Re: [Qemu-devel] [PATCH v4 14/21] target-arm: Implement AArch64 views of fault status and data registers

[Peter Crosthwaite <peter.crosthwaite@xilinx.com>]

On Fri, Mar 7, 2014 at 5:32 AM, Peter Maydell <peter.maydell@linaro.org> wrote:
> From: Rob Herring <rob.herring@linaro.org>
>
> Implement AArch64 views of ESR_EL1 and FAR_EL1, and make the 32 bit
> DFSR, DFAR, IFAR share state with them as architecturally specified.
> The IFSR doesn't share state with any AArch64 register visible at EL1,
> so just rename the state field without widening it to 64 bits.
>
> Signed-off-by: Rob Herring <rob.herring@linaro.org>
> [PMM: Minor tweaks; fix some bugs involving inconsistencies between
>  use of offsetof() or offsetoflow32() and struct field width]
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  target-arm/cpu.c    |  2 +-
>  target-arm/cpu.h    |  7 +++----
>  target-arm/helper.c | 38 +++++++++++++++++++++++++-------------
>  3 files changed, 29 insertions(+), 18 deletions(-)
>
> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> index 871ed09..948fd44 100644
> --- a/target-arm/cpu.c
> +++ b/target-arm/cpu.c
> @@ -419,7 +419,7 @@ static void arm1026_initfn(Object *obj)
>          ARMCPRegInfo ifar = {
>              .name = "IFAR", .cp = 15, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 1,
>              .access = PL1_RW,
> -            .fieldoffset = offsetof(CPUARMState, cp15.c6_insn),
> +            .fieldoffset = offsetofhigh32(CPUARMState, cp15.far_el1),
>              .resetvalue = 0
>          };
>          define_one_arm_cp_reg(cpu, &ifar);
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index ffa4b37..e51add2 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -181,11 +181,10 @@ typedef struct CPUARMState {
>                          MPU write buffer control.  */
>          uint32_t pmsav5_data_ap; /* PMSAv5 MPU data access permissions */
>          uint32_t pmsav5_insn_ap; /* PMSAv5 MPU insn access permissions */
> -        uint32_t c5_insn; /* Fault status registers.  */
> -        uint32_t c5_data;
> +        uint32_t ifsr_el2; /* Fault status registers.  */
> +        uint64_t esr_el1;
>          uint32_t c6_region[8]; /* MPU base/size registers.  */
> -        uint32_t c6_insn; /* Fault address registers.  */
> -        uint32_t c6_data;
> +        uint64_t far_el1; /* Fault address registers.  */
>          uint32_t c7_par;  /* Translation result. */
>          uint32_t c7_par_hi;  /* Translation result, high 32 bits */
>          uint32_t c9_insn; /* Cache lockdown registers.  */
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index cbef0e5..8d96b5c 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -456,7 +456,8 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
>      { .name = "DMB", .cp = 15, .crn = 7, .crm = 10, .opc1 = 0, .opc2 = 5,
>        .access = PL0_W, .type = ARM_CP_NOP },
>      { .name = "IFAR", .cp = 15, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 2,
> -      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.c6_insn),
> +      .access = PL1_RW,
> +      .fieldoffset = offsetofhigh32(CPUARMState, cp15.far_el1),
>        .resetvalue = 0, },
>      /* Watchpoint Fault Address Register : should actually only be present
>       * for 1136, 1176, 11MPCore.
> @@ -1316,11 +1317,16 @@ static void vmsa_ttbr_write(CPUARMState *env, const ARMCPRegInfo *ri,
>
>  static const ARMCPRegInfo vmsa_cp_reginfo[] = {
>      { .name = "DFSR", .cp = 15, .crn = 5, .crm = 0, .opc1 = 0, .opc2 = 0,
> -      .access = PL1_RW,
> -      .fieldoffset = offsetof(CPUARMState, cp15.c5_data), .resetvalue = 0, },
> +      .access = PL1_RW, .type = ARM_CP_NO_MIGRATE,
> +      .fieldoffset = offsetoflow32(CPUARMState, cp15.esr_el1),
> +      .resetfn = arm_cp_reset_ignore, },
>      { .name = "IFSR", .cp = 15, .crn = 5, .crm = 0, .opc1 = 0, .opc2 = 1,
>        .access = PL1_RW,
> -      .fieldoffset = offsetof(CPUARMState, cp15.c5_insn), .resetvalue = 0, },
> +      .fieldoffset = offsetof(CPUARMState, cp15.ifsr_el2), .resetvalue = 0, },
> +    { .name = "ESR_EL1", .state = ARM_CP_STATE_AA64,
> +      .opc0 = 3, .crn = 5, .crm = 2, .opc1 = 0, .opc2 = 0,
> +      .access = PL1_RW,
> +      .fieldoffset = offsetof(CPUARMState, cp15.esr_el1), .resetvalue = 0, },
>      { .name = "TTBR0_EL1", .state = ARM_CP_STATE_BOTH,
>        .opc0 = 3, .crn = 2, .crm = 0, .opc1 = 0, .opc2 = 0,
>        .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.ttbr0_el1),
> @@ -1338,8 +1344,10 @@ static const ARMCPRegInfo vmsa_cp_reginfo[] = {
>        .access = PL1_RW, .type = ARM_CP_NO_MIGRATE, .writefn = vmsa_ttbcr_write,
>        .resetfn = arm_cp_reset_ignore, .raw_writefn = vmsa_ttbcr_raw_write,
>        .fieldoffset = offsetoflow32(CPUARMState, cp15.c2_control) },
> -    { .name = "DFAR", .cp = 15, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 0,
> -      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.c6_data),
> +    /* 64-bit FAR; this entry also gives us the AArch32 DFAR */
> +    { .name = "FAR_EL1", .state = ARM_CP_STATE_BOTH,
> +      .opc0 = 3, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 0,
> +      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.far_el1),
>        .resetvalue = 0, },
>      REGINFO_SENTINEL
>  };
> @@ -1379,7 +1387,8 @@ static void omap_cachemaint_write(CPUARMState *env, const ARMCPRegInfo *ri,
>  static const ARMCPRegInfo omap_cp_reginfo[] = {
>      { .name = "DFSR", .cp = 15, .crn = 5, .crm = CP_ANY,
>        .opc1 = CP_ANY, .opc2 = CP_ANY, .access = PL1_RW, .type = ARM_CP_OVERRIDE,
> -      .fieldoffset = offsetof(CPUARMState, cp15.c5_data), .resetvalue = 0, },
> +      .fieldoffset = offsetoflow32(CPUARMState, cp15.esr_el1),
> +      .resetvalue = 0, },
>      { .name = "", .cp = 15, .crn = 15, .crm = 0, .opc1 = 0, .opc2 = 0,
>        .access = PL1_RW, .type = ARM_CP_NOP },
>      { .name = "TICONFIG", .cp = 15, .crn = 15, .crm = 1, .opc1 = 0, .opc2 = 0,
> @@ -2979,20 +2988,23 @@ void arm_cpu_do_interrupt(CPUState *cs)
>          env->exception.fsr = 2;
>          /* Fall through to prefetch abort.  */
>      case EXCP_PREFETCH_ABORT:
> -        env->cp15.c5_insn = env->exception.fsr;
> -        env->cp15.c6_insn = env->exception.vaddress;
> +        env->cp15.ifsr_el2 = env->exception.fsr;
> +        env->cp15.far_el1 = deposit64(env->cp15.far_el1, 32, 32,
> +                                      env->exception.vaddress);

