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