v4.19.13 snapshot.
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
new file mode 100644
index 0000000..965be92
--- /dev/null
+++ b/include/linux/swiotlb.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_SWIOTLB_H
+#define __LINUX_SWIOTLB_H
+
+#include <linux/dma-direction.h>
+#include <linux/init.h>
+#include <linux/types.h>
+
+struct device;
+struct page;
+struct scatterlist;
+
+enum swiotlb_force {
+ SWIOTLB_NORMAL, /* Default - depending on HW DMA mask etc. */
+ SWIOTLB_FORCE, /* swiotlb=force */
+ SWIOTLB_NO_FORCE, /* swiotlb=noforce */
+};
+
+extern enum swiotlb_force swiotlb_force;
+
+/*
+ * Maximum allowable number of contiguous slabs to map,
+ * must be a power of 2. What is the appropriate value ?
+ * The complexity of {map,unmap}_single is linearly dependent on this value.
+ */
+#define IO_TLB_SEGSIZE 128
+
+/*
+ * log of the size of each IO TLB slab. The number of slabs is command line
+ * controllable.
+ */
+#define IO_TLB_SHIFT 11
+
+extern void swiotlb_init(int verbose);
+int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
+extern unsigned long swiotlb_nr_tbl(void);
+unsigned long swiotlb_size_or_default(void);
+extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);
+extern void __init swiotlb_update_mem_attributes(void);
+
+/*
+ * Enumeration for sync targets
+ */
+enum dma_sync_target {
+ SYNC_FOR_CPU = 0,
+ SYNC_FOR_DEVICE = 1,
+};
+
+/* define the last possible byte of physical address space as a mapping error */
+#define SWIOTLB_MAP_ERROR (~(phys_addr_t)0x0)
+
+extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
+ dma_addr_t tbl_dma_addr,
+ phys_addr_t phys, size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs);
+
+extern void swiotlb_tbl_unmap_single(struct device *hwdev,
+ phys_addr_t tlb_addr,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs);
+
+extern void swiotlb_tbl_sync_single(struct device *hwdev,
+ phys_addr_t tlb_addr,
+ size_t size, enum dma_data_direction dir,
+ enum dma_sync_target target);
+
+/* Accessory functions. */
+
+void *swiotlb_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle,
+ gfp_t flags, unsigned long attrs);
+void swiotlb_free(struct device *dev, size_t size, void *vaddr,
+ dma_addr_t dma_addr, unsigned long attrs);
+
+extern dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs);
+extern void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs);
+
+extern int
+swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir,
+ unsigned long attrs);
+
+extern void
+swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
+ int nelems, enum dma_data_direction dir,
+ unsigned long attrs);
+
+extern void
+swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir);
+
+extern void
+swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
+ int nelems, enum dma_data_direction dir);
+
+extern void
+swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir);
+
+extern void
+swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
+ int nelems, enum dma_data_direction dir);
+
+extern int
+swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr);
+
+extern int
+swiotlb_dma_supported(struct device *hwdev, u64 mask);
+
+#ifdef CONFIG_SWIOTLB
+extern void __init swiotlb_exit(void);
+unsigned int swiotlb_max_segment(void);
+#else
+static inline void swiotlb_exit(void) { }
+static inline unsigned int swiotlb_max_segment(void) { return 0; }
+#endif
+
+extern void swiotlb_print_info(void);
+extern int is_swiotlb_buffer(phys_addr_t paddr);
+extern void swiotlb_set_max_segment(unsigned int);
+
+extern const struct dma_map_ops swiotlb_dma_ops;
+
+#endif /* __LINUX_SWIOTLB_H */