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/preempt.h> 27 #include <asm/uaccess.h> 28 #include <asm/mmu_context.h> 29 #include <asm/pgalloc.h> 30 #include <asm/system.h> 31 #include <asm/ubc.h> 32 #include <asm/fpu.h> 33 #include <asm/syscalls.h> 34 35 int ubc_usercnt = 0; 36 37 void machine_restart(char * __unused) 38 { 39 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */ 40 asm volatile("ldc %0, sr\n\t" 41 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001)); 42 } 43 44 void machine_halt(void) 45 { 46 local_irq_disable(); 47 48 while (1) 49 cpu_sleep(); 50 } 51 52 void machine_power_off(void) 53 { 54 if (pm_power_off) 55 pm_power_off(); 56 } 57 58 void show_regs(struct pt_regs * regs) 59 { 60 printk("\n"); 61 printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm); 62 printk("CPU : %d \t\t%s (%s %.*s)\n\n", 63 smp_processor_id(), print_tainted(), init_utsname()->release, 64 (int)strcspn(init_utsname()->version, " "), 65 init_utsname()->version); 66 67 print_symbol("PC is at %s\n", instruction_pointer(regs)); 68 print_symbol("PR is at %s\n", regs->pr); 69 70 printk("PC : %08lx SP : %08lx SR : %08lx ", 71 regs->pc, regs->regs[15], regs->sr); 72 #ifdef CONFIG_MMU 73 printk("TEA : %08x\n", ctrl_inl(MMU_TEA)); 74 #else 75 printk("\n"); 76 #endif 77 78 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n", 79 regs->regs[0],regs->regs[1], 80 regs->regs[2],regs->regs[3]); 81 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n", 82 regs->regs[4],regs->regs[5], 83 regs->regs[6],regs->regs[7]); 84 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n", 85 regs->regs[8],regs->regs[9], 86 regs->regs[10],regs->regs[11]); 87 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n", 88 regs->regs[12],regs->regs[13], 89 regs->regs[14]); 90 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", 91 regs->mach, regs->macl, regs->gbr, regs->pr); 92 93 show_trace(NULL, (unsigned long *)regs->regs[15], regs); 94 show_code(regs); 95 } 96 97 /* 98 * Create a kernel thread 99 */ 100 101 /* 102 * This is the mechanism for creating a new kernel thread. 103 * 104 */ 105 extern void kernel_thread_helper(void); 106 __asm__(".align 5\n" 107 "kernel_thread_helper:\n\t" 108 "jsr @r5\n\t" 109 " nop\n\t" 110 "mov.l 1f, r1\n\t" 111 "jsr @r1\n\t" 112 " mov r0, r4\n\t" 113 ".align 2\n\t" 114 "1:.long do_exit"); 115 116 /* Don't use this in BL=1(cli). Or else, CPU resets! */ 117 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 118 { 119 struct pt_regs regs; 120 int pid; 121 122 memset(®s, 0, sizeof(regs)); 123 regs.regs[4] = (unsigned long)arg; 124 regs.regs[5] = (unsigned long)fn; 125 126 regs.pc = (unsigned long)kernel_thread_helper; 127 regs.sr = (1 << 30); 128 129 /* Ok, create the new process.. */ 130 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, 131 ®s, 0, NULL, NULL); 132 133 trace_mark(kernel_arch_kthread_create, "pid %d fn %p", pid, fn); 134 135 return pid; 136 } 137 138 /* 139 * Free current thread data structures etc.. 140 */ 141 void exit_thread(void) 142 { 143 if (current->thread.ubc_pc) { 144 current->thread.ubc_pc = 0; 145 ubc_usercnt -= 1; 146 } 147 } 148 149 void flush_thread(void) 150 { 151 #if defined(CONFIG_SH_FPU) 152 struct task_struct *tsk = current; 153 /* Forget lazy FPU state */ 154 clear_fpu(tsk, task_pt_regs(tsk)); 155 clear_used_math(); 156 #endif 157 } 158 159 void release_thread(struct