4 files changed, 1192 insertions, 2 deletions

diff --git a/sys/amd64/amd64/busdma_machdep.c b/sys/amd64/amd64/busdma_machdep.c
new file mode 100644
index 000000000000..5f66ab929e1a
--- /dev/null
+++ b/sys/amd64/amd64/busdma_machdep.c
@@ -0,0 +1,585 @@
+/*
+ * Copyright (c) 1997 Justin T. Gibbs.
+ * All rights reserved.
+ *
+ * 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,
+ *    without modification, immediately at the beginning of the file.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *      $Id$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/queue.h>
+
+#include <vm/vm.h>
+#include <vm/vm_prot.h>
+#include <vm/vm_page.h>
+
+#include <machine/bus.h>
+#include <machine/md_var.h>
+
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+#define MAX_BPAGES 128
+
+struct bus_dma_tag {
+	bus_dma_tag_t	  parent;
+	bus_size_t	  boundary;
+	bus_addr_t	  lowaddr;
+	bus_addr_t	  highaddr;
+	bus_dma_filter_t *filter;
+	void		 *filterarg;
+	bus_size_t	  maxsize;
+	int		  nsegments;
+	bus_size_t	  maxsegsz;
+	int		  flags;
+	int		  ref_count;
+	int		  map_count;
+};
+
+struct bounce_page {
+	vm_offset_t	vaddr;		/* kva of bounce buffer */
+	bus_addr_t	busaddr;	/* Physical address */
+	vm_offset_t	datavaddr;	/* kva of client data */
+	bus_size_t	datacount;	/* client data count */
+	STAILQ_ENTRY(bounce_page) links;
+};
+
+int busdma_swi_pending;
+
+static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
+static int free_bpages;
+static int reserved_bpages;
+static int active_bpages;
+static int total_bpages;
+static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
+
+struct bus_dmamap {
+	struct bp_list	       bpages;
+	int		       pagesneeded;
+	int		       pagesreserved;
+	bus_dma_tag_t	       dmat;
+	void		      *buf;		/* unmapped buffer pointer */
+	bus_size_t	       buflen;		/* unmapped buffer length */
+	bus_dmamap_callback_t *callback;
+	void		      *callback_arg;
+	STAILQ_ENTRY(bus_dmamap) links;
+};
+
+static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
+static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
+static struct bus_dmamap nobounce_dmamap;
+
+static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
+static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map);
+static vm_offset_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
+				   vm_offset_t vaddr, bus_size_t size);
+static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
+static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
+
+static __inline int
+run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
+{
+	int retval;
+
+	retval = 0;
+	do {
+		if (paddr > dmat->lowaddr
+		 && paddr <= dmat->highaddr
+		 && (dmat->filter == NULL
+		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
+			retval = 1;
+
+		dmat = dmat->parent;		
+	} while (retval == 0 && dmat != NULL);
+	return (retval);
+}
+
+/*
+ * Allocate a device specific dma_tag.
+ */
+int
+bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t boundary,
+		   bus_addr_t lowaddr, bus_addr_t highaddr,
+		   bus_dma_filter_t *filter, void *filterarg,
+		   bus_size_t maxsize, int nsegments, bus_size_t maxsegsz,
+		   int flags, bus_dma_tag_t *dmat)
+{
+	bus_dma_tag_t newtag;
+	int error = 0;
+
+	/* Return a NULL tag on failure */
+	*dmat = NULL;
+
+	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
+	if (newtag == NULL)
+		return (ENOMEM);
+
+	newtag->parent = parent;
+	newtag->boundary = boundary;
+	newtag->lowaddr = trunc_page(lowaddr) + (PAGE_SIZE - 1);
+	newtag->highaddr = trunc_page(highaddr) + (PAGE_SIZE - 1);
+	newtag->filter = filter;
+	newtag->filterarg = filterarg;
+	newtag->maxsize = maxsize;
+	newtag->nsegments = nsegments;
+	newtag->maxsegsz = maxsegsz;
+	newtag->flags = flags;
+	newtag->ref_count = 1; /* Count ourself */
+	newtag->map_count = 0;
+	
+	/* Take into account any restrictions imposed by our parent tag */
+	if (parent != NULL) {
+		newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
+		newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
+		/*
+		 * XXX Not really correct??? Probably need to honor boundary
+		 *     all the way up the inheritence chain.
