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 36 int ubc_usercnt = 0; 37 38 void machine_restart(char * __unused) 39 { 40 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */ 41 asm volatile("ldc %0, sr\n\t" 42 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001)); 43 } 44 45 void machine_halt(void) 46 { 47 local_irq_disable(); 48 49 while (1) 50 cpu_sleep(); 51 } 52 53 void machine_power_off(void) 54 { 55 if (pm_power_off) 56 pm_power_off(); 57 } 58 59 void show_regs(struct pt_regs * regs) 60 { 61 printk("\n"); 62 printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm); 63 printk("CPU : %d \t\t%s (%s %.*s)\n\n", 64 smp_processor_id(), print_tainted(), init_utsname()->release, 65 (int)strcspn(init_utsname()->version, " "), 66 init_utsname()->version); 67 68 print_symbol("PC is at %s\n", instruction_pointer(regs)); 69 print_symbol("PR is at %s\n", regs->pr); 70 71 printk("PC : %08lx SP : %08lx SR : %08lx ", 72 regs->pc, regs->regs[15], regs->sr); 73 #ifdef CONFIG_MMU 74 printk("TEA : %08x\n", ctrl_inl(MMU_TEA)); 75 #else 76 printk("\n"); 77 #endif 78 79 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n", 80 regs->regs[0],regs->regs[1], 81 regs->regs[2],regs->regs[3]); 82 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n", 83 regs->regs[4],regs->regs[5], 84 regs->regs[6],regs->regs[7]); 85 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n", 86 regs->regs[8],regs->regs[9], 87 regs->regs[10],regs->regs[11]); 88 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n", 89 regs->regs[12],regs->regs[13], 90 regs->regs[14]); 91 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", 92 regs->mach, regs->macl, regs->gbr, regs->pr); 93 94 show_trace(NULL, (unsigned long *)regs->regs[15], regs); 95 show_code(regs); 96 } 97 98 /* 99 * Create a kernel thread 100 */ 101 ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *)) 102 { 103 do_exit(fn(arg)); 104 } 105 106 /* Don't use this in BL=1(cli). Or else, CPU resets! */ 107 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 108 { 109 struct pt_regs regs; 110 int pid; 111 112 memset(®s, 0, sizeof(regs)); 113 regs.regs[4] = (unsigned long)arg; 114 regs.regs[5] = (unsigned long)fn; 115 116 regs.pc = (unsigned long)kernel_thread_helper; 117 regs.sr = (1 << 30); 118 119 /* Ok, create the new process.. */ 120 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, 121 ®s, 0, NULL, NULL); 122 123 return pid; 124 } 125 126 /* 127 * Free current thread data structures etc.. 128 */ 129 void exit_thread(void) 130 { 131 if (current->thread.ubc_pc) { 132 current->thread.ubc_pc = 0; 133 ubc_usercnt -= 1; 134 } 135 } 136 137 void flush_thread(void) 138 { 139 #if defined(CONFIG_SH_FPU) 140 struct task_struct *tsk = current; 141 /* Forget lazy FPU state */ 142 clear_fpu(tsk, task_pt_regs(tsk)); 143 clear_used_math(); 144 #endif 145 } 146 147 void release_thread(struct task_struct *dead_task) 148 { 149 /* do nothing */ 150 } 151 152 /* Fill in the fpu structure for a core dump.. */ 153 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) 154 { 155 int fpvalid = 0; 156 157 #if defined(CONFIG_SH_FPU) 158 struct task_struct *tsk = current; 159 160 fpvalid = !!tsk_used_math(tsk); 161 if (fpvalid) 162 fpvalid = !fpregs_get(tsk, NULL, 0, 163 sizeof(struct user_fpu_struct), 164 fpu, NULL); 165 #endif 166 167 return fpvalid; 168 } 169 170 asmlinkage void ret_from_fork(void); 171 172 int copy_thread(unsigned long clone_flags, unsigned long usp, 173 unsigned long unused, 174 struct task_struct *p, struct pt_regs *regs) 175 { 176 struct thread_info *ti = task_thread_info(p); 177 struct pt_regs *childregs; 178 #if defined(CONFIG_SH_FPU) || defined(CONFIG_SH_DSP) 179 struct task_struct *tsk = current; 180 #endif 181 182 #if defined(CONFIG_SH_FPU) 183 unlazy_fpu(tsk, regs); 184 p->thread.fpu = tsk->thread.fpu; 185 copy_to_stopped_child_used_math(p); 186 #endif 187 188 #if defined(CONFIG_SH_DSP) 189 if (is_dsp_enabled(tsk)) { 190 /* We can use the __save_dsp or just copy the struct: 191 * __save_dsp(p); 192 * p->thread.dsp_status.status |= SR_DSP 193 */ 194 p->thread.dsp_status = tsk->thread.dsp_status; 195 } 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 current_cpu_data.type == CPU_SH7203){ 255 