arch/arm/include/asm/mpu.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ARM_MPU_H
#define __ARM_MPU_H

/* MPUIR layout */
#define MPUIR_nU		1
#define MPUIR_DREGION		8
#define MPUIR_IREGION		16
#define MPUIR_DREGION_SZMASK	(0xFF << MPUIR_DREGION)
#define MPUIR_IREGION_SZMASK	(0xFF << MPUIR_IREGION)

/* ID_MMFR0 data relevant to MPU */
#define MMFR0_PMSA		(0xF << 4)
#define MMFR0_PMSAv7		(3 << 4)

/* MPU D/I Size Register fields */
#define MPU_RSR_SZ		1
#define MPU_RSR_EN		0
#define MPU_RSR_SD		8

/* Number of subregions (SD) */
#define MPU_NR_SUBREGS		8
#define MPU_MIN_SUBREG_SIZE	256

/* The D/I RSR value for an enabled region spanning the whole of memory */
#define MPU_RSR_ALL_MEM		63

/* Individual bits in the DR/IR ACR */
#define MPU_ACR_XN		(1 << 12)
#define MPU_ACR_SHARED		(1 << 2)

/* C, B and TEX[2:0] bits only have semantic meanings when grouped */
#define MPU_RGN_CACHEABLE	0xB
#define MPU_RGN_SHARED_CACHEABLE (MPU_RGN_CACHEABLE | MPU_ACR_SHARED)
#define MPU_RGN_STRONGLY_ORDERED 0

/* Main region should only be shared for SMP */
#ifdef CONFIG_SMP
#define MPU_RGN_NORMAL		(MPU_RGN_CACHEABLE | MPU_ACR_SHARED)
#else
#define MPU_RGN_NORMAL		MPU_RGN_CACHEABLE
#endif

/* Access permission bits of ACR (only define those that we use)*/
#define MPU_AP_PL1RO_PL0NA	(0x5 << 8)
#define MPU_AP_PL1RW_PL0RW	(0x3 << 8)
#define MPU_AP_PL1RW_PL0R0	(0x2 << 8)
#define MPU_AP_PL1RW_PL0NA	(0x1 << 8)

/* For minimal static MPU region configurations */
#define MPU_PROBE_REGION	0
#define MPU_BG_REGION		1
#define MPU_RAM_REGION		2
#define MPU_ROM_REGION		3

/* Maximum number of regions Linux is interested in */
#define MPU_MAX_REGIONS		16

#define MPU_DATA_SIDE		0
#define MPU_INSTR_SIDE		1

#ifndef __ASSEMBLY__

struct mpu_rgn {
	/* Assume same attributes for d/i-side  */
	u32 drbar;
	u32 drsr;
	u32 dracr;
};

struct mpu_rgn_info {
	unsigned int used;
	struct mpu_rgn rgns[MPU_MAX_REGIONS];
};
extern struct mpu_rgn_info mpu_rgn_info;

#ifdef CONFIG_ARM_MPU

extern void __init adjust_lowmem_bounds_mpu(void);
extern void __init mpu_setup(void);

#else

static inline void adjust_lowmem_bounds_mpu(void) {}
static inline void mpu_setup(void) {}

#endif /* !CONFIG_ARM_MPU */

#endif /* __ASSEMBLY__ */

#endif