LXR linux/arch/microblaze/kernel/dma.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2009-2010 PetaLogix
   4 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
   5 *
   6 * Provide default implementations of the DMA mapping callbacks for
   7 * directly mapped busses.
   8 */
   9
  10#include <linux/device.h>
  11#include <linux/dma-mapping.h>
  12#include <linux/gfp.h>
  13#include <linux/dma-debug.h>
  14#include <linux/export.h>
  15#include <linux/bug.h>
  16
  17#define NOT_COHERENT_CACHE
  18
  19static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
  20                                       dma_addr_t *dma_handle, gfp_t flag,
  21                                       unsigned long attrs)
  22{
  23#ifdef NOT_COHERENT_CACHE
  24        return consistent_alloc(flag, size, dma_handle);
  25#else
  26        void *ret;
  27        struct page *page;
  28        int node = dev_to_node(dev);
  29
  30        /* ignore region specifiers */
  31        flag  &= ~(__GFP_HIGHMEM);
  32
  33        page = alloc_pages_node(node, flag, get_order(size));
  34        if (page == NULL)
  35                return NULL;
  36        ret = page_address(page);
  37        memset(ret, 0, size);
  38        *dma_handle = virt_to_phys(ret);
  39
  40        return ret;
  41#endif
  42}
  43
  44static void dma_direct_free_coherent(struct device *dev, size_t size,
  45                                     void *vaddr, dma_addr_t dma_handle,
  46                                     unsigned long attrs)
  47{
  48#ifdef NOT_COHERENT_CACHE
  49        consistent_free(size, vaddr);
  50#else
  51        free_pages((unsigned long)vaddr, get_order(size));
  52#endif
  53}
  54
  55static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
  56                             int nents, enum dma_data_direction direction,
  57                             unsigned long attrs)
  58{
  59        struct scatterlist *sg;
  60        int i;
  61
  62        /* FIXME this part of code is untested */
  63        for_each_sg(sgl, sg, nents, i) {
  64                sg->dma_address = sg_phys(sg);
  65
  66                if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
  67                        continue;
  68
  69                __dma_sync(sg_phys(sg), sg->length, direction);
  70        }
  71
  72        return nents;
  73}
  74
  75static int dma_direct_dma_supported(struct device *dev, u64 mask)
  76{
  77        return 1;
  78}
  79
  80static inline dma_addr_t dma_direct_map_page(struct device *dev,
  81                                             struct page *page,
  82                                             unsigned long offset,
  83                                             size_t size,
  84                                             enum dma_data_direction direction,
  85                                             unsigned long attrs)
  86{
  87        if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
  88                __dma_sync(page_to_phys(page) + offset, size, direction);
  89        return page_to_phys(page) + offset;
  90}
  91
  92static inline void dma_direct_unmap_page(struct device *dev,
  93                                         dma_addr_t dma_address,
  94                                         size_t size,
  95                                         enum dma_data_direction direction,
  96                                         unsigned long attrs)
  97{
  98/* There is not necessary to do cache cleanup
  99 *
 100 * phys_to_virt is here because in __dma_sync_page is __virt_to_phys and
 101 * dma_address is physical address
 102 */
 103        if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 104                __dma_sync(dma_address, size, direction);
 105}
 106
 107static inline void
 108dma_direct_sync_single_for_cpu(struct device *dev,
 109                               dma_addr_t dma_handle, size_t size,
 110                               enum dma_data_direction direction)
 111{
 112        /*
 113         * It's pointless to flush the cache as the memory segment
 114         * is given to the CPU
 115         */
 116
 117        if (direction == DMA_FROM_DEVICE)
 118                __dma_sync(dma_handle, size, direction);
 119}
 120
 121static inline void
 122dma_direct_sync_single_for_device(struct device *dev,
 123                                  dma_addr_t dma_handle, size_t size,
 124                                  enum dma_data_direction direction)
 125{
 126        /*
 127         * It's pointless to invalidate the cache if the device isn't
 128         * supposed to write to the relevant region
 129         */
 130
 131        if (direction == DMA_TO_DEVICE)
 132                __dma_sync(dma_handle, size, direction);
 133}
 134
 135static inline void
 136dma_direct_sync_sg_for_cpu(struct device *dev,
 137                           struct scatterlist *sgl, int nents,
 138                           enum dma_data_direction direction)
 139{
 140        struct scatterlist *sg;
 141        int i;
 142
 143        /* FIXME this part of code is untested */
 144        if (direction == DMA_FROM_DEVICE)
 145                for_each_sg(sgl, sg, nents, i)
 146                        __dma_sync(sg->dma_address, sg->length, direction);
 147}
 148
 149static inline void
 150dma_direct_sync_sg_for_device(struct device *dev,
 151                              struct scatterlist *sgl, int nents,
 152                              enum dma_data_direction direction)
 153{
 154        struct scatterlist *sg;
 155        int i;
 156
 157        /* FIXME this part of code is untested */
 158        if (direction == DMA_TO_DEVICE)
 159                for_each_sg(sgl, sg, nents, i)
 160                        __dma_sync(sg->dma_address, sg->length, direction);
 161}
 162
 163static
 164int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 165                             void *cpu_addr, dma_addr_t handle, size_t size,
 166                             unsigned long attrs)
 167{
 168#ifdef CONFIG_MMU
 169        unsigned long user_count = vma_pages(vma);
 170        unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 171        unsigned long off = vma->vm_pgoff;
 172        unsigned long pfn;
 173
 174        if (off >= count || user_count > (count - off))
 175                return -ENXIO;
 176
 177#ifdef NOT_COHERENT_CACHE
 178        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 179        pfn = consistent_virt_to_pfn(cpu_addr);
 180#else
 181        pfn = virt_to_pfn(cpu_addr);
 182#endif
 183        return remap_pfn_range(vma, vma->vm_start, pfn + off,
 184                               vma->vm_end - vma->vm_start, vma->vm_page_prot);
 185#else
 186        return -ENXIO;
 187#endif
 188}
 189
 190const struct dma_map_ops dma_direct_ops = {
 191        .alloc          = dma_direct_alloc_coherent,
 192        .free           = dma_direct_free_coherent,
 193        .mmap           = dma_direct_mmap_coherent,
 194        .map_sg         = dma_direct_map_sg,
 195        .dma_supported  = dma_direct_dma_supported,
 196        .map_page       = dma_direct_map_page,
 197        .unmap_page     = dma_direct_unmap_page,
 198        .sync_single_for_cpu            = dma_direct_sync_single_for_cpu,
 199        .sync_single_for_device         = dma_direct_sync_single_for_device,
 200        .sync_sg_for_cpu                = dma_direct_sync_sg_for_cpu,
 201        .sync_sg_for_device             = dma_direct_sync_sg_for_device,
 202};
 203EXPORT_SYMBOL(dma_direct_ops);
 204
 205/* Number of entries preallocated for DMA-API debugging */
 206#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 207
 208static int __init dma_init(void)
 209{
 210        dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 211
 212        return 0;
 213}
 214fs_initcall(dma_init);
 215