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
21 add \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET
22 msr ttbr1_el1, \tmp1 // set reserved ASID
26 .macro __uaccess_ttbr0_enable, tmp1, tmp2
27 get_current_task \tmp1
28 ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
30 extr \tmp2, \tmp2, \tmp1, #48
32 msr ttbr1_el1, \tmp2 // set the active ASID
33 msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
37 .macro uaccess_ttbr0_disable, tmp1, tmp2
38 alternative_if_not ARM64_HAS_PAN
39 save_and_disable_irq \tmp2 // avoid preemption
40 __uaccess_ttbr0_disable \tmp1
42 alternative_else_nop_endif
45 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
46 alternative_if_not ARM64_HAS_PAN
47 save_and_disable_irq \tmp3 // avoid preemption
48 __uaccess_ttbr0_enable \tmp1, \tmp2
50 alternative_else_nop_endif
53 .macro uaccess_ttbr0_disable, tmp1, tmp2
56 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
60 #define USER(l, x...) \
62 _asm_extable_uaccess 9999b, l
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.
69 .macro user_ldp l, reg1, reg2, addr, post_inc
70 8888: ldtr \reg1, [\addr];
71 8889: ldtr \reg2, [\addr, #8];
72 add \addr, \addr, \post_inc;
74 _asm_extable_uaccess 8888b, \l;
75 _asm_extable_uaccess 8889b, \l;
78 .macro user_stp l, reg1, reg2, addr, post_inc
79 8888: sttr \reg1, [\addr];
80 8889: sttr \reg2, [\addr, #8];
81 add \addr, \addr, \post_inc;
83 _asm_extable_uaccess 8888b,\l;
84 _asm_extable_uaccess 8889b,\l;
87 .macro user_ldst l, inst, reg, addr, post_inc
88 8888: \inst \reg, [\addr];
89 add \addr, \addr, \post_inc;
91 _asm_extable_uaccess 8888b, \l;