commit 058ddee5625ade9e9e011b9ae155ac3b8d4eda3a
author Russell King <rmk@dyn-67.arm.linux.org.uk> Thu Aug 07 22:36:59 2008 +0100
committer Russell King <rmk+kernel@arm.linux.org.uk> Thu Aug 07 22:36:59 2008 +0100
tree 2821d666c06733da81f606624bf2a16bdf86ce73
parent afd2fc02ab7bae6062671c5ca80dd34c34a63fb7

[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>