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 #include <asm/cacheflush.h>
  17
  18 #define NOT_COHERENT_CACHE
  19
  20 static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
  21                                        dma_addr_t *dma_handle, gfp_t flag,
  22                                        unsigned long attrs)
  23 {
  24 #ifdef NOT_COHERENT_CACHE
  25         return consistent_alloc(flag, size, dma_handle);
  26 #else
  27         void *ret;
  28         struct page *page;
  29         int node = dev_to_node(dev);
  30
  31         /* ignore region specifiers */
  32         flag  &= ~(__GFP_HIGHMEM);
  33
  34         page = alloc_pages_node(node, flag, get_order(size));
  35         if (page == NULL)
  36                 return NULL;
  37         ret = page_address(page);
  38         memset(ret, 0, size);
  39         *dma_handle = virt_to_phys(ret);
  40
  41         return ret;
  42 #endif
  43 }
  44
  45 static void dma_direct_free_coherent(struct device *dev, size_t size,
  46                                      void *vaddr, dma_addr_t dma_handle,
  47                                      unsigned long attrs)
  48 {
  49 #ifdef NOT_COHERENT_CACHE
  50         consistent_free(size, vaddr);
  51 #else
  52         free_pages((unsigned long)vaddr, get_order(size));
  53 #endif
  54 }
  55
  56 static inline void __dma_sync(unsigned long paddr,
  57                               size_t size, enum dma_data_direction direction)
  58 {
  59         switch (direction) {
  60         case DMA_TO_DEVICE:
  61         case DMA_BIDIRECTIONAL:
  62                 flush_dcache_range(paddr, paddr + size);
  63                 break;
  64         case DMA_FROM_DEVICE:
  65                 invalidate_dcache_range(paddr, paddr + size);
  66                 break;
  67         default:
  68                 BUG();
  69         }
  70 }
  71
  72 static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
  73                              int nents, enum dma_data_direction direction,
  74                              unsigned long attrs)
  75 {
  76         struct scatterlist *sg;
  77         int i;
  78
  79         /* FIXME this part of code is untested */
  80         for_each_sg(sgl, sg, nents, i) {
  81                 sg->dma_address = sg_phys(sg);
  82
  83                 if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
  84                         continue;
  85
  86                 __dma_sync(sg_phys(sg), sg->length, direction);
  87         }
  88
  89         return nents;
  90 }
  91
  92 static int dma_direct_dma_supported(struct device *dev, u64 mask)
  93 {
  94         return 1;
  95 }
  96
  97 static inline dma_addr_t dma_direct_map_page(struct device *dev,
  98                                              struct page *page,
  99                                              unsigned long offset,
 100                                              size_t size,
 101                                              enum dma_data_direction direction,
 102                                              unsigned long attrs)
 103 {
 104         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 105                 __dma_sync(page_to_phys(page) + offset, size, direction);
 106         return page_to_phys(page) + offset;
 107 }
 108
 109 static inline void dma_direct_unmap_page(struct device *dev,
 110                                          dma_addr_t dma_address,
 111                                          size_t size,
 112                                          enum dma_data_direction direction,
 113                                          unsigned long attrs)
 114 {
 115 /* There is not necessary to do cache cleanup
 116  *
 117  * phys_to_virt is here because in __dma_sync_page is __virt_to_phys and
 118  * dma_address is physical address
 119  */
 120         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 121                 __dma_sync(dma_address, size, direction);
 122 }
 123
 124 static inline void
 125 dma_direct_sync_single_for_cpu(struct device *dev,
 126                                dma_addr_t dma_handle, size_t size,
 127                                enum dma_data_direction direction)
 128 {
 129         /*
 130          * It's pointless to flush the cache as the memory segment
 131          * is given to the CPU
 132          */
 133
 134         if (direction == DMA_FROM_DEVICE)
 135                 __dma_sync(dma_handle, size, direction);
 136 }
 137
 138 static inline void
 139 dma_direct_sync_single_for_device(struct device *dev,
 140                                   dma_addr_t dma_handle, size_t size,
 141                                   enum dma_data_direction direction)
 142 {
 143         /*
 144          * It's pointless to invalidate the cache if the device isn't
 145          * supposed to write to the relevant region
 146          */
 147
 148         if (direction == DMA_TO_DEVICE)
 149                 __dma_sync(dma_handle, size, direction);
 150 }
 151
 152 static inline void
 153 dma_direct_sync_sg_for_cpu(struct device *dev,
 154                            struct scatterlist *sgl, int nents,
 155                            enum dma_data_direction direction)
 156 {
 157         struct scatterlist *sg;
 158         int i;
 159
 160         /* FIXME this part of code is untested */
 161         if (direction == DMA_FROM_DEVICE)
 162                 for_each_sg(sgl, sg, nents, i)
 163                         __dma_sync(sg->dma_address, sg->length, direction);
 164 }
 165
 166 static inline void
 167 dma_direct_sync_sg_for_device(struct device *dev,
 168                               struct scatterlist *sgl, int nents,
 169                               enum dma_data_direction direction)
 170 {
 171         struct scatterlist *sg;
 172         int i;
 173
 174         /* FIXME this part of code is untested */
 175         if (direction == DMA_TO_DEVICE)
 176                 for_each_sg(sgl, sg, nents, i)
 177                         __dma_sync(sg->dma_address, sg->length, direction);
 178 }
 179
 180 static
 181 int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 182                              void *cpu_addr, dma_addr_t handle, size_t size,
 183                              unsigned long attrs)
 184 {
 185 #ifdef CONFIG_MMU
 186         unsigned long user_count = vma_pages(vma);
 187         unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 188         unsigned long off = vma->vm_pgoff;
 189         unsigned long pfn;
 190
 191         if (off >= count || user_count > (count - off))
 192                 return -ENXIO;
 193
 194 #ifdef NOT_COHERENT_CACHE
 195         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 196         pfn = consistent_virt_to_pfn(cpu_addr);
 197 #else
 198         pfn = virt_to_pfn(cpu_addr);
 199 #endif
 200         return remap_pfn_range(vma, vma->vm_start, pfn + off,
 201                                vma->vm_end - vma->vm_start, vma->vm_page_prot);
 202 #else
 203         return -ENXIO;
 204 #endif
 205 }
 206
 207 const struct dma_map_ops dma_direct_ops = {
 208         .alloc          = dma_direct_alloc_coherent,
 209         .free           = dma_direct_free_coherent,
 210         .mmap           = dma_direct_mmap_coherent,
 211         .map_sg         = dma_direct_map_sg,
 212         .dma_supported  = dma_direct_dma_supported,
 213         .map_page       = dma_direct_map_page,
 214         .unmap_page     = dma_direct_unmap_page,
 215         .sync_single_for_cpu            = dma_direct_sync_single_for_cpu,
 216         .sync_single_for_device         = dma_direct_sync_single_for_device,
 217         .sync_sg_for_cpu                = dma_direct_sync_sg_for_cpu,
 218         .sync_sg_for_device             = dma_direct_sync_sg_for_device,
 219 };
 220 EXPORT_SYMBOL(dma_direct_ops);
 221
 222 /* Number of entries preallocated for DMA-API debugging */
 223 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 224
 225 static int __init dma_init(void)
 226 {
 227         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 228
 229         return 0;
 230 }
 231 fs_initcall(dma_init);