@@ -3058,6 +3058,53 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle)
}
EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
+int iommu_set_dev_dma_opt_size(struct device *dev, size_t size)
+{
+ struct iommu_group *group = iommu_group_get(dev);
+ struct group_device *grp_dev;
+ struct device *_dev;
+ int ret, group_count;
+
+ if (!group)
+ return 0;
+
+ mutex_lock(&group->mutex);
+
+ /*
+ * If already set, then ignore. We may have been set via sysfs, so
+ * honour that.
+ */
+ if (group->max_opt_dma_size) {
+ ret = 0;
+ goto out;
+ }
+
+ group_count = iommu_group_device_count(group);
+ if (group_count != 1) {
+ dev_err_ratelimited(dev, "Cannot change DMA opt size: Group has more than one device group_count=%d\n",
+ group_count);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Since group has only one device */
+ grp_dev = list_first_entry(&group->devices, struct group_device, list);
+ _dev = grp_dev->dev;
+
+ if (_dev != dev) {
+ dev_err_ratelimited(dev, "Cannot set DMA max opt size - device has changed\n");
+ ret = -EBUSY;
+ goto out;
+ }
+
+ group->max_opt_dma_size = size;
+ ret = -EPROBE_DEFER;
+out:
+ mutex_unlock(&group->mutex);
+ iommu_group_put(group);
+ return ret;
+}
+
/*
* Changes the default domain of an iommu group that has *only* one device
*
@@ -428,6 +428,7 @@ extern void iommu_get_resv_regions(struct device *dev, struct list_head *list);
extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
extern void generic_iommu_put_resv_regions(struct device *dev,
struct list_head *list);
+extern int iommu_set_dev_dma_opt_size(struct device *dev, size_t size);
extern void iommu_set_default_passthrough(bool cmd_line);
extern void iommu_set_default_translated(bool cmd_line);
extern bool iommu_default_passthrough(void);
@@ -740,6 +741,12 @@ static inline int iommu_get_group_resv_regions(struct iommu_group *group,
return -ENODEV;
}
+static inline int iommu_set_dev_dma_opt_size(struct device *dev,
+ size_t size)
+{
+ return -ENODEV;
+}
+
static inline void iommu_set_default_passthrough(bool cmd_line)
{
}
Add a function which allows the max optimised IOMMU DMA size to be set. When set successfully, return -EPROBE_DEFER to inform the caller that the device driver needs to be reprobed to take effect. Signed-off-by: John Garry <john.garry@huawei.com> --- drivers/iommu/iommu.c | 47 +++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 7 +++++++ 2 files changed, 54 insertions(+) -- 2.26.2