Re: [Qemu-devel] [PATCH v1 10/22] target-arm: A64: Introduce arm64_banked_spsr_index()

[Peter Crosthwaite]

On Tue, May 6, 2014 at 4:08 PM, Edgar E. Iglesias
<address@hidden> wrote:
> From: "Edgar E. Iglesias" <address@hidden>
>
> Add arm64_banked_spsr_index(), used to map an Exception Level
> to an index in the baked_spsr array.
>
> Signed-off-by: Edgar E. Iglesias <address@hidden>
> ---
>  target-arm/helper-a64.c |  5 +++--
>  target-arm/internals.h  | 14 ++++++++++++++
>  target-arm/op_helper.c  |  3 ++-
>  3 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c
> index 10bd1fc..415efbe 100644
> --- a/target-arm/helper-a64.c
> +++ b/target-arm/helper-a64.c
> @@ -444,6 +444,7 @@ void aarch64_cpu_do_interrupt(CPUState *cs)
>      ARMCPU *cpu = ARM_CPU(cs);
>      CPUARMState *env = &cpu->env;
>      target_ulong addr = env->cp15.vbar_el[VBAR_EL_IDX(1)];
> +    unsigned int spsr_idx = arm64_banked_spsr_index(1);
>      int i;
>
>      if (arm_current_pl(env) == 0) {
> @@ -488,12 +489,12 @@ void aarch64_cpu_do_interrupt(CPUState *cs)
>      }
>
>      if (is_a64(env)) {
> -        env->banked_spsr[0] = pstate_read(env);
> +        env->banked_spsr[spsr_idx] = pstate_read(env);
>          env->sp_el[arm_current_pl(env)] = env->xregs[31];
>          env->xregs[31] = env->sp_el[1];
>          env->elr_el[ELR_EL_IDX(1)] = env->pc;
>      } else {
> -        env->banked_spsr[0] = cpsr_read(env);
> +        env->banked_spsr[spsr_idx] = cpsr_read(env);
>          if (!env->thumb) {
>              env->cp15.esr_el[ESR_EL_IDX(1)] |= 1 << 25;
>          }
> diff --git a/target-arm/internals.h b/target-arm/internals.h
> index d63a975..7c39946 100644
> --- a/target-arm/internals.h
> +++ b/target-arm/internals.h
> @@ -75,6 +75,20 @@ static inline void arm_log_exception(int idx)
>   */
>  #define GTIMER_SCALE 16
>
> +/*
> + * For aarch64, map a given EL to an index in the banked_spsr array.
> + */
> +static inline unsigned int arm64_banked_spsr_index(unsigned int el)
> +{
> +    static const unsigned int map[3] = {
> +        [0] = 0, /* EL1.  */
> +        [1] = 6, /* EL2.  */
> +        [2] = 7, /* EL3.  */

You could just change the [] indicies to [1], [2], [3]

> +    };
> +    assert(el >= 1 && el <= 3);
> +    return map[el - 1];

And drop this subtraction.

Regards,
Peter

> +}
> +
>  int bank_number(int mode);
>  void switch_mode(CPUARMState *, int);
>  void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu);
> diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
> index 21545d0..dd9e4fc 100644
> --- a/target-arm/op_helper.c
> +++ b/target-arm/op_helper.c
> @@ -386,7 +386,8 @@ void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, 
> uint32_t imm)
>
>  void HELPER(exception_return)(CPUARMState *env)
>  {
> -    uint32_t spsr = env->banked_spsr[0];
> +    unsigned int spsr_idx = arm64_banked_spsr_index(1);
> +    uint32_t spsr = env->banked_spsr[spsr_idx];
>      int new_el, i;
>
>      if (env->pstate & PSTATE_SP) {
> --
> 1.8.3.2
>
>