LXR uboot/arch/arm/cpu/armv7m/mpu.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
   4 * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
   5 */
   6
   7#include <linux/bitops.h>
   8#include <asm/armv7m.h>
   9#include <asm/armv7_mpu.h>
  10#include <asm/io.h>
  11
  12#define V7M_MPU_CTRL_ENABLE             BIT(0)
  13#define V7M_MPU_CTRL_DISABLE            (0 << 0)
  14#define V7M_MPU_CTRL_HFNMIENA           BIT(1)
  15#define V7M_MPU_CTRL_PRIVDEFENA         BIT(2)
  16#define VALID_REGION                    BIT(4)
  17
  18void disable_mpu(void)
  19{
  20        writel(0, &V7M_MPU->ctrl);
  21}
  22
  23void enable_mpu(void)
  24{
  25        writel(V7M_MPU_CTRL_ENABLE | V7M_MPU_CTRL_PRIVDEFENA, &V7M_MPU->ctrl);
  26
  27        /* Make sure new mpu config is effective for next memory access */
  28        dsb();
  29        isb();  /* Make sure instruction stream sees it */
  30}
  31
  32void mpu_config(struct mpu_region_config *reg_config)
  33{
  34        uint32_t attr;
  35
  36        attr = get_attr_encoding(reg_config->mr_attr);
  37
  38        writel(reg_config->start_addr | VALID_REGION | reg_config->region_no,
  39               &V7M_MPU->rbar);
  40
  41        writel(reg_config->xn << XN_SHIFT | reg_config->ap << AP_SHIFT | attr
  42                | reg_config->reg_size << REGION_SIZE_SHIFT | ENABLE_REGION
  43               , &V7M_MPU->rasr);
  44}
  45