iommu/vt-d: Manage scalalble mode PASID tables

In scalable mode, pasid structure is a two level table with
a pasid directory table and a pasid table. Any pasid entry
can be identified by a pasid value in below way.

   1
   9                       6 5      0
    .-----------------------.-------.
    |              PASID    |       |
    '-----------------------'-------'    .-------------.
             |                    |      |             |
             |                    |      |             |
             |                    |      |             |
             |     .-----------.  |      .-------------.
             |     |           |  |----->| PASID Entry |
             |     |           |  |      '-------------'
             |     |           |  |Plus  |             |
             |     .-----------.  |      |             |
             |---->| DIR Entry |-------->|             |
             |     '-----------'         '-------------'
.---------.  |Plus |           |
| Context |  |     |           |
|  Entry  |------->|           |
'---------'        '-----------'

This changes the pasid table APIs to support scalable mode
PASID directory and PASID table. It also adds a helper to
get the PASID table entry according to the pasid value.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 14 insertions, 9 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2b9784a1887b..5552a1aaf5ea 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -425,21 +425,24 @@ static LIST_HEAD(device_domain_list);
 
 /*
  * Iterate over elements in device_domain_list and call the specified
- * callback @fn against each element. This helper should only be used
- * in the context where the device_domain_lock has already been holden.
+ * callback @fn against each element.
  */
 int for_each_device_domain(int (*fn)(struct device_domain_info *info,
 				     void *data), void *data)
 {
 	int ret = 0;
+	unsigned long flags;
 	struct device_domain_info *info;
 
-	assert_spin_locked(&device_domain_lock);
+	spin_lock_irqsave(&device_domain_lock, flags);
 	list_for_each_entry(info, &device_domain_list, global) {
 		ret = fn(info, data);
-		if (ret)
+		if (ret) {
+			spin_unlock_irqrestore(&device_domain_lock, flags);
 			return ret;
+		}
 	}
+	spin_unlock_irqrestore(&device_domain_lock, flags);
 
 	return 0;
 }
@@ -2481,16 +2484,18 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 	list_add(&info->global, &device_domain_list);
 	if (dev)
 		dev->archdata.iommu = info;
+	spin_unlock_irqrestore(&device_domain_lock, flags);
 
-	if (dev && dev_is_pci(dev) && info->pasid_supported) {
+	/* PASID table is mandatory for a PCI device in scalable mode. */
+	if (dev && dev_is_pci(dev) && sm_supported(iommu)) {
 		ret = intel_pasid_alloc_table(dev);
 		if (ret) {
-			pr_warn("No pasid table for %s, pasid disabled\n",
-				dev_name(dev));
-			info->pasid_supported = 0;
+			pr_err("PASID table allocation for %s failed\n",
+			       dev_name(dev));
+			dmar_remove_one_dev_info(domain, dev);
+			return NULL;
 		}
 	}
-	spin_unlock_irqrestore(&device_domain_lock, flags);
 
 	if (dev && domain_context_mapping(domain, dev)) {
 		pr_err("Domain context map for %s failed\n", dev_name(dev));