Re: [PATCH 2/5] irqchip/gic-v3: Make gic_enable_sre an inline function
From: Marc Zyngier
Date: Thu Oct 08 2015 - 12:02:34 EST
On 08/10/15 16:54, Catalin Marinas wrote:
> On Fri, Oct 02, 2015 at 05:37:51PM +0100, Marc Zyngier wrote:
>> +static inline bool gic_enable_sre(void)
>> +{
>> + u64 val;
>> +
>> + asm volatile("mrs_s %0, " __stringify(ICC_SRE_EL1) : "=r" (val));
>> + if (val & ICC_SRE_EL1_SRE)
>> + return true;
>> +
>> + val |= ICC_SRE_EL1_SRE;
>> + asm volatile("msr_s " __stringify(ICC_SRE_EL1) ", %0" : : "r" (val));
>> + isb();
>> + asm volatile("mrs_s %0, " __stringify(ICC_SRE_EL1) : "=r" (val));
>> +
>> + return !!(val & ICC_SRE_EL1_SRE);
>> +}
>
> I don't think !! is needed ;). Apparently, from ISO C99: "When any
> scalar value is converted to _Bool, the result is 0 if the value
> compares equal to 0; otherwise, the result is 1."
Are you going to break my fingers? ;-)
>From my very own PoV, !! acts as a reminder that I have realised what
the return type is. Yeah, that's how bad my brain is these days :-)
M.
--
Jazz is not dead. It just smells funny...
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