arch/mips/kernel/sysrq.c

   1 /*
   2  * MIPS specific sysrq operations.
   3  *
   4  * Copyright (C) 2015 Imagination Technologies Ltd.
   5  */
   6 #include <linux/init.h>
   7 #include <linux/smp.h>
   8 #include <linux/spinlock.h>
   9 #include <linux/sysrq.h>
  10 #include <linux/workqueue.h>
  11
  12 #include <asm/cpu-features.h>
  13 #include <asm/mipsregs.h>
  14 #include <asm/tlbdebug.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         const int field = 2 * sizeof(unsigned long);
  25         unsigned long flags;
  26
  27         spin_lock_irqsave(&show_lock, flags);
  28
  29         pr_info("CPU%d:\n", smp_processor_id());
  30         pr_info("Index  : %0x\n", read_c0_index());
  31         pr_info("Pagemask: %0x\n", read_c0_pagemask());
  32         pr_info("EntryHi : %0*lx\n", field, read_c0_entryhi());
  33         pr_info("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
  34         pr_info("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
  35         pr_info("Wired   : %0x\n", read_c0_wired());
  36         pr_info("Pagegrain: %0x\n", read_c0_pagegrain());
  37         if (cpu_has_htw) {
  38                 pr_info("PWField : %0*lx\n", field, read_c0_pwfield());
  39                 pr_info("PWSize  : %0*lx\n", field, read_c0_pwsize());
  40                 pr_info("PWCtl   : %0x\n", read_c0_pwctl());
  41         }
  42         pr_info("\n");
  43         dump_tlb_all();
  44         pr_info("\n");
  45
  46         spin_unlock_irqrestore(&show_lock, flags);
  47 }
  48
  49 #ifdef CONFIG_SMP
  50 static void sysrq_tlbdump_othercpus(struct work_struct *dummy)
  51 {
  52         smp_call_function(sysrq_tlbdump_single, NULL, 0);
  53 }
  54
  55 static DECLARE_WORK(sysrq_tlbdump, sysrq_tlbdump_othercpus);
  56 #endif
  57
  58 static void sysrq_handle_tlbdump(int key)
  59 {
  60         sysrq_tlbdump_single(NULL);
  61 #ifdef CONFIG_SMP
  62         schedule_work(&sysrq_tlbdump);
  63 #endif
  64 }
  65
  66 static struct sysrq_key_op sysrq_tlbdump_op = {
  67         .handler        = sysrq_handle_tlbdump,
  68         .help_msg       = "show-tlbs(x)",
  69         .action_msg     = "Show TLB entries",
  70         .enable_mask    = SYSRQ_ENABLE_DUMP,
  71 };
  72
  73 static int __init mips_sysrq_init(void)
  74 {
  75         return register_sysrq_key('x', &sysrq_tlbdump_op);
  76 }
  77 arch_initcall(mips_sysrq_init);