task_struct *dead_task) 160 { 161 /* do nothing */ 162 } 163 164 /* Fill in the fpu structure for a core dump.. */ 165 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) 166 { 167 int fpvalid = 0; 168 169 #if defined(CONFIG_SH_FPU) 170 struct task_struct *tsk = current; 171 172 fpvalid = !!tsk_used_math(tsk); 173 if (fpvalid) 174 fpvalid = !fpregs_get(tsk, NULL, 0, 175 sizeof(struct user_fpu_struct), 176 fpu, NULL); 177 #endif 178 179 return fpvalid; 180 } 181 182 asmlinkage void ret_from_fork(void); 183 184 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 185 unsigned long unused, 186 struct task_struct *p, struct pt_regs *regs) 187 { 188 struct thread_info *ti = task_thread_info(p); 189 struct pt_regs *childregs; 190 #if defined(CONFIG_SH_FPU) 191 struct task_struct *tsk = current; 192 193 unlazy_fpu(tsk, regs); 194 p->thread.fpu = tsk->thread.fpu; 195 copy_to_stopped_child_used_math(p); 196 #endif 197 198 childregs = task_pt_regs(p); 199 *childregs = *regs; 200 201 if (user_mode(regs)) { 202 childregs->regs[15] = usp; 203 ti->addr_limit = USER_DS; 204 } else { 205 childregs->regs[15] = (unsigned long)childregs; 206 ti->addr_limit = KERNEL_DS; 207 } 208 209 if (clone_flags & CLONE_SETTLS) 210 childregs->gbr = childregs->regs[0]; 211 212 childregs->regs[0] = 0; /* Set return value for child */ 213 214 p->thread.sp = (unsigned long) childregs; 215 p->thread.pc = (unsigned long) ret_from_fork; 216 217 p->thread.ubc_pc = 0; 218 219 return 0; 220 } 221 222 /* Tracing by user break controller. */ 223 static void ubc_set_tracing(int asid, unsigned long pc) 224 { 225 #if defined(CONFIG_CPU_SH4A) 226 unsigned long val; 227 228 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE); 229 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid)); 230 231 ctrl_outl(val, UBC_CBR0); 232 ctrl_outl(pc, UBC_CAR0); 233 ctrl_outl(0x0, UBC_CAMR0); 234 ctrl_outl(0x0, UBC_CBCR); 235 236 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE); 237 ctrl_outl(val, UBC_CRR0); 238 239 /* Read UBC register that we wrote last, for checking update */ 240 val = ctrl_inl(UBC_CRR0); 241 242 #else /* CONFIG_CPU_SH4A */ 243 ctrl_outl(pc, UBC_BARA); 244 245 #ifdef CONFIG_MMU 246 ctrl_outb(asid, UBC_BASRA); 247 #endif 248 249 ctrl_outl(0, UBC_BAMRA); 250 251 if (current_cpu_data.type == CPU_SH7729 || 252 current_cpu_data.type == CPU_SH7710 || 253 current_cpu_data.type == CPU_SH7712) { 254 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA); 255 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR); 256 } else { 257 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA); 258 ctrl_outw(BRCR_PCBA, UBC_BRCR); 259 } 260 #endif /* CONFIG_CPU_SH4A */ 261 } 262 263 /* 264 * switch_to(x,y) should switch tasks from x to y. 265 * 266 */ 267 struct task_struct *__switch_to(struct task_struct *prev, 268 struct task_struct *next) 269 { 270 #if defined(CONFIG_SH_FPU) 271 unlazy_fpu(prev, task_pt_regs(prev)); 272 #endif 273 274 #ifdef CONFIG_MMU 275 /* 276 * Restore the kernel mode register 277 * k7 (r7_bank1) 278 */ 279 asm volatile("ldc %0, r7_bank" 280 : /* no output */ 281 : "r" (task_thread_info(next))); 282 #endif 283 284 /* If no tasks are using the UBC, we're done */ 285 if (ubc_usercnt == 0) 286 /* If no tasks are using the UBC, we're done */; 287 else if (next->thread.ubc_pc && next->mm) { 288 int asid = 0; 289 #ifdef CONFIG_MMU 290 