Add an alignment argument to uvm_map that specifies an alignment hint

for the virtual address.

1 files changed, 61 insertions, 23 deletions

diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index b754d9ccde4..d3d00972295 100644
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,5 +1,5 @@
-/*	$OpenBSD: uvm_map.c,v 1.27 2001/11/06 13:36:52 art Exp $	*/
-/*	$NetBSD: uvm_map.c,v 1.80 2000/08/01 00:53:11 wiz Exp $	*/
+/*	$OpenBSD: uvm_map.c,v 1.28 2001/11/07 01:18:01 art Exp $	*/
+/*	$NetBSD: uvm_map.c,v 1.81 2000/09/13 15:00:25 thorpej Exp $	*/
 
 /* 
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -456,16 +456,23 @@ uvm_map_clip_end(map, entry, end)
  *    case [4] is for kernel mappings where we don't know the offset until
  *    we've found a virtual address.   note that kernel object offsets are
  *    always relative to vm_map_min(kernel_map).
+ *
+ * => if `align' is non-zero, we try to align the virtual address to
+ *	the specified alignment.  this is only a hint; if we can't
+ *	do it, the address will be unaligned.  this is provided as
+ *	a mechanism for large pages.
+ *
  * => XXXCDC: need way to map in external amap?
  */
 
 int
-uvm_map(map, startp, size, uobj, uoffset, flags)
+uvm_map(map, startp, size, uobj, uoffset, align, flags)
 	vm_map_t map;
 	vaddr_t *startp;	/* IN/OUT */
 	vsize_t size;
 	struct uvm_object *uobj;
 	voff_t uoffset;
+	vsize_t align;
 	uvm_flag_t flags;
 {
 	vm_map_entry_t prev_entry, new_entry;
@@ -500,7 +507,7 @@ uvm_map(map, startp, size, uobj, uoffset, flags)
 		vm_map_lock(map); /* could sleep here */
 	}
 	if ((prev_entry = uvm_map_findspace(map, *startp, size, startp, 
-	    uobj, uoffset, flags & UVM_FLAG_FIXED)) == NULL) {
+	    uobj, uoffset, align, flags)) == NULL) {
 		UVMHIST_LOG(maphist,"<- uvm_map_findspace failed!",0,0,0,0);
 		vm_map_unlock(map);
 		return (KERN_NO_SPACE);
@@ -775,39 +782,54 @@ uvm_map_lookup_entry(map, address, entry)
 	return (FALSE);
 }
 
-
 /*
  * uvm_map_findspace: find "length" sized space in "map".
  *
- * => "hint" is a hint about where we want it, unless fixed is true
- *	(in which case we insist on using "hint").
+ * => "hint" is a hint about where we want it, unless FINDSPACE_FIXED is
+ *	set (in which case we insist on using "hint").
  * => "result" is VA returned
  * => uobj/uoffset are to be used to handle VAC alignment, if required
+ * => if `align' is non-zero, we attempt to align to that value.
  * => caller must at least have read-locked map
  * => returns NULL on failure, or pointer to prev. map entry if success
  * => note this is a cross between the old vm_map_findspace and vm_map_find
  */
 
 vm_map_entry_t
-uvm_map_findspace(map, hint, length, result, uobj, uoffset, fixed)
+uvm_map_findspace(map, hint, length, result, uobj, uoffset, align, flags)
 	vm_map_t map;
 	vaddr_t hint;
 	vsize_t length;
 	vaddr_t *result; /* OUT */
 	struct uvm_object *uobj;
 	voff_t uoffset;
-	boolean_t fixed;
+	vsize_t align;
+	int flags;
 {
 	vm_map_entry_t entry, next, tmp;
-	vaddr_t end;
+	vaddr_t end, orig_hint;
 	UVMHIST_FUNC("uvm_map_findspace");
 	UVMHIST_CALLED(maphist);
 
-	UVMHIST_LOG(maphist, "(map=0x%x, hint=0x%x, len=%d, fixed=%d)", 
-		map, hint, length, fixed);
+	UVMHIST_LOG(maphist, "(map=0x%x, hint=0x%x, len=%d, flags=0x%x)", 
+		map, hint, length, flags);
+
+#ifdef DIAGNOSTIC
+	if ((align & (align - 1)) != 0)
+		panic("uvm_map_findspace: alignment not power of 2");
+	if ((flags & UVM_FLAG_FIXED) != 0 && align != 0)
+		panic("uvm_map_findslace: fixed and alignment both specified");
+#endif
+
+	/*
+	 * remember the original hint.  if we are aligning, then we
+	 * may have to try again with no alignment constraint if
+	 * we fail the first time.
+	 */
+	orig_hint = hint;
 
 	if (hint < map->min_offset) {	/* check ranges ... */
-		if (fixed) {
+		if (flags & UVM_FLAG_FIXED) {
 			UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0);
 			return(NULL);
 		}
@@ -824,13 +846,13 @@ uvm_map_findspace(map, hint, length, result, uobj, uoffset, fixed)
 	 * something at this address, we have to start after it.
 	 */
 
