From 12670395dc3e6a486246ece6d68884c1cf249ae4 Mon Sep 17 00:00:00 2001
From: ache <ache@FreeBSD.org>
Date: Tue, 29 Sep 1998 22:06:33 +0000
Subject: [PATCH] vm86_datacall: always use workaround since temp. malloced
 buffer or stack area can be passed (and mapped to page1!) as vesa.c does. Use
 contigmalloc now to get proper alignment. Bump max buffer size to PAGE_SIZE

---
 sys/i386/i386/vm86.c | 40 ++++++++++++++++++----------------------
 1 file changed, 18 insertions(+), 22 deletions(-)

diff --git a/sys/i386/i386/vm86.c b/sys/i386/i386/vm86.c
index 25da03aee658..eef835b18866 100644
--- a/sys/i386/i386/vm86.c
+++ b/sys/i386/i386/vm86.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: vm86.c,v 1.16 1998/09/29 09:06:00 bde Exp $
+ *	$Id: vm86.c,v 1.17 1998/09/29 20:36:31 ache Exp $
  */
 
 #include "opt_vm86.h"
@@ -32,6 +32,7 @@
 #include <sys/systm.h>
 #include <sys/proc.h>
 #include <sys/lock.h>
+#include <sys/malloc.h>
 
 #include <vm/vm.h>
 #include <vm/vm_prot.h>
@@ -626,35 +627,30 @@ vm86_datacall(intnum, vmf, buffer, buflen, segment, offset)
 	int buflen;
 	u_short *segment, *offset;
 {
-	int ret, internb;
+	int ret;
 	u_int page;
-	u_short off;
-#define MAX_DATA_SIZE 1024
-	static u_char mapped_to_page1[MAX_DATA_SIZE * 2];
 	static u_char *buf;
 
-	if (buflen < 0 || buflen > MAX_DATA_SIZE)
+	if (buflen < 0 || buflen > PAGE_SIZE)
 		return(-1);
-        page = (u_int)buffer & PG_FRAME;
-        *offset = (u_int)buffer & PAGE_MASK;
-	if ((*offset + buflen) & PG_FRAME) {
-		if (buf == NULL) {
-			buf = mapped_to_page1;
-			off = (u_int)buf & PAGE_MASK;
-			if ((off + MAX_DATA_SIZE) & PG_FRAME)
-				buf += PAGE_SIZE - off;
-		}
-		page = (u_int)buf & PG_FRAME;
-		bcopy((void *)buffer, (void *)buf, (size_t)buflen);
-		internb = 1;
-	} else
-		internb = 0;
+
+	if (buf == NULL) {
+		buf = (u_char *)contigmalloc(PAGE_SIZE, M_DEVBUF, M_WAITOK,
+					     0ul, ~0ul, PAGE_SIZE, 0);
+		if (buf == NULL)
+			return(-1);
+	}
+
+	*offset = 0;
 	*segment = 0x100;
+
+	bcopy((void *)buffer, (void *)buf, (size_t)buflen);
+	page = (u_int)buf & PG_FRAME;
 	page = vtophys(page);
 	vmf->vmf_trapno = page | (intnum & PAGE_MASK);
 	ret = vm86_bioscall(vmf);
-	if (internb)
-		bcopy((void *)buf, (void *)buffer, (size_t)buflen);
+	bcopy((void *)buf, (void *)buffer, (size_t)buflen);
+
 	return ret;
 }