linux/arch/arm64/include/asm/mmu.h
Will Deacon 6e5f092784 arm64: Remove Spectre-related CONFIG_* options
The spectre mitigations are too configurable for their own good, leading
to confusing logic trying to figure out when we should mitigate and when
we shouldn't. Although the plethora of command-line options need to stick
around for backwards compatibility, the default-on CONFIG options that
depend on EXPERT can be dropped, as the mitigations only do anything if
the system is vulnerable, a mitigation is available and the command-line
hasn't disabled it.

Remove CONFIG_HARDEN_BRANCH_PREDICTOR and CONFIG_ARM64_SSBD in favour of
enabling this code unconditionally.

Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:15 +01:00

84 lines
2.1 KiB
C

/* 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__
typedef struct {
atomic64_t id;
#ifdef CONFIG_COMPAT
void *sigpage;
#endif
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_HARDEN_BRANCH_PREDICTOR))
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