+		 */
+		newtag->boundary = MIN(parent->boundary, newtag->boundary);
+		if (newtag->filter == NULL) {
+			/*
+			 * Short circuit looking at our parent directly
+			 * since we have encapsulated all of it's information
+			 */
+			newtag->filter = parent->filter;
+			newtag->filterarg = parent->filterarg;
+			newtag->parent = parent->parent;
+		}
+		if (newtag->parent != NULL) {
+			parent->ref_count++;
+		}
+	}
+	
+	if (newtag->lowaddr < ptoa(Maxmem)) {
+		/* Must bounce */
+
+		if (lowaddr > bounce_lowaddr) {
+			/*
+			 * Go through the pool and kill any pages
+			 * that don't reside below lowaddr.
+			 */
+			panic("bus_dmamap_create: page reallocation "
+			      "not implemented");
+		}
+		if (ptoa(total_bpages) < maxsize) {
+			int pages;
+
+			pages = atop(maxsize) - total_bpages;
+
+			/* Add pages to our bounce pool */
+			if (alloc_bounce_pages(newtag, pages) < pages)
+				error = ENOMEM;
+		}
+	}
+	
+	if (error != 0) {
+		free(newtag, M_DEVBUF);
+	} else {
+		*dmat = newtag;
+	}
+	return (error);
+}
+
+int
+bus_dma_tag_destroy(bus_dma_tag_t dmat)
+{
+	if (dmat != NULL) {
+
+		if (dmat->map_count != 0)
+			return (EBUSY);
+
+		while (dmat != NULL) {
+			bus_dma_tag_t parent;
+
+			parent = dmat->parent;
+			dmat->ref_count--;
+			if (dmat->ref_count == 0) {
+				free(dmat, M_DEVBUF);
+			}
+			dmat = parent;
+		}
+	}
+	return (0);
+}
+
+/*
+ * Allocate a handle for mapping from kva/uva/physical
+ * address space into bus device space.
+ */
+int
+bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
+{
+	int error;
+
+	error = 0;
+
+	if (dmat->lowaddr < ptoa(Maxmem)) {
+		/* Must bounce */
+		int maxpages;
+
+		*mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
+					     M_NOWAIT);
+		if (*mapp == NULL) {
+			error = ENOMEM;
+		} else {
+			/* Initialize the new map */
+			bzero(*mapp, sizeof(**mapp));
+			STAILQ_INIT(&((*mapp)->bpages));
+		}
+		/*
+		 * Attempt to add pages to our pool on a per-instance
+		 * basis up to a sane limit.
+		 */
+		maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
+		if (dmat->map_count > 0
+		 && total_bpages < maxpages) {
+			int pages;
+
+			pages = atop(dmat->maxsize);
+			pages = MIN(maxpages - total_bpages, pages);
+			alloc_bounce_pages(dmat, pages);
+		}
+	} else {
+		*mapp = NULL;
+	}
+	if (error == 0)
+		dmat->map_count++;
+	return (error);
+}
+
+/*
+ * Destroy a handle for mapping from kva/uva/physical
+ * address space into bus device space.
+ */
+int
+bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
+{
+	if (map != NULL) {
+		if (STAILQ_FIRST(&map->bpages) != NULL)
+			return (EBUSY);
+		free(map, M_DEVBUF);
+	}
+	dmat->map_count--;
+	return (0);
+}
+
+#define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
+
+/*
+ * Map the buffer buf into bus space using the dmamap map.
+ */
+int
+bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
+		bus_size_t buflen, bus_dmamap_callback_t *callback,
+		void *callback_arg, int flags)
+{
+	vm_offset_t		vaddr;
+	vm_offset_t		paddr;
+#ifdef __GNUC__
+	bus_dma_segment_t	dm_segments[dmat->nsegments];
+#else
+	bus_dma_segment_t	dm_segments[BUS_DMAMAP_NSEGS];
+#endif
+	bus_dma_segment_t      *sg;
+	int			seg;
+	int			error;
+
+	error = 0;
+	/*
+	 * If we are being called during a callback, pagesneeded will
+	 * be non-zero, so we can avoid doing the work twice.
