Re: [PATCH 1/2] xen/arm: Simplify SMCCC handling by reusing __declare_arg_$()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 24/02/2026 2:17 pm, Andrew Cooper wrote:
> On 24/02/2026 2:14 pm, Orzel, Michal wrote:
>> On 24/02/2026 13:45, Andrew Cooper wrote:
>>> Now that the type handling is entirely uniform, it's easier to see that
>>> __declare_arg_3() can use __declare_arg_2() and so on, just like the larger
>>> __declare_arg_$()'s already do.
>>>
>>> No functional change.
>> This patch won't build.
>>
>>> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
>>> ---
>>> CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
>>> CC: Julien Grall <julien@xxxxxxx>
>>> CC: Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
>>> CC: Bertrand Marquis <bertrand.marquis@xxxxxxx>
>>> CC: Michal Orzel <michal.orzel@xxxxxxx>
>>> ---
>>>  xen/arch/arm/include/asm/smccc.h | 15 +++------------
>>>  1 file changed, 3 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/xen/arch/arm/include/asm/smccc.h 
>>> b/xen/arch/arm/include/asm/smccc.h
>>> index 5b30dd57b69d..347c4526d12a 100644
>>> --- a/xen/arch/arm/include/asm/smccc.h
>>> +++ b/xen/arch/arm/include/asm/smccc.h
>>> @@ -114,26 +114,17 @@ struct arm_smccc_res {
>>>  
>>>  #define __declare_arg_1(a0, a1, res)                        \
>>>      typeof(a1) __a1 = (a1);                                 \
>>> -    struct arm_smccc_res    *___res = (res);                \
>>> -    register unsigned long  arg0 ASM_REG(0) = (uint32_t)(a0);\
>>> +    __declare_arg_0(a0, res);                               \
>>>      register typeof(a1)     arg1 ASM_REG(1) = __a1
>>>  
>>>  #define __declare_arg_2(a0, a1, a2, res)                    \
>>>      typeof(a1) __a1 = (a1);                                 \
>> You should remove this line and ...
>>
>>> -    typeof(a2) __a2 = (a2);                                 \
>> keep this line.
>>
>>> -    struct arm_smccc_res    *___res = (res);                \
>>> -    register unsigned long  arg0 ASM_REG(0) = (uint32_t)(a0);\
>>> -    register typeof(a1)     arg1 ASM_REG(1) = __a1;         \
>>> +    __declare_arg_1(a0, a1, res);                           \
>>>      register typeof(a2)     arg2 ASM_REG(2) = __a2
>>>  
>>>  #define __declare_arg_3(a0, a1, a2, a3, res)                \
>>>      typeof(a1) __a1 = (a1);                                 \
>>> -    typeof(a2) __a2 = (a2);                                 \
>> Same here.
> Hmm - it built for me.  I'd better figure out why I missed it first.

Ah - a last minute refactor, and I didn't build test on this commit
boundary.

Fixed.  Thanks.

~Andrew