Some (if not all) G5 systems use a different layout for the physical memory

information (property `reg' of the `/memory' node). Fortunately the available
physical memory information still uses the same format, so this only affects
the computation of physmem.

Detect this case and parse the information correctly, converting to the format
expected by pmap, ignoring physical memory beyond 4GB.

Compute physmem from all the physical memory information, even memory not
usable by the kernel. Let pmap not recompute physmem in pmap_bootstrap() if
physmem is != 0 upon entry.

This should allow G5 systems fitted with more than 2GB of physical memory to
report the correct amount of memory, even though the kernel will only use
the lower 2GB.

Prompted by a dmesg@ submission by Greg Marsh, owner of a 3.5GB G5

help and tweaks kettenis@, ok mpi@

1 files changed, 7 insertions, 3 deletions

diff --git a/sys/arch/powerpc/powerpc/pmap.c b/sys/arch/powerpc/powerpc/pmap.c
index 896b749e4cc..e6a84ac7bff 100644
--- a/sys/arch/powerpc/powerpc/pmap.c
+++ b/sys/arch/powerpc/powerpc/pmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.c,v 1.122 2013/12/29 19:09:21 brad Exp $ */
+/*	$OpenBSD: pmap.c,v 1.123 2014/02/08 13:17:40 miod Exp $ */
 
 /*
  * Copyright (c) 2001, 2002, 2007 Dale Rahn.
@@ -1396,18 +1396,22 @@ void
 pmap_avail_setup(void)
 {
 	struct mem_region *mp;
+	int pmap_physmem;
 
 	(fw->mem_regions) (&pmap_mem, &pmap_avail);
 	pmap_cnt_avail = 0;
-	physmem = 0;
+	pmap_physmem = 0;
 
 	ndumpmem = 0;
 	for (mp = pmap_mem; mp->size !=0; mp++, ndumpmem++) {
-		physmem += atop(mp->size);
+		pmap_physmem += atop(mp->size);
 		dumpmem[ndumpmem].start = atop(mp->start);
 		dumpmem[ndumpmem].end = atop(mp->start + mp->size);
 	}
 
+	if (physmem == 0)
+		physmem = pmap_physmem;
+
 	for (mp = pmap_avail; mp->size !=0 ; mp++) {
 		if (physmaxaddr <  mp->start + mp->size)
 			physmaxaddr = mp->start + mp->size;