kernel_optimize_test/arch/csky/kernel/process.c
Guo Ren 0ea2dc7cd6 csky: stacktrace supported.
The gcc option "-mbacktrace" will push fp(r8),lr into stack and we could
unwind the stack with:
	fp = *fp
	lr = (unsigned int *)fp[1]

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
2018-12-31 23:12:22 +08:00

142 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/module.h>
#include <linux/version.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/sched/debug.h>
#include <linux/delay.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/ptrace.h>
#include <asm/elf.h>
#include <abi/reg_ops.h>
struct cpuinfo_csky cpu_data[NR_CPUS];
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
/*
* Some archs flush debug and FPU info here
*/
void flush_thread(void){}
/*
* Return saved PC from a blocked thread
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
return sw->r15;
}
int copy_thread(unsigned long clone_flags,
unsigned long usp,
unsigned long kthread_arg,
struct task_struct *p)
{
struct switch_stack *childstack;
struct pt_regs *childregs = task_pt_regs(p);
#ifdef CONFIG_CPU_HAS_FPU
save_to_user_fp(&p->thread.user_fp);
#endif
childstack = ((struct switch_stack *) childregs) - 1;
memset(childstack, 0, sizeof(struct switch_stack));
/* setup ksp for switch_to !!! */
p->thread.ksp = (unsigned long)childstack;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
childstack->r15 = (unsigned long) ret_from_kernel_thread;
childstack->r8 = kthread_arg;
childstack->r9 = usp;
childregs->sr = mfcr("psr");
} else {
*childregs = *(current_pt_regs());
if (usp)
childregs->usp = usp;
if (clone_flags & CLONE_SETTLS)
task_thread_info(p)->tp_value = childregs->tls
= childregs->regs[0];
childregs->a0 = 0;
childstack->r15 = (unsigned long) ret_from_fork;
}
return 0;
}
/* Fill in the fpu structure for a core dump. */
int dump_fpu(struct pt_regs *regs, struct user_fp *fpu)
{
memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
return 1;
}
EXPORT_SYMBOL(dump_fpu);
int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
{
struct pt_regs *regs = task_pt_regs(tsk);
/* NOTE: usp is error value. */
ELF_CORE_COPY_REGS((*pr_regs), regs)
return 1;
}
unsigned long get_wchan(struct task_struct *p)
{
unsigned long lr;
unsigned long *fp, *stack_start, *stack_end;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_start = (unsigned long *)end_of_stack(p);
stack_end = (unsigned long *)(task_stack_page(p) + THREAD_SIZE);
fp = (unsigned long *) thread_saved_fp(p);
do {
if (fp < stack_start || fp > stack_end)
return 0;
#ifdef CONFIG_STACKTRACE
lr = fp[1];
fp = (unsigned long *)fp[0];
#else
lr = *fp++;
#endif
if (!in_sched_functions(lr) &&
__kernel_text_address(lr))
return lr;
} while (count++ < 16);
return 0;
}
EXPORT_SYMBOL(get_wchan);
#ifndef CONFIG_CPU_PM_NONE
void arch_cpu_idle(void)
{
#ifdef CONFIG_CPU_PM_WAIT
asm volatile("wait\n");
#endif
#ifdef CONFIG_CPU_PM_DOZE
asm volatile("doze\n");
#endif
#ifdef CONFIG_CPU_PM_STOP
asm volatile("stop\n");
#endif
local_irq_enable();
}
#endif