diff options
Diffstat (limited to 'arch/arm/cpu')
-rw-r--r-- | arch/arm/cpu/armv7m/Makefile | 2 | ||||
-rw-r--r-- | arch/arm/cpu/armv7m/mpu.c | 82 |
2 files changed, 83 insertions, 1 deletions
diff --git a/arch/arm/cpu/armv7m/Makefile b/arch/arm/cpu/armv7m/Makefile index 93c9085219..257fc7faf3 100644 --- a/arch/arm/cpu/armv7m/Makefile +++ b/arch/arm/cpu/armv7m/Makefile @@ -6,5 +6,5 @@ # extra-y := start.o -obj-y += cpu.o cache.o +obj-y += cpu.o cache.o mpu.o obj-$(CONFIG_SYS_ARCH_TIMER) += systick-timer.o diff --git a/arch/arm/cpu/armv7m/mpu.c b/arch/arm/cpu/armv7m/mpu.c new file mode 100644 index 0000000000..31a243b49a --- /dev/null +++ b/arch/arm/cpu/armv7m/mpu.c @@ -0,0 +1,82 @@ +/* + * (C) Copyright 2017 + * Vikas Manocha, ST Micoelectronics, vikas.manocha@st.com. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <linux/bitops.h> +#include <asm/armv7m.h> +#include <asm/armv7m_mpu.h> +#include <asm/io.h> + +#define V7M_MPU_CTRL_ENABLE (1 << 0) +#define V7M_MPU_CTRL_DISABLE (0 << 0) +#define V7M_MPU_CTRL_HFNMIENA (1 << 1) +#define VALID_REGION (1 << 4) + +#define ENABLE_REGION (1 << 0) + +#define AP_SHIFT 24 +#define XN_SHIFT 28 +#define TEX_SHIFT 19 +#define S_SHIFT 18 +#define C_SHIFT 17 +#define B_SHIFT 16 +#define REGION_SIZE_SHIFT 1 + +#define CACHEABLE (1 << C_SHIFT) +#define BUFFERABLE (1 << B_SHIFT) +#define SHAREABLE (1 << S_SHIFT) + +void disable_mpu(void) +{ + writel(0, &V7M_MPU->ctrl); +} + +void enable_mpu(void) +{ + writel(V7M_MPU_CTRL_ENABLE | V7M_MPU_CTRL_HFNMIENA, &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; + + switch (reg_config->mr_attr) { + case STRONG_ORDER: + attr = SHAREABLE; + break; + case SHARED_WRITE_BUFFERED: + attr = BUFFERABLE; + break; + case O_I_WT_NO_WR_ALLOC: + attr = CACHEABLE; + break; + case O_I_WB_NO_WR_ALLOC: + attr = CACHEABLE | BUFFERABLE; + break; + case O_I_NON_CACHEABLE: + attr = 1 << TEX_SHIFT; + break; + case O_I_WB_RD_WR_ALLOC: + attr = (1 << TEX_SHIFT) | CACHEABLE | BUFFERABLE; + break; + case DEVICE_NON_SHARED: + attr = (2 << TEX_SHIFT) | BUFFERABLE; + default: + attr = 0; /* strongly ordered */ + break; + }; + + 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); +} |