Re: [RFC PATCH v2] Add IPI entry for CPU UP

From: Zhaoyang Huang
Date: Thu Jan 21 2016 - 03:49:04 EST

Hi Mark,
Do you have any suggestion on how to sync the GIC operation from
kernel and psci parallelly? Thanks!

On 12 January 2016 at 19:51, Mark Rutland <mark.rutland@xxxxxxx> wrote:
> On Tue, Jan 12, 2016 at 09:38:20AM +0000, Lorenzo Pieralisi wrote:
>> On Tue, Jan 12, 2016 at 10:17:42AM +0800, Zhaoyang Huang wrote:
>> > On 12 January 2016 at 10:05, Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx> wrote:
>> > > In some ARM SOCs, IPI interrupt is used for hotplug in one cpu, that is,
>> > > sending a IPI to the core in WFI and powerdown status. So Add a IPI
>> > > entry for handle this kind of cpu up interrupt
>> > > Launching the IPI can be done within PSCI, while there will be one unknown
>> > > type of IPI as the dest core come up to the kernel world which will bring a
>> > > warning so far.So add such type of IPI to handle the interrupt.
>> You missed CC'ing ALKML for the second time and you were warned.
>> You are adding a call to *send* an IPI in the kernel so the commit
>> above is misleading.
>> Acknowledge and clear the IRQ in FW so that the mechanism is completely
>> implemented in FW (ie PSCI), that the CPU coming out of reset will run
>> before getting to the kernel, this patch is not needed and we already
>> explained to you why.
>> Lorenzo
> I would also suggest that FW used the set of SGIs reserved for secure
> usage (i.e. ID8 - ID15), as these will not conflict with those the
> kernel uses.
> Thanks,
> Mark.