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-map-ops.h>
   6 #include <linux/genalloc.h>
   7 #include <linux/highmem.h>
   8 #include <linux/io.h>
   9 #include <linux/mm.h>
  10 #include <linux/scatterlist.h>
  11 #include <linux/types.h>
  12 #include <linux/version.h>
  13 #include <asm/cache.h>
  14
  15 static inline void cache_op(phys_addr_t paddr, size_t size,
  16                             void (*fn)(unsigned long start, unsigned long end))
  17 {
  18         struct page *page    = phys_to_page(paddr);
  19         void *start          = __va(page_to_phys(page));
  20         unsigned long offset = offset_in_page(paddr);
  21         size_t left          = size;
  22
  23         do {
  24                 size_t len = left;
  25
  26                 if (offset + len > PAGE_SIZE)
  27                         len = PAGE_SIZE - offset;
  28
  29                 if (PageHighMem(page)) {
  30                         start = kmap_atomic(page);
  31
  32                         fn((unsigned long)start + offset,
  33                                         (unsigned long)start + offset + len);
  34
  35                         kunmap_atomic(start);
  36                 } else {
  37                         fn((unsigned long)start + offset,
  38                                         (unsigned long)start + offset + len);
  39                 }
  40                 offset = 0;
  41
  42                 page++;
  43                 start += PAGE_SIZE;
  44                 left -= len;
  45         } while (left);
  46 }
  47
  48 static void dma_wbinv_set_zero_range(unsigned long start, unsigned long end)
  49 {
  50         memset((void *)start, 0, end - start);
  51         dma_wbinv_range(start, end);
  52 }
  53
  54 void arch_dma_prep_coherent(struct page *page, size_t size)
  55 {
  56         cache_op(page_to_phys(page), size, dma_wbinv_set_zero_range);
  57 }
  58
  59 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
  60                 enum dma_data_direction dir)
  61 {
  62         switch (dir) {
  63         case DMA_TO_DEVICE:
  64                 cache_op(paddr, size, dma_wb_range);
  65                 break;
  66         case DMA_FROM_DEVICE:
  67         case DMA_BIDIRECTIONAL:
  68                 cache_op(paddr, size, dma_wbinv_range);
  69                 break;
  70         default:
  71                 BUG();
  72         }
  73 }
  74
  75 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
  76                 enum dma_data_direction dir)
  77 {
  78         switch (dir) {
  79         case DMA_TO_DEVICE:
  80                 return;
  81         case DMA_FROM_DEVICE:
  82         case DMA_BIDIRECTIONAL:
  83                 cache_op(paddr, size, dma_inv_range);
  84                 break;
  85         default:
  86                 BUG();
  87         }
  88 }