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[PATCH] powerpc: Separate usage of KERNELBASE and PAGE_OFFSET

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This patch separates usage of KERNELBASE and PAGE_OFFSET. I haven't
looked at any of the PPC32 code, if we ever want to support Kdump on
PPC we'll have to do another audit, ditto for iSeries.

This patch makes PAGE_OFFSET the constant, it'll always be 0xC * 1
gazillion for 64-bit.

To get a physical address from a virtual one you subtract PAGE_OFFSET,
_not_ KERNELBASE.

KERNELBASE is the virtual address of the start of the kernel, it's
often the same as PAGE_OFFSET, but _might not be_.

If you want to know something's offset from the start of the kernel
you should subtract KERNELBASE.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Michael Ellerman
2005-12-05 10:24:33 -06:00
committed by Paul Mackerras
parent 51fae6de24
commit b5666f7039
9 changed files with 37 additions and 24 deletions
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10
arch/powerpc/mm/stab.c
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@@ -40,7 +40,7 @@ static int make_ste(unsigned long stab, unsigned long esid, unsigned long vsid)
unsigned long entry, group, old_esid, castout_entry, i;
unsigned int global_entry;
struct stab_entry *ste, *castout_ste;
unsigned long kernel_segment = (esid << SID_SHIFT) >= KERNELBASE;
unsigned long kernel_segment = (esid << SID_SHIFT) >= PAGE_OFFSET;
vsid_data = vsid << STE_VSID_SHIFT;
esid_data = esid << SID_SHIFT | STE_ESID_KP | STE_ESID_V;
@@ -83,7 +83,7 @@ static int make_ste(unsigned long stab, unsigned long esid, unsigned long vsid)
}
/* Dont cast out the first kernel segment */
if ((castout_ste->esid_data & ESID_MASK) != KERNELBASE)
if ((castout_ste->esid_data & ESID_MASK) != PAGE_OFFSET)
break;
castout_entry = (castout_entry + 1) & 0xf;
@@ -251,7 +251,7 @@ void stabs_alloc(void)
panic("Unable to allocate segment table for CPU %d.\n",
cpu);
newstab += KERNELBASE;
newstab = (unsigned long)__va(newstab);
memset((void *)newstab, 0, HW_PAGE_SIZE);
@@ -270,11 +270,11 @@ void stabs_alloc(void)
*/
void stab_initialize(unsigned long stab)
{
unsigned long vsid = get_kernel_vsid(KERNELBASE);
unsigned long vsid = get_kernel_vsid(PAGE_OFFSET);
unsigned long stabreal;
asm volatile("isync; slbia; isync":::"memory");
make_ste(stab, GET_ESID(KERNELBASE), vsid);
make_ste(stab, GET_ESID(PAGE_OFFSET), vsid);
/* Order update */
asm volatile("sync":::"memory");