linux/arch/parisc
Helge Deller 48d27cb229 parisc: fix usage of 32bit PTE page table entries on 32bit kernels
This patch fixes a long outstanding bug on 32bit parisc linux kernels
which prevented us from using 32bit PTE table entries (instead of 64bit
entries of which 32bit were unused).

The problem was caused by this assembler statement in the L2_ptep
macro in arch/parisc/kernel/entry.S:447:
	EXTR \va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
which expanded to
	extrw,u r8,9,11,r1
and which has undefined behavior since the length value (11) extends
beyond the leftmost bit (11-1 > 9).
Interestingly PA2.0 processors seem to don't care and just zero-extend
the value, while PA1.1 processors don't.

Fix this problem by detecting an address space overflow with ASM_BITS_PER_PGD
and adjusting it accordingly. To prevent such problems in the future,
some compile time sanity checks in arch/parisc/mm/init.c were added.

Since the page table now only consumes half of it's old size, we can
use the freed memory to harmonize 32- and 64bit kernels and let both
map 16MB for the initial page table.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
2009-03-31 02:51:33 +00:00
..
configs parisc: update defconfigs 2009-03-13 01:33:34 -04:00
hpux parisc: remove unused local out_putf label 2009-03-13 01:17:59 -04:00
include/asm parisc: fix usage of 32bit PTE page table entries on 32bit kernels 2009-03-31 02:51:33 +00:00
kernel Merge branch 'linus' into percpu-cpumask-x86-for-linus-2 2009-03-28 04:26:01 +01:00
lib parisc: lib/: make code static 2009-01-05 18:15:24 +00:00
math-emu kbuild: fix up CFLAGS usage 2007-10-14 21:49:42 +02:00
mm parisc: fix usage of 32bit PTE page table entries on 32bit kernels 2009-03-31 02:51:33 +00:00
oprofile oprofile: more whitespace fixes 2008-10-15 20:55:51 +02:00
defpalo.conf
install.sh
Kconfig cpumask: centralize cpu_online_map and cpu_possible_map 2008-12-13 21:19:41 +10:30
Kconfig.debug alpha/parisc: remove config variable DEBUG_RWLOCK 2008-02-06 10:41:03 -08:00
Makefile parisc: quiet palo not-found message from "which" 2009-01-05 19:10:34 +00:00
nm