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>

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 3ecfa23..104e99d 100644 (file)
--- 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)