Correct some corner cases we were getting wrong for CNTFRQ access rights: * should UNDEF from 32-bit Secure EL1 * only writable from the highest implemented exception level, which might not be EL1 now
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> --- target-arm/helper.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index 7a8881a..082701a 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -1217,9 +1217,34 @@ static const ARMCPRegInfo v6k_cp_reginfo[] = { static CPAccessResult gt_cntfrq_access(CPUARMState *env, const ARMCPRegInfo *ri, bool isread) { - /* CNTFRQ: not visible from PL0 if both PL0PCTEN and PL0VCTEN are zero */ - if (arm_current_el(env) == 0 && !extract32(env->cp15.c14_cntkctl, 0, 2)) { - return CP_ACCESS_TRAP; + /* CNTFRQ: not visible from PL0 if both PL0PCTEN and PL0VCTEN are zero. + * Writable only at the highest implemented exception level. + */ + switch (arm_current_el(env)) { + case 0: + if (!extract32(env->cp15.c14_cntkctl, 0, 2)) { + return CP_ACCESS_TRAP; + } + /* EL0 reads are forbidden by the .access fields */ + break; + case 1: + if (!isread && (arm_feature(env, ARM_FEATURE_EL2) + || arm_feature(env, ARM_FEATURE_EL3))) { + return CP_ACCESS_TRAP_UNCATEGORIZED; + } + if (!isread && ri->state == ARM_CP_STATE_AA32 && + arm_is_secure_below_el3(env)) { + /* Accesses from 32-bit Secure EL1 UNDEF (*not* trap to EL3!) */ + return CP_ACCESS_TRAP_UNCATEGORIZED; + } + break; + case 2: + if (!isread && arm_feature(env, ARM_FEATURE_EL3)) { + return CP_ACCESS_TRAP_UNCATEGORIZED; + } + break; + case 3: + break; } return CP_ACCESS_OK; } -- 1.9.1