arch/h8300/kernel/process.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/arch/h8300/kernel/process.c
   4  *
   5  * Yoshinori Sato <ysato@users.sourceforge.jp>
   6  *
   7  *  Based on:
   8  *
   9  *  linux/arch/m68knommu/kernel/process.c
  10  *
  11  *  Copyright (C) 1998  D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
  12  *                      Kenneth Albanowski <kjahds@kjahds.com>,
  13  *                      The Silver Hammer Group, Ltd.
  14  *
  15  *  linux/arch/m68k/kernel/process.c
  16  *
  17  *  Copyright (C) 1995  Hamish Macdonald
  18  *
  19  *  68060 fixes by Jesper Skov
  20  */
  21
  22 /*
  23  * This file handles the architecture-dependent parts of process handling..
  24  */
  25
  26 #include <linux/errno.h>
  27 #include <linux/module.h>
  28 #include <linux/sched.h>
  29 #include <linux/sched/debug.h>
  30 #include <linux/sched/task.h>
  31 #include <linux/sched/task_stack.h>
  32 #include <linux/kernel.h>
  33 #include <linux/mm.h>
  34 #include <linux/smp.h>
  35 #include <linux/stddef.h>
  36 #include <linux/unistd.h>
  37 #include <linux/ptrace.h>
  38 #include <linux/user.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/reboot.h>
  41 #include <linux/fs.h>
  42 #include <linux/slab.h>
  43 #include <linux/rcupdate.h>
  44
  45 #include <linux/uaccess.h>
  46 #include <asm/traps.h>
  47 #include <asm/setup.h>
  48
  49 void (*pm_power_off)(void) = NULL;
  50 EXPORT_SYMBOL(pm_power_off);
  51
  52 asmlinkage void ret_from_fork(void);
  53 asmlinkage void ret_from_kernel_thread(void);
  54
  55 /*
  56  * The idle loop on an H8/300..
  57  */
  58 void arch_cpu_idle(void)
  59 {
  60         local_irq_enable();
  61         __asm__("sleep");
  62 }
  63
  64 void machine_restart(char *__unused)
  65 {
  66         local_irq_disable();
  67         __asm__("jmp @@0");
  68 }
  69
  70 void machine_halt(void)
  71 {
  72         local_irq_disable();
  73         __asm__("sleep");
  74         for (;;)
  75                 ;
  76 }
  77
  78 void machine_power_off(void)
  79 {
  80         local_irq_disable();
  81         __asm__("sleep");
  82         for (;;)
  83                 ;
  84 }
  85
  86 void show_regs(struct pt_regs *regs)
  87 {
  88         show_regs_print_info(KERN_DEFAULT);
  89
  90         pr_notice("\n");
  91         pr_notice("PC: %08lx  Status: %02x\n",
  92                regs->pc, regs->ccr);
  93         pr_notice("ORIG_ER0: %08lx ER0: %08lx ER1: %08lx\n",
  94                regs->orig_er0, regs->er0, regs->er1);
  95         pr_notice("ER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx\n",
  96                regs->er2, regs->er3, regs->er4, regs->er5);
  97         pr_notice("ER6' %08lx ", regs->er6);
  98         if (user_mode(regs))
  99                 printk("USP: %08lx\n", rdusp());
 100         else
 101                 printk("\n");
 102 }
 103
 104 void flush_thread(void)
 105 {
 106 }
 107
 108 int copy_thread(unsigned long clone_flags, unsigned long usp,
 109                 unsigned long topstk, struct task_struct *p, unsigned long tls)
 110 {
 111         struct pt_regs *childregs;
 112
 113         childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
 114
 115         if (unlikely(p->flags & PF_KTHREAD)) {
 116                 memset(childregs, 0, sizeof(struct pt_regs));
 117                 childregs->retpc = (unsigned long) ret_from_kernel_thread;
 118                 childregs->er4 = topstk; /* arg */
 119                 childregs->er5 = usp; /* fn */
 120         }  else {
 121                 *childregs = *current_pt_regs();
 122                 childregs->er0 = 0;
 123                 childregs->retpc = (unsigned long) ret_from_fork;
 124                 p->thread.usp = usp ?: rdusp();
 125         }
 126         p->thread.ksp = (unsigned long)childregs;
 127
 128         return 0;
 129 }
 130
 131 unsigned long get_wchan(struct task_struct *p)
 132 {
 133         unsigned long fp, pc;
 134         unsigned long stack_page;
 135         int count = 0;
 136
 137         if (!p || p == current || p->state == TASK_RUNNING)
 138                 return 0;
 139
 140         stack_page = (unsigned long)p;
 141         fp = ((struct pt_regs *)p->thread.ksp)->er6;
 142         do {
 143                 if (fp < stack_page+sizeof(struct thread_info) ||
 144                     fp >= 8184+stack_page)
 145                         return 0;
 146                 pc = ((unsigned long *)fp)[1];
 147                 if (!in_sched_functions(pc))
 148                         return pc;
 149                 fp = *(unsigned long *) fp;
 150         } while (count++ < 16);
 151         return 0;
 152 }
 153
 154 /* generic sys_clone is not enough registers */
 155 asmlinkage int sys_clone(unsigned long __user *args)
 156 {
 157         unsigned long clone_flags;
 158         unsigned long  newsp;
 159         uintptr_t parent_tidptr;
 160         uintptr_t child_tidptr;
 161         struct kernel_clone_args kargs = {};
 162
 163         get_user(clone_flags, &args[0]);
 164         get_user(newsp, &args[1]);
 165         get_user(parent_tidptr, &args[2]);
 166         get_user(child_tidptr, &args[3]);
 167
 168         kargs.flags             = (lower_32_bits(clone_flags) & ~CSIGNAL);
 169         kargs.pidfd             = (int __user *)parent_tidptr;
 170         kargs.child_tid         = (int __user *)child_tidptr;
 171         kargs.parent_tid        = (int __user *)parent_tidptr;
 172         kargs.exit_signal       = (lower_32_bits(clone_flags) & CSIGNAL);
 173         kargs.stack             = newsp;
 174
 175         return _do_fork(&kargs);
 176 }