From ae8a8b9553bd3906af74ff4e8d763904d20ab4e5 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 3 Apr 2013 17:16:57 +0100 Subject: ARM: 7691/1: mm: kill unused TLB_CAN_READ_FROM_L1_CACHE and use ALT_SMP instead Many ARMv7 cores have hardware page table walkers that can read the L1 cache. This is discoverable from the ID_MMFR3 register, although this can be expensive to access from the low-level set_pte functions and is a pain to cache, particularly with multi-cluster systems. A useful observation is that the multi-processing extensions for ARMv7 require coherent table walks, meaning that we can make use of ALT_SMP patching in proc-v7-* to patch away the cache flush safely for these cores. Reported-by: Albin Tonnerre Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/mm/proc-v7-3level.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm/mm/proc-v7-3level.S') diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S index 6ffd78c0f9ab..363027e811d6 100644 --- a/arch/arm/mm/proc-v7-3level.S +++ b/arch/arm/mm/proc-v7-3level.S @@ -73,7 +73,8 @@ ENTRY(cpu_v7_set_pte_ext) tst r3, #1 << (55 - 32) @ L_PTE_DIRTY orreq r2, #L_PTE_RDONLY 1: strd r2, r3, [r0] - mcr p15, 0, r0, c7, c10, 1 @ flush_pte + ALT_SMP(mov pc, lr) + ALT_UP (mcr p15, 0, r0, c7, c10, 1) @ flush_pte #endif mov pc, lr ENDPROC(cpu_v7_set_pte_ext) -- cgit v1.2.3