Support bounce buffers for ISA DMA on the alpha. This is required for the

irongate chipset (used in the UP1000) which does not support scatter/gather
DMA.  We'll still use scatter gather if the core logic chipset supports it.

Reviewed by: dfr

7 files changed, 39 insertions, 16 deletions

diff --git a/sys/alpha/alpha/busdma_machdep.c b/sys/alpha/alpha/busdma_machdep.c
index d01433b..aa92602 100644
--- a/sys/alpha/alpha/busdma_machdep.c
+++ b/sys/alpha/alpha/busdma_machdep.c
@@ -240,7 +240,7 @@ bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 
 	error = 0;
 
-	if (dmat->flags & BUS_DMA_ISA) {
+	if ((dmat->flags & BUS_DMA_ISA) && chipset.sgmap != NULL) {
 		bus_dmamap_t map;
 		map = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 					     M_NOWAIT);
@@ -290,10 +290,12 @@ bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 				panic("bus_dmamap_create: page reallocation "
 				      "not implemented");
 			}
-			pages = atop(dmat->maxsize);
+			pages = atop(dmat->maxsize) + 1;
 			pages = MIN(maxpages - total_bpages, pages);
-			error = alloc_bounce_pages(dmat, pages);
 
+			if (alloc_bounce_pages(dmat, pages) < pages)
+				error = ENOMEM;
+			
 			if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 				if (error == 0)
 					dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
@@ -316,7 +318,7 @@ bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 int
 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 {
-	if (dmat->flags & BUS_DMA_ISA) {
+	if ((dmat->flags & BUS_DMA_ISA) && chipset.sgmap != NULL) {
 		sgmap_free_region(chipset.sgmap, map->sgmaphandle);
 	}
 
@@ -404,7 +406,7 @@ bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 
 	error = 0;
 
-	if (dmat->flags & BUS_DMA_ISA) {
+	if ((dmat->flags & BUS_DMA_ISA) && chipset.sgmap != NULL) {
 		/*
 		 * For ISA dma, we use the chipset's scatter-gather
 		 * map to map the tranfer into the ISA reachable range
@@ -529,7 +531,7 @@ _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 {
 	struct bounce_page *bpage;
 
-	if (dmat->flags & BUS_DMA_ISA) {
+	if ((dmat->flags & BUS_DMA_ISA) && chipset.sgmap != NULL) {
 		sgmap_unload_region(chipset.sgmap,
 				    map->busaddress,
 				    map->buflen);
@@ -606,7 +608,7 @@ alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 							 M_NOWAIT, 0ul,
 							 dmat->lowaddr,
 							 PAGE_SIZE,
-							 0);
+							 dmat->boundary);
 		if (bpage->vaddr == NULL) {
 			free(bpage, M_DEVBUF);
 			break;
diff --git a/sys/alpha/alpha/vm_machdep.c b/sys/alpha/alpha/vm_machdep.c
index 68bbf29..8baea02 100644
--- a/sys/alpha/alpha/vm_machdep.c
+++ b/sys/alpha/alpha/vm_machdep.c
@@ -462,10 +462,8 @@ vm_page_zero_idle()
 void  
 swi_vm() 
 {     
-#if 0
 	if (busdma_swi_pending != 0)
 		busdma_swi();
-#endif
 }
 
 /*
diff --git a/sys/alpha/include/md_var.h b/sys/alpha/include/md_var.h
index 4595c8a..740d40b 100644
--- a/sys/alpha/include/md_var.h
+++ b/sys/alpha/include/md_var.h
@@ -37,6 +37,7 @@ extern	char	sigcode[];
 extern	char	esigcode[];
 extern	int	szsigcode;
 extern	int	Maxmem;
+extern	int	busdma_swi_pending;
 extern	void	(*netisrs[32]) __P((void));
 
 struct fpreg;
diff --git a/sys/alpha/isa/isa_dma.c b/sys/alpha/isa/isa_dma.c
index 8b5e64b..5864c7a 100644
--- a/sys/alpha/isa/isa_dma.c
+++ b/sys/alpha/isa/isa_dma.c
@@ -83,6 +83,7 @@ static bus_dmamap_t dma_map[8];
 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 u_int8_t dma_bounced = 0;
 
 #define VALID_DMA_MASK (7)
 
@@ -105,6 +106,7 @@ isa_dmainit(chan, bouncebufsize)
 		 * Reset the DMA hardware.
 		 */
 		outb(DMA1_RESET, 0);
+		outb((IO_DMA1 + 1*14), 0);
 		outb(DMA2_RESET, 0);
 		isa_dmacascade(4);
 	    
