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 are checked.
Signed-off-by: Eric Auger <eric.au...@redhat.com>
---
v3 -> v4:
- take the iommu_group lock in iommu_get_group_resv_regions
- the list now is sorted and overlaps are checked
NOTE:
- we do not move list elements from device to group list since
the iommu_put_resv_regions() could not be called.
- at the moment I did not introduce any iommu_put_group_resv_regions
since it simply consists in voiding/freeing the list
---
drivers/iommu/iommu.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/iommu.h | 8 ++++++
2 files changed, 86 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index ae3d97b..1565df4 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -133,6 +133,84 @@ static ssize_t iommu_group_show_name(struct iommu_group
*group, char *buf)
return sprintf(buf, "%s\n", group->name);
}
+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;
+
+ if (end < a) {
+ goto insert;
+ } else if (start > b) {
+ pos = pos->next;
+ } else if ((start >= a) && (end <= b)) {
+ goto done;
+ } else {
+ 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);
+ }
+ }
+insert:
+ region = iommu_alloc_resv_region(new->start, new->length,
+ new->prot, new->type);
+ if (!region)
+ return -ENOMEM;
+
+ list_add_tail(®ion->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 66b0c1c..f7c0606 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -246,6 +246,8 @@ extern void iommu_set_fault_handler(struct iommu_domain
*domain,
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);
@@ -459,6 +461,12 @@ 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;
--
1.9.1
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