From: Alexandru Elisei <alexandru.elisei@xxxxxxx> Let's invalidate the TLB before enabling the MMU, not after, so we don't accidently use a stale TLB mapping. For arm, we add a TLBIALL operation, which applies only to the PE that executed the instruction [1]. For arm64, we already do that in asm_mmu_enable. We now find ourselves in a situation where we issue an extra invalidation after asm_mmu_enable returns. Remove this redundant call to tlb_flush_all. [1] ARM DDI 0406C.d, section B3.10.6 Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx> Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx> --- arm/cstart.S | 4 ++++ lib/arm/mmu.c | 1 - 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/arm/cstart.S b/arm/cstart.S index 8c041da50ae2..e54e380e0d53 100644 --- a/arm/cstart.S +++ b/arm/cstart.S @@ -166,6 +166,10 @@ halt: .equ NMRR, 0xff000004 @ MAIR1 (from Linux kernel) .globl asm_mmu_enable asm_mmu_enable: + /* TLBIALL */ + mcr p15, 0, r2, c8, c7, 0 + dsb nsh + /* TTBCR */ ldr r2, =(TTBCR_EAE | \ TTBCR_SH0_SHARED | \ diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c index 111e3a52591a..5fb56180d334 100644 --- a/lib/arm/mmu.c +++ b/lib/arm/mmu.c @@ -59,7 +59,6 @@ void mmu_enable(pgd_t *pgtable) struct thread_info *info = current_thread_info(); asm_mmu_enable(__pa(pgtable)); - flush_tlb_all(); info->pgtable = pgtable; mmu_mark_enabled(info->cpu); -- 2.21.0
