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/sched/debug.h> 18 #include <linux/sched/task.h> 19 #include <linux/sched/task_stack.h> 20 #include <linux/kernel.h> 21 #include <linux/mm.h> 22 #include <linux/stddef.h> 23 #include <linux/ptrace.h> 24 #include <linux/user.h> 25 #include <linux/smp.h> 26 #include <linux/reboot.h> 27 #include <linux/delay.h> 28 #include <linux/pm.h> 29 #include <linux/slab.h> 30 #include <linux/cpu.h> 31 32 #include <asm/auxio.h> 33 #include <asm/oplib.h> 34 #include <linux/uaccess.h> 35 #include <asm/page.h> 36 #include <asm/pgalloc.h> 37 #include <asm/pgtable.h> 38 #include <asm/delay.h> 39 #include <asm/processor.h> 40 #include <asm/psr.h> 41 #include <asm/elf.h> 42 #include <asm/prom.h> 43 #include <asm/unistd.h> 44 #include <asm/setup.h> 45 46 #include "kernel.h" 47 48 /* 49 * Power management idle function 50 * Set in pm platform drivers (apc.c and pmc.c) 51 */ 52 void (*sparc_idle)(void); 53 54 /* 55 * Power-off handler instantiation for pm.h compliance 56 * This is done via auxio, but could be used as a fallback 57 * handler when auxio is not present-- unused for now... 58 */ 59 void (*pm_power_off)(void) = machine_power_off; 60 EXPORT_SYMBOL(pm_power_off); 61 62 /* 63 * sysctl - toggle power-off restriction for serial console 64 * systems in machine_power_off() 65 */ 66 int scons_pwroff = 1; 67 68 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); 69 70 struct task_struct *last_task_used_math = NULL; 71 struct thread_info *current_set[NR_CPUS]; 72 73 /* Idle loop support. */ 74 void arch_cpu_idle(void) 75 { 76 if (sparc_idle) 77 (*sparc_idle)(); 78 local_irq_enable(); 79 } 80 81 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 82 void machine_halt(void) 83 { 84 local_irq_enable(); 85 mdelay(8); 86 local_irq_disable(); 87 prom_halt(); 88 panic("Halt failed!"); 89 } 90 91 void machine_restart(char * cmd) 92 { 93 char *p; 94 95 local_irq_enable(); 96 mdelay(8); 97 local_irq_disable(); 98 99 p = strchr (reboot_command, '\n'); 100 if (p) *p = 0; 101 if (cmd) 102 prom_reboot(cmd); 103 if (*reboot_command) 104 prom_reboot(reboot_command); 105 prom_feval ("reset"); 106 panic("Reboot failed!"); 107 } 108 109 void machine_power_off(void) 110 { 111 if (auxio_power_register && 112 (strcmp(of_console_device->type, "serial") || scons_pwroff)) { 113 u8 power_register = sbus_readb(auxio_power_register); 114 power_register |= AUXIO_POWER_OFF; 115 sbus_writeb(power_register, auxio_power_register); 116 } 117 118 machine_halt(); 119 } 120 121 void show_regs(struct pt_regs *r) 122 { 123 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; 124 125 show_regs_print_info(KERN_DEFAULT); 126 127 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 128 r->psr, r->pc, r->npc, r->y, print_tainted()); 129 printk("PC: <%pS>\n", (void *) r->pc); 130 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 131 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 132 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 133 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 134 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 135 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 136 printk("RPC: <%pS>\n", (void *) r->u_regs[15]); 137 138 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 139 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 140 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 141 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 142 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 143 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 144 } 145 146 /* 147 * The show_stack is an external API which we do not use ourselves. 148 * The oops is printed in die_if_kernel. 149 */ 150 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 151 { 152 unsigned long pc, fp; 153 unsigned long task_base; 154 struct reg_window32 *rw; 155 int count = 0; 156 157 if (!tsk) 158 tsk = current; 159 160 if (tsk == current && !