xref: /linux/arch/arm/include/asm/mpu.h (revision 9cfb541a4ad45168925078f7d1fe3a7363ba27e2)

/* 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 PMSAv7_RSR_SZ		1
#define PMSAv7_RSR_EN		0
#define PMSAv7_RSR_SD		8

/* Number of subregions (SD) */
#define PMSAv7_NR_SUBREGS	8
#define PMSAv7_MIN_SUBREG_SIZE	256

/* The D/I RSR value for an enabled region spanning the whole of memory */
#define PMSAv7_RSR_ALL_MEM	63

/* Individual bits in the DR/IR ACR */
#define PMSAv7_ACR_XN		(1 << 12)
#define PMSAv7_ACR_SHARED	(1 << 2)

/* C, B and TEX[2:0] bits only have semantic meanings when grouped */
#define PMSAv7_RGN_CACHEABLE		0xB
#define PMSAv7_RGN_SHARED_CACHEABLE	(PMSAv7_RGN_CACHEABLE | PMSAv7_ACR_SHARED)
#define PMSAv7_RGN_STRONGLY_ORDERED	0

/* Main region should only be shared for SMP */
#ifdef CONFIG_SMP
#define PMSAv7_RGN_NORMAL	(PMSAv7_RGN_CACHEABLE | PMSAv7_ACR_SHARED)
#else
#define PMSAv7_RGN_NORMAL	PMSAv7_RGN_CACHEABLE
#endif

/* Access permission bits of ACR (only define those that we use)*/
#define PMSAv7_AP_PL1RO_PL0NA	(0x5 << 8)
#define PMSAv7_AP_PL1RW_PL0RW	(0x3 << 8)
#define PMSAv7_AP_PL1RW_PL0R0	(0x2 << 8)
#define PMSAv7_AP_PL1RW_PL0NA	(0x1 << 8)

/* For minimal static MPU region configurations */
#define PMSAv7_PROBE_REGION	0
#define PMSAv7_BG_REGION	1
#define PMSAv7_RAM_REGION	2
#define PMSAv7_ROM_REGION	3

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

#define PMSAv7_DATA_SIDE	0
#define PMSAv7_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 pmsav7_adjust_lowmem_bounds(void);
extern void __init pmsav7_setup(void);
#else
static inline void pmsav7_adjust_lowmem_bounds(void) {};
static inline void pmsav7_setup(void) {};
#endif

#endif /* __ASSEMBLY__ */

#endif