On 21 January 2016 at 18:51, Mark Rutland <mark.rutl...@arm.com> wrote: > On Thu, Jan 21, 2016 at 04:48:57PM +0800, Zhaoyang Huang wrote: >> Hi Mark, > > Hi, > >> Do you have any suggestion on how to sync the GIC operation from >> kernel and psci parallelly? Thanks! > > I'm not sure what you mean. > > What problem are you having with synchronising GIC accesses? > > As far as I can see, the CPU sending the IPI can simply poke the > relevant register in the distributor without requiring any > synchronisation. The CPU receiving the IPI is the only CPU with access > to its CPU interface. > > Could you describe your problem in more detail? > > Thanks, > Mark. > Hi Mark, Sorry for making confusions. I mean mutex between kernel and trustzone when accessing GIC registers. It is possible for they two issuing an accessing to the same register at the same time. How should I handle such kind of race conditions?
>> On 12 January 2016 at 19:51, Mark Rutland <mark.rutl...@arm.com> 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.hu...@linaro.org> >> >> > 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. >>
