On 2015-02-16 14:51, Mark Rutland wrote: > On Mon, Feb 16, 2015 at 01:44:36PM +0000, Jan Kiszka wrote: >> On 2015-02-16 14:37, Mark Rutland wrote: >>> On Mon, Feb 16, 2015 at 12:54:49PM +0000, Jan Kiszka wrote: >>>> We only set CNTFRQ in arch_timer_init for the boot CPU. But this has to >>>> happen for all cores. >>>> >>>> Fixing this resolves problems of KVM with emulating the generic >>>> timer/counter. >>>> >>>> Signed-off-by: Jan Kiszka <jan.kis...@siemens.com> >>>> --- >>>> arch/arm/cpu/armv7/tegra-common/psci.S | 13 +++++++++++++ >>>> 1 file changed, 13 insertions(+) >>>> >>>> diff --git a/arch/arm/cpu/armv7/tegra-common/psci.S >>>> b/arch/arm/cpu/armv7/tegra-common/psci.S >>>> index b7501fb..119c246 100644 >>>> --- a/arch/arm/cpu/armv7/tegra-common/psci.S >>>> +++ b/arch/arm/cpu/armv7/tegra-common/psci.S >>>> @@ -51,12 +51,25 @@ ENTRY(psci_arch_init) >>>> >>>> mrc p15, 0, r4, c0, c0, 5 @ MPIDR >>>> and r4, r4, #7 @ number of CPUs in cluster >>>> + >>>> + adr r5, _sys_clock_freq >>>> + cmp r4, #0 >>>> + >>>> + mrceq p15, 0, r7, c14, c0, 0 @ read CNTFRQ from CPU0 >>>> + streq r7, [r5] >>>> + >>>> + ldrne r7, [r5] >>>> + mcrne p15, 0, r7, c14, c0, 0 @ write CNTFRQ to CPU1..3 >>> >>> Is it not possible to have a hook that uses the same variable as >>> arch_timer_init rather than doing a here copy? It seems a shame to >>> duplicate the effort. >> >> The problem is related to the different address spaces. Here we run in >> the secure monitor, arch_timer_init - to my understanding - in >> non-secure mode. Didn't find a pattern so far how to transfer data (and >> that shouldn't be more complex than the above code). > > Surely arch_timer_init must be run in a secure mode in order to be > allowed to write to CNTFRQ?
Ah, right. > > If this is simply the easiest way of moving the data around then there's > no real problem with it; it's just a shame that it only happens in the > PSCI case. OK, I'll check again. Maybe it's easier than I thought. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
