From dd006da21646f1c86f0242eb8f527d093303127a Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 19 Mar 2015 16:42:27 +0000 Subject: arm64: mm: increase VA range of identity map The page size and the number of translation levels, and hence the supported virtual address range, are build-time configurables on arm64 whose optimal values are use case dependent. However, in the current implementation, if the system's RAM is located at a very high offset, the virtual address range needs to reflect that merely because the identity mapping, which is only used to enable or disable the MMU, requires the extended virtual range to map the physical memory at an equal virtual offset. This patch relaxes that requirement, by increasing the number of translation levels for the identity mapping only, and only when actually needed, i.e., when system RAM's offset is found to be out of reach at runtime. Tested-by: Laura Abbott Reviewed-by: Catalin Marinas Tested-by: Marc Zyngier Signed-off-by: Ard Biesheuvel Signed-off-by: Will Deacon --- arch/arm64/kernel/smp.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm64/kernel/smp.c') diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 4257369341e4..ffe8e1b814e0 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -151,6 +151,7 @@ asmlinkage void secondary_start_kernel(void) */ cpu_set_reserved_ttbr0(); flush_tlb_all(); + cpu_set_default_tcr_t0sz(); preempt_disable(); trace_hardirqs_off(); -- cgit v1.2.3