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82869ac5 JM |
1 | /* |
2 | * Hibernate low-level support | |
3 | * | |
4 | * Copyright (C) 2016 ARM Ltd. | |
5 | * Author: James Morse <james.morse@arm.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | #include <linux/linkage.h> | |
20 | #include <linux/errno.h> | |
21 | ||
22 | #include <asm/asm-offsets.h> | |
23 | #include <asm/assembler.h> | |
24 | #include <asm/cputype.h> | |
25 | #include <asm/memory.h> | |
26 | #include <asm/page.h> | |
27 | #include <asm/virt.h> | |
28 | ||
29 | /* | |
30 | * To prevent the possibility of old and new partial table walks being visible | |
31 | * in the tlb, switch the ttbr to a zero page when we invalidate the old | |
32 | * records. D4.7.1 'General TLB maintenance requirements' in ARM DDI 0487A.i | |
33 | * Even switching to our copied tables will cause a changed output address at | |
34 | * each stage of the walk. | |
35 | */ | |
529c4b05 KM |
36 | .macro break_before_make_ttbr_switch zero_page, page_table, tmp |
37 | phys_to_ttbr \zero_page, \tmp | |
38 | msr ttbr1_el1, \tmp | |
82869ac5 | 39 | isb |
0a7d87a7 MR |
40 | tlbi vmalle1 |
41 | dsb nsh | |
529c4b05 KM |
42 | phys_to_ttbr \page_table, \tmp |
43 | msr ttbr1_el1, \tmp | |
82869ac5 JM |
44 | isb |
45 | .endm | |
46 | ||
47 | ||
48 | /* | |
49 | * Resume from hibernate | |
50 | * | |
51 | * Loads temporary page tables then restores the memory image. | |
52 | * Finally branches to cpu_resume() to restore the state saved by | |
53 | * swsusp_arch_suspend(). | |
54 | * | |
55 | * Because this code has to be copied to a 'safe' page, it can't call out to | |
56 | * other functions by PC-relative address. Also remember that it may be | |
57 | * mid-way through over-writing other functions. For this reason it contains | |
58 | * code from flush_icache_range() and uses the copy_page() macro. | |
59 | * | |
60 | * This 'safe' page is mapped via ttbr0, and executed from there. This function | |
61 | * switches to a copy of the linear map in ttbr1, performs the restore, then | |
62 | * switches ttbr1 to the original kernel's swapper_pg_dir. | |
63 | * | |
64 | * All of memory gets written to, including code. We need to clean the kernel | |
65 | * text to the Point of Coherence (PoC) before secondary cores can be booted. | |
66 | * Because the kernel modules and executable pages mapped to user space are | |
67 | * also written as data, we clean all pages we touch to the Point of | |
68 | * Unification (PoU). | |
69 | * | |
70 | * x0: physical address of temporary page tables | |
71 | * x1: physical address of swapper page tables | |
72 | * x2: address of cpu_resume | |
73 | * x3: linear map address of restore_pblist in the current kernel | |
74 | * x4: physical address of __hyp_stub_vectors, or 0 | |
75 | * x5: physical address of a zero page that remains zero after resume | |
76 | */ | |
77 | .pushsection ".hibernate_exit.text", "ax" | |
78 | ENTRY(swsusp_arch_suspend_exit) | |
79 | /* | |
80 | * We execute from ttbr0, change ttbr1 to our copied linear map tables | |
81 | * with a break-before-make via the zero page | |
82 | */ | |
529c4b05 | 83 | break_before_make_ttbr_switch x5, x0, x6 |
