(h, t)	TXD(t - h)
#define	NRXDACTIVE(h, t)	RXD(t - h)

/* macros to convert between byte offsets and indexes */
#define	B2I(bytes, type)	((bytes) / sizeof(type))
#define	I2B(index, type)	((index) * sizeof(type))

#define	PCI32ADDR_HIGH		0xc0000000	/* address[31:30] */
#define	PCI32ADDR_HIGH_SHIFT	30		/* address[31:30] */


/* common prototypes */
static bool _dma_isaddrext(dma_info_t *di);
static bool dma32_alloc(dma_info_t *di, uint direction);
static void _dma_detach(dma_info_t *di);
static void _dma_ddtable_init(dma_info_t *di, uint direction, ulong pa);
static void _dma_rxinit(dma_info_t *di);
static void *_dma_rx(dma_info_t *di);
static void _dma_rxfill(dma_info_t *di);
static void _dma_rxreclaim(dma_info_t *di);
static void _dma_rxenable(dma_info_t *di);
static void * _dma_getnextrxp(dma_info_t *di, bool forceall);

static void _dma_txblock(dma_info_t *di);
static void _dma_txunblock(dma_info_t *di);
static uint _dma_txactive(dma_info_t *di);

static void* _dma_peeknexttxp(dma_info_t *di);
static uintptr _dma_getvar(dma_info_t *di, char *name);
static void _dma_counterreset(dma_info_t *di);
static void _dma_fifoloopbackenable(dma_info_t *di);

/* ** 32 bit DMA prototypes */
static bool dma32_alloc(dma_info_t *di, uint direction);
static bool dma32_txreset(dma_info_t *di);
static bool dma32_rxreset(dma_info_t *di);
static bool dma32_txsuspendedidle(dma_info_t *di);
static int  dma32_txfast(dma_info_t *di, void *p0, bool commit);
static void *dma32_getnexttxp(dma_info_t *di, bool forceall);
static void *dma32_getnextrxp(dma_info_t *di, bool forceall);
static void dma32_txrotate(dma_info_t *di);
static bool dma32_rxidle(dma_info_t *di);
static void dma32_txinit(dma_info_t *di);
static bool dma32_txenabled(dma_info_t *di);
static void dma32_txsuspend(dma_info_t *di);
static void dma32_txresume(dma_info_t *di);
static bool dma32_txsuspended(dma_info_t *di);
static void dma32_txreclaim(dma_info_t *di, bool forceall);
static bool dma32_txstopped(dma_info_t *di);
static bool dma32_rxstopped(dma_info_t *di);
static bool dma32_rxenabled(dma_info_t *di);
static bool _dma32_addrext(osl_t *osh, dma32regs_t *dma32regs);


static di_fcn_t dma32proc = {
	(di_detach_t)_dma_detach,
	(di_txinit_t)dma32_txinit,
	(di_txreset_t)dma32_txreset,
	(di_txenabled_t)dma32_txenabled,
	(di_txsuspend_t)dma32_txsuspend,
	(di_txresume_t)dma32_txresume,
	(di_txsuspended_t)dma32_txsuspended,
	(di_txsuspendedidle_t)dma32_txsuspendedidle,
	(di_txfast_t)dma32_txfast,
	(di_txstopped_t)dma32_txstopped,
	(di_txreclaim_t)dma32_txreclaim,
	(di_getnexttxp_t)dma32_getnexttxp,
	(di_peeknexttxp_t)_dma_peeknexttxp,
	(di_txblock_t)_dma_txblock,
	(di_txunblock_t)_dma_txunblock,
	(di_txactive_t)_dma_txactive,
	(di_txrotate_t)dma32_txrotate,

	(di_rxinit_t)_dma_rxinit,
	(di_rxreset_t)dma32_rxreset,
	(di_rxidle_t)dma32_rxidle,
	(di_rxstopped_t)dma32_rxstopped,
	(di_rxenable_t)_dma_rxenable,
	(di_rxenabled_t)dma32_rxenabled,
	(di_rx_t)_dma_rx,
	(di_rxfill_t)_dma_rxfill,
	(di_rxreclaim_t)_dma_rxreclaim,
	(di_getnextrxp_t)_dma_getnextrxp,

	(di_fifoloopbackenable_t)_dma_fifoloopbackenable,
	(di_getvar_t)_dma_getvar,
	(di_counterreset_t)_dma_counterreset,

	NULL,
	NULL,
	NULL,
	34
};

hnddma_t *
dma_attach(osl_t *osh, char *name, sb_t *sbh, void *dmaregstx, void *dmaregsrx,
           uint ntxd, uint nrxd, uint rxbufsize, uint nrxpost, uint rxoffset, uint *msg_level)
{
	dma_info_t *di;
	uint size;

