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
  19 static 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
  44 static 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
  55 static 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
  75 static int dma_direct_dma_supported(struct device *dev, u64 mask)
  76 {
  77         return 1;
  78 }
  79
  80 static 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
  92 static 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
 107 static inline void
 108 dma_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
 121 static inline void
 122 dma_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
 135 static inline void
 136 dma_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
 149 static inline void
 150 dma_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
 163 static
 164 int 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
 190 const 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 };
 203 EXPORT_SYMBOL(dma_direct_ops);
 204
 205 /* Number of entries preallocated for DMA-API debugging */
 206 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 207
 208 static int __init dma_init(void)
 209 {
 210         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 211
 212         return 0;
 213 }
 214 fs_initcall(dma_init);