[ARM] Fix SMP booting with non-zero PHYS_OFFSET
The existing code tries to get the pmd for the temporary page table
by doing:
pgd = pgd_alloc(&init_mm);
pmd = pmd_offset(pgd, PHYS_OFFSET);
Since we have a two level page table, pmd_offset() is a no-op, so
this just has a casting effect from a pgd to a pmd - the address
argument is unused. So this can't work.
Normally, we'd do:
pgd = pgd_offset(&init_mm, PHYS_OFFSET);
...
pmd = pmd_offset(pgd, PHYS_OFFSET);
to get the pmd you want. However, pgd_offset() takes the mm_struct,
not the (unattached) pgd we just allocated. So, instead use:
pgd = pgd_alloc(&init_mm);
pmd = pmd_offset(pgd + pgd_index(PHYS_OFFSET), PHYS_OFFSET);
Reported-by: Antti P Miettinen <ananaza@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 5a7c095..e9842f6 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -100,7 +100,7 @@
* a 1:1 mapping for the physical address of the kernel.
*/
pgd = pgd_alloc(&init_mm);
- pmd = pmd_offset(pgd, PHYS_OFFSET);
+ pmd = pmd_offset(pgd + pgd_index(PHYS_OFFSET), PHYS_OFFSET);
*pmd = __pmd((PHYS_OFFSET & PGDIR_MASK) |
PMD_TYPE_SECT | PMD_SECT_AP_WRITE);
@@ -139,7 +139,7 @@
secondary_data.stack = NULL;
secondary_data.pgdir = 0;
- *pmd_offset(pgd, PHYS_OFFSET) = __pmd(0);
+ *pmd = __pmd(0);
pgd_free(&init_mm, pgd);
if (ret) {