NetBSD/sys/arch/i386/isa/dma.c

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/*-
* Copyright (c) 1993 Charles Hannum.
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* from: @(#)isa.c 7.2 (Berkeley) 5/13/91
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* $Id: dma.c,v 1.4 1993/10/22 20:24:14 mycroft Exp $
*/
/*
* code to deal with ISA DMA
*/
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#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/syslog.h>
#include <sys/device.h>
#include <vm/vm.h>
#include <machine/cpu.h>
#include <machine/pio.h>
#include <i386/isa/isa.h>
#include <i386/isa/isavar.h>
#include <i386/isa/ic/i8237.h>
/*
** Register definitions for DMA controller 1 (channels 0..3):
*/
#define DMA1_CHN(c) (IO_DMA1 + 1*(2*(c))) /* addr reg for channel c */
#define DMA1_SR (IO_DMA1 + 1*8) /* status register */
#define DMA1_SMSK (IO_DMA1 + 1*10) /* single mask register */
#define DMA1_MODE (IO_DMA1 + 1*11) /* mode register */
#define DMA1_FFC (IO_DMA1 + 1*12) /* clear first/last FF */
/*
** Register definitions for DMA controller 2 (channels 4..7):
*/
#define DMA2_CHN(c) (IO_DMA2 + 2*(2*(c))) /* addr reg for channel c */
#define DMA2_SR (IO_DMA2 + 2*8) /* status register */
#define DMA2_SMSK (IO_DMA2 + 2*10) /* single mask register */
#define DMA2_MODE (IO_DMA2 + 2*11) /* mode register */
#define DMA2_FFC (IO_DMA2 + 2*12) /* clear first/last FF */
/* region of physical memory known to be contiguous */
caddr_t isaphysmem;
static caddr_t bouncebuf[8]; /* XXX */
static caddr_t bounced[8]; /* XXX */
static vm_size_t bouncesize[8]; /* XXX */
/* high byte of address is stored in this port for i-th dma channel */
static u_short dmapageport[8] =
{ 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
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/*
* at_setup_dmachan(): allocate bounce buffer and check for conflicts.
*
* XXX
* This sucks. We should be able to bounce more than NBPG bytes, but I
* don't feel like writing the code to do contiguous allocation right now.
*/
void
at_setup_dmachan(chan, max)
int chan;
u_long max;
{
#ifdef DIAGNOSTIC
if (chan > 7 || chan < 0)
panic("at_setup_dmachan: impossible request");
if (max > NBPG)
panic("at_setup_dmachan: what a lose");
#endif
/* XXX check for drq conflict? */
bouncebuf[chan] = (caddr_t) isaphysmem + NBPG*chan;
}
/*
* at_dma_cascade(): program 8237 DMA controller channel to accept
* external dma control by a board.
*/
void
at_dma_cascade(chan)
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int chan;
{
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#ifdef DIAGNOSTIC
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if (chan > 7 || chan < 0)
panic("at_dma_cascade: impossible request");
#endif
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/* XXX check for drq conflict? */
/* set dma channel mode, and set dma channel mode */
if ((chan & 4) == 0) {
outb(DMA1_MODE, DMA37MD_CASCADE | chan);
outb(DMA1_SMSK, chan);
} else {
outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
outb(DMA2_SMSK, chan & 3);
}
}
/*
* at_dma(): program 8237 DMA controller channel, avoid page alignment
* problems by using a bounce buffer.
*/
void
at_dma(read, addr, nbytes, chan)
int read;
caddr_t addr;
vm_size_t nbytes;
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int chan;
{
vm_offset_t phys;
int waport;
caddr_t newaddr;
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#ifdef DIAGNOSTIC
if (chan > 7 || chan < 0 ||
(chan < 4 && nbytes > (1<<16)) ||
(chan >= 4 && (nbytes > (1<<17) || nbytes & 1 || (u_int)addr & 1)))
panic("at_dma: impossible request");
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#endif
if (at_dma_rangecheck((vm_offset_t)addr, nbytes, chan)) {
if (bouncebuf[chan] == 0)
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/* some twit forgot to call at_setup_dmachan() */
panic("at_dma: no bounce buffer");
/* XXX totally braindead; NBPG is not enough */
if (nbytes > NBPG)
panic("at_dma: transfer too large");
bouncesize[chan] = nbytes;
newaddr = bouncebuf[chan];
/* copy bounce buffer on write */
if (!read) {
bcopy(addr, newaddr, nbytes);
bounced[chan] = 0;
} else
bounced[chan] = addr;
addr = newaddr;
}
/* translate to physical */
phys = pmap_extract(pmap_kernel(), (vm_offset_t)addr);
if ((chan & 4) == 0) {
/*
* Program one of DMA channels 0..3. These are
* byte mode channels.
