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
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -238,7 +238,9 @@
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
--- 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);