Re: [Qemu-devel] [PATCH v3 08/16] target-arm: Add SCR_EL3

[Peter Maydell]

On 17 June 2014 09:45, Edgar E. Iglesias <address@hidden> wrote:
> From: "Edgar E. Iglesias" <address@hidden>
>
> Signed-off-by: Edgar E. Iglesias <address@hidden>
> ---
>  target-arm/cpu.h    | 16 +++++++++++++++-
>  target-arm/helper.c | 31 ++++++++++++++++++++++++++++++-
>  2 files changed, 45 insertions(+), 2 deletions(-)
>
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index fd57fb5..fa8dee0 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -172,7 +172,6 @@ typedef struct CPUARMState {
>          uint64_t c1_sys; /* System control register.  */
>          uint64_t c1_coproc; /* Coprocessor access register.  */
>          uint32_t c1_xscaleauxcr; /* XScale auxiliary control register.  */
> -        uint32_t c1_scr; /* secure config register.  */
>          uint64_t ttbr0_el1; /* MMU translation table base 0. */
>          uint64_t ttbr1_el1; /* MMU translation table base 1. */
>          uint64_t c2_control; /* MMU translation table base control.  */
> @@ -185,6 +184,7 @@ typedef struct CPUARMState {
>          uint32_t pmsav5_data_ap; /* PMSAv5 MPU data access permissions */
>          uint32_t pmsav5_insn_ap; /* PMSAv5 MPU insn access permissions */
>          uint64_t hcr_el2; /* Hypervisor configuration register */
> +        uint32_t scr_el3; /* Secure configuration register.  */
>          uint32_t ifsr_el2; /* Fault status registers.  */
>          uint64_t esr_el[4];
>          uint32_t c6_region[8]; /* MPU base/size registers.  */
> @@ -562,6 +562,20 @@ static inline void xpsr_write(CPUARMState *env, uint32_t 
> val, uint32_t mask)
>  #define HCR_ID        (1ULL << 33)
>  #define HCR_MASK      ((1ULL << 34) - 1)
>
> +#define SCR_NS        (1U << 0)
> +#define SCR_IRQ       (1U << 1)
> +#define SCR_FIQ       (1U << 2)
> +#define SCR_EA        (1U << 3)
> +#define SCR_SMD       (1U << 7)
> +#define SCR_HCE       (1U << 8)
> +#define SCR_SIF       (1U << 9)
> +#define SCR_RW        (1U << 10)
> +#define SCR_ST        (1U << 11)
> +#define SCR_TWI       (1U << 12)
> +#define SCR_TWE       (1U << 13)
> +#define SCR_RES1_MASK (3U << 4)
> +#define SCR_MASK      (0x3fff & ~SCR_RES1_MASK)
> +
>  /* Return the current FPSCR value.  */
>  uint32_t vfp_get_fpscr(CPUARMState *env);
>  void vfp_set_fpscr(CPUARMState *env, uint32_t val);
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index b04fb5d..6bacc24 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -793,7 +793,7 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
>        .fieldoffset = offsetof(CPUARMState, cp15.vbar_el[1]),
>        .resetvalue = 0 },
>      { .name = "SCR", .cp = 15, .crn = 1, .crm = 1, .opc1 = 0, .opc2 = 0,
> -      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.c1_scr),
> +      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.scr_el3),
>        .resetvalue = 0, },

It's awkward that this is now separate from the AArch64 reginfo
below, because it makes it non-obvious that they're both the
same underlying state. In particular that probably means this
one now needs a NO_MIGRATE marker?

>      { .name = "CCSIDR", .state = ARM_CP_STATE_BOTH,
>        .opc0 = 3, .crn = 0, .crm = 0, .opc1 = 1, .opc2 = 0,
> @@ -2161,6 +2161,31 @@ static const ARMCPRegInfo v8_el2_cp_reginfo[] = {
>      REGINFO_SENTINEL
>  };
>
> +static void scr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t 
> value)
> +{
> +    uint32_t valid_mask = SCR_MASK;
> +
> +    if (!arm_feature(env, ARM_FEATURE_EL2)) {
> +        valid_mask &= ~SCR_HCE;
> +
> +        /* On ARMv7, SMD (or SCD as it is called in v7) is only
> +         * supported if EL2 exists. The bit is UNK/SBZP when
> +         * EL2 is unavailable. In QEMU ARMv7, we force it to always zero
> +         * when EL2 is unavailable.
> +         */
> +        if (arm_feature(env, ARM_FEATURE_V7)) {
> +            valid_mask &= ~SCR_SMD;
> +        }
> +    }
> +
> +    /* Set RES1 bits.  */
> +    value |= SCR_RES1_MASK;
> +
> +    /* Clear RES0 bits.  */
> +    value &= valid_mask;
> +    raw_write(env, ri, value);
> +}
> +
>  static const ARMCPRegInfo v8_el3_cp_reginfo[] = {
>      { .name = "ELR_EL3", .state = ARM_CP_STATE_AA64,
>        .type = ARM_CP_NO_MIGRATE,
> @@ -2183,6 +2208,10 @@ static const ARMCPRegInfo v8_el3_cp_reginfo[] = {
>        .access = PL3_RW, .writefn = vbar_write,
>        .fieldoffset = offsetof(CPUARMState, cp15.vbar_el[3]),
>        .resetvalue = 0 },
> +    { .name = "SCR_EL3", .state = ARM_CP_STATE_AA64,
> +      .opc0 = 3, .opc1 = 6, .crn = 1, .crm = 1, .opc2 = 0,
> +      .access = PL3_RW, .fieldoffset = offsetof(CPUARMState, cp15.scr_el3),
> +      .writefn = scr_write },
>      REGINFO_SENTINEL
>  };

thanks
-- PMM