1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Internals of the DMA direct mapping implementation.  Only for use by the
  4 * DMA mapping code and IOMMU drivers.
  5 */
  6#ifndef _LINUX_DMA_DIRECT_H
  7#define _LINUX_DMA_DIRECT_H 1
  8
  9#include <linux/dma-mapping.h>
 10#include <linux/dma-map-ops.h>
 11#include <linux/memblock.h> /* for min_low_pfn */
 12#include <linux/mem_encrypt.h>
 13#include <linux/swiotlb.h>
 14
 15extern unsigned int zone_dma_bits;
 16
 17/*
 18 * Record the mapping of CPU physical to DMA addresses for a given region.
 19 */
 20struct bus_dma_region {
 21	phys_addr_t	cpu_start;
 22	dma_addr_t	dma_start;
 23	u64		size;
 24	u64		offset;
 25};
 26
 27static inline dma_addr_t translate_phys_to_dma(struct device *dev,
 28		phys_addr_t paddr)
 29{
 30	const struct bus_dma_region *m;
 31
 32	for (m = dev->dma_range_map; m->size; m++)
 33		if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size)
 34			return (dma_addr_t)paddr - m->offset;
 35
 36	/* make sure dma_capable fails when no translation is available */
 37	return DMA_MAPPING_ERROR;
 38}
 39
 40static inline phys_addr_t translate_dma_to_phys(struct device *dev,
 41		dma_addr_t dma_addr)
 42{
 43	const struct bus_dma_region *m;
 44
 45	for (m = dev->dma_range_map; m->size; m++)
 46		if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size)
 47			return (phys_addr_t)dma_addr + m->offset;
 48
 49	return (phys_addr_t)-1;
 50}
 51
 52#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
 53#include <asm/dma-direct.h>
 54#ifndef phys_to_dma_unencrypted
 55#define phys_to_dma_unencrypted		phys_to_dma
 56#endif
 57#else
 58static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev,
 59		phys_addr_t paddr)
 60{
 61	if (dev->dma_range_map)
 62		return translate_phys_to_dma(dev, paddr);
 63	return paddr;
 64}
 65
 66/*
 67 * If memory encryption is supported, phys_to_dma will set the memory encryption
 68 * bit in the DMA address, and dma_to_phys will clear it.
 69 * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb
 70 * buffers.
 71 */
 72static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 73{
 74	return __sme_set(phys_to_dma_unencrypted(dev, paddr));
 75}
 76
 77static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
 78{
 79	phys_addr_t paddr;
 80
 81	if (dev->dma_range_map)
 82		paddr = translate_dma_to_phys(dev, dma_addr);
 83	else
 84		paddr = dma_addr;
 85
 86	return __sme_clr(paddr);
 87}
 88#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
 89
 90#ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
 91bool force_dma_unencrypted(struct device *dev);
 92#else
 93static inline bool force_dma_unencrypted(struct device *dev)
 94{
 95	return false;
 96}
 97#endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */
 98
 99static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
100		bool is_ram)
101{
102	dma_addr_t end = addr + size - 1;
103
104	if (addr == DMA_MAPPING_ERROR)
105		return false;
106	if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
107	    min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
108		return false;
109
110	return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit);
111}
112
113u64 dma_direct_get_required_mask(struct device *dev);
114void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
115		gfp_t gfp, unsigned long attrs);
116void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
117		dma_addr_t dma_addr, unsigned long attrs);
118struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
119		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
120void dma_direct_free_pages(struct device *dev, size_t size,
121		struct page *page, dma_addr_t dma_addr,
122		enum dma_data_direction dir);
123int dma_direct_supported(struct device *dev, u64 mask);
124dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,
125		size_t size, enum dma_data_direction dir, unsigned long attrs);
126
127#endif /* _LINUX_DMA_DIRECT_H */