Re: [Qemu-devel] [PATCH 09/14] target-arm: Add AArch64 CPTR registers

["Edgar E. Iglesias" <edgar.iglesias@xilinx.com>]

On Tue, May 19, 2015 at 07:33:29PM +0100, Peter Maydell wrote:
> From: Greg Bellows <greg.bellows@linaro.org>
> 
> Adds CPTR_EL2/3 system registers definitions and access function.
> 
> Signed-off-by: Greg Bellows <greg.bellows@linaro.org>
> [PMM: merge CPTR_EL2 and HCPTR definitions into a single
>  def using STATE_BOTH;
>  don't use readfn/writefn to implement RAZ/WI registers;
>  don't use accessfn for the no-EL2 CPTR_EL2;
>  fix cpacr_access logic to catch EL2 accesses to CPACR being
>  trapped to EL3;
>  use new CP_ACCESS_TRAP_EL[23] rather than setting
>  exception.target_el directly]
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>


> ---
>  target-arm/cpu.h    |  5 +++++
>  target-arm/helper.c | 40 +++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index e431372..8cc4bc9 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -197,6 +197,7 @@ typedef struct CPUARMState {
>              uint64_t sctlr_el[4];
>          };
>          uint64_t cpacr_el1; /* Architectural feature access control register */
> +        uint64_t cptr_el[4];  /* ARMv8 feature trap registers */
>          uint32_t c1_xscaleauxcr; /* XScale auxiliary control register.  */
>          uint64_t sder; /* Secure debug enable register. */
>          uint32_t nsacr; /* Non-secure access control register. */
> @@ -568,6 +569,10 @@ void pmccntr_sync(CPUARMState *env);
>  #define SCTLR_AFE     (1U << 29)
>  #define SCTLR_TE      (1U << 30)
>  
> +#define CPTR_TCPAC    (1U << 31)
> +#define CPTR_TTA      (1U << 20)
> +#define CPTR_TFP      (1U << 10)
> +
>  #define CPSR_M (0x1fU)
>  #define CPSR_T (1U << 5)
>  #define CPSR_F (1U << 6)
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index abfd70e..1cc4993 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -592,6 +592,33 @@ static void cpacr_write(CPUARMState *env, const ARMCPRegInfo *ri,
>      env->cp15.cpacr_el1 = value;
>  }
>  
> +static CPAccessResult cpacr_access(CPUARMState *env, const ARMCPRegInfo *ri)
> +{
> +    if (arm_feature(env, ARM_FEATURE_V8)) {
> +        /* Check if CPACR accesses are to be trapped to EL2 */
> +        if (arm_current_el(env) == 1 &&
> +            (env->cp15.cptr_el[2] & CPTR_TCPAC) && !arm_is_secure(env)) {
> +            return CP_ACCESS_TRAP_EL2;
> +        /* Check if CPACR accesses are to be trapped to EL3 */
> +        } else if (arm_current_el(env) < 3 &&
> +                   (env->cp15.cptr_el[3] & CPTR_TCPAC)) {
> +            return CP_ACCESS_TRAP_EL3;
> +        }
> +    }
> +
> +    return CP_ACCESS_OK;
> +}
> +
> +static CPAccessResult cptr_access(CPUARMState *env, const ARMCPRegInfo *ri)
> +{
> +    /* Check if CPTR accesses are set to trap to EL3 */
> +    if (arm_current_el(env) == 2 && (env->cp15.cptr_el[3] & CPTR_TCPAC)) {
> +        return CP_ACCESS_TRAP_EL3;
> +    }
> +
> +    return CP_ACCESS_OK;
> +}
> +
>  static const ARMCPRegInfo v6_cp_reginfo[] = {
>      /* prefetch by MVA in v6, NOP in v7 */
>      { .name = "MVA_prefetch",
> @@ -614,7 +641,7 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
>      { .name = "WFAR", .cp = 15, .crn = 6, .crm = 0, .opc1 = 0, .opc2 = 1,
>        .access = PL1_RW, .type = ARM_CP_CONST, .resetvalue = 0, },
>      { .name = "CPACR", .state = ARM_CP_STATE_BOTH, .opc0 = 3,
> -      .crn = 1, .crm = 0, .opc1 = 0, .opc2 = 2,
> +      .crn = 1, .crm = 0, .opc1 = 0, .opc2 = 2, .accessfn = cpacr_access,
>        .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.cpacr_el1),
>        .resetvalue = 0, .writefn = cpacr_write },
>      REGINFO_SENTINEL
> @@ -2481,6 +2508,9 @@ static const ARMCPRegInfo v8_el3_no_el2_cp_reginfo[] = {
>        .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 1, .opc2 = 0,
>        .access = PL2_RW,
>        .readfn = arm_cp_read_zero, .writefn = arm_cp_write_ignore },
> +    { .name = "CPTR_EL2", .state = ARM_CP_STATE_BOTH,
> +      .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 1, .opc2 = 2,
> +      .access = PL2_RW, .type = ARM_CP_CONST, .resetvalue = 0 },
>      REGINFO_SENTINEL
>  };
>  
> @@ -2548,6 +2578,10 @@ static const ARMCPRegInfo v8_el2_cp_reginfo[] = {
>        .opc0 = 3, .opc1 = 6, .crn = 4, .crm = 1, .opc2 = 0,
>        .access = PL3_RW, .type = ARM_CP_ALIAS,
>        .fieldoffset = offsetof(CPUARMState, sp_el[2]) },
> +    { .name = "CPTR_EL2", .state = ARM_CP_STATE_BOTH,
> +      .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 1, .opc2 = 2,
> +      .access = PL2_RW, .accessfn = cptr_access, .resetvalue = 0,
> +      .fieldoffset = offsetof(CPUARMState, cp15.cptr_el[2]) },
>      REGINFO_SENTINEL
>  };
>  
> @@ -2609,6 +2643,10 @@ static const ARMCPRegInfo el3_cp_reginfo[] = {
>        .access = PL3_RW, .writefn = vbar_write,
>        .fieldoffset = offsetof(CPUARMState, cp15.vbar_el[3]),
>        .resetvalue = 0 },
> +    { .name = "CPTR_EL3", .state = ARM_CP_STATE_AA64,
> +      .opc0 = 3, .opc1 = 6, .crn = 1, .crm = 1, .opc2 = 2,
> +      .access = PL3_RW, .accessfn = cptr_access, .resetvalue = 0,
> +      .fieldoffset = offsetof(CPUARMState, cp15.cptr_el[3]) },
>      REGINFO_SENTINEL
>  };
>  
> -- 
> 1.9.1
>