1 /* 2 * linux/arch/m68k/kernel/process.c 3 * 4 * Copyright (C) 1995 Hamish Macdonald 5 * 6 * 68060 fixes by Jesper Skov 7 */ 8 9 /* 10 * This file handles the architecture-dependent parts of process handling.. 11 */ 12 13 #include <linux/errno.h> 14 #include <linux/module.h> 15 #include <linux/sched.h> 16 #include <linux/sched/debug.h> 17 #include <linux/sched/task.h> 18 #include <linux/sched/task_stack.h> 19 #include <linux/kernel.h> 20 #include <linux/mm.h> 21 #include <linux/slab.h> 22 #include <linux/fs.h> 23 #include <linux/smp.h> 24 #include <linux/stddef.h> 25 #include <linux/unistd.h> 26 #include <linux/ptrace.h> 27 #include <linux/user.h> 28 #include <linux/reboot.h> 29 #include <linux/init_task.h> 30 #include <linux/mqueue.h> 31 #include <linux/rcupdate.h> 32 33 #include <linux/uaccess.h> 34 #include <asm/traps.h> 35 #include <asm/machdep.h> 36 #include <asm/setup.h> 37 #include <asm/pgtable.h> 38 39 40 asmlinkage void ret_from_fork(void); 41 asmlinkage void ret_from_kernel_thread(void); 42 43 void arch_cpu_idle(void) 44 { 45 #if defined(MACH_ATARI_ONLY) 46 /* block out HSYNC on the atari (falcon) */ 47 __asm__("stop #0x2200" : : : "cc"); 48 #else 49 __asm__("stop #0x2000" : : : "cc"); 50 #endif 51 } 52 53 void machine_restart(char * __unused) 54 { 55 if (mach_reset) 56 mach_reset(); 57 for (;;); 58 } 59 60 void machine_halt(void) 61 { 62 if (mach_halt) 63 mach_halt(); 64 for (;;); 65 } 66 67 void machine_power_off(void) 68 { 69 if (mach_power_off) 70 mach_power_off(); 71 for (;;); 72 } 73 74 void (*pm_power_off)(void) = machine_power_off; 75 EXPORT_SYMBOL(pm_power_off); 76 77 void show_regs(struct pt_regs * regs) 78 { 79 pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 80 regs->format, regs->vector, regs->pc, regs->sr, 81 print_tainted()); 82 pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 83 regs->orig_d0, regs->d0, regs->a2, regs->a1); 84 pr_info("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5, 85 regs->d4); 86 pr_info("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2, 87 regs->d1); 88 if (!(regs->sr & PS_S)) 89 pr_info("USP: %08lx\n", rdusp()); 90 } 91 92 void flush_thread(void) 93 { 94 current->thread.fs = __USER_DS; 95 #ifdef CONFIG_FPU 96 if (!FPU_IS_EMU) { 97 unsigned long zero = 0; 98 asm volatile("frestore %0": :"m" (zero)); 99 } 100 #endif 101 } 102 103 /* 104 * Why not generic sys_clone, you ask? m68k passes all arguments on stack. 105 * And we need all registers saved, which means a bunch of stuff pushed 106 * on top of pt_regs, which means that sys_clone() arguments would be 107 * buried. We could, of course, copy them, but it's too costly for no 108 * good reason - generic clone() would have to copy them *again* for 109 * do_fork() anyway. So in this case it's actually better to pass pt_regs * 110 * and extract arguments for do_fork() from there. Eventually we might 111 * go for calling do_fork() directly from the wrapper, but only after we 112 * are finished with do_fork() prototype conversion. 113 */ 114 asmlinkage int m68k_clone(struct pt_regs *regs) 115 { 116 /* regs will be equal to current_pt_regs() */ 117 return do_fork(regs->d1, regs->d2, 0, 118 (int __user *)regs->d3, (int __user *)regs->d4); 119 } 120 121 int copy_thread(unsigned long clone_flags, unsigned long usp, 122 unsigned long arg, struct task_struct *p) 123 { 124 struct fork_frame { 125 struct switch_stack sw; 126 struct pt_regs regs; 127 } *frame; 128 129 frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1; 130 131 p->thread.ksp = (unsigned long)frame; 132 p->thread.esp0 = (unsigned long)&frame->regs; 133 134 /* 