| 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 | |