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author | 2023-10-10 14:33:42 +0000 | |
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committer | 2023-10-10 14:33:42 +0000 | |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/arch/arm/cpu/armv7/mpu_v7r.c | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/arch/arm/cpu/armv7/mpu_v7r.c')
-rw-r--r-- | roms/u-boot/arch/arm/cpu/armv7/mpu_v7r.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/roms/u-boot/arch/arm/cpu/armv7/mpu_v7r.c b/roms/u-boot/arch/arm/cpu/armv7/mpu_v7r.c new file mode 100644 index 000000000..57ab640e2 --- /dev/null +++ b/roms/u-boot/arch/arm/cpu/armv7/mpu_v7r.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Cortex-R Memory Protection Unit specific code + * + * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/ + * Lokesh Vutla <lokeshvutla@ti.com> + */ + +#include <common.h> +#include <command.h> +#include <cpu_func.h> +#include <asm/armv7.h> +#include <asm/system.h> +#include <asm/barriers.h> +#include <linux/bitops.h> +#include <linux/compiler.h> + +#include <asm/armv7_mpu.h> + +/* MPU Type register definitions */ +#define MPUIR_S_SHIFT 0 +#define MPUIR_S_MASK BIT(MPUIR_S_SHIFT) +#define MPUIR_DREGION_SHIFT 8 +#define MPUIR_DREGION_MASK (0xff << 8) + +/** + * Note: + * 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. make sure to run this code + * from a region which has execution permissions by default. + * [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0460d/I1002400.html + */ + +void disable_mpu(void) +{ + u32 reg; + + reg = get_cr(); + reg &= ~CR_M; + dsb(); + set_cr(reg); + isb(); +} + +void enable_mpu(void) +{ + u32 reg; + + reg = get_cr(); + reg |= CR_M; + dsb(); + set_cr(reg); + isb(); +} + +int mpu_enabled(void) +{ + return get_cr() & CR_M; +} + +void mpu_config(struct mpu_region_config *rgn) +{ + u32 attr, val; + + attr = get_attr_encoding(rgn->mr_attr); + + /* MPU Region Number Register */ + asm volatile ("mcr p15, 0, %0, c6, c2, 0" : : "r" (rgn->region_no)); + + /* MPU Region Base Address Register */ + asm volatile ("mcr p15, 0, %0, c6, c1, 0" : : "r" (rgn->start_addr)); + + /* MPU Region Size and Enable Register */ + if (rgn->reg_size) + val = (rgn->reg_size << REGION_SIZE_SHIFT) | ENABLE_REGION; + else + val = DISABLE_REGION; + asm volatile ("mcr p15, 0, %0, c6, c1, 2" : : "r" (val)); + + /* MPU Region Access Control Register */ + val = rgn->xn << XN_SHIFT | rgn->ap << AP_SHIFT | attr; + asm volatile ("mcr p15, 0, %0, c6, c1, 4" : : "r" (val)); +} + +void setup_mpu_regions(struct mpu_region_config *rgns, u32 num_rgns) +{ + u32 num, i; + + asm volatile ("mrc p15, 0, %0, c0, c0, 4" : "=r" (num)); + num = (num & MPUIR_DREGION_MASK) >> MPUIR_DREGION_SHIFT; + /* Regions to be configured cannot be greater than available regions */ + if (num < num_rgns) + num_rgns = num; + /** + * Assuming dcache might not be enabled at this point, disabling + * and invalidating only icache. + */ + icache_disable(); + invalidate_icache_all(); + + disable_mpu(); + + for (i = 0; i < num_rgns; i++) + mpu_config(&rgns[i]); + + enable_mpu(); + + icache_enable(); +} + +void enable_caches(void) +{ + /* + * setup_mpu_regions() might have enabled Icache. So add a check + * before enabling Icache + */ + if (!icache_status()) + icache_enable(); + dcache_enable(); +} |