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

[Jiaxun Yang]

> 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

Thanks
- Jiaxun

> 
> I still think it is better to use property.
> 
> Thanks.
> Song Gao
>>> All references to loongarch_ipi should also be changed.
>> Sure.
>> 
>> Thanks
>> - Jiaxun
>