1 /* 2 * arch/sh/kernel/process.c 3 * 4 * This file handles the architecture-dependent parts of process handling.. 5 * 6 * Copyright (C) 1995 Linus Torvalds 7 * 8 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima 9 * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC 10 * Copyright (C) 2002 - 2008 Paul Mundt 11 * 12 * This file is subject to the terms and conditions of the GNU General Public 13 * License. See the file "COPYING" in the main directory of this archive 14 * for more details. 15 */ 16 #include <linux/module.h> 17 #include <linux/mm.h> 18 #include <linux/elfcore.h> 19 #include <linux/pm.h> 20 #include <linux/kallsyms.h> 21 #include <linux/kexec.h> 22 #include <linux/kdebug.h> 23 #include <linux/tick.h> 24 #include <linux/reboot.h> 25 #include <linux/fs.h> 26 #include <linux/ftrace.h> 27 #include <linux/preempt.h> 28 #include <asm/uaccess.h> 29 #include <asm/mmu_context.h> 30 #include <asm/pgalloc.h> 31 #include <asm/system.h> 32 #include <asm/ubc.h> 33 #include <asm/fpu.h> 34 #include <asm/syscalls.h> 35 #include <asm/watchdog.h> 36 37 int ubc_usercnt = 0; 38 39 #ifdef CONFIG_32BIT 40 static void watchdog_trigger_immediate(void) 41 { 42 sh_wdt_write_cnt(0xFF); 43 sh_wdt_write_csr(0xC2); 44 } 45 46 void machine_restart(char * __unused) 47 { 48 local_irq_disable(); 49 50 /* Use watchdog timer to trigger reset */ 51 watchdog_trigger_immediate(); 52 53 while (1) 54 cpu_sleep(); 55 } 56 #else 57 void machine_restart(char * __unused) 58 { 59 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */ 60 asm volatile("ldc %0, sr\n\t" 61 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001)); 62 } 63 #endif 64 65 void machine_halt(void) 66 { 67 local_irq_disable(); 68 69 while (1) 70 cpu_sleep(); 71 } 72 73 void machine_power_off(void) 74 { 75 if (pm_power_off) 76 pm_power_off(); 77 } 78 79 void show_regs(struct pt_regs * regs) 80 { 81 printk("\n"); 82 printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm); 83 printk("CPU : %d \t\t%s (%s %.*s)\n\n", 84 smp_processor_id(), print_tainted(), init_utsname()->release, 85 (int)strcspn(init_utsname()->version, " "), 86 init_utsname()->version); 87 88 print_symbol("PC is at %s\n", instruction_pointer(regs)); 89 print_symbol("PR is at %s\n", regs->pr); 90 91 printk("PC : %08lx SP : %08lx SR : %08lx ", 92 regs->pc, regs->regs[15], regs->sr); 93 #ifdef CONFIG_MMU 94 printk("TEA : %08x\n", ctrl_inl(MMU_TEA)); 95 #else 96 printk("\n"); 97 #endif 98 99 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n", 100 regs->regs[0],regs->regs[1], 101 regs->regs[2],regs->regs[3]); 102 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n", 103 regs->regs[4],regs->regs[5], 104 regs->regs[6],regs->regs[7]); 105 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n", 106 regs->regs[8],regs->regs[9], 107 regs->regs[10],regs->regs[11]); 108 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n", 109 regs->regs[12],regs->regs[13], 110 regs->regs[14]); 111 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", 112 regs->mach, regs->macl, regs->gbr, regs->pr); 113 114 show_trace(NULL, (unsigned long *)regs->regs[15], regs); 115 show_code(regs); 116 } 117 118 /* 119 * Create a kernel thread 120 */ 121 ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *)) 122 { 123 do_exit(fn(arg)); 124 } 125 126 /* Don't use this in BL=1(cli). Or else, CPU resets! */ 127 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 128 { 129 struct pt_regs regs; 130 int pid; 131 132 memset(®s, 0, sizeof(regs)); 133 regs.regs[4] = (unsigned long)arg; 134 regs.regs[5] = (unsigned long)fn; 135 136 regs.pc = (unsigned long)kernel_thread_helper; 137 regs.sr = (1 << 30); 138 139 /* Ok, create the new process.. */ 140 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, 141 ®s, 0, NULL, NULL); 142 143 return pid; 144 } 145 146 /* 147 * Free current thread data structures etc.. 148 */ 149 void exit_thread(void) 150 { 151 if (current->thread.ubc_pc) { 152 