Commit | Line | Data |
---|---|---|
de818bd4 | 1 | #include <linux/ftrace.h> |
fb4a9602 | 2 | #include <linux/percpu.h> |
95322526 LP |
3 | #include <linux/slab.h> |
4 | #include <asm/cacheflush.h> | |
95322526 LP |
5 | #include <asm/debug-monitors.h> |
6 | #include <asm/pgtable.h> | |
7 | #include <asm/memory.h> | |
f43c2718 | 8 | #include <asm/mmu_context.h> |
95322526 LP |
9 | #include <asm/smp_plat.h> |
10 | #include <asm/suspend.h> | |
11 | #include <asm/tlbflush.h> | |
12 | ||
95322526 | 13 | /* |
cabe1c81 JM |
14 | * This is allocated by cpu_suspend_init(), and used to store a pointer to |
15 | * the 'struct sleep_stack_data' the contains a particular CPUs state. | |
95322526 | 16 | */ |
cabe1c81 | 17 | unsigned long *sleep_save_stash; |
95322526 | 18 | |
65c021bb LP |
19 | /* |
20 | * This hook is provided so that cpu_suspend code can restore HW | |
21 | * breakpoints as early as possible in the resume path, before reenabling | |
22 | * debug exceptions. Code cannot be run from a CPU PM notifier since by the | |
23 | * time the notifier runs debug exceptions might have been enabled already, | |
24 | * with HW breakpoints registers content still in an unknown state. | |
25 | */ | |
01b305a2 | 26 | static void (*hw_breakpoint_restore)(void *); |
65c021bb LP |
27 | void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) |
28 | { | |
29 | /* Prevent multiple restore hook initializations */ | |
30 | if (WARN_ON(hw_breakpoint_restore)) | |
31 | return; | |
32 | hw_breakpoint_restore = hw_bp_restore; | |
33 | } | |
34 | ||
adc9b2df JM |
35 | void notrace __cpu_suspend_exit(void) |
36 | { | |
37 | /* | |
38 | * We are resuming from reset with the idmap active in TTBR0_EL1. | |
39 | * We must uninstall the idmap and restore the expected MMU | |
40 | * state before we can possibly return to userspace. | |
41 | */ | |
42 | cpu_uninstall_idmap(); | |
43 | ||
44 | /* | |
45 | * Restore per-cpu offset before any kernel | |
46 | * subsystem relying on it has a chance to run. | |
47 | */ | |
48 | set_my_cpu_offset(per_cpu_offset(smp_processor_id())); | |
49 | ||
50 | /* | |
51 | * Restore HW breakpoint registers to sane values | |
52 | * before debug exceptions are possibly reenabled | |
53 | * through local_dbg_restore. | |
54 | */ | |
55 | if (hw_breakpoint_restore) | |
56 | hw_breakpoint_restore(NULL); | |
57 | } | |
58 | ||
714f5992 | 59 | /* |
af391b15 | 60 | * cpu_suspend |
714f5992 LP |
61 | * |
62 | * arg: argument to pass to the finisher function | |
63 | * fn: finisher function pointer | |
64 | * | |
65 | */ | |
af391b15 | 66 | int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) |
714f5992 | 67 | { |
adc9b2df | 68 | int ret = 0; |
714f5992 | 69 | unsigned long flags; |
adc9b2df | 70 | struct sleep_stack_data state; |
95322526 LP |
71 | |
72 | /* | |
73 | * From this point debug exceptions are disabled to prevent | |
74 | * updates to mdscr register (saved and restored along with | |
75 | * general purpose registers) from kernel debuggers. | |
76 | */ | |
77 | local_dbg_save(flags); | |
78 | ||
de818bd4 LP |
79 | /* |
80 | * Function graph tracer state gets incosistent when the kernel | |
81 | * calls functions that never return (aka suspend finishers) hence | |
82 | * disable graph tracing during their execution. | |
83 | */ | |
84 | pause_graph_tracing(); | |
85 | ||
adc9b2df JM |
86 | if (__cpu_suspend_enter(&state)) { |
87 | /* Call the suspend finisher */ | |
88 | ret = fn(arg); | |
fb4a9602 | 89 | |
65c021bb | 90 | /* |
adc9b2df JM |
91 | * Never gets here, unless the suspend finisher fails. |
92 | * Successful cpu_suspend() should return from cpu_resume(), | |
93 | * returning through this code path is considered an error | |
94 | * If the return value is set to 0 force ret = -EOPNOTSUPP | |
95 | * to make sure a proper error condition is propagated | |
65c021bb | 96 | */ |
adc9b2df JM |
97 | if (!ret) |
98 | ret = -EOPNOTSUPP; | |
99 | } else { | |
100 | __cpu_suspend_exit(); | |
95322526 LP |
101 | } |
102 | ||
de818bd4 LP |
103 | unpause_graph_tracing(); |
104 | ||
95322526 LP |
105 | /* |
106 | * Restore pstate flags. OS lock and mdscr have been already | |
107 | * restored, so from this point onwards, debugging is fully | |
108 | * renabled if it was enabled when core started shutdown. | |
109 | */ | |
110 | local_dbg_restore(flags); | |
111 | ||
112 | return ret; | |
113 | } | |
114 | ||
18ab7db6 | 115 | static int __init cpu_suspend_init(void) |
95322526 | 116 | { |
95322526 | 117 | /* ctx_ptr is an array of physical addresses */ |
cabe1c81 JM |
118 | sleep_save_stash = kcalloc(mpidr_hash_size(), sizeof(*sleep_save_stash), |
119 | GFP_KERNEL); | |
95322526 | 120 | |
cabe1c81 | 121 | if (WARN_ON(!sleep_save_stash)) |
95322526 LP |
122 | return -ENOMEM; |
123 | ||
95322526 LP |
124 | return 0; |
125 | } | |
126 | early_initcall(cpu_suspend_init); |