u-boot/arch/arm/cpu/armv7m/mpu.c
Lokesh Vutla f2ef204312 arm: v7R: Add support for MPU
The Memory Protection Unit(MPU) allows to partition memory into regions
and set individual protection attributes for each region. In absence
of MPU a default map[1] will take effect. Add support for configuring
MPU on Cortex-R, by reusing the existing support for Cortex-M processor.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0460d/I1002400.html

Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2018-05-07 15:53:29 -04:00

44 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
*/
#include <linux/bitops.h>
#include <asm/armv7m.h>
#include <asm/armv7_mpu.h>
#include <asm/io.h>
#define V7M_MPU_CTRL_ENABLE BIT(0)
#define V7M_MPU_CTRL_DISABLE (0 << 0)
#define V7M_MPU_CTRL_HFNMIENA BIT(1)
#define V7M_MPU_CTRL_PRIVDEFENA BIT(2)
#define VALID_REGION BIT(4)
void disable_mpu(void)
{
writel(0, &V7M_MPU->ctrl);
}
void enable_mpu(void)
{
writel(V7M_MPU_CTRL_ENABLE | V7M_MPU_CTRL_PRIVDEFENA, &V7M_MPU->ctrl);
/* Make sure new mpu config is effective for next memory access */
dsb();
isb(); /* Make sure instruction stream sees it */
}
void mpu_config(struct mpu_region_config *reg_config)
{
uint32_t attr;
attr = get_attr_encoding(reg_config->mr_attr);
writel(reg_config->start_addr | VALID_REGION | reg_config->region_no,
&V7M_MPU->rbar);
writel(reg_config->xn << XN_SHIFT | reg_config->ap << AP_SHIFT | attr
| reg_config->reg_size << REGION_SIZE_SHIFT | ENABLE_REGION
, &V7M_MPU->rasr);
}