powerpc/mm: Tweak PTE bit combination definitions
This patch tweaks the way some PTE bit combinations are defined, in such a
way that the 32 and 64-bit variant become almost identical and that will
make it easier to bring in a new common pte-* file for the new variant
of the Book3-E support.
The combination of bits defining access to kernel pages are now clearly
separated from the combination used by userspace and the core VM. The
resulting generated code should remain identical unless I made a mistake.
Note: While at it, I removed a non-sensical statement related to CONFIG_KGDB
in ppc_mmu_32.c which could cause kernel mappings to be user accessible when
that option is enabled. Probably something that bitrot.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
index fe65c40..2d2a87e 100644
--- a/arch/powerpc/mm/ppc_mmu_32.c
+++ b/arch/powerpc/mm/ppc_mmu_32.c
@@ -74,9 +74,6 @@
unsigned long __init mmu_mapin_ram(void)
{
-#ifdef CONFIG_POWER4
- return 0;
-#else
unsigned long tot, bl, done;
unsigned long max_size = (256<<20);
@@ -95,7 +92,7 @@
break;
}
- setbat(2, PAGE_OFFSET, 0, bl, _PAGE_RAM);
+ setbat(2, PAGE_OFFSET, 0, bl, PAGE_KERNEL_X);
done = (unsigned long)bat_addrs[2].limit - PAGE_OFFSET + 1;
if ((done < tot) && !bat_addrs[3].limit) {
/* use BAT3 to cover a bit more */
@@ -103,12 +100,11 @@
for (bl = 128<<10; bl < max_size; bl <<= 1)
if (bl * 2 > tot)
break;
- setbat(3, PAGE_OFFSET+done, done, bl, _PAGE_RAM);
+ setbat(3, PAGE_OFFSET+done, done, bl, PAGE_KERNEL_X);
done = (unsigned long)bat_addrs[3].limit - PAGE_OFFSET + 1;
}
return done;
-#endif
}
/*
@@ -136,9 +132,7 @@
wimgxpp |= (flags & _PAGE_RW)? BPP_RW: BPP_RX;
bat[1].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */
bat[1].batl = BAT_PHYS_ADDR(phys) | wimgxpp;
-#ifndef CONFIG_KGDB /* want user access for breakpoints */
if (flags & _PAGE_USER)
-#endif
bat[1].batu |= 1; /* Vp = 1 */
if (flags & _PAGE_GUARDED) {
/* G bit must be zero in IBATs */