	/* allocate private info structure */
	if ((di = MALLOC(osh, sizeof (dma_info_t))) == NULL) {
		return (NULL);
	}
	bzero((char *)di, sizeof(dma_info_t));

	di->msg_level = msg_level ? msg_level : &dma_msg_level;

	/* old chips w/o sb is no longer supported */
	ASSERT(sbh != NULL);

	/* check arguments */
	ASSERT(ISPOWEROF2(ntxd));
	ASSERT(ISPOWEROF2(nrxd));
	if (nrxd == 0)
		ASSERT(dmaregsrx == NULL);
	if (ntxd == 0)
		ASSERT(dmaregstx == NULL);


	/* init dma reg pointer */
	ASSERT(ntxd <= D32MAXDD);
	ASSERT(nrxd <= D32MAXDD);
	di->d32txregs = (dma32regs_t *)dmaregstx;
	di->d32rxregs = (dma32regs_t *)dmaregsrx;

	DMA_TRACE(("%s: dma_attach: %s osh %p ntxd %d nrxd %d rxbufsize %d nrxpost %d "
	           "rxoffset %d dmaregstx %p dmaregsrx %p\n",
	           name, "DMA32", osh, ntxd, nrxd, rxbufsize,
	           nrxpost, rxoffset, dmaregstx, dmaregsrx));

	/* make a private copy of our callers name */
	strncpy(di->name, name, MAXNAMEL);
	di->name[MAXNAMEL-1] = '\0';

	di->osh = osh;
	di->sbh = sbh;

	/* save tunables */
	di->ntxd = ntxd;
	di->nrxd = nrxd;

	/* the actual dma size doesn't include the extra headroom */
	if (rxbufsize > BCMEXTRAHDROOM)
		di->rxbufsize = rxbufsize - BCMEXTRAHDROOM;
	else
		di->rxbufsize = rxbufsize;

	di->nrxpost = nrxpost;
	di->rxoffset = rxoffset;

	/*
	 * figure out the DMA physical address offset for dd and data
	 *   for old chips w/o sb, use zero
	 *   for new chips w sb,
	 *     PCI/PCIE: they map silicon backplace address to zero based memory, need offset
	 *     Other bus: use zero
	 *     SB_BUS BIGENDIAN kludge: use sdram swapped region for data buffer, not descriptor
	 */
	di->ddoffsetlow = 0;
	di->dataoffsetlow = 0;
	/* for pci bus, add offset */
	if (sbh->bustype == PCI_BUS) {
		di->ddoffsetlow = SB_PCI_DMA;
		di->ddoffsethigh = 0;
		di->dataoffsetlow =  di->ddoffsetlow;
		di->dataoffsethigh =  di->ddoffsethigh;
	}

#if defined(__mips__) && defined(IL_BIGENDIAN)
	di->dataoffsetlow = di->dataoffsetlow + SB_SDRAM_SWAPPED;
#endif

	di->addrext = _dma_isaddrext(di);

	/* allocate tx packet pointer vector */
	if (ntxd) {
		size = ntxd * sizeof(void *);
		if ((di->txp = MALLOC(osh, size)) == NULL) {
			DMA_ERROR(("%s: dma_attach: out of tx memory, malloced %d bytes\n",
			           di->name, MALLOCED(osh)));
			goto fail;
		}
		bzero((char *)di->txp, size);
	}

	/* allocate rx packet pointer vector */
	if (nrxd) {
		size = nrxd * sizeof(void *);
		if ((di->rxp = MALLOC(osh, size)) == NULL) {
			DMA_ERROR(("%s: dma_attach: out of rx memory, malloced %d bytes\n",
			           di->name, MALLOCED(osh)));
			goto fail;
		}
		bzero((char *)di->rxp, size);
	}

	/* allocate transmit descriptor ring, only need ntxd descriptors but it must be aligned */
	if (ntxd) {
		if (!dma32_alloc(di, DMA_TX))
			goto fail;
	}

	/* allocate receive descriptor ring, only need nrxd descriptors but it must be aligned */
	if (nrxd) {
		if (!dma32_alloc(di, DMA_RX))
			goto fail;
	}

	if ((di->ddoffsetlow == SB_PCI_DMA) && (di->txdpa > SB_PCI_DMA_SZ) && !di->addrext) {
		DMA_ERROR(("%s: dma_attach: txdpa 0x%lx: addrext not supported\n",
		           di->name, di->txdpa));
		goto fail;
	}
	if ((di->ddoffsetlow == SB_PCI_DMA) && (di->rxdpa > SB_PCI_DMA_SZ) && !di->addrext) {
		DMA_ERROR(("%s: dma_attach: rxdpa 0x%lx: addrext not supported\n",
		           di->name, di->rxdpa));
		goto fail;
	}

