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/elfcore.h> 14 #include <linux/errno.h> 15 #include <linux/module.h> 16 #include <linux/sched.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/stddef.h> 20 #include <linux/ptrace.h> 21 #include <linux/user.h> 22 #include <linux/smp.h> 23 #include <linux/reboot.h> 24 #include <linux/delay.h> 25 #include <linux/pm.h> 26 #include <linux/slab.h> 27 #include <linux/cpu.h> 28 29 #include <asm/auxio.h> 30 #include <asm/oplib.h> 31 #include <asm/uaccess.h> 32 #include <asm/page.h> 33 #include <asm/pgalloc.h> 34 #include <asm/pgtable.h> 35 #include <asm/delay.h> 36 #include <asm/processor.h> 37 #include <asm/psr.h> 38 #include <asm/elf.h> 39 #include <asm/prom.h> 40 #include <asm/unistd.h> 41 #include <asm/setup.h> 42 43 #include "kernel.h" 44 45 /* 46 * Power management idle function 47 * Set in pm platform drivers (apc.c and pmc.c) 48 */ 49 void (*sparc_idle)(void); 50 51 /* 52 * Power-off handler instantiation for pm.h compliance 53 * This is done via auxio, but could be used as a fallback 54 * handler when auxio is not present-- unused for now... 55 */ 56 void (*pm_power_off)(void) = machine_power_off; 57 EXPORT_SYMBOL(pm_power_off); 58 59 /* 60 * sysctl - toggle power-off restriction for serial console 61 * systems in machine_power_off() 62 */ 63 int scons_pwroff = 1; 64 65 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); 66 67 struct task_struct *last_task_used_math = NULL; 68 struct thread_info *current_set[NR_CPUS]; 69 70 /* Idle loop support. */ 71 void arch_cpu_idle(void) 72 { 73 if (sparc_idle) 74 (*sparc_idle)(); 75 local_irq_enable(); 76 } 77 78 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 79 void machine_halt(void) 80 { 81 local_irq_enable(); 82 mdelay(8); 83 local_irq_disable(); 84 prom_halt(); 85 panic("Halt failed!"); 86 } 87 88 void machine_restart(char * cmd) 89 { 90 char *p; 91 92 local_irq_enable(); 93 mdelay(8); 94 local_irq_disable(); 95 96 p = strchr (reboot_command, '\n'); 97 if (p) *p = 0; 98 if (cmd) 99 prom_reboot(cmd); 100 if (*reboot_command) 101 prom_reboot(reboot_command); 102 prom_feval ("reset"); 103 panic("Reboot failed!"); 104 } 105 106 void machine_power_off(void) 107 { 108 if (auxio_power_register && 109 (strcmp(of_console_device->type, "serial") || scons_pwroff)) { 110 u8 power_register = sbus_readb(auxio_power_register); 111 power_register |= AUXIO_POWER_OFF; 112 sbus_writeb(power_register, auxio_power_register); 113 } 114 115 machine_halt(); 116 } 117 118 void show_regs(struct pt_regs *r) 119 { 120 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; 121 122 show_regs_print_info(KERN_DEFAULT); 123 124 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 125 r->psr, r->pc, r->npc, r->y, print_tainted()); 126 printk("PC: <%pS>\n", (void *) r->pc); 127 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 128 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 129 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 130 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 131 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 132 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 133 printk("RPC: <%pS>\n", (void *) r->u_regs[15]); 134 135 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 136 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 137 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 138 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 139 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 140 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 141 } 142 143 /* 144 * The show_stack is an external API which we do not use ourselves. 145 * The oops is printed in die_if_kernel. 146 */ 147 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 148 { 149 unsigned long pc, fp; 150 unsigned long task_base; 151 struct reg_window32 *rw; 152 int count = 0; 153 154 if (!tsk) 155 tsk = current; 156 157 if (tsk == current && !