From 7655abb953860485940d4de74fb45a8192149bb6 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 10 Aug 2017 13:19:09 +0100 Subject: arm64: mm: Move ASID from TTBR0 to TTBR1 In preparation for mapping kernelspace and userspace with different ASIDs, move the ASID to TTBR1 and update switch_mm to context-switch TTBR0 via an invalid mapping (the zero page). Reviewed-by: Mark Rutland Tested-by: Laura Abbott Tested-by: Shanker Donthineni Signed-off-by: Will Deacon --- arch/arm64/mm/proc.S | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'arch/arm64/mm') diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 95233dfc4c39..a8a64898a2aa 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -139,9 +139,12 @@ ENDPROC(cpu_do_resume) */ ENTRY(cpu_do_switch_mm) pre_ttbr0_update_workaround x0, x2, x3 + mrs x2, ttbr1_el1 mmid x1, x1 // get mm->context.id - bfi x0, x1, #48, #16 // set the ASID - msr ttbr0_el1, x0 // set TTBR0 + bfi x2, x1, #48, #16 // set the ASID + msr ttbr1_el1, x2 // in TTBR1 (since TCR.A1 is set) + isb + msr ttbr0_el1, x0 // now update TTBR0 isb post_ttbr0_update_workaround ret @@ -224,7 +227,7 @@ ENTRY(__cpu_setup) * both user and kernel. */ ldr x10, =TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \ - TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0 + TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0 | TCR_A1 tcr_set_idmap_t0sz x10, x9 /* -- cgit v1.2.3