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 = SR_MD; 138 #if defined(CONFIG_SH_FPU) 139 regs.sr |= SR_FD; 140 #endif 141 142 /* Ok, create the new process.. */ 143 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, 144 ®s, 0, NULL, NULL); 145 146 return pid; 147 } 148 EXPORT_SYMBOL(kernel_thread); 149 150 /* 151 * Free current thread data structures etc.. 152 */ 153 void exit_thread(void) 154 { 155 if (current->thread.ubc_pc) { 156 current->thread.ubc_pc = 0; 157 ubc_usercnt -= 1; 158 } 159 } 160 161 void flush_thread(void) 162 { 163 #if defined(CONFIG_SH_FPU) 164 struct task_struct *tsk = current; 165 /* Forget lazy FPU state */ 166 clear_fpu(tsk, task_pt_regs(tsk)); 167 clear_used_math(); 168 #endif 169 } 170 171 void release_thread(struct task_struct *dead_task) 172 { 173 /* do nothing */ 174 } 175 176 /* Fill in the fpu structure for a core dump.. */ 177 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) 178 { 179 int fpvalid = 0; 180 181 #if defined(CONFIG_SH_FPU) 182 struct task_struct *tsk = current; 183 184 fpvalid = !!tsk_used_math(tsk); 185 if (fpvalid) 186 fpvalid = !fpregs_get(tsk, NULL, 0, 187 sizeof(struct user_fpu_struct), 188 fpu, NULL); 189 #endif 190 191 return fpvalid; 192 } 193 EXPORT_SYMBOL(dump_fpu); 194 195 /* 196 * This gets called before we allocate a new thread and copy 197 * the current task into it. 198 */ 199 void prepare_to_copy(struct task_struct *tsk) 200 { 201 unlazy_fpu(tsk, task_pt_regs(tsk)); 202 } 203 204 asmlinkage void ret_from_fork(void); 205 206 int copy_thread(unsigned long clone_flags, unsigned long usp, 207 unsigned long unused, 208 struct task_struct *p, struct pt_regs *regs) 209 { 210 struct thread_info *ti = task_thread_info(p); 211 struct pt_regs *childregs; 212 #if defined(CONFIG_SH_DSP) 213 struct task_struct *tsk = current; 214 #endif 215 216 #if defined(CONFIG_SH_DSP) 217 if (is_dsp_enabled(tsk)) { 218 /* We can use the __save_dsp or just copy the struct: 219 * __save_dsp(p); 220 * p->thread.dsp_status.status |= SR_DSP 221 */ 222 p->thread.dsp_status = tsk->thread.dsp_status; 223 } 224 #endif 225 226 childregs = task_pt_regs(p); 227 *childregs = *regs; 228 229 if (user_mode(regs)) { 230 childregs->regs[15] = usp; 231 ti->addr_limit = USER_DS; 232 } else { 233 childregs->regs[15] = (unsigned long)childregs; 234 ti->addr_limit = KERNEL_DS; 235 ti->status &= ~TS_USEDFPU; 236 p->fpu_counter = 0; 237 } 238 239 if (clone_flags & CLONE_SETTLS) 240 childregs->gbr = childregs->regs[0]; 241 242 childregs->regs[0] = 0; /* Set return value for child */ 243 244 p->thread.sp = (unsigned long) childregs; 245 p->thread.pc = (unsigned long) ret_from_fork; 246 247 p->thread.ubc_pc = 0; 248 249 return 0; 250 } 251 252 /* Tracing by user break controller. */ 253 static void ubc_set_tracing(int asid, unsigned long pc) 254 { 255 #if defined(CONFIG_CPU_SH4A) 256 unsigned long val; 257 258 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE); 259 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid)); 260 261 ctrl_outl(val, UBC_CBR0); 262 ctrl_outl(pc, UBC_CAR0); 263 ctrl_outl(0x0, UBC_CAMR0); 264 ctrl_outl(0x0, UBC_CBCR); 265 266 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE); 267 ctrl_outl(val, UBC_CRR0); 268 269 /* Read UBC register that we wrote last, for checking update */ 270 val = ctrl_inl(UBC_CRR0); 271 272 #else /* CONFIG_CPU_SH4A */ 273 ctrl_outl(pc, UBC_BARA); 274 275 #ifdef CONFIG_MMU 276 ctrl_outb(asid, UBC_BASRA); 277 #endif 278 279 ctrl_outl(0, UBC_BAMRA); 280 281 if (current_cpu_data.type == CPU_SH7729 || 282 current_cpu_data.type == CPU_SH7710 || 283 current_cpu_data.type == CPU_SH7712 || 284 current_cpu_data.type == CPU_SH7203){ 285 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA); 286 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR); 287 } else { 288 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA); 289 ctrl_outw(BRCR_PCBA, UBC_BRCR); 290 } 291 #endif /* CONFIG_CPU_SH4A */ 292 } 293 294 /* 295 * switch_to(x,y) should switch tasks from x to y. 296 * 297 */ 298 __notrace_funcgraph struct task_struct * 299 __switch_to(struct task_struct *prev, struct task_struct *next) 300 { 301 struct thread_struct *next_t = &next->thread; 