Line data    Source code

       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             : 
      15             : extern unsigned int zone_dma_bits;
      16             : 
      17             : /*
      18             :  * Record the mapping of CPU physical to DMA addresses for a given region.
      19             :  */
      20             : struct bus_dma_region {
      21             :         phys_addr_t     cpu_start;
      22             :         dma_addr_t      dma_start;
      23             :         u64             size;
      24             :         u64             offset;
      25             : };
      26             : 
      27           0 : static inline dma_addr_t translate_phys_to_dma(struct device *dev,
      28             :                 phys_addr_t paddr)
      29             : {
      30           0 :         const struct bus_dma_region *m;
      31             : 
      32           0 :         for (m = dev->dma_range_map; m->size; m++)
      33           0 :                 if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size)
      34           0 :                         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             : 
      40           0 : static inline phys_addr_t translate_dma_to_phys(struct device *dev,
      41             :                 dma_addr_t dma_addr)
      42             : {
      43           0 :         const struct bus_dma_region *m;
      44             : 
      45           0 :         for (m = dev->dma_range_map; m->size; m++)
      46           0 :                 if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size)
      47           0 :                         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
      58           0 : static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev,
      59             :                 phys_addr_t paddr)
      60             : {
      61           0 :         if (dev->dma_range_map)
      62           0 :                 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             :  */
      72           0 : static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
      73             : {
      74           0 :         return __sme_set(phys_to_dma_unencrypted(dev, paddr));
      75             : }
      76             : 
      77           0 : static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
      78             : {
      79           0 :         phys_addr_t paddr;
      80             : 
      81           0 :         if (dev->dma_range_map)
      82           0 :                 paddr = translate_dma_to_phys(dev, dma_addr);
      83             :         else
      84             :                 paddr = dma_addr;
      85             : 
      86           0 :         return __sme_clr(paddr);
      87             : }
      88             : #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
      89             : 
      90             : #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
      91             : bool force_dma_unencrypted(struct device *dev);
      92             : #else
      93           0 : static inline bool force_dma_unencrypted(struct device *dev)
      94             : {
      95           0 :         return false;
      96             : }
      97             : #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */
      98             : 
      99           0 : static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
     100             :                 bool is_ram)
     101             : {
     102           0 :         dma_addr_t end = addr + size - 1;
     103             : 
     104           0 :         if (addr == DMA_MAPPING_ERROR)
     105             :                 return false;
     106           0 :         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           0 :         return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit);
     111             : }
     112             : 
     113             : u64 dma_direct_get_required_mask(struct device *dev);
     114             : void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
     115             :                 gfp_t gfp, unsigned long attrs);
     116             : void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
     117             :                 dma_addr_t dma_addr, unsigned long attrs);
     118             : struct 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);
     120             : void 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);
     123             : int dma_direct_supported(struct device *dev, u64 mask);
     124             : dma_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 */