arch/nios2/mm/dma-mapping.c

   1 /*
   2  * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
   3  * Copyright (C) 2009 Wind River Systems Inc
   4  *  Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
   5  *
   6  * Based on DMA code from MIPS.
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12
  13 #include <linux/types.h>
  14 #include <linux/mm.h>
  15 #include <linux/string.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/io.h>
  18 #include <linux/cache.h>
  19 #include <asm/cacheflush.h>
  20
  21 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
  22                 enum dma_data_direction dir)
  23 {
  24         void *vaddr = phys_to_virt(paddr);
  25
  26         switch (dir) {
  27         case DMA_FROM_DEVICE:
  28                 invalidate_dcache_range((unsigned long)vaddr,
  29                         (unsigned long)(vaddr + size));
  30                 break;
  31         case DMA_TO_DEVICE:
  32                 /*
  33                  * We just need to flush the caches here , but Nios2 flush
  34                  * instruction will do both writeback and invalidate.
  35                  */
  36         case DMA_BIDIRECTIONAL: /* flush and invalidate */
  37                 flush_dcache_range((unsigned long)vaddr,
  38                         (unsigned long)(vaddr + size));
  39                 break;
  40         default:
  41                 BUG();
  42         }
  43 }
  44
  45 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
  46                 enum dma_data_direction dir)
  47 {
  48         void *vaddr = phys_to_virt(paddr);
  49
  50         switch (dir) {
  51         case DMA_BIDIRECTIONAL:
  52         case DMA_FROM_DEVICE:
  53                 invalidate_dcache_range((unsigned long)vaddr,
  54                         (unsigned long)(vaddr + size));
  55                 break;
  56         case DMA_TO_DEVICE:
  57                 break;
  58         default:
  59                 BUG();
  60         }
  61 }
  62
  63 void arch_dma_prep_coherent(struct page *page, size_t size)
  64 {
  65         unsigned long start = (unsigned long)page_address(page);
  66
  67         flush_dcache_range(start, start + size);
  68 }
  69
  70 void *uncached_kernel_address(void *ptr)
  71 {
  72         unsigned long addr = (unsigned long)ptr;
  73
  74         addr |= CONFIG_NIOS2_IO_REGION_BASE;
  75
  76         return (void *)ptr;
  77 }
  78
  79 void *cached_kernel_address(void *ptr)
  80 {
  81         unsigned long addr = (unsigned long)ptr;
  82
  83         addr &= ~CONFIG_NIOS2_IO_REGION_BASE;
  84         addr |= CONFIG_NIOS2_KERNEL_REGION_BASE;
  85
  86         return (void *)ptr;
  87 }