286 lines
7.2 KiB
C
286 lines
7.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/arch/m68k/kernel/process.c
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*
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* Copyright (C) 1995 Hamish Macdonald
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*
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* 68060 fixes by Jesper Skov
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*/
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/*
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* This file handles the architecture-dependent parts of process handling..
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*/
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task.h>
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#include <linux/sched/task_stack.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/smp.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/ptrace.h>
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#include <linux/user.h>
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#include <linux/reboot.h>
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#include <linux/init_task.h>
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#include <linux/mqueue.h>
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#include <linux/rcupdate.h>
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#include <linux/syscalls.h>
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#include <linux/uaccess.h>
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#include <asm/traps.h>
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#include <asm/machdep.h>
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#include <asm/setup.h>
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asmlinkage void ret_from_fork(void);
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asmlinkage void ret_from_kernel_thread(void);
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void arch_cpu_idle(void)
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{
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#if defined(MACH_ATARI_ONLY)
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/* block out HSYNC on the atari (falcon) */
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__asm__("stop #0x2200" : : : "cc");
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#else
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__asm__("stop #0x2000" : : : "cc");
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#endif
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}
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void machine_restart(char * __unused)
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{
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if (mach_reset)
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mach_reset();
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for (;;);
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}
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void machine_halt(void)
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{
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if (mach_halt)
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mach_halt();
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for (;;);
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}
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void machine_power_off(void)
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{
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do_kernel_power_off();
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for (;;);
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}
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void (*pm_power_off)(void);
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EXPORT_SYMBOL(pm_power_off);
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void show_regs(struct pt_regs * regs)
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{
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pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
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regs->format, regs->vector, regs->pc, regs->sr,
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print_tainted());
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pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
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regs->orig_d0, regs->d0, regs->a2, regs->a1);
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pr_info("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5,
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regs->d4);
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pr_info("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2,
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regs->d1);
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if (!(regs->sr & PS_S))
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pr_info("USP: %08lx\n", rdusp());
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}
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void flush_thread(void)
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{
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current->thread.fc = USER_DATA;
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#ifdef CONFIG_FPU
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if (!FPU_IS_EMU) {
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unsigned long zero = 0;
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asm volatile("frestore %0": :"m" (zero));
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}
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#endif
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}
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/*
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* Why not generic sys_clone, you ask? m68k passes all arguments on stack.
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* And we need all registers saved, which means a bunch of stuff pushed
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* on top of pt_regs, which means that sys_clone() arguments would be
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* buried. We could, of course, copy them, but it's too costly for no
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* good reason - generic clone() would have to copy them *again* for
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* kernel_clone() anyway. So in this case it's actually better to pass pt_regs *
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* and extract arguments for kernel_clone() from there. Eventually we might
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* go for calling kernel_clone() directly from the wrapper, but only after we
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* are finished with kernel_clone() prototype conversion.
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*/
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asmlinkage int m68k_clone(struct pt_regs *regs)
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{
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/* regs will be equal to current_pt_regs() */
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struct kernel_clone_args args = {
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.flags = regs->d1 & ~CSIGNAL,
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.pidfd = (int __user *)regs->d3,
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.child_tid = (int __user *)regs->d4,
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.parent_tid = (int __user *)regs->d3,
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.exit_signal = regs->d1 & CSIGNAL,
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.stack = regs->d2,
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.tls = regs->d5,
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};
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return kernel_clone(&args);
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}
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/*
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* Because extra registers are saved on the stack after the sys_clone3()
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* arguments, this C wrapper extracts them from pt_regs * and then calls the
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* generic sys_clone3() implementation.
