/* $OpenBSD: dma.c,v 1.14 2004/09/29 07:35:52 miod Exp $ */ /* $NetBSD: dma.c,v 1.19 1997/05/05 21:02:39 thorpej Exp $ */ /* * Copyright (c) 1995, 1996, 1997 * Jason R. Thorpe. All rights reserved. * Copyright (c) 1982, 1990, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)dma.c 8.1 (Berkeley) 6/10/93 */ /* * DMA driver */ #include #include #include #include #include #include #include #include #include #include #include #include /* * The largest single request will be MAXPHYS bytes which will require * at most MAXPHYS/NBPG+1 chain elements to describe, i.e. if none of * the buffer pages are physically contiguous (MAXPHYS/NBPG) and the * buffer is not page aligned (+1). */ #define DMAMAXIO (MAXPHYS/NBPG+1) struct dma_chain { int dc_count; char *dc_addr; }; struct dma_channel { struct dmaqueue *dm_job; /* current job */ struct dmadevice *dm_hwaddr; /* registers if DMA_C */ struct dmaBdevice *dm_Bhwaddr; /* registers if not DMA_C */ char dm_flags; /* misc. flags */ u_short dm_cmd; /* DMA controller command */ int dm_cur; /* current segment */ int dm_last; /* last segment */ struct dma_chain dm_chain[DMAMAXIO]; /* all segments */ }; struct dma_softc { struct dmareg *sc_dmareg; /* pointer to our hardware */ struct isr sc_isr; struct dma_channel sc_chan[NDMACHAN]; /* 2 channels */ #ifdef DEBUG struct timeout sc_timeout; /* DMA timeout */ #endif TAILQ_HEAD(, dmaqueue) sc_queue; /* job queue */ char sc_type; /* A, B, or C */ } dma_softc; /* types */ #define DMA_B 0 #define DMA_C 1 /* flags */ #define DMAF_PCFLUSH 0x01 #define DMAF_VCFLUSH 0x02 #define DMAF_NOINTR 0x04 int dmaintr(void *); #ifdef DEBUG int dmadebug = 0; #define DDB_WORD 0x01 /* same as DMAGO_WORD */ #define DDB_LWORD 0x02 /* same as DMAGO_LWORD */ #define DDB_FOLLOW 0x04 #define DDB_IO 0x08 void dmatimeout(void *); int dmatimo[NDMACHAN]; long dmahits[NDMACHAN]; long dmamisses[NDMACHAN]; long dmabyte[NDMACHAN]; long dmaword[NDMACHAN]; long dmalword[NDMACHAN]; #endif /* * Initialize the DMA engine, called by dioattach() */ void dmainit() { struct dma_softc *sc = &dma_softc; struct dmareg *dma; struct dma_channel *dc; int i; char rev; /* There's just one. */ sc->sc_dmareg = (struct dmareg *)DMA_BASE; dma = sc->sc_dmareg; /* * Determine the DMA type. A DMA_A or DMA_B will fail the * following probe. * * XXX Don't know how to easily differentiate the A and B cards, * so we just hope nobody has an A card (A cards will work if * splbio works out to ipl 3). */ if (badbaddr((char *)&dma->dma_id[2])) { rev = 'B'; #if !defined(HP320) panic("dmainit: DMA card requires hp320 support"); #endif } else rev = dma->dma_id[2]; sc->sc_type = (rev == 'B') ? DMA_B : DMA_C; TAILQ_INIT(&sc->sc_queue); for (i = 0; i < NDMACHAN; i++) { dc = &sc->sc_chan[i]; dc->dm_job = NULL; switch (i) { case 0: dc->dm_hwaddr = &dma->dma_chan0; dc->dm_Bhwaddr = &dma->dma_Bchan0; break; case 1: dc->dm_hwaddr = &dma->dma_chan1; dc->dm_Bhwaddr = &dma->dma_Bchan1; break; default: panic("dmainit: more than 2 channels?"); /* NOTREACHED */ } } #ifdef DEBUG /* make sure timeout is really not needed */ timeout_set(&sc->sc_timeout, dmatimeout, sc); timeout_add(&sc->sc_timeout, 30 * hz); #endif printf("98620%c, 2 channels, %d bit DMA\n", rev, (rev == 'B') ? 16 : 32); /* * Our interrupt level must be as high as the highest * device using DMA (i.e. splbio). */ sc->sc_isr.isr_ipl = PSLTOIPL(hp300_bioipl); /* * Defer hooking up our interrupt until the first * DMA-using controller has hooked up theirs. */ sc->sc_isr.isr_func = NULL; sc->sc_isr.isr_arg = sc; sc->sc_isr.isr_priority = IPL_BIO; } /* * Compute the ipl and (re)establish the interrupt handler * for the DMA controller. */ void dmacomputeipl() { struct dma_softc *sc = &dma_softc; if (sc->sc_isr.isr_func != NULL) intr_disestablish(&sc->sc_isr); sc->sc_isr.isr_func = dmaintr; intr_establish(&sc->sc_isr, "dma"); } int dmareq(dq) struct dmaqueue *dq; { struct dma_softc *sc = &dma_softc; int i, chan, s; #if 1 s = splhigh(); /* XXXthorpej */ #else s = splbio(); #endif chan = dq->dq_chan; for (i = NDMACHAN - 1; i >= 0; i--) { /* * Can we use this channel? */ if ((chan & (1 << i)) == 0) continue; /* * We can use it; is it busy? */ if (sc->sc_chan[i].dm_job != NULL) continue; /* * Not busy; give the caller this channel. */ sc->sc_chan[i].dm_job = dq; dq->dq_chan = i; splx(s); return (1); } /* * Couldn't get a channel now; put this in the queue. */ TAILQ_INSERT_TAIL(&sc->sc_queue, dq, dq_list); splx(s); return (0); } void dmafree(dq) struct dmaqueue *dq; { int unit = dq->dq_chan; struct dma_softc *sc = &dma_softc; struct dma_channel *dc = &sc->sc_chan[unit]; struct dmaqueue *dn; int chan, s; #if 1 s = splhigh(); /* XXXthorpej */ #else s = splbio(); #endif #ifdef DEBUG dmatimo[unit] = 0; #endif DMA_CLEAR(dc); #if defined(CACHE_HAVE_PAC) || defined(M68040) /* * XXX we may not always go thru the flush code in dmastop() */ if (dc->dm_flags & DMAF_PCFLUSH) { PCIA(); dc->dm_flags &= ~DMAF_PCFLUSH; } #endif #if defined(CACHE_HAVE_VAC) if (dc->dm_flags & DMAF_VCFLUSH) { /* * 320/350s have VACs that may also need flushing. * In our case we only flush the supervisor side * because we know that if we are DMAing to user * space, the physical pages will also be mapped * in kernel space (via vmapbuf) and hence cache- * inhibited by the pmap module due to the multiple * mapping. */ DCIS(); dc->dm_flags &= ~DMAF_VCFLUSH; } #endif /* * Channel is now free. Look for another job to run on this * channel. */ dc->dm_job = NULL; chan = 1 << unit; for (dn = sc->sc_queue.tqh_first; dn != NULL; dn = dn->dq_list.tqe_next) { if (dn->dq_chan & chan) { /* Found one... */ TAILQ_REMOVE(&sc->sc_queue, dn, dq_list); dc->dm_job = dn; dn->dq_chan = dq->dq_chan; splx(s); /* Start the initiator. */ (*dn->dq_start)(dn->dq_softc); return; } } splx(s); } void dmago(unit, addr, count, flags) int unit; char *addr; int count; int flags; { struct dma_softc *sc = &dma_softc; struct dma_channel *dc = &sc->sc_chan[unit]; char *dmaend = NULL; int seg, tcount; #ifdef DIAGNOSTIC if (count > MAXPHYS) panic("dmago: count > MAXPHYS"); #endif #if defined(HP320) if (sc->sc_type == DMA_B && (flags & DMAGO_LWORD)) panic("dmago: no can do 32-bit DMA"); #endif #ifdef DEBUG if (dmadebug & DDB_FOLLOW) printf("dmago(%d, %p, %x, %x)\n", unit, addr, count, flags); if (flags & DMAGO_LWORD) dmalword[unit]++; else if (flags & DMAGO_WORD) dmaword[unit]++; else dmabyte[unit]++; #endif /* * Build the DMA chain */ for (seg = 0; count > 0; seg++) { dc->dm_chain[seg].dc_addr = (char *) kvtop(addr); #if defined(M68040) /* * Push back dirty cache lines */ if (mmutype == MMU_68040) DCFP((paddr_t)dc->dm_chain[seg].dc_addr); #endif if (count < (tcount = NBPG - ((int)addr & PGOFSET))) tcount = count; dc->dm_chain[seg].dc_count = tcount; addr += tcount; count -= tcount; if (flags & DMAGO_LWORD) tcount >>= 2; else if (flags & DMAGO_WORD) tcount >>= 1; /* * Try to compact the DMA transfer if the pages are adjacent. * Note: this will never happen on the first iteration. */ if (dc->dm_chain[seg].dc_addr == dmaend #if defined(HP320) /* only 16-bit count on 98620B */ && (sc->sc_type != DMA_B || dc->dm_chain[seg - 1].dc_count + tcount <= 65536) #endif ) { #ifdef DEBUG dmahits[unit]++; #endif dmaend += dc->dm_chain[seg].dc_count; dc->dm_chain[--seg].dc_count += tcount; } else { #ifdef DEBUG dmamisses[unit]++; #endif dmaend = dc->dm_chain[seg].dc_addr + dc->dm_chain[seg].dc_count; dc->dm_chain[seg].dc_count = tcount; } } dc->dm_cur = 0; dc->dm_last = --seg; dc->dm_flags = 0; /* * Set up the command word based on flags */ dc->dm_cmd = DMA_ENAB | DMA_IPL(sc->sc_isr.isr_ipl) | DMA_START; if ((flags & DMAGO_READ) == 0) dc->dm_cmd |= DMA_WRT; if (flags & DMAGO_LWORD) dc->dm_cmd |= DMA_LWORD; else if (flags & DMAGO_WORD) dc->dm_cmd |= DMA_WORD; if (flags & DMAGO_PRI) dc->dm_cmd |= DMA_PRI; #if defined(M68040) /* * On the 68040 we need to flush (push) the data cache before a * DMA (already done above) and flush again after DMA completes. * In theory we should only need to flush prior to a write DMA * and purge after a read DMA but if the entire page is not * involved in the DMA we might purge some valid data. */ if (mmutype == MMU_68040 && (flags & DMAGO_READ)) dc->dm_flags |= DMAF_PCFLUSH; #endif #if defined(CACHE_HAVE_PAC) /* * Remember if we need to flush external physical cache when * DMA is done. We only do this if we are reading (writing memory). */ if (ectype == EC_PHYS && (flags & DMAGO_READ)) dc->dm_flags |= DMAF_PCFLUSH; #endif #if defined(CACHE_HAVE_VAC) if (ectype == EC_VIRT && (flags & DMAGO_READ)) dc->dm_flags |= DMAF_VCFLUSH; #endif /* * Remember if we can skip the dma completion interrupt on * the last segment in the chain. */ if (flags & DMAGO_NOINT) { if (dc->dm_cur == dc->dm_last) dc->dm_cmd &= ~DMA_ENAB; else dc->dm_flags |= DMAF_NOINTR; } #ifdef DEBUG if (dmadebug & DDB_IO) { if (((dmadebug&DDB_WORD) && (dc->dm_cmd&DMA_WORD)) || ((dmadebug&DDB_LWORD) && (dc->dm_cmd&DMA_LWORD))) { printf("dmago: cmd %x, flags %x\n", dc->dm_cmd, dc->dm_flags); for (seg = 0; seg <= dc->dm_last; seg++) printf(" %d: %d@%p\n", seg, dc->dm_chain[seg].dc_count, dc->dm_chain[seg].dc_addr); } } dmatimo[unit] = 1; #endif DMA_ARM(sc, dc); } void dmastop(unit) int unit; { struct dma_softc *sc = &dma_softc; struct dma_channel *dc = &sc->sc_chan[unit]; #ifdef DEBUG if (dmadebug & DDB_FOLLOW) printf("dmastop(%d)\n", unit); dmatimo[unit] = 0; #endif DMA_CLEAR(dc); #if defined(CACHE_HAVE_PAC) || defined(M68040) if (dc->dm_flags & DMAF_PCFLUSH) { PCIA(); dc->dm_flags &= ~DMAF_PCFLUSH; } #endif #if defined(CACHE_HAVE_VAC) if (dc->dm_flags & DMAF_VCFLUSH) { /* * 320/350s have VACs that may also need flushing. * In our case we only flush the supervisor side * because we know that if we are DMAing to user * space, the physical pages will also be mapped * in kernel space (via vmapbuf) and hence cache- * inhibited by the pmap module due to the multiple * mapping. */ DCIS(); dc->dm_flags &= ~DMAF_VCFLUSH; } #endif /* * We may get this interrupt after a device service routine * has freed the dma channel. So, ignore the intr if there's * nothing on the queue. */ if (dc->dm_job != NULL) (*dc->dm_job->dq_done)(dc->dm_job->dq_softc); } int dmaintr(arg) void *arg; { struct dma_softc *sc = arg; struct dma_channel *dc; int i, stat; int found = 0; #ifdef DEBUG if (dmadebug & DDB_FOLLOW) printf("dmaintr\n"); #endif for (i = 0; i < NDMACHAN; i++) { dc = &sc->sc_chan[i]; stat = DMA_STAT(dc); if ((stat & DMA_INTR) == 0) continue; found++; #ifdef DEBUG if (dmadebug & DDB_IO) { if (((dmadebug&DDB_WORD) && (dc->dm_cmd&DMA_WORD)) || ((dmadebug&DDB_LWORD) && (dc->dm_cmd&DMA_LWORD))) printf("dmaintr: flags %x unit %d stat %x next %d\n", dc->dm_flags, i, stat, dc->dm_cur + 1); } if (stat & DMA_ARMED) printf("dma channel %d: intr when armed\n", i); #endif /* * Load the next segment, or finish up if we're done. */ dc->dm_cur++; if (dc->dm_cur <= dc->dm_last) { #ifdef DEBUG dmatimo[i] = 1; #endif /* * If we're the last segment, disable the * completion interrupt, if necessary. */ if (dc->dm_cur == dc->dm_last && (dc->dm_flags & DMAF_NOINTR)) dc->dm_cmd &= ~DMA_ENAB; DMA_CLEAR(dc); DMA_ARM(sc, dc); } else dmastop(i); } return(found); } #ifdef DEBUG void dmatimeout(arg) void *arg; { int i, s; struct dma_softc *sc = arg; for (i = 0; i < NDMACHAN; i++) { s = splbio(); if (dmatimo[i]) { if (dmatimo[i] > 1) printf("dma channel %d timeout #%d\n", i, dmatimo[i]-1); dmatimo[i]++; } splx(s); } timeout_add(&sc->sc_timeout, 30 * hz); } #endif