Re: [Qemu-devel] [Qemu-arm] [PATCH 16/20] target/arm: Factor out "get mmuidx for specified security state"

[Philippe Mathieu-Daudé]

On 09/22/2017 12:00 PM, Peter Maydell wrote:
> For the SG instruction and secure function return we are going
> to want to do memory accesses using the MMU index of the CPU
> in secure state, even though the CPU is currently in non-secure
> state. Write arm_v7m_mmu_idx_for_secstate() to do this job,
> and use it in cpu_mmu_index().
> 
> Signed-off-by: Peter Maydell <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>  target/arm/cpu.h | 32 +++++++++++++++++++++-----------
>  1 file changed, 21 insertions(+), 11 deletions(-)
> 
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index 70c1f85..89d49cd 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -2329,23 +2329,33 @@ static inline int arm_mmu_idx_to_el(ARMMMUIdx mmu_idx)
>      }
>  }
>  
> +/* Return the MMU index for a v7M CPU in the specified security state */
> +static inline ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env,
> +                                                     bool secstate)
> +{
> +    int el = arm_current_el(env);
> +    ARMMMUIdx mmu_idx;
> +
> +    if (el == 0) {
> +        mmu_idx = secstate ? ARMMMUIdx_MSUser : ARMMMUIdx_MUser;
> +    } else {
> +        mmu_idx = secstate ? ARMMMUIdx_MSPriv : ARMMMUIdx_MPriv;
> +    }
> +
> +    if (armv7m_nvic_neg_prio_requested(env->nvic, secstate)) {
> +        mmu_idx = secstate ? ARMMMUIdx_MSNegPri : ARMMMUIdx_MNegPri;
> +    }
> +
> +    return mmu_idx;
> +}
> +
>  /* Determine the current mmu_idx to use for normal loads/stores */
>  static inline int cpu_mmu_index(CPUARMState *env, bool ifetch)
>  {
>      int el = arm_current_el(env);
>  
>      if (arm_feature(env, ARM_FEATURE_M)) {
> -        ARMMMUIdx mmu_idx;
> -
> -        if (el == 0) {
> -            mmu_idx = env->v7m.secure ? ARMMMUIdx_MSUser : ARMMMUIdx_MUser;
> -        } else {
> -            mmu_idx = env->v7m.secure ? ARMMMUIdx_MSPriv : ARMMMUIdx_MPriv;
> -        }
> -
> -        if (armv7m_nvic_neg_prio_requested(env->nvic, env->v7m.secure)) {
> -            mmu_idx = env->v7m.secure ? ARMMMUIdx_MSNegPri : 
> ARMMMUIdx_MNegPri;
> -        }
> +        ARMMMUIdx mmu_idx = arm_v7m_mmu_idx_for_secstate(env, 
> env->v7m.secure);
>  
>          return arm_to_core_mmu_idx(mmu_idx);
>      }
>