1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_ASM_UACCESS_H
3 #define __ASM_ASM_UACCESS_H
5 #include <asm/alternative-macros.h>
6 #include <asm/asm-extable.h>
7 #include <asm/assembler.h>
8 #include <asm/kernel-pgtable.h>
10 #include <asm/sysreg.h>
13 * User access enabling/disabling macros.
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
22 add \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET
23 msr ttbr1_el1, \tmp1 // set reserved ASID
27 .macro __uaccess_ttbr0_enable, tmp1, tmp2
28 get_current_task \tmp1
29 ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
31 extr \tmp2, \tmp2, \tmp1, #48
33 msr ttbr1_el1, \tmp2 // set the active ASID
35 msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
39 .macro uaccess_ttbr0_disable, tmp1, tmp2
40 alternative_if_not ARM64_HAS_PAN
41 save_and_disable_irq \tmp2 // avoid preemption
42 __uaccess_ttbr0_disable \tmp1
44 alternative_else_nop_endif
47 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
48 alternative_if_not ARM64_HAS_PAN
49 save_and_disable_irq \tmp3 // avoid preemption
50 __uaccess_ttbr0_enable \tmp1, \tmp2
52 alternative_else_nop_endif
55 .macro uaccess_ttbr0_disable, tmp1, tmp2
58 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
62 #define USER(l, x...) \
67 * Generate the assembly for LDTR/STTR with exception table entries.
68 * This is complicated as there is no post-increment or pair versions of the
69 * unprivileged instructions, and USER() only works for single instructions.
71 .macro user_ldp l, reg1, reg2, addr, post_inc
72 8888: ldtr \reg1, [\addr];
73 8889: ldtr \reg2, [\addr, #8];
74 add \addr, \addr, \post_inc;
76 _asm_extable 8888b,\l;
77 _asm_extable 8889b,\l;
80 .macro user_stp l, reg1, reg2, addr, post_inc
81 8888: sttr \reg1, [\addr];
82 8889: sttr \reg2, [\addr, #8];
83 add \addr, \addr, \post_inc;
85 _asm_extable 8888b,\l;
86 _asm_extable 8889b,\l;
89 .macro user_ldst l, inst, reg, addr, post_inc
90 8888: \inst \reg, [\addr];
91 add \addr, \addr, \post_inc;
93 _asm_extable 8888b,\l;