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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/init.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
17void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
18 dma_addr_t *dma_handle, gfp_t flags,
19 unsigned long attrs)
20{
21 void *vaddr;
22
23 /*
24 * Don't print a warning when the first allocation attempt fails.
25 * swiotlb_alloc_coherent() will print a warning when the DMA
26 * memory allocation ultimately failed.
27 */
28 flags |= __GFP_NOWARN;
29
30 vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags,
31 attrs);
32 if (vaddr)
33 return vaddr;
34
35 return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
36}
37
38void x86_swiotlb_free_coherent(struct device *dev, size_t size,
39 void *vaddr, dma_addr_t dma_addr,
40 unsigned long attrs)
41{
42 if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr)))
43 swiotlb_free_coherent(dev, size, vaddr, dma_addr);
44 else
45 dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
46}
47
48static struct dma_map_ops swiotlb_dma_ops = {
49 .mapping_error = swiotlb_dma_mapping_error,
50 .alloc = x86_swiotlb_alloc_coherent,
51 .free = x86_swiotlb_free_coherent,
52 .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
53 .sync_single_for_device = swiotlb_sync_single_for_device,
54 .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
55 .sync_sg_for_device = swiotlb_sync_sg_for_device,
56 .map_sg = swiotlb_map_sg_attrs,
57 .unmap_sg = swiotlb_unmap_sg_attrs,
58 .map_page = swiotlb_map_page,
59 .unmap_page = swiotlb_unmap_page,
60 .dma_supported = NULL,
61};
62
63/*
64 * pci_swiotlb_detect_override - set swiotlb to 1 if necessary
65 *
66 * This returns non-zero if we are forced to use swiotlb (by the boot
67 * option).
68 */
69int __init pci_swiotlb_detect_override(void)
70{
71 if (swiotlb_force == SWIOTLB_FORCE)
72 swiotlb = 1;
73
74 return swiotlb;
75}
76IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
77 pci_xen_swiotlb_detect,
78 pci_swiotlb_init,
79 pci_swiotlb_late_init);
80
81/*
82 * if 4GB or more detected (and iommu=off not set) return 1
83 * and set swiotlb to 1.
84 */
85int __init pci_swiotlb_detect_4gb(void)
86{
87 /* don't initialize swiotlb if iommu=off (no_iommu=1) */
88#ifdef CONFIG_X86_64
89 if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
90 swiotlb = 1;
91#endif
92 return swiotlb;
93}
94IOMMU_INIT(pci_swiotlb_detect_4gb,
95 pci_swiotlb_detect_override,
96 pci_swiotlb_init,
97 pci_swiotlb_late_init);
98
99void __init pci_swiotlb_init(void)
100{
101 if (swiotlb) {
102 swiotlb_init(0);
103 dma_ops = &swiotlb_dma_ops;
104 }
105}
106
107void __init pci_swiotlb_late_init(void)
108{
109 /* An IOMMU turned us off. */
110 if (!swiotlb)
111 swiotlb_free();
112 else {
113 printk(KERN_INFO "PCI-DMA: "
114 "Using software bounce buffering for IO (SWIOTLB)\n");
115 swiotlb_print_info();
116 }
117}