Hi Tamas,
On 27/01/17 16:23, Tamas K Lengyel wrote:
On Fri, Jan 27, 2017 at 9:15 AM, Julien Grall <julien.gr...@arm.com> wrote:
Hello,
On 27/01/17 15:52, Tamas K Lengyel wrote:
Well, yes, only ARM could _should_ call this function. The comment I
think is important to tell the user don't expect it to do anything on
x86. Doesn't mean they can't call it though - if that was the case it
would be wrapped in an ifdef like all the other architecture specific
bits in the header. I would think that's pretty straight forward. No
objection to clarifing the comment though if it helps.
If you looked at the commit log, the #ifdef was added to avoid calling the
hypervisor for nothing and therefore saving few hundred cycles bit of time.
Technically speaking, this helper abstracts the architectural behavior of
the cache. So it makes sense to call it on x86 even if it is a nop.
Except that on x86 the user should be aware that it returns an error,
which is normal and can be ignored.
It looks like the current callers does not check the return. However, it
would more make sense to return 0 if we expect nothing to be done rather
than -ENOSYS.
Regards,
--
Julien Grall
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