1 // SPDX-License-Identifier: GPL-2.0
3 * linux/arch/m68k/kernel/process.c
5 * Copyright (C) 1995 Hamish Macdonald
7 * 68060 fixes by Jesper Skov
11 * This file handles the architecture-dependent parts of process handling..
14 #include <linux/errno.h>
15 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <linux/sched/debug.h>
18 #include <linux/sched/task.h>
19 #include <linux/sched/task_stack.h>
20 #include <linux/kernel.h>
22 #include <linux/slab.h>
24 #include <linux/smp.h>
25 #include <linux/stddef.h>
26 #include <linux/unistd.h>
27 #include <linux/ptrace.h>
28 #include <linux/user.h>
29 #include <linux/reboot.h>
30 #include <linux/init_task.h>
31 #include <linux/mqueue.h>
32 #include <linux/rcupdate.h>
33 #include <linux/syscalls.h>
34 #include <linux/uaccess.h>
36 #include <asm/traps.h>
37 #include <asm/machdep.h>
38 #include <asm/setup.h>
39 #include <asm/pgtable.h>
42 asmlinkage void ret_from_fork(void);
43 asmlinkage void ret_from_kernel_thread(void);
45 void arch_cpu_idle(void)
47 #if defined(MACH_ATARI_ONLY)
48 /* block out HSYNC on the atari (falcon) */
49 __asm__("stop #0x2200" : : : "cc");
51 __asm__("stop #0x2000" : : : "cc");
55 void machine_restart(char * __unused)
62 void machine_halt(void)
69 void machine_power_off(void)
76 void (*pm_power_off)(void) = machine_power_off;
77 EXPORT_SYMBOL(pm_power_off);
79 void show_regs(struct pt_regs * regs)
81 pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
82 regs->format, regs->vector, regs->pc, regs->sr,
84 pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
85 regs->orig_d0, regs->d0, regs->a2, regs->a1);
86 pr_info("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5,
88 pr_info("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2,
90 if (!(regs->sr & PS_S))
91 pr_info("USP: %08lx\n", rdusp());
94 void flush_thread(void)
96 current->thread.fs = __USER_DS;
99 unsigned long zero = 0;
100 asm volatile("frestore %0": :"m" (zero));
106 * Why not generic sys_clone, you ask? m68k passes all arguments on stack.
107 * And we need all registers saved, which means a bunch of stuff pushed
108 * on top of pt_regs, which means that sys_clone() arguments would be
109 * buried. We could, of course, copy them, but it's too costly for no
110 * good reason - generic clone() would have to copy them *again* for
111 * _do_fork() anyway. So in this case it's actually better to pass pt_regs *
112 * and extract arguments for _do_fork() from there. Eventually we might
113 * go for calling _do_fork() directly from the wrapper, but only after we
114 * are finished with _do_fork() prototype conversion.
116 asmlinkage int m68k_clone(struct pt_regs *regs)
118 /* regs will be equal to current_pt_regs() */
119 struct kernel_clone_args args = {
120 .flags = regs->d1 & ~CSIGNAL,
121 .pidfd = (int __user *)regs->d3,
122 .child_tid = (int __user *)regs->d4,
123 .parent_tid = (int __user *)regs->d3,
124 .exit_signal = regs->d1 & CSIGNAL,
129 if (!legacy_clone_args_valid(&args))
132 return _do_fork(&args);
136 * Because extra registers are saved on the stack after the sys_clone3()
137 * arguments, this C wrapper extracts them from pt_regs * and then calls the
138 * generic sys_clone3() implementation.
140 asmlinkage int m68k_clone3(struct pt_regs *regs)
142 return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);
145 int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
146 unsigned long arg, struct task_struct *p,
150 struct switch_stack sw;
154 frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
156 p->thread.ksp = (unsigned long)frame;
157 p->thread.esp0 = (unsigned long)&frame->regs;
160 * Must save the current SFC/DFC value, NOT the value when
161 * the parent was last descheduled - RGH 10-08-96
163 p->thread.fs = get_fs().seg;
165 if (unlikely(p->flags & PF_KTHREAD)) {
167 memset(frame, 0, sizeof(struct fork_frame));
168 frame->regs.sr = PS_S;
169 frame->sw.a3 = usp; /* function */
171 frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
175 memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
176 sizeof(struct fork_frame));
178 frame->sw.retpc = (unsigned long)ret_from_fork;
179 p->thread.usp = usp ?: rdusp();
181 if (clone_flags & CLONE_SETTLS)
182 task_thread_info(p)->tp_value = tls;
186 /* Copy the current fpu state */
187 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
189 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
190 if (CPU_IS_COLDFIRE) {
191 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
192 "fmovel %/fpiar,%1\n\t"
193 "fmovel %/fpcr,%2\n\t"
196 : "m" (p->thread.fp[0]),
197 "m" (p->thread.fpcntl[0]),
198 "m" (p->thread.fpcntl[1]),
199 "m" (p->thread.fpcntl[2])
202 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
203 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
205 : "m" (p->thread.fp[0]),
206 "m" (p->thread.fpcntl[0])
211 /* Restore the state in case the fpu was busy */
212 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
214 #endif /* CONFIG_FPU */
219 /* Fill in the fpu structure for a core dump. */
220 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
225 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
226 memcpy(fpu->fpregs, current->thread.fp, 96);
227 /* Convert internal fpu reg representation
228 * into long double format
230 for (i = 0; i < 24; i += 3)
231 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
232 ((fpu->fpregs[i] & 0x0000ffff) << 16);
236 if (IS_ENABLED(CONFIG_FPU)) {
239 /* First dump the fpu context to avoid protocol violation. */
240 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
241 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
244 if (CPU_IS_COLDFIRE) {
245 asm volatile ("fmovel %/fpiar,%0\n\t"
246 "fmovel %/fpcr,%1\n\t"
247 "fmovel %/fpsr,%2\n\t"
248 "fmovemd %/fp0-%/fp7,%3"
250 : "m" (fpu->fpcntl[0]),
251 "m" (fpu->fpcntl[1]),
252 "m" (fpu->fpcntl[2]),
256 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
258 : "m" (fpu->fpcntl[0])
260 asm volatile ("fmovemx %/fp0-%/fp7,%0"
262 : "m" (fpu->fpregs[0])
269 EXPORT_SYMBOL(dump_fpu);
271 unsigned long get_wchan(struct task_struct *p)
273 unsigned long fp, pc;
274 unsigned long stack_page;
276 if (!p || p == current || p->state == TASK_RUNNING)
279 stack_page = (unsigned long)task_stack_page(p);
280 fp = ((struct switch_stack *)p->thread.ksp)->a6;
282 if (fp < stack_page+sizeof(struct thread_info) ||
283 fp >= 8184+stack_page)
285 pc = ((unsigned long *)fp)[1];
286 if (!in_sched_functions(pc))
288 fp = *(unsigned long *) fp;
289 } while (count++ < 16);