arch/csky/mm/dma-mapping.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/cache.h>
   5 #include <linux/dma-mapping.h>
   6 #include <linux/dma-contiguous.h>
   7 #include <linux/dma-noncoherent.h>
   8 #include <linux/genalloc.h>
   9 #include <linux/highmem.h>
  10 #include <linux/io.h>
  11 #include <linux/mm.h>
  12 #include <linux/scatterlist.h>
  13 #include <linux/types.h>
  14 #include <linux/version.h>
  15 #include <asm/cache.h>
  16
  17 void arch_dma_prep_coherent(struct page *page, size_t size)
  18 {
  19         if (PageHighMem(page)) {
  20                 unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
  21
  22                 do {
  23                         void *ptr = kmap_atomic(page);
  24                         size_t _size = (size < PAGE_SIZE) ? size : PAGE_SIZE;
  25
  26                         memset(ptr, 0, _size);
  27                         dma_wbinv_range((unsigned long)ptr,
  28                                         (unsigned long)ptr + _size);
  29
  30                         kunmap_atomic(ptr);
  31
  32                         page++;
  33                         size -= PAGE_SIZE;
  34                         count--;
  35                 } while (count);
  36         } else {
  37                 void *ptr = page_address(page);
  38
  39                 memset(ptr, 0, size);
  40                 dma_wbinv_range((unsigned long)ptr, (unsigned long)ptr + size);
  41         }
  42 }
  43
  44 static inline void cache_op(phys_addr_t paddr, size_t size,
  45                             void (*fn)(unsigned long start, unsigned long end))
  46 {
  47         struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
  48         unsigned int offset = paddr & ~PAGE_MASK;
  49         size_t left = size;
  50         unsigned long start;
  51
  52         do {
  53                 size_t len = left;
  54
  55                 if (PageHighMem(page)) {
  56                         void *addr;
  57
  58                         if (offset + len > PAGE_SIZE) {
  59                                 if (offset >= PAGE_SIZE) {
  60                                         page += offset >> PAGE_SHIFT;
  61                                         offset &= ~PAGE_MASK;
  62                                 }
  63                                 len = PAGE_SIZE - offset;
  64                         }
  65
  66                         addr = kmap_atomic(page);
  67                         start = (unsigned long)(addr + offset);
  68                         fn(start, start + len);
  69                         kunmap_atomic(addr);
  70                 } else {
  71                         start = (unsigned long)phys_to_virt(paddr);
  72                         fn(start, start + size);
  73                 }
  74                 offset = 0;
  75                 page++;
  76                 left -= len;
  77         } while (left);
  78 }
  79
  80 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
  81                               size_t size, enum dma_data_direction dir)
  82 {
  83         switch (dir) {
  84         case DMA_TO_DEVICE:
  85                 cache_op(paddr, size, dma_wb_range);
  86                 break;
  87         case DMA_FROM_DEVICE:
  88         case DMA_BIDIRECTIONAL:
  89                 cache_op(paddr, size, dma_wbinv_range);
  90                 break;
  91         default:
  92                 BUG();
  93         }
  94 }
  95
  96 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
  97                            size_t size, enum dma_data_direction dir)
  98 {
  99         switch (dir) {
 100         case DMA_TO_DEVICE:
 101                 cache_op(paddr, size, dma_wb_range);
 102                 break;
 103         case DMA_FROM_DEVICE:
 104         case DMA_BIDIRECTIONAL:
 105                 cache_op(paddr, size, dma_wbinv_range);
 106                 break;
 107         default:
 108                 BUG();
 109         }
 110 }