@@ -122,7 +124,7 @@ isa_dmainit(chan, bouncebufsize)
 	if (bus_dma_tag_create(/*parent*/NULL,
 			       /*alignment*/2,
 			       /*boundary*/boundary,
-			       /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
+			       /*lowaddr*/BUS_SPACE_MAXADDR_24BIT,
 			       /*highaddr*/BUS_SPACE_MAXADDR,
 			       /*filter*/NULL, /*filterarg*/NULL,
 			       /*maxsize*/bouncebufsize,
@@ -219,13 +221,15 @@ isa_dmacascade(chan)
  */
 
 struct isa_dmastart_arg {
-	int chan;
-	int flags;
+	caddr_t addr;
+	int 	chan;
+	int 	flags;
 };
 
 static void isa_dmastart_cb(void *arg, bus_dma_segment_t *segs, int nseg,
 			    int error)
 {
+	caddr_t addr = ((struct isa_dmastart_arg *) arg)->addr;
 	int chan = ((struct isa_dmastart_arg *) arg)->chan;
 	int flags = ((struct isa_dmastart_arg *) arg)->flags;
 	bus_addr_t phys = segs->ds_addr;
@@ -235,6 +239,17 @@ static void isa_dmastart_cb(void *arg, bus_dma_segment_t *segs, int nseg,
 	if (nseg != 1)
 		panic("isa_dmastart: transfer mapping not contiguous");
 
+	if ((chipset.sgmap == NULL) && 
+	    (pmap_extract(pmap_kernel(), (vm_offset_t)addr)
+		> BUS_SPACE_MAXADDR_24BIT)) { 
+		/* we bounced */
+		dma_bounced |= (1 << chan);
+                /* copy bounce buffer on write */
+                if (!(flags & ISADMA_READ)) 
+                        bus_dmamap_sync(dma_tag[chan], dma_map[chan], 
+			                  BUS_DMASYNC_PREWRITE);
+	}
+		
 	if ((chan & 4) == 0) {
 		/*
 		 * Program one of DMA channels 0..3.  These are
@@ -348,6 +363,7 @@ isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
 	 */
 	outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
 
+        args.addr = addr;
 	args.chan = chan;
 	args.flags = flags;
 	bus_dmamap_load(dma_tag[chan], dma_map[chan], addr, nbytes,
@@ -369,6 +385,15 @@ isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
 	    (dma_auto_mode & (1 << chan)) == 0 )
 		printf("isa_dmadone: channel %d not busy\n", chan);
 
+	if (dma_bounced & (1 << chan)) {
+		/* copy bounce buffer on read */
+		if (flags & ISADMA_READ) {
+			bus_dmamap_sync(dma_tag[chan], dma_map[chan],
+			                  BUS_DMASYNC_POSTREAD);
+		}
+		dma_bounced &= ~(1 << chan);
+	}
+
 	if ((dma_auto_mode & (1 << chan)) == 0) {
 		outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
 		bus_dmamap_unload(dma_tag[chan], dma_map[chan]);
diff --git a/sys/powerpc/aim/vm_machdep.c b/sys/powerpc/aim/vm_machdep.c
index 68bbf29..8baea02 100644
--- a/sys/powerpc/aim/vm_machdep.c
+++ b/sys/powerpc/aim/vm_machdep.c
@@ -462,10 +462,8 @@ vm_page_zero_idle()
 void  
 swi_vm() 
 {     
-#if 0
 	if (busdma_swi_pending != 0)
 		busdma_swi();
-#endif
 }
 
 /*
diff --git a/sys/powerpc/include/md_var.h b/sys/powerpc/include/md_var.h
index 4595c8a..740d40b 100644
--- a/sys/powerpc/include/md_var.h
+++ b/sys/powerpc/include/md_var.h
@@ -37,6 +37,7 @@ extern	char	sigcode[];
 extern	char	esigcode[];
 extern	int	szsigcode;
 extern	int	Maxmem;
+extern	int	busdma_swi_pending;
 extern	void	(*netisrs[32]) __P((void));
 
 struct fpreg;
diff --git a/sys/powerpc/powerpc/vm_machdep.c b/sys/powerpc/powerpc/vm_machdep.c
index 68bbf29..8baea02 100644
--- a/sys/powerpc/powerpc/vm_machdep.c
+++ b/sys/powerpc/powerpc/vm_machdep.c
@@ -462,10 +462,8 @@ vm_page_zero_idle()
 void  
 swi_vm() 
 {     
-#if 0
 	if (busdma_swi_pending != 0)
 		busdma_swi();
-#endif
 }
 
 /*