xref: /openbmc/linux/drivers/iommu/io-pgtable.c (revision 07c7c6bf)
1 /*
2  * Generic page table allocator for IOMMUs.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  *
16  * Copyright (C) 2014 ARM Limited
17  *
18  * Author: Will Deacon <will.deacon@arm.com>
19  */
20 
21 #include <linux/bug.h>
22 #include <linux/io-pgtable.h>
23 #include <linux/kernel.h>
24 #include <linux/types.h>
25 
26 static const struct io_pgtable_init_fns *
27 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
28 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
29 	[ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
30 	[ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
31 	[ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
32 	[ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
33 	[ARM_MALI_LPAE] = &io_pgtable_arm_mali_lpae_init_fns,
34 #endif
35 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
36 	[ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
37 #endif
38 };
39 
40 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
41 					    struct io_pgtable_cfg *cfg,
42 					    void *cookie)
43 {
44 	struct io_pgtable *iop;
45 	const struct io_pgtable_init_fns *fns;
46 
47 	if (fmt >= IO_PGTABLE_NUM_FMTS)
48 		return NULL;
49 
50 	fns = io_pgtable_init_table[fmt];
51 	if (!fns)
52 		return NULL;
53 
54 	iop = fns->alloc(cfg, cookie);
55 	if (!iop)
56 		return NULL;
57 
58 	iop->fmt	= fmt;
59 	iop->cookie	= cookie;
60 	iop->cfg	= *cfg;
61 
62 	return &iop->ops;
63 }
64 EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops);
65 
66 /*
67  * It is the IOMMU driver's responsibility to ensure that the page table
68  * is no longer accessible to the walker by this point.
69  */
70 void free_io_pgtable_ops(struct io_pgtable_ops *ops)
71 {
72 	struct io_pgtable *iop;
73 
74 	if (!ops)
75 		return;
76 
77 	iop = container_of(ops, struct io_pgtable, ops);
78 	io_pgtable_tlb_flush_all(iop);
79 	io_pgtable_init_table[iop->fmt]->free(iop);
80 }
81 EXPORT_SYMBOL_GPL(free_io_pgtable_ops);
82