	DMA_TRACE(("ddoffsetlow 0x%x ddoffsethigh 0x%x dataoffsetlow 0x%x dataoffsethigh "
	           "0x%x addrext %d\n", di->ddoffsetlow, di->ddoffsethigh, di->dataoffsetlow,
	           di->dataoffsethigh, di->addrext));

	/* allocate tx packet pointer vector and DMA mapping vectors */
	if (ntxd) {

		size = ntxd * sizeof(osldma_t **);
		if ((di->txp_dmah = (osldma_t **)MALLOC(osh, size)) == NULL)
			goto fail;
		bzero((char*)di->txp_dmah, size);
	}else
		di->txp_dmah = NULL;

	/* allocate rx packet pointer vector and DMA mapping vectors */
	if (nrxd) {

		size = nrxd * sizeof(osldma_t **);
		if ((di->rxp_dmah = (osldma_t **)MALLOC(osh, size)) == NULL)
			goto fail;
		bzero((char*)di->rxp_dmah, size);

	} else
		di->rxp_dmah = NULL;

	/* initialize opsvec of function pointers */
	di->hnddma.di_fn = dma32proc;

	return ((hnddma_t *)di);

fail:
	_dma_detach(di);
	return (NULL);
}

/* init the tx or rx descriptor */
static INLINE void
dma32_dd_upd(dma_info_t *di, dma32dd_t *ddring, ulong pa, uint outidx, uint32 *flags,
             uint32 bufcount)
{
	/* dma32 uses 32 bits control to fit both flags and bufcounter */
	*flags = *flags | (bufcount & CTRL_BC_MASK);

	if ((di->dataoffsetlow != SB_PCI_DMA) || !(pa & PCI32ADDR_HIGH)) {
		W_SM(&ddring[outidx].addr, BUS_SWAP32(pa + di->dataoffsetlow));
		W_SM(&ddring[outidx].ctrl, BUS_SWAP32(*flags));
	} else {
		/* address extension */
		uint32 ae;
		ASSERT(di->addrext);
		ae = (pa & PCI32ADDR_HIGH) >> PCI32ADDR_HIGH_SHIFT;
		pa &= ~PCI32ADDR_HIGH;

		*flags |= (ae << CTRL_AE_SHIFT);
		W_SM(&ddring[outidx].addr, BUS_SWAP32(pa + di->dataoffsetlow));
		W_SM(&ddring[outidx].ctrl, BUS_SWAP32(*flags));
	}
}

static bool
_dma32_addrext(osl_t *osh, dma32regs_t *dma32regs)
{
	uint32 w;

	OR_REG(osh, &dma32regs->control, XC_AE);
	w = R_REG(osh, &dma32regs->control);
	AND_REG(osh, &dma32regs->control, ~XC_AE);
	return ((w & XC_AE) == XC_AE);
}

/* !! may be called with core in reset */
static void
_dma_detach(dma_info_t *di)
{
	if (di == NULL)
		return;

	DMA_TRACE(("%s: dma_detach\n", di->name));

	/* shouldn't be here if descriptors are unreclaimed */
	ASSERT(di->txin == di->txout);
	ASSERT(di->rxin == di->rxout);

	/* free dma descriptor rings */
	if (di->txd32)
		DMA_FREE_CONSISTENT(di->osh, ((int8*)di->txd32 - di->txdalign),
		                    di->txdalloc, (di->txdpa - di->txdalign), &di->tx_dmah);
	if (di->rxd32)
		DMA_FREE_CONSISTENT(di->osh, ((int8*)di->rxd32 - di->rxdalign),
		                    di->rxdalloc, (di->rxdpa - di->rxdalign), &di->rx_dmah);

	/* free packet pointer vectors */
	if (di->txp)
		MFREE(di->osh, (void *)di->txp, (di->ntxd * sizeof(void *)));
	if (di->rxp)
		MFREE(di->osh, (void *)di->rxp, (di->nrxd * sizeof(void *)));

	/* free tx packet DMA handles */
	if (di->txp_dmah)
		MFREE(di->osh, (void *)di->txp_dmah, di->ntxd * sizeof(osldma_t **));

	/* free rx packet DMA handles */
	if (di->rxp_dmah)
		MFREE(di->osh, (void *)di->rxp_dmah, di->nrxd * sizeof(osldma_t **));

	/* free our private info structure */
	MFREE(di->osh, (void *)di, sizeof(dma_info_t));

