arch/csky/kernel/process.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/module.h>
   5 #include <linux/version.h>
   6 #include <linux/sched.h>
   7 #include <linux/sched/task_stack.h>
   8 #include <linux/sched/debug.h>
   9 #include <linux/delay.h>
  10 #include <linux/kallsyms.h>
  11 #include <linux/uaccess.h>
  12 #include <linux/ptrace.h>
  13
  14 #include <asm/elf.h>
  15 #include <abi/reg_ops.h>
  16
  17 struct cpuinfo_csky cpu_data[NR_CPUS];
  18
  19 #ifdef CONFIG_STACKPROTECTOR
  20 #include <linux/stackprotector.h>
  21 unsigned long __stack_chk_guard __read_mostly;
  22 EXPORT_SYMBOL(__stack_chk_guard);
  23 #endif
  24
  25 asmlinkage void ret_from_fork(void);
  26 asmlinkage void ret_from_kernel_thread(void);
  27
  28 /*
  29  * Some archs flush debug and FPU info here
  30  */
  31 void flush_thread(void){}
  32
  33 int copy_thread(unsigned long clone_flags,
  34                 unsigned long usp,
  35                 unsigned long kthread_arg,
  36                 struct task_struct *p,
  37                 unsigned long tls)
  38 {
  39         struct switch_stack *childstack;
  40         struct pt_regs *childregs = task_pt_regs(p);
  41
  42 #ifdef CONFIG_CPU_HAS_FPU
  43         save_to_user_fp(&p->thread.user_fp);
  44 #endif
  45
  46         childstack = ((struct switch_stack *) childregs) - 1;
  47         memset(childstack, 0, sizeof(struct switch_stack));
  48
  49         /* setup thread.sp for switch_to !!! */
  50         p->thread.sp = (unsigned long)childstack;
  51
  52         if (unlikely(p->flags & PF_KTHREAD)) {
  53                 memset(childregs, 0, sizeof(struct pt_regs));
  54                 childstack->r15 = (unsigned long) ret_from_kernel_thread;
  55                 childstack->r10 = kthread_arg;
  56                 childstack->r9 = usp;
  57                 childregs->sr = mfcr("psr");
  58         } else {
  59                 *childregs = *(current_pt_regs());
  60                 if (usp)
  61                         childregs->usp = usp;
  62                 if (clone_flags & CLONE_SETTLS)
  63                         task_thread_info(p)->tp_value = childregs->tls
  64                                                       = tls;
  65
  66                 childregs->a0 = 0;
  67                 childstack->r15 = (unsigned long) ret_from_fork;
  68         }
  69
  70         return 0;
  71 }
  72
  73 /* Fill in the fpu structure for a core dump.  */
  74 int dump_fpu(struct pt_regs *regs, struct user_fp *fpu)
  75 {
  76         memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
  77         return 1;
  78 }
  79 EXPORT_SYMBOL(dump_fpu);
  80
  81 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
  82 {
  83         struct pt_regs *regs = task_pt_regs(tsk);
  84
  85         /* NOTE: usp is error value. */
  86         ELF_CORE_COPY_REGS((*pr_regs), regs)
  87
  88         return 1;
  89 }
  90
  91 #ifndef CONFIG_CPU_PM_NONE
  92 void arch_cpu_idle(void)
  93 {
  94 #ifdef CONFIG_CPU_PM_WAIT
  95         asm volatile("wait\n");
  96 #endif
  97
  98 #ifdef CONFIG_CPU_PM_DOZE
  99         asm volatile("doze\n");
 100 #endif
 101
 102 #ifdef CONFIG_CPU_PM_STOP
 103         asm volatile("stop\n");
 104 #endif
 105         raw_local_irq_enable();
 106 }
 107 #endif