GNU Linux-libre 4.19.286-gnu1
[releases.git] / arch / mips / kernel / sysrq.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * MIPS specific sysrq operations.
4  *
5  * Copyright (C) 2015 Imagination Technologies Ltd.
6  */
7 #include <linux/init.h>
8 #include <linux/smp.h>
9 #include <linux/spinlock.h>
10 #include <linux/sysrq.h>
11 #include <linux/workqueue.h>
12
13 #include <asm/cpu-features.h>
14 #include <asm/mipsregs.h>
15 #include <asm/tlbdebug.h>
16
17 /*
18  * Dump TLB entries on all CPUs.
19  */
20
21 static DEFINE_SPINLOCK(show_lock);
22
23 static void sysrq_tlbdump_single(void *dummy)
24 {
25         unsigned long flags;
26
27         spin_lock_irqsave(&show_lock, flags);
28
29         pr_info("CPU%d:\n", smp_processor_id());
30         dump_tlb_regs();
31         pr_info("\n");
32         dump_tlb_all();
33         pr_info("\n");
34
35         spin_unlock_irqrestore(&show_lock, flags);
36 }
37
38 #ifdef CONFIG_SMP
39 static void sysrq_tlbdump_othercpus(struct work_struct *dummy)
40 {
41         smp_call_function(sysrq_tlbdump_single, NULL, 0);
42 }
43
44 static DECLARE_WORK(sysrq_tlbdump, sysrq_tlbdump_othercpus);
45 #endif
46
47 static void sysrq_handle_tlbdump(int key)
48 {
49         sysrq_tlbdump_single(NULL);
50 #ifdef CONFIG_SMP
51         schedule_work(&sysrq_tlbdump);
52 #endif
53 }
54
55 static struct sysrq_key_op sysrq_tlbdump_op = {
56         .handler        = sysrq_handle_tlbdump,
57         .help_msg       = "show-tlbs(x)",
58         .action_msg     = "Show TLB entries",
59         .enable_mask    = SYSRQ_ENABLE_DUMP,
60 };
61
62 static int __init mips_sysrq_init(void)
63 {
64         return register_sysrq_key('x', &sysrq_tlbdump_op);
65 }
66 arch_initcall(mips_sysrq_init);