}

/* return TRUE if this dma engine supports DmaExtendedAddrChanges, otherwise FALSE */
static bool
_dma_isaddrext(dma_info_t *di)
{
	if (di->d32txregs)
		return (_dma32_addrext(di->osh, di->d32txregs));
	else if (di->d32rxregs)
		return (_dma32_addrext(di->osh, di->d32rxregs));
	return FALSE;
}

/* initialize descriptor table base address */
static void
_dma_ddtable_init(dma_info_t *di, uint direction, ulong pa)
{
	if ((di->ddoffsetlow != SB_PCI_DMA) || !(pa & PCI32ADDR_HIGH)) {
		if (direction == DMA_TX)
			W_REG(di->osh, &di->d32txregs->addr, (pa + di->ddoffsetlow));
		else
			W_REG(di->osh, &di->d32rxregs->addr, (pa + di->ddoffsetlow));
	} else {
		/* dma32 address extension */
		uint32 ae;
		ASSERT(di->addrext);

		/* shift the high bit(s) from pa to ae */
		ae = (pa & PCI32ADDR_HIGH) >> PCI32ADDR_HIGH_SHIFT;
		pa &= ~PCI32ADDR_HIGH;

		if (direction == DMA_TX) {
			W_REG(di->osh, &di->d32txregs->addr, (pa + di->ddoffsetlow));
			SET_REG(di->osh, &di->d32txregs->control, XC_AE, ae <<XC_AE_SHIFT);
		} else {
			W_REG(di->osh, &di->d32rxregs->addr, (pa + di->ddoffsetlow));
			SET_REG(di->osh, &di->d32rxregs->control, RC_AE, ae <<RC_AE_SHIFT);
		}
	}
}

static void
_dma_fifoloopbackenable(dma_info_t *di)
{
	DMA_TRACE(("%s: dma_fifoloopbackenable\n", di->name));
	OR_REG(di->osh, &di->d32txregs->control, XC_LE);
}

static void
_dma_rxinit(dma_info_t *di)
{
	DMA_TRACE(("%s: dma_rxinit\n", di->name));

	if (di->nrxd == 0)
		return;

	di->rxin = di->rxout = 0;

	/* clear rx descriptor ring */
	BZERO_SM((void *)di->rxd32, (di->nrxd * sizeof(dma32dd_t)));
	_dma_rxenable(di);
	_dma_ddtable_init(di, DMA_RX, di->rxdpa);
}

static void
_dma_rxenable(dma_info_t *di)
{
	DMA_TRACE(("%s: dma_rxenable\n", di->name));

	W_REG(di->osh, &di->d32rxregs->control, ((di->rxoffset << RC_RO_SHIFT) | RC_RE));
}

/* !! rx entry routine, returns a pointer to the next frame received,
 * or NULL if there are no more
 */
static void *
_dma_rx(dma_info_t *di)
{
	void *p;
	uint len;
	int skiplen = 0;

	while ((p = _dma_getnextrxp(di, FALSE))) {
		/* skip giant packets which span multiple rx descriptors */
		if (skiplen > 0) {
			skiplen -= di->rxbufsize;
			if (skiplen < 0)
				skiplen = 0;
			PKTFREE(di->osh, p, FALSE);
			continue;
		}

		len = ltoh16(*(uint16*)(PKTDATA(di->osh, p)));
		DMA_TRACE(("%s: dma_rx len %d\n", di->name, len));

		/* bad frame length check */
		if (len > (di->rxbufsize - di->rxoffset)) {
			DMA_ERROR(("%s: dma_rx: bad frame length (%d)\n", di->name, len));
			if (len > 0)
				skiplen = len - (di->rxbufsize - di->rxoffset);
			PKTFREE(di->osh, p, FALSE);
			di->hnddma.rxgiants++;
			continue;
		}

		/* set actual length */
		PKTSETLEN(di->osh, p, (di->rxoffset + len));

		break;
	}

	return (p);
}

/* post receive buffers */
static void
_dma_rxfill(dma_info_t *di)
{
	void *p;
	uint rxin, rxout;
	uint32 flags = 0;
	uint n;
	uint i;
	uint32 pa;
	uint extra_offset = 0;

	/*
	 * Determine how many receive buffers we're lacking
	 * from the full complement, allocate, initialize,
	 * and post them, then update the chip rx lastdscr.
	 */

	rxin = di->rxin;
	rxout = di->rxout;

	n = di->nrxpost - NRXDACTIVE(rxin, rxout);

