[linux-2.6-block.git] / arch / arm64 / include / asm / asm-uaccess.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ASM_UACCESS_H
#define __ASM_ASM_UACCESS_H

#include <asm/alternative.h>
#include <asm/kernel-pgtable.h>
#include <asm/mmu.h>
#include <asm/sysreg.h>
#include <asm/assembler.h>

/*
 * User access enabling/disabling macros.
 */
#ifdef CONFIG_ARM64_SW_TTBR0_PAN
	.macro	__uaccess_ttbr0_disable, tmp1
	mrs	\tmp1, ttbr1_el1			// swapper_pg_dir
	bic	\tmp1, \tmp1, #TTBR_ASID_MASK
	sub	\tmp1, \tmp1, #RESERVED_TTBR0_SIZE	// reserved_ttbr0 just before swapper_pg_dir
	msr	ttbr0_el1, \tmp1			// set reserved TTBR0_EL1
	isb
	add	\tmp1, \tmp1, #RESERVED_TTBR0_SIZE
	msr	ttbr1_el1, \tmp1		// set reserved ASID
	isb
	.endm

	.macro	__uaccess_ttbr0_enable, tmp1, tmp2
	get_current_task \tmp1
	ldr	\tmp1, [\tmp1, #TSK_TI_TTBR0]	// load saved TTBR0_EL1
	mrs	\tmp2, ttbr1_el1
	extr    \tmp2, \tmp2, \tmp1, #48
	ror     \tmp2, \tmp2, #16
	msr	ttbr1_el1, \tmp2		// set the active ASID
	isb
	msr	ttbr0_el1, \tmp1		// set the non-PAN TTBR0_EL1
	isb
	.endm

	.macro	uaccess_ttbr0_disable, tmp1, tmp2
alternative_if_not ARM64_HAS_PAN
	save_and_disable_irq \tmp2		// avoid preemption
	__uaccess_ttbr0_disable \tmp1
	restore_irq \tmp2
alternative_else_nop_endif
	.endm

	.macro	uaccess_ttbr0_enable, tmp1, tmp2, tmp3
alternative_if_not ARM64_HAS_PAN
	save_and_disable_irq \tmp3		// avoid preemption
	__uaccess_ttbr0_enable \tmp1, \tmp2
	restore_irq \tmp3
alternative_else_nop_endif
	.endm
#else
	.macro	uaccess_ttbr0_disable, tmp1, tmp2
	.endm

	.macro	uaccess_ttbr0_enable, tmp1, tmp2, tmp3
	.endm
#endif

/*
 * Generate the assembly for UAO alternatives with exception table entries.
 * This is complicated as there is no post-increment or pair versions of the
 * unprivileged instructions, and USER() only works for single instructions.
 */
#ifdef CONFIG_ARM64_UAO
	.macro uao_ldp l, reg1, reg2, addr, post_inc
		alternative_if_not ARM64_HAS_UAO
8888:			ldp	\reg1, \reg2, [\addr], \post_inc;
8889:			nop;
			nop;
		alternative_else
			ldtr	\reg1, [\addr];
			ldtr	\reg2, [\addr, #8];
			add	\addr, \addr, \post_inc;
		alternative_endif

		_asm_extable	8888b,\l;
		_asm_extable	8889b,\l;
	.endm

	.macro uao_stp l, reg1, reg2, addr, post_inc
		alternative_if_not ARM64_HAS_UAO
8888:			stp	\reg1, \reg2, [\addr], \post_inc;
8889:			nop;
			nop;
		alternative_else
			sttr	\reg1, [\addr];
			sttr	\reg2, [\addr, #8];
			add	\addr, \addr, \post_inc;
		alternative_endif

		_asm_extable	8888b,\l;
		_asm_extable	8889b,\l;
	.endm

	.macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
		alternative_if_not ARM64_HAS_UAO
8888:			\inst	\reg, [\addr], \post_inc;
			nop;
		alternative_else
			\alt_inst	\reg, [\addr];
			add		\addr, \addr, \post_inc;
		alternative_endif

		_asm_extable	8888b,\l;
	.endm
#else
	.macro uao_ldp l, reg1, reg2, addr, post_inc
		USER(\l, ldp \reg1, \reg2, [\addr], \post_inc)
	.endm
	.macro uao_stp l, reg1, reg2, addr, post_inc
		USER(\l, stp \reg1, \reg2, [\addr], \post_inc)
	.endm
	.macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
		USER(\l, \inst \reg, [\addr], \post_inc)
	.endm
#endif

