direct.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright (C) 2018 Christoph Hellwig.
  4 *
  5 * DMA operations that map physical memory directly without using an IOMMU.
  6 */
  7#ifndef _KERNEL_DMA_DIRECT_H
  8#define _KERNEL_DMA_DIRECT_H
  9
 10#include <linux/dma-direct.h>
 11#include <linux/memremap.h>
 12
 13int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt,
 14		void *cpu_addr, dma_addr_t dma_addr, size_t size,
 15		unsigned long attrs);
 16bool dma_direct_can_mmap(struct device *dev);
 17int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
 18		void *cpu_addr, dma_addr_t dma_addr, size_t size,
 19		unsigned long attrs);
 20bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr);
 21int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
 22		enum dma_data_direction dir, unsigned long attrs);
 23bool dma_direct_all_ram_mapped(struct device *dev);
 24size_t dma_direct_max_mapping_size(struct device *dev);
 25
 26#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
 27    defined(CONFIG_SWIOTLB)
 28void dma_direct_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
 29		int nents, enum dma_data_direction dir);
 30#else
 31static inline void dma_direct_sync_sg_for_device(struct device *dev,
 32		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
 33{
 34}
 35#endif
 36
 37#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
 38    defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
 39    defined(CONFIG_SWIOTLB)
 40void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
 41		int nents, enum dma_data_direction dir, unsigned long attrs);
 42void dma_direct_sync_sg_for_cpu(struct device *dev,
 43		struct scatterlist *sgl, int nents, enum dma_data_direction dir);
 44#else
 45static inline void dma_direct_unmap_sg(struct device *dev,
 46		struct scatterlist *sgl, int nents, enum dma_data_direction dir,
 47		unsigned long attrs)
 48{
 49}
 50static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
 51		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
 52{
 53}
 54#endif
 55
 56static inline void dma_direct_sync_single_for_device(struct device *dev,
 57		dma_addr_t addr, size_t size, enum dma_data_direction dir)
 58{
 59	phys_addr_t paddr = dma_to_phys(dev, addr);
 60
 61	swiotlb_sync_single_for_device(dev, paddr, size, dir);
 62
 63	if (!dev_is_dma_coherent(dev))
 64		arch_sync_dma_for_device(paddr, size, dir);
 65}
 66
 67static inline void dma_direct_sync_single_for_cpu(struct device *dev,
 68		dma_addr_t addr, size_t size, enum dma_data_direction dir)
 69{
 70	phys_addr_t paddr = dma_to_phys(dev, addr);
 71
 72	if (!dev_is_dma_coherent(dev)) {
 73		arch_sync_dma_for_cpu(paddr, size, dir);
 74		arch_sync_dma_for_cpu_all();
 75	}
 76
 77	swiotlb_sync_single_for_cpu(dev, paddr, size, dir);
 78
 79	if (dir == DMA_FROM_DEVICE)
 80		arch_dma_mark_clean(paddr, size);
 81}
 82
 83static inline dma_addr_t dma_direct_map_phys(struct device *dev,
 84		phys_addr_t phys, size_t size, enum dma_data_direction dir,
 85		unsigned long attrs)
 86{
 87	dma_addr_t dma_addr;
 88
 89	if (is_swiotlb_force_bounce(dev)) {
 90		if (attrs & DMA_ATTR_MMIO)
 91			return DMA_MAPPING_ERROR;
 92
 93		return swiotlb_map(dev, phys, size, dir, attrs);
 94	}
 95
 96	if (attrs & DMA_ATTR_MMIO) {
 97		dma_addr = phys;
 98		if (unlikely(!dma_capable(dev, dma_addr, size, false)))
 99			goto err_overflow;
100	} else {
101		dma_addr = phys_to_dma(dev, phys);
102		if (unlikely(!dma_capable(dev, dma_addr, size, true)) ||
103		    dma_kmalloc_needs_bounce(dev, size, dir)) {
104			if (is_swiotlb_active(dev))
105				return swiotlb_map(dev, phys, size, dir, attrs);
106
107			goto err_overflow;
108		}
109	}
110
111	if (!dev_is_dma_coherent(dev) &&
112	    !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO)))
113		arch_sync_dma_for_device(phys, size, dir);
114	return dma_addr;
115
116err_overflow:
117	dev_WARN_ONCE(
118		dev, 1,
119		"DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
120		&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
121	return DMA_MAPPING_ERROR;
122}
123
124static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
125		size_t size, enum dma_data_direction dir, unsigned long attrs)
126{
127	phys_addr_t phys;
128
129	if (attrs & DMA_ATTR_MMIO)
130		/* nothing to do: uncached and no swiotlb */
131		return;
132
133	phys = dma_to_phys(dev, addr);
134	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
135		dma_direct_sync_single_for_cpu(dev, addr, size, dir);
136
137	swiotlb_tbl_unmap_single(dev, phys, size, dir,
138					 attrs | DMA_ATTR_SKIP_CPU_SYNC);
139}
140#endif /* _KERNEL_DMA_DIRECT_H */