On 2 April 2014 18:42, Rob Herring robherring2@gmail.com wrote:
On Wed, Apr 2, 2014 at 5:42 AM, Anup Patel anup.patel@linaro.org wrote:
As-per PSCI v0.2, the source CPU provides physical address of "entry point" and "context id" for starting a target CPU. Also, if target CPU is already running then we should return ALREADY_ON.
Current emulation of CPU_ON function does not consider physical address of "context id" and returns INVALID_PARAMETERS if target CPU is already running.
This patch updates kvm_psci_vcpu_on() such that it works for both PSCI v0.1 and PSCI v0.2.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org
arch/arm/kvm/psci.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index d8335da..fdbd829 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c
@@ -101,6 +109,8 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) kvm_vcpu_set_be(vcpu);
*vcpu_pc(vcpu) = target_pc;
if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)*vcpu_reg(vcpu, 0) = context_id;This could be done unconditionally. The register value is undefined for 0.1, so whatever was in r3/x3 meets that requirement.
I had similar thought when I first updated this but then I was not sure if PSCI v0.1 assumes this register to be undefined.
Let me update this unconditionally as-per your suggestion and put a comment here.
Rob
-- Anup