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| Current File : //usr/src/sys/x86/isa/isa_dma.c |
/*-
* 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.
* 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/x86/isa/isa_dma.c 233924 2012-04-05 16:05:35Z jhb $");
/*
* code to manage AT bus
*
* 92/08/18 Frank P. MacLachlan (fpm@crash.cts.com):
* Fixed uninitialized variable problem and added code to deal
* with DMA page boundaries in isa_dmarangecheck(). Fixed word
* mode DMA count compution and reorganized DMA setup code in
* isa_dmastart()
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <isa/isareg.h>
#include <isa/isavar.h>
#include <isa/isa_dmareg.h>
#define ISARAM_END RAM_END
static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
static caddr_t dma_bouncebuf[8];
static u_int dma_bouncebufsize[8];
static u_int8_t dma_bounced = 0;
static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */
static u_int8_t dma_inuse = 0; /* User for acquire/release */
static u_int8_t dma_auto_mode = 0;
static struct mtx isa_dma_lock;
MTX_SYSINIT(isa_dma_lock, &isa_dma_lock, "isa DMA lock", MTX_DEF);
#define VALID_DMA_MASK (7)
/* high byte of address is stored in this port for i-th dma channel */
static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
/*
* Setup a DMA channel's bounce buffer.
*/
int
isa_dma_init(int chan, u_int bouncebufsize, int flag)
{
void *buf;
int contig;
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dma_init: channel out of range");
#endif
/* Try malloc() first. It works better if it works. */
buf = malloc(bouncebufsize, M_DEVBUF, flag);
if (buf != NULL) {
if (isa_dmarangecheck(buf, bouncebufsize, chan) != 0) {
free(buf, M_DEVBUF);
buf = NULL;
}
contig = 0;
}
if (buf == NULL) {
buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful,
1ul, chan & 4 ? 0x20000ul : 0x10000ul);
contig = 1;
}
if (buf == NULL)
return (ENOMEM);
mtx_lock(&isa_dma_lock);
/*
* If a DMA channel is shared, both drivers have to call isa_dma_init
* since they don't know that the other driver will do it.
* Just return if we're already set up good.
* XXX: this only works if they agree on the bouncebuf size. This
* XXX: is typically the case since they are multiple instances of
* XXX: the same driver.
*/
if (dma_bouncebuf[chan] != NULL) {
if (contig)
contigfree(buf, bouncebufsize, M_DEVBUF);
else
free(buf, M_DEVBUF);
mtx_unlock(&isa_dma_lock);
return (0);
}
dma_bouncebufsize[chan] = bouncebufsize;
dma_bouncebuf[chan] = buf;
mtx_unlock(&isa_dma_lock);
return (0);
}
/*
* Register a DMA channel's usage. Usually called from a device driver
* in open() or during its initialization.
*/
int
isa_dma_acquire(chan)
int chan;
{
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dma_acquire: channel out of range");
#endif
mtx_lock(&isa_dma_lock);
if (dma_inuse & (1 << chan)) {
printf("isa_dma_acquire: channel %d already in use\n", chan);
mtx_unlock(&isa_dma_lock);
return (EBUSY);
}
dma_inuse |= (1 << chan);
dma_auto_mode &= ~(1 << chan);
mtx_unlock(&isa_dma_lock);
return (0);
}
/*
* Unregister a DMA channel's usage. Usually called from a device driver
* during close() or during its shutdown.
*/
void
isa_dma_release(chan)
int chan;
{
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dma_release: channel out of range");
mtx_lock(&isa_dma_lock);
if ((dma_inuse & (1 << chan)) == 0)
printf("isa_dma_release: channel %d not in use\n", chan);
#else
mtx_lock(&isa_dma_lock);
#endif
if (dma_busy & (1 << chan)) {
dma_busy &= ~(1 << chan);
/*
* XXX We should also do "dma_bounced &= (1 << chan);"
* because we are acting on behalf of isa_dmadone() which
* was not called to end the last DMA operation. This does
* not matter now, but it may in the future.
*/
}
dma_inuse &= ~(1 << chan);
dma_auto_mode &= ~(1 << chan);
mtx_unlock(&isa_dma_lock);
}
/*
* isa_dmacascade(): program 8237 DMA controller channel to accept
* external dma control by a board.
*/
void
isa_dmacascade(chan)
int chan;
{
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dmacascade: channel out of range");
#endif
mtx_lock(&isa_dma_lock);
/* 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);
}
mtx_unlock(&isa_dma_lock);
}
/*
* isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
* problems by using a bounce buffer.
*/
void
isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
{
vm_paddr_t phys;
int waport;
caddr_t newaddr;
int dma_range_checked;
dma_range_checked = isa_dmarangecheck(addr, nbytes, chan);
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dmastart: channel out of range");
if ((chan < 4 && nbytes > (1<<16))
|| (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))
panic("isa_dmastart: impossible request");
mtx_lock(&isa_dma_lock);
if ((dma_inuse & (1 << chan)) == 0)
printf("isa_dmastart: channel %d not acquired\n", chan);
#else
mtx_lock(&isa_dma_lock);
#endif
#if 0
/*
* XXX This should be checked, but drivers like ad1848 only call
* isa_dmastart() once because they use Auto DMA mode. If we
* leave this in, drivers that do this will print this continuously.