	DMA_TRACE(("%s: dma_rxfill: post %d\n", di->name, n));

	if (di->rxbufsize > BCMEXTRAHDROOM)
		extra_offset = BCMEXTRAHDROOM;

	for (i = 0; i < n; i++) {
		/* the di->rxbufsize doesn't include the extra headroom, we need to add it to the
		   size to be allocated
		*/
		if ((p = PKTGET(di->osh, di->rxbufsize + extra_offset,
		                FALSE)) == NULL) {
			DMA_ERROR(("%s: dma_rxfill: out of rxbufs\n", di->name));
			di->hnddma.rxnobuf++;
			break;
		}
		/* reserve an extra headroom, if applicable */
		if (extra_offset)
			PKTPULL(di->osh, p, extra_offset);

		/* Do a cached write instead of uncached write since DMA_MAP
		 * will flush the cache.
		 */
		*(uint32*)(PKTDATA(di->osh, p)) = 0;

		pa = (uint32) DMA_MAP(di->osh, PKTDATA(di->osh, p),
		                      di->rxbufsize, DMA_RX, p);

		ASSERT(ISALIGNED(pa, 4));

		/* save the free packet pointer */
		ASSERT(di->rxp[rxout] == NULL);
		di->rxp[rxout] = p;

		/* reset flags for each descriptor */
		flags = 0;
		if (rxout == (di->nrxd - 1))
			flags = CTRL_EOT;
		dma32_dd_upd(di, di->rxd32, pa, rxout, &flags, di->rxbufsize);
		rxout = NEXTRXD(rxout);
	}

	di->rxout = rxout;

	/* update the chip lastdscr pointer */
	W_REG(di->osh, &di->d32rxregs->ptr, I2B(rxout, dma32dd_t));
}

/* like getnexttxp but no reclaim */
static void *
_dma_peeknexttxp(dma_info_t *di)
{
	uint end, i;

	if (di->ntxd == 0)
		return (NULL);

	end = B2I(R_REG(di->osh, &di->d32txregs->status) & XS_CD_MASK, dma32dd_t);

	for (i = di->txin; i != end; i = NEXTTXD(i))
		if (di->txp[i])
			return (di->txp[i]);

	return (NULL);
}

static void
_dma_rxreclaim(dma_info_t *di)
{
	void *p;

	/* "unused local" warning suppression for OSLs that
	 * define PKTFREE() without using the di->osh arg
	 */
	di = di;

	DMA_TRACE(("%s: dma_rxreclaim\n", di->name));

	while ((p = _dma_getnextrxp(di, TRUE)))
		PKTFREE(di->osh, p, FALSE);
}

static void *
_dma_getnextrxp(dma_info_t *di, bool forceall)
{
	if (di->nrxd == 0)
		return (NULL);

	return dma32_getnextrxp(di, forceall);
}

static void
_dma_txblock(dma_info_t *di)
{
	di->hnddma.txavail = 0;
}

static void
_dma_txunblock(dma_info_t *di)
{
	di->hnddma.txavail = di->ntxd - NTXDACTIVE(di->txin, di->txout) - 1;
}

static uint
_dma_txactive(dma_info_t *di)
{
	return (NTXDACTIVE(di->txin, di->txout));
}

static void
_dma_counterreset(dma_info_t *di)
{
	/* reset all software counter */
	di->hnddma.rxgiants = 0;
	di->hnddma.rxnobuf = 0;
	di->hnddma.txnobuf = 0;
}

/* get the address of the var in order to change later */
static uintptr
_dma_getvar(dma_info_t *di, char *name)
{
	if (!strcmp(name, "&txavail"))
		return ((uintptr) &(di->hnddma.txavail));
	else {
		ASSERT(0);
	}
	return (0);
}

void
dma_txpioloopback(osl_t *osh, dma32regs_t *regs)
{
	OR_REG(osh, &regs->control, XC_LE);
}



/* 32 bits DMA functions */
static void
dma32_txinit(dma_info_t *di)
{
	DMA_TRACE(("%s: dma_txinit\n", di->name));

	if (di->ntxd == 0)
		return;

	di->txin = di->txout = 0;
	di->hnddma.txavail = di->ntxd - 1;

	/* clear tx descriptor ring */
	BZERO_SM((void *)di->txd32, (di->ntxd * sizeof(dma32dd_t)));
	W_REG(di->osh, &di->d32txregs->control, XC_XE);
	_dma_ddtable_init(di, DMA_TX, di->txdpa);
}

static bool
dma32_txenabled(dma_info_t *di)
{
	uint32 xc;

	/* If the chip is dead, it is not enabled :-) */
	xc = R_REG(di->osh, &di->d32txregs->control);
	return ((xc != 0xffffffff) && (xc & XC_XE));
}

static void
dma32_txsuspend(dma_info_t *di)
{
	DMA_TRACE(("%s: dma_txsuspend\n", di->name));

	if (di->ntxd == 0)
		return;

