1 // SPDX-License-Identifier: GPL-2.0-or-later <<
2 /* 1 /*
3 * Copyright (C) 2014 Imagination Technologies 2 * Copyright (C) 2014 Imagination Technologies Ltd.
>> 3 *
>> 4 * This program is free software; you can redistribute it and/or modify it
>> 5 * under the terms of the GNU General Public License as published by the
>> 6 * Free Software Foundation; either version 2 of the License, or (at your
>> 7 * option) any later version.
4 * 8 *
5 * CPU PM notifiers for saving/restoring gener 9 * CPU PM notifiers for saving/restoring general CPU state.
6 */ 10 */
7 11
8 #include <linux/cpu_pm.h> 12 #include <linux/cpu_pm.h>
9 #include <linux/init.h> 13 #include <linux/init.h>
10 14
11 #include <asm/dsp.h> 15 #include <asm/dsp.h>
12 #include <asm/fpu.h> 16 #include <asm/fpu.h>
13 #include <asm/mmu_context.h> 17 #include <asm/mmu_context.h>
14 #include <asm/pm.h> 18 #include <asm/pm.h>
15 #include <asm/watch.h> 19 #include <asm/watch.h>
16 20
17 /* Used by PM helper macros in asm/pm.h */ 21 /* Used by PM helper macros in asm/pm.h */
18 struct mips_static_suspend_state mips_static_s 22 struct mips_static_suspend_state mips_static_suspend_state;
19 23
20 /** 24 /**
21 * mips_cpu_save() - Save general CPU state. 25 * mips_cpu_save() - Save general CPU state.
22 * Ensures that general CPU context is saved, 26 * Ensures that general CPU context is saved, notably FPU and DSP.
23 */ 27 */
24 static int mips_cpu_save(void) 28 static int mips_cpu_save(void)
25 { 29 {
26 /* Save FPU state */ 30 /* Save FPU state */
27 lose_fpu(1); 31 lose_fpu(1);
28 32
29 /* Save DSP state */ 33 /* Save DSP state */
30 save_dsp(current); 34 save_dsp(current);
31 35
32 return 0; 36 return 0;
33 } 37 }
34 38
35 /** 39 /**
36 * mips_cpu_restore() - Restore general CPU st 40 * mips_cpu_restore() - Restore general CPU state.
37 * Restores important CPU context. 41 * Restores important CPU context.
38 */ 42 */
39 static void mips_cpu_restore(void) 43 static void mips_cpu_restore(void)
40 { 44 {
41 unsigned int cpu = smp_processor_id(); 45 unsigned int cpu = smp_processor_id();
42 46
43 /* Restore ASID */ 47 /* Restore ASID */
44 if (current->mm) 48 if (current->mm)
45 write_c0_entryhi(cpu_asid(cpu, 49 write_c0_entryhi(cpu_asid(cpu, current->mm));
46 50
47 /* Restore DSP state */ 51 /* Restore DSP state */
48 restore_dsp(current); 52 restore_dsp(current);
49 53
50 /* Restore UserLocal */ 54 /* Restore UserLocal */
51 if (cpu_has_userlocal) 55 if (cpu_has_userlocal)
52 write_c0_userlocal(current_thr 56 write_c0_userlocal(current_thread_info()->tp_value);
53 57
54 /* Restore watch registers */ 58 /* Restore watch registers */
55 __restore_watch(current); 59 __restore_watch(current);
56 } 60 }
57 61
58 /** 62 /**
59 * mips_pm_notifier() - Notifier for preservin 63 * mips_pm_notifier() - Notifier for preserving general CPU context.
60 * @self: Notifier block. 64 * @self: Notifier block.
61 * @cmd: CPU PM event. 65 * @cmd: CPU PM event.
62 * @v: Private data (unused). 66 * @v: Private data (unused).
63 * 67 *
64 * This is called when a CPU power management 68 * This is called when a CPU power management event occurs, and is used to
65 * ensure that important CPU context is preser 69 * ensure that important CPU context is preserved across a CPU power down.
66 */ 70 */
67 static int mips_pm_notifier(struct notifier_bl 71 static int mips_pm_notifier(struct notifier_block *self, unsigned long cmd,
68 void *v) 72 void *v)
69 { 73 {
70 int ret; 74 int ret;
71 75
72 switch (cmd) { 76 switch (cmd) {
73 case CPU_PM_ENTER: 77 case CPU_PM_ENTER:
74 ret = mips_cpu_save(); 78 ret = mips_cpu_save();
75 if (ret) 79 if (ret)
76 return NOTIFY_STOP; 80 return NOTIFY_STOP;
77 break; 81 break;
78 case CPU_PM_ENTER_FAILED: 82 case CPU_PM_ENTER_FAILED:
79 case CPU_PM_EXIT: 83 case CPU_PM_EXIT:
80 mips_cpu_restore(); 84 mips_cpu_restore();
81 break; 85 break;
82 } 86 }
83 87
84 return NOTIFY_OK; 88 return NOTIFY_OK;
85 } 89 }
86 90
87 static struct notifier_block mips_pm_notifier_ 91 static struct notifier_block mips_pm_notifier_block = {
88 .notifier_call = mips_pm_notifier, 92 .notifier_call = mips_pm_notifier,
89 }; 93 };
90 94
91 static int __init mips_pm_init(void) 95 static int __init mips_pm_init(void)
92 { 96 {
93 return cpu_pm_register_notifier(&mips_ 97 return cpu_pm_register_notifier(&mips_pm_notifier_block);
94 } 98 }
95 arch_initcall(mips_pm_init); 99 arch_initcall(mips_pm_init);
96 100
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