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>

diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h
index ab3e7bf..e68b148 100644 (file)
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -238,7 +238,9 @@ struct protection_domain {
        unsigned long flags;    /* flags to find out type of domain */
        bool updated;           /* complete domain flush required */
        unsigned dev_cnt;       /* devices assigned to this domain */
+       unsigned dev_iommu[MAX_IOMMUS]; /* per-IOMMU reference count */
        void *priv;             /* private data */
+
 };
 
 /*

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 7fe28be..8c38f00 100644 (file)
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1175,7 +1175,9 @@ static void __attach_device(struct amd_iommu *iommu,
        /* 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 attach_device(struct amd_iommu *iommu,
  */
 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 @@ static void __detach_device(struct protection_domain *domain, u16 devid)
 
        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);