asid |= cpu_asid(smp_processor_id(), next->mm); 291 #endif 292 ubc_set_tracing(asid, next->thread.ubc_pc); 293 } else { 294 #if defined(CONFIG_CPU_SH4A) 295 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 296 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 297 #else 298 ctrl_outw(0, UBC_BBRA); 299 ctrl_outw(0, UBC_BBRB); 300 #endif 301 } 302 303 return prev; 304 } 305 306 asmlinkage int sys_fork(unsigned long r4, unsigned long r5, 307 unsigned long r6, unsigned long r7, 308 struct pt_regs __regs) 309 { 310 #ifdef CONFIG_MMU 311 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 312 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); 313 #else 314 /* fork almost works, enough to trick you into looking elsewhere :-( */ 315 return -EINVAL; 316 #endif 317 } 318 319 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, 320 unsigned long parent_tidptr, 321 unsigned long child_tidptr, 322 struct pt_regs __regs) 323 { 324 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 325 if (!newsp) 326 newsp = regs->regs[15]; 327 return do_fork(clone_flags, newsp, regs, 0, 328 (int __user *)parent_tidptr, 329 (int __user *)child_tidptr); 330 } 331 332 /* 333 * This is trivial, and on the face of it looks like it 334 * could equally well be done in user mode. 335 * 336 * Not so, for quite unobvious reasons - register pressure. 337 * In user mode vfork() cannot have a stack frame, and if 338 * done by calling the "clone()" system call directly, you 339 * do not have enough call-clobbered registers to hold all 340 * the information you need. 341 */ 342 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, 343 unsigned long r6, unsigned long r7, 344 struct pt_regs __regs) 345 { 346 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 347 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, 348 0, NULL, NULL); 349 } 350 351 /* 352 * sys_execve() executes a new program. 353 */ 354 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv, 355 char __user * __user *uenvp, unsigned long r7, 356 struct pt_regs __regs) 357 { 358 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 359 int error; 360 char *filename; 361 362 filename = getname(ufilename); 363 error = PTR_ERR(filename); 364 if (IS_ERR(filename)) 365 goto out; 366 367 error = do_execve(filename, uargv, uenvp, regs); 368 if (error == 0) { 369 task_lock(current); 370 current->ptrace &= ~PT_DTRACE; 371 task_unlock(current); 372 } 373 putname(filename); 374 out: 375 return error; 376 } 377 378 unsigned long get_wchan(struct task_struct *p) 379 { 380 unsigned long pc; 381 382 if (!p || p == current || p->state == TASK_RUNNING) 383 return 0; 384 385 /* 386 * The same comment as on the Alpha applies here, too ... 387 */ 388 pc = thread_saved_pc(p); 389 390 #ifdef CONFIG_FRAME_POINTER 391 if (in_sched_functions(pc)) { 392 unsigned long schedule_frame = (unsigned long)p->thread.sp; 393 return ((unsigned long *)schedule_frame)[21]; 394 } 395 #endif 396 397 return pc; 398 } 399 400 asmlinkage void break_point_trap(void) 401 { 402 /* Clear tracing. */ 403 #if defined(CONFIG_CPU_SH4A) 404 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 405 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 406 #else 407 ctrl_outw(0, UBC_BBRA); 408 ctrl_outw(0, UBC_BBRB); 409 #endif 410 current->thread.ubc_pc = 0; 411 ubc_usercnt -= 1; 412 413 force_sig(SIGTRAP, current); 414 } 415