-	if (!fixed && hint == map->min_offset) {
+	if ((flags & UVM_FLAG_FIXED) == 0 && hint == map->min_offset) {
 		if ((entry = map->first_free) != &map->header) 
 			hint = entry->end;
 	} else {
 		if (uvm_map_lookup_entry(map, hint, &tmp)) {
 			/* "hint" address already in use ... */
-			if (fixed) {
+			if (flags & UVM_FLAG_FIXED) {
 				UVMHIST_LOG(maphist,"<- fixed & VA in use",
 				    0, 0, 0, 0);
 				return(NULL);
@@ -860,18 +882,33 @@ uvm_map_findspace(map, hint, length, result, uobj, uoffset, fixed)
 		 * push hint forward as needed to avoid VAC alias problems.
 		 * we only do this if a valid offset is specified.
 		 */
-		if (!fixed && uoffset != UVM_UNKNOWN_OFFSET)
-		  PMAP_PREFER(uoffset, &hint);
+		if ((flags & UVM_FLAG_FIXED) == 0 &&
+		    uoffset != UVM_UNKNOWN_OFFSET)
+			PMAP_PREFER(uoffset, &hint);
 #endif
+		if (align != 0) {
+			if ((hint & (align - 1)) != 0)
+				hint = roundup(hint, align);
+			/*
+			 * XXX Should we PMAP_PREFER() here again?
+			 */
+		}
 		end = hint + length;
 		if (end > map->max_offset || end < hint) {
 			UVMHIST_LOG(maphist,"<- failed (off end)", 0,0,0,0);
+			if (align != 0) {
+				UVMHIST_LOG(maphist,
+				    "calling recursively, no align",
+				    0,0,0,0);
+				return (uvm_map_findspace(map, orig_hint,
+				    length, result, uobj, uoffset, 0, flags));
+			}
 			return (NULL);
 		}
 		next = entry->next;
 		if (next == &map->header || next->start >= end)
 			break;
-		if (fixed) {
+		if (flags & UVM_FLAG_FIXED) {
 			UVMHIST_LOG(maphist,"<- fixed mapping failed", 0,0,0,0);
 			return(NULL); /* only one shot at it ... */
 		}
@@ -961,7 +998,7 @@ uvm_unmap_remove(map, start, end, entry_list)
 		UVM_MAP_CLIP_END(map, entry, end); 
 		next = entry->next;
 		len = entry->end - entry->start;
-	
+
 		/*
 		 * unwire before removing addresses from the pmap; otherwise
 		 * unwiring will put the entries back into the pmap (XXX).
@@ -1156,10 +1193,11 @@ uvm_unmap_detach(first_entry, amap_unref_flags)
  */
 
 int
-uvm_map_reserve(map, size, offset, raddr)
+uvm_map_reserve(map, size, offset, align, raddr)
 	vm_map_t map;
 	vsize_t size;
-	vaddr_t offset;    /* hint for pmap_prefer */
+	vaddr_t offset;	/* hint for pmap_prefer */
+	vsize_t align;	/* alignment hint */
 	vaddr_t *raddr;	/* IN:hint, OUT: reserved VA */
 {
 	UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist); 
@@ -1175,7 +1213,7 @@ uvm_map_reserve(map, size, offset, raddr)
 	 * reserve some virtual space.
 	 */
  
-	if (uvm_map(map, raddr, size, NULL, offset,
+	if (uvm_map(map, raddr, size, NULL, offset, 0,
 	    UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE,
 	    UVM_ADV_RANDOM, UVM_FLAG_NOMERGE)) != KERN_SUCCESS) {
 	    UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0);
@@ -1353,7 +1391,7 @@ uvm_map_extract(srcmap, start, len, dstmap, dstaddrp, flags)
 	 */
 
 	dstaddr = vm_map_min(dstmap);
-	if (uvm_map_reserve(dstmap, len, start, &dstaddr) == FALSE)
+	if (uvm_map_reserve(dstmap, len, start, 0, &dstaddr) == FALSE)
 		return(ENOMEM);
 	*dstaddrp = dstaddr;	/* pass address back to caller */
 	UVMHIST_LOG(maphist, "  dstaddr=0x%x", dstaddr,0,0,0);