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Defer hooking up the DMA controller interrupt. Add a new funciton,

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dmacomputeipl(), which is called by drivers which use DMA once they've
hooked up their interrupts.  This new function computes the appropriate
ipl to use for the DMA controller and (re-)establishes it's interrupt.
This commit is contained in:
thorpej 1996-12-09 03:09:51 +00:00
parent 75a37ecc60
commit 0d6571ba4d
2 changed files with 33 additions and 8 deletions
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38
sys/arch/hp300/dev/dma.c
View File

@ -1,7 +1,7 @@
/* $NetBSD: dma.c,v 1.9 1996/10/13 03:14:09 christos Exp $ */
/* $NetBSD: dma.c,v 1.10 1996/12/09 03:09:51 thorpej Exp $ */
/*
* Copyright (c) 1995 Jason R. Thorpe.
* Copyright (c) 1995, 1996 Jason R. Thorpe. All rights reserved.
* Copyright (c) 1982, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
@ -54,7 +54,6 @@
#include <hp300/hp300/isr.h>
extern void isrlink();
extern void _insque();
extern void _remque();
extern u_int kvtop();
@ -89,6 +88,8 @@ struct dma_softc {
struct dmareg *sc_dmareg; /* pointer to our hardware */
struct dma_channel sc_chan[NDMACHAN]; /* 2 channels */
char sc_type; /* A, B, or C */
int sc_ipl; /* our interrupt level */
void *sc_ih; /* interrupt cookie */
} Dma_softc;
/* types */
@ -140,7 +141,7 @@ dmainit()
*
* 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
* DMAINTLVL is set to 3).
* splbio works out to ipl 3).
*/
if (badbaddr((char *)&dma->dma_id[2])) {
rev = 'B';
@ -181,8 +182,31 @@ dmainit()
printf("%s: 98620%c, 2 channels, %d bit\n", sc->sc_xname,
rev, (rev == 'B') ? 16 : 32);
/* Establish the interrupt handler */
isrlink(dmaintr, sc, DMAINTLVL, ISRPRI_BIO);
/*
* Defer hooking up our interrupt until the first
* DMA-using controller has hooked up theirs.
*/
sc->sc_ih = NULL;
}
/*
* Compute the ipl and (re)establish the interrupt handler
* for the DMA controller.
*/
void
dmacomputeipl()
{
struct dma_softc *sc = &Dma_softc;
if (sc->sc_ih != NULL)
isrunlink(sc->sc_ih);
/*
* Our interrupt level must be as high as the highest
* device using DMA (i.e. splbio).
*/
sc->sc_ipl = PSLTOIPL(hp300_bioipl);
sc->sc_ih = isrlink(dmaintr, sc, sc->sc_ipl, ISRPRI_BIO);
}
int
@ -342,7 +366,7 @@ dmago(unit, addr, count, flags)
/*
* Set up the command word based on flags
*/
dc->dm_cmd = DMA_ENAB | DMA_IPL(DMAINTLVL) | DMA_START;
dc->dm_cmd = DMA_ENAB | DMA_IPL(sc->sc_ipl) | DMA_START;
if ((flags & DMAGO_READ) == 0)
dc->dm_cmd |= DMA_WRT;
if (flags & DMAGO_LWORD)

3
sys/arch/hp300/dev/dmavar.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: dmavar.h,v 1.5 1995/03/28 18:16:03 jtc Exp $ */
/* $NetBSD: dmavar.h,v 1.6 1996/12/09 03:09:51 thorpej Exp $ */
/*
* Copyright (c) 1982, 1990, 1993
@ -50,4 +50,5 @@
#ifdef _KERNEL
extern void dmago(), dmafree();
extern int dmareq();
extern void dmacomputeipl __P((void));
#endif