+	 */
+	if (dmat->lowaddr < ptoa(Maxmem) && map->pagesneeded == 0) {
+		vm_offset_t	vendaddr;
+
+		/*
+		 * Count the number of bounce pages
+		 * needed in order to complete this transfer
+		 */
+		vaddr = trunc_page(buf);
+		vendaddr = (vm_offset_t)buf + buflen;
+
+		while (vaddr < vendaddr) {
+			paddr = pmap_kextract(vaddr);
+			if (run_filter(dmat, paddr) != 0) {
+
+				map->pagesneeded++;
+			}
+			vaddr += PAGE_SIZE;
+		}
+	}
+
+	if (map == NULL)
+		map = &nobounce_dmamap;
+
+	/* Reserve Necessary Bounce Pages */
+	if (map->pagesneeded != 0) {
+		int s;
+
+		s = splhigh();
+	 	if (reserve_bounce_pages(dmat, map) != 0) {
+
+			/* Queue us for resources */
+			map->dmat = dmat;
+			map->buf = buf;
+			map->buflen = buflen;
+			map->callback = callback;
+			map->callback_arg = callback_arg;
+
+			STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
+			splx(s);
+
+			return (EINPROGRESS);
+		}
+		splx(s);
+	}
+
+	vaddr = (vm_offset_t)buf;
+	sg = &dm_segments[0];
+	seg = 1;
+	sg->ds_len = 0;
+
+	do {
+		bus_size_t	size;
+		vm_offset_t	nextpaddr;
+
+		paddr = pmap_kextract(vaddr);
+		size = PAGE_SIZE - (paddr & PAGE_MASK);
+		if (size > buflen)
+			size = buflen;
+
+		if (map->pagesneeded != 0
+		 && run_filter(dmat, paddr)) {
+			paddr = add_bounce_page(dmat, map, vaddr, size);
+		}
+
+		if (sg->ds_len == 0) {
+			sg->ds_addr = paddr;
+			sg->ds_len = size;
+		} else if (paddr == nextpaddr) {
+			sg->ds_len += size;
+		} else {
+			/* Go to the next segment */
+			sg++;
+			seg++;
+			if (seg > dmat->nsegments)
+				break;
+			sg->ds_addr = paddr;
+			sg->ds_len = size;
+		}
+		vaddr += size;
+		nextpaddr = paddr + size;
+		buflen -= size;
+	} while (buflen > 0);
+
+	if (buflen != 0) {
+		printf("bus_dmamap_load: Too many segs!\n");
+		error = EFBIG;
+	}
+
+	(*callback)(callback_arg, dm_segments, seg, error);
+
+	return (0);
+}
+
+/*
+ * Release the mapping held by map.
