Impact: add helper functions to detach a device from a domain

Signed-off-by: Joerg Roedel <[EMAIL PROTECTED]>
---
 arch/x86/kernel/amd_iommu.c |   41 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 41 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 61584d5..47158e3 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1469,3 +1469,44 @@ free_domains:
 
        return ret;
 }
+
+/*****************************************************************************
+ *
+ * The following functions belong to the exported interface of AMD IOMMU
+ *
+ * This interface allows access to lower level functions of the IOMMU
+ * like protection domain handling and assignement of devices to domains
+ * which is not possible with the dma_ops interface.
+ *
+ *****************************************************************************/
+
+static void __detach_device(struct protection_domain *domain, u16 devid)
+{
+
+       /* lock domain */
+       spin_lock(&domain->lock);
+
+       /* remove domain from the lookup table */
+       amd_iommu_pd_table[devid] = NULL;
+
+       /* remove entry from the device table seen by the hardware */
+       amd_iommu_dev_table[devid].data[0] = IOMMU_PTE_P | IOMMU_PTE_TV;
+       amd_iommu_dev_table[devid].data[1] = 0;
+       amd_iommu_dev_table[devid].data[2] = 0;
+
+       /* decrease reference counter */
+       domain->dev_cnt -= 1;
+
+       /* ready */
+       spin_unlock(&domain->lock);
+}
+
+static void detach_device(struct protection_domain *domain, u16 devid)
+{
+       unsigned long flags;
+
+       /* lock device table */
+       write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+       __detach_device(domain, devid);
+       write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+}
-- 
1.5.6.4


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