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

272 lines
6.2 KiB
C

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/file.h>
#include <sys/buf.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <sys/uio.h>
#include <vm/vm.h>
#include <machine/pio.h>
#include <i386/isa/isa.h>
#include <i386/isa/dmavar.h>
#include <i386/isa/dmareg.h>
/* region of physical memory known to be contiguous */
vm_offset_t isaphysmem;
static caddr_t dma_bounce[8]; /* XXX */
static char bounced[8]; /* XXX */
#define MAXDMASZ 512 /* XXX */
/* high byte of address is stored in this port for i-th dma channel */
static short dmapageport[8] =
{ 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
/*
* 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 < 0 || chan > 7)
panic("isa_dmacascade: impossible request");
#endif
/* 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);
}
}
/*
* isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
* problems by using a bounce buffer.
*/
void
isa_dmastart(flags, addr, nbytes, chan)
int flags;
caddr_t addr;
vm_size_t nbytes;
int chan;
{
vm_offset_t phys;
int waport;
caddr_t newaddr;
#ifdef DIAGNOSTIC
if (chan < 0 || chan > 7 ||
((chan & 4) ? (nbytes >= (1<<17) || nbytes & 1 || (u_int)addr & 1) :
(nbytes >= (1<<16))))
panic("isa_dmastart: impossible request");
#endif
if (isa_dmarangecheck(addr, nbytes, chan)) {
if (dma_bounce[chan] == 0)
dma_bounce[chan] =
/*(caddr_t)malloc(MAXDMASZ, M_TEMP, M_WAITOK);*/
(caddr_t) isaphysmem + NBPG*chan;
bounced[chan] = 1;
newaddr = dma_bounce[chan];
*(int *) newaddr = 0; /* XXX */
/* copy bounce buffer on write */
if ((flags & B_READ) == 0)
bcopy(addr, newaddr, nbytes);
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 (flags & B_READ)
outb(DMA1_MODE, chan | DMA37MD_SINGLE | DMA37MD_WRITE);
else
outb(DMA1_MODE, chan | DMA37MD_SINGLE | DMA37MD_READ);
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 | DMA37SM_CLEAR);
} else {
/*
* Program one of DMA channels 4..7. These are
* word mode channels.
*/
/* set dma channel mode, and reset address ff */
if (flags & B_READ)
outb(DMA2_MODE, (chan & 3) | DMA37MD_SINGLE | DMA37MD_WRITE);
else
outb(DMA2_MODE, (chan & 3) | DMA37MD_SINGLE | DMA37MD_READ);
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, (chan & 3) | DMA37SM_CLEAR);
}
}
void
isa_dmaabort(chan)
int chan;
{
#ifdef DIAGNOSTIC
if (chan < 0 || chan > 7)
panic("isa_dmaabort: 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));
}
void
isa_dmadone(flags, addr, nbytes, chan)
int flags;
caddr_t addr;
vm_size_t nbytes;
int chan;
{
u_char tc;
#ifdef DIAGNOSTIC
if (chan < 0 || chan > 7)
panic("isa_dmadone: 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(dma_bounce[chan], addr, nbytes);
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
isa_dmarangecheck(va, length, chan)
vm_offset_t va;
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)
panic("isa_dmacheck: 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;
}
/* head of queue waiting for physmem to become available */
struct buf isa_physmemq;
/* blocked waiting for resource to become free for exclusive use */
static isaphysmemflag;
/* if waited for and call requested when free (B_CALL) */
static void (*isaphysmemunblock)(); /* needs to be a list */
/*
* Allocate contiguous physical memory for transfer, returning
* a *virtual* address to region. May block waiting for resource.
* (assumed to be called at splbio())
*/
caddr_t
isa_allocphysmem(caddr_t va, unsigned length, void (*func)()) {
isaphysmemunblock = func;
while (isaphysmemflag & B_BUSY) {
isaphysmemflag |= B_WANTED;
sleep((caddr_t)&isaphysmemflag, PRIBIO);
}
isaphysmemflag |= B_BUSY;
return((caddr_t)isaphysmem);
}
/*
* Free contiguous physical memory used for transfer.
* (assumed to be called at splbio())
*/
void
isa_freephysmem(caddr_t va, unsigned length) {
isaphysmemflag &= ~B_BUSY;
if (isaphysmemflag & B_WANTED) {
isaphysmemflag &= B_WANTED;
wakeup((caddr_t)&isaphysmemflag);
if (isaphysmemunblock)
(*isaphysmemunblock)();
}
}