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.kiszka@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?
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.
Thanks, Mark.