commit c459611424d8b8396060eb766e23bd0c70c993bc
author Joerg Roedel <joerg.roedel@amd.com> Fri Nov 20 14:57:32 2009 +0100
committer Joerg Roedel <joerg.roedel@amd.com> Fri Nov 27 11:45:50 2009 +0100
tree 2c15dda4d4eda490b8593aba5f29b3e1df7d2878
parent bb52777ec4d736c2d7c4f037b32d4eeeb172ed89

x86/amd-iommu: Add per IOMMU reference counting

This patch adds reference counting for protection domains
per IOMMU. This allows a smarter TLB flushing strategy.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

arch/x86/kernel/amd_iommu.c

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 7fe28be..8c38f00 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1175,7 +1175,9 @@
 	/* update DTE entry */
 	set_dte_entry(devid, domain);
 
-	domain->dev_cnt += 1;
+	/* Do reference counting */
+	domain->dev_iommu[iommu->index] += 1;
+	domain->dev_cnt                 += 1;
 
 	/* ready */
 	spin_unlock(&domain->lock);
@@ -1209,6 +1211,9 @@
  */
 static void __detach_device(struct protection_domain *domain, u16 devid)
 {
+	struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
+
+	BUG_ON(!iommu);
 
 	/* lock domain */
 	spin_lock(&domain->lock);
@@ -1223,8 +1228,9 @@
 
 	amd_iommu_apply_erratum_63(devid);
 
-	/* decrease reference counter */
-	domain->dev_cnt -= 1;
+	/* decrease reference counters */
+	domain->dev_iommu[iommu->index] -= 1;
+	domain->dev_cnt                 -= 1;
 
 	/* ready */
 	spin_unlock(&domain->lock);