tree 8467dab77d8b66423f65612d878aef3efb1056ca
parent ac73fddfc523bf3c3525d16356b44527c44fae6d
author David Gibson <david@gibson.dropbear.id.au> 1265659743 +0000
committer Benjamin Herrenschmidt <benh@kernel.crashing.org> 1265770686 +1100

powerpc: Fix address masking bug in hpte_need_flush()

Commit f71dc176aa06359681c30ba6877ffccab6fba3a6 'Make
hpte_need_flush() correctly mask for multiple page sizes' introduced
bug, which is triggered when a kernel with a 64k base page size is run
on a system whose hardware does not 64k hash PTEs.  In this case, we
emulate 64k pages with multiple 4k hash PTEs, however in
hpte_need_flush() we incorrectly only mask the hardware page size from
the address, instead of the logical page size.  This causes things to
go wrong when we later attempt to iterate through the hardware
subpages of the logical page.

This patch corrects the error.  It has been tested on pSeries bare
metal by Michael Neuling.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>