Re: [Xen-devel] [PATCH 3/4] xen: arm: add barrier before sev in smp_spin_table_cpu_up

[Julien Grall <julien.grall@xxxxxxxxxx>]

Hi Ian,

On 03/17/2014 01:52 PM, Ian Campbell wrote:
> This ensures that the writeq to the release address has occurred.
> 
> In reality there is a dsb() in the iounmap() (in the eventual write_pte()) but
> make it explicit.

There other place (see xen/arch/arm/platforms/exynos5.c) where we rely
on the dsb in write_pte. I think we should move the dsb in iounmap().

> 
> The ARMv8 ARM recommends that sev() is usually accompanied by a dsb(), the
> only other uses are in the v7 spinlock code which includes a dsb() already.

Would it be better to add dsb in the sev() macro?

Regards,

-- 
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel