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