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/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 (!of_node_is_type(of_console_device, "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 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, const char *loglvl) 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("%s[%08lx : ", loglvl, pc); 173 printk("%s%pS ] ", loglvl, (void *) pc); 174 fp = rw->ins[6]; 175 } while (++count < 16); 176 printk("%s\n", loglvl); 177 } 178 179 /* 180 * Free current thread data structures etc.. 181 */ 182 void exit_thread(struct task_struct *tsk) 183 { 184 #ifndef CONFIG_SMP 185 if (last_task_used_math == tsk) { 186 #else 187 if (test_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU)) { 188 #endif 189 /* Keep process from leaving FPU in a bogon state. */ 190 put_psr(get_psr() | PSR_EF); 191 fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr, 192 &tsk->thread.fpqueue[0], &tsk->thread.fpqdepth); 193 #ifndef CONFIG_SMP 194 last_task_used_math = NULL; 195 #else 196 clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU); 197 #endif 198 } 199 } 200 201 void flush_thread(void) 202 { 203 current_thread_info()->w_saved = 0; 204 205 #ifndef CONFIG_SMP 206 if(last_task_used_math == current) { 207 #else 208 if (test_thread_flag(TIF_USEDFPU)) { 209 #endif 210 /* Clean the fpu. */ 211 put_psr(get_psr() | PSR_EF); 212 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 213 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 214 #ifndef CONFIG_SMP 215 last_task_used_math = NULL; 216 #else 217 clear_thread_flag(TIF_USEDFPU); 218 #endif 219 } 220 221 /* This task is no longer a kernel thread. */ 222 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 223 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 224 225 /* We must fixup kregs as well. */ 226 /* XXX This was not fixed for ti for a while, worked. Unused? */ 227 current->thread.kregs = (struct pt_regs *) 228 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 229 } 230 } 231 232 static inline struct sparc_stackf __user * 233 clone_stackframe(struct sparc_stackf __user *dst, 234 struct sparc_stackf __user *src) 235 { 236 unsigned long size, fp; 237 struct sparc_stackf *tmp; 238 struct sparc_stackf __user *sp; 239 240 if (get_user(tmp, &src->fp)) 241 return NULL; 242 243 fp = (unsigned long) tmp; 244 size = (fp - ((unsigned long) src)); 245 fp = (unsigned long) dst; 246 sp = (struct sparc_stackf __user *)(fp - size); 247 248 /* do_fork() grabs the parent semaphore, we must release it 249 * temporarily so we can build the child clone stack frame 250 * without deadlocking. 251 */ 252 if (__copy_user(sp, src, size)) 253 sp = NULL; 254 else if (put_user(fp, &sp->fp)) 255 sp = NULL; 256 257 return sp; 258 } 259 260 /* Copy a Sparc thread. The fork() return value conventions 261 * under SunOS are nothing short of bletcherous: 262 * Parent --> %o0 == childs pid, %o1 == 0 263 * Child --> %o0 == parents pid, %o1 == 1 264 * 265 * NOTE: We have a separate fork kpsr/kwim because 266 * the parent could change these values between 267 * sys_fork invocation and when we reach here 268 * if the parent should sleep while trying to 269 * allocate the task_struct and kernel stack in 270 * do_fork(). 271 * XXX See comment above sys_vfork in sparc64. todo. 272 */ 273 extern void ret_from_fork(void); 274 extern void ret_from_kernel_thread(void); 275 276 int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, 277 struct task_struct *p, unsigned long tls) 278 { 279 struct thread_info *ti = task_thread_info(p); 280 struct pt_regs *childregs, *regs = current_pt_regs(); 281 char *new_stack; 282 283 #ifndef CONFIG_SMP 284 if(last_task_used_math == current) { 285 #else 286 if (test_thread_flag(TIF_USEDFPU)) { 287 #endif 288 put_psr(get_psr() | PSR_EF); 289 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 290 &p->thread.fpqueue[0], &p->thread.fpqdepth); 291 } 292 293 /* 294 * p->thread_info new_stack childregs stack bottom 295 * ! ! ! ! 296 * V V (stk.fr.) V (pt_regs) V 297 * +----- - - - - - ------+===========+=============+ 298 */ 299 new_stack = task_stack_page(p) + THREAD_SIZE; 300 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 301 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 302 303 /* 304 * A new process must start with interrupts disabled, see schedule_tail() 305 * and finish_task_switch(). (If we do not do it and if a timer interrupt 306 * hits before we unlock and attempts to take the rq->lock, we deadlock.) 