1 // SPDX-License-Identifier: GPL-2.0-or-later 1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* 2 /*
3 * Copyright (C) 2014 Imagination Technologies 3 * Copyright (C) 2014 Imagination Technologies Ltd.
4 * 4 *
5 * CPU PM notifiers for saving/restoring gener 5 * CPU PM notifiers for saving/restoring general CPU state.
6 */ 6 */
7 7
8 #include <linux/cpu_pm.h> 8 #include <linux/cpu_pm.h>
9 #include <linux/init.h> 9 #include <linux/init.h>
10 10
11 #include <asm/dsp.h> 11 #include <asm/dsp.h>
12 #include <asm/fpu.h> 12 #include <asm/fpu.h>
13 #include <asm/mmu_context.h> 13 #include <asm/mmu_context.h>
14 #include <asm/pm.h> 14 #include <asm/pm.h>
15 #include <asm/watch.h> 15 #include <asm/watch.h>
16 16
17 /* Used by PM helper macros in asm/pm.h */ 17 /* Used by PM helper macros in asm/pm.h */
18 struct mips_static_suspend_state mips_static_s 18 struct mips_static_suspend_state mips_static_suspend_state;
19 19
20 /** 20 /**
21 * mips_cpu_save() - Save general CPU state. 21 * mips_cpu_save() - Save general CPU state.
22 * Ensures that general CPU context is saved, 22 * Ensures that general CPU context is saved, notably FPU and DSP.
23 */ 23 */
24 static int mips_cpu_save(void) 24 static int mips_cpu_save(void)
25 { 25 {
26 /* Save FPU state */ 26 /* Save FPU state */
27 lose_fpu(1); 27 lose_fpu(1);
28 28
29 /* Save DSP state */ 29 /* Save DSP state */
30 save_dsp(current); 30 save_dsp(current);
31 31
32 return 0; 32 return 0;
33 } 33 }
34 34
35 /** 35 /**
36 * mips_cpu_restore() - Restore general CPU st 36 * mips_cpu_restore() - Restore general CPU state.
37 * Restores important CPU context. 37 * Restores important CPU context.
38 */ 38 */
39 static void mips_cpu_restore(void) 39 static void mips_cpu_restore(void)
40 { 40 {
41 unsigned int cpu = smp_processor_id(); 41 unsigned int cpu = smp_processor_id();
42 42
43 /* Restore ASID */ 43 /* Restore ASID */
44 if (current->mm) 44 if (current->mm)
45 write_c0_entryhi(cpu_asid(cpu, 45 write_c0_entryhi(cpu_asid(cpu, current->mm));
46 46
47 /* Restore DSP state */ 47 /* Restore DSP state */
48 restore_dsp(current); 48 restore_dsp(current);
49 49
50 /* Restore UserLocal */ 50 /* Restore UserLocal */
51 if (cpu_has_userlocal) 51 if (cpu_has_userlocal)
52 write_c0_userlocal(current_thr 52 write_c0_userlocal(current_thread_info()->tp_value);
53 53
54 /* Restore watch registers */ 54 /* Restore watch registers */
55 __restore_watch(current); 55 __restore_watch(current);
56 } 56 }
57 57
58 /** 58 /**
59 * mips_pm_notifier() - Notifier for preservin 59 * mips_pm_notifier() - Notifier for preserving general CPU context.
60 * @self: Notifier block. 60 * @self: Notifier block.
61 * @cmd: CPU PM event. 61 * @cmd: CPU PM event.
62 * @v: Private data (unused). 62 * @v: Private data (unused).
63 * 63 *
64 * This is called when a CPU power management 64 * This is called when a CPU power management event occurs, and is used to
65 * ensure that important CPU context is preser 65 * ensure that important CPU context is preserved across a CPU power down.
66 */ 66 */
67 static int mips_pm_notifier(struct notifier_bl 67 static int mips_pm_notifier(struct notifier_block *self, unsigned long cmd,
68 void *v) 68 void *v)
69 { 69 {
70 int ret; 70 int ret;
71 71
72 switch (cmd) { 72 switch (cmd) {
73 case CPU_PM_ENTER: 73 case CPU_PM_ENTER:
74 ret = mips_cpu_save(); 74 ret = mips_cpu_save();
75 if (ret) 75 if (ret)
76 return NOTIFY_STOP; 76 return NOTIFY_STOP;
77 break; 77 break;
78 case CPU_PM_ENTER_FAILED: 78 case CPU_PM_ENTER_FAILED:
79 case CPU_PM_EXIT: 79 case CPU_PM_EXIT:
80 mips_cpu_restore(); 80 mips_cpu_restore();
81 break; 81 break;
82 } 82 }
83 83
84 return NOTIFY_OK; 84 return NOTIFY_OK;
85 } 85 }
86 86
87 static struct notifier_block mips_pm_notifier_ 87 static struct notifier_block mips_pm_notifier_block = {
88 .notifier_call = mips_pm_notifier, 88 .notifier_call = mips_pm_notifier,
89 }; 89 };
90 90
91 static int __init mips_pm_init(void) 91 static int __init mips_pm_init(void)
92 { 92 {
93 return cpu_pm_register_notifier(&mips_ 93 return cpu_pm_register_notifier(&mips_pm_notifier_block);
94 } 94 }
95 arch_initcall(mips_pm_init); 95 arch_initcall(mips_pm_init);
96 96
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