Re: [PATCH v3 05/10] arm/cpu: accessors for writable id registers

[Cornelia Huck <cohuck@redhat.com>]

On Tue, Apr 29 2025, Sebastian Ott <sebott@redhat.com> wrote:

> On Mon, 14 Apr 2025, Cornelia Huck wrote:
>> Also add conversion between the different indices.
>>
>> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>> target/arm/cpu.h | 18 ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
>> index bbee7ff2414a..775a8aebc5d3 100644
>> --- a/target/arm/cpu.h
>> +++ b/target/arm/cpu.h
>> @@ -876,6 +876,13 @@ typedef struct IdRegMap {
>>     uint64_t regs[NR_ID_REGS];
>> } IdRegMap;
>>
>> +#define ARM_FEATURE_ID_RANGE_IDX(op0, op1, crn, crm, op2)               \
>> +        ({                                                              \
>> +                __u64 __op1 = (op1) & 3;                                \
>> +                __op1 -= (__op1 == 3);                                  \
>> +                (__op1 << 6 | ((crm) & 7) << 3 | (op2));                \
>> +        })
>> +
>> /* REG is ID_XXX */
>> #define FIELD_DP64_IDREG(ISAR, REG, FIELD, VALUE)                       \
>>     ({                                                                  \
>> @@ -923,6 +930,17 @@ typedef struct IdRegMap {
>>         i_->idregs[REG ## _EL1_IDX];                                    \
>>     })
>>
>> +#define GET_IDREG_WRITABLE(MAP, REG)                                  \
>> +    ({                                                                \
>> +    const IdRegMap *m_ = (MAP);                                       \
>> +    int index = ARM_FEATURE_ID_RANGE_IDX((sysreg >> 14) & 0x0000c000, \
>> +                                         (sysreg >> 11) & 0x00003800, \
>> +                                         (sysreg >> 7) & 0x00000780,  \
>> +                                         (sysreg >> 3) & 0x00000078,  \
>> +                                         sysreg & 0x00000007);        \
>> +    m_->regs[index];                                                  \
>> +    })
>> +
>
> s/sysreg/REG/
>
> Also GET_IDREG_WRITABLE doesn't seem to be used in this series.

Hm, and it wouldn't have worked if we did use it... probably an artifact
left over from earlier refactorings, I think we can get rid of it.