From eb4a52bc660ea835482c582eaaf4893742cbd160 Mon Sep 17 00:00:00 2001 From: Fenghua Yu Date: Fri, 27 Mar 2009 14:22:43 -0700 Subject: [PATCH] Intel IOMMU Suspend/Resume Support - Queued Invalidation This patch supports queued invalidation suspend/resume. Signed-off-by: Fenghua Yu Acked-by: Ingo Molnar Signed-off-by: David Woodhouse --- drivers/pci/dmar.c | 70 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 55 insertions(+), 15 deletions(-) diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index d313039e2fd..3fbe6af7ad7 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -789,6 +789,35 @@ end: spin_unlock_irqrestore(&iommu->register_lock, flags); } +/* + * Enable queued invalidation. + */ +static void __dmar_enable_qi(struct intel_iommu *iommu) +{ + u32 cmd, sts; + unsigned long flags; + struct q_inval *qi = iommu->qi; + + qi->free_head = qi->free_tail = 0; + qi->free_cnt = QI_LENGTH; + + spin_lock_irqsave(&iommu->register_lock, flags); + + /* write zero to the tail reg */ + writel(0, iommu->reg + DMAR_IQT_REG); + + dmar_writeq(iommu->reg + DMAR_IQA_REG, virt_to_phys(qi->desc)); + + cmd = iommu->gcmd | DMA_GCMD_QIE; + iommu->gcmd |= DMA_GCMD_QIE; + writel(cmd, iommu->reg + DMAR_GCMD_REG); + + /* Make sure hardware complete it */ + IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts); + + 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 @@ -796,8 +825,6 @@ end: */ int dmar_enable_qi(struct intel_iommu *iommu) { - u32 cmd, sts; - unsigned long flags; struct q_inval *qi; if (!ecap_qis(iommu->ecap)) @@ -835,19 +862,7 @@ int dmar_enable_qi(struct intel_iommu *iommu) spin_lock_init(&qi->q_lock); - spin_lock_irqsave(&iommu->register_lock, flags); - /* write zero to the tail reg */ - writel(0, iommu->reg + DMAR_IQT_REG); - - dmar_writeq(iommu->reg + DMAR_IQA_REG, virt_to_phys(qi->desc)); - - cmd = iommu->gcmd | DMA_GCMD_QIE; - iommu->gcmd |= DMA_GCMD_QIE; - writel(cmd, iommu->reg + DMAR_GCMD_REG); - - /* Make sure hardware complete it */ - IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts); - spin_unlock_irqrestore(&iommu->register_lock, flags); + __dmar_enable_qi(iommu); return 0; } @@ -1102,3 +1117,28 @@ int __init enable_drhd_fault_handling(void) return 0; } + +/* + * Re-enable Queued Invalidation interface. + */ +int dmar_reenable_qi(struct intel_iommu *iommu) +{ + if (!ecap_qis(iommu->ecap)) + return -ENOENT; + + if (!iommu->qi) + return -ENOENT; + + /* + * First disable queued invalidation. + */ + dmar_disable_qi(iommu); + /* + * Then enable queued invalidation again. Since there is no pending + * invalidation requests now, it's safe to re-enable queued + * invalidation. + */ + __dmar_enable_qi(iommu); + + return 0; +} -- 2.41.1