// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/m68k/kernel/process.c
*
* Copyright (C) 1995 Hamish Macdonald
*
* 68060 fixes by Jesper Skov
*/
/*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/reboot.h>
#include <linux/init_task.h>
#include <linux/mqueue.h>
#include <linux/rcupdate.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/elfcore.h>
#include <asm/traps.h>
#include <asm/machdep.h>
#include <asm/setup.h>
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
void arch_cpu_idle(void)
{
#if defined(MACH_ATARI_ONLY)
/* block out HSYNC on the atari (falcon) */
__asm__("stop #0x2200" : : : "cc");
#else
__asm__("stop #0x2000" : : : "cc");
#endif
}
void machine_restart(char * __unused)
{
if (mach_reset)
mach_reset();
for (;;);
}
void machine_halt(void)
{
if (mach_halt)
mach_halt();
for (;;);
}
void machine_power_off(void)
{
do_kernel_power_off();
for (;;);
}
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
void show_regs(struct pt_regs * regs)
{
pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
regs->format, regs->vector, regs->pc, regs->sr,
print_tainted());
pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
regs->orig_d0, regs->d0, regs->a2, regs->a1);
pr_info("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5,
regs->d4);
pr_info("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2,
regs->d1);
if (!(regs->sr & PS_S))
pr_info("USP: %08lx\n", rdusp());
}
void flush_thread(void)
{
current->thread.fc = USER_DATA;
#ifdef CONFIG_FPU
if (!FPU_IS_EMU) {
unsigned long zero = 0;
asm volatile("frestore %0": :"m" (zero));
}
#endif
}
/*
* Why not generic sys_clone, you ask? m68k passes all arguments on stack.
* And we need all registers saved, which means a bunch of stuff pushed
* on top of pt_regs, which means that sys_clone() arguments would be
* buried. We could, of course, copy them, but it's too costly for no
* good reason - generic clone() would have to copy them *again* for
* kernel_clone() anyway. So in this case it's actually better to pass pt_regs *
* and extract arguments for kernel_clone() from there. Eventually we might
* go for calling kernel_clone() directly from the wrapper, but only after we
* are finished with kernel_clone() prototype conversion.
*/
asmlinkage int m68k_clone(struct pt_regs *regs)
{
/* regs will be equal to current_pt_regs() */
struct kernel_clone_args args = {
.flags = regs->d1 & ~CSIGNAL,
.pidfd = (int __user *)regs->d3,
.child_tid = (int __user *)regs->d4,
.parent_tid = (int __user *)regs->d3,
.exit_signal = regs->d1 & CSIGNAL,
.stack = regs->d2,
.tls = regs->d5,
};
return kernel_clone(&args);
}
/*
* Because extra registers are saved on the stack after the sys_clone3()
* arguments, this C wrapper extracts them from pt_regs * and then calls the
* generic sys_clone3() implementation.
*/
asmlinkage int m68k_clone3(struct pt_regs *regs)
{
return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);
}
int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
{
unsigned long clone_flags = args->flags;
unsigned long usp = args->stack;
unsigned long tls = args->tls;
struct fork_frame {
struct switch_stack sw;
struct pt_regs regs;
} *frame;
frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
p->thread.ksp = (unsigned long)frame;
p->thread.esp0 = (unsigned long)&frame->regs;
/*
* Must save the current SFC/DFC value, NOT the value when
* the parent was last descheduled - RGH 10-08-96
*/
p->thread.fc = USER_DATA;
if (unlikely(args->fn)) {
/* kernel thread */
memset(frame, 0, sizeof(struct fork_frame));
frame->regs.sr = PS_S;
frame->sw.a3 = (unsigned long)args->fn;
frame->sw.d7 = (unsigned long)args->fn_arg;
frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
p->thread.usp = 0;
return 0;
}
memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
sizeof(struct fork_frame));
frame->regs.d0 = 0;
frame->sw.retpc = (unsigned long)ret_from_fork;
p->thread.usp = usp ?: rdusp();
if (clone_flags & CLONE_SETTLS)
task_thread_info(p)->tp_value = tls;
#ifdef CONFIG_FPU
if (!FPU_IS_EMU) {
/* Copy the current fpu state */
asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
if (CPU_IS_COLDFIRE) {
asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
"fmovel %/fpiar,%1\n\t"
"fmovel %/fpcr,%2\n\t"
"fmovel %/fpsr,%3"
:
: "m" (p->thread.fp[0]),
"m" (p->thread.fpcntl[0]),
"m" (p->thread.fpcntl[1]),
"m" (p->thread.fpcntl[2])
: "memory");
} else {
asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
:
: "m" (p->thread.fp[0]),
"m" (p->thread.fpcntl[0])
: "memory");
}
}
/* Restore the state in case the fpu was busy */
asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
}
#endif /* CONFIG_FPU */
return 0;
}
/* Fill in the fpu structure for a core dump. */
int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
{
if (FPU_IS_EMU) {
int i;
memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
memcpy(fpu->fpregs, current->thread.fp, 96);
/* Convert internal fpu reg representation
* into long double format
*/
for (i = 0; i < 24; i += 3)
fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
((fpu->fpregs[i] & 0x0000ffff) << 16);
return 1;
}
if (IS_ENABLED(CONFIG_FPU)) {
char fpustate[216];
/* First dump the fpu context to avoid protocol violation. */
asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
return 0;
if (CPU_IS_COLDFIRE) {
asm volatile ("fmovel %/fpiar,%0\n\t"
"fmovel %/fpcr,%1\n\t"
"fmovel %/fpsr,%2\n\t"
"fmovemd %/fp0-%/fp7,%3"
:
: "m" (fpu->fpcntl[0]),
"m" (fpu->fpcntl[1]),
"m" (fpu->fpcntl[2]),
"m" (fpu->fpregs[0])
: "memory");
} else {
asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
:
: "m" (fpu->fpcntl[0])
: "memory");
asm volatile ("fmovemx %/fp0-%/fp7,%0"
:
: "m" (fpu->fpregs[0])
: "memory");
}
}
return 1;
}
unsigned long __get_wchan(struct task_struct *p)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
stack_page = (unsigned long)task_stack_page(p);
fp = ((struct switch_stack *)p->thread.ksp)->a6;
do {
if (fp < stack_page+sizeof(struct thread_info) ||
fp >= 8184+stack_page)
return 0;
pc = ((unsigned long *)fp)[1];
if (!in_sched_functions(pc))
return pc;
fp = *(unsigned long *) fp;
} while (count++ < 16);
return 0;
}