xref: /openbmc/linux/drivers/iommu/io-pgtable.c (revision 43ffe817)
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_ARMV7S
25 	[ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
26 #endif
27 };
28 
29 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
30 					    struct io_pgtable_cfg *cfg,
31 					    void *cookie)
32 {
33 	struct io_pgtable *iop;
34 	const struct io_pgtable_init_fns *fns;
35 
36 	if (fmt >= IO_PGTABLE_NUM_FMTS)
37 		return NULL;
38 
39 	fns = io_pgtable_init_table[fmt];
40 	if (!fns)
41 		return NULL;
42 
43 	iop = fns->alloc(cfg, cookie);
44 	if (!iop)
45 		return NULL;
46 
47 	iop->fmt	= fmt;
48 	iop->cookie	= cookie;
49 	iop->cfg	= *cfg;
50 
51 	return &iop->ops;
52 }
53 EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops);
54 
55 /*
56  * It is the IOMMU driver's responsibility to ensure that the page table
57  * is no longer accessible to the walker by this point.
58  */
59 void free_io_pgtable_ops(struct io_pgtable_ops *ops)
60 {
61 	struct io_pgtable *iop;
62 
63 	if (!ops)
64 		return;
65 
66 	iop = io_pgtable_ops_to_pgtable(ops);
67 	io_pgtable_tlb_flush_all(iop);
68 	io_pgtable_init_table[iop->fmt]->free(iop);
69 }
70 EXPORT_SYMBOL_GPL(free_io_pgtable_ops);
71