Add a lock for DMA Channels to prevent two devices from using the same DMA

channel at the same time.  The functions isa_dma_acquire() and
isa_dma_release() should be used in all ISA drivers which call isa_dmastart().
This can be used more generally to register the usage of DMA channels in
any driver, but it is required for drivers using isa_dmastart() and friends.

Clean up sanity checks, error messages, etc.
Remove isa_dmadone_nobounce(), it is no longer needed

Reviewed by:	bde
This commit is contained in:
Sujal Patel 1996-04-08 19:38:57 +00:00
parent dadd5f3a95
commit 1dce4e5d60
3 changed files with 230 additions and 94 deletions

View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)isa.c 7.2 (Berkeley) 5/13/91
* $Id: isa.c,v 1.65 1996/03/10 07:04:44 gibbs Exp $
* $Id: isa.c,v 1.66 1996/04/07 17:32:13 bde Exp $
*/
/*
@ -125,7 +125,7 @@ static void conflict __P((struct isa_device *dvp, struct isa_device *tmpdvp,
char const *format));
static int haveseen __P((struct isa_device *dvp, struct isa_device *tmpdvp,
u_int checkbits));
static int isa_dmarangecheck __P((caddr_t va, unsigned length, unsigned chan));
static int isa_dmarangecheck __P((caddr_t va, u_int length, int chan));
static inthand2_t isa_strayintr;
static void register_imask __P((struct isa_device *dvp, u_int mask));
@ -559,26 +559,35 @@ isa_defaultirq()
}
static caddr_t dma_bouncebuf[8];
static unsigned dma_bouncebufsize[8];
static char dma_bounced[8];
static char dma_busy[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 */
#define VALID_DMA_MASK (7)
/* 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 };
/*
* Allocate a DMA channel.
* Setup a DMA channel's bounce buffer.
*/
void
isa_dmainit(chan, bouncebufsize)
unsigned chan;
unsigned bouncebufsize;
int chan;
u_int bouncebufsize;
{
void *buf;
if (chan > 7 || dma_bouncebuf[chan] != NULL)
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dmainit: channel out of range");
if (dma_bouncebuf[chan] != NULL)
panic("isa_dmainit: impossible request");
#endif
dma_bouncebufsize[chan] = bouncebufsize;
/* Try malloc() first. It works better if it works. */
@ -598,14 +607,68 @@ isa_dmainit(chan, bouncebufsize)
dma_bouncebuf[chan] = buf;
}
/*
* Register a DMA channel's usage. Usually called from a device driver
* in open() or during it's initialization.
*/
int
isa_dma_acquire(chan)
int chan;
{
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dma_acquire: channel out of range");
#endif
if (dma_inuse & (1 << chan)) {
printf("isa_dma_acquire: channel %d already in use\n", chan);
return (EBUSY);
}
dma_inuse |= (1 << chan);
return (0);
}
/*
* Unregister a DMA channel's usage. Usually called from a device driver
* during close() or during it's shutdown.
*/
void
isa_dma_release(chan)
int chan;
{
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dma_release: channel out of range");
if (dma_inuse & (1 << chan) == 0)
printf("isa_dma_release: channel %d not in use\n", chan);
#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);
}
/*
* isa_dmacascade(): program 8237 DMA controller channel to accept
* external dma control by a board.
*/
void isa_dmacascade(unsigned chan)
void isa_dmacascade(chan)
int chan;
{
if (chan > 7)
panic("isa_dmacascade: impossible request");
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dmacascade: channel out of range");
#endif
/* set dma channel mode, and set dma channel mode */
if ((chan & 4) == 0) {
@ -621,26 +684,34 @@ void isa_dmacascade(unsigned chan)
* isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
* problems by using a bounce buffer.
*/
void isa_dmastart(int flags, caddr_t addr, unsigned nbytes, unsigned chan)
{ vm_offset_t phys;
void isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
{
vm_offset_t phys;
int waport;
caddr_t newaddr;
if ( chan > 7
|| (chan < 4 && nbytes > (1<<16))
#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) || (u_int)addr & 1)))
panic("isa_dmastart: impossible request");
#ifdef notdef
if (dma_busy[chan])
printf("isa_dmastart: channel %u busy\n", chan);
if (dma_inuse & (1 << chan) == 0)
printf("isa_dmastart: channel %d not acquired\n", chan);
#endif
dma_busy[chan] = 1;
if (dma_busy & (1 << chan))
printf("isa_dmastart: channel %d busy\n", chan);
dma_busy |= (1 << chan);
if (isa_dmarangecheck(addr, nbytes, chan)) {
if (dma_bouncebuf[chan] == NULL
|| dma_bouncebufsize[chan] < nbytes)
panic("isa_dmastart: bad bounce buffer");
dma_bounced[chan] = 1;
dma_bounced |= (1 << chan);
newaddr = dma_bouncebuf[chan];
/* copy bounce buffer on write */
@ -723,36 +794,33 @@ void isa_dmastart(int flags, caddr_t addr, unsigned nbytes, unsigned chan)
}
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");
#ifdef notdef
if (!dma_busy[chan])
if (dma_inuse & (1 << chan) == 0)
printf("isa_dmadone: channel %d not acquired\n", chan);
#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) == 0)
printf("isa_dmadone: channel %d not busy\n", chan);
#endif
if (dma_bounced[chan]) {
if (dma_bounced & (1 << chan)) {
/* copy bounce buffer on read */
if (flags & B_READ)
bcopy(dma_bouncebuf[chan], addr, nbytes);
dma_bounced[chan] = 0;
dma_bounced &= ~(1 << chan);
}
dma_busy[chan] = 0;
}
void
isa_dmadone_nobounce(chan)
unsigned chan;
{
#ifdef notdef
if (!dma_busy[chan])
printf("isa_dmadone_nobounce: channel %u not busy\n", chan);
#endif
if (dma_bounced[chan]) {
printf("isa_dmadone_nobounce: channel %u bounced\n", chan);
dma_bounced[chan] = 0;
}
dma_busy[chan] = 0;
dma_busy &= ~(1 << chan);
}
/*
@ -763,7 +831,7 @@ isa_dmadone_nobounce(chan)
*/
static int
isa_dmarangecheck(caddr_t va, unsigned length, unsigned chan) {
isa_dmarangecheck(caddr_t va, u_int length, int chan) {
vm_offset_t phys, priorpage = 0, endva;
u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);

