M7350/kernel/drivers/iommu/io-pgtable.c
2024-09-09 08:57:42 +00:00

142 lines
3.5 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>
*/
#define pr_fmt(fmt) "io-pgtable: " fmt
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/iommu.h>
#include <linux/debugfs.h>
#include <linux/atomic.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
};
static struct dentry *io_pgtable_top;
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);
io_pgtable_init_table[iop->fmt]->free(iop);
}
static atomic_t pages_allocated;
void *io_pgtable_alloc_pages_exact(struct io_pgtable_cfg *cfg, void *cookie,
size_t size, gfp_t gfp_mask)
{
void *ret;
if (cfg->tlb->alloc_pages_exact)
ret = cfg->tlb->alloc_pages_exact(cookie, size, gfp_mask);
else
ret = alloc_pages_exact(size, gfp_mask);
if (likely(ret))
atomic_add(1 << get_order(size), &pages_allocated);
return ret;
}
void io_pgtable_free_pages_exact(struct io_pgtable_cfg *cfg, void *cookie,
void *virt, size_t size)
{
if (cfg->tlb->free_pages_exact)
cfg->tlb->free_pages_exact(cookie, virt, size);
else
free_pages_exact(virt, size);
atomic_sub(1 << get_order(size), &pages_allocated);
}
static int io_pgtable_init(void)
{
io_pgtable_top = debugfs_create_dir("io-pgtable", iommu_debugfs_top);
if (!io_pgtable_top)
return -ENODEV;
if (!debugfs_create_atomic_t("pages", 0600,
io_pgtable_top, &pages_allocated)) {
debugfs_remove_recursive(io_pgtable_top);
return -ENODEV;
}
return 0;
}
static void io_pgtable_exit(void)
{
debugfs_remove_recursive(io_pgtable_top);
}
module_init(io_pgtable_init);
module_exit(io_pgtable_exit);