improved handling of mapping of devices who's registers do not reside on

page boundaries:
 - change bus_tmp() to include the offset from the start of page in the
	returned KVA [rather than forcing each driver to add it back in
	individually]
 - changed bus_map() to include the offset from the start of page in the
	the returned value if a mapping is found in the PROM's KVA area
 - clarified a few comments

diff --git a/sys/arch/sparc/dev/obio.c b/sys/arch/sparc/dev/obio.c
index 858c729..f78bbcc 100644 (file)
--- a/sys/arch/sparc/dev/obio.c
+++ b/sys/arch/sparc/dev/obio.c
@@ -163,13 +163,15 @@ busattach(parent, child, args, bustype)
                return (0);
 
        /*
-        * check if XXmatch() replaced the temporary
-        * mapping with a real mapping.
+        * check if XXmatch() replaced the temporary mapping with 
+        * a real mapping.  If not, then make sure we don't pass the
+        * tmp mapping to the attach routine.
         */
-       if (tmp == oca.ca_ra.ra_vaddr)
-               oca.ca_ra.ra_vaddr = NULL;
+       if (oca.ca_ra.ra_vaddr == tmp)
+               oca.ca_ra.ra_vaddr = NULL; /* wipe out tmp address */
        /*
-        * or if it has asked us to create a mapping..
+        * the match routine will set "ra_len" if it wants us to 
+        * establish a mapping for it.
         * (which won't be seen on future XXmatch calls,
         * so not as useful as it seems.)
         */
@@ -368,7 +370,8 @@ bus_map(pa, len, bustype)
                        pte = getpte(va);
                        if ((pte & PG_V) != 0 && (pte & PG_TYPE) == pgtype &&
                            (pte & PG_PFNUM) == pf)
-                               return ((void *)va);
+                               return ((void *)(va | ((u_long)pa & PGOFSET)));
+                                       /* note: preserve page offset */
                }
        }
        rr.rr_paddr = pa;
@@ -386,7 +389,7 @@ bus_tmp(pa, bustype)
        pmap_enter(pmap_kernel(), TMPMAP_VA,
            addr | pmtype | PMAP_NC,
            VM_PROT_READ | VM_PROT_WRITE, 1);
-       return ((void *)TMPMAP_VA);
+       return ((void *)(TMPMAP_VA | ((u_long) pa & PGOFSET)) );
 }
 
 void