302 303 unlazy_fpu(prev, task_pt_regs(prev)); 304 305 /* we're going to use this soon, after a few expensive things */ 306 if (next->fpu_counter > 5) 307 prefetch(&next_t->fpu.hard); 308 309 #ifdef CONFIG_MMU 310 /* 311 * Restore the kernel mode register 312 * k7 (r7_bank1) 313 */ 314 asm volatile("ldc %0, r7_bank" 315 : /* no output */ 316 : "r" (task_thread_info(next))); 317 #endif 318 319 /* If no tasks are using the UBC, we're done */ 320 if (ubc_usercnt == 0) 321 /* If no tasks are using the UBC, we're done */; 322 else if (next->thread.ubc_pc && next->mm) { 323 int asid = 0; 324 #ifdef CONFIG_MMU 325 asid |= cpu_asid(smp_processor_id(), next->mm); 326 #endif 327 ubc_set_tracing(asid, next->thread.ubc_pc); 328 } else { 329 #if defined(CONFIG_CPU_SH4A) 330 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 331 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 332 #else 333 ctrl_outw(0, UBC_BBRA); 334 ctrl_outw(0, UBC_BBRB); 335 #endif 336 } 337 338 /* 339 * If the task has used fpu the last 5 timeslices, just do a full 340 * restore of the math state immediately to avoid the trap; the 341 * chances of needing FPU soon are obviously high now 342 */ 343 if (next->fpu_counter > 5) 344 fpu_state_restore(task_pt_regs(next)); 345 346 return prev; 347 } 348 349 asmlinkage int sys_fork(unsigned long r4, unsigned long r5, 350 unsigned long r6, unsigned long r7, 351 struct pt_regs __regs) 352 { 353 #ifdef CONFIG_MMU 354 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 355 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); 356 #else 357 /* fork almost works, enough to trick you into looking elsewhere :-( */ 358 return -EINVAL; 359 #endif 360 } 361 362 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, 363 unsigned long parent_tidptr, 364 unsigned long child_tidptr, 365 struct pt_regs __regs) 366 { 367 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 368 if (!newsp) 369 newsp = regs->regs[15]; 370 return do_fork(clone_flags, newsp, regs, 0, 371 (int __user *)parent_tidptr, 372 (int __user *)child_tidptr); 373 } 374 375 /* 376 * This is trivial, and on the face of it looks like it 377 * could equally well be done in user mode. 378 * 379 * Not so, for quite unobvious reasons - register pressure. 380 * In user mode vfork() cannot have a stack frame, and if 381 * done by calling the "clone()" system call directly, you 382 * do not have enough call-clobbered registers to hold all 383 * the information you need. 384 */ 385 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, 386 unsigned long r6, unsigned long r7, 387 struct pt_regs __regs) 388 { 389 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 390 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, 391 0, NULL, NULL); 392 } 393 394 /* 395 * sys_execve() executes a new program. 396 */ 397 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv, 398 char __user * __user *uenvp, unsigned long r7, 399 struct pt_regs __regs) 400 { 401 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 402 int error; 403 char *filename; 404 405 filename = getname(ufilename); 406 error = PTR_ERR(filename); 407 if (IS_ERR(filename)) 408 goto out; 409 410 error = do_execve(filename, uargv, uenvp, regs); 411 putname(filename); 412 out: 413 return error; 414 } 415 416 unsigned long get_wchan(struct task_struct *p) 417 { 418 unsigned long pc; 419 420 if (!p || p == current || p->state == TASK_RUNNING) 421 return 0; 422 423 /* 424 * The same comment as on the Alpha applies here, too ... 425 */ 426 pc = thread_saved_pc(p); 427 428 #ifdef CONFIG_FRAME_POINTER 429 if (in_sched_functions(pc)) { 430 unsigned long schedule_frame = (unsigned long)p->thread.sp; 431 return ((unsigned long *)schedule_frame)[21]; 432 } 433 #endif 434 435 return pc; 436 } 437 438 asmlinkage void break_point_trap(void) 439 { 440 /* Clear tracing. */ 441 #if defined(CONFIG_CPU_SH4A) 442 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 443 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 444 #else 445 ctrl_outw(0, UBC_BBRA); 446 ctrl_outw(0, UBC_BBRB); 447 ctrl_outl(0, UBC_BRCR); 448 #endif 449 current->thread.ubc_pc = 0; 450 ubc_usercnt -= 1; 451 452 force_sig(SIGTRAP, current); 453 } 454