290617ea0e
When two drivers share an ISA DMA channel, they both call isa_dmainit() and the second call fails if DIAGNOSTIC is on. If isa_dmainit() was already called successfully, just return silently. This only works if both drivers agree on the bounce buffer size, but since sharing DMA is usually only possible on very special hardware and then typically only for devices of the same type (which would have multiple instances of the same device driver), this is not a problem in practice.
560 lines
15 KiB
C
560 lines
15 KiB
C
/*-
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* Copyright (c) 1991 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* William Jolitz.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)isa.c 7.2 (Berkeley) 5/13/91
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* code to manage AT bus
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*
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* 92/08/18 Frank P. MacLachlan (fpm@crash.cts.com):
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* Fixed uninitialized variable problem and added code to deal
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* with DMA page boundaries in isa_dmarangecheck(). Fixed word
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* mode DMA count compution and reorganized DMA setup code in
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* isa_dmastart()
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bus.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/lock.h>
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#include <sys/proc.h>
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#include <sys/mutex.h>
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#include <sys/module.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/pmap.h>
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#include <i386/isa/isa.h>
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#include <dev/ic/i8237.h>
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#include <isa/isavar.h>
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/*
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** Register definitions for DMA controller 1 (channels 0..3):
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*/
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#define DMA1_CHN(c) (IO_DMA1 + 1*(2*(c))) /* addr reg for channel c */
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#define DMA1_SMSK (IO_DMA1 + 1*10) /* single mask register */
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#define DMA1_MODE (IO_DMA1 + 1*11) /* mode register */
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#define DMA1_FFC (IO_DMA1 + 1*12) /* clear first/last FF */
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/*
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** Register definitions for DMA controller 2 (channels 4..7):
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*/
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#define DMA2_CHN(c) (IO_DMA2 + 2*(2*(c))) /* addr reg for channel c */
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#define DMA2_SMSK (IO_DMA2 + 2*10) /* single mask register */
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#define DMA2_MODE (IO_DMA2 + 2*11) /* mode register */
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#define DMA2_FFC (IO_DMA2 + 2*12) /* clear first/last FF */
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static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
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static caddr_t dma_bouncebuf[8];
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static u_int dma_bouncebufsize[8];
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static u_int8_t dma_bounced = 0;
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static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */
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static u_int8_t dma_inuse = 0; /* User for acquire/release */
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static u_int8_t dma_auto_mode = 0;
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#define VALID_DMA_MASK (7)
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/* high byte of address is stored in this port for i-th dma channel */
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static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
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/*
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* Setup a DMA channel's bounce buffer.
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*/
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void
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isa_dmainit(chan, bouncebufsize)
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int chan;
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u_int bouncebufsize;
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{
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void *buf;
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/*
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* If a DMA channel is shared, both drivers have to call isa_dmainit
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* since they don't know that the other driver will do it.
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* Just return if we're already set up good.
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* XXX: this only works if they agree on the bouncebuf size. This
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* XXX: is typically the case since they are multiple instances of
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* XXX: the same driver.
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*/
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if (dma_bouncebuf[chan] != NULL)
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return;
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dmainit: channel out of range");
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#endif
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dma_bouncebufsize[chan] = bouncebufsize;
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/* Try malloc() first. It works better if it works. */
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buf = malloc(bouncebufsize, M_DEVBUF, M_NOWAIT);
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if (buf != NULL) {
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if (isa_dmarangecheck(buf, bouncebufsize, chan) == 0) {
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dma_bouncebuf[chan] = buf;
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return;
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}
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free(buf, M_DEVBUF);
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}
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buf = contigmalloc(bouncebufsize, M_DEVBUF, M_NOWAIT, 0ul, 0xfffffful,
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1ul, chan & 4 ? 0x20000ul : 0x10000ul);
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if (buf == NULL)
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printf("isa_dmainit(%d, %d) failed\n", chan, bouncebufsize);
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else
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dma_bouncebuf[chan] = buf;
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}
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/*
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* Register a DMA channel's usage. Usually called from a device driver
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* in open() or during its initialization.
