iommu coherency

In dmar_domain, more than one iommus may be included in iommu_bmp. Due to "Coherency" capability may be different across iommus, set this variable to indicate iommu access is coherent or not. Only when all related iommus in a dmar_domain are all coherent, iommu access of this domain is coherent.

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 3ecfa2304c2c..104e99df2ade 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -221,6 +221,8 @@ struct dmar_domain {
         int             agaw;
 
         int             flags;          /* flags to find out type of domain */
+
+        int             iommu_coherency;/* indicate coherency of iommu access */
 };
 
 /* PCI domain-device relationship */
@@ -396,6 +398,23 @@ static struct intel_iommu *domain_get_iommu(struct dmar_domain *domain)
         return g_iommus[iommu_id];
 }
 
+/* "Coherency" capability may be different across iommus */
+static void domain_update_iommu_coherency(struct dmar_domain *domain)
+{
+        int i;
+
+        domain->iommu_coherency = 1;
+
+        i = find_first_bit(&domain->iommu_bmp, g_num_of_iommus);
+        for (; i < g_num_of_iommus; ) {
+                if (!ecap_coherent(g_iommus[i]->ecap)) {
+                        domain->iommu_coherency = 0;
+                        break;
+                }
+                i = find_next_bit(&domain->iommu_bmp, g_num_of_iommus, i+1);
+        }
+}
+
 /* Gets context entry for a given bus and devfn */
 static struct context_entry * device_to_context_entry(struct intel_iommu *iommu,
                 u8 bus, u8 devfn)
@@ -1346,6 +1365,11 @@ static int domain_init(struct dmar_domain *domain, int guest_width)
         domain->agaw = agaw;
         INIT_LIST_HEAD(&domain->devices);
 
+        if (ecap_coherent(iommu->ecap))
+                domain->iommu_coherency = 1;
+        else
+                domain->iommu_coherency = 0;
+
         /* always allocate the top pgd */
         domain->pgd = (struct dma_pte *)alloc_pgtable_page();
         if (!domain->pgd)