arch/arm64/include/asm/mmu.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2012 ARM Ltd.
 */
#ifndef __ASM_MMU_H
#define __ASM_MMU_H

#include <asm/cputype.h>

#define MMCF_AARCH32	0x1	/* mm context flag for AArch32 executables */
#define USER_ASID_BIT	48
#define USER_ASID_FLAG	(UL(1) << USER_ASID_BIT)
#define TTBR_ASID_MASK	(UL(0xffff) << 48)

#define BP_HARDEN_EL2_SLOTS 4
#define __BP_HARDEN_HYP_VECS_SZ (BP_HARDEN_EL2_SLOTS * SZ_2K)

#ifndef __ASSEMBLY__

#include <linux/refcount.h>

typedef struct {
	atomic64_t	id;
#ifdef CONFIG_COMPAT
	void		*sigpage;
#endif
	refcount_t	pinned;
	void		*vdso;
	unsigned long	flags;
} mm_context_t;

/*
 * This macro is only used by the TLBI and low-level switch_mm() code,
 * neither of which can race with an ASID change. We therefore don't
 * need to reload the counter using atomic64_read().
 */
#define ASID(mm)	((mm)->context.id.counter & 0xffff)

static inline bool arm64_kernel_unmapped_at_el0(void)
{
	return cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0);
}

typedef void (*bp_hardening_cb_t)(void);

struct bp_hardening_data {
	int			hyp_vectors_slot;
	bp_hardening_cb_t	fn;
};

DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);

static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void)
{
	return this_cpu_ptr(&bp_hardening_data);
}

static inline void arm64_apply_bp_hardening(void)
{
	struct bp_hardening_data *d;

	if (!cpus_have_const_cap(ARM64_SPECTRE_V2))
		return;

	d = arm64_get_bp_hardening_data();
	if (d->fn)
		d->fn();
}

extern void arm64_memblock_init(void);
extern void paging_init(void);
extern void bootmem_init(void);
extern void __iomem *early_io_map(phys_addr_t phys, unsigned long virt);
extern void init_mem_pgprot(void);
extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
			       unsigned long virt, phys_addr_t size,
			       pgprot_t prot, bool page_mappings_only);
extern void *fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot);
extern void mark_linear_text_alias_ro(void);
extern bool kaslr_requires_kpti(void);

#define INIT_MM_CONTEXT(name)	\
	.pgd = init_pg_dir,

#endif	/* !__ASSEMBLY__ */
#endif