+ */
+void
+_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
+{
+	struct bounce_page *bpage;
+
+	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
+		STAILQ_REMOVE_HEAD(&map->bpages, links);
+		free_bounce_page(dmat, bpage);
+	}
+}
+
+void
+_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
+{
+	struct bounce_page *bpage;
+
+	if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
+		
+		/*
+		 * Handle data bouncing.  We might also
+		 * want to add support for invalidating
+		 * the caches on broken hardware
+		 */
+		switch (op) {
+		case BUS_DMASYNC_PREWRITE:
+			while (bpage != NULL) {
+				bcopy((void *)bpage->datavaddr,
+				      (void *)bpage->vaddr,
+				      bpage->datacount);
+				bpage = STAILQ_NEXT(bpage, links);
+			}
+			break;
+
+		case BUS_DMASYNC_POSTREAD:
+			while (bpage != NULL) {
+				bcopy((void *)bpage->vaddr,
+				      (void *)bpage->datavaddr,
+				      bpage->datacount);
+				bpage = STAILQ_NEXT(bpage, links);
+			}
+			break;
+		case BUS_DMASYNC_PREREAD:
+		case BUS_DMASYNC_POSTWRITE:
+			/* No-ops */
+			break;
+		}
+	}
+}
+
+static int
+alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
+{
+	int count;
+
+	count = 0;
+	if (total_bpages == 0) {
+		STAILQ_INIT(&bounce_page_list);
+		STAILQ_INIT(&bounce_map_waitinglist);
+		STAILQ_INIT(&bounce_map_callbacklist);
+	}
+	
+	while (numpages > 0) {
+		struct bounce_page *bpage;
+		int s;
+
+		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
+						     M_NOWAIT);
+
+		if (bpage == NULL)
+			break;
+		bzero(bpage, sizeof(*bpage));
+		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
+							 M_NOWAIT, 0ul,
+							 dmat->lowaddr,
+							 PAGE_SIZE, 0x10000);
+		if (bpage->vaddr == NULL) {
+			free(bpage, M_DEVBUF);
+			break;
+		}
+		bpage->busaddr = pmap_kextract(bpage->vaddr);
+		s = splhigh();
+		STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
+		total_bpages++;
+		free_bpages++;
+		splx(s);
+		count++;
+		numpages--;
+	}
+	return (count);
+}
+
+static int
+reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
+{
+	int pages;
+
+	pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
+	free_bpages -= pages;
+	reserved_bpages += pages;
+	map->pagesreserved += pages;
+	pages = map->pagesneeded - map->pagesreserved;
+
+	return (pages);
+}
+
+static vm_offset_t
+add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
+		bus_size_t size)
+{
+	int s;
+	struct bounce_page *bpage;
+
+	if (map->pagesneeded == 0)
+		panic("add_bounce_page: map doesn't need any pages");
+	map->pagesneeded--;
+
+	if (map->pagesreserved == 0)
+		panic("add_bounce_page: map doesn't need any pages");
+	map->pagesreserved--;
+
+	s = splhigh();
+	bpage = STAILQ_FIRST(&bounce_page_list);
+	if (bpage == NULL)
+		panic("add_bounce_page: free page list is empty");
+
+	STAILQ_REMOVE_HEAD(&bounce_page_list, links);
+	reserved_bpages--;
+	active_bpages++;
+	splx(s);
+
+	bpage->datavaddr = vaddr;
+	bpage->datacount = size;
+	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
+	return (bpage->busaddr);
+}
+
+static void
+free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
+{
+	int s;
+	struct bus_dmamap *map;
+
+	bpage->datavaddr = 0;
+	bpage->datacount = 0;
+
+	s = splhigh();
+	STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
+	free_bpages++;
+	active_bpages--;
+	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
+		if (reserve_bounce_pages(map->dmat, map) == 0) {
+			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
+			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
+					   map, links);
+			busdma_swi_pending = 1;
+			setsoftvm();
+		}
+	}
+	splx(s);
+}
+
+void
+busdma_swi()
+{
+	int s;
+	struct bus_dmamap *map;
+
+	s = splhigh();
+	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
+		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
+		splx(s);
+		bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
+				map->callback, map->callback_arg, /*flags*/0);
+		s = splhigh();
+	}
+	splx(s);
+}
diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c
index 0807026d56f8..0597ca48d299 100644
--- a/sys/amd64/amd64/vm_machdep.c
+++ b/sys/amd64/amd64/vm_machdep.c
@@ -38,7 +38,7 @@
  *
  *	from: @(#)vm_machdep.c	7.3 (Berkeley) 5/13/91
  *	Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
- *	$Id: vm_machdep.c,v 1.92 1997/11/20 19:41:20 bde Exp $
+ *	$Id: vm_machdep.c,v 1.93 1997/12/27 02:28:28 peter Exp $
  */
 
 #include "npx.h"
@@ -965,6 +965,16 @@ vm_page_zero_idle()
 }
 
 /*
+ * Software interrupt handler for queued VM system processing.
+ */   
+void  
+swi_vm() 
+{     
+	if (busdma_swi_pending != 0)
+		busdma_swi();
+}
+
+/*
  * Tell whether this address is in some physical memory region.
