1 /* linux/arch/sparc/kernel/process.c 2 * 3 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net) 4 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) 5 */ 6 7 /* 8 * This file handles the architecture-dependent parts of process handling.. 9 */ 10 11 #include <stdarg.h> 12 13 #include <linux/errno.h> 14 #include <linux/module.h> 15 #include <linux/sched.h> 16 #include <linux/kernel.h> 17 #include <linux/mm.h> 18 #include <linux/stddef.h> 19 #include <linux/ptrace.h> 20 #include <linux/user.h> 21 #include <linux/smp.h> 22 #include <linux/reboot.h> 23 #include <linux/delay.h> 24 #include <linux/pm.h> 25 #include <linux/init.h> 26 #include <linux/slab.h> 27 28 #include <asm/auxio.h> 29 #include <asm/oplib.h> 30 #include <asm/uaccess.h> 31 #include <asm/page.h> 32 #include <asm/pgalloc.h> 33 #include <asm/pgtable.h> 34 #include <asm/delay.h> 35 #include <asm/processor.h> 36 #include <asm/psr.h> 37 #include <asm/elf.h> 38 #include <asm/prom.h> 39 #include <asm/unistd.h> 40 #include <asm/setup.h> 41 42 /* 43 * Power management idle function 44 * Set in pm platform drivers (apc.c and pmc.c) 45 */ 46 void (*sparc_idle)(void); 47 48 /* 49 * Power-off handler instantiation for pm.h compliance 50 * This is done via auxio, but could be used as a fallback 51 * handler when auxio is not present-- unused for now... 52 */ 53 void (*pm_power_off)(void) = machine_power_off; 54 EXPORT_SYMBOL(pm_power_off); 55 56 /* 57 * sysctl - toggle power-off restriction for serial console 58 * systems in machine_power_off() 59 */ 60 int scons_pwroff = 1; 61 62 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); 63 64 struct task_struct *last_task_used_math = NULL; 65 struct thread_info *current_set[NR_CPUS]; 66 67 /* Idle loop support. */ 68 void arch_cpu_idle(void) 69 { 70 if (sparc_idle) 71 (*sparc_idle)(); 72 local_irq_enable(); 73 } 74 75 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 76 void machine_halt(void) 77 { 78 local_irq_enable(); 79 mdelay(8); 80 local_irq_disable(); 81 prom_halt(); 82 panic("Halt failed!"); 83 } 84 85 void machine_restart(char * cmd) 86 { 87 char *p; 88 89 local_irq_enable(); 90 mdelay(8); 91 local_irq_disable(); 92 93 p = strchr (reboot_command, '\n'); 94 if (p) *p = 0; 95 if (cmd) 96 prom_reboot(cmd); 97 if (*reboot_command) 98 prom_reboot(reboot_command); 99 prom_feval ("reset"); 100 panic("Reboot failed!"); 101 } 102 103 void machine_power_off(void) 104 { 105 if (auxio_power_register && 106 (strcmp(of_console_device->type, "serial") || scons_pwroff)) 107 *auxio_power_register |= AUXIO_POWER_OFF; 108 machine_halt(); 109 } 110 111 void show_regs(struct pt_regs *r) 112 { 113 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; 114 115 show_regs_print_info(KERN_DEFAULT); 116 117 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 118 r->psr, r->pc, r->npc, r->y, print_tainted()); 119 printk("PC: <%pS>\n", (void *) r->pc); 120 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 121 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 122 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 123 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 124 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 125 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 126 printk("RPC: <%pS>\n", (void *) r->u_regs[15]); 127 128 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 129 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 130 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 131 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 132 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 133 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 134 } 135 136 /* 137 * The show_stack is an external API which we do not use ourselves. 138 * The oops is printed in die_if_kernel. 139 */ 140 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 141 { 142 unsigned long pc, fp; 143 unsigned long task_base; 144 struct reg_window32 *rw; 145 int count = 0; 146 147 if (!tsk) 148 tsk = current; 149 150 if (tsk == current && !