Reserved Memory Regions(RMR) associated with an IOMMU can be
described through ACPI IORT tables in systems with devices
that require a unity mapping or bypass for those
regions.
Introduce a generic interface so that IOMMU drivers can retrieve
and set up necessary mappings. Also introduce a union to struct
iommu_resv_region to hold any firmware specific data(eg:RMR
specific info).
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
drivers/iommu/dma-iommu.c | 29 +++++++++++++++++++++++++++++
include/linux/dma-iommu.h | 13 +++++++++++++
include/linux/iommu.h | 10 ++++++++++
3 files changed, 52 insertions(+)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 7bcdd1205535..229ec65d98be 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -174,6 +174,35 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
}
EXPORT_SYMBOL(iommu_put_dma_cookie);
+/**
+ *
+ * iommu_dma_get_rmrs - Retrieve Reserved Memory Regions(RMRs) associated
+ * with a given IOMMU
+ * @iommu_fwnode: fwnode associated with IOMMU
+ * @list: RMR list to be populated
+ *
+ */
+int iommu_dma_get_rmrs(struct fwnode_handle *iommu_fwnode,
+ struct list_head *list)
+{
+ return -EINVAL;
+}
+EXPORT_SYMBOL(iommu_dma_get_rmrs);
+
+/**
+ *
+ * iommu_dma_put_rmrs - Release Reserved Memory Regions(RMRs) associated
+ * with a given IOMMU
+ * @iommu_fwnode: fwnode associated with IOMMU
+ * @list: RMR list
+ *
+ */
+void iommu_dma_put_rmrs(struct fwnode_handle *iommu_fwnode,
+ struct list_head *list)
+{
+}
+EXPORT_SYMBOL(iommu_dma_put_rmrs);
+
/**
* iommu_dma_get_resv_regions - Reserved region driver helper
* @dev: Device from iommu_get_resv_regions()
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 6e75a2d689b4..a83e6c09444c 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -42,12 +42,16 @@ void iommu_dma_free_cpu_cached_iovas(unsigned int cpu,
extern bool iommu_dma_forcedac;
+int iommu_dma_get_rmrs(struct fwnode_handle *iommu, struct list_head *list);
+void iommu_dma_put_rmrs(struct fwnode_handle *iommu, struct list_head *list);
+
#else /* CONFIG_IOMMU_DMA */
struct iommu_domain;
struct msi_desc;
struct msi_msg;
struct device;
+struct fwnode_handle;
static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
u64 size)
@@ -83,5 +87,14 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he
{
}
+int iommu_dma_get_rmrs(struct fwnode_handle *iommu, struct list_head *list)
+{
+ return -ENODEV;
+}
+
+void iommu_dma_put_rmrs(struct fwnode_handle *iommu, struct list_head *list)
+{
+}
+
#endif /* CONFIG_IOMMU_DMA */
#endif /* __DMA_IOMMU_H */
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 32d448050bf7..856a1736c744 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -114,6 +114,12 @@ enum iommu_resv_type {
IOMMU_RESV_SW_MSI,
};
+struct iommu_iort_rmr_data {
+#define IOMMU_RMR_REMAP_PERMITTED (1 << 0)
+ u32 flags;
+ u32 sid; /* Stream Id associated with RMR entry */
+};
+
/**
* struct iommu_resv_region - descriptor for a reserved memory region
* @list: Linked list pointers
@@ -121,6 +127,7 @@ enum iommu_resv_type {
* @length: Length of the region in bytes
* @prot: IOMMU Protection flags (READ/WRITE/...)
* @type: Type of the reserved region
+ * @rmr: ACPI IORT RMR specific data
*/
struct iommu_resv_region {
struct list_head list;
@@ -128,6 +135,9 @@ struct iommu_resv_region {
size_t length;
int prot;
enum iommu_resv_type type;
+ union {
+ struct iommu_iort_rmr_data rmr;
+ } fw_data;
};
/**
--
2.17.1