  * Currently used by the kernel coredump code in order to avoid
  * dumping the ``ISA memory hole'' which could cause indefinite hangs,
diff --git a/sys/i386/i386/busdma_machdep.c b/sys/i386/i386/busdma_machdep.c
new file mode 100644
index 000000000000..5f66ab929e1a
--- /dev/null
+++ b/sys/i386/i386/busdma_machdep.c
@@ -0,0 +1,585 @@
+/*
+ * Copyright (c) 1997 Justin T. Gibbs.
+ * All rights reserved.
+ *
+ * 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,
+ *    without modification, immediately at the beginning of the file.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *      $Id$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/queue.h>
+
+#include <vm/vm.h>
+#include <vm/vm_prot.h>
+#include <vm/vm_page.h>
+
+#include <machine/bus.h>
+#include <machine/md_var.h>
+
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+#define MAX_BPAGES 128
+
+struct bus_dma_tag {
+	bus_dma_tag_t	  parent;
+	bus_size_t	  boundary;
+	bus_addr_t	  lowaddr;
+	bus_addr_t	  highaddr;
+	bus_dma_filter_t *filter;
+	void		 *filterarg;
+	bus_size_t	  maxsize;
+	int		  nsegments;
+	bus_size_t	  maxsegsz;
+	int		  flags;
+	int		  ref_count;
+	int		  map_count;
+};
+
+struct bounce_page {
+	vm_offset_t	vaddr;		/* kva of bounce buffer */
+	bus_addr_t	busaddr;	/* Physical address */
+	vm_offset_t	datavaddr;	/* kva of client data */
+	bus_size_t	datacount;	/* client data count */
+	STAILQ_ENTRY(bounce_page) links;
+};
+
+int busdma_swi_pending;
+
+static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
+static int free_bpages;
+static int reserved_bpages;
+static int active_bpages;
+static int total_bpages;
+static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
+
+struct bus_dmamap {
+	struct bp_list	       bpages;
+	int		       pagesneeded;
+	int		       pagesreserved;
+	bus_dma_tag_t	       dmat;
+	void		      *buf;		/* unmapped buffer pointer */
+	bus_size_t	       buflen;		/* unmapped buffer length */
+	bus_dmamap_callback_t *callback;
+	void		      *callback_arg;
+	STAILQ_ENTRY(bus_dmamap) links;
+};
+
+static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
+static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
+static struct bus_dmamap nobounce_dmamap;
+
+static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
+static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map);
+static vm_offset_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
+				   vm_offset_t vaddr, bus_size_t size);
+static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
+static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
+
+static __inline int
+run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
+{
+	int retval;
+
+	retval = 0;
+	do {
+		if (paddr > dmat->lowaddr
+		 && paddr <= dmat->highaddr
+		 && (dmat->filter == NULL
+		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
+			retval = 1;
+
+		dmat = dmat->parent;		
+	} while (retval == 0 && dmat != NULL);
+	return (retval);
+}
+
+/*
+ * Allocate a device specific dma_tag.
+ */
+int
+bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t boundary,
+		   bus_addr_t lowaddr, bus_addr_t highaddr,
+		   bus_dma_filter_t *filter, void *filterarg,
+		   bus_size_t maxsize, int nsegments, bus_size_t maxsegsz,
+		   int flags, bus_dma_tag_t *dmat)
+{
+	bus_dma_tag_t newtag;
+	int error = 0;
+
+	/* Return a NULL tag on failure */
+	*dmat = NULL;
+
+	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
+	if (newtag == NULL)
+		return (ENOMEM);
+
+	newtag->parent = parent;
+	newtag->boundary = boundary;
+	newtag->lowaddr = trunc_page(lowaddr) + (PAGE_SIZE - 1);
+	newtag->highaddr = trunc_page(highaddr) + (PAGE_SIZE - 1);
+	newtag->filter = filter;
+	newtag->filterarg = filterarg;
+	newtag->maxsize = maxsize;
+	newtag->nsegments = nsegments;
+	newtag->maxsegsz = maxsegsz;
+	newtag->flags = flags;
+	newtag->ref_count = 1; /* Count ourself */
+	newtag->map_count = 0;
+	
+	/* Take into account any restrictions imposed by our parent tag */
+	if (parent != NULL) {
+		newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
+		newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
+		/*
+		 * XXX Not really correct??? Probably need to honor boundary
+		 *     all the way up the inheritence chain.
