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-noncoherent.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 static void __dma_sync(struct device *dev, phys_addr_t paddr, size_t size,
  19                 enum dma_data_direction direction)
  20 {
  21         switch (direction) {
  22         case DMA_TO_DEVICE:
  23         case DMA_BIDIRECTIONAL:
  24                 flush_dcache_range(paddr, paddr + size);
  25                 break;
  26         case DMA_FROM_DEVICE:
  27                 invalidate_dcache_range(paddr, paddr + size);
  28                 break;
  29         default:
  30                 BUG();
  31         }
  32 }
  33
  34 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
  35                 size_t size, enum dma_data_direction dir)
  36 {
  37         __dma_sync(dev, paddr, size, dir);
  38 }
  39
  40 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
  41                 size_t size, enum dma_data_direction dir)
  42 {
  43         __dma_sync(dev, paddr, size, dir);
  44 }
  45
  46 int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma,
  47                 void *cpu_addr, dma_addr_t handle, size_t size,
  48                 unsigned long attrs)
  49 {
  50 #ifdef CONFIG_MMU
  51         unsigned long user_count = vma_pages(vma);
  52         unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
  53         unsigned long off = vma->vm_pgoff;
  54         unsigned long pfn;
  55
  56         if (off >= count || user_count > (count - off))
  57                 return -ENXIO;
  58
  59         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
  60         pfn = consistent_virt_to_pfn(cpu_addr);
  61         return remap_pfn_range(vma, vma->vm_start, pfn + off,
  62                                vma->vm_end - vma->vm_start, vma->vm_page_prot);
  63 #else
  64         return -ENXIO;
  65 #endif
  66 }