Re: [PATCH 1/4] hw/intc/loongarch_ipi: Bring back all 4 IPI mailboxes

[bibo, mao]

在 2023/5/23 21:07, Philippe Mathieu-Daudé 写道:
> On 23/5/23 13:18, Jiaxun Yang wrote:
>>
>>
>>> 2023年5月23日 11:01，Song Gao <gaosong@loongson.cn> 写道：
>>>
>>>
>>>
>>> 在 2023/5/23 上午11:22, Jiaxun Yang 写道:
>> [...]
>>>>
>>>>>
>>>> Is totally the same on MIPS and LoongArch. I’m guarding them out because
>>>> We have different way to get IOCSR address space on MIPS, which is due
>>>> to be implemented.
>>>>
>>>> I can further abstract out a function to get IOCSR address space. But 
>>>> still,
>>>> I think the best way to differ those two architecture is using TARGET_* 
>>>> macros,
>>>> as it doesn’t make much sense to have unused code for another architecture
>>>> compiled.
>>> Most of the code in hw/intc or hw/ uses property to distinguish between 
>>> different devices,  not TARGE_* macro.
>>
>> They are the *same* device, with different way to handle IOCSR address space.
>>
>> Another problem is casting CPUState with LOONGARCH_CPU() is something 
>> invalid on
>> MIPS, vice-versa. We are potentially introducing a security issue here.
>>
>> I know nobody have done something like this before, but not necessarily to 
>> be a bad idea.
>>
>> I’ll introduce something like:
>>
>> +#ifdef TARGET_LOONGARCH64
>> +static inline void *AddressSpace get_iocsr_as(int cpuid)
>> +{
>> +    CPUState *cs = qemu_get_cpu(cpuid);
>> +    LoongArchCPU *cpu = LOONGARCH_CPU(cs);
>> +
>> +    return &cpu->env.address_space_iocsr;
>> +}
>> +#endif
>> +
>> +#ifdef TARGET_MIPS64
>> +static inline void *AddressSpace get_iocsr_as(int cpuid)
>> +{
>> +    CPUState *cs = qemu_get_cpu(cpuid);
>> +    MIPSCPU *cpu = MIPS_CPU(cs);
>> +
>> +    return &cpu->env.iocsr.as;
>> +}
>> +#endif
> 
> Introduce a QOM interface that provides a get_iocsr_as() implementation.
> 
> See for example how TYPE_IDAU_INTERFACE works.
another simple method, rename loongarch_ipi.c with loong_ipi_common.c, adding 
extra two 
files loongarch_ipi.c and loongson_ipi.c inheriting from loong_ipi_common.c

Regards
Bibo, Mao