diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S index 9e9c6140cd4..b3eef705a53 100644 --- a/arch/arm/cpu/armv8/start.S +++ b/arch/arm/cpu/armv8/start.S @@ -127,10 +127,6 @@ pie_fixup_done: orr x0, x0, #0xf /* SCR_EL3.NS|IRQ|FIQ|EA */ msr scr_el3, x0 msr cptr_el3, xzr /* Enable FP/SIMD */ -#ifdef COUNTER_FREQUENCY - ldr x0, =COUNTER_FREQUENCY - msr cntfrq_el0, x0 /* Initialize CNTFRQ */ -#endif b 0f 2: mrs x1, hcr_el2 tbnz x1, #34, 1f /* HCR_EL2.E2H */ @@ -142,7 +138,14 @@ pie_fixup_done: mov x0, #3 << 20 msr cpacr_el1, x0 /* Enable FP/SIMD */ 0: - isb + +#ifdef COUNTER_FREQUENCY + branch_if_not_highest_el x0, 4f + ldr x0, =COUNTER_FREQUENCY + msr cntfrq_el0, x0 /* Initialize CNTFRQ */ +#endif + +4: isb /* * Enable SMPEN bit for coherency. diff --git a/arch/arm/include/asm/macro.h b/arch/arm/include/asm/macro.h index bb33b4bc892..485310d6608 100644 --- a/arch/arm/include/asm/macro.h +++ b/arch/arm/include/asm/macro.h @@ -77,6 +77,24 @@ lr .req x30 b.eq \el1_label .endm +/* + * Branch if we are not in the highest exception level + */ +.macro branch_if_not_highest_el, xreg, label + switch_el \xreg, 3f, 2f, 1f + +2: mrs \xreg, ID_AA64PFR0_EL1 + and \xreg, \xreg, #(ID_AA64PFR0_EL1_EL3) + cbnz \xreg, \label + b 3f + +1: mrs \xreg, ID_AA64PFR0_EL1 + and \xreg, \xreg, #(ID_AA64PFR0_EL1_EL3 | ID_AA64PFR0_EL1_EL2) + cbnz \xreg, \label + +3: +.endm + /* * Branch if current processor is a Cortex-A57 core. */ diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index 11fceec4d2f..8b3a54e64c8 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -79,6 +79,12 @@ #define HCR_EL2_RW_AARCH32 (0 << 31) /* Lower levels are AArch32 */ #define HCR_EL2_HCD_DIS (1 << 29) /* Hypervisor Call disabled */ +/* + * ID_AA64PFR0_EL1 bits definitions + */ +#define ID_AA64PFR0_EL1_EL3 (0xF << 12) /* EL3 implemented */ +#define ID_AA64PFR0_EL1_EL2 (0xF << 8) /* EL2 implemented */ + /* * CPACR_EL1 bits definitions */