[PATCH 04/10] KVM: arm/arm64: vgic: Allow HW irq to be encoded in LR

[Marc Zyngier]

On 09/06/15 14:21, Alex Bennée wrote:
> 
> Marc Zyngier <marc.zyngier at arm.com> writes:
> 
>> Now that struct vgic_lr supports the LR_HW bit and carries a hwirq
>> field, we can encode that information into the list registers.
>>
>> This patch provides implementations for both GICv2 and GICv3.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
>> ---
>>  include/linux/irqchip/arm-gic-v3.h |  3 +++
>>  include/linux/irqchip/arm-gic.h    |  3 ++-
>>  virt/kvm/arm/vgic-v2.c             | 16 +++++++++++++++-
>>  virt/kvm/arm/vgic-v3.c             | 21 ++++++++++++++++++---
>>  4 files changed, 38 insertions(+), 5 deletions(-)
>>
>> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
>> index ffbc034..cf637d6 100644
> <snip>
>> @@ -84,10 +88,17 @@ static void vgic_v3_set_lr(struct kvm_vcpu *vcpu, int lr,
>>  	 * Eventually we want to make this configurable, so we may revisit
>>  	 * this in the future.
>>  	 */
>> -	if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
>> +	switch (vcpu->kvm->arch.vgic.vgic_model) {
>> +	case KVM_DEV_TYPE_ARM_VGIC_V3:
>>  		lr_val |= ICH_LR_GROUP;
>> -	else
>> -		lr_val |= (u32)lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT;
>> +		break;
>> +	case  KVM_DEV_TYPE_ARM_VGIC_V2:
>> +		if (lr_desc.irq < VGIC_NR_SGIS)
>> +			lr_val |= (u32)lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT;
>> +		break;
>> +	default:
>> +		BUG();
>> +	}
>>  
>>  	if (lr_desc.state & LR_STATE_PENDING)
>>  		lr_val |= ICH_LR_PENDING_BIT;
>> @@ -95,6 +106,10 @@ static void vgic_v3_set_lr(struct kvm_vcpu *vcpu, int lr,
>>  		lr_val |= ICH_LR_ACTIVE_BIT;
>>  	if (lr_desc.state & LR_EOI_INT)
>>  		lr_val |= ICH_LR_EOI;
>> +	if (lr_desc.state & LR_HW) {
>> +		lr_val |= ICH_LR_HW;
>> +		lr_val |= ((u64)lr_desc.hwirq) << ICH_LR_PHYS_ID_SHIFT;
>> +	}
>>
> 
> Why is the bracketing different for the casting of lr_desc.hwirq
> compared to lr_desc.source. Surely the precedence of up-casting before
> the shift is the same in both cases?

Probably a leftover from a previous refactor...

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...