xref: /OK3568_Linux_fs/kernel/arch/arm64/include/asm/asm-uaccess.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef __ASM_ASM_UACCESS_H
3*4882a593Smuzhiyun #define __ASM_ASM_UACCESS_H
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #include <asm/alternative-macros.h>
6*4882a593Smuzhiyun #include <asm/kernel-pgtable.h>
7*4882a593Smuzhiyun #include <asm/mmu.h>
8*4882a593Smuzhiyun #include <asm/sysreg.h>
9*4882a593Smuzhiyun #include <asm/assembler.h>
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun /*
12*4882a593Smuzhiyun  * User access enabling/disabling macros.
13*4882a593Smuzhiyun  */
14*4882a593Smuzhiyun #ifdef CONFIG_ARM64_SW_TTBR0_PAN
15*4882a593Smuzhiyun 	.macro	__uaccess_ttbr0_disable, tmp1
16*4882a593Smuzhiyun 	mrs	\tmp1, ttbr1_el1			// swapper_pg_dir
17*4882a593Smuzhiyun 	bic	\tmp1, \tmp1, #TTBR_ASID_MASK
18*4882a593Smuzhiyun 	sub	\tmp1, \tmp1, #PAGE_SIZE		// reserved_pg_dir just before swapper_pg_dir
19*4882a593Smuzhiyun 	msr	ttbr0_el1, \tmp1			// set reserved TTBR0_EL1
20*4882a593Smuzhiyun 	isb
21*4882a593Smuzhiyun 	add	\tmp1, \tmp1, #PAGE_SIZE
22*4882a593Smuzhiyun 	msr	ttbr1_el1, \tmp1		// set reserved ASID
23*4882a593Smuzhiyun 	isb
24*4882a593Smuzhiyun 	.endm
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun 	.macro	__uaccess_ttbr0_enable, tmp1, tmp2
27*4882a593Smuzhiyun 	get_current_task \tmp1
28*4882a593Smuzhiyun 	ldr	\tmp1, [\tmp1, #TSK_TI_TTBR0]	// load saved TTBR0_EL1
29*4882a593Smuzhiyun 	mrs	\tmp2, ttbr1_el1
30*4882a593Smuzhiyun 	extr    \tmp2, \tmp2, \tmp1, #48
31*4882a593Smuzhiyun 	ror     \tmp2, \tmp2, #16
32*4882a593Smuzhiyun 	msr	ttbr1_el1, \tmp2		// set the active ASID
33*4882a593Smuzhiyun 	isb
34*4882a593Smuzhiyun 	msr	ttbr0_el1, \tmp1		// set the non-PAN TTBR0_EL1
35*4882a593Smuzhiyun 	isb
36*4882a593Smuzhiyun 	.endm
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun 	.macro	uaccess_ttbr0_disable, tmp1, tmp2
39*4882a593Smuzhiyun alternative_if_not ARM64_HAS_PAN
40*4882a593Smuzhiyun 	save_and_disable_irq \tmp2		// avoid preemption
41*4882a593Smuzhiyun 	__uaccess_ttbr0_disable \tmp1
42*4882a593Smuzhiyun 	restore_irq \tmp2
43*4882a593Smuzhiyun alternative_else_nop_endif
44*4882a593Smuzhiyun 	.endm
45*4882a593Smuzhiyun 
46*4882a593Smuzhiyun 	.macro	uaccess_ttbr0_enable, tmp1, tmp2, tmp3
47*4882a593Smuzhiyun alternative_if_not ARM64_HAS_PAN
48*4882a593Smuzhiyun 	save_and_disable_irq \tmp3		// avoid preemption
49*4882a593Smuzhiyun 	__uaccess_ttbr0_enable \tmp1, \tmp2
50*4882a593Smuzhiyun 	restore_irq \tmp3
51*4882a593Smuzhiyun alternative_else_nop_endif
52*4882a593Smuzhiyun 	.endm
53*4882a593Smuzhiyun #else
54*4882a593Smuzhiyun 	.macro	uaccess_ttbr0_disable, tmp1, tmp2
55*4882a593Smuzhiyun 	.endm
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun 	.macro	uaccess_ttbr0_enable, tmp1, tmp2, tmp3
58*4882a593Smuzhiyun 	.endm
59*4882a593Smuzhiyun #endif
60*4882a593Smuzhiyun 
61*4882a593Smuzhiyun /*
62*4882a593Smuzhiyun  * Generate the assembly for LDTR/STTR with exception table entries.
63*4882a593Smuzhiyun  * This is complicated as there is no post-increment or pair versions of the
64*4882a593Smuzhiyun  * unprivileged instructions, and USER() only works for single instructions.
65*4882a593Smuzhiyun  */
66*4882a593Smuzhiyun 	.macro uao_ldp l, reg1, reg2, addr, post_inc
67*4882a593Smuzhiyun 8888:		ldtr	\reg1, [\addr];
68*4882a593Smuzhiyun 8889:		ldtr	\reg2, [\addr, #8];
69*4882a593Smuzhiyun 		add	\addr, \addr, \post_inc;
70*4882a593Smuzhiyun 
71*4882a593Smuzhiyun 		_asm_extable	8888b,\l;
72*4882a593Smuzhiyun 		_asm_extable	8889b,\l;
73*4882a593Smuzhiyun 	.endm
74*4882a593Smuzhiyun 
75*4882a593Smuzhiyun 	.macro uao_stp l, reg1, reg2, addr, post_inc
76*4882a593Smuzhiyun 8888:		sttr	\reg1, [\addr];
77*4882a593Smuzhiyun 8889:		sttr	\reg2, [\addr, #8];
78*4882a593Smuzhiyun 		add	\addr, \addr, \post_inc;
79*4882a593Smuzhiyun 
80*4882a593Smuzhiyun 		_asm_extable	8888b,\l;
81*4882a593Smuzhiyun 		_asm_extable	8889b,\l;
82*4882a593Smuzhiyun 	.endm
83*4882a593Smuzhiyun 
84*4882a593Smuzhiyun 	.macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
85*4882a593Smuzhiyun 8888:		\alt_inst	\reg, [\addr];
86*4882a593Smuzhiyun 		add		\addr, \addr, \post_inc;
87*4882a593Smuzhiyun 
88*4882a593Smuzhiyun 		_asm_extable	8888b,\l;
89*4882a593Smuzhiyun 	.endm
90*4882a593Smuzhiyun #endif
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