_ksp) 161 __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp)); 162 163 task_base = (unsigned long) task_stack_page(tsk); 164 fp = (unsigned long) _ksp; 165 do { 166 /* Bogus frame pointer? */ 167 if (fp < (task_base + sizeof(struct thread_info)) || 168 fp >= (task_base + (PAGE_SIZE << 1))) 169 break; 170 rw = (struct reg_window32 *) fp; 171 pc = rw->ins[7]; 172 printk("[%08lx : ", pc); 173 printk("%pS ] ", (void *) pc); 174 fp = rw->ins[6]; 175 } while (++count < 16); 176 printk("\n"); 177 } 178 179 /* 180 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 181 */ 182 unsigned long thread_saved_pc(struct task_struct *tsk) 183 { 184 return task_thread_info(tsk)->kpc; 185 } 186 187 /* 188 * Free current thread data structures etc.. 189 */ 190 void exit_thread(struct task_struct *tsk) 191 { 192 #ifndef CONFIG_SMP 193 if (last_task_used_math == tsk) { 194 #else 195 if (test_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU)) { 196 #endif 197 /* Keep process from leaving FPU in a bogon state. */ 198 put_psr(get_psr() | PSR_EF); 199 fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr, 200 &tsk->thread.fpqueue[0], &tsk->thread.fpqdepth); 201 #ifndef CONFIG_SMP 202 last_task_used_math = NULL; 203 #else 204 clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU); 205 #endif 206 } 207 } 208 209 void flush_thread(void) 210 { 211 current_thread_info()->w_saved = 0; 212 213 #ifndef CONFIG_SMP 214 if(last_task_used_math == current) { 215 #else 216 if (test_thread_flag(TIF_USEDFPU)) { 217 #endif 218 /* Clean the fpu. */ 219 put_psr(get_psr() | PSR_EF); 220 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 221 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 222 #ifndef CONFIG_SMP 223 last_task_used_math = NULL; 224 #else 225 clear_thread_flag(TIF_USEDFPU); 226 #endif 227 } 228 229 /* This task is no longer a kernel thread. */ 230 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 231 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 232 233 /* We must fixup kregs as well. */ 234 /* XXX This was not fixed for ti for a while, worked. Unused? */ 235 current->thread.kregs = (struct pt_regs *) 236 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 237 } 238 } 239 240 static inline struct sparc_stackf __user * 241 clone_stackframe(struct sparc_stackf __user *dst, 242 struct sparc_stackf __user *src) 243 { 244 unsigned long size, fp; 245 struct sparc_stackf *tmp; 246 struct sparc_stackf __user *sp; 247 248 if (get_user(tmp, &src->fp)) 249 return NULL; 250 251 fp = (unsigned long) tmp; 252 size = (fp - ((unsigned long) src)); 253 fp = (unsigned long) dst; 254 sp = (struct sparc_stackf __user *)(fp - size); 255 256 /* do_fork() grabs the parent semaphore, we must release it 257 * temporarily so we can build the child clone stack frame 258 * without deadlocking. 259 */ 260 if (__copy_user(sp, src, size)) 261 sp = NULL; 262 else if (put_user(fp, &sp->fp)) 263 sp = NULL; 264 265 return sp; 266 } 267 268 asmlinkage int sparc_do_fork(unsigned long clone_flags, 269 unsigned long stack_start, 270 struct pt_regs *regs, 271 unsigned long stack_size) 272 { 273 unsigned long parent_tid_ptr, child_tid_ptr; 274 unsigned long orig_i1 = regs->u_regs[UREG_I1]; 275 long ret; 276 277 parent_tid_ptr = regs->u_regs[UREG_I2]; 278 child_tid_ptr = regs->u_regs[UREG_I4]; 279 280 ret = do_fork(clone_flags, stack_start, stack_size, 281 (int __user *) parent_tid_ptr, 282 (int __user *) child_tid_ptr); 283 284 /* If we get an error and potentially restart the system 285 * call, we're screwed because copy_thread() clobbered 286 * the parent's %o1. So detect that case and restore it 287 * here. 288 */ 289 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) 290 regs->u_regs[UREG_I1] = orig_i1; 291 292 return ret; 293 } 294 295 /* Copy a Sparc thread. The fork() return value conventions 296 * under SunOS are nothing short of bletcherous: 297 * Parent --> %o0 == childs pid, %o1 == 0 298 * Child --> %o0 == parents pid, %o1 == 1 299 * 300 * NOTE: We have a separate fork kpsr/kwim because 301 * the parent could change these values between 302 * sys_fork invocation and when we reach here 303 * if the parent should sleep while trying to 304 * allocate the task_struct and kernel stack in 305 * do_fork(). 306 * XXX See comment above sys_vfork in sparc64. todo. 307 */ 308 extern void ret_from_fork(void); 309 extern void ret_from_kernel_thread(void); 310 311 int copy_thread(unsigned long clone_flags, unsigned long sp, 312 unsigned long arg, struct task_struct *p) 313 { 314 struct thread_info *ti = task_thread_info(p); 315 struct pt_regs *childregs, *regs = current_pt_regs(); 316 char *new_stack; 317 318 #ifndef CONFIG_SMP 319 if(last_task_used_math == current) { 320 #else 321 if (test_thread_flag(TIF_USEDFPU)) { 322 #endif 323 put_psr(get_psr() | PSR_EF); 324 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 325 &p->thread.fpqueue[0], &p->thread.fpqdepth); 326 } 327 328 /* 329 * p->thread_info new_stack childregs stack bottom 330 * ! ! ! ! 331 * V V (stk.fr.) V (pt_regs) V 332 * +----- - - - - - ------+===========+=============+ 333 */ 334 new_stack = task_stack_page(p) + THREAD_SIZE; 335 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 336 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 337 338 /* 339 * A new process must start with interrupts disabled, see schedule_tail() 340 * and finish_task_switch(). (If we do not do it and if a timer interrupt 341 * hits before we unlock and attempts to take the rq->lock, we deadlock.) 342 * 343 * Thus, kpsr |= PSR_PIL. 344 */ 345 ti->ksp = (unsigned long) new_stack; 346 p->thread.kregs = childregs; 347 348 if (unlikely(p->flags & PF_KTHREAD)) { 349 extern int nwindows; 350 unsigned long psr; 351 memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); 352 p->thread.flags |= SPARC_FLAG_KTHREAD; 353 p->thread.current_ds = KERNEL_DS; 354 ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); 355 childregs->u_regs[UREG_G1] = sp; /* function */ 356 childregs->u_regs[UREG_G2] = arg; 357 psr = childregs->psr = get_psr(); 358 ti->kpsr = psr | PSR_PIL; 359 ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows); 360 return 0; 361 } 362 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 363 childregs->u_regs[UREG_FP] = sp; 364 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 365 p->thread.current_ds = USER_DS; 366 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 367 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 368 ti->kwim = current->thread.fork_kwim; 369 370 if (sp != regs->u_regs[UREG_FP]) { 371 struct sparc_stackf __user *childstack; 372 struct sparc_stackf __user *parentstack; 373 374 /* 375 * This is a clone() call with supplied user stack. 376 * Set some valid stack frames to give to the child. 377 */ 378 childstack = (struct sparc_stackf __user *) 379 (sp & ~0xfUL); 380 parentstack = (struct sparc_stackf __user *) 381 regs->u_regs[UREG_FP]; 382 383 #if 0 384 printk("clone: parent stack:\n"); 385 show_stackframe(parentstack); 386 #endif 387 388 childstack = clone_stackframe(childstack, parentstack); 389 if (!childstack) 390 return -EFAULT; 391 392 #if 0 393 printk("clone: child stack:\n"); 394 show_stackframe(childstack); 395 #endif 396 397 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 398 } 399 400 #ifdef CONFIG_SMP 401 /* FPU must be disabled on SMP. */ 402 childregs->psr &= ~PSR_EF; 403 clear_tsk_thread_flag(p, TIF_USEDFPU); 404 #endif 405 406 /* Set the return value for the child. */ 407 childregs->u_regs[UREG_I0] = current->pid; 408 childregs->u_regs[UREG_I1] = 1; 409 410 /* Set the return value for the parent. */ 411 regs->u_regs[UREG_I1] = 0; 412 413 if (clone_flags & CLONE_SETTLS) 414 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 415 416 return 0; 417 } 418 419 /* 420 * fill in the fpu structure for a core dump. 421 */ 422 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 423 { 424 if (used_math()) { 425 memset(fpregs, 0, sizeof(*fpregs)); 426 fpregs->pr_q_entrysize = 8; 427 return 1; 428 } 429 #ifdef CONFIG_SMP 430 if (test_thread_flag(TIF_USEDFPU)) { 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 clear_thread_flag(TIF_USEDFPU); 437 } 438 } 439 #else 440 if (current == last_task_used_math) { 441 put_psr(get_psr() | PSR_EF); 442 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 443 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 444 if (regs != NULL) { 445 regs->psr &= ~(PSR_EF); 446 last_task_used_math = NULL; 447 } 448 } 449 #endif 450 memcpy(&fpregs->pr_fr.pr_regs[0], 451 ¤t->thread.float_regs[0], 452 (sizeof(unsigned long) * 32)); 453 fpregs->pr_fsr = current->thread.fsr; 454 fpregs->pr_qcnt = current->thread.fpqdepth; 455 fpregs->pr_q_entrysize = 8; 456 fpregs->pr_en = 1; 457 if(fpregs->pr_qcnt != 0) { 458 memcpy(&fpregs->pr_q[0], 459 ¤t->thread.fpqueue[0], 460 sizeof(struct fpq) * fpregs->pr_qcnt); 461 } 462 /* Zero out the rest. */ 463 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 464 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 465 return 1; 466 } 467 468 unsigned long get_wchan(struct task_struct *task) 469 { 470 unsigned long pc, fp, bias = 0; 471 unsigned long task_base = (unsigned long) task; 472 unsigned long ret = 0; 473 struct reg_window32 *rw; 474 int count = 0; 475 476 if (!task || task == current || 477 task->state == TASK_RUNNING) 478 goto out; 479 480 fp = task_thread_info(task)->ksp + bias; 481 do { 482 /* Bogus frame pointer? */ 483 if (fp < (task_base + sizeof(struct thread_info)) || 484 fp >= (task_base + (2 * PAGE_SIZE))) 485 break; 486 rw = (struct reg_window32 *) fp; 487 pc = rw->ins[7]; 488 if (!in_sched_functions(pc)) { 489 ret = pc; 490 goto out; 491 } 492 fp = rw->ins[6] + bias; 493 } while (++count < 16); 494 495 out: 496 return ret; 497 } 498 499