arch/arm/include/asm/dma-mapping.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef ASMARM_DMA_MAPPING_H
   3 #define ASMARM_DMA_MAPPING_H
   4
   5 #ifdef __KERNEL__
   6
   7 #include <linux/mm_types.h>
   8 #include <linux/scatterlist.h>
   9 #include <linux/dma-debug.h>
  10
  11 #include <asm/memory.h>
  12
  13 #include <xen/xen.h>
  14 #include <asm/xen/hypervisor.h>
  15
  16 extern const struct dma_map_ops arm_dma_ops;
  17 extern const struct dma_map_ops arm_coherent_dma_ops;
  18
  19 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
  20 {
  21         if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
  22                 return &arm_dma_ops;
  23         return NULL;
  24 }
  25
  26 #ifdef __arch_page_to_dma
  27 #error Please update to __arch_pfn_to_dma
  28 #endif
  29
  30 /*
  31  * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
  32  * functions used internally by the DMA-mapping API to provide DMA
  33  * addresses. They must not be used by drivers.
  34  */
  35 #ifndef __arch_pfn_to_dma
  36 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
  37 {
  38         if (dev)
  39                 pfn -= dev->dma_pfn_offset;
  40         return (dma_addr_t)__pfn_to_bus(pfn);
  41 }
  42
  43 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
  44 {
  45         unsigned long pfn = __bus_to_pfn(addr);
  46
  47         if (dev)
  48                 pfn += dev->dma_pfn_offset;
  49
  50         return pfn;
  51 }
  52
  53 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  54 {
  55         if (dev) {
  56                 unsigned long pfn = dma_to_pfn(dev, addr);
  57
  58                 return phys_to_virt(__pfn_to_phys(pfn));
  59         }
  60
  61         return (void *)__bus_to_virt((unsigned long)addr);
  62 }
  63
  64 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  65 {
  66         if (dev)
  67                 return pfn_to_dma(dev, virt_to_pfn(addr));
  68
  69         return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
  70 }
  71
  72 #else
  73 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
  74 {
  75         return __arch_pfn_to_dma(dev, pfn);
  76 }
  77
  78 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
  79 {
  80         return __arch_dma_to_pfn(dev, addr);
  81 }
  82
  83 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  84 {
  85         return __arch_dma_to_virt(dev, addr);
  86 }
  87
  88 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  89 {
  90         return __arch_virt_to_dma(dev, addr);
  91 }
  92 #endif
  93
  94 /**
  95  * arm_dma_alloc - allocate consistent memory for DMA
  96  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  97  * @size: required memory size
  98  * @handle: bus-specific DMA address
  99  * @attrs: optinal attributes that specific mapping properties
 100  *
 101  * Allocate some memory for a device for performing DMA.  This function
 102  * allocates pages, and will return the CPU-viewed address, and sets @handle
 103  * to be the device-viewed address.
 104  */
 105 extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 106                            gfp_t gfp, unsigned long attrs);
 107
 108 /**
 109  * arm_dma_free - free memory allocated by arm_dma_alloc
 110  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 111  * @size: size of memory originally requested in dma_alloc_coherent
 112  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 113  * @handle: device-view address returned from dma_alloc_coherent
 114  * @attrs: optinal attributes that specific mapping properties
 115  *
 116  * Free (and unmap) a DMA buffer previously allocated by
 117  * arm_dma_alloc().
 118  *
 119  * References to memory and mappings associated with cpu_addr/handle
 120  * during and after this call executing are illegal.
 121  */
 122 extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 123                          dma_addr_t handle, unsigned long attrs);
 124
 125 /**
 126  * arm_dma_mmap - map a coherent DMA allocation into user space
 127  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 128  * @vma: vm_area_struct describing requested user mapping
 129  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 130  * @handle: device-view address returned from dma_alloc_coherent
 131  * @size: size of memory originally requested in dma_alloc_coherent
 132  * @attrs: optinal attributes that specific mapping properties
 133  *
 134  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 135  * into user space.  The coherent DMA buffer must not be freed by the
 136  * driver until the user space mapping has been released.
 137  */
 138 extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 139                         void *cpu_addr, dma_addr_t dma_addr, size_t size,
 140                         unsigned long attrs);
 141
 142 /*
 143  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 144  * and utilize bounce buffers as needed to work around limited DMA windows.
 145  *
 146  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 147  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 148  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 149  *
 150  * The following are helper functions used by the dmabounce subystem
 151  *
 152  */
 153
 154 /**
 155  * dmabounce_register_dev
 156  *
 157  * @dev: valid struct device pointer
 158  * @small_buf_size: size of buffers to use with small buffer pool
 159  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 160  * @needs_bounce_fn: called to determine whether buffer needs bouncing
 161  *
 162  * This function should be called by low-level platform code to register
 163  * a device as requireing DMA buffer bouncing. The function will allocate
 164  * appropriate DMA pools for the device.
 165  */
 166 extern int dmabounce_register_dev(struct device *, unsigned long,
 167                 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
 168
 169 /**
 170  * dmabounce_unregister_dev
 171  *
 172  * @dev: valid struct device pointer
 173  *
 174  * This function should be called by low-level platform code when device
 175  * that was previously registered with dmabounce_register_dev is removed
 176  * from the system.
 177  *
 178  */
 179 extern void dmabounce_unregister_dev(struct device *);
 180
 181
 182
 183 /*
 184  * The scatter list versions of the above methods.
 185  */
 186 extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
 187                 enum dma_data_direction, unsigned long attrs);
 188 extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
 189                 enum dma_data_direction, unsigned long attrs);
 190 extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 191                 enum dma_data_direction);
 192 extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 193                 enum dma_data_direction);
 194 extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 195                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 196                 unsigned long attrs);
 197
 198 #endif /* __KERNEL__ */
 199 #endif