[PATCH] KVM: arm64: Remove spurious semicolon in reg_to_encoding()

[Alexandru Elisei]

Hi Marc,

On 1/5/21 2:04 PM, Marc Zyngier wrote:
> On 2021-01-05 13:54, Alexandru Elisei wrote:
>> Hi Marc,
>>
>> On 12/31/20 3:09 PM, Marc Zyngier wrote:
>>> Although not a problem right now, it flared up while working
>>> on some other aspects of the code-base. Remove the useless
>>> semicolon.
>>>
>>> Signed-off-by: Marc Zyngier <maz at kernel.org>
>>> ---
>>>  arch/arm64/kvm/sys_regs.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
>>> index d46e7f706cb0..42ccc27fb684 100644
>>> --- a/arch/arm64/kvm/sys_regs.c
>>> +++ b/arch/arm64/kvm/sys_regs.c
>>> @@ -923,7 +923,7 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct
>>> sys_reg_params *p,
>>>
>>>  #define reg_to_encoding(x)                        \
>>>      sys_reg((u32)(x)->Op0, (u32)(x)->Op1,                \
>>> -        (u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2);
>>> +        (u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)
>>
>> Macro's shouldn't really end with a semicolon, otherwise code might break
>> unexpectedly:
>>
>> Reviewed-by: Alexandru Elisei <alexandru.elisei at arm.com>
>>
>> I skimmed over the code and the macro is used like a function. Do you think it's
>> worth turning it into a function to gain type checking for the
>> argument (which is
>> expected to be sys_reg_desc) and for the return value?
>
> Not quite.
>
> This macro takes indifferently a sys_reg_desc or a sys_reg_params,

Right, find_reg() calls reg_to_encoding() with a struct sys_reg_params argument, I
missed that.

Found a few instances where sys_reg() calls can be replaced with
reg_to_encoding(), will send a trivial patch for that.

Thanks,
Alex
> making it impossible to turn into a function. Is it disgusting and
> makes you want to pull your eyes out? Yes.
>
> The whole params/desc duality dates back to the early 32bit code,
> and I blame Rusty Russell for it. Just saying... ;-)
>
> That's one of things I always wanted to refactor...
>
> Thanks,
>
>         M.