LXR linux/arch/hexagon/kernel/dma.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * DMA implementation for Hexagon
   4 *
   5 * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
   6 */
   7
   8#include <linux/dma-map-ops.h>
   9#include <linux/memblock.h>
  10#include <asm/page.h>
  11
  12void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
  13                enum dma_data_direction dir)
  14{
  15        void *addr = phys_to_virt(paddr);
  16
  17        switch (dir) {
  18        case DMA_TO_DEVICE:
  19                hexagon_clean_dcache_range((unsigned long) addr,
  20                (unsigned long) addr + size);
  21                break;
  22        case DMA_FROM_DEVICE:
  23                hexagon_inv_dcache_range((unsigned long) addr,
  24                (unsigned long) addr + size);
  25                break;
  26        case DMA_BIDIRECTIONAL:
  27                flush_dcache_range((unsigned long) addr,
  28                (unsigned long) addr + size);
  29                break;
  30        default:
  31                BUG();
  32        }
  33}
  34
  35/*
  36 * Our max_low_pfn should have been backed off by 16MB in mm/init.c to create
  37 * DMA coherent space.  Use that for the pool.
  38 */
  39static int __init hexagon_dma_init(void)
  40{
  41        return dma_init_global_coherent(PFN_PHYS(max_low_pfn),
  42                                        hexagon_coherent_pool_size);
  43}
  44core_initcall(hexagon_dma_init);
  45