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 ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *)) 101 { 102 do_exit(fn(arg)); 103 } 104 105 /* Don't use this in BL=1(cli). Or else, CPU resets! */ 106 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 107 { 108 struct pt_regs regs; 109 int pid; 110 111 memset(®s, 0, sizeof(regs)); 112 regs.regs[4] = (unsigned long)arg; 113 regs.regs[5] = (unsigned long)fn; 114 115 regs.pc = (unsigned long)kernel_thread_helper; 116 regs.sr = (1 << 30); 117 118 /* Ok, create the new process.. */ 119 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, 120 ®s, 0, NULL, NULL); 121 122 trace_mark(kernel_arch_kthread_create, "pid %d fn %p", pid, fn); 123 124 return pid; 125 } 126 127 /* 128 * Free current thread data structures etc.. 129 */ 130 void exit_thread(void) 131 { 132 if (current->thread.ubc_pc) { 133 current->thread.ubc_pc = 0; 134 ubc_usercnt -= 1; 135 } 136 } 137 138 void flush_thread(void) 139 { 140 #if defined(CONFIG_SH_FPU) 141 struct task_struct *tsk = current; 142 /* Forget lazy FPU state */ 143 clear_fpu(tsk, task_pt_regs(tsk)); 144 clear_used_math(); 145 #endif 146 } 147 148 void release_thread(struct task_struct *dead_task) 149 { 150 /* do nothing */ 151 } 152 153 /* Fill in the fpu structure for a core dump.. */ 154 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) 155 { 156 int fpvalid = 0; 157 158 #if defined(CONFIG_SH_FPU) 159 struct task_struct *tsk = current; 160 161 fpvalid = !!tsk_used_math(tsk); 162 if (fpvalid) 163 fpvalid = !fpregs_get(tsk, NULL, 0, 164 sizeof(struct user_fpu_struct), 165 fpu, NULL); 166 #endif 167 168 return fpvalid; 169 } 170 171 asmlinkage void ret_from_fork(void); 172 173 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 174 unsigned long unused, 175 struct task_struct *p, struct pt_regs *regs) 176 { 177 struct thread_info *ti = task_thread_info(p); 178 struct pt_regs *childregs; 179 #if defined(CONFIG_SH_FPU) 180 struct task_struct *tsk = current; 181 182 unlazy_fpu(tsk, regs); 183 p->thread.fpu = tsk->thread.fpu; 184 copy_to_stopped_child_used_math(p); 185 #endif 186 187 childregs = task_pt_regs(p); 188 *childregs = *regs; 189 190 if (user_mode(regs)) { 191 childregs->regs[15] = usp; 192 ti->addr_limit = USER_DS; 193 } else { 194 childregs->regs[15] = (unsigned long)childregs; 195 ti->addr_limit = KERNEL_DS; 196 } 197 198 if (clone_flags & CLONE_SETTLS) 199 childregs->gbr = childregs->regs[0]; 200 201 childregs->regs[0] = 0; /* Set return value for child */ 202 203 p->thread.sp = (unsigned long) childregs; 204 p->thread.pc = (unsigned long) ret_from_fork; 205 206 p->thread.ubc_pc = 0; 207 208 return 0; 209 } 210 211 /* Tracing by user break controller. */ 212 static void ubc_set_tracing(int asid, unsigned long pc) 213 { 214 #if defined(CONFIG_CPU_SH4A) 215 unsigned long val; 216 217 val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE); 218 val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid)); 219 220 ctrl_outl(val, UBC_CBR0); 221 ctrl_outl(pc, UBC_CAR0); 222 ctrl_outl(0x0, UBC_CAMR0); 223 ctrl_outl(0x0, UBC_CBCR); 224 225 val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE); 226 ctrl_outl(val, UBC_CRR0); 227 228 /* Read UBC register that we wrote last, for checking update */ 229 val = ctrl_inl(UBC_CRR0); 230 231 #else /* CONFIG_CPU_SH4A */ 232 ctrl_outl(pc, UBC_BARA); 233 234 #ifdef CONFIG_MMU 235 ctrl_outb(asid, UBC_BASRA); 236 #endif 237 238 ctrl_outl(0, UBC_BAMRA); 239 240 if (current_cpu_data.type == CPU_SH7729 || 241 current_cpu_data.type == CPU_SH7710 || 242 current_cpu_data.type == CPU_SH7712) { 243 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA); 244 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR); 245 } else { 246 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA); 247 ctrl_outw(BRCR_PCBA, UBC_BRCR); 248 } 249 #endif /* CONFIG_CPU_SH4A */ 250 } 251 252 /* 253 * switch_to(x,y) should switch tasks from x to y. 254 * 255 */ 256 struct task_struct *__switch_to(struct task_struct *prev, 257 struct task_struct *next) 258 { 259 #if defined(CONFIG_SH_FPU) 260 unlazy_fpu(prev, task_pt_regs(prev)); 261 #endif 262 263 #ifdef CONFIG_MMU 264 /* 265 * Restore the kernel mode register 266 * k7 (r7_bank1) 267 */ 268 asm volatile("ldc %0, r7_bank" 269 : /* no output */ 270 : "r" (task_thread_info(next))); 271 #endif 272 273 /* If no tasks are using the UBC, we're done */ 274 if (ubc_usercnt == 0) 275 /* If no tasks are using the UBC, we're done */; 276 else if (next->thread.ubc_pc && next->mm) { 277 int asid = 0; 278 #ifdef CONFIG_MMU 279 asid |= cpu_asid(smp_processor_id(), next->mm); 280 #endif 281 ubc_set_tracing(asid, next->thread.ubc_pc); 282 } else { 283 #if defined(CONFIG_CPU_SH4A) 284 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 285 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 286 #else 287 ctrl_outw(0, UBC_BBRA); 288 ctrl_outw(0, UBC_BBRB); 289 #endif 290 } 291 292 return prev; 293 } 294 295 asmlinkage int sys_fork(unsigned long r4, unsigned long r5, 296 unsigned long r6, unsigned long r7, 297 struct pt_regs __regs) 298 { 299 #ifdef CONFIG_MMU 300 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 301 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); 302 #else 303 /* fork almost works, enough to trick you into looking elsewhere :-( */ 304 return -EINVAL; 305 #endif 306 } 307 308 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, 309 unsigned long parent_tidptr, 310 unsigned long child_tidptr, 311 struct pt_regs __regs) 312 { 313 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 314 if (!newsp) 315 newsp = regs->regs[15]; 316 return do_fork(clone_flags, newsp, regs, 0, 317 (int __user *)parent_tidptr, 318 (int __user *)child_tidptr); 319 } 320 321 /* 322 * This is trivial, and on the face of it looks like it 323 * could equally well be done in user mode. 324 * 325 * Not so, for quite unobvious reasons - register pressure. 326 * In user mode vfork() cannot have a stack frame, and if 327 * done by calling the "clone()" system call directly, you 328 * do not have enough call-clobbered registers to hold all 329 * the information you need. 330 */ 331 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, 332 unsigned long r6, unsigned long r7, 333 struct pt_regs __regs) 334 { 335 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 336 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, 337 0, NULL, NULL); 338 } 339 340 /* 341 * sys_execve() executes a new program. 342 */ 343 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv, 344 char __user * __user *uenvp, unsigned long r7, 345 struct pt_regs __regs) 346 { 347 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 348 int error; 349 char *filename; 350 351 filename = getname(ufilename); 352 error = PTR_ERR(filename); 353 if (IS_ERR(filename)) 354 goto out; 355 356 error = do_execve(filename, uargv, uenvp, regs); 357 if (error == 0) { 358 task_lock(current); 359 current->ptrace &= ~PT_DTRACE; 360 task_unlock(current); 361 } 362 putname(filename); 363 out: 364 return error; 365 } 366 367 unsigned long get_wchan(struct task_struct *p) 368 { 369 unsigned long pc; 370 371 if (!p || p == current || p->state == TASK_RUNNING) 372 return 0; 373 374 /* 375 * The same comment as on the Alpha applies here, too ... 376 */ 377 pc = thread_saved_pc(p); 378 379 #ifdef CONFIG_FRAME_POINTER 380 if (in_sched_functions(pc)) { 381 unsigned long schedule_frame = (unsigned long)p->thread.sp; 382 return ((unsigned long *)schedule_frame)[21]; 383 } 384 #endif 385 386 return pc; 387 } 388 389 asmlinkage void break_point_trap(void) 390 { 391 /* Clear tracing. */ 392 #if defined(CONFIG_CPU_SH4A) 393 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 394 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 395 #else 396 ctrl_outw(0, UBC_BBRA); 397 ctrl_outw(0, UBC_BBRB); 398 #endif 399 current->thread.ubc_pc = 0; 400 ubc_usercnt -= 1; 401 402 force_sig(SIGTRAP, current); 403 } 404