// SPDX-License-Identifier: GPL-2.0
|
/*
|
* arch/sh/kernel/process.c
|
*
|
* This file handles the architecture-dependent parts of process handling..
|
*
|
* Copyright (C) 1995 Linus Torvalds
|
*
|
* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
|
* Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
|
* Copyright (C) 2002 - 2008 Paul Mundt
|
*/
|
#include <linux/module.h>
|
#include <linux/mm.h>
|
#include <linux/sched/debug.h>
|
#include <linux/sched/task.h>
|
#include <linux/sched/task_stack.h>
|
#include <linux/slab.h>
|
#include <linux/elfcore.h>
|
#include <linux/fs.h>
|
#include <linux/ftrace.h>
|
#include <linux/hw_breakpoint.h>
|
#include <linux/prefetch.h>
|
#include <linux/stackprotector.h>
|
#include <linux/uaccess.h>
|
#include <asm/mmu_context.h>
|
#include <asm/fpu.h>
|
#include <asm/syscalls.h>
|
#include <asm/switch_to.h>
|
|
void show_regs(struct pt_regs * regs)
|
{
|
pr_info("\n");
|
show_regs_print_info(KERN_DEFAULT);
|
|
pr_info("PC is at %pS\n", (void *)instruction_pointer(regs));
|
pr_info("PR is at %pS\n", (void *)regs->pr);
|
|
pr_info("PC : %08lx SP : %08lx SR : %08lx ", regs->pc,
|
regs->regs[15], regs->sr);
|
#ifdef CONFIG_MMU
|
pr_cont("TEA : %08x\n", __raw_readl(MMU_TEA));
|
#else
|
pr_cont("\n");
|
#endif
|
|
pr_info("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
|
regs->regs[0], regs->regs[1], regs->regs[2], regs->regs[3]);
|
pr_info("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
|
regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]);
|
pr_info("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
|
regs->regs[8], regs->regs[9], regs->regs[10], regs->regs[11]);
|
pr_info("R12 : %08lx R13 : %08lx R14 : %08lx\n",
|
regs->regs[12], regs->regs[13], regs->regs[14]);
|
pr_info("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
|
regs->mach, regs->macl, regs->gbr, regs->pr);
|
|
show_trace(NULL, (unsigned long *)regs->regs[15], regs, KERN_DEFAULT);
|
show_code(regs);
|
}
|
|
void start_thread(struct pt_regs *regs, unsigned long new_pc,
|
unsigned long new_sp)
|
{
|
regs->pr = 0;
|
regs->sr = SR_FD;
|
regs->pc = new_pc;
|
regs->regs[15] = new_sp;
|
|
free_thread_xstate(current);
|
}
|
EXPORT_SYMBOL(start_thread);
|
|
void flush_thread(void)
|
{
|
struct task_struct *tsk = current;
|
|
flush_ptrace_hw_breakpoint(tsk);
|
|
#if defined(CONFIG_SH_FPU)
|
/* Forget lazy FPU state */
|
clear_fpu(tsk, task_pt_regs(tsk));
|
clear_used_math();
|
#endif
|
}
|
|
void release_thread(struct task_struct *dead_task)
|
{
|
/* do nothing */
|
}
|
|
asmlinkage void ret_from_fork(void);
|
asmlinkage void ret_from_kernel_thread(void);
|
|
int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
|
struct task_struct *p, unsigned long tls)
|
{
|
struct thread_info *ti = task_thread_info(p);
|
struct pt_regs *childregs;
|
|
#if defined(CONFIG_SH_DSP)
|
struct task_struct *tsk = current;
|
|
if (is_dsp_enabled(tsk)) {
|
/* We can use the __save_dsp or just copy the struct:
|
* __save_dsp(p);
|
* p->thread.dsp_status.status |= SR_DSP
|
*/
|
p->thread.dsp_status = tsk->thread.dsp_status;
|
}
|
#endif
|
|
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
|
|
childregs = task_pt_regs(p);
|
p->thread.sp = (unsigned long) childregs;
|
if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
|
memset(childregs, 0, sizeof(struct pt_regs));
|
p->thread.pc = (unsigned long) ret_from_kernel_thread;
|
childregs->regs[4] = arg;
|
childregs->regs[5] = usp;
|
childregs->sr = SR_MD;
|
#if defined(CONFIG_SH_FPU)
|
childregs->sr |= SR_FD;
|
#endif
|
ti->addr_limit = KERNEL_DS;
|
ti->status &= ~TS_USEDFPU;
|
p->thread.fpu_counter = 0;
|
return 0;
|
}
|
*childregs = *current_pt_regs();
|
|
if (usp)
|
childregs->regs[15] = usp;
|
ti->addr_limit = USER_DS;
|
|
if (clone_flags & CLONE_SETTLS)
|
childregs->gbr = tls;
|
|
childregs->regs[0] = 0; /* Set return value for child */
|
p->thread.pc = (unsigned long) ret_from_fork;
|
return 0;
|
}
|
|
/*
|
* switch_to(x,y) should switch tasks from x to y.
|
*
|
*/
|
__notrace_funcgraph struct task_struct *
|
__switch_to(struct task_struct *prev, struct task_struct *next)
|
{
|
struct thread_struct *next_t = &next->thread;
|
|
#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
|
__stack_chk_guard = next->stack_canary;
|
#endif
|
|
unlazy_fpu(prev, task_pt_regs(prev));
|
|
/* we're going to use this soon, after a few expensive things */
|
if (next->thread.fpu_counter > 5)
|
prefetch(next_t->xstate);
|
|
#ifdef CONFIG_MMU
|
/*
|
* Restore the kernel mode register
|
* k7 (r7_bank1)
|
*/
|
asm volatile("ldc %0, r7_bank"
|
: /* no output */
|
: "r" (task_thread_info(next)));
|
#endif
|
|
/*
|
* If the task has used fpu the last 5 timeslices, just do a full
|
* restore of the math state immediately to avoid the trap; the
|
* chances of needing FPU soon are obviously high now
|
*/
|
if (next->thread.fpu_counter > 5)
|
__fpu_state_restore();
|
|
return prev;
|
}
|
|
unsigned long get_wchan(struct task_struct *p)
|
{
|
unsigned long pc;
|
|
if (!p || p == current || p->state == TASK_RUNNING)
|
return 0;
|
|
/*
|
* The same comment as on the Alpha applies here, too ...
|
*/
|
pc = thread_saved_pc(p);
|
|
#ifdef CONFIG_FRAME_POINTER
|
if (in_sched_functions(pc)) {
|
unsigned long schedule_frame = (unsigned long)p->thread.sp;
|
return ((unsigned long *)schedule_frame)[21];
|
}
|
#endif
|
|
return pc;
|
}
|