+		 */
+		newtag->boundary = MIN(parent->boundary, newtag->boundary);
+		if (newtag->filter == NULL) {
+			/*
+			 * Short circuit looking at our parent directly
+			 * since we have encapsulated all of it's information
+			 */
+			newtag->filter = parent->filter;
+			newtag->filterarg = parent->filterarg;
+			newtag->parent = parent->parent;
+		}
+		if (newtag->parent != NULL) {
+			parent->ref_count++;
+		}
+	}
+	
+	if (newtag->lowaddr < ptoa(Maxmem)) {
+		/* Must bounce */
+
+		if (lowaddr > bounce_lowaddr) {
+			/*
+			 * Go through the pool and kill any pages
+			 * that don't reside below lowaddr.
+			 */
+			panic("bus_dmamap_create: page reallocation "
+			      "not implemented");
+		}
+		if (ptoa(total_bpages) < maxsize) {
+			int pages;
+
+			pages = atop(maxsize) - total_bpages;
+
+			/* Add pages to our bounce pool */
+			if (alloc_bounce_pages(newtag, pages) < pages)
+				error = ENOMEM;
+		}
+	}
+	
+	if (error != 0) {
+		free(newtag, M_DEVBUF);
+	} else {
+		*dmat = newtag;
+	}
+	return (error);
+}
+
+int
+bus_dma_tag_destroy(bus_dma_tag_t dmat)
+{
+	if (dmat != NULL) {
+
+		if (dmat->map_count != 0)
+			return (EBUSY);
+
+		while (dmat != NULL) {
+			bus_dma_tag_t parent;
+
+			parent = dmat->parent;
+			dmat->ref_count--;
+			if (dmat->ref_count == 0) {
+				free(dmat, M_DEVBUF);
+			}
+			dmat = parent;
+		}
+	}
+	return (0);
+}
+
+/*
+ * Allocate a handle for mapping from kva/uva/physical
+ * address space into bus device space.
+ */
+int
+bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
+{
+	int error;
+
+	error = 0;
+
+	if (dmat->lowaddr < ptoa(Maxmem)) {
+		/* Must bounce */
+		int maxpages;
+
+		*mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
+					     M_NOWAIT);
+		if (*mapp == NULL) {
+			error = ENOMEM;
+		} else {
+			/* Initialize the new map */
+			bzero(*mapp, sizeof(**mapp));
+			STAILQ_INIT(&((*mapp)->bpages));
+		}
+		/*
+		 * Attempt to add pages to our pool on a per-instance
+		 * basis up to a sane limit.
+		 */
+		maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
+		if (dmat->map_count > 0
+		 && total_bpages < maxpages) {
+			int pages;
+
+			pages = atop(dmat->maxsize);
+			pages = MIN(maxpages - total_bpages, pages);
+			alloc_bounce_pages(dmat, pages);
+		}
+	} else {
+		*mapp = NULL;
+	}
+	if (error == 0)
+		dmat->map_count++;
+	return (error);
+}
+
+/*
+ * Destroy a handle for mapping from kva/uva/physical
+ * address space into bus device space.
+ */
+int
+bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
+{
+	if (map != NULL) {
+		if (STAILQ_FIRST(&map->bpages) != NULL)
+			return (EBUSY);
+		free(map, M_DEVBUF);
+	}
+	dmat->map_count--;
+	return (0);
+}
+
+#define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
+
+/*
+ * Map the buffer buf into bus space using the dmamap map.
+ */
+int
+bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
+		bus_size_t buflen, bus_dmamap_callback_t *callback,
+		void *callback_arg, int flags)
+{
+	vm_offset_t		vaddr;
+	vm_offset_t		paddr;
+#ifdef __GNUC__
+	bus_dma_segment_t	dm_segments[dmat->nsegments];
+#else
+	bus_dma_segment_t	dm_segments[BUS_DMAMAP_NSEGS];
+#endif
+	bus_dma_segment_t      *sg;
+	int			seg;
+	int			error;
+
+	error = 0;
+	/*
+	 * If we are being called during a callback, pagesneeded will
+	 * be non-zero, so we can avoid doing the work twice.