Is it better to just grab the CPRegInfo and pass it to raw_write() to
do the deposit dirty work?

Regards,
Peter

>          qemu_log_mask(CPU_LOG_INT, "...with IFSR 0x%x IFAR 0x%x\n",
> -                      env->cp15.c5_insn, env->cp15.c6_insn);
> +                      env->cp15.ifsr_el2, (uint32_t)env->exception.vaddress);
>          new_mode = ARM_CPU_MODE_ABT;
>          addr = 0x0c;
>          mask = CPSR_A | CPSR_I;
>          offset = 4;
>          break;
>      case EXCP_DATA_ABORT:
> -        env->cp15.c5_data = env->exception.fsr;
> -        env->cp15.c6_data = env->exception.vaddress;
> +        env->cp15.esr_el1 = env->exception.fsr;
> +        env->cp15.far_el1 = deposit64(env->cp15.far_el1, 0, 32,
> +                                      env->exception.vaddress);
>          qemu_log_mask(CPU_LOG_INT, "...with DFSR 0x%x DFAR 0x%x\n",
> -                      env->cp15.c5_data, env->cp15.c6_data);
> +                      (uint32_t)env->cp15.esr_el1,
> +                      (uint32_t)env->exception.vaddress);
>          new_mode = ARM_CPU_MODE_ABT;
>          addr = 0x10;
>          mask = CPSR_A | CPSR_I;
> --
> 1.9.0
>
>