_ksp) 151 __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp)); 152 153 task_base = (unsigned long) task_stack_page(tsk); 154 fp = (unsigned long) _ksp; 155 do { 156 /* Bogus frame pointer? */ 157 if (fp < (task_base + sizeof(struct thread_info)) || 158 fp >= (task_base + (PAGE_SIZE << 1))) 159 break; 160 rw = (struct reg_window32 *) fp; 161 pc = rw->ins[7]; 162 printk("[%08lx : ", pc); 163 printk("%pS ] ", (void *) pc); 164 fp = rw->ins[6]; 165 } while (++count < 16); 166 printk("\n"); 167 } 168 169 /* 170 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 171 */ 172 unsigned long thread_saved_pc(struct task_struct *tsk) 173 { 174 return task_thread_info(tsk)->kpc; 175 } 176 177 /* 178 * Free current thread data structures etc.. 179 */ 180 void exit_thread(void) 181 { 182 #ifndef CONFIG_SMP 183 if(last_task_used_math == current) { 184 #else 185 if (test_thread_flag(TIF_USEDFPU)) { 186 #endif 187 /* Keep process from leaving FPU in a bogon state. */ 188 put_psr(get_psr() | PSR_EF); 189 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 190 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 191 #ifndef CONFIG_SMP 192 last_task_used_math = NULL; 193 #else 194 clear_thread_flag(TIF_USEDFPU); 195 #endif 196 } 197 } 198 199 void flush_thread(void) 200 { 201 current_thread_info()->w_saved = 0; 202 203 #ifndef CONFIG_SMP 204 if(last_task_used_math == current) { 205 #else 206 if (test_thread_flag(TIF_USEDFPU)) { 207 #endif 208 /* Clean the fpu. */ 209 put_psr(get_psr() | PSR_EF); 210 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 211 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 212 #ifndef CONFIG_SMP 213 last_task_used_math = NULL; 214 #else 215 clear_thread_flag(TIF_USEDFPU); 216 #endif 217 } 218 219 /* This task is no longer a kernel thread. */ 220 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 221 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 222 223 /* We must fixup kregs as well. */ 224 /* XXX This was not fixed for ti for a while, worked. Unused? */ 225 current->thread.kregs = (struct pt_regs *) 226 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 227 } 228 } 229 230 static inline struct sparc_stackf __user * 231 clone_stackframe(struct sparc_stackf __user *dst, 232 struct sparc_stackf __user *src) 233 { 234 unsigned long size, fp; 235 struct sparc_stackf *tmp; 236 struct sparc_stackf __user *sp; 237 238 if (get_user(tmp, &src->fp)) 239 return NULL; 240 241 fp = (unsigned long) tmp; 242 size = (fp - ((unsigned long) src)); 243 fp = (unsigned long) dst; 244 sp = (struct sparc_stackf __user *)(fp - size); 245 246 /* do_fork() grabs the parent semaphore, we must release it 247 * temporarily so we can build the child clone stack frame 248 * without deadlocking. 249 */ 250 if (__copy_user(sp, src, size)) 251 sp = NULL; 252 else if (put_user(fp, &sp->fp)) 253 sp = NULL; 254 255 return sp; 256 } 257 258 asmlinkage int sparc_do_fork(unsigned long clone_flags, 259 unsigned long stack_start, 260 struct pt_regs *regs, 261 unsigned long stack_size) 262 { 263 unsigned long parent_tid_ptr, child_tid_ptr; 264 unsigned long orig_i1 = regs->u_regs[UREG_I1]; 265 long ret; 266 267 parent_tid_ptr = regs->u_regs[UREG_I2]; 268 child_tid_ptr = regs->u_regs[UREG_I4]; 269 270 ret = do_fork(clone_flags, stack_start, stack_size, 271 (int __user *) parent_tid_ptr, 272 (int __user *) child_tid_ptr); 273 274 /* If we get an error and potentially restart the system 275 * call, we're screwed because copy_thread() clobbered 276 * the parent's %o1. So detect that case and restore it 277 * here. 278 */ 279 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) 280 regs->u_regs[UREG_I1] = orig_i1; 281 282 return ret; 283 } 284 285 /* Copy a Sparc thread. The fork() return value conventions 286 * under SunOS are nothing short of bletcherous: 287 * Parent --> %o0 == childs pid, %o1 == 0 288 * Child --> %o0 == parents pid, %o1 == 1 289 * 290 * NOTE: We have a separate fork kpsr/kwim because 291 * the parent could change these values between 292 * sys_fork invocation and when we reach here 293 * if the parent should sleep while trying to 294 * allocate the task_struct and kernel stack in 295 * do_fork(). 296 * XXX See comment above sys_vfork in sparc64. todo. 297 */ 298 extern void ret_from_fork(void); 299 extern void ret_from_kernel_thread(void); 300 301 int copy_thread(unsigned long clone_flags, unsigned long sp, 302 unsigned long arg, struct task_struct *p) 303 { 304 struct thread_info *ti = task_thread_info(p); 305 struct pt_regs *childregs, *regs = current_pt_regs(); 306 char *new_stack; 307 308 #ifndef CONFIG_SMP 309 if(last_task_used_math == current) { 310 #else 311 if (test_thread_flag(TIF_USEDFPU)) { 312 #endif 313 put_psr(get_psr() | PSR_EF); 314 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 315 &p->thread.fpqueue[0], &p->thread.fpqdepth); 316 } 317 318 /* 319 * p->thread_info new_stack childregs stack bottom 320 * ! ! ! ! 