[src/trunk]: src/sys/arch/powerpc/include/oea Add TOPDOWN VM support.

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

details:   https://anonhg.NetBSD.org/src/rev/70609ef3f9e2
branches:  trunk
changeset: 543262:70609ef3f9e2
user:      matt <matt%NetBSD.org@localhost>
date:      Fri Feb 21 03:41:52 2003 +0000

description:
Add TOPDOWN VM support.

diffstat:

 sys/arch/powerpc/include/oea/vmparam.h |  11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diffs (21 lines):

diff -r 94860a2b50cb -r 70609ef3f9e2 sys/arch/powerpc/include/oea/vmparam.h
--- a/sys/arch/powerpc/include/oea/vmparam.h    Fri Feb 21 01:53:35 2003 +0000
+++ b/sys/arch/powerpc/include/oea/vmparam.h    Fri Feb 21 03:41:52 2003 +0000
@@ -151,6 +151,17 @@
 #define        VM_MIN_KERNEL_ADDRESS   ((vaddr_t) (KERNEL_SR << ADDR_SR_SHFT))
 #define        VM_MAX_KERNEL_ADDRESS   (VM_MIN_KERNEL_ADDRESS + 2*SEGMENT_LENGTH)
 
+/*
+ * The address to which unspecified mapping requests default
+ * Put the stack in it's own segment and start mmaping at the
+ * top of the next lower segment.
+ */
+#define        __HAVE_TOPDOWN_VM
+#ifdef USE_TOPDOWN_VM
+#define        VM_DEFAULT_ADDRESS(da, sz) \
+       (((VM_MAXUSER_ADDRESS - MAXSSIZ) & SEGMENT_MASK) - round_page(sz))
+#endif
+
 #ifndef VM_PHYSSEG_MAX
 #define        VM_PHYSSEG_MAX          16
 #endif