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/asm-extable.h>
7#include <asm/assembler.h>
8#include <asm/kernel-pgtable.h>
9#include <asm/mmu.h>
10#include <asm/sysreg.h>
11
12/*
13 * User access enabling/disabling macros.
14 */
15#ifdef CONFIG_ARM64_SW_TTBR0_PAN
16	.macro	__uaccess_ttbr0_disable, tmp1
17	mrs	\tmp1, ttbr1_el1			// swapper_pg_dir
18	bic	\tmp1, \tmp1, #TTBR_ASID_MASK
19	sub	\tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET	// reserved_pg_dir
20	msr	ttbr0_el1, \tmp1			// set reserved TTBR0_EL1
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	msr	ttbr0_el1, \tmp1		// set the non-PAN TTBR0_EL1
34	isb
35	.endm
36
37	.macro	uaccess_ttbr0_disable, tmp1, tmp2
38alternative_if_not ARM64_HAS_PAN
39	save_and_disable_irq \tmp2		// avoid preemption
40	__uaccess_ttbr0_disable \tmp1
41	restore_irq \tmp2
42alternative_else_nop_endif
43	.endm
44
45	.macro	uaccess_ttbr0_enable, tmp1, tmp2, tmp3
46alternative_if_not ARM64_HAS_PAN
47	save_and_disable_irq \tmp3		// avoid preemption
48	__uaccess_ttbr0_enable \tmp1, \tmp2
49	restore_irq \tmp3
50alternative_else_nop_endif
51	.endm
52#else
53	.macro	uaccess_ttbr0_disable, tmp1, tmp2
54	.endm
55
56	.macro	uaccess_ttbr0_enable, tmp1, tmp2, tmp3
57	.endm
58#endif
59
60#define USER(l, x...)				\
619999:	x;					\
62	_asm_extable_uaccess	9999b, l
63
64/*
65 * Generate the assembly for LDTR/STTR with exception table entries.
66 * This is complicated as there is no post-increment or pair versions of the
67 * unprivileged instructions, and USER() only works for single instructions.
68 */
69	.macro user_ldp l, reg1, reg2, addr, post_inc
708888:		ldtr	\reg1, [\addr];
718889:		ldtr	\reg2, [\addr, #8];
72		add	\addr, \addr, \post_inc;
73
74		_asm_extable_uaccess	8888b, \l;
75		_asm_extable_uaccess	8889b, \l;
76	.endm
77
78	.macro user_stp l, reg1, reg2, addr, post_inc
798888:		sttr	\reg1, [\addr];
808889:		sttr	\reg2, [\addr, #8];
81		add	\addr, \addr, \post_inc;
82
83		_asm_extable_uaccess	8888b,\l;
84		_asm_extable_uaccess	8889b,\l;
85	.endm
86
87	.macro user_ldst l, inst, reg, addr, post_inc
888888:		\inst		\reg, [\addr];
89		add		\addr, \addr, \post_inc;
90
91		_asm_extable_uaccess	8888b, \l;
92	.endm
93#endif
94