*/
if (dma_busy & (1 << chan))
printf("isa_dmastart: channel %d busy\n", chan);
#endif
dma_busy |= (1 << chan);
if (dma_range_checked) {
if (dma_bouncebuf[chan] == NULL
|| dma_bouncebufsize[chan] < nbytes)
panic("isa_dmastart: bad bounce buffer");
dma_bounced |= (1 << chan);
newaddr = dma_bouncebuf[chan];
/* copy bounce buffer on write */
if (!(flags & ISADMA_READ))
bcopy(addr, newaddr, nbytes);
addr = newaddr;
}
/* translate to physical */
phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
if (flags & ISADMA_RAW) {
dma_auto_mode |= (1 << chan);
} else {
dma_auto_mode &= ~(1 << chan);
}
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 ISADMA_RAW flag is set, then use autoinitialise mode */
if (flags & ISADMA_RAW) {
if (flags & ISADMA_READ)
outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
else
outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
}
else
if (flags & ISADMA_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, chan);
} else {
/*
* Program one of DMA channels 4..7. These are
* word mode channels.
*/
/* set dma channel mode, and reset address ff */
/* If ISADMA_RAW flag is set, then use autoinitialise mode */
if (flags & ISADMA_RAW) {
if (flags & ISADMA_READ)
outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
else
outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
}
else
if (flags & ISADMA_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 - 4);
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, chan & 3);
}
mtx_unlock(&isa_dma_lock);
}
void
isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
{
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dmadone: channel out of range");
if ((dma_inuse & (1 << chan)) == 0)
printf("isa_dmadone: channel %d not acquired\n", chan);
#endif
mtx_lock(&isa_dma_lock);
if (((dma_busy & (1 << chan)) == 0) &&
(dma_auto_mode & (1 << chan)) == 0 )
printf("isa_dmadone: channel %d not busy\n", chan);
if ((dma_auto_mode & (1 << chan)) == 0)
outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
if (dma_bounced & (1 << chan)) {
/* copy bounce buffer on read */
if (flags & ISADMA_READ)
bcopy(dma_bouncebuf[chan], addr, nbytes);
dma_bounced &= ~(1 << chan);
}
dma_busy &= ~(1 << chan);
mtx_unlock(&isa_dma_lock);
}
/*
* 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.
*/
static int
isa_dmarangecheck(caddr_t va, u_int length, int chan)
{
vm_paddr_t phys, priorpage = 0;
vm_offset_t endva;
u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);
endva = (vm_offset_t)round_page((vm_offset_t)va + length);
for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
if (phys == 0)
panic("isa_dmacheck: no physical page present");
if (phys >= ISARAM_END)
return (1);
if (priorpage) {
if (priorpage + PAGE_SIZE != phys)
return (1);
/* check if crossing a DMA page boundary */
if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
return (1);
}
priorpage = phys;
}
return (0);
}
/*
* Query the progress of a transfer on a DMA channel.
*
* To avoid having to interrupt a transfer in progress, we sample
* each of the high and low databytes twice, and apply the following
* logic to determine the correct count.
*
* Reads are performed with interrupts disabled, thus it is to be
* expected that the time between reads is very small. At most
* one rollover in the low count byte can be expected within the
* four reads that are performed.
*
* There are three gaps in which a rollover can occur :
*
* - read low1
* gap1
* - read high1
* gap2
* - read low2
* gap3
* - read high2
*
* If a rollover occurs in gap1 or gap2, the low2 value will be
* greater than the low1 value. In this case, low2 and high2 are a
* corresponding pair.
*
* In any other case, low1 and high1 can be considered to be correct.
*
* The function returns the number of bytes remaining in the transfer,
* or -1 if the channel requested is not active.
*
*/
static int
isa_dmastatus_locked(int chan)
{
u_long cnt = 0;
int ffport, waport;
u_long low1, high1, low2, high2;
mtx_assert(&isa_dma_lock, MA_OWNED);
/* channel active? */
if ((dma_inuse & (1 << chan)) == 0) {
printf("isa_dmastatus: channel %d not active\n", chan);
return(-1);
}
/* channel busy? */
if (((dma_busy & (1 << chan)) == 0) &&
(dma_auto_mode & (1 << chan)) == 0 ) {
printf("chan %d not busy\n", chan);
return -2 ;
}
if (chan < 4) { /* low DMA controller */
ffport = DMA1_FFC;
waport = DMA1_CHN(chan) + 1;
} else { /* high DMA controller */
ffport = DMA2_FFC;
waport = DMA2_CHN(chan - 4) + 2;
}
disable_intr(); /* no interrupts Mr Jones! */
outb(ffport, 0); /* clear register LSB flipflop */
low1 = inb(waport);
high1 = inb(waport);
outb(ffport, 0); /* clear again */
low2 = inb(waport);
high2 = inb(waport);
enable_intr(); /* enable interrupts again */
/*
* Now decide if a wrap has tried to skew our results.
* Note that after TC, the count will read 0xffff, while we want
* to return zero, so we add and then mask to compensate.
*/
if (low1 >= low2) {
cnt = (low1 + (high1 << 8) + 1) & 0xffff;
} else {
cnt = (low2 + (high2 << 8) + 1) & 0xffff;
}
if (chan >= 4) /* high channels move words */
cnt *= 2;
return(cnt);
}
int
isa_dmastatus(int chan)
{
int status;
mtx_lock(&isa_dma_lock);
status = isa_dmastatus_locked(chan);
mtx_unlock(&isa_dma_lock);
return (status);
}
/*
* Reached terminal count yet ?
*/
int
isa_dmatc(int chan)
{
if (chan < 4)
return(inb(DMA1_STATUS) & (1 << chan));
else
return(inb(DMA2_STATUS) & (1 << (chan & 3)));
}
/*
* Stop a DMA transfer currently in progress.
*/
int
isa_dmastop(int chan)
{
int status;
mtx_lock(&isa_dma_lock);
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);
mtx_unlock(&isa_dma_lock);
return -2 ;
}
if ((chan & 4) == 0) {
outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
} else {
outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
}
status = isa_dmastatus_locked(chan);
mtx_unlock(&isa_dma_lock);
return (status);
}
/*
* 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);