[PATCH v2] ARM: vector_table: Fix creation of second level page table

Sascha Hauer s.hauer at pengutronix.de
Wed Aug 24 23:36:32 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 old values broke SoCs which have peripherals in the upper 1MiB
area, like for example the Atmel AT91RM9200. On these Socs we correctly
created the vector page, but the pages around it did not have a 1:1
mapping anymore which led to unreachable peripherals.

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>

Changes since v1:
- Use ALIGN_DOWN instead of open coded alignment
- more clear commit message

 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..459abe5 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(ALIGN_DOWN(adr, SZ_1M));
 		idx = (adr & (SZ_1M - 1)) >> PAGE_SHIFT;
 		exc[idx] = (u32)vectors | PTE_TYPE_SMALL | pte_flags_cached;

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