	OR_REG(di->osh, &di->d32txregs->control, XC_SE);
}

static void
dma32_txresume(dma_info_t *di)
{
	DMA_TRACE(("%s: dma_txresume\n", di->name));

	if (di->ntxd == 0)
		return;

	AND_REG(di->osh, &di->d32txregs->control, ~XC_SE);
}

static bool
dma32_txsuspended(dma_info_t *di)
{
	return (di->ntxd == 0) || ((R_REG(di->osh, &di->d32txregs->control) & XC_SE) == XC_SE);
}

static void
dma32_txreclaim(dma_info_t *di, bool forceall)
{
	void *p;

	DMA_TRACE(("%s: dma_txreclaim %s\n", di->name, forceall ? "all" : ""));

	while ((p = dma32_getnexttxp(di, forceall)))
		PKTFREE(di->osh, p, TRUE);
}

static bool
dma32_txstopped(dma_info_t *di)
{
	return ((R_REG(di->osh, &di->d32txregs->status) & XS_XS_MASK) == XS_XS_STOPPED);
}

static bool
dma32_rxstopped(dma_info_t *di)
{
	return ((R_REG(di->osh, &di->d32rxregs->status) & RS_RS_MASK) == RS_RS_STOPPED);
}

static bool
dma32_alloc(dma_info_t *di, uint direction)
{
	uint size;
	uint ddlen;
	void *va;

	ddlen = sizeof(dma32dd_t);

	size = (direction == DMA_TX) ? (di->ntxd * ddlen) : (di->nrxd * ddlen);

	if (!ISALIGNED(DMA_CONSISTENT_ALIGN, D32RINGALIGN))
		size += D32RINGALIGN;


	if (direction == DMA_TX) {
		if ((va = DMA_ALLOC_CONSISTENT(di->osh, size, &di->txdpa, &di->tx_dmah)) == NULL) {
			DMA_ERROR(("%s: dma_attach: DMA_ALLOC_CONSISTENT(ntxd) failed\n",
			           di->name));
			return FALSE;
		}

		di->txd32 = (dma32dd_t *) ROUNDUP((uintptr)va, D32RINGALIGN);
		di->txdalign = (uint)((int8*)di->txd32 - (int8*)va);
		di->txdpa += di->txdalign;
		di->txdalloc = size;
		ASSERT(ISALIGNED((uintptr)di->txd32, D32RINGALIGN));
	} else {
		if ((va = DMA_ALLOC_CONSISTENT(di->osh, size, &di->rxdpa, &di->rx_dmah)) == NULL) {
			DMA_ERROR(("%s: dma_attach: DMA_ALLOC_CONSISTENT(nrxd) failed\n",
			           di->name));
			return FALSE;
		}
		di->rxd32 = (dma32dd_t *) ROUNDUP((uintptr)va, D32RINGALIGN);
		di->rxdalign = (uint)((int8*)di->rxd32 - (int8*)va);
		di->rxdpa += di->rxdalign;
		di->rxdalloc = size;
		ASSERT(ISALIGNED((uintptr)di->rxd32, D32RINGALIGN));
	}

	return TRUE;
}

static bool
dma32_txreset(dma_info_t *di)
{
	uint32 status;

	if (di->ntxd == 0)
		return TRUE;

	/* suspend tx DMA first */
	W_REG(di->osh, &di->d32txregs->control, XC_SE);
	SPINWAIT(((status = (R_REG(di->osh, &di->d32txregs->status) & XS_XS_MASK))
		 != XS_XS_DISABLED) &&
		 (status != XS_XS_IDLE) &&
		 (status != XS_XS_STOPPED),
		 (10000));

	W_REG(di->osh, &di->d32txregs->control, 0);
	SPINWAIT(((status = (R_REG(di->osh,
	         &di->d32txregs->status) & XS_XS_MASK)) != XS_XS_DISABLED),
	         10000);

	/* wait for the last transaction to complete */
	OSL_DELAY(300);

	return (status == XS_XS_DISABLED);
}

static bool
dma32_rxidle(dma_info_t *di)
{
	DMA_TRACE(("%s: dma_rxidle\n", di->name));

	if (di->nrxd == 0)
		return TRUE;

	return ((R_REG(di->osh, &di->d32rxregs->status) & RS_CD_MASK) ==
	        R_REG(di->osh, &di->d32rxregs->ptr));
}

static bool
dma32_rxreset(dma_info_t *di)
{
	uint32 status;

	if (di->nrxd == 0)
		return TRUE;

