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
  10 #include <xen/xen.h>
  11 #include <asm/xen/hypervisor.h>
  12
  13 extern const struct dma_map_ops arm_dma_ops;
  14 extern const struct dma_map_ops arm_coherent_dma_ops;
  15
  16 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
  17 {
  18         if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
  19                 return &arm_dma_ops;
  20         return NULL;
  21 }
  22
  23 /**
  24  * arm_dma_alloc - allocate consistent memory for DMA
  25  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  26  * @size: required memory size
  27  * @handle: bus-specific DMA address
  28  * @attrs: optinal attributes that specific mapping properties
  29  *
  30  * Allocate some memory for a device for performing DMA.  This function
  31  * allocates pages, and will return the CPU-viewed address, and sets @handle
  32  * to be the device-viewed address.
  33  */
  34 extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
  35                            gfp_t gfp, unsigned long attrs);
  36
  37 /**
  38  * arm_dma_free - free memory allocated by arm_dma_alloc
  39  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  40  * @size: size of memory originally requested in dma_alloc_coherent
  41  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
  42  * @handle: device-view address returned from dma_alloc_coherent
  43  * @attrs: optinal attributes that specific mapping properties
  44  *
  45  * Free (and unmap) a DMA buffer previously allocated by
  46  * arm_dma_alloc().
  47  *
  48  * References to memory and mappings associated with cpu_addr/handle
  49  * during and after this call executing are illegal.
  50  */
  51 extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
  52                          dma_addr_t handle, unsigned long attrs);
  53
  54 /**
  55  * arm_dma_mmap - map a coherent DMA allocation into user space
  56  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  57  * @vma: vm_area_struct describing requested user mapping
  58  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
  59  * @handle: device-view address returned from dma_alloc_coherent
  60  * @size: size of memory originally requested in dma_alloc_coherent
  61  * @attrs: optinal attributes that specific mapping properties
  62  *
  63  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
  64  * into user space.  The coherent DMA buffer must not be freed by the
  65  * driver until the user space mapping has been released.
  66  */
  67 extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
  68                         void *cpu_addr, dma_addr_t dma_addr, size_t size,
  69                         unsigned long attrs);
  70
  71 /*
  72  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
  73  * and utilize bounce buffers as needed to work around limited DMA windows.
  74  *
  75  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
  76  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
  77  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
  78  *
  79  * The following are helper functions used by the dmabounce subystem
  80  *
  81  */
  82
  83 /**
  84  * dmabounce_register_dev
  85  *
  86  * @dev: valid struct device pointer
  87  * @small_buf_size: size of buffers to use with small buffer pool
  88  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
  89  * @needs_bounce_fn: called to determine whether buffer needs bouncing
  90  *
  91  * This function should be called by low-level platform code to register
  92  * a device as requireing DMA buffer bouncing. The function will allocate
  93  * appropriate DMA pools for the device.
  94  */
  95 extern int dmabounce_register_dev(struct device *, unsigned long,
  96                 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
  97
  98 /**
  99  * dmabounce_unregister_dev
 100  *
 101  * @dev: valid struct device pointer
 102  *
 103  * This function should be called by low-level platform code when device
 104  * that was previously registered with dmabounce_register_dev is removed
 105  * from the system.
 106  *
 107  */
 108 extern void dmabounce_unregister_dev(struct device *);
 109
 110
 111
 112 /*
 113  * The scatter list versions of the above methods.
 114  */
 115 extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
 116                 enum dma_data_direction, unsigned long attrs);
 117 extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
 118                 enum dma_data_direction, unsigned long attrs);
 119 extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 120                 enum dma_data_direction);
 121 extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 122                 enum dma_data_direction);
 123 extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 124                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 125                 unsigned long attrs);
 126
 127 #endif /* __KERNEL__ */
 128 #endif