82869ac5 JM |
84 | |
85 | mov x21, x1 | |
86 | mov x30, x2 | |
87 | mov x24, x4 | |
88 | mov x25, x5 | |
89 | ||
90 | /* walk the restore_pblist and use copy_page() to over-write memory */ | |
91 | mov x19, x3 | |
92 | ||
93 | 1: ldr x10, [x19, #HIBERN_PBE_ORIG] | |
94 | mov x0, x10 | |
95 | ldr x1, [x19, #HIBERN_PBE_ADDR] | |
96 | ||
97 | copy_page x0, x1, x2, x3, x4, x5, x6, x7, x8, x9 | |
98 | ||
99 | add x1, x10, #PAGE_SIZE | |
100 | /* Clean the copied page to PoU - based on flush_icache_range() */ | |
072f0a63 | 101 | raw_dcache_line_size x2, x3 |
82869ac5 JM |
102 | sub x3, x2, #1 |
103 | bic x4, x10, x3 | |
104 | 2: dc cvau, x4 /* clean D line / unified line */ | |
105 | add x4, x4, x2 | |
106 | cmp x4, x1 | |
107 | b.lo 2b | |
108 | ||
109 | ldr x19, [x19, #HIBERN_PBE_NEXT] | |
110 | cbnz x19, 1b | |
111 | dsb ish /* wait for PoU cleaning to finish */ | |
112 | ||
113 | /* switch to the restored kernels page tables */ | |
529c4b05 | 114 | break_before_make_ttbr_switch x25, x21, x6 |
82869ac5 JM |
115 | |
116 | ic ialluis | |
117 | dsb ish | |
118 | isb | |
119 | ||
120 | cbz x24, 3f /* Do we need to re-initialise EL2? */ | |
121 | hvc #0 | |
122 | 3: ret | |
123 | ||
124 | .ltorg | |
125 | ENDPROC(swsusp_arch_suspend_exit) | |
126 | ||
127 | /* | |
128 | * Restore the hyp stub. | |
129 | * This must be done before the hibernate page is unmapped by _cpu_resume(), | |
130 | * but happens before any of the hyp-stub's code is cleaned to PoC. | |
131 | * | |
132 | * x24: The physical address of __hyp_stub_vectors | |
133 | */ | |
134 | el1_sync: | |
135 | msr vbar_el2, x24 | |
136 | eret | |
137 | ENDPROC(el1_sync) | |
138 | ||
139 | .macro invalid_vector label | |
140 | \label: | |
141 | b \label | |
142 | ENDPROC(\label) | |
143 | .endm | |
144 | ||
145 | invalid_vector el2_sync_invalid | |
146 | invalid_vector el2_irq_invalid | |
147 | invalid_vector el2_fiq_invalid | |
148 | invalid_vector el2_error_invalid | |
149 | invalid_vector el1_sync_invalid | |
150 | invalid_vector el1_irq_invalid | |
151 | invalid_vector el1_fiq_invalid | |
152 | invalid_vector el1_error_invalid | |
153 | ||
154 | /* el2 vectors - switch el2 here while we restore the memory image. */ | |
155 | .align 11 | |
156 | ENTRY(hibernate_el2_vectors) | |
157 | ventry el2_sync_invalid // Synchronous EL2t | |
158 | ventry el2_irq_invalid // IRQ EL2t | |
159 | ventry el2_fiq_invalid // FIQ EL2t | |
160 | ventry el2_error_invalid // Error EL2t | |
161 | ||
162 | ventry el2_sync_invalid // Synchronous EL2h | |
163 | ventry el2_irq_invalid // IRQ EL2h | |
164 | ventry el2_fiq_invalid // FIQ EL2h | |
165 | ventry el2_error_invalid // Error EL2h | |
166 | ||
167 | ventry el1_sync // Synchronous 64-bit EL1 | |
168 | ventry el1_irq_invalid // IRQ 64-bit EL1 | |
169 | ventry el1_fiq_invalid // FIQ 64-bit EL1 | |
170 | ventry el1_error_invalid // Error 64-bit EL1 | |
171 | ||
172 | ventry el1_sync_invalid // Synchronous 32-bit EL1 | |
173 | ventry el1_irq_invalid // IRQ 32-bit EL1 | |
174 | ventry el1_fiq_invalid // FIQ 32-bit EL1 | |
175 | ventry el1_error_invalid // Error 32-bit EL1 | |
176 | END(hibernate_el2_vectors) | |
177 | ||
178 | .popsection |