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 44 /* 45 * Return saved PC from a blocked thread 46 */ 47 unsigned long thread_saved_pc(struct task_struct *tsk) 48 { 49 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp; 50 /* Check whether the thread is blocked in resume() */ 51 if (in_sched_functions(sw->retpc)) 52 return ((unsigned long *)sw->a6)[1]; 53 else 54 return sw->retpc; 55 } 56 57 void arch_cpu_idle(void) 58 { 59 #if defined(MACH_ATARI_ONLY) 60 /* block out HSYNC on the atari (falcon) */ 61 __asm__("stop #0x2200" : : : "cc"); 62 #else 63 __asm__("stop #0x2000" : : : "cc"); 64 #endif 65 } 66 67 void machine_restart(char * __unused) 68 { 69 if (mach_reset) 70 mach_reset(); 71 for (;;); 72 } 73 74 void machine_halt(void) 75 { 76 if (mach_halt) 77 mach_halt(); 78 for (;;); 79 } 80 81 void machine_power_off(void) 82 { 83 if (mach_power_off) 84 mach_power_off(); 85 for (;;); 86 } 87 88 void (*pm_power_off)(void) = machine_power_off; 89 EXPORT_SYMBOL(pm_power_off); 90 91 void show_regs(struct pt_regs * regs) 92 { 93 pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 94 regs->format, regs->vector, regs->pc, regs->sr, 95 print_tainted()); 96 pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 97 regs->orig_d0, regs->d0, regs->a2, regs->a1); 98 pr_info("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5, 99 regs->d4); 100 pr_info("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2, 101 regs->d1); 102 if (!(regs->sr & PS_S)) 103 pr_info("USP: %08lx\n", rdusp()); 104 } 105 106 void flush_thread(void) 107 { 108 current->thread.fs = __USER_DS; 109 #ifdef CONFIG_FPU 110 if (!FPU_IS_EMU) { 111 unsigned long zero = 0; 112 asm volatile("frestore %0": :"m" (zero)); 113 } 114 #endif 115 } 116 117 /* 118 * Why not generic sys_clone, you ask? m68k passes all arguments on stack. 119 * And we need all registers saved, which means a bunch of stuff pushed 120 * on top of pt_regs, which means that sys_clone() arguments would be 121 * buried. We could, of course, copy them, but it's too costly for no 122 * good reason - generic clone() would have to copy them *again* for 123 * do_fork() anyway. So in this case it's actually better to pass pt_regs * 124 * and extract arguments for do_fork() from there. Eventually we might 125 * go for calling do_fork() directly from the wrapper, but only after we 126 * are finished with do_fork() prototype conversion. 127 */ 128 asmlinkage int m68k_clone(struct pt_regs *regs) 129 { 130 /* regs will be equal to current_pt_regs() */ 131 return do_fork(regs->d1, regs->d2, 0, 132 (int __user *)regs->d3, (int __user *)regs->d4); 133 } 134 135 int copy_thread(unsigned long clone_flags, unsigned long usp, 136 unsigned long arg, struct task_struct *p) 137 { 138 struct fork_frame { 139 struct switch_stack sw; 140 struct pt_regs regs; 141 } *frame; 142 143 frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1; 144 145 p->thread.ksp = (unsigned long)frame; 146 p->thread.esp0 = (unsigned long)&frame->regs; 147 148 /* 149 * Must save the current SFC/DFC value, NOT the value when 150 * the parent was last descheduled - RGH 10-08-96 151 */ 152 p->thread.fs = get_fs().seg; 153 154 if (unlikely(p->flags & PF_KTHREAD)) { 155 /* kernel thread */ 156 memset(frame, 0, sizeof(struct fork_frame)); 157 frame->regs.sr = PS_S; 158 frame->sw.a3 = usp; /* function */ 159 frame->sw.d7 = arg; 160 frame->sw.retpc = (unsigned long)ret_from_kernel_thread; 161 p->thread.usp = 0; 162 return 0; 163 } 164 memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs), 165 sizeof(struct fork_frame)); 166 frame->regs.d0 = 0; 167 frame->sw.retpc = (unsigned long)ret_from_fork; 168 p->thread.usp = usp ?: rdusp(); 169 170 if (clone_flags & CLONE_SETTLS) 171 task_thread_info(p)->tp_value = frame->regs.d5; 172 173 #ifdef CONFIG_FPU 174 if (!FPU_IS_EMU) { 175 /* Copy the current fpu state */ 176 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); 177 178 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) { 179 if (CPU_IS_COLDFIRE) { 180 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t" 181 "fmovel %/fpiar,%1\n\t" 182 "fmovel %/fpcr,%2\n\t" 183 "fmovel %/fpsr,%3" 184 : 185 : "m" (p->thread.fp[0]), 186 "m" (p->thread.fpcntl[0]), 187 "m" (p->thread.fpcntl[1]), 188 "m" (p->thread.fpcntl[2]) 189 : "memory"); 190 } else { 191 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" 192 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" 193 : 194 : "m" (p->thread.fp[0]), 195 "m" (p->thread.fpcntl[0]) 196 : "memory"); 197 } 198 } 199 200 /* Restore the state in case the fpu was busy */ 201 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); 202 } 203 #endif /* CONFIG_FPU */ 204 205 return 0; 206 } 207 208 /* Fill in the fpu structure for a core dump. */ 209 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) 210 { 211 if (FPU_IS_EMU) { 212 int i; 213 214 memcpy(fpu->fpcntl, current->thread.fpcntl, 12); 215 memcpy(fpu->fpregs, current->thread.fp, 96); 216 /* Convert internal fpu reg representation 217 * into long double format 218 */ 219 for (i = 0; i < 24; i += 3) 220 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | 221 ((fpu->fpregs[i] & 0x0000ffff) << 16); 222 return 1; 223 } 224 225 if (IS_ENABLED(CONFIG_FPU)) { 226 char fpustate[216]; 227 228 /* First dump the fpu context to avoid protocol violation. */ 229 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); 230 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) 231 return 0; 232 233 if (CPU_IS_COLDFIRE) { 234 asm volatile ("fmovel %/fpiar,%0\n\t" 235 "fmovel %/fpcr,%1\n\t" 236 "fmovel %/fpsr,%2\n\t" 237 "fmovemd %/fp0-%/fp7,%3" 238 : 239 : "m" (fpu->fpcntl[0]), 240 "m" (fpu->fpcntl[1]), 241 "m" (fpu->fpcntl[2]), 242 "m" (fpu->fpregs[0]) 243 : "memory"); 244 } else { 245 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" 246 : 247 : "m" (fpu->fpcntl[0]) 248 : "memory"); 249 asm volatile ("fmovemx %/fp0-%/fp7,%0" 250 : 251 : "m" (fpu->fpregs[0]) 252 : "memory"); 253 } 254 } 255 256 return 1; 257 } 258 EXPORT_SYMBOL(dump_fpu); 259 260 unsigned long get_wchan(struct task_struct *p) 261 { 262 unsigned long fp, pc; 263 unsigned long stack_page; 264 int count = 0; 265 if (!p || p == current || p->state == TASK_RUNNING) 266 return 0; 267 268 stack_page = (unsigned long)task_stack_page(p); 269 fp = ((struct switch_stack *)p->thread.ksp)->a6; 270 do { 271 if (fp < stack_page+sizeof(struct thread_info) || 272 fp >= 8184+stack_page) 273 return 0; 274 pc = ((unsigned long *)fp)[1]; 275 if (!in_sched_functions(pc)) 276 return pc; 277 fp = *(unsigned long *) fp; 278 } while (count++ < 16); 279 return 0; 280 } 281