Their calculations of the value to write to the respective command register can be partly folded, resulting in almost 100 bytes less code for these two relatively short functions.
Signed-off-by: Jan Beulich <[email protected]> --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -441,7 +441,6 @@ int vtd_flush_context_reg(struct vtd_iom uint16_t source_id, uint8_t function_mask, uint64_t type, bool flush_non_present_entry) { - u64 val = 0; unsigned long flags; /* @@ -462,26 +461,26 @@ int vtd_flush_context_reg(struct vtd_iom switch ( type ) { case DMA_CCMD_GLOBAL_INVL: - val = DMA_CCMD_GLOBAL_INVL; - break; - case DMA_CCMD_DOMAIN_INVL: - val = DMA_CCMD_DOMAIN_INVL|DMA_CCMD_DID(did); break; + case DMA_CCMD_DEVICE_INVL: - val = DMA_CCMD_DEVICE_INVL|DMA_CCMD_DID(did) - |DMA_CCMD_SID(source_id)|DMA_CCMD_FM(function_mask); + type |= DMA_CCMD_SID(source_id) | DMA_CCMD_FM(function_mask); + fallthrough; + case DMA_CCMD_DOMAIN_INVL: + type |= DMA_CCMD_DID(did); break; + default: BUG(); } - val |= DMA_CCMD_ICC; + type |= DMA_CCMD_ICC; spin_lock_irqsave(&iommu->register_lock, flags); - dmar_writeq(iommu->reg, DMAR_CCMD_REG, val); + dmar_writeq(iommu->reg, DMAR_CCMD_REG, type); /* Make sure hardware complete it */ IOMMU_FLUSH_WAIT("context", iommu, DMAR_CCMD_REG, dmar_readq, - !(val & DMA_CCMD_ICC), val); + !(type & DMA_CCMD_ICC), type); spin_unlock_irqrestore(&iommu->register_lock, flags); /* flush context entry will implicitly flush write buffer */ @@ -510,7 +509,7 @@ int vtd_flush_iotlb_reg(struct vtd_iommu bool flush_non_present_entry, bool flush_dev_iotlb) { int tlb_offset = ecap_iotlb_offset(iommu->ecap); - u64 val = 0; + uint64_t val = type | DMA_TLB_IVT; unsigned long flags; /* @@ -524,14 +523,13 @@ int vtd_flush_iotlb_reg(struct vtd_iommu switch ( type ) { case DMA_TLB_GLOBAL_FLUSH: - val = DMA_TLB_GLOBAL_FLUSH|DMA_TLB_IVT; break; + case DMA_TLB_DSI_FLUSH: - val = DMA_TLB_DSI_FLUSH|DMA_TLB_IVT|DMA_TLB_DID(did); - break; case DMA_TLB_PSI_FLUSH: - val = DMA_TLB_PSI_FLUSH|DMA_TLB_IVT|DMA_TLB_DID(did); + val |= DMA_TLB_DID(did); break; + default: BUG(); }