321 * V V (stk.fr.) V (pt_regs) V 322 * +----- - - - - - ------+===========+=============+ 323 */ 324 new_stack = task_stack_page(p) + THREAD_SIZE; 325 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 326 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 327 328 /* 329 * A new process must start with interrupts closed in 2.5, 330 * because this is how Mingo's scheduler works (see schedule_tail 331 * and finish_arch_switch). If we do not do it, a timer interrupt hits 332 * before we unlock, attempts to re-take the rq->lock, and then we die. 333 * Thus, kpsr|=PSR_PIL. 334 */ 335 ti->ksp = (unsigned long) new_stack; 336 p->thread.kregs = childregs; 337 338 if (unlikely(p->flags & PF_KTHREAD)) { 339 extern int nwindows; 340 unsigned long psr; 341 memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); 342 p->thread.flags |= SPARC_FLAG_KTHREAD; 343 p->thread.current_ds = KERNEL_DS; 344 ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); 345 childregs->u_regs[UREG_G1] = sp; /* function */ 346 childregs->u_regs[UREG_G2] = arg; 347 psr = childregs->psr = get_psr(); 348 ti->kpsr = psr | PSR_PIL; 349 ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows); 350 return 0; 351 } 352 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 353 childregs->u_regs[UREG_FP] = sp; 354 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 355 p->thread.current_ds = USER_DS; 356 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 357 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 358 ti->kwim = current->thread.fork_kwim; 359 360 if (sp != regs->u_regs[UREG_FP]) { 361 struct sparc_stackf __user *childstack; 362 struct sparc_stackf __user *parentstack; 363 364 /* 365 * This is a clone() call with supplied user stack. 366 * Set some valid stack frames to give to the child. 367 */ 368 childstack = (struct sparc_stackf __user *) 369 (sp & ~0xfUL); 370 parentstack = (struct sparc_stackf __user *) 371 regs->u_regs[UREG_FP]; 372 373 #if 0 374 printk("clone: parent stack:\n"); 375 show_stackframe(parentstack); 376 #endif 377 378 childstack = clone_stackframe(childstack, parentstack); 379 if (!childstack) 380 return -EFAULT; 381 382 #if 0 383 printk("clone: child stack:\n"); 384 show_stackframe(childstack); 385 #endif 386 387 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 388 } 389 390 #ifdef CONFIG_SMP 391 /* FPU must be disabled on SMP. */ 392 childregs->psr &= ~PSR_EF; 393 clear_tsk_thread_flag(p, TIF_USEDFPU); 394 #endif 395 396 /* Set the return value for the child. */ 397 childregs->u_regs[UREG_I0] = current->pid; 398 childregs->u_regs[UREG_I1] = 1; 399 400 /* Set the return value for the parent. */ 401 regs->u_regs[UREG_I1] = 0; 402 403 if (clone_flags & CLONE_SETTLS) 404 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 405 406 return 0; 407 } 408 409 /* 410 * fill in the fpu structure for a core dump. 411 */ 412 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 413 { 414 if (used_math()) { 415 memset(fpregs, 0, sizeof(*fpregs)); 416 fpregs->pr_q_entrysize = 8; 417 return 1; 418 } 419 #ifdef CONFIG_SMP 420 if (test_thread_flag(TIF_USEDFPU)) { 421 put_psr(get_psr() | PSR_EF); 422 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 423 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 424 if (regs != NULL) { 425 regs->psr &= ~(PSR_EF); 426 clear_thread_flag(TIF_USEDFPU); 427 } 428 } 429 #else 430 if (current == last_task_used_math) { 431 put_psr(get_psr() | PSR_EF); 432 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 433 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 434 if (regs != NULL) { 435 regs->psr &= ~(PSR_EF); 436 last_task_used_math = NULL; 437 } 438 } 439 #endif 440 memcpy(&fpregs->pr_fr.pr_regs[0], 441 ¤t->thread.float_regs[0], 442 (sizeof(unsigned long) * 32)); 443 fpregs->pr_fsr = current->thread.fsr; 444 fpregs->pr_qcnt = current->thread.fpqdepth; 445 fpregs->pr_q_entrysize = 8; 446 fpregs->pr_en = 1; 447 if(fpregs->pr_qcnt != 0) { 448 memcpy(&fpregs->pr_q[0], 449 ¤t->thread.fpqueue[0], 450 sizeof(struct fpq) * fpregs->pr_qcnt); 451 } 452 /* Zero out the rest. */ 453 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 454 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 455 return 1; 456 } 457 458 unsigned long get_wchan(struct task_struct *task) 459 { 460 unsigned long pc, fp, bias = 0; 461 unsigned long task_base = (unsigned long) task; 462 unsigned long ret = 0; 463 struct reg_window32 *rw; 464 int count = 0; 465 466 if (!task || task == current || 467 task->state == TASK_RUNNING) 468 goto out; 469 470 fp = task_thread_info(task)->ksp + bias; 471 do { 472 /* Bogus frame pointer? */ 473 if (fp < (task_base + sizeof(struct thread_info)) || 474 fp >= (task_base + (2 * PAGE_SIZE))) 475 break; 476 rw = (struct reg_window32 *) fp; 477 pc = rw->ins[7]; 478 if (!in_sched_functions(pc)) { 479 ret = pc; 480 goto out; 481 } 482 fp = rw->ins[6] + bias; 483 } while (++count < 16); 484 485 out: 486 return ret; 487 } 488 489