[U-Boot] [PATCH v3 3/5] ls102xa: HYP/non-sec: support for ls102xa boards

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hello Li.Xiubo at freescale.com,

On Fri, 14 Nov 2014 09:06:13 +0000, Li.Xiubo at freescale.com
<Li.Xiubo@freescale.com> wrote:
> Hi Albert,
> 
> > > +#if defined(CONFIG_ARMV7_NONSEC) || defined(CONFIG_ARMV7_VIRT)
> > > +/* Setting the address at which secondary cores start from.*/
> > > +void smp_set_core_boot_addr(unsigned long addr, int corenr)
> > > +{
> > > +	struct ccsr_gur __iomem *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
> > > +
> > > +	/*
> > > +	 * After setting the secondary cores start address,
> > > +	 * just release them to boot.
> > > +	 */
> > > +	out_be32(&gur->scratchrw[0], addr);
> > > +	out_be32(&gur->brrl, 0x2);
> > > +}
> > 
> > This function does not exactly "[set] the address at which secondary
> > cores start from"; it sets *a* secondary core's boot address, and then
> > it *boots* it.
> > 
> 
> Okay, I will fix it later.
> 
> > Why does this version of smp_set_core_boot_addr() need to boot the core
> > in addition to setting the address, whereas the existing ones in
> > virt_v7, vexpress_common and arndale don't boot the cores?
> > 
> 
> Yes, they don't doing the release operation.
> 
> For Low Power Management requirement, maybe only one core will be used, and then
> We also make sure that the secondary core must be in low power and deep sleep
> mode(using wfi). So I just release it here, to make sure that the wfi instruction
> will be executed as early as possible.

Right after smp_set_core_boot_addr() is called, kick_all_cpus() isgoing
to be called. Wouldn't that boot your CPUs just as well?

> Thanks,
> 
> BRs,
> Xiubo

Amicalement,
-- 
Albert.