diff --git a/arch/arm/mach-mvebu/coherency_ll.S b/arch/arm/mach-mvebu/coherency_ll.S index f5d881b5d0f7..8b2fbc8b6bc6 100644 --- a/arch/arm/mach-mvebu/coherency_ll.S +++ b/arch/arm/mach-mvebu/coherency_ll.S @@ -24,7 +24,10 @@ #include .text -/* Returns the coherency base address in r1 (r0 is untouched) */ +/* + * Returns the coherency base address in r1 (r0 is untouched), or 0 if + * the coherency fabric is not enabled. + */ ENTRY(ll_get_coherency_base) mrc p15, 0, r1, c1, c0, 0 tst r1, #CR_M @ Check MMU bit enabled @@ -32,8 +35,13 @@ ENTRY(ll_get_coherency_base) /* * MMU is disabled, use the physical address of the coherency - * base address. + * base address. However, if the coherency fabric isn't mapped + * (i.e its virtual address is zero), it means coherency is + * not enabled, so we return 0. */ + ldr r1, =coherency_base + cmp r1, #0 + beq 2f adr r1, 3f ldr r3, [r1] ldr r1, [r1, r3] @@ -85,6 +93,9 @@ ENTRY(ll_add_cpu_to_smp_group) */ mov r0, lr bl ll_get_coherency_base + /* Bail out if the coherency is not enabled */ + cmp r1, #0 + reteq r0 bl ll_get_coherency_cpumask mov lr, r0 add r0, r1, #ARMADA_XP_CFB_CFG_REG_OFFSET @@ -107,6 +118,9 @@ ENTRY(ll_enable_coherency) */ mov r0, lr bl ll_get_coherency_base + /* Bail out if the coherency is not enabled */ + cmp r1, #0 + reteq r0 bl ll_get_coherency_cpumask mov lr, r0 add r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET @@ -131,6 +145,9 @@ ENTRY(ll_disable_coherency) */ mov r0, lr bl ll_get_coherency_base + /* Bail out if the coherency is not enabled */ + cmp r1, #0 + reteq r0 bl ll_get_coherency_cpumask mov lr, r0 add r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET