1 // SPDX-License-Identifier: GPL-2.0 2 /* linux/arch/sparc/kernel/process.c 3 * 4 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net) 5 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) 6 */ 7 8 /* 9 * This file handles the architecture-dependent parts of process handling.. 10 */ 11 12 #include <stdarg.h> 13 14 #include <linux/elfcore.h> 15 #include <linux/errno.h> 16 #include <linux/module.h> 17 #include <linux/sched.h> 18 #include <linux/sched/debug.h> 19 #include <linux/sched/task.h> 20 #include <linux/sched/task_stack.h> 21 #include <linux/kernel.h> 22 #include <linux/mm.h> 23 #include <linux/stddef.h> 24 #include <linux/ptrace.h> 25 #include <linux/user.h> 26 #include <linux/smp.h> 27 #include <linux/reboot.h> 28 #include <linux/delay.h> 29 #include <linux/pm.h> 30 #include <linux/slab.h> 31 #include <linux/cpu.h> 32 33 #include <asm/auxio.h> 34 #include <asm/oplib.h> 35 #include <linux/uaccess.h> 36 #include <asm/page.h> 37 #include <asm/pgalloc.h> 38 #include <asm/pgtable.h> 39 #include <asm/delay.h> 40 #include <asm/processor.h> 41 #include <asm/psr.h> 42 #include <asm/elf.h> 43 #include <asm/prom.h> 44 #include <asm/unistd.h> 45 #include <asm/setup.h> 46 47 #include "kernel.h" 48 49 /* 50 * Power management idle function 51 * Set in pm platform drivers (apc.c and pmc.c) 52 */ 53 void (*sparc_idle)(void); 54 55 /* 56 * Power-off handler instantiation for pm.h compliance 57 * This is done via auxio, but could be used as a fallback 58 * handler when auxio is not present-- unused for now... 59 */ 60 void (*pm_power_off)(void) = machine_power_off; 61 EXPORT_SYMBOL(pm_power_off); 62 63 /* 64 * sysctl - toggle power-off restriction for serial console 65 * systems in machine_power_off() 66 */ 67 int scons_pwroff = 1; 68 69 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); 70 71 struct task_struct *last_task_used_math = NULL; 72 struct thread_info *current_set[NR_CPUS]; 73 74 /* Idle loop support. */ 75 void arch_cpu_idle(void) 76 { 77 if (sparc_idle) 78 (*sparc_idle)(); 79 local_irq_enable(); 80 } 81 82 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 83 void machine_halt(void) 84 { 85 local_irq_enable(); 86 mdelay(8); 87 local_irq_disable(); 88 prom_halt(); 89 panic("Halt failed!"); 90 } 91 92 void machine_restart(char * cmd) 93 { 94 char *p; 95 96 local_irq_enable(); 97 mdelay(8); 98 local_irq_disable(); 99 100 p = strchr (reboot_command, '\n'); 101 if (p) *p = 0; 102 if (cmd) 103 prom_reboot(cmd); 104 if (*reboot_command) 105 prom_reboot(reboot_command); 106 prom_feval ("reset"); 107 panic("Reboot failed!"); 108 } 109 110 void machine_power_off(void) 111 { 112 if (auxio_power_register && 113 (!of_node_is_type(of_console_device, "serial") || scons_pwroff)) { 114 u8 power_register = sbus_readb(auxio_power_register); 115 power_register |= AUXIO_POWER_OFF; 116 sbus_writeb(power_register, auxio_power_register); 117 } 118 119 machine_halt(); 120 } 121 122 void show_regs(struct pt_regs *r) 123 { 124 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; 125 126 show_regs_print_info(KERN_DEFAULT); 127 128 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 129 r->psr, r->pc, r->npc, r->y, print_tainted()); 130 printk("PC: <%pS>\n", (void *) r->pc); 131 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 132 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 133 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 134 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 135 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 136 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 137 printk("RPC: <%pS>\n", (void *) r->u_regs[15]); 138 139 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 140 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 141 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 142 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 143 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 144 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 145 } 146 147 /* 148 * The show_stack is an external API which we do not use ourselves. 149 * The oops is printed in die_if_kernel. 150 */ 151 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 152 { 153 unsigned long pc, fp; 154 unsigned long task_base; 155 struct reg_window32 *rw; 156 int count = 0; 157 158 if (!tsk) 159 tsk = current; 160 161 if (tsk == current && !_ksp) 162 __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp)); 163 164 task_base = (unsigned long) task_stack_page(tsk); 165 fp = (unsigned long) _ksp; 166 do { 167 /* Bogus frame pointer? */ 168 if (fp < (task_base + sizeof(struct thread_info)) || 169 fp >= (task_base + (PAGE_SIZE << 1))) 170 break; 171 rw = (struct reg_window32 *) fp; 172 pc = rw->ins[7]; 173 printk("[%08lx : ", pc); 174 printk("%pS ] ", (void *) pc); 175 fp = rw->ins[6]; 176 } while (++count < 16); 177 printk("\n"); 178 } 179 180 /* 181 * Free current thread data structures etc.. 182 */ 183 void exit_thread(struct task_struct *tsk) 184 { 185 #ifndef CONFIG_SMP 186 if (last_task_used_math == tsk) { 187 #else 188 if (test_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU)) { 189 #endif 190 /* Keep process from leaving FPU in a bogon state. */ 191 put_psr(get_psr() | PSR_EF); 192 fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr, 193 &tsk->thread.fpqueue[0], &tsk->thread.fpqdepth); 194 #ifndef CONFIG_SMP 195 last_task_used_math = NULL; 196 #else 197 clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU); 198 #endif 199 } 200 } 201 202 void flush_thread(void) 203 { 204 current_thread_info()->w_saved = 0; 205 206 #ifndef CONFIG_SMP 207 if(last_task_used_math == current) { 208 #else 209 if (test_thread_flag(TIF_USEDFPU)) { 210 #endif 211 /* Clean the fpu. */ 212 put_psr(get_psr() | PSR_EF); 213 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 214 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 215 #ifndef CONFIG_SMP 216 last_task_used_math = NULL; 217 #else 218 clear_thread_flag(TIF_USEDFPU); 219 #endif 220 } 221 222 /* This task is no longer a kernel thread. */ 223 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 224 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 225 226 /* We must fixup kregs as well. */ 227 /* XXX This was not fixed for ti for a while, worked. Unused? */ 228 current->thread.kregs = (struct pt_regs *) 229 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 230 } 231 } 232 233 static inline struct sparc_stackf __user * 234 clone_stackframe(struct sparc_stackf __user *dst, 235 struct sparc_stackf __user *src) 236 { 237 unsigned long size, fp; 238 struct sparc_stackf *tmp; 239 struct sparc_stackf __user *sp; 240 241 if (get_user(tmp, &src->fp)) 242 return NULL; 243 244 fp = (unsigned long) tmp; 245 size = (fp - ((unsigned long) src)); 246 fp = (unsigned long) dst; 247 sp = (struct sparc_stackf __user *)(fp - size); 248 249 /* do_fork() grabs the parent semaphore, we must release it 250 * temporarily so we can build the child clone stack frame 251 * without deadlocking. 252 */ 253 if (__copy_user(sp, src, size)) 254 sp = NULL; 255 else if (put_user(fp, &sp->fp)) 256 sp = NULL; 257 258 return sp; 259 } 260 261 asmlinkage int sparc_do_fork(unsigned long clone_flags, 262 unsigned long stack_start, 263 struct pt_regs *regs, 264 unsigned long stack_size) 265 { 266 unsigned long parent_tid_ptr, child_tid_ptr; 267 unsigned long orig_i1 = regs->u_regs[UREG_I1]; 268 long ret; 269 270 parent_tid_ptr = regs->u_regs[UREG_I2]; 271 child_tid_ptr = regs->u_regs[UREG_I4]; 272 273 ret = do_fork(clone_flags, stack_start, stack_size, 274 (int __user *) parent_tid_ptr, 275 (int __user *) child_tid_ptr); 276 277 /* If we get an error and potentially restart the system 278 * call, we're screwed because copy_thread() clobbered 279 * the parent's %o1. So detect that case and restore it 280 * here. 281 */ 282 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) 283 regs->u_regs[UREG_I1] = orig_i1; 284 285 return ret; 286 } 287 288 /* Copy a Sparc thread. The fork() return value conventions 289 * under SunOS are nothing short of bletcherous: 290 * Parent --> %o0 == childs pid, %o1 == 0 291 * Child --> %o0 == parents pid, %o1 == 1 292 * 293 * NOTE: We have a separate fork kpsr/kwim because 294 * the parent could change these values between 295 * sys_fork invocation and when we reach here 296 * if the parent should sleep while trying to 297 * allocate the task_struct and kernel stack in 298 * do_fork(). 299 * XXX See comment above sys_vfork in sparc64. todo. 300 */ 301 extern void ret_from_fork(void); 302 extern void ret_from_kernel_thread(void); 303 304 int copy_thread(unsigned long clone_flags, unsigned long sp, 305 unsigned long arg, struct task_struct *p) 306 { 307 struct thread_info *ti = task_thread_info(p); 308 struct pt_regs *childregs, *regs = current_pt_regs(); 309 char *new_stack; 310 311 #ifndef CONFIG_SMP 312 if(last_task_used_math == current) { 313 #else 314 if (test_thread_flag(TIF_USEDFPU)) { 315 #endif 316 put_psr(get_psr() | PSR_EF); 317 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 318 &p->thread.fpqueue[0], &p->thread.fpqdepth); 319 } 320 321 /* 322 * p->thread_info new_stack childregs stack bottom 323 * ! ! ! ! 324 * V V (stk.fr.) V (pt_regs) V 325 * +----- - - - - - ------+===========+=============+ 326 */ 327 new_stack = task_stack_page(p) + THREAD_SIZE; 328 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 329 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 330 331 /* 332 * A new process must start with interrupts disabled, see schedule_tail() 333 * and finish_task_switch(). (If we do not do it and if a timer interrupt 334 * hits before we unlock and attempts to take the rq->lock, we deadlock.) 335 * 336 * Thus, kpsr |= PSR_PIL. 337 */ 338 ti->ksp = (unsigned long) new_stack; 339 p->thread.kregs = childregs; 340 341 if (unlikely(p->flags & PF_KTHREAD)) { 342 extern int nwindows; 343 unsigned long psr; 344 memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); 345 p->thread.flags |= SPARC_FLAG_KTHREAD; 346 p->thread.current_ds = KERNEL_DS; 347 ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); 348 childregs->u_regs[UREG_G1] = sp; /* function */ 349 childregs->u_regs[UREG_G2] = arg; 350 psr = childregs->psr = get_psr(); 351 ti->kpsr = psr | PSR_PIL; 352 ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows); 353 return 0; 354 } 355 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 356 childregs->u_regs[UREG_FP] = sp; 357 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 358 p->thread.current_ds = USER_DS; 359 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 360 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 361 ti->kwim = current->thread.fork_kwim; 362 363 if (sp != regs->u_regs[UREG_FP]) { 364 struct sparc_stackf __user *childstack; 365 struct sparc_stackf __user *parentstack; 366 367 /* 368 * This is a clone() call with supplied user stack. 369 * Set some valid stack frames to give to the child. 370 */ 371 childstack = (struct sparc_stackf __user *) 372 (sp & ~0xfUL); 373 parentstack = (struct sparc_stackf __user *) 374 regs->u_regs[UREG_FP]; 375 376 #if 0 377 printk("clone: parent stack:\n"); 378 show_stackframe(parentstack); 379 #endif 380 381 childstack = clone_stackframe(childstack, parentstack); 382 if (!childstack) 383 return -EFAULT; 384 385 #if 0 386 printk("clone: child stack:\n"); 387 show_stackframe(childstack); 388 #endif 389 390 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 391 } 392 393 #ifdef CONFIG_SMP 394 /* FPU must be disabled on SMP. */ 395 childregs->psr &= ~PSR_EF; 396 clear_tsk_thread_flag(p, TIF_USEDFPU); 397 #endif 398 399 /* Set the return value for the child. */ 400 childregs->u_regs[UREG_I0] = current->pid; 401 childregs->u_regs[UREG_I1] = 1; 402 403 /* Set the return value for the parent. */ 404 regs->u_regs[UREG_I1] = 0; 405 406 if (clone_flags & CLONE_SETTLS) 407 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 408 409 return 0; 410 } 411 412 /* 413 * fill in the fpu structure for a core dump. 414 */ 415 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 416 { 417 if (used_math()) { 418 memset(fpregs, 0, sizeof(*fpregs)); 419 fpregs->pr_q_entrysize = 8; 420 return 1; 421 } 422 #ifdef CONFIG_SMP 423 if (test_thread_flag(TIF_USEDFPU)) { 424 put_psr(get_psr() | PSR_EF); 425 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 426 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 427 if (regs != NULL) { 428 regs->psr &= ~(PSR_EF); 429 clear_thread_flag(TIF_USEDFPU); 430 } 431 } 432 #else 433 if (current == last_task_used_math) { 434 put_psr(get_psr() | PSR_EF); 435 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 436 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 437 if (regs != NULL) { 438 regs->psr &= ~(PSR_EF); 439 last_task_used_math = NULL; 440 } 441 } 442 #endif 443 memcpy(&fpregs->pr_fr.pr_regs[0], 444 ¤t->thread.float_regs[0], 445 (sizeof(unsigned long) * 32)); 446 fpregs->pr_fsr = current->thread.fsr; 447 fpregs->pr_qcnt = current->thread.fpqdepth; 448 fpregs->pr_q_entrysize = 8; 449 fpregs->pr_en = 1; 450 if(fpregs->pr_qcnt != 0) { 451 memcpy(&fpregs->pr_q[0], 452 ¤t->thread.fpqueue[0], 453 sizeof(struct fpq) * fpregs->pr_qcnt); 454 } 455 /* Zero out the rest. */ 456 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 457 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 458 return 1; 459 } 460 461 unsigned long get_wchan(struct task_struct *task) 462 { 463 unsigned long pc, fp, bias = 0; 464 unsigned long task_base = (unsigned long) task; 465 unsigned long ret = 0; 466 struct reg_window32 *rw; 467 int count = 0; 468 469 if (!task || task == current || 470 task->state == TASK_RUNNING) 471 goto out; 472 473 fp = task_thread_info(task)->ksp + bias; 474 do { 475 /* Bogus frame pointer? */ 476 if (fp < (task_base + sizeof(struct thread_info)) || 477 fp >= (task_base + (2 * PAGE_SIZE))) 478 break; 479 rw = (struct reg_window32 *) fp; 480 pc = rw->ins[7]; 481 if (!in_sched_functions(pc)) { 482 ret = pc; 483 goto out; 484 } 485 fp = rw->ins[6] + bias; 486 } while (++count < 16); 487 488 out: 489 return ret; 490 } 491 492