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*/
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int
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isa_dma_acquire(chan)
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int chan;
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{
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dma_acquire: channel out of range");
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#endif
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if (dma_inuse & (1 << chan)) {
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printf("isa_dma_acquire: channel %d already in use\n", chan);
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return (EBUSY);
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}
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dma_inuse |= (1 << chan);
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dma_auto_mode &= ~(1 << chan);
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return (0);
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}
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/*
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* Unregister a DMA channel's usage. Usually called from a device driver
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* during close() or during its shutdown.
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*/
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void
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isa_dma_release(chan)
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int chan;
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{
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dma_release: channel out of range");
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if ((dma_inuse & (1 << chan)) == 0)
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printf("isa_dma_release: channel %d not in use\n", chan);
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#endif
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if (dma_busy & (1 << chan)) {
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dma_busy &= ~(1 << chan);
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/*
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* XXX We should also do "dma_bounced &= (1 << chan);"
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* because we are acting on behalf of isa_dmadone() which
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* was not called to end the last DMA operation. This does
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* not matter now, but it may in the future.
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*/
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}
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dma_inuse &= ~(1 << chan);
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dma_auto_mode &= ~(1 << chan);
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}
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/*
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* isa_dmacascade(): program 8237 DMA controller channel to accept
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* external dma control by a board.
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*/
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void
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isa_dmacascade(chan)
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int chan;
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{
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dmacascade: channel out of range");
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#endif
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/* set dma channel mode, and set dma channel mode */
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if ((chan & 4) == 0) {
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outb(DMA1_MODE, DMA37MD_CASCADE | chan);
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outb(DMA1_SMSK, chan);
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} else {
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outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
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outb(DMA2_SMSK, chan & 3);
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}
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}
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/*
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* isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
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* problems by using a bounce buffer.
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*/
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void
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isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
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{
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vm_paddr_t phys;
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int waport;
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caddr_t newaddr;
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GIANT_REQUIRED;
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dmastart: channel out of range");
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if ((chan < 4 && nbytes > (1<<16))
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|| (chan >= 4 && (nbytes > (1<<17) || (u_int)addr & 1)))
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panic("isa_dmastart: impossible request");
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if ((dma_inuse & (1 << chan)) == 0)
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printf("isa_dmastart: channel %d not acquired\n", chan);
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#endif
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#if 0
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/*
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* XXX This should be checked, but drivers like ad1848 only call
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* isa_dmastart() once because they use Auto DMA mode. If we
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* leave this in, drivers that do this will print this continuously.
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*/
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if (dma_busy & (1 << chan))
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printf("isa_dmastart: channel %d busy\n", chan);
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#endif
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dma_busy |= (1 << chan);
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if (isa_dmarangecheck(addr, nbytes, chan)) {
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if (dma_bouncebuf[chan] == NULL
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|| dma_bouncebufsize[chan] < nbytes)
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panic("isa_dmastart: bad bounce buffer");
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dma_bounced |= (1 << chan);
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newaddr = dma_bouncebuf[chan];
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/* copy bounce buffer on write */
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if (!(flags & ISADMA_READ))
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bcopy(addr, newaddr, nbytes);
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addr = newaddr;
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}
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/* translate to physical */
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phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
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if (flags & ISADMA_RAW) {
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dma_auto_mode |= (1 << chan);
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} else {
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dma_auto_mode &= ~(1 << chan);
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}
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if ((chan & 4) == 0) {
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/*
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* Program one of DMA channels 0..3. These are
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* byte mode channels.
