csky/kernel/process.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
0003
0004 #include <linux/module.h>
0005 #include <linux/sched.h>
0006 #include <linux/sched/task_stack.h>
0007 #include <linux/sched/debug.h>
0008 #include <linux/delay.h>
0009 #include <linux/kallsyms.h>
0010 #include <linux/uaccess.h>
0011 #include <linux/ptrace.h>
0012
0013 #include <asm/elf.h>
0014 #include <abi/reg_ops.h>
0015
0016 struct cpuinfo_csky cpu_data[NR_CPUS];
0017
0018 #ifdef CONFIG_STACKPROTECTOR
0019 #include <linux/stackprotector.h>
0020 unsigned long __stack_chk_guard __read_mostly;
0021 EXPORT_SYMBOL(__stack_chk_guard);
0022 #endif
0023
0024 asmlinkage void ret_from_fork(void);
0025 asmlinkage void ret_from_kernel_thread(void);
0026
0027 /*
0028  * Some archs flush debug and FPU info here
0029  */
0030 void flush_thread(void){}
0031
0032 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
0033 {
0034     unsigned long clone_flags = args->flags;
0035     unsigned long usp = args->stack;
0036     unsigned long tls = args->tls;
0037     struct switch_stack *childstack;
0038     struct pt_regs *childregs = task_pt_regs(p);
0039
0040 #ifdef CONFIG_CPU_HAS_FPU
0041     save_to_user_fp(&p->thread.user_fp);
0042 #endif
0043
0044     childstack = ((struct switch_stack *) childregs) - 1;
0045     memset(childstack, 0, sizeof(struct switch_stack));
0046
0047     /* setup thread.sp for switch_to !!! */
0048     p->thread.sp = (unsigned long)childstack;
0049
0050     if (unlikely(args->fn)) {
0051         memset(childregs, 0, sizeof(struct pt_regs));
0052         childstack->r15 = (unsigned long) ret_from_kernel_thread;
0053         childstack->r10 = (unsigned long) args->fn_arg;
0054         childstack->r9 = (unsigned long) args->fn;
0055         childregs->sr = mfcr("psr");
0056     } else {
0057         *childregs = *(current_pt_regs());
0058         if (usp)
0059             childregs->usp = usp;
0060         if (clone_flags & CLONE_SETTLS)
0061             task_thread_info(p)->tp_value = childregs->tls
0062                               = tls;
0063
0064         childregs->a0 = 0;
0065         childstack->r15 = (unsigned long) ret_from_fork;
0066     }
0067
0068     return 0;
0069 }
0070
0071 /* Fill in the fpu structure for a core dump.  */
0072 int dump_fpu(struct pt_regs *regs, struct user_fp *fpu)
0073 {
0074     memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
0075     return 1;
0076 }
0077 EXPORT_SYMBOL(dump_fpu);
0078
0079 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
0080 {
0081     struct pt_regs *regs = task_pt_regs(tsk);
0082
0083     /* NOTE: usp is error value. */
0084     ELF_CORE_COPY_REGS((*pr_regs), regs)
0085
0086     return 1;
0087 }
0088
0089 #ifndef CONFIG_CPU_PM_NONE
0090 void arch_cpu_idle(void)
0091 {
0092 #ifdef CONFIG_CPU_PM_WAIT
0093     asm volatile("wait\n");
0094 #endif
0095
0096 #ifdef CONFIG_CPU_PM_DOZE
0097     asm volatile("doze\n");
0098 #endif
0099
0100 #ifdef CONFIG_CPU_PM_STOP
0101     asm volatile("stop\n");
0102 #endif
0103     raw_local_irq_enable();
0104 }
0105 #endif