1 /* $Id: process.c,v 1.28 2004/05/05 16:54:23 lethal Exp $ 2 * 3 * linux/arch/sh/kernel/process.c 4 * 5 * Copyright (C) 1995 Linus Torvalds 6 * 7 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima 8 * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC 9 */ 10 11 /* 12 * This file handles the architecture-dependent parts of process handling.. 13 */ 14 15 #include <linux/module.h> 16 #include <linux/unistd.h> 17 #include <linux/mm.h> 18 #include <linux/elfcore.h> 19 #include <linux/a.out.h> 20 #include <linux/slab.h> 21 #include <linux/pm.h> 22 #include <linux/ptrace.h> 23 #include <linux/kallsyms.h> 24 #include <linux/kexec.h> 25 26 #include <asm/io.h> 27 #include <asm/uaccess.h> 28 #include <asm/mmu_context.h> 29 #include <asm/elf.h> 30 #include <asm/ubc.h> 31 32 static int hlt_counter=0; 33 34 int ubc_usercnt = 0; 35 36 #define HARD_IDLE_TIMEOUT (HZ / 3) 37 38 void (*pm_idle)(void); 39 40 void (*pm_power_off)(void); 41 EXPORT_SYMBOL(pm_power_off); 42 43 void disable_hlt(void) 44 { 45 hlt_counter++; 46 } 47 48 EXPORT_SYMBOL(disable_hlt); 49 50 void enable_hlt(void) 51 { 52 hlt_counter--; 53 } 54 55 EXPORT_SYMBOL(enable_hlt); 56 57 void default_idle(void) 58 { 59 if (!hlt_counter) 60 cpu_sleep(); 61 else 62 cpu_relax(); 63 } 64 65 void cpu_idle(void) 66 { 67 /* endless idle loop with no priority at all */ 68 while (1) { 69 void (*idle)(void) = pm_idle; 70 71 if (!idle) 72 idle = default_idle; 73 74 while (!need_resched()) 75 idle(); 76 77 preempt_enable_no_resched(); 78 schedule(); 79 preempt_disable(); 80 } 81 } 82 83 void machine_restart(char * __unused) 84 { 85 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */ 86 asm volatile("ldc %0, sr\n\t" 87 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001)); 88 } 89 90 void machine_halt(void) 91 { 92 local_irq_disable(); 93 94 while (1) 95 cpu_sleep(); 96 } 97 98 void machine_power_off(void) 99 { 100 if (pm_power_off) 101 pm_power_off(); 102 } 103 104 void show_regs(struct pt_regs * regs) 105 { 106 printk("\n"); 107 printk("Pid : %d, Comm: %20s\n", current->pid, current->comm); 108 print_symbol("PC is at %s\n", instruction_pointer(regs)); 109 printk("PC : %08lx SP : %08lx SR : %08lx ", 110 regs->pc, regs->regs[15], regs->sr); 111 #ifdef CONFIG_MMU 112 printk("TEA : %08x ", ctrl_inl(MMU_TEA)); 113 #else 114 printk(" "); 115 #endif 116 printk("%s\n", print_tainted()); 117 118 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n", 119 regs->regs[0],regs->regs[1], 120 regs->regs[2],regs->regs[3]); 121 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n", 122 regs->regs[4],regs->regs[5], 123 regs->regs[6],regs->regs[7]); 124 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n", 125 regs->regs[8],regs->regs[9], 126 regs->regs[10],regs->regs[11]); 127 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n", 128 regs->regs[12],regs->regs[13], 129 regs->regs[14]); 130 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", 131 regs->mach, regs->macl, regs->gbr, regs->pr); 132 133 show_trace(NULL, (unsigned long *)regs->regs[15], regs); 134 } 135 136 /* 137 * Create a kernel thread 138 */ 139 140 /* 141 * This is the mechanism for creating a new kernel thread. 142 * 143 */ 144 extern void kernel_thread_helper(void); 145 __asm__(".align 5\n" 146 "kernel_thread_helper:\n\t" 147 "jsr @r5\n\t" 148 " nop\n\t" 149 "mov.l 1f, r1\n\t" 150 "jsr @r1\n\t" 151 " mov r0, r4\n\t" 152 ".align 2\n\t" 153 "1:.long do_exit"); 154 155 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 156 { /* Don't use this in BL=1(cli). Or else, CPU resets! */ 157 struct pt_regs regs; 158 159 memset(®s, 0, sizeof(regs)); 160 regs.regs[4] = (unsigned long) arg; 161 regs.regs[5] = (unsigned long) fn; 162 163 regs.pc = (unsigned long) kernel_thread_helper; 164 regs.sr = (1 << 30); 165 166 /* Ok, create the new process.. */ 167 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 168 } 169 170 /* 171 * Free current thread data structures etc.. 172 */ 173 void exit_thread(void) 174 { 175 if (current->thread.ubc_pc) { 176 current->thread.ubc_pc = 0; 177 ubc_usercnt -= 1; 178 } 179 } 180 181 void flush_thread(void) 182 { 183 #if defined(CONFIG_SH_FPU) 184 struct task_struct *tsk = current; 185 /* Forget lazy FPU state */ 186 clear_fpu(tsk, task_pt_regs(tsk)); 