summary refs log tree commit diff
path: root/drivers/pci/dmar.c
diff options
context:
space:
mode:
authorSuresh Siddha <suresh.b.siddha@intel.com>2009-03-16 17:04:56 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2009-03-17 15:39:20 -0700
commiteba67e5da6e971993b2899d2cdf459ce77d3dbc5 (patch)
tree1776415c0ed65e6ad309b6790110941fadef243f /drivers/pci/dmar.c
parent9d783ba042771284fb4ee5013c3d94220755ae7f (diff)
downloadlinux-eba67e5da6e971993b2899d2cdf459ce77d3dbc5.tar.gz
x86, dmar: routines for disabling queued invalidation and intr remapping
Impact: new interfaces (not yet used)

Routines for disabling queued invalidation and interrupt remapping.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'drivers/pci/dmar.c')
-rw-r--r--drivers/pci/dmar.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index bb4ed985f9c7..932e5e3930fc 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.