On 25/05/18 11:41, Suzuki K Poulose wrote:

On 25/05/18 11:39, Julien Thierry wrote:

quoted

On 25/05/18 11:36, Suzuki K Poulose wrote:

quoted

On 25/05/18 11:17, Julien Thierry wrote:

quoted

On 25/05/18 11:04, Suzuki K Poulose wrote:

quoted

On 25/05/18 10:49, Julien Thierry wrote:

quoted

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 ?

Right, I didn't see that one. It should work yes.

I'll try that when working on the next version.

Thanks,

-- 
Julien Thierry