307 * 308 * Thus, kpsr |= PSR_PIL. 309 */ 310 ti->ksp = (unsigned long) new_stack; 311 p->thread.kregs = childregs; 312 313 if (unlikely(p->flags & PF_KTHREAD)) { 314 extern int nwindows; 315 unsigned long psr; 316 memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); 317 p->thread.flags |= SPARC_FLAG_KTHREAD; 318 p->thread.current_ds = KERNEL_DS; 319 ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); 320 childregs->u_regs[UREG_G1] = sp; /* function */ 321 childregs->u_regs[UREG_G2] = arg; 322 psr = childregs->psr = get_psr(); 323 ti->kpsr = psr | PSR_PIL; 324 ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows); 325 return 0; 326 } 327 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 328 childregs->u_regs[UREG_FP] = sp; 329 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 330 p->thread.current_ds = USER_DS; 331 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 332 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 333 ti->kwim = current->thread.fork_kwim; 334 335 if (sp != regs->u_regs[UREG_FP]) { 336 struct sparc_stackf __user *childstack; 337 struct sparc_stackf __user *parentstack; 338 339 /* 340 * This is a clone() call with supplied user stack. 341 * Set some valid stack frames to give to the child. 342 */ 343 childstack = (struct sparc_stackf __user *) 344 (sp & ~0xfUL); 345 parentstack = (struct sparc_stackf __user *) 346 regs->u_regs[UREG_FP]; 347 348 #if 0 349 printk("clone: parent stack:\n"); 350 show_stackframe(parentstack); 351 #endif 352 353 childstack = clone_stackframe(childstack, parentstack); 354 if (!childstack) 355 return -EFAULT; 356 357 #if 0 358 printk("clone: child stack:\n"); 359 show_stackframe(childstack); 360 #endif 361 362 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 363 } 364 365 #ifdef CONFIG_SMP 366 /* FPU must be disabled on SMP. */ 367 childregs->psr &= ~PSR_EF; 368 clear_tsk_thread_flag(p, TIF_USEDFPU); 369 #endif 370 371 /* Set the return value for the child. */ 372 childregs->u_regs[UREG_I0] = current->pid; 373 childregs->u_regs[UREG_I1] = 1; 374 375 /* Set the return value for the parent. */ 376 regs->u_regs[UREG_I1] = 0; 377 378 if (clone_flags & CLONE_SETTLS) 379 childregs->u_regs[UREG_G7] = tls; 380 381 return 0; 382 } 383 384 /* 385 * fill in the fpu structure for a core dump. 386 */ 387 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 388 { 389 if (used_math()) { 390 memset(fpregs, 0, sizeof(*fpregs)); 391 fpregs->pr_q_entrysize = 8; 392 return 1; 393 } 394 #ifdef CONFIG_SMP 395 if (test_thread_flag(TIF_USEDFPU)) { 396 put_psr(get_psr() | PSR_EF); 397 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 398 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 399 if (regs != NULL) { 400 regs->psr &= ~(PSR_EF); 401 clear_thread_flag(TIF_USEDFPU); 402 } 403 } 404 #else 405 if (current == last_task_used_math) { 406 put_psr(get_psr() | PSR_EF); 407 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 408 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 409 if (regs != NULL) { 410 regs->psr &= ~(PSR_EF); 411 last_task_used_math = NULL; 412 } 413 } 414 #endif 415 memcpy(&fpregs->pr_fr.pr_regs[0], 416 ¤t->thread.float_regs[0], 417 (sizeof(unsigned long) * 32)); 418 fpregs->pr_fsr = current->thread.fsr; 419 fpregs->pr_qcnt = current->thread.fpqdepth; 420 fpregs->pr_q_entrysize = 8; 421 fpregs->pr_en = 1; 422 if(fpregs->pr_qcnt != 0) { 423 memcpy(&fpregs->pr_q[0], 424 ¤t->thread.fpqueue[0], 425 sizeof(struct fpq) * fpregs->pr_qcnt); 426 } 427 /* Zero out the rest. */ 428 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 429 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 430 return 1; 431 } 432 433 unsigned long get_wchan(struct task_struct *task) 434 { 435 unsigned long pc, fp, bias = 0; 436 unsigned long task_base = (unsigned long) task; 437 unsigned long ret = 0; 438 struct reg_window32 *rw; 439 int count = 0; 440 441 if (!task || task == current || 442 task->state == TASK_RUNNING) 443 goto out; 444 445 fp = task_thread_info(task)->ksp + bias; 446 do { 447 /* Bogus frame pointer? */ 448 if (fp < (task_base + sizeof(struct thread_info)) || 449 fp >= (task_base + (2 * PAGE_SIZE))) 450 break; 451 rw = (struct reg_window32 *) fp; 452 pc = rw->ins[7]; 453 if (!in_sched_functions(pc)) { 454 ret = pc; 455 goto out; 456 } 457 fp = rw->ins[6] + bias; 458 } while (++count < 16); 459 460 out: 461 return ret; 462 } 463 464