1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/ftrace.h> |
3 | #include <linux/init.h> |
4 | #include <linux/slab.h> |
5 | #include <linux/mm_types.h> |
6 | #include <linux/pgtable.h> |
7 | |
8 | #include <asm/bugs.h> |
9 | #include <asm/cacheflush.h> |
10 | #include <asm/idmap.h> |
11 | #include <asm/page.h> |
12 | #include <asm/smp_plat.h> |
13 | #include <asm/suspend.h> |
14 | #include <asm/tlbflush.h> |
15 | |
16 | extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid); |
17 | extern void cpu_resume_mmu(void); |
18 | |
19 | #ifdef CONFIG_MMU |
20 | int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) |
21 | { |
22 | struct mm_struct *mm = current->active_mm; |
23 | u32 __mpidr = cpu_logical_map(smp_processor_id()); |
24 | int ret; |
25 | |
26 | if (!idmap_pgd) |
27 | return -EINVAL; |
28 | |
29 | /* |
30 | * Function graph tracer state gets incosistent when the kernel |
31 | * calls functions that never return (aka suspend finishers) hence |
32 | * disable graph tracing during their execution. |
33 | */ |
34 | pause_graph_tracing(); |
35 | |
36 | /* |
37 | * Provide a temporary page table with an identity mapping for |
38 | * the MMU-enable code, required for resuming. On successful |
39 | * resume (indicated by a zero return code), we need to switch |
40 | * back to the correct page tables. |
41 | */ |
42 | ret = __cpu_suspend(arg, fn, cpuid: __mpidr); |
43 | |
44 | unpause_graph_tracing(); |
45 | |
46 | if (ret == 0) { |
47 | cpu_switch_mm(mm->pgd, mm); |
48 | local_flush_bp_all(); |
49 | local_flush_tlb_all(); |
50 | check_other_bugs(); |
51 | } |
52 | |
53 | return ret; |
54 | } |
55 | #else |
56 | int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) |
57 | { |
58 | u32 __mpidr = cpu_logical_map(smp_processor_id()); |
59 | int ret; |
60 | |
61 | pause_graph_tracing(); |
62 | ret = __cpu_suspend(arg, fn, __mpidr); |
63 | unpause_graph_tracing(); |
64 | |
65 | return ret; |
66 | } |
67 | #define idmap_pgd NULL |
68 | #endif |
69 | |
70 | /* |
71 | * This is called by __cpu_suspend() to save the state, and do whatever |
72 | * flushing is required to ensure that when the CPU goes to sleep we have |
73 | * the necessary data available when the caches are not searched. |
74 | */ |
75 | void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) |
76 | { |
77 | u32 *ctx = ptr; |
78 | |
79 | *save_ptr = virt_to_phys(ptr); |
80 | |
81 | /* This must correspond to the LDM in cpu_resume() assembly */ |
82 | *ptr++ = virt_to_phys(idmap_pgd); |
83 | *ptr++ = sp; |
84 | *ptr++ = virt_to_phys(cpu_do_resume); |
85 | |
86 | cpu_do_suspend(ptr); |
87 | |
88 | flush_cache_louis(); |
89 | |
90 | /* |
91 | * flush_cache_louis does not guarantee that |
92 | * save_ptr and ptr are cleaned to main memory, |
93 | * just up to the Level of Unification Inner Shareable. |
94 | * Since the context pointer and context itself |
95 | * are to be retrieved with the MMU off that |
96 | * data must be cleaned from all cache levels |
97 | * to main memory using "area" cache primitives. |
98 | */ |
99 | __cpuc_flush_dcache_area(ctx, ptrsz); |
100 | __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr)); |
101 | |
102 | outer_clean_range(*save_ptr, *save_ptr + ptrsz); |
103 | outer_clean_range(virt_to_phys(save_ptr), |
104 | virt_to_phys(save_ptr) + sizeof(*save_ptr)); |
105 | } |
106 | |
107 | extern struct sleep_save_sp sleep_save_sp; |
108 | |
109 | static int cpu_suspend_alloc_sp(void) |
110 | { |
111 | void *ctx_ptr; |
112 | /* ctx_ptr is an array of physical addresses */ |
113 | ctx_ptr = kcalloc(n: mpidr_hash_size(), size: sizeof(u32), GFP_KERNEL); |
114 | |
115 | if (WARN_ON(!ctx_ptr)) |
116 | return -ENOMEM; |
117 | sleep_save_sp.save_ptr_stash = ctx_ptr; |
118 | sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr); |
119 | sync_cache_w(&sleep_save_sp); |
120 | return 0; |
121 | } |
122 | early_initcall(cpu_suspend_alloc_sp); |
123 | |