Messages in this thread | | | Subject | Re: [PATCH v4 02/26] arm64: cpufeature: Add cpufeature for IRQ priority masking | From | Suzuki K Poulose <> | Date | Fri, 25 May 2018 11:41:51 +0100 |
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On 25/05/18 11:39, Julien Thierry wrote: > > > On 25/05/18 11:36, Suzuki K Poulose wrote: >> On 25/05/18 11:17, Julien Thierry wrote: >>> >>> >>> On 25/05/18 11:04, Suzuki K Poulose wrote: >>>> On 25/05/18 10:49, Julien Thierry wrote: >>>>> Add a cpufeature indicating whether a cpu supports masking interrupts >>>>> by priority. >>>> >>>> How is this different from the SYSREG_GIC_CPUIF cap ? Is it just >>>> the description ? >>> >>> More or less. >>> >>> It is just to have an easier condition in the rest of the series. Basically the PRIO masking feature is enabled if we have a GICv3 CPUIF working *and* the option was selected at build time. Before this meant that I was checking for the GIC_CPUIF cap inside #ifdefs (and putting alternatives depending on that inside #ifdefs as well). >>> >>> Having this as a separate feature feels easier to manage in the code. It also makes it clearer at boot time that the kernel will be using irq priorities (although I admit it was not the initial intention): >>> >>> [ 0.000000] CPU features: detected: IRQ priority masking >>> >>> >>> But yes that new feature will be detected only if SYSREG_GIC_CPUIF gets detected as well. >> >> Well, you could always wrap the check like : >> >> static inline bool system_has_irq_priority_masking(void) >> { >> return (IS_ENABLED(CONFIG_YOUR_CONFIG) && cpus_have_const_cap(HWCAP_SYSREG_GIC_CPUIF)); >> } >> >> and use it everywhere. >> > > Yes, but I can't use that in the asm parts that use alternatives and would need to surround them in #ifdef... :\
I thought there is _ALTERNATIVE_CFG() to base the alternative depend on a CONFIG_xxx ? Doesn't that solve the problem ?
Suzuki
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