#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
b4b8664d AV	2	#ifndef __ASM_ASM_UACCESS_H
	3	#define __ASM_ASM_UACCESS_H
	4
	5	#include <asm/alternative.h>
	6	#include <asm/kernel-pgtable.h>
b519538d	7	#include <asm/mmu.h>
b4b8664d AV	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
9dfe4828	16	mrs \tmp1, ttbr1_el1 // swapper_pg_dir
6b88a32c	17	bic \tmp1, \tmp1, #TTBR_ASID_MASK
9dfe4828 SC	18	sub \tmp1, \tmp1, #RESERVED_TTBR0_SIZE // reserved_ttbr0 just before swapper_pg_dir
9dfe4828 SC	19	msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1
b4b8664d	20	isb
9dfe4828	21	add \tmp1, \tmp1, #RESERVED_TTBR0_SIZE
27a921e7 WD	22	msr ttbr1_el1, \tmp1 // set reserved ASID
27a921e7 WD	23	isb
b4b8664d AV	24	.endm
b4b8664d AV	25
27a921e7	26	.macro __uaccess_ttbr0_enable, tmp1, tmp2
4caf8758	27	get_current_task \tmp1
b4b8664d	28	ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
27a921e7 WD	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
b4b8664d AV	34	msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
	35	isb
	36	.endm
	37
6b88a32c	38	.macro uaccess_ttbr0_disable, tmp1, tmp2
b4b8664d	39	alternative_if_not ARM64_HAS_PAN
6b88a32c	40	save_and_disable_irq \tmp2 // avoid preemption
b4b8664d	41	__uaccess_ttbr0_disable \tmp1
6b88a32c	42	restore_irq \tmp2
b4b8664d AV	43	alternative_else_nop_endif
	44	.endm
	45
27a921e7	46	.macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
b4b8664d	47	alternative_if_not ARM64_HAS_PAN
27a921e7 WD	48	save_and_disable_irq \tmp3 // avoid preemption
	49	__uaccess_ttbr0_enable \tmp1, \tmp2
	50	restore_irq \tmp3
b4b8664d AV	51	alternative_else_nop_endif
	52	.endm
	53	#else
6b88a32c	54	.macro uaccess_ttbr0_disable, tmp1, tmp2
b4b8664d AV	55	.endm
b4b8664d AV	56
27a921e7	57	.macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
b4b8664d AV	58	.endm
	59	#endif
	60
e2a2190a MR	61	/*
	62	* Generate the assembly for UAO alternatives 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	#ifdef CONFIG_ARM64_UAO
	67	.macro uao_ldp l, reg1, reg2, addr, post_inc
	68	alternative_if_not ARM64_HAS_UAO
	69	8888: ldp \reg1, \reg2, [\addr], \post_inc;
	70	8889: nop;
	71	nop;
	72	alternative_else
	73	ldtr \reg1, [\addr];
	74	ldtr \reg2, [\addr, #8];
	75	add \addr, \addr, \post_inc;
	76	alternative_endif
	77
	78	_asm_extable 8888b,\l;
	79	_asm_extable 8889b,\l;
	80	.endm
	81
	82	.macro uao_stp l, reg1, reg2, addr, post_inc
	83	alternative_if_not ARM64_HAS_UAO
	84	8888: stp \reg1, \reg2, [\addr], \post_inc;
	85	8889: nop;
	86	nop;
	87	alternative_else
	88	sttr \reg1, [\addr];
	89	sttr \reg2, [\addr, #8];
	90	add \addr, \addr, \post_inc;
	91	alternative_endif
	92
	93	_asm_extable 8888b,\l;
	94	_asm_extable 8889b,\l;
	95	.endm
	96
	97	.macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
	98	alternative_if_not ARM64_HAS_UAO
	99	8888: \inst \reg, [\addr], \post_inc;
	100	nop;
	101	alternative_else
	102	\alt_inst \reg, [\addr];
	103	add \addr, \addr, \post_inc;
	104	alternative_endif
	105
	106	_asm_extable 8888b,\l;
	107	.endm
	108	#else
	109	.macro uao_ldp l, reg1, reg2, addr, post_inc
	110	USER(\l, ldp \reg1, \reg2, [\addr], \post_inc)
	111	.endm
	112	.macro uao_stp l, reg1, reg2, addr, post_inc
	113	USER(\l, stp \reg1, \reg2, [\addr], \post_inc)
	114	.endm
	115	.macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
	116	USER(\l, \inst \reg, [\addr], \post_inc)
	117	.endm
	118	#endif
	119
b4b8664d	120	#endif