From 3bef7012560a7f0ea27b265105de5090ba117514 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 2 Jun 2017 11:51:49 +0100 Subject: arm: Implement HFNMIENA support for M profile MPU Implement HFNMIENA support for the M profile MPU. This bit controls whether the MPU is treated as enabled when executing at execution priorities of less than zero (in NMI, HardFault or with the FAULTMASK bit set). Doing this requires us to use a different MMU index for "running at execution priority < 0", because we will have different access permissions for that case versus the normal case. Signed-off-by: Peter Maydell Message-id: 1493122030-32191-14-git-send-email-peter.maydell@linaro.org --- target/arm/helper.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'target/arm/helper.c') diff --git a/target/arm/helper.c b/target/arm/helper.c index 674b52dea0..2594faa9b8 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -7037,6 +7037,7 @@ static inline uint32_t regime_el(CPUARMState *env, ARMMMUIdx mmu_idx) case ARMMMUIdx_S1NSE0: case ARMMMUIdx_S1NSE1: case ARMMMUIdx_MPriv: + case ARMMMUIdx_MNegPri: case ARMMMUIdx_MUser: return 1; default: @@ -7055,6 +7056,7 @@ static inline bool regime_is_secure(CPUARMState *env, ARMMMUIdx mmu_idx) case ARMMMUIdx_S1E2: case ARMMMUIdx_S2NS: case ARMMMUIdx_MPriv: + case ARMMMUIdx_MNegPri: case ARMMMUIdx_MUser: return false; case ARMMMUIdx_S1E3: @@ -7077,7 +7079,21 @@ static inline bool regime_translation_disabled(CPUARMState *env, ARMMMUIdx mmu_idx) { if (arm_feature(env, ARM_FEATURE_M)) { - return !(env->v7m.mpu_ctrl & R_V7M_MPU_CTRL_ENABLE_MASK); + switch (env->v7m.mpu_ctrl & + (R_V7M_MPU_CTRL_ENABLE_MASK | R_V7M_MPU_CTRL_HFNMIENA_MASK)) { + case R_V7M_MPU_CTRL_ENABLE_MASK: + /* Enabled, but not for HardFault and NMI */ + return mmu_idx == ARMMMUIdx_MNegPri; + case R_V7M_MPU_CTRL_ENABLE_MASK | R_V7M_MPU_CTRL_HFNMIENA_MASK: + /* Enabled for all cases */ + return false; + case 0: + default: + /* HFNMIENA set and ENABLE clear is UNPREDICTABLE, but + * we warned about that in armv7m_nvic.c when the guest set it. + */ + return true; + } } if (mmu_idx == ARMMMUIdx_S2NS) { -- cgit v1.2.3