1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Generic page table allocator for IOMMUs.
4 *
5 * Copyright (C) 2014 ARM Limited
6 *
7 * Author: Will Deacon <will.deacon@arm.com>
8 */
9
10 #include <linux/bug.h>
11 #include <linux/io-pgtable.h>
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14
15 static const struct io_pgtable_init_fns *
16 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
17 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
18 [ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
19 [ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
20 [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
21 [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
22 [ARM_MALI_LPAE] = &io_pgtable_arm_mali_lpae_init_fns,
23 #endif
24 #ifdef CONFIG_IOMMU_IO_PGTABLE_DART
25 [APPLE_DART] = &io_pgtable_apple_dart_init_fns,
26 [APPLE_DART2] = &io_pgtable_apple_dart_init_fns,
27 #endif
28 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
29 [ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
30 #endif
31 #ifdef CONFIG_AMD_IOMMU
32 [AMD_IOMMU_V1] = &io_pgtable_amd_iommu_v1_init_fns,
33 [AMD_IOMMU_V2] = &io_pgtable_amd_iommu_v2_init_fns,
34 #endif
35 };
36
check_custom_allocator(enum io_pgtable_fmt fmt,struct io_pgtable_cfg * cfg)37 static int check_custom_allocator(enum io_pgtable_fmt fmt,
38 struct io_pgtable_cfg *cfg)
39 {
40 /* No custom allocator, no need to check the format. */
41 if (!cfg->alloc && !cfg->free)
42 return 0;
43
44 /* When passing a custom allocator, both the alloc and free
45 * functions should be provided.
46 */
47 if (!cfg->alloc || !cfg->free)
48 return -EINVAL;
49
50 /* Make sure the format supports custom allocators. */
51 if (io_pgtable_init_table[fmt]->caps & IO_PGTABLE_CAP_CUSTOM_ALLOCATOR)
52 return 0;
53
54 return -EINVAL;
55 }
56
alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,struct io_pgtable_cfg * cfg,void * cookie)57 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
58 struct io_pgtable_cfg *cfg,
59 void *cookie)
60 {
61 struct io_pgtable *iop;
62 const struct io_pgtable_init_fns *fns;
63
64 if (fmt >= IO_PGTABLE_NUM_FMTS)
65 return NULL;
66
67 if (check_custom_allocator(fmt, cfg))
68 return NULL;
69
70 fns = io_pgtable_init_table[fmt];
71 if (!fns)
72 return NULL;
73
74 iop = fns->alloc(cfg, cookie);
75 if (!iop)
76 return NULL;
77
78 iop->fmt = fmt;
79 iop->cookie = cookie;
80 iop->cfg = *cfg;
81
82 return &iop->ops;
83 }
84 EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops);
85
86 /*
87 * It is the IOMMU driver's responsibility to ensure that the page table
88 * is no longer accessible to the walker by this point.
89 */
free_io_pgtable_ops(struct io_pgtable_ops * ops)90 void free_io_pgtable_ops(struct io_pgtable_ops *ops)
91 {
92 struct io_pgtable *iop;
93
94 if (!ops)
95 return;
96
97 iop = io_pgtable_ops_to_pgtable(ops);
98 io_pgtable_tlb_flush_all(iop);
99 io_pgtable_init_table[iop->fmt]->free(iop);
100 }
101 EXPORT_SYMBOL_GPL(free_io_pgtable_ops);
102