iommu: Simplify and fix ida handling

Ida handling can be much simplified by using the ida_simple_.. functions.

This change also fixes the bug that previously checking for errors
returned by ida_get_new() was incomplete.
ida_get_new() can return errors other than EAGAIN, e.g. ENOSPC.
This case wasn't handled.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index debce45b5b8c676b036b4bdfea419210a8e0e536..4d3c4a82af03f574423abdb383a44f716f68d4ac 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -35,7 +35,6 @@
 
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
-static DEFINE_MUTEX(iommu_group_mutex);
 
 struct iommu_callback_data {
        const struct iommu_ops *ops;
@@ -144,9 +143,7 @@ static void iommu_group_release(struct kobject *kobj)
        if (group->iommu_data_release)
                group->iommu_data_release(group->iommu_data);
 
-       mutex_lock(&iommu_group_mutex);
-       ida_remove(&iommu_group_ida, group->id);
-       mutex_unlock(&iommu_group_mutex);
+       ida_simple_remove(&iommu_group_ida, group->id);
 
        if (group->default_domain)
                iommu_domain_free(group->default_domain);
@@ -186,26 +183,17 @@ struct iommu_group *iommu_group_alloc(void)
        INIT_LIST_HEAD(&group->devices);
        BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
 
-       mutex_lock(&iommu_group_mutex);
-
-again:
-       if (unlikely(0 == ida_pre_get(&iommu_group_ida, GFP_KERNEL))) {
+       ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL);
+       if (ret < 0) {
                kfree(group);
-               mutex_unlock(&iommu_group_mutex);
-               return ERR_PTR(-ENOMEM);
+               return ERR_PTR(ret);
        }
-
-       if (-EAGAIN == ida_get_new(&iommu_group_ida, &group->id))
-               goto again;
-
-       mutex_unlock(&iommu_group_mutex);
+       group->id = ret;
 
        ret = kobject_init_and_add(&group->kobj, &iommu_group_ktype,
                                   NULL, "%d", group->id);
        if (ret) {
-               mutex_lock(&iommu_group_mutex);
-               ida_remove(&iommu_group_ida, group->id);
-               mutex_unlock(&iommu_group_mutex);
+               ida_simple_remove(&iommu_group_ida, group->id);
                kfree(group);
                return ERR_PTR(ret);
        }