diff options
Diffstat (limited to 'drivers/pci/dmar.c')
| -rw-r--r-- | drivers/pci/dmar.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index bb4ed985f9c..932e5e3930f 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -754,6 +754,42 @@ int qi_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr, } /* + * Disable Queued Invalidation interface. + */ +void dmar_disable_qi(struct intel_iommu *iommu) +{ + unsigned long flags; + u32 sts; + cycles_t start_time = get_cycles(); + + if (!ecap_qis(iommu->ecap)) + return; + + spin_lock_irqsave(&iommu->register_lock, flags); + + sts = dmar_readq(iommu->reg + DMAR_GSTS_REG); + if (!(sts & DMA_GSTS_QIES)) + goto end; + + /* + * Give a chance to HW to complete the pending invalidation requests. + */ + while ((readl(iommu->reg + DMAR_IQT_REG) != + readl(iommu->reg + DMAR_IQH_REG)) && + (DMAR_OPERATION_TIMEOUT > (get_cycles() - start_time))) + cpu_relax(); + + iommu->gcmd &= ~DMA_GCMD_QIE; + + writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG); + + IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, + !(sts & DMA_GSTS_QIES), sts); +end: + spin_unlock_irqrestore(&iommu->register_lock, flags); +} + +/* * Enable Queued Invalidation interface. This is a must to support * interrupt-remapping. Also used by DMA-remapping, which replaces * register based IOTLB invalidation. |