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#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
37static 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
57struct 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}
84EXPORT_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 */
90void 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}
101EXPORT_SYMBOL_GPL(free_io_pgtable_ops);
102