1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Hibernation low level support for RISCV.
4 *
5 * Copyright (C) 2023 StarFive Technology Co.,
6 *
7 * Author: Jee Heng Sia <jeeheng.sia@starfivete
8 */
9
10 #include <asm/asm.h>
11 #include <asm/asm-offsets.h>
12 #include <asm/assembler.h>
13 #include <asm/csr.h>
14
15 #include <linux/linkage.h>
16
17 /*
18 * int __hibernate_cpu_resume(void)
19 * Switch back to the hibernated image's page
20 * context.
21 *
22 * Always returns 0
23 */
24 SYM_FUNC_START(__hibernate_cpu_resume)
25 /* switch to hibernated image's page t
26 csrw CSR_SATP, s0
27 sfence.vma
28
29 REG_L a0, hibernate_cpu_context
30
31 suspend_restore_regs
32
33 /* Return zero value. */
34 mv a0, zero
35
36 ret
37 SYM_FUNC_END(__hibernate_cpu_resume)
38
39 /*
40 * Prepare to restore the image.
41 * a0: satp of saved page tables.
42 * a1: satp of temporary page tables.
43 * a2: cpu_resume.
44 */
45 SYM_FUNC_START(hibernate_restore_image)
46 mv s0, a0
47 mv s1, a1
48 mv s2, a2
49 REG_L s4, restore_pblist
50 REG_L a1, relocated_restore_code
51
52 jr a1
53 SYM_FUNC_END(hibernate_restore_image)
54
55 /*
56 * The below code will be executed from a 'saf
57 * It first switches to the temporary page tab
58 * back to the original memory location. Final
59 * to restore the CPU context.
60 */
61 SYM_FUNC_START(hibernate_core_restore_code)
62 /* switch to temp page table. */
63 csrw satp, s1
64 sfence.vma
65 .Lcopy:
66 /* The below code will restore the hib
67 REG_L a1, HIBERN_PBE_ADDR(s4)
68 REG_L a0, HIBERN_PBE_ORIG(s4)
69
70 copy_page a0, a1
71
72 REG_L s4, HIBERN_PBE_NEXT(s4)
73 bnez s4, .Lcopy
74
75 jr s2
76 SYM_FUNC_END(hibernate_core_restore_code)
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