iommu/vt-d: Keep track of per-iommu domain ids

Instead of searching in the domain array for already
allocated domain ids, keep track of them explicitly.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 013cbc2005797058e0388f8d59eeadbd6e176de5..bf92cd1805c245ad1e43a80b2ba6e16269769a43 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -378,6 +378,11 @@ struct dmar_domain {
        DECLARE_BITMAP(iommu_bmp, DMAR_UNITS_SUPPORTED);
                                        /* bitmap of iommus this domain uses*/
 
+       u16             iommu_did[DMAR_UNITS_SUPPORTED];
+                                       /* Domain ids per IOMMU. Use u16 since
+                                        * domain ids are 16 bit wide according
+                                        * to VT-d spec, section 9.3 */
+
        struct list_head devices;       /* all devices' list */
        struct iova_domain iovad;       /* iova's that belong to this domain */
 
@@ -1543,11 +1548,13 @@ static int iommu_init_domains(struct intel_iommu *iommu)
        }
 
        /*
-        * if Caching mode is set, then invalid translations are tagged
-        * with domainid 0. Hence we need to pre-allocate it.
+        * If Caching mode is set, then invalid translations are tagged
+        * with domain-id 0, hence we need to pre-allocate it. We also
+        * use domain-id 0 as a marker for non-allocated domain-id, so
+        * make sure it is not used for a real domain.
         */
-       if (cap_caching_mode(iommu->cap))
-               set_bit(0, iommu->domain_ids);
+       set_bit(0, iommu->domain_ids);
+
        return 0;
 }
 
@@ -1560,9 +1567,10 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
                for_each_set_bit(i, iommu->domain_ids, cap_ndoms(iommu->cap)) {
                        /*
                         * Domain id 0 is reserved for invalid translation
-                        * if hardware supports caching mode.
+                        * if hardware supports caching mode and used as
+                        * a non-allocated marker.
                         */
-                       if (cap_caching_mode(iommu->cap) && i == 0)
+                       if (i == 0)
                                continue;
 
                        domain = iommu->domains[i];
@@ -1624,6 +1632,7 @@ static int __iommu_attach_domain(struct dmar_domain *domain,
        if (num < ndomains) {
                set_bit(num, iommu->domain_ids);
                iommu->domains[num] = domain;
+               domain->iommu_did[iommu->seq_id] = num;
        } else {
                num = -ENOSPC;
        }
@@ -1650,12 +1659,10 @@ static int iommu_attach_vm_domain(struct dmar_domain *domain,
                                  struct intel_iommu *iommu)
 {
        int num;
-       unsigned long ndomains;
 
-       ndomains = cap_ndoms(iommu->cap);
-       for_each_set_bit(num, iommu->domain_ids, ndomains)
-               if (iommu->domains[num] == domain)
-                       return num;
+       num = domain->iommu_did[iommu->seq_id];
+       if (num)
+               return num;
 
        return __iommu_attach_domain(domain, iommu);
 }
@@ -1664,22 +1671,18 @@ static void iommu_detach_domain(struct dmar_domain *domain,
                                struct intel_iommu *iommu)
 {
        unsigned long flags;
-       int num, ndomains;
+       int num;
 
        spin_lock_irqsave(&iommu->lock, flags);
-       if (domain_type_is_vm_or_si(domain)) {
-               ndomains = cap_ndoms(iommu->cap);
-               for_each_set_bit(num, iommu->domain_ids, ndomains) {
-                       if (iommu->domains[num] == domain) {
-                               clear_bit(num, iommu->domain_ids);
-                               iommu->domains[num] = NULL;
-                               break;
-                       }
-               }
-       } else {
-               clear_bit(domain->id, iommu->domain_ids);
-               iommu->domains[domain->id] = NULL;
-       }
+
+       num = domain->iommu_did[iommu->seq_id];
+
+       if (num == 0)
+               return;
+
+       clear_bit(num, iommu->domain_ids);
+       iommu->domains[num]              = NULL;
+
        spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
@@ -1708,6 +1711,7 @@ static int domain_detach_iommu(struct dmar_domain *domain,
        if (test_and_clear_bit(iommu->seq_id, domain->iommu_bmp)) {
                count = --domain->iommu_count;
                domain_update_iommu_cap(domain);
+               domain->iommu_did[iommu->seq_id] = 0;
        }
        spin_unlock_irqrestore(&domain->iommu_lock, flags);