_ksp) 158 __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp)); 159 160 task_base = (unsigned long) task_stack_page(tsk); 161 fp = (unsigned long) _ksp; 162 do { 163 /* Bogus frame pointer? */ 164 if (fp < (task_base + sizeof(struct thread_info)) || 165 fp >= (task_base + (PAGE_SIZE << 1))) 166 break; 167 rw = (struct reg_window32 *) fp; 168 pc = rw->ins[7]; 169 printk("[%08lx : ", pc); 170 printk("%pS ] ", (void *) pc); 171 fp = rw->ins[6]; 172 } while (++count < 16); 173 printk("\n"); 174 } 175 176 /* 177 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 178 */ 179 unsigned long thread_saved_pc(struct task_struct *tsk) 180 { 181 return task_thread_info(tsk)->kpc; 182 } 183 184 /* 185 * Free current thread data structures etc.. 186 */ 187 void exit_thread(void) 188 { 189 #ifndef CONFIG_SMP 190 if(last_task_used_math == current) { 191 #else 192 if (test_thread_flag(TIF_USEDFPU)) { 193 #endif 194 /* Keep process from leaving FPU in a bogon state. */ 195 put_psr(get_psr() | PSR_EF); 196 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 197 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 198 #ifndef CONFIG_SMP 199 last_task_used_math = NULL; 200 #else 201 clear_thread_flag(TIF_USEDFPU); 202 #endif 203 } 204 } 205 206 void flush_thread(void) 207 { 208 current_thread_info()->w_saved = 0; 209 210 #ifndef CONFIG_SMP 211 if(last_task_used_math == current) { 212 #else 213 if (test_thread_flag(TIF_USEDFPU)) { 214 #endif 215 /* Clean the fpu. */ 216 put_psr(get_psr() | PSR_EF); 217 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 218 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 219 #ifndef CONFIG_SMP 220 last_task_used_math = NULL; 221 #else 222 clear_thread_flag(TIF_USEDFPU); 223 #endif 224 } 225 226 /* This task is no longer a kernel thread. */ 227 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 228 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 229 230 /* We must fixup kregs as well. */ 231 /* XXX This was not fixed for ti for a while, worked. Unused? */ 232 current->thread.kregs = (struct pt_regs *) 233 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 234 } 235 } 236 237 static inline struct sparc_stackf __user * 238 clone_stackframe(struct sparc_stackf __user *dst, 239 struct sparc_stackf __user *src) 240 { 241 unsigned long size, fp; 242 struct sparc_stackf *tmp; 243 struct sparc_stackf __user *sp; 244 245 if (get_user(tmp, &src->fp)) 246 return NULL; 247 248 fp = (unsigned long) tmp; 249 size = (fp - ((unsigned long) src)); 250 fp = (unsigned long) dst; 251 sp = (struct sparc_stackf __user *)(fp - size); 252 253 /* do_fork() grabs the parent semaphore, we must release it 254 * temporarily so we can build the child clone stack frame 255 * without deadlocking. 256 */ 257 if (__copy_user(sp, src, size)) 258 sp = NULL; 259 else if (put_user(fp, &sp->fp)) 260 sp = NULL; 261 262 return sp; 263 } 264 265 asmlinkage int sparc_do_fork(unsigned long clone_flags, 266 unsigned long stack_start, 267 struct pt_regs *regs, 268 unsigned long stack_size) 269 { 270 unsigned long parent_tid_ptr, child_tid_ptr; 271 unsigned long orig_i1 = regs->u_regs[UREG_I1]; 272 long ret; 273 274 parent_tid_ptr = regs->u_regs[UREG_I2]; 275 child_tid_ptr = regs->u_regs[UREG_I4]; 276 277 ret = do_fork(clone_flags, stack_start, stack_size, 278 (int __user *) parent_tid_ptr, 279 (int __user *) child_tid_ptr); 280 281 /* If we get an error and potentially restart the system 282 * call, we're screwed because copy_thread() clobbered 283 * the parent's %o1. So detect that case and restore it 284 * here. 285 */ 286 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) 287 regs->u_regs[UREG_I1] = orig_i1; 288 289 return ret; 290 } 291 292 /* Copy a Sparc thread. The fork() return value conventions 293 * under SunOS are nothing short of bletcherous: 294 * Parent --> %o0 == childs pid, %o1 == 0 295 * Child --> %o0 == parents pid, %o1 == 1 296 * 297 * NOTE: We have a separate fork kpsr/kwim because 298 * the parent could change these values between 299 * sys_fork invocation and when we reach here 300 * if the parent should sleep while trying to 301 * allocate the task_struct and kernel stack in 302 * do_fork(). 303 * XXX See comment above sys_vfork in sparc64. todo. 304 */ 305 extern void ret_from_fork(void); 306 extern void ret_from_kernel_thread(void); 307 308 int copy_thread(unsigned long clone_flags, unsigned long sp, 309 unsigned long arg, struct task_struct *p) 310 { 311 struct thread_info *ti = task_thread_info(p); 312 struct pt_regs *childregs, *regs = current_pt_regs(); 313 char *new_stack; 314 315 #ifndef CONFIG_SMP 316 if(last_task_used_math == current) { 317 #else 318 if (test_thread_flag(TIF_USEDFPU)) { 319 #endif 320 put_psr(get_psr() | PSR_EF); 321 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 322 &p->thread.fpqueue[0], &p->thread.fpqdepth); 323 } 324 325 /* 326 * p->thread_info new_stack childregs stack bottom 327 * ! ! ! ! 