arch/loongarch/kernel/sysrq.c

   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
  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
  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
  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
  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);