Import sources from 2011-03-30 iso image

1 files changed, 264 insertions, 0 deletions

diff --git a/sys/src/9/pc/dma.c b/sys/src/9/pc/dma.c
new file mode 100755
index 000000000..7ecbc5f4a
--- /dev/null
+++ b/sys/src/9/pc/dma.c
@@ -0,0 +1,264 @@
+#include	"u.h"
+#include	"../port/lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+
+typedef struct DMAport	DMAport;
+typedef struct DMA	DMA;
+typedef struct DMAxfer	DMAxfer;
+
+/*
+ *  state of a dma transfer
+ */
+struct DMAxfer
+{
+	ulong	bpa;		/* bounce buffer physical address */
+	void*	bva;		/* bounce buffer virtual address */
+	int	blen;		/* bounce buffer length */
+	void*	va;		/* virtual address destination/src */
+	long	len;		/* bytes to be transferred */
+	int	isread;
+};
+
+/*
+ *  the dma controllers.  the first half of this structure specifies
+ *  the I/O ports used by the DMA controllers.
+ */
+struct DMAport
+{
+	uchar	addr[4];	/* current address (4 channels) */
+	uchar	count[4];	/* current count (4 channels) */
+	uchar	page[4];	/* page registers (4 channels) */
+	uchar	cmd;		/* command status register */
+	uchar	req;		/* request registers */
+	uchar	sbm;		/* single bit mask register */
+	uchar	mode;		/* mode register */
+	uchar	cbp;		/* clear byte pointer */
+	uchar	mc;		/* master clear */
+	uchar	cmask;		/* clear mask register */
+	uchar	wam;		/* write all mask register bit */
+};
+
+struct DMA
+{
+	DMAport;
+	int	shift;
+	Lock;
+	DMAxfer	x[4];
+};
+
+DMA dma[2] = {
+	{ 0x00, 0x02, 0x04, 0x06,
+	  0x01, 0x03, 0x05, 0x07,
+	  0x87, 0x83, 0x81, 0x82,
+	  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+	 0 },
+
+	{ 0xc0, 0xc4, 0xc8, 0xcc,
+	  0xc2, 0xc6, 0xca, 0xce,
+	  0x8f, 0x8b, 0x89, 0x8a,
+	  0xd0, 0xd2, 0xd4, 0xd6, 0xd8, 0xda, 0xdc, 0xde,
+	 1 },
+};
+
+extern int i8237dma;
+static void* i8237bva[2];
+static int i8237used;
+
+/*
+ *  DMA must be in the first 16MB.  This gets called early by the
+ *  initialisation routines of any devices which require DMA to ensure
+ *  the allocated bounce buffers are below the 16MB limit.
+ */
+void
+_i8237alloc(void)
+{
+	void* bva;
+
+	if(i8237dma <= 0)
+		return;
+	if(i8237dma > 2)
+		i8237dma = 2;
+
+	bva = xspanalloc(64*1024*i8237dma, BY2PG, 64*1024);
+	if(bva == nil || PADDR(bva)+64*1024*i8237dma > 16*MB){
+		/*
+		 * This will panic with the current
+		 * implementation of xspanalloc().
+		if(bva != nil)
+			xfree(bva);
+		 */
+		return;
+	}
+
+	i8237bva[0] = bva;
+	if(i8237dma == 2)
+		i8237bva[1] = ((uchar*)i8237bva[0])+64*1024;
+}
+
+/*
+ *  DMA must be in the first 16MB.  This gets called early by the
+ *  initialisation routines of any devices which require DMA to ensure
+ *  the allocated bounce buffers are below the 16MB limit.