current->thread.ubc_pc = 0; 153 ubc_usercnt -= 1; 154 } 155 } 156 157 void flush_thread(void) 158 { 159 #if defined(CONFIG_SH_FPU) 160 struct task_struct *tsk = current; 161 /* Forget lazy FPU state */ 162 clear_fpu(tsk, task_pt_regs(tsk)); 163 clear_used_math(); 164 #endif 165 } 166 167 void release_thread(struct task_struct *dead_task) 168 { 169 /* do nothing */ 170 } 171 172 /* Fill in the fpu structure for a core dump.. */ 173 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) 174 { 175 int fpvalid = 0; 176 177 #if defined(CONFIG_SH_FPU) 178 struct task_struct *tsk = current; 179 180 fpvalid = !!tsk_used_math(tsk); 181 if (fpvalid) 182 fpvalid = !fpregs_get(tsk, NULL, 0, 183 sizeof(struct user_fpu_struct), 184 fpu, NULL); 185 #endif 186 187 return fpvalid; 188 } 189 190 asmlinkage void ret_from_fork(void); 191 192 int copy_thread(unsigned long clone_flags, unsigned long usp, 193 unsigned long unused, 194 struct task_struct *p, struct pt_regs *regs) 195 { 196 struct thread_info *ti = task_thread_info(p); 197 struct pt_regs *childregs; 198 #if defined(CONFIG_SH_FPU) || defined(CONFIG_SH_DSP) 199 struct task_struct *tsk = current; 200 #endif 201 202 #if defined(CONFIG_SH_FPU) 203 unlazy_fpu(tsk, regs); 204 p->thread.fpu = tsk->thread.fpu; 205 copy_to_stopped_child_used_math(p); 206 #endif 207 208 #if defined(CONFIG_SH_DSP) 209 if (is_dsp_enabled(tsk)) { 210 /* We can use the __save_dsp or just copy the struct: 211 * __save_dsp(p); 212 * p->thread.dsp_status.status |= SR_DSP 213 */ 214 p->thread.dsp_status = tsk->thread.dsp_status; 215 } 216 #endif 217 218 childregs = task_pt_regs(p); 219 *childregs = *regs; 220 221 if (user_mode(regs)) { 222 childregs->regs[15] = usp; 223 ti->addr_limit = USER_DS; 224 } else { 225 childregs->regs[15] = (unsigned long)childregs; 226 ti->addr_limit = KERNEL_DS; 227 } 228 229 if (clone_flags & CLONE_SETTLS) 230 childregs->gbr = childregs->regs[0]; 231 232 childregs->regs[0] = 0; /* Set return value for child */ 233 234 p->thread.sp = (unsigned long) childregs; 235 p->thread.pc = (unsigned long) ret_from_fork; 236 237 p->thread.ubc_pc = 0; 238 239 return 0; 240 } 241 242 /* Tracing by user break controller. */ 243 static void ubc_set_tracing(int asid, unsigned long pc) 244 { 245 #if defined(CONFIG_CPU_SH4A) 246 unsigned long val; 247 248 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE); 249 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid)); 250 251 ctrl_outl(val, UBC_CBR0); 252 ctrl_outl(pc, UBC_CAR0); 253 ctrl_outl(0x0, UBC_CAMR0); 254 ctrl_outl(0x0, UBC_CBCR); 255 256 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE); 257 ctrl_outl(val, UBC_CRR0); 258 259 /* Read UBC register that we wrote last, for checking update */ 260 val = ctrl_inl(UBC_CRR0); 261 262 #else /* CONFIG_CPU_SH4A */ 263 ctrl_outl(pc, UBC_BARA); 264 265 #ifdef CONFIG_MMU 266 ctrl_outb(asid, UBC_BASRA); 267 #endif 268 269 ctrl_outl(0, UBC_BAMRA); 270 271 if (current_cpu_data.type == CPU_SH7729 || 272 current_cpu_data.type == CPU_SH7710 || 273 current_cpu_data.type == CPU_SH7712 || 274 current_cpu_data.type == CPU_SH7203){ 275 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA); 276 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR); 277 } else { 278 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA); 279 ctrl_outw(BRCR_PCBA, UBC_BRCR); 280 } 281 #endif /* CONFIG_CPU_SH4A */ 282 } 283 284 /* 285 * switch_to(x,y) should switch tasks from x to y. 286 * 287 */ 288 __notrace_funcgraph struct task_struct * 289 __switch_to(struct task_struct *prev, struct task_struct *next) 290 { 291 struct thread_struct *next_t = &next->thread; 292 293 #if defined(CONFIG_SH_FPU) 294 unlazy_fpu(prev, task_pt_regs(prev)); 295 296 /* we're going to use this soon, after a few expensive things */ 297 if (next->fpu_counter > 5) 298 prefetch(&next_t->fpu.hard); 299 #endif 300 301 #ifdef CONFIG_MMU 302 /* 303 * Restore the kernel mode register 304 * k7 (r7_bank1) 305 */ 306 asm