Re: [PATCH v2 7/8] powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for relocatable kernel

On Sun, 2013-08-04 at 08:50 +0800, Kevin Hao wrote:

On Fri, Jul 26, 2013 at 07:17:57PM -0500, Scott Wood wrote:

quoted

quoted

diff --git a/arch/powerpc/mm/fsl_booke_mmu.c

b/arch/powerpc/mm/fsl_booke_mmu.c
index 8f60ef8..dd283fd 100644

--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c

@@ -224,7 +224,7 @@ void __init adjust_total_lowmem(void)

	i = switch_to_as1();
	__max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
-	restore_to_as0(i);
+	restore_to_as0(i, 0, 0);

The device tree virtual address is zero?

No. But if the __pa(PAGE_OFFSET in AS0) is equal to __pa(PAGE_OFFSET in AS1),
that mean we don't need to do another relocation and the device tree virtual
address is useless in this case.

The documentation of restore_to_as0() should make it clear that r5 is
ignored if r4 is zero.

-Scott