arch/arm64/include/asm/mmu.h

   1 /*
   2  * Copyright (C) 2012 ARM Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #ifndef __ASM_MMU_H
  17 #define __ASM_MMU_H
  18
  19 #define MMCF_AARCH32    0x1     /* mm context flag for AArch32 executables */
  20 #define USER_ASID_FLAG  (UL(1) << 48)
  21 #define TTBR_ASID_MASK  (UL(0xffff) << 48)
  22
  23 #ifndef __ASSEMBLY__
  24
  25 typedef struct {
  26         atomic64_t      id;
  27         void            *vdso;
  28         unsigned long   flags;
  29 } mm_context_t;
  30
  31 /*
  32  * This macro is only used by the TLBI code, which cannot race with an
  33  * ASID change and therefore doesn't need to reload the counter using
  34  * atomic64_read.
  35  */
  36 #define ASID(mm)        ((mm)->context.id.counter & 0xffff)
  37
  38 static inline bool arm64_kernel_unmapped_at_el0(void)
  39 {
  40         return IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0) &&
  41                cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0);
  42 }
  43
  44 typedef void (*bp_hardening_cb_t)(void);
  45
  46 struct bp_hardening_data {
  47         int                     hyp_vectors_slot;
  48         bp_hardening_cb_t       fn;
  49 };
  50
  51 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
  52 extern char __bp_harden_hyp_vecs_start[], __bp_harden_hyp_vecs_end[];
  53
  54 DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
  55
  56 static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void)
  57 {
  58         return this_cpu_ptr(&bp_hardening_data);
  59 }
  60
  61 static inline void arm64_apply_bp_hardening(void)
  62 {
  63         struct bp_hardening_data *d;
  64
  65         if (!cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR))
  66                 return;
  67
  68         d = arm64_get_bp_hardening_data();
  69         if (d->fn)
  70                 d->fn();
  71 }
  72 #else
  73 static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void)
  74 {
  75         return NULL;
  76 }
  77
  78 static inline void arm64_apply_bp_hardening(void)       { }
  79 #endif  /* CONFIG_HARDEN_BRANCH_PREDICTOR */
  80
  81 extern void paging_init(void);
  82 extern void bootmem_init(void);
  83 extern void __iomem *early_io_map(phys_addr_t phys, unsigned long virt);
  84 extern void init_mem_pgprot(void);
  85 extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
  86                                unsigned long virt, phys_addr_t size,
  87                                pgprot_t prot, bool page_mappings_only);
  88 extern void *fixmap_remap_fdt(phys_addr_t dt_phys);
  89 extern void mark_linear_text_alias_ro(void);
  90
  91 #endif  /* !__ASSEMBLY__ */
  92 #endif