xref: /openbmc/linux/drivers/iommu/io-pgtable.c (revision e1d3c0fd)
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 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
28 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
29 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
30 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
31 
32 static const struct io_pgtable_init_fns *
33 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] =
34 {
35 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
36 	[ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
37 	[ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
38 	[ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
39 	[ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
40 #endif
41 };
42 
43 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
44 					    struct io_pgtable_cfg *cfg,
45 					    void *cookie)
46 {
47 	struct io_pgtable *iop;
48 	const struct io_pgtable_init_fns *fns;
49 
50 	if (fmt >= IO_PGTABLE_NUM_FMTS)
51 		return NULL;
52 
53 	fns = io_pgtable_init_table[fmt];
54 	if (!fns)
55 		return NULL;
56 
57 	iop = fns->alloc(cfg, cookie);
58 	if (!iop)
59 		return NULL;
60 
61 	iop->fmt	= fmt;
62 	iop->cookie	= cookie;
63 	iop->cfg	= *cfg;
64 
65 	return &iop->ops;
66 }
67 
68 /*
69  * It is the IOMMU driver's responsibility to ensure that the page table
70  * is no longer accessible to the walker by this point.
71  */
72 void free_io_pgtable_ops(struct io_pgtable_ops *ops)
73 {
74 	struct io_pgtable *iop;
75 
76 	if (!ops)
77 		return;
78 
79 	iop = container_of(ops, struct io_pgtable, ops);
80 	iop->cfg.tlb->tlb_flush_all(iop->cookie);
81 	io_pgtable_init_table[iop->fmt]->free(iop);
82 }
83