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA); 256 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR); 257 } else { 258 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA); 259 ctrl_outw(BRCR_PCBA, UBC_BRCR); 260 } 261 #endif /* CONFIG_CPU_SH4A */ 262 } 263 264 /* 265 * switch_to(x,y) should switch tasks from x to y. 266 * 267 */ 268 __notrace_funcgraph struct task_struct * 269 __switch_to(struct task_struct *prev, struct task_struct *next) 270 { 271 #if defined(CONFIG_SH_FPU) 272 unlazy_fpu(prev, task_pt_regs(prev)); 273 #endif 274 275 #ifdef CONFIG_MMU 276 /* 277 * Restore the kernel mode register 278 * k7 (r7_bank1) 279 */ 280 asm volatile("ldc %0, r7_bank" 281 : /* no output */ 282 : "r" (task_thread_info(next))); 283 #endif 284 285 /* If no tasks are using the UBC, we're done */ 286 if (ubc_usercnt == 0) 287 /* If no tasks are using the UBC, we're done */; 288 else if (next->thread.ubc_pc && next->mm) { 289 int asid = 0; 290 #ifdef CONFIG_MMU 291 asid |= cpu_asid(smp_processor_id(), next->mm); 292 #endif 293 ubc_set_tracing(asid, next->thread.ubc_pc); 294 } else { 295 #if defined(CONFIG_CPU_SH4A) 296 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 297 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 298 #else 299 ctrl_outw(0, UBC_BBRA); 300 ctrl_outw(0, UBC_BBRB); 301 #endif 302 } 303 304 return prev; 305 } 306 307 asmlinkage int sys_fork(unsigned long r4, unsigned long r5, 308 unsigned long r6, unsigned long r7, 309 struct pt_regs __regs) 310 { 311 #ifdef CONFIG_MMU 312 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 313 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); 314 #else 315 /* fork almost works, enough to trick you into looking elsewhere :-( */ 316 return -EINVAL; 317 #endif 318 } 319 320 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, 321 unsigned long parent_tidptr, 322 unsigned long child_tidptr, 323 struct pt_regs __regs) 324 { 325 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 326 if (!newsp) 327 newsp = regs->regs[15]; 328 return do_fork(clone_flags, newsp, regs, 0, 329 (int __user *)parent_tidptr, 330 (int __user *)child_tidptr); 331 } 332 333 /* 334 * This is trivial, and on the face of it looks like it 335 * could equally well be done in user mode. 336 * 337 * Not so, for quite unobvious reasons - register pressure. 338 * In user mode vfork() cannot have a stack frame, and if 339 * done by calling the "clone()" system call directly, you 340 * do not have enough call-clobbered registers to hold all 341 * the information you need. 342 */ 343 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, 344 unsigned long r6, unsigned long r7, 345 struct pt_regs __regs) 346 { 347 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 348 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, 349 0, NULL, NULL); 350 } 351 352 /* 353 * sys_execve() executes a new program. 354 */ 355 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv, 356 char __user * __user *uenvp, unsigned long r7, 357 struct pt_regs __regs) 358 { 359 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 360 int error; 361 char *filename; 362 363 filename = getname(ufilename); 364 error = PTR_ERR(filename); 365 if (IS_ERR(filename)) 366 goto out; 367 368 error = do_execve(filename, uargv, uenvp, regs); 369 putname(filename); 370 out: 371 return error; 372 } 373 374 unsigned long get_wchan(struct task_struct *p) 375 { 376 unsigned long pc; 377 378 if (!p || p == current || p->state == TASK_RUNNING) 379 return 0; 380 381 /* 382 * The same comment as on the Alpha applies here, too ... 383 */ 384 pc = thread_saved_pc(p); 385 386 #ifdef CONFIG_FRAME_POINTER 387 if (in_sched_functions(pc)) { 388 unsigned long schedule_frame = (unsigned long)p->thread.sp; 389 return ((unsigned long *)schedule_frame)[21]; 390 } 391 #endif 392 393 return pc; 394 } 395 396 asmlinkage void break_point_trap(void) 397 { 398 /* Clear tracing. */ 399 #if defined(CONFIG_CPU_SH4A) 400 ctrl_outl(UBC_CBR_INIT, UBC_CBR0); 401 ctrl_outl(UBC_CRR_INIT, UBC_CRR0); 402 #else 403 ctrl_outw(0, UBC_BBRA); 404 ctrl_outw(0, UBC_BBRB); 405 ctrl_outl(0, UBC_BRCR); 406 #endif 407 current->thread.ubc_pc = 0; 408 ubc_usercnt -= 1; 409 410 force_sig(SIGTRAP, current); 411 } 412