+	 */
+	if (dmat->lowaddr < ptoa(Maxmem) && map->pagesneeded == 0) {
+		vm_offset_t	vendaddr;
+
+		/*
+		 * Count the number of bounce pages
+		 * needed in order to complete this transfer
+		 */
+		vaddr = trunc_page(buf);
+		vendaddr = (vm_offset_t)buf + buflen;
+
+		while (vaddr < vendaddr) {
+			paddr = pmap_kextract(vaddr);
+			if (run_filter(dmat, paddr) != 0) {
+
+				map->pagesneeded++;
+			}
+			vaddr += PAGE_SIZE;
+		}
+	}
+
+	if (map == NULL)
+		map = &nobounce_dmamap;
+
+	/* Reserve Necessary Bounce Pages */
+	if (map->pagesneeded != 0) {
+		int s;
+
+		s = splhigh();
+	 	if (reserve_bounce_pages(dmat, map) != 0) {
+
+			/* Queue us for resources */
+			map->dmat = dmat;
+			map->buf = buf;
+			map->buflen = buflen;
+			map->callback = callback;
+			map->callback_arg = callback_arg;
+
+			STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
+			splx(s);
+
+			return (EINPROGRESS);
+		}
+		splx(s);
+	}
+
+	vaddr = (vm_offset_t)buf;
+	sg = &dm_segments[0];
+	seg = 1;
+	sg->ds_len = 0;
+
+	do {
+		bus_size_t	size;
+		vm_offset_t	nextpaddr;
+
+		paddr = pmap_kextract(vaddr);
+		size = PAGE_SIZE - (paddr & PAGE_MASK);
+		if (size > buflen)
+			size = buflen;
+
+		if (map->pagesneeded != 0
+		 && run_filter(dmat, paddr)) {
+			paddr = add_bounce_page(dmat, map, vaddr, size);
+		}
+
+		if (sg->ds_len == 0) {
+			sg->ds_addr = paddr;
+			sg->ds_len = size;
+		} else if (paddr == nextpaddr) {
+			sg->ds_len += size;
+		} else {
+			/* Go to the next segment */
+			sg++;
+			seg++;
+			if (seg > dmat->nsegments)
+				break;
+			sg->ds_addr = paddr;
+			sg->ds_len = size;
+		}
+		vaddr += size;
+		nextpaddr = paddr + size;
+		buflen -= size;
+	} while (buflen > 0);
+
+	if (buflen != 0) {
+		printf("bus_dmamap_load: Too many segs!\n");
+		error = EFBIG;
+	}
+
+	(*callback)(callback_arg, dm_segments, seg, error);
+
+	return (0);
+}
+
+/*
+ * Release the mapping held by map.
