1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * LoongArch specific sysrq operations.
4  *
5  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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/tlb.h>
15 
16 /*
17  * Dump TLB entries on all CPUs.
18  */
19 
20 static DEFINE_SPINLOCK(show_lock);
21 
sysrq_tlbdump_single(void * dummy)22 static void sysrq_tlbdump_single(void *dummy)
23 {
24 	unsigned long flags;
25 
26 	spin_lock_irqsave(&show_lock, flags);
27 
28 	pr_info("CPU%d:\n", smp_processor_id());
29 	dump_tlb_regs();
30 	pr_info("\n");
31 	dump_tlb_all();
32 	pr_info("\n");
33 
34 	spin_unlock_irqrestore(&show_lock, flags);
35 }
36 
37 #ifdef CONFIG_SMP
sysrq_tlbdump_othercpus(struct work_struct * dummy)38 static void sysrq_tlbdump_othercpus(struct work_struct *dummy)
39 {
40 	smp_call_function(sysrq_tlbdump_single, NULL, 0);
41 }
42 
43 static DECLARE_WORK(sysrq_tlbdump, sysrq_tlbdump_othercpus);
44 #endif
45 
sysrq_handle_tlbdump(int key)46 static void sysrq_handle_tlbdump(int key)
47 {
48 	sysrq_tlbdump_single(NULL);
49 #ifdef CONFIG_SMP
50 	schedule_work(&sysrq_tlbdump);
51 #endif
52 }
53 
54 static struct sysrq_key_op sysrq_tlbdump_op = {
55 	.handler        = sysrq_handle_tlbdump,
56 	.help_msg       = "show-tlbs(x)",
57 	.action_msg     = "Show TLB entries",
58 	.enable_mask	= SYSRQ_ENABLE_DUMP,
59 };
60 
loongarch_sysrq_init(void)61 static int __init loongarch_sysrq_init(void)
62 {
63 	return register_sysrq_key('x', &sysrq_tlbdump_op);
64 }
65 arch_initcall(loongarch_sysrq_init);
66