Linux kernel mirror (for testing)
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linux
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
15static const struct io_pgtable_init_fns *
16io_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};
32
33static int check_custom_allocator(enum io_pgtable_fmt fmt,
34 struct io_pgtable_cfg *cfg)
35{
36 /* No custom allocator, no need to check the format. */
37 if (!cfg->alloc && !cfg->free)
38 return 0;
39
40 /* When passing a custom allocator, both the alloc and free
41 * functions should be provided.
42 */
43 if (!cfg->alloc || !cfg->free)
44 return -EINVAL;
45
46 /* Make sure the format supports custom allocators. */
47 if (io_pgtable_init_table[fmt]->caps & IO_PGTABLE_CAP_CUSTOM_ALLOCATOR)
48 return 0;
49
50 return -EINVAL;
51}
52
53struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
54 struct io_pgtable_cfg *cfg,
55 void *cookie)
56{
57 struct io_pgtable *iop;
58 const struct io_pgtable_init_fns *fns;
59
60 if (fmt >= IO_PGTABLE_NUM_FMTS)
61 return NULL;
62
63 if (check_custom_allocator(fmt, cfg))
64 return NULL;
65
66 fns = io_pgtable_init_table[fmt];
67 if (!fns)
68 return NULL;
69
70 iop = fns->alloc(cfg, cookie);
71 if (!iop)
72 return NULL;
73
74 iop->fmt = fmt;
75 iop->cookie = cookie;
76 iop->cfg = *cfg;
77
78 return &iop->ops;
79}
80EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops);
81
82/*
83 * It is the IOMMU driver's responsibility to ensure that the page table
84 * is no longer accessible to the walker by this point.
85 */
86void free_io_pgtable_ops(struct io_pgtable_ops *ops)
87{
88 struct io_pgtable *iop;
89
90 if (!ops)
91 return;
92
93 iop = io_pgtable_ops_to_pgtable(ops);
94 io_pgtable_tlb_flush_all(iop);
95 io_pgtable_init_table[iop->fmt]->free(iop);
96}
97EXPORT_SYMBOL_GPL(free_io_pgtable_ops);