arch/powerpc/kernel/dma-swiotlb.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Contains routines needed to support swiotlb for ppc.
   4  *
   5  * Copyright (C) 2009-2010 Freescale Semiconductor, Inc.
   6  * Author: Becky Bruce
   7  */
   8 #include <linux/memblock.h>
   9 #include <asm/machdep.h>
  10 #include <asm/swiotlb.h>
  11
  12 unsigned int ppc_swiotlb_enable;
  13
  14 void __init swiotlb_detect_4g(void)
  15 {
  16         if ((memblock_end_of_DRAM() - 1) > 0xffffffff)
  17                 ppc_swiotlb_enable = 1;
  18 }
  19
  20 static int __init check_swiotlb_enabled(void)
  21 {
  22         if (ppc_swiotlb_enable)
  23                 swiotlb_print_info();
  24         else
  25                 swiotlb_exit();
  26
  27         return 0;
  28 }
  29 subsys_initcall(check_swiotlb_enabled);