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         return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_direct_ops;
  22 }
  23
  24 #ifdef __arch_page_to_dma
  25 #error Please update to __arch_pfn_to_dma
  26 #endif
  27
  28 /*
  29  * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
  30  * functions used internally by the DMA-mapping API to provide DMA
  31  * addresses. They must not be used by drivers.
  32  */
  33 #ifndef __arch_pfn_to_dma
  34 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
  35 {
  36         if (dev)
  37                 pfn -= dev->dma_pfn_offset;
  38         return (dma_addr_t)__pfn_to_bus(pfn);
  39 }
  40
  41 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
  42 {
  43         unsigned long pfn = __bus_to_pfn(addr);
  44
  45         if (dev)
  46                 pfn += dev->dma_pfn_offset;
  47
  48         return pfn;
  49 }
  50
  51 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  52 {
  53         if (dev) {
  54                 unsigned long pfn = dma_to_pfn(dev, addr);
  55
  56                 return phys_to_virt(__pfn_to_phys(pfn));
  57         }
  58
  59         return (void *)__bus_to_virt((unsigned long)addr);
  60 }
  61
  62 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  63 {
  64         if (dev)
  65                 return pfn_to_dma(dev, virt_to_pfn(addr));
  66
  67         return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
  68 }
  69
  70 #else
  71 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
  72 {
  73         return __arch_pfn_to_dma(dev, pfn);
  74 }
  75
  76 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
  77 {
  78         return __arch_dma_to_pfn(dev, addr);
  79 }
  80
  81 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  82 {
  83         return __arch_dma_to_virt(dev, addr);
  84 }
  85
  86 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  87 {
  88         return __arch_virt_to_dma(dev, addr);
  89 }
  90 #endif
  91
  92 /* The ARM override for dma_max_pfn() */
  93 static inline unsigned long dma_max_pfn(struct device *dev)
  94 {
  95         return dma_to_pfn(dev, *dev->dma_mask);
  96 }
  97 #define dma_max_pfn(dev) dma_max_pfn(dev)
  98
  99 #define arch_setup_dma_ops arch_setup_dma_ops
 100 extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 101                                const struct iommu_ops *iommu, bool coherent);
 102
 103 #define arch_teardown_dma_ops arch_teardown_dma_ops
 104 extern void arch_teardown_dma_ops(struct device *dev);
 105
 106 /* do not use this function in a driver */
 107 static inline bool is_device_dma_coherent(struct device *dev)
 108 {
 109         return dev->archdata.dma_coherent;
 110 }
 111
 112 /**
 113  * arm_dma_alloc - allocate consistent memory for DMA
 114  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 115  * @size: required memory size
 116  * @handle: bus-specific DMA address
 117  * @attrs: optinal attributes that specific mapping properties
 118  *
 119  * Allocate some memory for a device for performing DMA.  This function
 120  * allocates pages, and will return the CPU-viewed address, and sets @handle
 121  * to be the device-viewed address.
 122  */
 123 extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 124                            gfp_t gfp, unsigned long attrs);
 125
 126 /**
 127  * arm_dma_free - free memory allocated by arm_dma_alloc
 128  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 129  * @size: size of memory originally requested in dma_alloc_coherent
 130  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 131  * @handle: device-view address returned from dma_alloc_coherent
 132  * @attrs: optinal attributes that specific mapping properties
 133  *
 134  * Free (and unmap) a DMA buffer previously allocated by
 135  * arm_dma_alloc().
 136  *
 137  * References to memory and mappings associated with cpu_addr/handle
 138  * during and after this call executing are illegal.
 139  */
 140 extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 141                          dma_addr_t handle, unsigned long attrs);
 142
 143 /**
 144  * arm_dma_mmap - map a coherent DMA allocation into user space
 145  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 146  * @vma: vm_area_struct describing requested user mapping
 147  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 148  * @handle: device-view address returned from dma_alloc_coherent
 149  * @size: size of memory originally requested in dma_alloc_coherent
 150  * @attrs: optinal attributes that specific mapping properties
 151  *
 152  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 153  * into user space.  The coherent DMA buffer must not be freed by the
 154  * driver until the user space mapping has been released.
 155  */
 156 extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 157                         void *cpu_addr, dma_addr_t dma_addr, size_t size,
 158                         unsigned long attrs);
 159
 160 /*
 161  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 162  * and utilize bounce buffers as needed to work around limited DMA windows.
 163  *
 164  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 165  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 166  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 167  *
 168  * The following are helper functions used by the dmabounce subystem
 169  *
 170  */
 171
 172 /**
 173  * dmabounce_register_dev
 174  *
 175  * @dev: valid struct device pointer
 176  * @small_buf_size: size of buffers to use with small buffer pool
 177  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 178  * @needs_bounce_fn: called to determine whether buffer needs bouncing
 179  *
 180  * This function should be called by low-level platform code to register
 181  * a device as requireing DMA buffer bouncing. The function will allocate
 182  * appropriate DMA pools for the device.
 183  */
 184 extern int dmabounce_register_dev(struct device *, unsigned long,
 185                 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
 186
 187 /**
 188  * dmabounce_unregister_dev
 189  *
 190  * @dev: valid struct device pointer
 191  *
 192  * This function should be called by low-level platform code when device
 193  * that was previously registered with dmabounce_register_dev is removed
 194  * from the system.
 195  *
 196  */
 197 extern void dmabounce_unregister_dev(struct device *);
 198
 199
 200
 201 /*
 202  * The scatter list versions of the above methods.
 203  */
 204 extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
 205                 enum dma_data_direction, unsigned long attrs);
 206 extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
 207                 enum dma_data_direction, unsigned long attrs);
 208 extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 209                 enum dma_data_direction);
 210 extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 211                 enum dma_data_direction);
 212 extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 213                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 214                 unsigned long attrs);
 215
 216 #endif /* __KERNEL__ */
 217 #endif