187 clear_used_math(); 188 #endif 189 } 190 191 void release_thread(struct task_struct *dead_task) 192 { 193 /* do nothing */ 194 } 195 196 /* Fill in the fpu structure for a core dump.. */ 197 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) 198 { 199 int fpvalid = 0; 200 201 #if defined(CONFIG_SH_FPU) 202 struct task_struct *tsk = current; 203 204 fpvalid = !!tsk_used_math(tsk); 205 if (fpvalid) { 206 unlazy_fpu(tsk, regs); 207 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu)); 208 } 209 #endif 210 211 return fpvalid; 212 } 213 214 /* 215 * Capture the user space registers if the task is not running (in user space) 216 */ 217 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) 218 { 219 struct pt_regs ptregs; 220 221 ptregs = *task_pt_regs(tsk); 222 elf_core_copy_regs(regs, &ptregs); 223 224 return 1; 225 } 226 227 int 228 dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *fpu) 229 { 230 int fpvalid = 0; 231 232 #if defined(CONFIG_SH_FPU) 233 fpvalid = !!tsk_used_math(tsk); 234 if (fpvalid) { 235 unlazy_fpu(tsk, task_pt_regs(tsk)); 236 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu)); 237 } 238 #endif 239 240 return fpvalid; 241 } 242 243 asmlinkage void ret_from_fork(void); 244 245 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 246 unsigned long unused, 247 struct task_struct *p, struct pt_regs *regs) 248 { 249 struct thread_info *ti = task_thread_info(p); 250 struct pt_regs *childregs; 251 #if defined(CONFIG_SH_FPU) 252 struct task_struct *tsk = current; 253 254 unlazy_fpu(tsk, regs); 255 p->thread.fpu = tsk->thread.fpu; 256 copy_to_stopped_child_used_math(p); 257 #endif 258 259 childregs = task_pt_regs(p); 260 *childregs = *regs; 261 262 if (user_mode(regs)) { 263 childregs->regs[15] = usp; 264 ti->addr_limit = USER_DS; 265 } else { 266 childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE; 267 ti->addr_limit = KERNEL_DS; 268 } 269 if (clone_flags & CLONE_SETTLS) { 270 childregs->gbr = childregs->regs[0]; 271 } 272 childregs->regs[0] = 0; /* Set return value for child */ 273 274 p->thread.sp = (unsigned long) childregs; 275 p->thread.pc = (unsigned long) ret_from_fork; 276 277 p->thread.ubc_pc = 0; 278 279 return 0; 280 } 281 282 /* Tracing by user break controller. */ 283 static void 284 ubc_set_tracing(int asid, unsigned long pc) 285 { 286 #if defined(CONFIG_CPU_SH4A) 287 unsigned long val; 288 289 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE); 290 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid)); 291 292 ctrl_outl(val, UBC_CBR0); 293 ctrl_outl(pc, UBC_CAR0); 294 ctrl_outl(0x0, UBC_CAMR0); 295 ctrl_outl(0x0, UBC_CBCR); 296 297 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE); 298 ctrl_outl(val, UBC_CRR0); 299 300 /* Read UBC register that we writed last. For chekking UBC Register changed */ 301 val = ctrl_inl(UBC_CRR0); 302 303 #else /* CONFIG_CPU_SH4A */ 304 ctrl_outl(pc, UBC_BARA); 305 306 #ifdef CONFIG_MMU 307 /* We don't have any ASID settings for the SH-2! */ 308 if (cpu_data->type != CPU_SH7604) 309 ctrl_outb(asid, UBC_BASRA); 310 #endif 311 312 ctrl_outl(0, UBC_BAMRA); 313 314 if (cpu_data->type == CPU_SH7729 || cpu_data->type == CPU_SH7710) { 315 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA); 316 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR); 317 } else { 318 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA); 319 ctrl_outw(BRCR_PCBA, UBC_BRCR); 320 } 321 #endif /* CONFIG_CPU_SH4A */ 322 } 323 324 /* 325 * switch_to(x,y) should switch tasks from x to y. 326 * 327 */ 328 struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next) 329 { 330 #if defined(CONFIG_SH_FPU) 331 unlazy_fpu(prev, task_pt_regs(prev)); 332 #endif 333 334 #ifdef CONFIG_PREEMPT 335 { 336 unsigned long flags; 337 struct pt_regs *regs; 338 339 local_irq_save(flags); 340 regs = task_pt_regs(prev); 341 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) { 342 int offset = (int)regs->regs[15]; 343 344 /* Reset stack pointer: clear critical region mark */ 345 regs->regs[15] = regs->regs[1]; 346 if (regs->pc < regs->regs[0]) 347 /* Go to rewind point */ 348 regs->pc = regs->regs[0] + offset; 349 } 350 local_irq_restore(flags); 351 } 352 #endif 353 354 #ifdef CONFIG_MMU 355 /* 356 * Restore the kernel mode register 