*/
/* set dma channel mode, and reset address ff */
if (read)
outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
else
outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
outb(DMA1_FFC, 0);
/* send start address */
waport = DMA1_CHN(chan);
outb(waport, phys);
outb(waport, phys>>8);
outb(dmapageport[chan], phys>>16);
/* send count */
outb(waport + 1, --nbytes);
outb(waport + 1, nbytes>>8);
/* unmask channel */
outb(DMA1_SMSK, DMA37SM_CLEAR | chan);
} else {
/*
* Program one of DMA channels 4..7. These are
* word mode channels.
*/
/* set dma channel mode, and reset address ff */
if (read)
outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
else
outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
outb(DMA2_FFC, 0);
/* send start address */
waport = DMA2_CHN(chan & 3);
outb(waport, phys>>1);
outb(waport, phys>>9);
outb(dmapageport[chan], phys>>16);
/* send count */
nbytes >>= 1;
outb(waport + 2, --nbytes);
outb(waport + 2, nbytes>>8);
/* unmask channel */
outb(DMA2_SMSK, DMA37SM_CLEAR | (chan & 3));
}
}
/*
* Abort a DMA request, clearing the bounce buffer, if any.
*/
void
at_dma_abort(chan)
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int chan;
{
#ifdef DIAGNOSTIC
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if (chan > 7 || chan < 0)
panic("at_dma_abort: impossible request");
#endif
bounced[chan] = 0;
/* mask channel */
if ((chan & 4) == 0)
outb(DMA1_SMSK, DMA37SM_SET | chan);
else
outb(DMA2_SMSK, DMA37SM_SET | (chan & 3));
}
/*
* End a DMA request, copying data from the bounce buffer, if any,
* when reading.
*/
void
at_dma_terminate(chan)
unsigned chan;
{
u_char tc;
#ifdef DIAGNOSTIC
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if (chan > 7 || chan < 0)
panic("at_dma_terminate: impossible request");
#endif
/* check that the terminal count was reached */
if ((chan & 4) == 0)
tc = inb(DMA1_SR) & (1 << chan);
else
tc = inb(DMA2_SR) & (1 << (chan & 3));
if (tc == 0)
/* XXX probably should panic or something */
log(LOG_ERR, "dma channel %d not finished\n", chan);
/* copy bounce buffer on read */
if (bounced[chan]) {
bcopy(bouncebuf[chan], bounced[chan], bouncesize[chan]);
bounced[chan] = 0;
}
/* mask channel */
if ((chan & 4) == 0)
outb(DMA1_SMSK, DMA37SM_SET | chan);
else
outb(DMA2_SMSK, DMA37SM_SET | (chan & 3));
}
/*
* Check for problems with the address range of a DMA transfer
* (non-contiguous physical pages, outside of bus address space,
* crossing DMA page boundaries).
* Return true if special handling needed.
*/
int
at_dma_rangecheck(va, length, chan)
vm_offset_t va;
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u_long length;
int chan;
{
vm_offset_t phys, priorpage = 0, endva;
u_int dma_pgmsk = (chan&4) ? ~(128*1024-1) : ~(64*1024-1);
endva = round_page(va + length);
for (; va < endva ; va += NBPG) {
phys = trunc_page(pmap_extract(pmap_kernel(), va));
if (phys == 0)
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panic("at_dma_rangecheck: no physical page present");
if (phys >= (1<<24))
return 1;
if (priorpage) {
if (priorpage + NBPG != phys)
return 1;
/* check if crossing a DMA page boundary */
if ((priorpage ^ phys) & dma_pgmsk)
return 1;
}
priorpage = phys;
}
return 0;
}