Re: [Qemu-devel] [PATCH v2 13/16] target/arm: Move cpu_get_tb_cpu_state out of line

[Richard Henderson <richard.henderson@linaro.org>]

On 01/22/2018 07:07 AM, Alex Bennée wrote:
> 
> Richard Henderson <richard.henderson@linaro.org> writes:
> 
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>  target/arm/cpu.h    | 127 +---------------------------------------------------
>>  target/arm/helper.c | 126
>> +++++++++++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 128 insertions(+), 125 deletions(-)
>>
>> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
>> index c8e8155b6e..2de1afb53a 100644
>> --- a/target/arm/cpu.h
>> +++ b/target/arm/cpu.h
>> @@ -2703,71 +2703,6 @@ static inline bool bswap_code(bool sctlr_b)
>>  #endif
>>  }
>>
>> -/* Return the exception level to which FP-disabled exceptions should
>> - * be taken, or 0 if FP is enabled.
>> - */
>> -static inline int fp_exception_el(CPUARMState *env)
>> -{
>> -    int fpen;
>> -    int cur_el = arm_current_el(env);
>> -
>> -    /* CPACR and the CPTR registers don't exist before v6, so FP is
>> -     * always accessible
>> -     */
>> -    if (!arm_feature(env, ARM_FEATURE_V6)) {
>> -        return 0;
>> -    }
>> -
>> -    /* The CPACR controls traps to EL1, or PL1 if we're 32 bit:
>> -     * 0, 2 : trap EL0 and EL1/PL1 accesses
>> -     * 1    : trap only EL0 accesses
>> -     * 3    : trap no accesses
>> -     */
>> -    fpen = extract32(env->cp15.cpacr_el1, 20, 2);
>> -    switch (fpen) {
>> -    case 0:
>> -    case 2:
>> -        if (cur_el == 0 || cur_el == 1) {
>> -            /* Trap to PL1, which might be EL1 or EL3 */
>> -            if (arm_is_secure(env) && !arm_el_is_aa64(env, 3)) {
>> -                return 3;
>> -            }
>> -            return 1;
>> -        }
>> -        if (cur_el == 3 && !is_a64(env)) {
>> -            /* Secure PL1 running at EL3 */
>> -            return 3;
>> -        }
>> -        break;
>> -    case 1:
>> -        if (cur_el == 0) {
>> -            return 1;
>> -        }
>> -        break;
>> -    case 3:
>> -        break;
>> -    }
>> -
>> -    /* For the CPTR registers we don't need to guard with an ARM_FEATURE
>> -     * check because zero bits in the registers mean "don't trap".
>> -     */
>> -
>> -    /* CPTR_EL2 : present in v7VE or v8 */
>> -    if (cur_el <= 2 && extract32(env->cp15.cptr_el[2], 10, 1)
>> -        && !arm_is_secure_below_el3(env)) {
>> -        /* Trap FP ops at EL2, NS-EL1 or NS-EL0 to EL2 */
>> -        return 2;
>> -    }
>> -
>> -    /* CPTR_EL3 : present in v8 */
>> -    if (extract32(env->cp15.cptr_el[3], 10, 1)) {
>> -        /* Trap all FP ops to EL3 */
>> -        return 3;
>> -    }
>> -
>> -    return 0;
>> -}
>> -
>>  #ifdef CONFIG_USER_ONLY
>>  static inline bool arm_cpu_bswap_data(CPUARMState *env)
>>  {
>> @@ -2814,66 +2749,8 @@ static inline uint32_t arm_regime_tbi1(CPUARMState *env, ARMMMUIdx mmu_idx)
>>  }
>>  #endif
>>
>> -static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
>> -                                        target_ulong *cs_base, uint32_t *flags)
>> -{
>> -    ARMMMUIdx mmu_idx = core_to_arm_mmu_idx(env, cpu_mmu_index(env, false));
>> -    if (is_a64(env)) {
>> -        *pc = env->pc;
>> -        *flags = ARM_TBFLAG_AARCH64_STATE_MASK;
>> -        /* Get control bits for tagged addresses */
>> -        *flags |= (arm_regime_tbi0(env, mmu_idx) << ARM_TBFLAG_TBI0_SHIFT);
>> -        *flags |= (arm_regime_tbi1(env, mmu_idx) << ARM_TBFLAG_TBI1_SHIFT);
>> -    } else {
>> -        *pc = env->regs[15];
>> -        *flags = (env->thumb << ARM_TBFLAG_THUMB_SHIFT)
>> -            | (env->vfp.vec_len << ARM_TBFLAG_VECLEN_SHIFT)
>> -            | (env->vfp.vec_stride << ARM_TBFLAG_VECSTRIDE_SHIFT)
>> -            | (env->condexec_bits << ARM_TBFLAG_CONDEXEC_SHIFT)
>> -            | (arm_sctlr_b(env) << ARM_TBFLAG_SCTLR_B_SHIFT);
>> -        if (!(access_secure_reg(env))) {
>> -            *flags |= ARM_TBFLAG_NS_MASK;
>> -        }
>> -        if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30)
>> -            || arm_el_is_aa64(env, 1)) {
>> -            *flags |= ARM_TBFLAG_VFPEN_MASK;
>> -        }
