LXR linux/include/linux/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 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 */
 128