[POWERPC] Use 1TB segments

This makes the kernel use 1TB segments for all kernel mappings and for
user addresses of 1TB and above, on machines which support them
(currently POWER5+, POWER6 and PA6T).

We detect that the machine supports 1TB segments by looking at the
ibm,processor-segment-sizes property in the device tree.

We don't currently use 1TB segments for user addresses < 1T, since
that would effectively prevent 32-bit processes from using huge pages
unless we also had a way to revert to using 256MB segments.  That
would be possible but would involve extra complications (such as
keeping track of which segment size was used when HPTEs were inserted)
and is not addressed here.

Parts of this patch were originally written by Ben Herrenschmidt.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c
index de7e5ee451d2..3d64c81cc6e2 100644
--- a/arch/powerpc/platforms/cell/spufs/switch.c
+++ b/arch/powerpc/platforms/cell/spufs/switch.c
@@ -699,7 +699,7 @@ static inline void get_kernel_slb(u64 ea, u64 slb[2])
 		llp = mmu_psize_defs[mmu_linear_psize].sllp;
 	else
 		llp = mmu_psize_defs[mmu_virtual_psize].sllp;
-	slb[0] = (get_kernel_vsid(ea) << SLB_VSID_SHIFT) |
+	slb[0] = (get_kernel_vsid(ea, MMU_SEGSIZE_256M) << SLB_VSID_SHIFT) |
 		SLB_VSID_KERNEL | llp;
 	slb[1] = (ea & ESID_MASK) | SLB_ESID_V;
 }