diff options
| author | Marc Zyngier <marc.zyngier@arm.com> | 2014-07-12 14:24:00 +0100 |
|---|---|---|
| committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2014-07-28 17:06:28 +0200 |
| commit | 64fd44dcae0daafb011f98d4b2d4e1f28036b99e (patch) | |
| tree | 8248f7a20fe05be8e87dac0987b00841f8b3ce7f /arch/arm/cpu/armv7/nonsec_virt.S | |
| parent | 800c83522ca6a7d6fd0b058f423501b4cc52d6d6 (diff) | |
ARM: non-sec: reset CNTVOFF to zero
Before switching to non-secure, make sure that CNTVOFF is set
to zero on all CPUs. Otherwise, kernel running in non-secure
without HYP enabled (hence using virtual timers) may observe
timers that are not synchronized, effectively seeing time
going backward...
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
Diffstat (limited to 'arch/arm/cpu/armv7/nonsec_virt.S')
| -rw-r--r-- | arch/arm/cpu/armv7/nonsec_virt.S | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/arm/cpu/armv7/nonsec_virt.S b/arch/arm/cpu/armv7/nonsec_virt.S index 12de5c2d17..b5c946fc4e 100644 --- a/arch/arm/cpu/armv7/nonsec_virt.S +++ b/arch/arm/cpu/armv7/nonsec_virt.S @@ -38,10 +38,10 @@ _secure_monitor: bic r1, r1, #0x4e @ clear IRQ, FIQ, EA, nET bits orr r1, r1, #0x31 @ enable NS, AW, FW bits -#ifdef CONFIG_ARMV7_VIRT mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1 and r0, r0, #CPUID_ARM_VIRT_MASK @ mask virtualization bits cmp r0, #(1 << CPUID_ARM_VIRT_SHIFT) +#ifdef CONFIG_ARMV7_VIRT orreq r1, r1, #0x100 @ allow HVC instruction #endif @@ -52,7 +52,14 @@ _secure_monitor: mrceq p15, 0, r0, c12, c0, 1 @ get MVBAR value mcreq p15, 4, r0, c12, c0, 0 @ write HVBAR #endif + bne 1f + @ Reset CNTVOFF to 0 before leaving monitor mode + mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1 + ands r0, r0, #CPUID_ARM_GENTIMER_MASK @ test arch timer bits + movne r0, #0 + mcrrne p15, 4, r0, r0, c14 @ Reset CNTVOFF to zero +1: movs pc, lr @ return to non-secure SVC _hyp_trap: |