Re: [Qemu-devel] [PATCH v8 22/27] target-arm: make IFAR/DFAR banked

[Peter Maydell]

On 30 October 2014 21:28, Greg Bellows <address@hidden> wrote:
> From: Fabian Aggeler <address@hidden>
>
> When EL3 is running in AArch32 (or ARMv7 with Security Extensions)
> IFAR and DFAR have a secure and a non-secure instance.
>
> Signed-off-by: Fabian Aggeler <address@hidden>
> Signed-off-by: Greg Bellows <address@hidden>
>
> ---
>
> v3 -> v4
> - Revert to array-based notation of far_el in combination with v7 naming
> ---
>  target-arm/cpu.c    |  2 +-
>  target-arm/cpu.h    | 19 ++++++++++++++++++-
>  target-arm/helper.c | 20 +++++++++++---------
>  3 files changed, 30 insertions(+), 11 deletions(-)
>
> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> index 18f4726..a711834 100644
> --- a/target-arm/cpu.c
> +++ b/target-arm/cpu.c
> @@ -522,7 +522,7 @@ static void arm1026_initfn(Object *obj)
>          ARMCPRegInfo ifar = {
>              .name = "IFAR", .cp = 15, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 
> 1,
>              .access = PL1_RW,
> -            .fieldoffset = offsetofhigh32(CPUARMState, cp15.far_el[1]),
> +            .fieldoffset = offsetof(CPUARMState, cp15.ifar_ns),
>              .resetvalue = 0
>          };
>          define_one_arm_cp_reg(cpu, &ifar);
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 29bf273..10985d4 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -270,7 +270,24 @@ typedef struct CPUARMState {
>              uint64_t esr_el[4];
>          };
>          uint32_t c6_region[8]; /* MPU base/size registers.  */
> -        uint64_t far_el[4]; /* Fault address registers.  */
> +        union { /* Fault address registers. */
> +            struct {
> +                uint64_t _unused_far0;
> +#ifdef HOST_WORDS_BIGENDIAN
> +                uint32_t ifar_ns;
> +                uint32_t dfar_ns;
> +                uint32_t ifar_s;
> +                uint32_t dfar_s;
> +#else
> +                uint32_t dfar_ns;
> +                uint32_t ifar_ns;
> +                uint32_t dfar_s;
> +                uint32_t ifar_s;
> +#endif

This is pretty ugly but I guess I can live with it.

> +                uint64_t _unused_far3;;

Stray extra semicolon.

> +            };
> +            uint64_t far_el[4];
> +        };
>          uint64_t par_el1;  /* Translation result. */
>          uint32_t c9_insn; /* Cache lockdown registers.  */
>          uint32_t c9_data;
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index c5948f7..c4d0db4 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -554,7 +554,8 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
>        .access = PL0_W, .type = ARM_CP_NOP },
>      { .name = "IFAR", .cp = 15, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 2,
>        .access = PL1_RW,
> -      .fieldoffset = offsetofhigh32(CPUARMState, cp15.far_el[1]),
> +      .bank_fieldoffsets = { offsetof(CPUARMState, cp15.ifar_s),
> +                             offsetof(CPUARMState, cp15.ifar_ns) },
>        .resetvalue = 0, },
>      /* Watchpoint Fault Address Register : should actually only be present
>       * for 1136, 1176, 11MPCore.
> @@ -1681,11 +1682,14 @@ static const ARMCPRegInfo vmsa_cp_reginfo[] = {
>        .resetfn = arm_cp_reset_ignore, .raw_writefn = vmsa_ttbcr_raw_write,
>        .bank_fieldoffsets = { offsetoflow32(CPUARMState, cp15.ttbcr_s),
>                               offsetoflow32(CPUARMState, cp15.ttbcr_ns) } },
> -    /* 64-bit FAR; this entry also gives us the AArch32 DFAR */
> -    { .name = "FAR_EL1", .state = ARM_CP_STATE_BOTH,
> +    { .name = "DFAR", .cp = 15, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 0,
> +      .access = PL1_RW, .resetvalue = 0,
> +      .bank_fieldoffsets = { offsetof(CPUARMState, cp15.dfar_s),
> +                             offsetof(CPUARMState, cp15.dfar_ns) } },
> +    { .name = "FAR_EL1", .state = ARM_CP_STATE_AA64,
>        .opc0 = 3, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 0,
> -      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.far_el[1]),
> -      .resetvalue = 0, },
> +      .access = PL1_RW, .resetvalue = 0,
> +      .fieldoffset = offsetof(CPUARMState, cp15.far_el[1]) },

This change just seems to be rearranging the fields for no particular reason?

>      REGINFO_SENTINEL
>  };
>
> @@ -4300,8 +4304,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
>          /* Fall through to prefetch abort.  */
>      case EXCP_PREFETCH_ABORT:
>          A32_BANKED_CURRENT_REG_SET(env, ifsr, env->exception.fsr);
> -        env->cp15.far_el[1] = deposit64(env->cp15.far_el[1], 32, 32,
> -                                        env->exception.vaddress);
> +        A32_BANKED_CURRENT_REG_SET(env, ifar, env->exception.vaddress);
>          qemu_log_mask(CPU_LOG_INT, "...with IFSR 0x%x IFAR 0x%x\n",
>                        env->exception.fsr, (uint32_t)env->exception.vaddress);
>          new_mode = ARM_CPU_MODE_ABT;
> @@ -4311,8 +4314,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
>          break;
>      case EXCP_DATA_ABORT:
>          A32_BANKED_CURRENT_REG_SET(env, dfsr, env->exception.fsr);
> -        env->cp15.far_el[1] = deposit64(env->cp15.far_el[1], 0, 32,
> -                                        env->exception.vaddress);
> +        A32_BANKED_CURRENT_REG_SET(env, dfar, env->exception.vaddress);
>          qemu_log_mask(CPU_LOG_INT, "...with DFSR 0x%x DFAR 0x%x\n",
>                        env->exception.fsr,
>                        (uint32_t)env->exception.vaddress);

Otherwise has my reviewed-by.

-- PMM