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-rw-r--r--include/linux/iommu.h27
1 files changed, 26 insertions, 1 deletions
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index a325532aeab5..6f53ad74fa0d 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -455,7 +455,7 @@ extern void iommu_set_default_translated(bool cmd_line);
extern bool iommu_default_passthrough(void);
extern struct iommu_resv_region *
iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot,
- enum iommu_resv_type type);
+ enum iommu_resv_type type, gfp_t gfp);
extern int iommu_get_group_resv_regions(struct iommu_group *group,
struct list_head *head);
@@ -605,6 +605,10 @@ struct iommu_group *fsl_mc_device_group(struct device *dev);
* @flags: IOMMU_FWSPEC_* flags
* @num_ids: number of associated device IDs
* @ids: IDs which this device may present to the IOMMU
+ *
+ * Note that the IDs (and any other information, really) stored in this structure should be
+ * considered private to the IOMMU device driver and are not to be used directly by IOMMU
+ * consumers.
*/
struct iommu_fwspec {
const struct iommu_ops *ops;
@@ -1099,4 +1103,25 @@ static inline void iommu_dma_compose_msi_msg(struct msi_desc *desc, struct msi_m
#endif /* CONFIG_IOMMU_DMA */
+/*
+ * Newer generations of Tegra SoCs require devices' stream IDs to be directly programmed into
+ * some registers. These are always paired with a Tegra SMMU or ARM SMMU, for which the contents
+ * of the struct iommu_fwspec are known. Use this helper to formalize access to these internals.
+ */
+#define TEGRA_STREAM_ID_BYPASS 0x7f
+
+static inline bool tegra_dev_iommu_get_stream_id(struct device *dev, u32 *stream_id)
+{
+#ifdef CONFIG_IOMMU_API
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+ if (fwspec && fwspec->num_ids == 1) {
+ *stream_id = fwspec->ids[0] & 0xffff;
+ return true;
+ }
+#endif
+
+ return false;
+}
+
#endif /* __LINUX_IOMMU_H */