1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_IOMMU_TABLE_H
3 #define _ASM_X86_IOMMU_TABLE_H
4
5 #include <asm/swiotlb.h>
6
7 /*
8 * History lesson:
9 * The execution chain of IOMMUs in 2.6.36 looks as so:
10 *
11 * [xen-swiotlb]
12 * |
13 * +----[swiotlb *]--+
14 * / | \
15 * / | \
16 * [GART] [Calgary] [Intel VT-d]
17 * /
18 * /
19 * [AMD-Vi]
20 *
21 * *: if SWIOTLB detected 'iommu=soft'/'swiotlb=force' it would skip
22 * over the rest of IOMMUs and unconditionally initialize the SWIOTLB.
23 * Also it would surreptitiously initialize set the swiotlb=1 if there were
24 * more than 4GB and if the user did not pass in 'iommu=off'. The swiotlb
25 * flag would be turned off by all IOMMUs except the Calgary one.
26 *
27 * The IOMMU_INIT* macros allow a similar tree (or more complex if desired)
28 * to be built by defining who we depend on.
29 *
30 * And all that needs to be done is to use one of the macros in the IOMMU
31 * and the pci-dma.c will take care of the rest.
32 */
33
34 struct iommu_table_entry {
35 initcall_t detect;
36 initcall_t depend;
37 void (*early_init)(void); /* No memory allocate available. */
38 void (*late_init)(void); /* Yes, can allocate memory. */
39 #define IOMMU_FINISH_IF_DETECTED (1<<0)
40 #define IOMMU_DETECTED (1<<1)
41 int flags;
42 };
43 /*
44 * Macro fills out an entry in the .iommu_table that is equivalent
45 * to the fields that 'struct iommu_table_entry' has. The entries
46 * that are put in the .iommu_table section are not put in any order
47 * hence during boot-time we will have to resort them based on
48 * dependency. */
49
50
51 #define __IOMMU_INIT(_detect, _depend, _early_init, _late_init, _finish)\
52 static const struct iommu_table_entry \
53 __iommu_entry_##_detect __used \
54 __attribute__ ((unused, __section__(".iommu_table"), \
55 aligned((sizeof(void *))))) \
56 = {_detect, _depend, _early_init, _late_init, \
57 _finish ? IOMMU_FINISH_IF_DETECTED : 0}
58 /*
59 * The simplest IOMMU definition. Provide the detection routine
60 * and it will be run after the SWIOTLB and the other IOMMUs
61 * that utilize this macro. If the IOMMU is detected (ie, the
62 * detect routine returns a positive value), the other IOMMUs
63 * are also checked. You can use IOMMU_INIT_POST_FINISH if you prefer
64 * to stop detecting the other IOMMUs after yours has been detected.
65 */
66 #define IOMMU_INIT_POST(_detect) \
67 __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, NULL, NULL, 0)
68
69 #define IOMMU_INIT_POST_FINISH(detect) \
70 __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, NULL, NULL, 1)
71
72 /*
73 * A more sophisticated version of IOMMU_INIT. This variant requires:
74 * a). A detection routine function.
75 * b). The name of the detection routine we depend on to get called
76 * before us.
77 * c). The init routine which gets called if the detection routine
78 * returns a positive value from the pci_iommu_alloc. This means
79 * no presence of a memory allocator.
80 * d). Similar to the 'init', except that this gets called from pci_iommu_init
81 * where we do have a memory allocator.
82 *
83 * The standard IOMMU_INIT differs from the IOMMU_INIT_FINISH variant
84 * in that the former will continue detecting other IOMMUs in the call
85 * list after the detection routine returns a positive number, while the
86 * latter will stop the execution chain upon first successful detection.
87 * Both variants will still call the 'init' and 'late_init' functions if
88 * they are set.
89 */
90 #define IOMMU_INIT_FINISH(_detect, _depend, _init, _late_init) \
91 __IOMMU_INIT(_detect, _depend, _init, _late_init, 1)
92
93 #define IOMMU_INIT(_detect, _depend, _init, _late_init) \
94 __IOMMU_INIT(_detect, _depend, _init, _late_init, 0)
95
96 void sort_iommu_table(struct iommu_table_entry *start,
97 struct iommu_table_entry *finish);
98
99 void check_iommu_entries(struct iommu_table_entry *start,
100 struct iommu_table_entry *finish);
101
102 #endif /* _ASM_X86_IOMMU_TABLE_H */