iommu: iommu_get_group_resv_regions

Introduce iommu_get_group_resv_regions whose role consists in
enumerating all devices from the group and collecting their
reserved regions. The list is sorted and overlaps between
regions of the same type are handled by merging the regions.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit 6c65fb318e8bbf21e939e651028b955324f1d873)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 41c190695749dd604a9a3f32f757d17cf73b829d..640056ba46c2402d703f67d947adc14e4f9863e0 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -133,6 +133,104 @@ static ssize_t iommu_group_show_name(struct iommu_group *group, char *buf)
        return sprintf(buf, "%s\n", group->name);
 }
 
+/**
+ * iommu_insert_resv_region - Insert a new region in the
+ * list of reserved regions.
+ * @new: new region to insert
+ * @regions: list of regions
+ *
+ * The new element is sorted by address with respect to the other
+ * regions of the same type. In case it overlaps with another
+ * region of the same type, regions are merged. In case it
+ * overlaps with another region of different type, regions are
+ * not merged.
+ */
+static int iommu_insert_resv_region(struct iommu_resv_region *new,
+                                   struct list_head *regions)
+{
+       struct iommu_resv_region *region;
+       phys_addr_t start = new->start;
+       phys_addr_t end = new->start + new->length - 1;
+       struct list_head *pos = regions->next;
+
+       while (pos != regions) {
+               struct iommu_resv_region *entry =
+                       list_entry(pos, struct iommu_resv_region, list);
+               phys_addr_t a = entry->start;
+               phys_addr_t b = entry->start + entry->length - 1;
+               int type = entry->type;
+
+               if (end < a) {
+                       goto insert;
+               } else if (start > b) {
+                       pos = pos->next;
+               } else if ((start >= a) && (end <= b)) {
+                       if (new->type == type)
+                               goto done;
+                       else
+                               pos = pos->next;
+               } else {
+                       if (new->type == type) {
+                               phys_addr_t new_start = min(a, start);
+                               phys_addr_t new_end = max(b, end);
+
+                               list_del(&entry->list);
+                               entry->start = new_start;
+                               entry->length = new_end - new_start + 1;
+                               iommu_insert_resv_region(entry, regions);
+                       } else {
+                               pos = pos->next;
+                       }
+               }
+       }
+insert:
+       region = iommu_alloc_resv_region(new->start, new->length,
+                                        new->prot, new->type);
+       if (!region)
+               return -ENOMEM;
+
+       list_add_tail(&region->list, pos);
+done:
+       return 0;
+}
+
+static int
+iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
+                                struct list_head *group_resv_regions)
+{
+       struct iommu_resv_region *entry;
+       int ret;
+
+       list_for_each_entry(entry, dev_resv_regions, list) {
+               ret = iommu_insert_resv_region(entry, group_resv_regions);
+               if (ret)
+                       break;
+       }
+       return ret;
+}
+
+int iommu_get_group_resv_regions(struct iommu_group *group,
+                                struct list_head *head)
+{
+       struct iommu_device *device;
+       int ret = 0;
+
+       mutex_lock(&group->mutex);
+       list_for_each_entry(device, &group->devices, list) {
+               struct list_head dev_resv_regions;
+
+               INIT_LIST_HEAD(&dev_resv_regions);
+               iommu_get_resv_regions(device->dev, &dev_resv_regions);
+               ret = iommu_insert_device_resv_regions(&dev_resv_regions, head);
+               iommu_put_resv_regions(device->dev, &dev_resv_regions);
+               if (ret)
+                       break;
+       }
+       mutex_unlock(&group->mutex);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_get_group_resv_regions);
+
 static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL);
 
 static void iommu_group_release(struct kobject *kobj)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index f6bb55d3e6063fe6c1e2c97bff499747a27cdf98..bec3730dc00937d11677a16f84cc0f396f0655ff 100644 (file)
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -246,6 +246,8 @@ extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
 extern int iommu_request_dm_for_dev(struct device *dev);
 extern struct iommu_resv_region *
 iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot, int type);
+extern int iommu_get_group_resv_regions(struct iommu_group *group,
+                                       struct list_head *head);
 
 extern int iommu_attach_group(struct iommu_domain *domain,
                              struct iommu_group *group);
@@ -463,6 +465,12 @@ static inline void iommu_put_resv_regions(struct device *dev,
 {
 }
 
+static inline int iommu_get_group_resv_regions(struct iommu_group *group,
+                                              struct list_head *head)
+{
+       return -ENODEV;
+}
+
 static inline int iommu_request_dm_for_dev(struct device *dev)
 {
        return -ENODEV;