	W_REG(di->osh, &di->d32rxregs->control, 0);
	SPINWAIT(((status = (R_REG(di->osh,
	         &di->d32rxregs->status) & RS_RS_MASK)) != RS_RS_DISABLED),
	         10000);

	return (status == RS_RS_DISABLED);
}

static bool
dma32_rxenabled(dma_info_t *di)
{
	uint32 rc;

	rc = R_REG(di->osh, &di->d32rxregs->control);
	return ((rc != 0xffffffff) && (rc & RC_RE));
}

static bool
dma32_txsuspendedidle(dma_info_t *di)
{
	if (di->ntxd == 0)
		return TRUE;

	if (!(R_REG(di->osh, &di->d32txregs->control) & XC_SE))
		return 0;

	if ((R_REG(di->osh, &di->d32txregs->status) & XS_XS_MASK) != XS_XS_IDLE)
		return 0;

	OSL_DELAY(2);
	return ((R_REG(di->osh, &di->d32txregs->status) & XS_XS_MASK) == XS_XS_IDLE);
}

/* !! tx entry routine
 * supports full 32bit dma engine buffer addressing so
 * dma buffers can cross 4 Kbyte page boundaries.
 */
static int
dma32_txfast(dma_info_t *di, void *p0, bool commit)
{
	void *p, *next;
	uchar *data;
	uint len;
	uint txout;
	uint32 flags = 0;
	uint32 pa;

	DMA_TRACE(("%s: dma_txfast\n", di->name));

	txout = di->txout;

	/*
	 * Walk the chain of packet buffers
	 * allocating and initializing transmit descriptor entries.
	 */
	for (p = p0; p; p = next) {
		data = PKTDATA(di->osh, p);
		len = PKTLEN(di->osh, p);
		next = PKTNEXT(di->osh, p);

		/* return nonzero if out of tx descriptors */
		if (NEXTTXD(txout) == di->txin)
			goto outoftxd;

		if (len == 0)
			continue;

		/* get physical address of buffer start */
		pa = (uint32) DMA_MAP(di->osh, data, len, DMA_TX, p);

		flags = 0;
		if (p == p0)
			flags |= CTRL_SOF;
		if (next == NULL)
			flags |= (CTRL_IOC | CTRL_EOF);
		if (txout == (di->ntxd - 1))
			flags |= CTRL_EOT;

		dma32_dd_upd(di, di->txd32, pa, txout, &flags, len);
		ASSERT(di->txp[txout] == NULL);

		txout = NEXTTXD(txout);
	}

	/* if last txd eof not set, fix it */
	if (!(flags & CTRL_EOF))
		W_SM(&di->txd32[PREVTXD(txout)].ctrl, BUS_SWAP32(flags | CTRL_IOC | CTRL_EOF));

	/* save the packet */
	di->txp[PREVTXD(txout)] = p0;

	/* bump the tx descriptor index */
	di->txout = txout;

	/* kick the chip */
	if (commit)
		W_REG(di->osh, &di->d32txregs->ptr, I2B(txout, dma32dd_t));

	/* tx flow control */
	di->hnddma.txavail = di->ntxd - NTXDACTIVE(di->txin, di->txout) - 1;

	return (0);

outoftxd:
	DMA_ERROR(("%s: dma_txfast: out of txds\n", di->name));
	PKTFREE(di->osh, p0, TRUE);
	di->hnddma.txavail = 0;
	di->hnddma.txnobuf++;
	return (-1);
}

/*
 * Reclaim next completed txd (txds if using chained buffers) and
 * return associated packet.
 * If 'force' is true, reclaim txd(s) and return associated packet
 * regardless of the value of the hardware "curr" pointer.
 */
static void *
dma32_getnexttxp(dma_info_t *di, bool forceall)
{
	uint start, end, i;
	void *txp;

	DMA_TRACE(("%s: dma_getnexttxp %s\n", di->name, forceall ? "all" : ""));

	if (di->ntxd == 0)
		return (NULL);

	txp = NULL;

	start = di->txin;
	if (forceall)
		end = di->txout;
	else
		end = B2I(R_REG(di->osh, &di->d32txregs->status) & XS_CD_MASK, dma32dd_t);

	if ((start == 0) && (end > di->txout))
		goto bogus;

	for (i = start; i != end && !txp; i = NEXTTXD(i)) {
		DMA_UNMAP(di->osh, (BUS_SWAP32(R_SM(&di->txd32[i].addr)) - di->dataoffsetlow),
		          (BUS_SWAP32(R_SM(&di->txd32[i].ctrl)) & CTRL_BC_MASK),
		          DMA_TX, di->txp[i]);

