[PATCH] ARM: vector_table: Fix creation of second level page table

Sascha Hauer s.hauer at pengutronix.de
Wed Aug 24 05:23:10 PDT 2016

The second level page tables can only start at a 1MiB section boundary,
so instead of calling arm_create_pte() with the high vector address
(which is 0xffff0000, not 1MiB aligned) we have to call it with
0xfff00000 to correctly create a second level page table. The vectors
themselves worked as expected with the old value, but the memory around
it did not do a 1:1 mapping anymore. This breaks SoCs which have
peripherals in that area, for example Atmel SoCs like the AT91RM9200.

Fixes: f6b77fe9: ARM: Rework vector table setup

Reported-by: Peter Kardos <kardos.peter.sk at gmail.com>
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
 arch/arm/cpu/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/cpu/mmu.c b/arch/arm/cpu/mmu.c
index a31bce4..2b70866 100644
--- a/arch/arm/cpu/mmu.c
+++ b/arch/arm/cpu/mmu.c
@@ -307,7 +307,7 @@ static void create_vector_table(unsigned long adr)
 		vectors = xmemalign(PAGE_SIZE, PAGE_SIZE);
 		pr_debug("Creating vector table, virt = 0x%p, phys = 0x%08lx\n",
 			 vectors, adr);
-		exc = arm_create_pte(adr);
+		exc = arm_create_pte(adr & ~(SZ_1M - 1));
 		idx = (adr & (SZ_1M - 1)) >> PAGE_SHIFT;
 		exc[idx] = (u32)vectors | PTE_TYPE_SMALL | pte_flags_cached;

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