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*/
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asmlinkage int m68k_clone3(struct pt_regs *regs)
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{
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return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);
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}
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int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
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{
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unsigned long clone_flags = args->flags;
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unsigned long usp = args->stack;
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unsigned long tls = args->tls;
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struct fork_frame {
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struct switch_stack sw;
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struct pt_regs regs;
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} *frame;
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frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
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p->thread.ksp = (unsigned long)frame;
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p->thread.esp0 = (unsigned long)&frame->regs;
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/*
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* Must save the current SFC/DFC value, NOT the value when
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* the parent was last descheduled - RGH 10-08-96
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*/
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p->thread.fc = USER_DATA;
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if (unlikely(args->fn)) {
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/* kernel thread */
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memset(frame, 0, sizeof(struct fork_frame));
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frame->regs.sr = PS_S;
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frame->sw.a3 = (unsigned long)args->fn;
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frame->sw.d7 = (unsigned long)args->fn_arg;
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frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
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p->thread.usp = 0;
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return 0;
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}
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memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
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sizeof(struct fork_frame));
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frame->regs.d0 = 0;
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frame->sw.retpc = (unsigned long)ret_from_fork;
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p->thread.usp = usp ?: rdusp();
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if (clone_flags & CLONE_SETTLS)
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task_thread_info(p)->tp_value = tls;
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#ifdef CONFIG_FPU
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if (!FPU_IS_EMU) {
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/* Copy the current fpu state */
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asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
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if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
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if (CPU_IS_COLDFIRE) {
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asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
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"fmovel %/fpiar,%1\n\t"
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"fmovel %/fpcr,%2\n\t"
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"fmovel %/fpsr,%3"
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:
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: "m" (p->thread.fp[0]),
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"m" (p->thread.fpcntl[0]),
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"m" (p->thread.fpcntl[1]),
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"m" (p->thread.fpcntl[2])
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: "memory");
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} else {
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asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
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"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
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:
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: "m" (p->thread.fp[0]),
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"m" (p->thread.fpcntl[0])
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: "memory");
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}
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}
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/* Restore the state in case the fpu was busy */
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asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
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}
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#endif /* CONFIG_FPU */
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return 0;
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}
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/* Fill in the fpu structure for a core dump. */
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int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
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{
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if (FPU_IS_EMU) {
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int i;
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memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
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memcpy(fpu->fpregs, current->thread.fp, 96);
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/* Convert internal fpu reg representation
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* into long double format
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*/
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for (i = 0; i < 24; i += 3)
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fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
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((fpu->fpregs[i] & 0x0000ffff) << 16);
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return 1;
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}
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if (IS_ENABLED(CONFIG_FPU)) {
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char fpustate[216];
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/* First dump the fpu context to avoid protocol violation. */
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asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
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if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
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return 0;
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if (CPU_IS_COLDFIRE) {
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asm volatile ("fmovel %/fpiar,%0\n\t"
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"fmovel %/fpcr,%1\n\t"
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"fmovel %/fpsr,%2\n\t"
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"fmovemd %/fp0-%/fp7,%3"
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:
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: "m" (fpu->fpcntl[0]),
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"m" (fpu->fpcntl[1]),
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"m" (fpu->fpcntl[2]),
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"m" (fpu->fpregs[0])
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: "memory");
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} else {
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asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
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:
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: "m" (fpu->fpcntl[0])
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: "memory");
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asm volatile ("fmovemx %/fp0-%/fp7,%0"
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:
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: "m" (fpu->fpregs[0])
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: "memory");
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}
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}
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return 1;
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}
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EXPORT_SYMBOL(dump_fpu);
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unsigned long __get_wchan(struct task_struct *p)
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{
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unsigned long fp, pc;
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unsigned long stack_page;
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int count = 0;
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stack_page = (unsigned long)task_stack_page(p);
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fp = ((struct switch_stack *)p->thread.ksp)->a6;
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do {
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if (fp < stack_page+sizeof(struct thread_info) ||
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fp >= 8184+stack_page)
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return 0;
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pc = ((unsigned long *)fp)[1];
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if (!in_sched_functions(pc))
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return pc;
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fp = *(unsigned long *) fp;
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} while (count++ < 16);
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return 0;
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}
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