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, #PAGE_SIZE		// reserved_pg_dir just before swapper_pg_dir
19	msr	ttbr0_el1, \tmp1			// set reserved TTBR0_EL1
20	isb
21	add	\tmp1, \tmp1, #PAGE_SIZE
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#endif
62