		W_SM(&di->txd32[i].addr, 0xdeadbeef);
		txp = di->txp[i];
		di->txp[i] = NULL;
	}

	di->txin = i;

	/* tx flow control */
	di->hnddma.txavail = di->ntxd - NTXDACTIVE(di->txin, di->txout) - 1;

	return (txp);

bogus:
/*
	DMA_ERROR(("dma_getnexttxp: bogus curr: start %d end %d txout %d force %d\n",
		start, end, di->txout, forceall));
*/
	return (NULL);
}

static void *
dma32_getnextrxp(dma_info_t *di, bool forceall)
{
	uint i;
	void *rxp;

	/* if forcing, dma engine must be disabled */
	ASSERT(!forceall || !dma32_rxenabled(di));

	i = di->rxin;

	/* return if no packets posted */
	if (i == di->rxout)
		return (NULL);

	/* ignore curr if forceall */
	if (!forceall && (i == B2I(R_REG(di->osh, &di->d32rxregs->status) & RS_CD_MASK, dma32dd_t)))
		return (NULL);

	/* get the packet pointer that corresponds to the rx descriptor */
	rxp = di->rxp[i];
	ASSERT(rxp);
	di->rxp[i] = NULL;

	/* clear this packet from the descriptor ring */
	DMA_UNMAP(di->osh, (BUS_SWAP32(R_SM(&di->rxd32[i].addr)) - di->dataoffsetlow),
	          di->rxbufsize, DMA_RX, rxp);

	W_SM(&di->rxd32[i].addr, 0xdeadbeef);

	di->rxin = NEXTRXD(i);

	return (rxp);
}

/*
 * Rotate all active tx dma ring entries "forward" by (ActiveDescriptor - txin).
 */
static void
dma32_txrotate(dma_info_t *di)
{
	uint ad;
	uint nactive;
	uint rot;
	uint old, new;
	uint32 w;
	uint first, last;

	ASSERT(dma32_txsuspendedidle(di));

	nactive = _dma_txactive(di);
	ad = B2I(((R_REG(di->osh, &di->d32txregs->status) & XS_AD_MASK) >> XS_AD_SHIFT), dma32dd_t);
	rot = TXD(ad - di->txin);

	ASSERT(rot < di->ntxd);

	/* full-ring case is a lot harder - don't worry about this */
	if (rot >= (di->ntxd - nactive)) {
		DMA_ERROR(("%s: dma_txrotate: ring full - punt\n", di->name));
		return;
	}

	first = di->txin;
	last = PREVTXD(di->txout);

	/* move entries starting at last and moving backwards to first */
	for (old = last; old != PREVTXD(first); old = PREVTXD(old)) {
		new = TXD(old + rot);

		/*
		 * Move the tx dma descriptor.
		 * EOT is set only in the last entry in the ring.
		 */
		w = BUS_SWAP32(R_SM(&di->txd32[old].ctrl)) & ~CTRL_EOT;
		if (new == (di->ntxd - 1))
			w |= CTRL_EOT;
		W_SM(&di->txd32[new].ctrl, BUS_SWAP32(w));
		W_SM(&di->txd32[new].addr, R_SM(&di->txd32[old].addr));

		/* zap the old tx dma descriptor address field */
		W_SM(&di->txd32[old].addr, BUS_SWAP32(0xdeadbeef));

		/* move the corresponding txp[] entry */
		ASSERT(di->txp[new] == NULL);
		di->txp[new] = di->txp[old];
		di->txp[old] = NULL;
	}

	/* update txin and txout */
	di->txin = ad;
	di->txout = TXD(di->txout + rot);
	di->hnddma.txavail = di->ntxd - NTXDACTIVE(di->txin, di->txout) - 1;

	/* kick the chip */
	W_REG(di->osh, &di->d32txregs->ptr, I2B(di->txout, dma32dd_t));
}


uint
dma_addrwidth(sb_t *sbh, void *dmaregs)
{
	dma32regs_t *dma32regs;
	osl_t *osh;

	osh = sb_osh(sbh);

	/* Start checking for 32-bit / 30-bit addressing */
	dma32regs = (dma32regs_t *)dmaregs;

	/* For System Backplane, PCIE bus or addrext feature, 32-bits ok */
	if ((BUSTYPE(sbh->bustype) == SB_BUS) ||
	    ((BUSTYPE(sbh->bustype) == PCI_BUS) && sbh->buscoretype == SB_PCIE) ||
	    (_dma32_addrext(osh, dma32regs)))
		return (DMADDRWIDTH_32);

	/* Fallthru */
	return (DMADDRWIDTH_30);
}