+ */
+void
+_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
+{
+	struct bounce_page *bpage;
+
+	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
+		STAILQ_REMOVE_HEAD(&map->bpages, links);
+		free_bounce_page(dmat, bpage);
+	}
+}
+
+void
+_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
+{
+	struct bounce_page *bpage;
+
+	if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
+		
+		/*
+		 * Handle data bouncing.  We might also
+		 * want to add support for invalidating
+		 * the caches on broken hardware
+		 */
+		switch (op) {
+		case BUS_DMASYNC_PREWRITE:
+			while (bpage != NULL) {
+				bcopy((void *)bpage->datavaddr,
+				      (void *)bpage->vaddr,
+				      bpage->datacount);
+				bpage = STAILQ_NEXT(bpage, links);
+			}
+			break;
+
+		case BUS_DMASYNC_POSTREAD:
+			while (bpage != NULL) {
+				bcopy((void *)bpage->vaddr,
+				      (void *)bpage->datavaddr,
+				      bpage->datacount);
+				bpage = STAILQ_NEXT(bpage, links);
+			}
+			break;
+		case BUS_DMASYNC_PREREAD:
+		case BUS_DMASYNC_POSTWRITE:
+			/* No-ops */
+			break;
+		}
+	}
+}
+
+static int
+alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
+{
+	int count;
+
+	count = 0;
+	if (total_bpages == 0) {
+		STAILQ_INIT(&bounce_page_list);
+		STAILQ_INIT(&bounce_map_waitinglist);
+		STAILQ_INIT(&bounce_map_callbacklist);
+	}
+	
+	while (numpages > 0) {
+		struct bounce_page *bpage;
+		int s;
+
+		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
+						     M_NOWAIT);
+
+		if (bpage == NULL)
+			break;
+		bzero(bpage, sizeof(*bpage));
+		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
+							 M_NOWAIT, 0ul,
+							 dmat->lowaddr,
+							 PAGE_SIZE, 0x10000);
+		if (bpage->vaddr == NULL) {
+			free(bpage, M_DEVBUF);
+			break;
+		}
+		bpage->busaddr = pmap_kextract(bpage->vaddr);
+		s = splhigh();
+		STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
+		total_bpages++;
+		free_bpages++;
+		splx(s);
+		count++;
+		numpages--;
+	}
+	return (count);
+}
+
+static int
+reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
+{
+	int pages;
+
+	pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
+	free_bpages -= pages;
+	reserved_bpages += pages;
+	map->pagesreserved += pages;
+	pages = map->pagesneeded - map->pagesreserved;
+
+	return (pages);
+}
+
+static vm_offset_t
+add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
+		bus_size_t size)
+{
+	int s;
+	struct bounce_page *bpage;
+
+	if (map->pagesneeded == 0)
+		panic("add_bounce_page: map doesn't need any pages");
+	map->pagesneeded--;
+
+	if (map->pagesreserved == 0)
+		panic("add_bounce_page: map doesn't need any pages");
+	map->pagesreserved--;
+
+	s = splhigh();
+	bpage = STAILQ_FIRST(&bounce_page_list);
+	if (bpage == NULL)
+		panic("add_bounce_page: free page list is empty");
+
+	STAILQ_REMOVE_HEAD(&bounce_page_list, links);
+	reserved_bpages--;
+	active_bpages++;
+	splx(s);
+
+	bpage->datavaddr = vaddr;
+	bpage->datacount = size;
+	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
+	return (bpage->busaddr);
+}
+
+static void
+free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
+{
+	int s;
+	struct bus_dmamap *map;
+
+	bpage->datavaddr = 0;
+	bpage->datacount = 0;
+
+	s = splhigh();
+	STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
+	free_bpages++;
+	active_bpages--;
+	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
+		if (reserve_bounce_pages(map->dmat, map) == 0) {
+			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
+			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
+					   map, links);
+			busdma_swi_pending = 1;
+			setsoftvm();
+		}
+	}
+	splx(s);
+}
+
+void
+busdma_swi()
+{
+	int s;
+	struct bus_dmamap *map;
+
+	s = splhigh();
+	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
+		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
+		splx(s);
+		bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
+				map->callback, map->callback_arg, /*flags*/0);
+		s = splhigh();
+	}
+	splx(s);
+}
diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c
index 0807026d56f8..0597ca48d299 100644
--- a/sys/i386/i386/vm_machdep.c
+++ b/sys/i386/i386/vm_machdep.c
@@ -38,7 +38,7 @@
  *
  *	from: @(#)vm_machdep.c	7.3 (Berkeley) 5/13/91
  *	Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
- *	$Id: vm_machdep.c,v 1.92 1997/11/20 19:41:20 bde Exp $
+ *	$Id: vm_machdep.c,v 1.93 1997/12/27 02:28:28 peter Exp $
  */
 
 #include "npx.h"
@@ -965,6 +965,16 @@ vm_page_zero_idle()
 }
 
 /*
+ * Software interrupt handler for queued VM system processing.
+ */   
+void  
+swi_vm() 
+{     
+	if (busdma_swi_pending != 0)
+		busdma_swi();
+}
+
+/*
  * Tell whether this address is in some physical memory region.
  * Currently used by the kernel coredump code in order to avoid
  * dumping the ``ISA memory hole'' which could cause indefinite hangs,