Allow iommu_change_dev_def_domain() to create a new default domain, keeping
the same as current.
Also remove comment about the function purpose, which will become stale.
Signed-off-by: John Garry <john.ga...@huawei.com>
---
drivers/iommu/iommu.c | 49 ++++++++++++++++++++++---------------------
include/linux/iommu.h | 1 +
2 files changed, 26 insertions(+), 24 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 0dd766030baf..10bb10c2a210 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2863,6 +2863,7 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle)
}
EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
+
/*
* Changes the default domain of an iommu group that has *only* one device
*
@@ -2873,10 +2874,6 @@ EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
*
* Returns 0 on success and error code on failure
*
- * Note:
- * 1. Presently, this function is called only when user requests to change the
- * group's default domain type through
/sys/kernel/iommu_groups/<grp_id>/type
- * Please take a closer look if intended to use for other purposes.
*/
static int iommu_change_dev_def_domain(struct iommu_group *group,
struct device *prev_dev, int type)
@@ -2929,28 +2926,32 @@ static int iommu_change_dev_def_domain(struct
iommu_group *group,
goto out;
}
- dev_def_dom = iommu_get_def_domain_type(dev);
- if (!type) {
+ if (type == __IOMMU_DOMAIN_SAME) {
+ type = prev_dom->type;
+ } else {
+ dev_def_dom = iommu_get_def_domain_type(dev);
+ if (!type) {
+ /*
+ * If the user hasn't requested any specific type of
domain and
+ * if the device supports both the domains, then
default to the
+ * domain the device was booted with
+ */
+ type = dev_def_dom ? : iommu_def_domain_type;
+ } else if (dev_def_dom && type != dev_def_dom) {
+ dev_err_ratelimited(prev_dev, "Device cannot be in %s
domain\n",
+ iommu_domain_type_str(type));
+ ret = -EINVAL;
+ goto out;
+ }
+
/*
- * If the user hasn't requested any specific type of domain and
- * if the device supports both the domains, then default to the
- * domain the device was booted with
+ * Switch to a new domain only if the requested domain type is
different
+ * from the existing default domain type
*/
- type = dev_def_dom ? : iommu_def_domain_type;
- } else if (dev_def_dom && type != dev_def_dom) {
- dev_err_ratelimited(prev_dev, "Device cannot be in %s domain\n",
- iommu_domain_type_str(type));
- ret = -EINVAL;
- goto out;
- }
-
- /*
- * Switch to a new domain only if the requested domain type is different
- * from the existing default domain type
- */
- if (prev_dom->type == type) {
- ret = 0;
- goto out;
+ if (prev_dom->type == type) {
+ ret = 0;
+ goto out;
+ }
}
/* We can bring up a flush queue without tearing down the domain */
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 9208eca4b0d1..b141cf71c7af 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -63,6 +63,7 @@ struct iommu_domain_geometry {
implementation */
#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */
#define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */
+#define __IOMMU_DOMAIN_SAME (1U << 4) /* Keep same type (internal) */
/*
* This are the possible domain-types
--
2.26.2
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