GNU Linux-libre 4.14.290-gnu1
[releases.git] / arch / arm64 / include / asm / asm-uaccess.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_ASM_UACCESS_H
3 #define __ASM_ASM_UACCESS_H
4
5 #include <asm/alternative.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         add     \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir
19         msr     ttbr0_el1, \tmp1                // set reserved TTBR0_EL1
20         isb
21         sub     \tmp1, \tmp1, #SWAPPER_DIR_SIZE
22         msr     ttbr1_el1, \tmp1                // set reserved ASID
23         isb
24         .endm
25
26         .macro  __uaccess_ttbr0_enable, tmp1, tmp2
27         get_thread_info \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
39 alternative_if_not ARM64_HAS_PAN
40         save_and_disable_irq \tmp2              // avoid preemption
41         __uaccess_ttbr0_disable \tmp1
42         restore_irq \tmp2
43 alternative_else_nop_endif
44         .endm
45
46         .macro  uaccess_ttbr0_enable, tmp1, tmp2, tmp3
47 alternative_if_not ARM64_HAS_PAN
48         save_and_disable_irq \tmp3              // avoid preemption
49         __uaccess_ttbr0_enable \tmp1, \tmp2
50         restore_irq \tmp3
51 alternative_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 /*
62  * These macros are no-ops when UAO is present.
63  */
64         .macro  uaccess_disable_not_uao, tmp1, tmp2
65         uaccess_ttbr0_disable \tmp1, \tmp2
66 alternative_if ARM64_ALT_PAN_NOT_UAO
67         SET_PSTATE_PAN(1)
68 alternative_else_nop_endif
69         .endm
70
71         .macro  uaccess_enable_not_uao, tmp1, tmp2, tmp3
72         uaccess_ttbr0_enable \tmp1, \tmp2, \tmp3
73 alternative_if ARM64_ALT_PAN_NOT_UAO
74         SET_PSTATE_PAN(0)
75 alternative_else_nop_endif
76         .endm
77
78 /*
79  * Remove the address tag from a virtual address, if present.
80  */
81         .macro  clear_address_tag, dst, addr
82         tst     \addr, #(1 << 55)
83         bic     \dst, \addr, #(0xff << 56)
84         csel    \dst, \dst, \addr, eq
85         .endm
86
87 #endif