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*/
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/* set dma channel mode, and reset address ff */
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/* If ISADMA_RAW flag is set, then use autoinitialise mode */
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if (flags & ISADMA_RAW) {
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if (flags & ISADMA_READ)
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outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
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else
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outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
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}
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else
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if (flags & ISADMA_READ)
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outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
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else
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outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
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outb(DMA1_FFC, 0);
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/* send start address */
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waport = DMA1_CHN(chan);
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outb(waport, phys);
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outb(waport, phys>>8);
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outb(dmapageport[chan], phys>>16);
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/* send count */
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outb(waport + 1, --nbytes);
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outb(waport + 1, nbytes>>8);
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/* unmask channel */
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outb(DMA1_SMSK, chan);
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} else {
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/*
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* Program one of DMA channels 4..7. These are
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* word mode channels.
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*/
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/* set dma channel mode, and reset address ff */
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/* If ISADMA_RAW flag is set, then use autoinitialise mode */
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if (flags & ISADMA_RAW) {
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if (flags & ISADMA_READ)
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outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
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else
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outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
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}
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else
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if (flags & ISADMA_READ)
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outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
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else
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outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
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outb(DMA2_FFC, 0);
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/* send start address */
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waport = DMA2_CHN(chan - 4);
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outb(waport, phys>>1);
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outb(waport, phys>>9);
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outb(dmapageport[chan], phys>>16);
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/* send count */
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nbytes >>= 1;
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outb(waport + 2, --nbytes);
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outb(waport + 2, nbytes>>8);
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/* unmask channel */
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outb(DMA2_SMSK, chan & 3);
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}
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}
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void
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isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
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{
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#ifdef DIAGNOSTIC
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if (chan & ~VALID_DMA_MASK)
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panic("isa_dmadone: channel out of range");
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if ((dma_inuse & (1 << chan)) == 0)
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printf("isa_dmadone: channel %d not acquired\n", chan);
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#endif
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if (((dma_busy & (1 << chan)) == 0) &&
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(dma_auto_mode & (1 << chan)) == 0 )
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printf("isa_dmadone: channel %d not busy\n", chan);
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if ((dma_auto_mode & (1 << chan)) == 0)
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outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
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if (dma_bounced & (1 << chan)) {
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/* copy bounce buffer on read */
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if (flags & ISADMA_READ)
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bcopy(dma_bouncebuf[chan], addr, nbytes);
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dma_bounced &= ~(1 << chan);
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}
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dma_busy &= ~(1 << chan);
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}
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/*
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* Check for problems with the address range of a DMA transfer
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* (non-contiguous physical pages, outside of bus address space,
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* crossing DMA page boundaries).
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* Return true if special handling needed.
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*/
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static int
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isa_dmarangecheck(caddr_t va, u_int length, int chan)
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{
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vm_paddr_t phys, priorpage = 0;
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vm_offset_t endva;
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u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);
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GIANT_REQUIRED;
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endva = (vm_offset_t)round_page((vm_offset_t)va + length);
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for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
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phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
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#define ISARAM_END RAM_END
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if (phys == 0)
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panic("isa_dmacheck: no physical page present");
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if (phys >= ISARAM_END)
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return (1);
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if (priorpage) {
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if (priorpage + PAGE_SIZE != phys)
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return (1);
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/* check if crossing a DMA page boundary */
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if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
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return (1);
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}
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priorpage = phys;
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}
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return (0);
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}
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/*
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* Query the progress of a transfer on a DMA channel.
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*
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* To avoid having to interrupt a transfer in progress, we sample
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* each of the high and low databytes twice, and apply the following
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* logic to determine the correct count.
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*
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* Reads are performed with interrupts disabled, thus it is to be
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* expected that the time between reads is very small. At most
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* one rollover in the low count byte can be expected within the
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* four reads that are performed.
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*
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* There are three gaps in which a rollover can occur :
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*
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* - read low1
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* gap1
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* - read high1
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* gap2
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* - read low2
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* gap3
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* - read high2
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*
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* If a rollover occurs in gap1 or gap2, the low2 value will be
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* greater than the low1 value. In this case, low2 and high2 are a
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* corresponding pair.
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*
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* In any other case, low1 and high1 can be considered to be correct.