View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)isa.c 7.2 (Berkeley) 5/13/91
* $Id: isa.c,v 1.65 1996/03/10 07:04:44 gibbs Exp $
* $Id: isa.c,v 1.66 1996/04/07 17:32:13 bde Exp $
*/
/*
@ -125,7 +125,7 @@ static void conflict __P((struct isa_device *dvp, struct isa_device *tmpdvp,
char const *format));
static int haveseen __P((struct isa_device *dvp, struct isa_device *tmpdvp,
u_int checkbits));
static int isa_dmarangecheck __P((caddr_t va, unsigned length, unsigned chan));
static int isa_dmarangecheck __P((caddr_t va, u_int length, int chan));
static inthand2_t isa_strayintr;
static void register_imask __P((struct isa_device *dvp, u_int mask));
@ -559,26 +559,35 @@ isa_defaultirq()
}
static caddr_t dma_bouncebuf[8];
static unsigned dma_bouncebufsize[8];
static char dma_bounced[8];
static char dma_busy[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 */
#define VALID_DMA_MASK (7)
/* 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 };
/*
* Allocate a DMA channel.
* Setup a DMA channel's bounce buffer.
*/
void
isa_dmainit(chan, bouncebufsize)
unsigned chan;
unsigned bouncebufsize;
int chan;
u_int bouncebufsize;
{
void *buf;
if (chan > 7 || dma_bouncebuf[chan] != NULL)
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dmainit: channel out of range");
if (dma_bouncebuf[chan] != NULL)
panic("isa_dmainit: impossible request");
#endif
dma_bouncebufsize[chan] = bouncebufsize;
/* Try malloc() first. It works better if it works. */
@ -598,14 +607,68 @@ isa_dmainit(chan, bouncebufsize)
dma_bouncebuf[chan] = buf;
}
/*
* Register a DMA channel's usage. Usually called from a device driver
* in open() or during it's initialization.
*/
int
isa_dma_acquire(chan)
int chan;
{
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dma_acquire: channel out of range");
#endif
if (dma_inuse & (1 << chan)) {
printf("isa_dma_acquire: channel %d already in use\n", chan);
return (EBUSY);
}
dma_inuse |= (1 << chan);
return (0);
}
/*
* Unregister a DMA channel's usage. Usually called from a device driver
* during close() or during it's shutdown.
*/
void
isa_dma_release(chan)
int chan;
{
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dma_release: channel out of range");
if (dma_inuse & (1 << chan) == 0)
printf("isa_dma_release: channel %d not in use\n", chan);
#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);
}
/*
* isa_dmacascade(): program 8237 DMA controller channel to accept
* external dma control by a board.
*/
void isa_dmacascade(unsigned chan)
void isa_dmacascade(chan)
int chan;
{
if (chan > 7)
panic("isa_dmacascade: impossible request");
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dmacascade: channel out of range");
#endif
/* set dma channel mode, and set dma channel mode */
if ((chan & 4) == 0) {
@ -621,26 +684,34 @@ void isa_dmacascade(unsigned chan)
* isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
* problems by using a bounce buffer.
*/
void isa_dmastart(int flags, caddr_t addr, unsigned nbytes, unsigned chan)
{ vm_offset_t phys;
void isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
{
vm_offset_t phys;
int waport;
caddr_t newaddr;
if ( chan > 7
|| (chan < 4 && nbytes > (1<<16))
#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) || (u_int)addr & 1)))
panic("isa_dmastart: impossible request");
#ifdef notdef
if (dma_busy[chan])
printf("isa_dmastart: channel %u busy\n", chan);
if (dma_inuse & (1 << chan) == 0)
printf("isa_dmastart: channel %d not acquired\n", chan);
#endif
dma_busy[chan] = 1;
if (dma_busy & (1 << chan))
printf("isa_dmastart: channel %d busy\n", chan);
dma_busy |= (1 << chan);
if (isa_dmarangecheck(addr, nbytes, chan)) {
if (dma_bouncebuf[chan] == NULL
|| dma_bouncebufsize[chan] < nbytes)
panic("isa_dmastart: bad bounce buffer");
dma_bounced[chan] = 1;
dma_bounced |= (1 << chan);
newaddr = dma_bouncebuf[chan];
/* copy bounce buffer on write */
@ -723,36 +794,33 @@ void isa_dmastart(int flags, caddr_t addr, unsigned nbytes, unsigned chan)
}
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");
#ifdef notdef
if (!dma_busy[chan])
if (dma_inuse & (1 << chan) == 0)
printf("isa_dmadone: channel %d not acquired\n", chan);
#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) == 0)
printf("isa_dmadone: channel %d not busy\n", chan);
#endif
if (dma_bounced[chan]) {
if (dma_bounced & (1 << chan)) {
/* copy bounce buffer on read */
if (flags & B_READ)
bcopy(dma_bouncebuf[chan], addr, nbytes);
dma_bounced[chan] = 0;
dma_bounced &= ~(1 << chan);
}
dma_busy[chan] = 0;
}
void
isa_dmadone_nobounce(chan)
unsigned chan;
{
#ifdef notdef
if (!dma_busy[chan])
printf("isa_dmadone_nobounce: channel %u not busy\n", chan);
#endif
if (dma_bounced[chan]) {
printf("isa_dmadone_nobounce: channel %u bounced\n", chan);
dma_bounced[chan] = 0;
}
dma_busy[chan] = 0;
dma_busy &= ~(1 << chan);
}
/*
@ -763,7 +831,7 @@ isa_dmadone_nobounce(chan)
*/
static int
isa_dmarangecheck(caddr_t va, unsigned length, unsigned chan) {
isa_dmarangecheck(caddr_t va, u_int length, int chan) {
vm_offset_t phys, priorpage = 0, endva;
u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);

