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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_ASM_UACCESS_H
3#define __ASM_ASM_UACCESS_H
4
5#include <asm/alternative-macros.h>
6#include <asm/kernel-pgtable.h>
7#include <asm/mmu.h>
8#include <asm/sysreg.h>
9#include <asm/assembler.h>
10
11/*
12 * User access enabling/disabling macros.
13 */
14#ifdef CONFIG_ARM64_SW_TTBR0_PAN
15 .macro __uaccess_ttbr0_disable, tmp1
16 mrs \tmp1, ttbr1_el1 // swapper_pg_dir
17 bic \tmp1, \tmp1, #TTBR_ASID_MASK
18 sub \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET // reserved_pg_dir
19 msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1
20 isb
21 add \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET
22 msr ttbr1_el1, \tmp1 // set reserved ASID
23 isb
24 .endm
25
26 .macro __uaccess_ttbr0_enable, tmp1, tmp2
27 get_current_task \tmp1
28 ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
29 mrs \tmp2, ttbr1_el1
30 extr \tmp2, \tmp2, \tmp1, #48
31 ror \tmp2, \tmp2, #16
32 msr ttbr1_el1, \tmp2 // set the active ASID
33 isb
34 msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
35 isb
36 .endm
37
38 .macro uaccess_ttbr0_disable, tmp1, tmp2
39alternative_if_not ARM64_HAS_PAN
40 save_and_disable_irq \tmp2 // avoid preemption
41 __uaccess_ttbr0_disable \tmp1
42 restore_irq \tmp2
43alternative_else_nop_endif
44 .endm
45
46 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
47alternative_if_not ARM64_HAS_PAN
48 save_and_disable_irq \tmp3 // avoid preemption
49 __uaccess_ttbr0_enable \tmp1, \tmp2
50 restore_irq \tmp3
51alternative_else_nop_endif
52 .endm
53#else
54 .macro uaccess_ttbr0_disable, tmp1, tmp2
55 .endm
56
57 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
58 .endm
59#endif
60
61/*
62 * Generate the assembly for LDTR/STTR with exception table entries.
63 * This is complicated as there is no post-increment or pair versions of the
64 * unprivileged instructions, and USER() only works for single instructions.
65 */
66 .macro user_ldp l, reg1, reg2, addr, post_inc
678888: ldtr \reg1, [\addr];
688889: ldtr \reg2, [\addr, #8];
69 add \addr, \addr, \post_inc;
70
71 _asm_extable 8888b,\l;
72 _asm_extable 8889b,\l;
73 .endm
74
75 .macro user_stp l, reg1, reg2, addr, post_inc
768888: sttr \reg1, [\addr];
778889: sttr \reg2, [\addr, #8];
78 add \addr, \addr, \post_inc;
79
80 _asm_extable 8888b,\l;
81 _asm_extable 8889b,\l;
82 .endm
83
84 .macro user_ldst l, inst, reg, addr, post_inc
858888: \inst \reg, [\addr];
86 add \addr, \addr, \post_inc;
87
88 _asm_extable 8888b,\l;
89 .endm
90#endif