135 * Must save the current SFC/DFC value, NOT the value when 136 * the parent was last descheduled - RGH 10-08-96 137 */ 138 p->thread.fs = get_fs().seg; 139 140 if (unlikely(p->flags & PF_KTHREAD)) { 141 /* kernel thread */ 142 memset(frame, 0, sizeof(struct fork_frame)); 143 frame->regs.sr = PS_S; 144 frame->sw.a3 = usp; /* function */ 145 frame->sw.d7 = arg; 146 frame->sw.retpc = (unsigned long)ret_from_kernel_thread; 147 p->thread.usp = 0; 148 return 0; 149 } 150 memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs), 151 sizeof(struct fork_frame)); 152 frame->regs.d0 = 0; 153 frame->sw.retpc = (unsigned long)ret_from_fork; 154 p->thread.usp = usp ?: rdusp(); 155 156 if (clone_flags & CLONE_SETTLS) 157 task_thread_info(p)->tp_value = frame->regs.d5; 158 159 #ifdef CONFIG_FPU 160 if (!FPU_IS_EMU) { 161 /* Copy the current fpu state */ 162 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); 163 164 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) { 165 if (CPU_IS_COLDFIRE) { 166 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t" 167 "fmovel %/fpiar,%1\n\t" 168 "fmovel %/fpcr,%2\n\t" 169 "fmovel %/fpsr,%3" 170 : 171 : "m" (p->thread.fp[0]), 172 "m" (p->thread.fpcntl[0]), 173 "m" (p->thread.fpcntl[1]), 174 "m" (p->thread.fpcntl[2]) 175 : "memory"); 176 } else { 177 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" 178 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" 179 : 180 : "m" (p->thread.fp[0]), 181 "m" (p->thread.fpcntl[0]) 182 : "memory"); 183 } 184 } 185 186 /* Restore the state in case the fpu was busy */ 187 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); 188 } 189 #endif /* CONFIG_FPU */ 190 191 return 0; 192 } 193 194 /* Fill in the fpu structure for a core dump. */ 195 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) 196 { 197 if (FPU_IS_EMU) { 198 int i; 199 200 memcpy(fpu->fpcntl, current->thread.fpcntl, 12); 201 memcpy(fpu->fpregs, current->thread.fp, 96); 202 /* Convert internal fpu reg representation 203 * into long double format 204 */ 205 for (i = 0; i < 24; i += 3) 206 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | 207 ((fpu->fpregs[i] & 0x0000ffff) << 16); 208 return 1; 209 } 210 211 if (IS_ENABLED(CONFIG_FPU)) { 212 char fpustate[216]; 213 214 /* First dump the fpu context to avoid protocol violation. */ 215 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); 216 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) 217 return 0; 218 219 if (CPU_IS_COLDFIRE) { 220 asm volatile ("fmovel %/fpiar,%0\n\t" 221 "fmovel %/fpcr,%1\n\t" 222 "fmovel %/fpsr,%2\n\t" 223 "fmovemd %/fp0-%/fp7,%3" 224 : 225 : "m" (fpu->fpcntl[0]), 226 "m" (fpu->fpcntl[1]), 227 "m" (fpu->fpcntl[2]), 228 "m" (fpu->fpregs[0]) 229 : "memory"); 230 } else { 231 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" 232 : 233 : "m" (fpu->fpcntl[0]) 234 : "memory"); 235 asm volatile ("fmovemx %/fp0-%/fp7,%0" 236 : 237 : "m" (fpu->fpregs[0]) 238 : "memory"); 239 } 240 } 241 242 return 1; 243 } 244 EXPORT_SYMBOL(dump_fpu); 245 246 unsigned long get_wchan(struct task_struct *p) 247 { 248 unsigned long fp, pc; 249 unsigned long stack_page; 250 int count = 0; 251 if (!p || p == current || p->state == TASK_RUNNING) 252 return 0; 253 254 stack_page = (unsigned long)task_stack_page(p); 255 fp = ((struct switch_stack *)p->thread.ksp)->a6; 256 do { 257 if (fp < stack_page+sizeof(struct thread_info) || 258 fp >= 8184+stack_page) 259 return 0; 260 pc = ((unsigned long *)fp)[1]; 261 if (!in_sched_functions(pc)) 262 return pc; 263 fp = *(unsigned long *) fp; 264 } while (count++ < 16); 265 return 0; 266 } 267