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
  12 void 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  */
  39 static int __init hexagon_dma_init(void)
  40 {
  41         return dma_init_global_coherent(PFN_PHYS(max_low_pfn),
  42                                         hexagon_coherent_pool_size);
  43 }
  44 core_initcall(hexagon_dma_init);