>> -        *flags |= (extract32(env->cp15.c15_cpar, 0, 2)
>> -                   << ARM_TBFLAG_XSCALE_CPAR_SHIFT);
>> -    }
>> -
>> -    *flags |= (arm_to_core_mmu_idx(mmu_idx) << ARM_TBFLAG_MMUIDX_SHIFT);
>> -
>> -    /* The SS_ACTIVE and PSTATE_SS bits correspond to the state machine
>> -     * states defined in the ARM ARM for software singlestep:
>> -     *  SS_ACTIVE   PSTATE.SS   State
>> -     *     0            x       Inactive (the TB flag for SS is always 0)
>> -     *     1            0       Active-pending
>> -     *     1            1       Active-not-pending
>> -     */
>> -    if (arm_singlestep_active(env)) {
>> -        *flags |= ARM_TBFLAG_SS_ACTIVE_MASK;
>> -        if (is_a64(env)) {
>> -            if (env->pstate & PSTATE_SS) {
>> -                *flags |= ARM_TBFLAG_PSTATE_SS_MASK;
>> -            }
>> -        } else {
>> -            if (env->uncached_cpsr & PSTATE_SS) {
>> -                *flags |= ARM_TBFLAG_PSTATE_SS_MASK;
>> -            }
>> -        }
>> -    }
>> -    if (arm_cpu_data_is_big_endian(env)) {
>> -        *flags |= ARM_TBFLAG_BE_DATA_MASK;
>> -    }
>> -    *flags |= fp_exception_el(env) << ARM_TBFLAG_FPEXC_EL_SHIFT;
>> -
>> -    if (arm_v7m_is_handler_mode(env)) {
>> -        *flags |= ARM_TBFLAG_HANDLER_MASK;
>> -    }
>> -
>> -    *cs_base = 0;
>> -}
>> +void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
>> +                          target_ulong *cs_base, uint32_t *flags);
>>
>>  enum {
>>      QEMU_PSCI_CONDUIT_DISABLED = 0,
>> diff --git a/target/arm/helper.c b/target/arm/helper.c
>> index 984a4b1306..9e673bb672 100644
>> --- a/target/arm/helper.c
>> +++ b/target/arm/helper.c
>> @@ -11701,3 +11701,129 @@ uint32_t HELPER(crc32c)(uint32_t acc, uint32_t val, uint32_t bytes)
>>      /* Linux crc32c converts the output to one's complement.  */
>>      return crc32c(acc, buf, bytes) ^ 0xffffffff;
>>  }
>> +
>> +/* Return the exception level to which FP-disabled exceptions should
>> + * be taken, or 0 if FP is enabled.
>> + */
>> +static inline int fp_exception_el(CPUARMState *env)
> 
> You can drop the inline here. The compiler knows what to do and we are
> no longer in a header.
> 
>> +{
>> +    int fpen;
>> +    int cur_el = arm_current_el(env);
>> +
>> +    /* CPACR and the CPTR registers don't exist before v6, so FP is
>> +     * always accessible
>> +     */
>> +    if (!arm_feature(env, ARM_FEATURE_V6)) {
>> +        return 0;
>> +    }
>> +
>> +    /* The CPACR controls traps to EL1, or PL1 if we're 32 bit:
>> +     * 0, 2 : trap EL0 and EL1/PL1 accesses
>> +     * 1    : trap only EL0 accesses
>> +     * 3    : trap no accesses
>> +     */
>> +    fpen = extract32(env->cp15.cpacr_el1, 20, 2);
>> +    switch (fpen) {
>> +    case 0:
>> +    case 2:
>> +        if (cur_el == 0 || cur_el == 1) {
>> +            /* Trap to PL1, which might be EL1 or EL3 */
>> +            if (arm_is_secure(env) && !arm_el_is_aa64(env, 3)) {
>> +                return 3;
>> +            }
>> +            return 1;
>> +        }
>> +        if (cur_el == 3 && !is_a64(env)) {
>> +            /* Secure PL1 running at EL3 */
>> +            return 3;
>> +        }
>> +        break;
>> +    case 1:
>> +        if (cur_el == 0) {
>> +            return 1;
>> +        }
>> +        break;
>> +    case 3:
>> +        break;
>> +    }
>> +
>> +    /* For the CPTR registers we don't need to guard with an ARM_FEATURE
>> +     * check because zero bits in the registers mean "don't trap".
>> +     */
>> +
>> +    /* CPTR_EL2 : present in v7VE or v8 */
>> +    if (cur_el <= 2 && extract32(env->cp15.cptr_el[2], 10, 1)
>> +        && !arm_is_secure_below_el3(env)) {
>> +        /* Trap FP ops at EL2, NS-EL1 or NS-EL0 to EL2 */
>> +        return 2;
>> +    }
>> +
>> +    /* CPTR_EL3 : present in v8 */
>> +    if (extract32(env->cp15.cptr_el[3], 10, 1)) {
>> +        /* Trap all FP ops to EL3 */
>> +        return 3;
>> +    }
>> +
>> +    return 0;
>> +}
> 
> I'm not sure helper.c is the best place for this. Maybe cpu.c?

Because sve_exception_el will also be used for protecting access to the SVE
system registers, all of which are defined here in helper.c.


r~