linux/drivers/iommu/io-pgtable.c
Will Deacon e1d3c0fd70 iommu: add ARM LPAE page table allocator
A number of IOMMUs found in ARM SoCs can walk architecture-compatible
page tables.

This patch adds a generic allocator for Stage-1 and Stage-2 v7/v8
long-descriptor page tables. 4k, 16k and 64k pages are supported, with
up to 4-levels of walk to cover a 48-bit address space.

Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-01-19 14:46:44 +00:00

83 lines
2.2 KiB
C

/*
* Generic page table allocator for IOMMUs.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright (C) 2014 ARM Limited
*
* Author: Will Deacon <will.deacon@arm.com>
*/
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include "io-pgtable.h"
extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
static const struct io_pgtable_init_fns *
io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] =
{
#ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
[ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
[ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
[ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
[ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
#endif
};
struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
struct io_pgtable_cfg *cfg,
void *cookie)
{
struct io_pgtable *iop;
const struct io_pgtable_init_fns *fns;
if (fmt >= IO_PGTABLE_NUM_FMTS)
return NULL;
fns = io_pgtable_init_table[fmt];
if (!fns)
return NULL;
iop = fns->alloc(cfg, cookie);
if (!iop)
return NULL;
iop->fmt = fmt;
iop->cookie = cookie;
iop->cfg = *cfg;
return &iop->ops;
}
/*
* It is the IOMMU driver's responsibility to ensure that the page table
* is no longer accessible to the walker by this point.
*/
void free_io_pgtable_ops(struct io_pgtable_ops *ops)
{
struct io_pgtable *iop;
if (!ops)
return;
iop = container_of(ops, struct io_pgtable, ops);
iop->cfg.tlb->tlb_flush_all(iop->cookie);
io_pgtable_init_table[iop->fmt]->free(iop);
}