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/sched.h>
   6 #include <linux/sched/task_stack.h>
   7 #include <linux/sched/debug.h>
   8 #include <linux/delay.h>
   9 #include <linux/kallsyms.h>
  10 #include <linux/uaccess.h>
  11 #include <linux/ptrace.h>
  12 #include <linux/elfcore.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(struct task_struct *p, const struct kernel_clone_args *args)
  34 {
  35         unsigned long clone_flags = args->flags;
  36         unsigned long usp = args->stack;
  37         unsigned long tls = args->tls;
  38         struct switch_stack *childstack;
  39         struct pt_regs *childregs = task_pt_regs(p);
  40
  41 #ifdef CONFIG_CPU_HAS_FPU
  42         save_to_user_fp(&p->thread.user_fp);
  43 #endif
  44
  45         childstack = ((struct switch_stack *) childregs) - 1;
  46         memset(childstack, 0, sizeof(struct switch_stack));
  47
  48         /* setup thread.sp for switch_to !!! */
  49         p->thread.sp = (unsigned long)childstack;
  50
  51         if (unlikely(args->fn)) {
  52                 memset(childregs, 0, sizeof(struct pt_regs));
  53                 childstack->r15 = (unsigned long) ret_from_kernel_thread;
  54                 childstack->r10 = (unsigned long) args->fn_arg;
  55                 childstack->r9 = (unsigned long) args->fn;
  56                 childregs->sr = mfcr("psr");
  57         } else {
  58                 *childregs = *(current_pt_regs());
  59                 if (usp)
  60                         childregs->usp = usp;
  61                 if (clone_flags & CLONE_SETTLS)
  62                         task_thread_info(p)->tp_value = childregs->tls
  63                                                       = tls;
  64
  65                 childregs->a0 = 0;
  66                 childstack->r15 = (unsigned long) ret_from_fork;
  67         }
  68
  69         return 0;
  70 }
  71
  72 /* Fill in the fpu structure for a core dump.  */
  73 int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
  74 {
  75         memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
  76         return 1;
  77 }
  78
  79 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
  80 {
  81         struct pt_regs *regs = task_pt_regs(tsk);
  82
  83         /* NOTE: usp is error value. */
  84         ELF_CORE_COPY_REGS((*pr_regs), regs)
  85
  86         return 1;
  87 }
  88
  89 #ifndef CONFIG_CPU_PM_NONE
  90 void arch_cpu_idle(void)
  91 {
  92 #ifdef CONFIG_CPU_PM_WAIT
  93         asm volatile("wait\n");
  94 #endif
  95
  96 #ifdef CONFIG_CPU_PM_DOZE
  97         asm volatile("doze\n");
  98 #endif
  99
 100 #ifdef CONFIG_CPU_PM_STOP
 101         asm volatile("stop\n");
 102 #endif
 103 }
 104 #endif