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/kernel.h>
23 #include <linux/types.h>
24
25 #include "io-pgtable.h"
26
27 static const struct io_pgtable_init_fns *
28 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] =
29 {
30 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
31 [ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
32 [ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
33 [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
34 [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
35 #endif
36 };
37
alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,struct io_pgtable_cfg * cfg,void * cookie)38 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
39 struct io_pgtable_cfg *cfg,
40 void *cookie)
41 {
42 struct io_pgtable *iop;
43 const struct io_pgtable_init_fns *fns;
44
45 if (fmt >= IO_PGTABLE_NUM_FMTS)
46 return NULL;
47
48 fns = io_pgtable_init_table[fmt];
49 if (!fns)
50 return NULL;
51
52 iop = fns->alloc(cfg, cookie);
53 if (!iop)
54 return NULL;
55
56 iop->fmt = fmt;
57 iop->cookie = cookie;
58 iop->cfg = *cfg;
59
60 return &iop->ops;
61 }
62
63 /*
64 * It is the IOMMU driver's responsibility to ensure that the page table
65 * is no longer accessible to the walker by this point.
66 */
free_io_pgtable_ops(struct io_pgtable_ops * ops)67 void free_io_pgtable_ops(struct io_pgtable_ops *ops)
68 {
69 struct io_pgtable *iop;
70
71 if (!ops)
72 return;
73
74 iop = container_of(ops, struct io_pgtable, ops);
75 iop->cfg.tlb->tlb_flush_all(iop->cookie);
76 io_pgtable_init_table[iop->fmt]->free(iop);
77 }
78