View File

@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* from: @(#)isa_device.h 7.1 (Berkeley) 5/9/91
* $Id: isa_device.h,v 1.27 1996/01/27 01:57:02 bde Exp $
* $Id: isa_device.h,v 1.28 1996/01/30 22:56:02 mpp Exp $
*/
#ifndef _I386_ISA_ISA_DEVICE_H_
@ -154,12 +154,12 @@ struct isa_device *
int haveseen_isadev __P((struct isa_device *dvp, u_int checkbits));
void isa_configure __P((void));
void isa_defaultirq __P((void));
void isa_dmacascade __P((unsigned chan));
void isa_dmacascade __P((int chan));
void isa_dmadone __P((int flags, caddr_t addr, int nbytes, int chan));
void isa_dmadone_nobounce __P((unsigned chan));
void isa_dmainit __P((unsigned chan, unsigned bouncebufsize));
void isa_dmastart __P((int flags, caddr_t addr, unsigned nbytes,
unsigned chan));
void isa_dmainit __P((int chan, u_int bouncebufsize));
void isa_dmastart __P((int flags, caddr_t addr, u_int nbytes, int chan));
int isa_dma_acquire __P((int chan));
void isa_dma_release __P((int chan));
int isa_externalize __P((struct isa_device *id, struct sysctl_req *req));
int isa_generic_externalize __P((struct kern_devconf *kdc,
struct sysctl_req *req));