[src/trunk]: src/sys/arch/sparc/sparc sun4_dmamap_load(): Check if boundary c...

[pk <pk%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/196b84f4f69f
branches:  trunk
changeset: 503010:196b84f4f69f
user:      pk <pk%NetBSD.org@localhost>
date:      Sun Jan 28 20:48:31 2001 +0000

description:
sun4_dmamap_load(): Check if boundary condition can be satisfied instead
of panicing blindly.

diffstat:

 sys/arch/sparc/sparc/machdep.c |  22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)

diffs (43 lines):

diff -r 0eedad3ffd64 -r 196b84f4f69f sys/arch/sparc/sparc/machdep.c
--- a/sys/arch/sparc/sparc/machdep.c    Sun Jan 28 20:47:45 2001 +0000
+++ b/sys/arch/sparc/sparc/machdep.c    Sun Jan 28 20:48:31 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: machdep.c,v 1.173 2001/01/20 13:44:30 pk Exp $ */
+/*     $NetBSD: machdep.c,v 1.174 2001/01/28 20:48:31 pk Exp $ */
 
 /*-
  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
@@ -1393,8 +1393,23 @@
                /*
                 * XXX Need to implement "don't dma across this boundry".
                 */
-               if (map->_dm_boundary != 0)
-                       panic("bus_dmamap_load: boundaries not implemented");
+               if (map->_dm_boundary != 0) {
+                       bus_addr_t baddr;
+
+                       /* Calculate first boundary line after `buf' */
+                       baddr = ((bus_addr_t)va + map->_dm_boundary) &
+                                       -map->_dm_boundary;
+
+                       /*
+                        * If the requested segment crosses the boundary,
+                        * we can't grant a direct map. For now, steal some
+                        * space from the `24BIT' map instead.
+                        *
+                        * (XXX - no overflow detection here)
+                        */
+                       if (buflen > (baddr - (bus_addr_t)va))
+                               goto no_fit;
+               }
                map->dm_mapsize = buflen;
                map->dm_nsegs = 1;
                map->dm_segs[0].ds_addr = (bus_addr_t)va;
@@ -1403,6 +1418,7 @@
                return (0);
        }
 
+no_fit:
        sgsize = round_page(buflen + (va & (pagesz - 1)));
 
        if (extent_alloc(dvmamap24, sgsize, pagesz, map->_dm_boundary,