arch/ia64/kernel/pci-dma.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Dynamic DMA mapping support.
   4  */
   5
   6 #include <linux/types.h>
   7 #include <linux/mm.h>
   8 #include <linux/string.h>
   9 #include <linux/pci.h>
  10 #include <linux/module.h>
  11 #include <linux/dmar.h>
  12 #include <asm/iommu.h>
  13 #include <asm/machvec.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/kernel.h>
  16 #include <asm/page.h>
  17
  18 int no_iommu __read_mostly;
  19 #ifdef CONFIG_IOMMU_DEBUG
  20 int force_iommu __read_mostly = 1;
  21 #else
  22 int force_iommu __read_mostly;
  23 #endif
  24
  25 int iommu_pass_through;
  26
  27 static int __init pci_iommu_init(void)
  28 {
  29         if (iommu_detected)
  30                 intel_iommu_init();
  31
  32         return 0;
  33 }
  34
  35 /* Must execute after PCI subsystem */
  36 fs_initcall(pci_iommu_init);
  37
  38 void __init pci_iommu_alloc(void)
  39 {
  40         /*
  41          * The order of these functions is important for
  42          * fall-back/fail-over reasons
  43          */
  44         detect_intel_iommu();
  45
  46 #ifdef CONFIG_SWIOTLB
  47         if (!iommu_detected) {
  48 #ifdef CONFIG_IA64_GENERIC
  49                 printk(KERN_INFO "PCI-DMA: Re-initialize machine vector.\n");
  50                 machvec_init("dig");
  51                 swiotlb_dma_init();
  52 #else
  53                 panic("Unable to find Intel IOMMU");
  54 #endif /* CONFIG_IA64_GENERIC */
  55         }
  56 #endif /* CONFIG_SWIOTLB */
  57 }