dma-direct.h

  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 u64 zone_dma_limit;
 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};
 25
 26static inline dma_addr_t translate_phys_to_dma(struct device *dev,
 27		phys_addr_t paddr)
 28{
 29	const struct bus_dma_region *m;
 30
 31	for (m = dev->dma_range_map; m->size; m++) {
 32		u64 offset = paddr - m->cpu_start;
 33
 34		if (paddr >= m->cpu_start && offset < m->size)
 35			return m->dma_start + offset;
 36	}
 37
 38	/* make sure dma_capable fails when no translation is available */
 39	return DMA_MAPPING_ERROR;
 40}
 41
 42static inline phys_addr_t translate_dma_to_phys(struct device *dev,
 43		dma_addr_t dma_addr)
 44{
 45	const struct bus_dma_region *m;
 46
 47	for (m = dev->dma_range_map; m->size; m++) {
 48		u64 offset = dma_addr - m->dma_start;
 49
 50		if (dma_addr >= m->dma_start && offset < m->size)
 51			return m->cpu_start + offset;
 52	}
 53
 54	return (phys_addr_t)-1;
 55}
 56
 57static inline dma_addr_t dma_range_map_min(const struct bus_dma_region *map)
 58{
 59	dma_addr_t ret = (dma_addr_t)U64_MAX;
 60
 61	for (; map->size; map++)
 62		ret = min(ret, map->dma_start);
 63	return ret;
 64}
 65
 66static inline dma_addr_t dma_range_map_max(const struct bus_dma_region *map)
 67{
 68	dma_addr_t ret = 0;
 69
 70	for (; map->size; map++)
 71		ret = max(ret, map->dma_start + map->size - 1);
 72	return ret;
 73}
 74
 75#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
 76#include <asm/dma-direct.h>
 77#ifndef phys_to_dma_unencrypted
 78#define phys_to_dma_unencrypted		phys_to_dma
 79#endif
 80#else
 81static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 82{
 83	if (dev->dma_range_map)
 84		return translate_phys_to_dma(dev, paddr);
 85	return paddr;
 86}
 87
 88static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev,
 89						phys_addr_t paddr)
 90{
 91	return dma_addr_unencrypted(__phys_to_dma(dev, paddr));
 92}
 93/*
 94 * If memory encryption is supported, phys_to_dma will set the memory encryption
 95 * bit in the DMA address, and dma_to_phys will clear it.
 96 * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb
 97 * buffers.
 98 */
 99static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
100{
101	return dma_addr_encrypted(__phys_to_dma(dev, paddr));
102}
103
104static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
105{
106	phys_addr_t paddr;
107
108	dma_addr = dma_addr_canonical(dma_addr);
109	if (dev->dma_range_map)
110		paddr = translate_dma_to_phys(dev, dma_addr);
111	else
112		paddr = dma_addr;
113
114	return paddr;
115}
116#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
117
118#ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
119bool force_dma_unencrypted(struct device *dev);
120#else
121static inline bool force_dma_unencrypted(struct device *dev)
122{
123	return false;
124}
125#endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */
126
127static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
128		bool is_ram)
129{
130	dma_addr_t end = addr + size - 1;
131
132	if (addr == DMA_MAPPING_ERROR)
133		return false;
134	if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
135	    min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
136		return false;
137
138	return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit);
139}
140
141u64 dma_direct_get_required_mask(struct device *dev);
142void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
143		gfp_t gfp, unsigned long attrs);
144void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
145		dma_addr_t dma_addr, unsigned long attrs);
146struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
147		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
148void dma_direct_free_pages(struct device *dev, size_t size,
149		struct page *page, dma_addr_t dma_addr,
150		enum dma_data_direction dir);
151int dma_direct_supported(struct device *dev, u64 mask);
152
153#endif /* _LINUX_DMA_DIRECT_H */