357 * k7 (r7_bank1) 358 */ 359 asm volatile("ldc %0, r7_bank" 360 : /* no output */ 361 : "r" (task_thread_info(next))); 362 #endif 363 364 /* If no tasks are using the UBC, we're done */ 365 if (ubc_usercnt == 0) 366 /* If no tasks are using the UBC, we're done */; 367 else if (next->thread.ubc_pc && next->mm) { 368 int asid = 0; 369 #ifdef CONFIG_MMU 370 asid |= next->mm->context.id & MMU_CONTEXT_ASID_MASK; 371 #endif 372 ubc_set_tracing(asid, next->thread.ubc_pc); 373 } else { 374 #if defined(CONFIG_CPU_SH4A) 375 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 376 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 377 #else 378 ctrl_outw(0, UBC_BBRA); 379 ctrl_outw(0, UBC_BBRB); 380 #endif 381 } 382 383 return prev; 384 } 385 386 asmlinkage int sys_fork(unsigned long r4, unsigned long r5, 387 unsigned long r6, unsigned long r7, 388 struct pt_regs __regs) 389 { 390 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 391 #ifdef CONFIG_MMU 392 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); 393 #else 394 /* fork almost works, enough to trick you into looking elsewhere :-( */ 395 return -EINVAL; 396 #endif 397 } 398 399 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, 400 unsigned long parent_tidptr, 401 unsigned long child_tidptr, 402 struct pt_regs __regs) 403 { 404 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 405 if (!newsp) 406 newsp = regs->regs[15]; 407 return do_fork(clone_flags, newsp, regs, 0, 408 (int __user *)parent_tidptr, (int __user *)child_tidptr); 409 } 410 411 /* 412 * This is trivial, and on the face of it looks like it 413 * could equally well be done in user mode. 414 * 415 * Not so, for quite unobvious reasons - register pressure. 416 * In user mode vfork() cannot have a stack frame, and if 417 * done by calling the "clone()" system call directly, you 418 * do not have enough call-clobbered registers to hold all 419 * the information you need. 420 */ 421 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, 422 unsigned long r6, unsigned long r7, 423 struct pt_regs __regs) 424 { 425 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 426 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, 427 0, NULL, NULL); 428 } 429 430 /* 431 * sys_execve() executes a new program. 432 */ 433 asmlinkage int sys_execve(char *ufilename, char **uargv, 434 char **uenvp, unsigned long r7, 435 struct pt_regs __regs) 436 { 437 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 438 int error; 439 char *filename; 440 441 filename = getname((char __user *)ufilename); 442 error = PTR_ERR(filename); 443 if (IS_ERR(filename)) 444 goto out; 445 446 error = do_execve(filename, 447 (char __user * __user *)uargv, 448 (char __user * __user *)uenvp, 449 regs); 450 if (error == 0) { 451 task_lock(current); 452 current->ptrace &= ~PT_DTRACE; 453 task_unlock(current); 454 } 455 putname(filename); 456 out: 457 return error; 458 } 459 460 unsigned long get_wchan(struct task_struct *p) 461 { 462 unsigned long schedule_frame; 463 unsigned long pc; 464 465 if (!p || p == current || p->state == TASK_RUNNING) 466 return 0; 467 468 /* 469 * The same comment as on the Alpha applies here, too ... 470 */ 471 pc = thread_saved_pc(p); 472 if (in_sched_functions(pc)) { 473 schedule_frame = (unsigned long)p->thread.sp; 474 return ((unsigned long *)schedule_frame)[21]; 475 } 476 477 return pc; 478 } 479 480 asmlinkage void break_point_trap(void) 481 { 482 /* Clear tracing. */ 483 #if defined(CONFIG_CPU_SH4A) 484 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 485 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 486 #else 487 ctrl_outw(0, UBC_BBRA); 488 ctrl_outw(0, UBC_BBRB); 489 #endif 490 current->thread.ubc_pc = 0; 491 ubc_usercnt -= 1; 492 493 force_sig(SIGTRAP, current); 494 } 495 496 asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5, 497 unsigned long r6, unsigned long r7, 498 struct pt_regs __regs) 499 { 500 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 501 502 /* Rewind */ 503 regs->pc -= 2; 504 505 #ifdef CONFIG_BUG 506 if (__kernel_text_address(instruction_pointer(regs))) { 507 u16 insn = *(u16 *)instruction_pointer(regs); 508 if (insn == TRAPA_BUG_OPCODE) 509 handle_BUG(regs); 510 } 511 #endif 512 513 force_sig(SIGTRAP, current); 514 } 515