volatile("ldc %0, r7_bank" 307 : /* no output */ 308 : "r" (task_thread_info(next))); 309 #endif 310 311 /* If no tasks are using the UBC, we're done */ 312 if (ubc_usercnt == 0) 313 /* If no tasks are using the UBC, we're done */; 314 else if (next->thread.ubc_pc && next->mm) { 315 int asid = 0; 316 #ifdef CONFIG_MMU 317 asid |= cpu_asid(smp_processor_id(), next->mm); 318 #endif 319 ubc_set_tracing(asid, next->thread.ubc_pc); 320 } else { 321 #if defined(CONFIG_CPU_SH4A) 322 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 323 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 324 #else 325 ctrl_outw(0, UBC_BBRA); 326 ctrl_outw(0, UBC_BBRB); 327 #endif 328 } 329 330 #if defined(CONFIG_SH_FPU) 331 /* If the task has used fpu the last 5 timeslices, just do a full 332 * restore of the math state immediately to avoid the trap; the 333 * chances of needing FPU soon are obviously high now 334 */ 335 if (next->fpu_counter > 5) { 336 fpu_state_restore(task_pt_regs(next)); 337 } 338 #endif 339 340 return prev; 341 } 342 343 asmlinkage int sys_fork(unsigned long r4, unsigned long r5, 344 unsigned long r6, unsigned long r7, 345 struct pt_regs __regs) 346 { 347 #ifdef CONFIG_MMU 348 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 349 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); 350 #else 351 /* fork almost works, enough to trick you into looking elsewhere :-( */ 352 return -EINVAL; 353 #endif 354 } 355 356 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, 357 unsigned long parent_tidptr, 358 unsigned long child_tidptr, 359 struct pt_regs __regs) 360 { 361 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 362 if (!newsp) 363 newsp = regs->regs[15]; 364 return do_fork(clone_flags, newsp, regs, 0, 365 (int __user *)parent_tidptr, 366 (int __user *)child_tidptr); 367 } 368 369 /* 370 * This is trivial, and on the face of it looks like it 371 * could equally well be done in user mode. 372 * 373 * Not so, for quite unobvious reasons - register pressure. 374 * In user mode vfork() cannot have a stack frame, and if 375 * done by calling the "clone()" system call directly, you 376 * do not have enough call-clobbered registers to hold all 377 * the information you need. 378 */ 379 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, 380 unsigned long r6, unsigned long r7, 381 struct pt_regs __regs) 382 { 383 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 384 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, 385 0, NULL, NULL); 386 } 387 388 /* 389 * sys_execve() executes a new program. 390 */ 391 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv, 392 char __user * __user *uenvp, unsigned long r7, 393 struct pt_regs __regs) 394 { 395 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 396 int error; 397 char *filename; 398 399 filename = getname(ufilename); 400 error = PTR_ERR(filename); 401 if (IS_ERR(filename)) 402 goto out; 403 404 error = do_execve(filename, uargv, uenvp, regs); 405 putname(filename); 406 out: 407 return error; 408 } 409 410 unsigned long get_wchan(struct task_struct *p) 411 { 412 unsigned long pc; 413 414 if (!p || p == current || p->state == TASK_RUNNING) 415 return 0; 416 417 /* 418 * The same comment as on the Alpha applies here, too ... 419 */ 420 pc = thread_saved_pc(p); 421 422 #ifdef CONFIG_FRAME_POINTER 423 if (in_sched_functions(pc)) { 424 unsigned long schedule_frame = (unsigned long)p->thread.sp; 425 return ((unsigned long *)schedule_frame)[21]; 426 } 427 #endif 428 429 return pc; 430 } 431 432 asmlinkage void break_point_trap(void) 433 { 434 /* Clear tracing. */ 435 #if defined(CONFIG_CPU_SH4A) 436 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 437 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 438 #else 439 ctrl_outw(0, UBC_BBRA); 440 ctrl_outw(0, UBC_BBRB); 441 ctrl_outl(0, UBC_BRCR); 442 #endif 443 current->thread.ubc_pc = 0; 444 ubc_usercnt -= 1; 445 446 force_sig(SIGTRAP, current); 447 } 448