2 * Copyright (C) 2012 ARM Ltd.
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.
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.
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/>.
19 #include <asm/cputype.h>
21 #define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */
22 #define USER_ASID_BIT 48
23 #define USER_ASID_FLAG (UL(1) << USER_ASID_BIT)
24 #define TTBR_ASID_MASK (UL(0xffff) << 48)
26 #define BP_HARDEN_EL2_SLOTS 4
37 * This macro is only used by the TLBI code, which cannot race with an
38 * ASID change and therefore doesn't need to reload the counter using
41 #define ASID(mm) ((mm)->context.id.counter & 0xffff)
43 static inline bool arm64_kernel_unmapped_at_el0(void)
45 return IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0
) &&
46 cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0
);
49 static inline bool arm64_kernel_use_ng_mappings(void)
53 /* What's a kpti? Use global mappings if we don't know. */
54 if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0
))
58 * Note: this function is called before the CPU capabilities have
59 * been configured, so our early mappings will be global. If we
60 * later determine that kpti is required, then
61 * kpti_install_ng_mappings() will make them non-global.
63 if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE
))
64 return arm64_kernel_unmapped_at_el0();
67 * KASLR is enabled so we're going to be enabling kpti on non-broken
68 * CPUs regardless of their susceptibility to Meltdown. Rather
69 * than force everybody to go through the G -> nG dance later on,
70 * just put down non-global mappings from the beginning.
72 if (!IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456
)) {
75 } else if (!static_branch_likely(&arm64_const_caps_ready
)) {
76 extern const struct midr_range cavium_erratum_27456_cpus
[];
78 tx1_bug
= is_midr_in_range_list(read_cpuid_id(),
79 cavium_erratum_27456_cpus
);
82 tx1_bug
= __cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456
);
85 return !tx1_bug
&& kaslr_offset() > 0;
88 typedef void (*bp_hardening_cb_t
)(void);
90 struct bp_hardening_data
{
95 #if (defined(CONFIG_HARDEN_BRANCH_PREDICTOR) || \
96 defined(CONFIG_HARDEN_EL2_VECTORS))
97 extern char __bp_harden_hyp_vecs_start
[], __bp_harden_hyp_vecs_end
[];
98 extern atomic_t arm64_el2_vector_last_slot
;
99 #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR || CONFIG_HARDEN_EL2_VECTORS */
101 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
102 DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data
, bp_hardening_data
);
104 static inline struct bp_hardening_data
*arm64_get_bp_hardening_data(void)
106 return this_cpu_ptr(&bp_hardening_data
);
109 static inline void arm64_apply_bp_hardening(void)
111 struct bp_hardening_data
*d
;
113 if (!cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR
))
116 d
= arm64_get_bp_hardening_data();
121 static inline struct bp_hardening_data
*arm64_get_bp_hardening_data(void)
126 static inline void arm64_apply_bp_hardening(void) { }
127 #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */
129 extern void paging_init(void);
130 extern void bootmem_init(void);
131 extern void __iomem
*early_io_map(phys_addr_t phys
, unsigned long virt
);
132 extern void init_mem_pgprot(void);
133 extern void create_pgd_mapping(struct mm_struct
*mm
, phys_addr_t phys
,
134 unsigned long virt
, phys_addr_t size
,
135 pgprot_t prot
, bool page_mappings_only
);
136 extern void *fixmap_remap_fdt(phys_addr_t dt_phys
);
137 extern void mark_linear_text_alias_ro(void);
139 #define INIT_MM_CONTEXT(name) \
142 #endif /* !__ASSEMBLY__ */