+ */
+int
+dmainit(int chan, int maxtransfer)
+{
+	DMA *dp;
+	DMAxfer *xp;
+	static int once;
+
+	if(once == 0){
+		if(ioalloc(0x00, 0x10, 0, "dma") < 0
+		|| ioalloc(0x80, 0x10, 0, "dma") < 0
+		|| ioalloc(0xd0, 0x10, 0, "dma") < 0)
+			panic("dmainit");
+		once = 1;
+	}
+
+	if(maxtransfer > 64*1024)
+		maxtransfer = 64*1024;
+
+	dp = &dma[(chan>>2)&1];
+	chan = chan & 3;
+	xp = &dp->x[chan];
+	if(xp->bva != nil){
+		if(xp->blen < maxtransfer)
+			return 1;
+		return 0;
+	}
+
+	if(i8237used >= i8237dma || i8237bva[i8237used] == nil){
+		print("no i8237 DMA bounce buffer < 16MB\n");
+		return 1;
+	}
+	xp->bva = i8237bva[i8237used++];
+	xp->bpa = PADDR(xp->bva);
+	xp->blen = maxtransfer;
+	xp->len = 0;
+	xp->isread = 0;
+
+	return 0;
+}
+
+/*
+ *  setup a dma transfer.  if the destination is not in kernel
+ *  memory, allocate a page for the transfer.
+ *
+ *  we assume BIOS has set up the command register before we
+ *  are booted.
+ *
+ *  return the updated transfer length (we can't transfer across 64k
+ *  boundaries)
+ */
+long
+dmasetup(int chan, void *va, long len, int isread)
+{
+	DMA *dp;
+	ulong pa;
+	uchar mode;
+	DMAxfer *xp;
+
+	dp = &dma[(chan>>2)&1];
+	chan = chan & 3;
+	xp = &dp->x[chan];
+
+	/*
+	 *  if this isn't kernel memory or crossing 64k boundary or above 16 meg
+	 *  use the bounce buffer.
+	 */
+	if((ulong)va < KZERO 
+	|| ((pa=PADDR(va))&0xFFFF0000) != ((pa+len)&0xFFFF0000)
+	|| pa >= 16*MB){
+		if(xp->bva == nil)
+			return -1;
+		if(len > xp->blen)
+			len = xp->blen;
+		if(!isread)
+			memmove(xp->bva, va, len);
+		xp->va = va;
+		xp->len = len;
+		xp->isread = isread;
+		pa = xp->bpa;
+	}
+	else
+		xp->len = 0;
+
+	/*
+	 * this setup must be atomic
+	 */
+	ilock(dp);
+	mode = (isread ? 0x44 : 0x48) | chan;
+	outb(dp->mode, mode);	/* single mode dma (give CPU a chance at mem) */
+	outb(dp->page[chan], pa>>16);
+	outb(dp->cbp, 0);		/* set count & address to their first byte */
+	outb(dp->addr[chan], pa>>dp->shift);		/* set address */
+	outb(dp->addr[chan], pa>>(8+dp->shift));
+	outb(dp->count[chan], (len>>dp->shift)-1);		/* set count */
+	outb(dp->count[chan], ((len>>dp->shift)-1)>>8);
+	outb(dp->sbm, chan);		/* enable the channel */
+	iunlock(dp);
+
+	return len;
+}
+
+int
+dmadone(int chan)
+{
+	DMA *dp;
+
+	dp = &dma[(chan>>2)&1];
+	chan = chan & 3;
+
+	return inb(dp->cmd) & (1<<chan);
+}
+
+/*
+ *  this must be called after a dma has been completed.
+ *
+ *  if a page has been allocated for the dma,
+ *  copy the data into the actual destination
+ *  and free the page.
+ */
+void
+dmaend(int chan)
+{
+	DMA *dp;
+	DMAxfer *xp;
+
+	dp = &dma[(chan>>2)&1];
+	chan = chan & 3;
+
+	/*
+	 *  disable the channel
+	 */
+	ilock(dp);
+	outb(dp->sbm, 4|chan);
+	iunlock(dp);
+
+	xp = &dp->x[chan];
+	if(xp->len == 0 || !xp->isread)
+		return;
+
+	/*
+	 *  copy out of temporary page
+	 */
+	memmove(xp->va, xp->bva, xp->len);
+	xp->len = 0;
+}
+
+/*
+int
+dmacount(int chan)
+{
+	int     retval;
+	DMA     *dp;
+ 
+	dp = &dma[(chan>>2)&1];
+	outb(dp->cbp, 0);
+	retval = inb(dp->count[chan]);
+	retval |= inb(dp->count[chan]) << 8;
+	return((retval<<dp->shift)+1);
+}
+ */