328 * V V (stk.fr.) V (pt_regs) V 329 * +----- - - - - - ------+===========+=============+ 330 */ 331 new_stack = task_stack_page(p) + THREAD_SIZE; 332 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 333 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 334 335 /* 336 * A new process must start with interrupts closed in 2.5, 337 * because this is how Mingo's scheduler works (see schedule_tail 338 * and finish_arch_switch). If we do not do it, a timer interrupt hits 339 * before we unlock, attempts to re-take the rq->lock, and then we die. 340 * Thus, kpsr|=PSR_PIL. 341 */ 342 ti->ksp = (unsigned long) new_stack; 343 p->thread.kregs = childregs; 344 345 if (unlikely(p->flags & PF_KTHREAD)) { 346 extern int nwindows; 347 unsigned long psr; 348 memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); 349 p->thread.flags |= SPARC_FLAG_KTHREAD; 350 p->thread.current_ds = KERNEL_DS; 351 ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); 352 childregs->u_regs[UREG_G1] = sp; /* function */ 353 childregs->u_regs[UREG_G2] = arg; 354 psr = childregs->psr = get_psr(); 355 ti->kpsr = psr | PSR_PIL; 356 ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows); 357 return 0; 358 } 359 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 360 childregs->u_regs[UREG_FP] = sp; 361 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 362 p->thread.current_ds = USER_DS; 363 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 364 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 365 ti->kwim = current->thread.fork_kwim; 366 367 if (sp != regs->u_regs[UREG_FP]) { 368 struct sparc_stackf __user *childstack; 369 struct sparc_stackf __user *parentstack; 370 371 /* 372 * This is a clone() call with supplied user stack. 373 * Set some valid stack frames to give to the child. 374 */ 375 childstack = (struct sparc_stackf __user *) 376 (sp & ~0xfUL); 377 parentstack = (struct sparc_stackf __user *) 378 regs->u_regs[UREG_FP]; 379 380 #if 0 381 printk("clone: parent stack:\n"); 382 show_stackframe(parentstack); 383 #endif 384 385 childstack = clone_stackframe(childstack, parentstack); 386 if (!childstack) 387 return -EFAULT; 388 389 #if 0 390 printk("clone: child stack:\n"); 391 show_stackframe(childstack); 392 #endif 393 394 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 395 } 396 397 #ifdef CONFIG_SMP 398 /* FPU must be disabled on SMP. */ 399 childregs->psr &= ~PSR_EF; 400 clear_tsk_thread_flag(p, TIF_USEDFPU); 401 #endif 402 403 /* Set the return value for the child. */ 404 childregs->u_regs[UREG_I0] = current->pid; 405 childregs->u_regs[UREG_I1] = 1; 406 407 /* Set the return value for the parent. */ 408 regs->u_regs[UREG_I1] = 0; 409 410 if (clone_flags & CLONE_SETTLS) 411 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 412 413 return 0; 414 } 415 416 /* 417 * fill in the fpu structure for a core dump. 418 */ 419 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 420 { 421 if (used_math()) { 422 memset(fpregs, 0, sizeof(*fpregs)); 423 fpregs->pr_q_entrysize = 8; 424 return 1; 425 } 426 #ifdef CONFIG_SMP 427 if (test_thread_flag(TIF_USEDFPU)) { 428 put_psr(get_psr() | PSR_EF); 429 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 430 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 431 if (regs != NULL) { 432 regs->psr &= ~(PSR_EF); 433 clear_thread_flag(TIF_USEDFPU); 434 } 435 } 436 #else 437 if (current == last_task_used_math) { 438 put_psr(get_psr() | PSR_EF); 439 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 440 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 441 if (regs != NULL) { 442 regs->psr &= ~(PSR_EF); 443 last_task_used_math = NULL; 444 } 445 } 446 #endif 447 memcpy(&fpregs->pr_fr.pr_regs[0], 448 ¤t->thread.float_regs[0], 449 (sizeof(unsigned long) * 32)); 450 fpregs->pr_fsr = current->thread.fsr; 451 fpregs->pr_qcnt = current->thread.fpqdepth; 452 fpregs->pr_q_entrysize = 8; 453 fpregs->pr_en = 1; 454 if(fpregs->pr_qcnt != 0) { 455 memcpy(&fpregs->pr_q[0], 456 ¤t->thread.fpqueue[0], 457 sizeof(struct fpq) * fpregs->pr_qcnt); 458 } 459 /* Zero out the rest. */ 460 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 461 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 462 return 1; 463 } 464 465 unsigned long get_wchan(struct task_struct *task) 466 { 467 unsigned long pc, fp, bias = 0; 468 unsigned long task_base = (unsigned long) task; 469 unsigned long ret = 0; 470 struct reg_window32 *rw; 471 int count = 0; 472 473 if (!task || task == current || 474 task->state == TASK_RUNNING) 475 goto out; 476 477 fp = task_thread_info(task)->ksp + bias; 478 do { 479 /* Bogus frame pointer? */ 480 if (fp < (task_base + sizeof(struct thread_info)) || 481 fp >= (task_base + (2 * PAGE_SIZE))) 482 break; 483 rw = (struct reg_window32 *) fp; 484 pc = rw->ins[7]; 485 if (!in_sched_functions(pc)) { 486 ret = pc; 487 goto out; 488 } 489 fp = rw->ins[6] + bias; 490 } while (++count < 16); 491 492 out: 493 return ret; 494 } 495 496