intel-iommu: Snooping control support
Snooping control enabled IOMMU to guarantee DMA cache coherency and thus reduce
software effort (VMM) in maintaining effective memory type.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index f3f6865..be999ff 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -231,6 +231,7 @@
int flags; /* flags to find out type of domain */
int iommu_coherency;/* indicate coherency of iommu access */
+ int iommu_snooping; /* indicate snooping control feature*/
int iommu_count; /* reference count of iommu */
spinlock_t iommu_lock; /* protect iommu set in domain */
u64 max_addr; /* maximum mapped address */
@@ -421,7 +422,6 @@
return g_iommus[iommu_id];
}
-/* "Coherency" capability may be different across iommus */
static void domain_update_iommu_coherency(struct dmar_domain *domain)
{
int i;
@@ -438,6 +438,29 @@
}
}
+static void domain_update_iommu_snooping(struct dmar_domain *domain)
+{
+ int i;
+
+ domain->iommu_snooping = 1;
+
+ i = find_first_bit(&domain->iommu_bmp, g_num_of_iommus);
+ for (; i < g_num_of_iommus; ) {
+ if (!ecap_sc_support(g_iommus[i]->ecap)) {
+ domain->iommu_snooping = 0;
+ break;
+ }
+ i = find_next_bit(&domain->iommu_bmp, g_num_of_iommus, i+1);
+ }
+}
+
+/* Some capabilities may be different across iommus */
+static void domain_update_iommu_cap(struct dmar_domain *domain)
+{
+ domain_update_iommu_coherency(domain);
+ domain_update_iommu_snooping(domain);
+}
+
static struct intel_iommu *device_to_iommu(u8 bus, u8 devfn)
{
struct dmar_drhd_unit *drhd = NULL;
@@ -1429,6 +1452,11 @@
else
domain->iommu_coherency = 0;
+ if (ecap_sc_support(iommu->ecap))
+ domain->iommu_snooping = 1;
+ else
+ domain->iommu_snooping = 0;
+
domain->iommu_count = 1;
/* always allocate the top pgd */
@@ -1557,7 +1585,7 @@
spin_lock_irqsave(&domain->iommu_lock, flags);
if (!test_and_set_bit(iommu->seq_id, &domain->iommu_bmp)) {
domain->iommu_count++;
- domain_update_iommu_coherency(domain);
+ domain_update_iommu_cap(domain);
}
spin_unlock_irqrestore(&domain->iommu_lock, flags);
return 0;
@@ -2820,7 +2848,7 @@
spin_lock_irqsave(&domain->iommu_lock, tmp_flags);
clear_bit(iommu->seq_id, &domain->iommu_bmp);
domain->iommu_count--;
- domain_update_iommu_coherency(domain);
+ domain_update_iommu_cap(domain);
spin_unlock_irqrestore(&domain->iommu_lock, tmp_flags);
}
@@ -2848,13 +2876,13 @@
iommu_detach_dev(iommu, info->bus, info->devfn);
/* clear this iommu in iommu_bmp, update iommu count
- * and coherency
+ * and capabilities
*/
spin_lock_irqsave(&domain->iommu_lock, flags2);
if (test_and_clear_bit(iommu->seq_id,
&domain->iommu_bmp)) {
domain->iommu_count--;
- domain_update_iommu_coherency(domain);
+ domain_update_iommu_cap(domain);
}
spin_unlock_irqrestore(&domain->iommu_lock, flags2);