linux-imx

/*

 * CPU-agnostic ARM page table allocator.

 *

 * ARMv7 Short-descriptor format, supporting

 * - Basic memory attributes

 * - Simplified access permissions (AP[2:1] model)

 * - Backwards-compatible TEX remap

 * - Large pages/supersections (if indicated by the caller)

 *

 * Not supporting:

 * - Legacy access permissions (AP[2:0] model)

 *

 * Almost certainly never supporting:

 * - PXN

 * - Domains

 *

 * 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) 2014-2015 ARM Limited

 * Copyright (c) 2014-2015 MediaTek Inc.

 */

​

#define pr_fmt(fmt) "arm-v7s io-pgtable: " fmt

​

#include <linux/atomic.h>

#include <linux/dma-mapping.h>

#include <linux/gfp.h>

#include <linux/io-pgtable.h>

#include <linux/iommu.h>

#include <linux/kernel.h>

#include <linux/kmemleak.h>

#include <linux/sizes.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/types.h>

​

#include <asm/barrier.h>

​

/* Struct accessors */

#define io_pgtable_to_data(x)                       \

    container_of((x), struct arm_v7s_io_pgtable, iop)

​

#define io_pgtable_ops_to_data(x)                   \

    io_pgtable_to_data(io_pgtable_ops_to_pgtable(x))

​

/*

 * We have 32 bits total; 12 bits resolved at level 1, 8 bits at level 2,

 * and 12 bits in a page. With some carefully-chosen coefficients we can

 * hide the ugly inconsistencies behind these macros and at least let the

 * rest of the code pretend to be somewhat sane.

 */

#define ARM_V7S_ADDR_BITS       32

#define _ARM_V7S_LVL_BITS(lvl)      (16 - (lvl) * 4)