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*
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* The function returns the number of bytes remaining in the transfer,
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* or -1 if the channel requested is not active.
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*
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*/
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int
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isa_dmastatus(int chan)
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{
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u_long cnt = 0;
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int ffport, waport;
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u_long low1, high1, low2, high2;
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/* channel active? */
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if ((dma_inuse & (1 << chan)) == 0) {
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printf("isa_dmastatus: channel %d not active\n", chan);
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return(-1);
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}
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/* channel busy? */
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if (((dma_busy & (1 << chan)) == 0) &&
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(dma_auto_mode & (1 << chan)) == 0 ) {
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printf("chan %d not busy\n", chan);
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return -2 ;
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}
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if (chan < 4) { /* low DMA controller */
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ffport = DMA1_FFC;
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waport = DMA1_CHN(chan) + 1;
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} else { /* high DMA controller */
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ffport = DMA2_FFC;
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waport = DMA2_CHN(chan - 4) + 2;
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}
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disable_intr(); /* no interrupts Mr Jones! */
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outb(ffport, 0); /* clear register LSB flipflop */
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low1 = inb(waport);
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high1 = inb(waport);
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outb(ffport, 0); /* clear again */
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low2 = inb(waport);
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high2 = inb(waport);
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enable_intr(); /* enable interrupts again */
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/*
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* Now decide if a wrap has tried to skew our results.
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* Note that after TC, the count will read 0xffff, while we want
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* to return zero, so we add and then mask to compensate.
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*/
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if (low1 >= low2) {
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cnt = (low1 + (high1 << 8) + 1) & 0xffff;
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} else {
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cnt = (low2 + (high2 << 8) + 1) & 0xffff;
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}
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if (chan >= 4) /* high channels move words */
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cnt *= 2;
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return(cnt);
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}
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/*
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* Stop a DMA transfer currently in progress.
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*/
|
|
int
|
|
isa_dmastop(int chan)
|
|
{
|
|
if ((dma_inuse & (1 << chan)) == 0)
|
|
printf("isa_dmastop: channel %d not acquired\n", chan);
|
|
|
|
if (((dma_busy & (1 << chan)) == 0) &&
|
|
((dma_auto_mode & (1 << chan)) == 0)) {
|
|
printf("chan %d not busy\n", chan);
|
|
return -2 ;
|
|
}
|
|
|
|
if ((chan & 4) == 0) {
|
|
outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
|
|
} else {
|
|
outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
|
|
}
|
|
return(isa_dmastatus(chan));
|
|
}
|
|
|
|
/*
|
|
* Attach to the ISA PnP descriptor for the AT DMA controller
|
|
*/
|
|
static struct isa_pnp_id atdma_ids[] = {
|
|
{ 0x0002d041 /* PNP0200 */, "AT DMA controller" },
|
|
{ 0 }
|
|
};
|
|
|
|
static int
|
|
atdma_probe(device_t dev)
|
|
{
|
|
int result;
|
|
|
|
if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
|
|
device_quiet(dev);
|
|
return(result);
|
|
}
|
|
|
|
static int
|
|
atdma_attach(device_t dev)
|
|
{
|
|
return(0);
|
|
}
|
|
|
|
static device_method_t atdma_methods[] = {
|
|
/* Device interface */
|
|
DEVMETHOD(device_probe, atdma_probe),
|
|
DEVMETHOD(device_attach, atdma_attach),
|
|
DEVMETHOD(device_detach, bus_generic_detach),
|
|
DEVMETHOD(device_shutdown, bus_generic_shutdown),
|
|
DEVMETHOD(device_suspend, bus_generic_suspend),
|
|
DEVMETHOD(device_resume, bus_generic_resume),
|
|
{ 0, 0 }
|
|
};
|
|
|
|
static driver_t atdma_driver = {
|
|
"atdma",
|
|
atdma_methods,
|
|
1, /* no softc */
|
|
};
|
|
|
|
static devclass_t atdma_devclass;
|
|
|
|
DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
|
|
DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);
|