1// SPDX-License-Identifier: GPL-2.0
 2
 3#include <linux/pci.h>
 4#include <linux/cache.h>
 5#include <linux/init.h>
 6#include <linux/swiotlb.h>
 7#include <linux/memblock.h>
 8#include <linux/dma-direct.h>
 9#include <linux/mem_encrypt.h>
10
11#include <asm/iommu.h>
12#include <asm/swiotlb.h>
13#include <asm/dma.h>
14#include <asm/xen/swiotlb-xen.h>
15#include <asm/iommu_table.h>
16
17int swiotlb __read_mostly;
18
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
19/*
20 * pci_swiotlb_detect_override - set swiotlb to 1 if necessary
21 *
22 * This returns non-zero if we are forced to use swiotlb (by the boot
23 * option).
24 */
25int __init pci_swiotlb_detect_override(void)
26{
27	if (swiotlb_force == SWIOTLB_FORCE)
 
 
28		swiotlb = 1;
29
30	return swiotlb;
31}
32IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
33		  pci_xen_swiotlb_detect,
34		  pci_swiotlb_init,
35		  pci_swiotlb_late_init);
36
37/*
38 * If 4GB or more detected (and iommu=off not set) or if SME is active
39 * then set swiotlb to 1 and return 1.
40 */
41int __init pci_swiotlb_detect_4gb(void)
42{
43	/* don't initialize swiotlb if iommu=off (no_iommu=1) */
44	if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
 
45		swiotlb = 1;
46
47	/*
48	 * If SME is active then swiotlb will be set to 1 so that bounce
49	 * buffers are allocated and used for devices that do not support
50	 * the addressing range required for the encryption mask.
51	 */
52	if (sme_active())
53		swiotlb = 1;
54
55	return swiotlb;
56}
57IOMMU_INIT(pci_swiotlb_detect_4gb,
58	   pci_swiotlb_detect_override,
59	   pci_swiotlb_init,
60	   pci_swiotlb_late_init);
61
62void __init pci_swiotlb_init(void)
63{
64	if (swiotlb)
65		swiotlb_init(0);
 
 
66}
67
68void __init pci_swiotlb_late_init(void)
69{
70	/* An IOMMU turned us off. */
71	if (!swiotlb)
72		swiotlb_exit();
73	else {
74		printk(KERN_INFO "PCI-DMA: "
75		       "Using software bounce buffering for IO (SWIOTLB)\n");
76		swiotlb_print_info();
77	}
78}

  1/* Glue code to lib/swiotlb.c */
  2
  3#include <linux/pci.h>
  4#include <linux/cache.h>
  5#include <linux/module.h>
  6#include <linux/swiotlb.h>
  7#include <linux/bootmem.h>
  8#include <linux/dma-mapping.h>
 
  9
 10#include <asm/iommu.h>
 11#include <asm/swiotlb.h>
 12#include <asm/dma.h>
 13#include <asm/xen/swiotlb-xen.h>
 14#include <asm/iommu_table.h>
 
 15int swiotlb __read_mostly;
 16
 17static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 18					dma_addr_t *dma_handle, gfp_t flags)
 19{
 20	void *vaddr;
 21
 22	vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
 23	if (vaddr)
 24		return vaddr;
 25
 26	return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
 27}
 28
 29static struct dma_map_ops swiotlb_dma_ops = {
 30	.mapping_error = swiotlb_dma_mapping_error,
 31	.alloc_coherent = x86_swiotlb_alloc_coherent,
 32	.free_coherent = swiotlb_free_coherent,
 33	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
 34	.sync_single_for_device = swiotlb_sync_single_for_device,
 35	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
 36	.sync_sg_for_device = swiotlb_sync_sg_for_device,
 37	.map_sg = swiotlb_map_sg_attrs,
 38	.unmap_sg = swiotlb_unmap_sg_attrs,
 39	.map_page = swiotlb_map_page,
 40	.unmap_page = swiotlb_unmap_page,
 41	.dma_supported = NULL,
 42};
 43
 44/*
 45 * pci_swiotlb_detect_override - set swiotlb to 1 if necessary
 46 *
 47 * This returns non-zero if we are forced to use swiotlb (by the boot
 48 * option).
 49 */
 50int __init pci_swiotlb_detect_override(void)
 51{
 52	int use_swiotlb = swiotlb | swiotlb_force;
 53
 54	if (swiotlb_force)
 55		swiotlb = 1;
 56
 57	return use_swiotlb;
 58}
 59IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
 60		  pci_xen_swiotlb_detect,
 61		  pci_swiotlb_init,
 62		  pci_swiotlb_late_init);
 63
 64/*
 65 * if 4GB or more detected (and iommu=off not set) return 1
 66 * and set swiotlb to 1.
 67 */
 68int __init pci_swiotlb_detect_4gb(void)
 69{
 70	/* don't initialize swiotlb if iommu=off (no_iommu=1) */
 71#ifdef CONFIG_X86_64
 72	if (!no_iommu && max_pfn > MAX_DMA32_PFN)
 73		swiotlb = 1;
 74#endif
 
 
 
 
 
 
 
 
 75	return swiotlb;
 76}
 77IOMMU_INIT(pci_swiotlb_detect_4gb,
 78	   pci_swiotlb_detect_override,
 79	   pci_swiotlb_init,
 80	   pci_swiotlb_late_init);
 81
 82void __init pci_swiotlb_init(void)
 83{
 84	if (swiotlb) {
 85		swiotlb_init(0);
 86		dma_ops = &swiotlb_dma_ops;
 87	}
 88}
 89
 90void __init pci_swiotlb_late_init(void)
 91{
 92	/* An IOMMU turned us off. */
 93	if (!swiotlb)
 94		swiotlb_free();
 95	else {
 96		printk(KERN_INFO "PCI-DMA: "
 97		       "Using software bounce buffering for IO (SWIOTLB)\n");
 98		swiotlb_print_info();
 99	}
100}