arch/sh/kernel/process_64.c

   1 /*
   2  * arch/sh/kernel/process_64.c
   3  *
   4  * This file handles the architecture-dependent parts of process handling..
   5  *
   6  * Copyright (C) 2000, 2001  Paolo Alberelli
   7  * Copyright (C) 2003 - 2007  Paul Mundt
   8  * Copyright (C) 2003, 2004 Richard Curnow
   9  *
  10  * Started from SH3/4 version:
  11  *   Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
  12  *
  13  *   In turn started from i386 version:
  14  *     Copyright (C) 1995  Linus Torvalds
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License.  See the file "COPYING" in the main directory of this archive
  18  * for more details.
  19  */
  20 #include <linux/mm.h>
  21 #include <linux/fs.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/reboot.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/io.h>
  28 #include <asm/syscalls.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/pgtable.h>
  31 #include <asm/mmu_context.h>
  32 #include <asm/fpu.h>
  33 #include <asm/switch_to.h>
  34
  35 struct task_struct *last_task_used_math = NULL;
  36 struct pt_regs fake_swapper_regs = { 0, };
  37
  38 void show_regs(struct pt_regs *regs)
  39 {
  40         unsigned long long ah, al, bh, bl, ch, cl;
  41
  42         printk("\n");
  43         show_regs_print_info(KERN_DEFAULT);
  44
  45         ah = (regs->pc) >> 32;
  46         al = (regs->pc) & 0xffffffff;
  47         bh = (regs->regs[18]) >> 32;
  48         bl = (regs->regs[18]) & 0xffffffff;
  49         ch = (regs->regs[15]) >> 32;
  50         cl = (regs->regs[15]) & 0xffffffff;
  51         printk("PC  : %08Lx%08Lx LINK: %08Lx%08Lx SP  : %08Lx%08Lx\n",
  52                ah, al, bh, bl, ch, cl);
  53
  54         ah = (regs->sr) >> 32;
  55         al = (regs->sr) & 0xffffffff;
  56         asm volatile ("getcon   " __TEA ", %0" : "=r" (bh));
  57         asm volatile ("getcon   " __TEA ", %0" : "=r" (bl));
  58         bh = (bh) >> 32;
  59         bl = (bl) & 0xffffffff;
  60         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (ch));
  61         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (cl));
  62         ch = (ch) >> 32;
  63         cl = (cl) & 0xffffffff;
  64         printk("SR  : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
  65                ah, al, bh, bl, ch, cl);
  66
  67         ah = (regs->regs[0]) >> 32;
  68         al = (regs->regs[0]) & 0xffffffff;
  69         bh = (regs->regs[1]) >> 32;
  70         bl = (regs->regs[1]) & 0xffffffff;
  71         ch = (regs->regs[2]) >> 32;
  72         cl = (regs->regs[2]) & 0xffffffff;
  73         printk("R0  : %08Lx%08Lx R1  : %08Lx%08Lx R2  : %08Lx%08Lx\n",
  74                ah, al, bh, bl, ch, cl);
  75
  76         ah = (regs->regs[3]) >> 32;
  77         al = (regs->regs[3]) & 0xffffffff;
  78         bh = (regs->regs[4]) >> 32;
  79         bl = (regs->regs[4]) & 0xffffffff;
  80         ch = (regs->regs[5]) >> 32;
  81         cl = (regs->regs[5]) & 0xffffffff;
  82         printk("R3  : %08Lx%08Lx R4  : %08Lx%08Lx R5  : %08Lx%08Lx\n",
  83                ah, al, bh, bl, ch, cl);
  84
  85         ah = (regs->regs[6]) >> 32;
  86         al = (regs->regs[6]) & 0xffffffff;
  87         bh = (regs->regs[7]) >> 32;
  88         bl = (regs->regs[7]) & 0xffffffff;
  89         ch = (regs->regs[8]) >> 32;
  90         cl = (regs->regs[8]) & 0xffffffff;
  91         printk("R6  : %08Lx%08Lx R7  : %08Lx%08Lx R8  : %08Lx%08Lx\n",
  92                ah, al, bh, bl, ch, cl);
  93
  94         ah = (regs->regs[9]) >> 32;
  95         al = (regs->regs[9]) & 0xffffffff;
  96         bh = (regs->regs[10]) >> 32;
  97         bl = (regs->regs[10]) & 0xffffffff;
  98         ch = (regs->regs[11]) >> 32;
  99         cl = (regs->regs[11]) & 0xffffffff;
 100         printk("R9  : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
 101                ah, al, bh, bl, ch, cl);
 102
 103         ah = (regs->regs[12]) >> 32;
 104         al = (regs->regs[12]) & 0xffffffff;
 105         bh = (regs->regs[13]) >> 32;
 106         bl = (regs->regs[13]) & 0xffffffff;
 107         ch = (regs->regs[14]) >> 32;
 108         cl = (regs->regs[14]) & 0xffffffff;
 109         printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
 110                ah, al, bh, bl, ch, cl);
 111
 112         ah = (regs->regs[16]) >> 32;
 113         al = (regs->regs[16]) & 0xffffffff;
 114         bh = (regs->regs[17]) >> 32;
 115         bl = (regs->regs[17]) & 0xffffffff;
 116         ch = (regs->regs[19]) >> 32;
 117         cl = (regs->regs[19]) & 0xffffffff;
 118         printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
 119                ah, al, bh, bl, ch, cl);
 120
 121         ah = (regs->regs[20]) >> 32;
 122         al = (regs->regs[20]) & 0xffffffff;
 123         bh = (regs->regs[21]) >> 32;
 124         bl = (regs->regs[21]) & 0xffffffff;
 125         ch = (regs->regs[22]) >> 32;
 126         cl = (regs->regs[22]) & 0xffffffff;
 127         printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
 128                ah, al, bh, bl, ch, cl);
 129
 130         ah = (regs->regs[23]) >> 32;
 131         al = (regs->regs[23]) & 0xffffffff;
 132         bh = (regs->regs[24]) >> 32;
 133         bl = (regs->regs[24]) & 0xffffffff;
 134         ch = (regs->regs[25]) >> 32;
 135         cl = (regs->regs[25]) & 0xffffffff;
 136         printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
 137                ah, al, bh, bl, ch, cl);
 138
 139         ah = (regs->regs[26]) >> 32;
 140         al = (regs->regs[26]) & 0xffffffff;
 141         bh = (regs->regs[27]) >> 32;
 142         bl = (regs->regs[27]) & 0xffffffff;
 143         ch = (regs->regs[28]) >> 32;
 144         cl = (regs->regs[28]) & 0xffffffff;
 145         printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
 146                ah, al, bh, bl, ch, cl);
 147
 148         ah = (regs->regs[29]) >> 32;
 149         al = (regs->regs[29]) & 0xffffffff;
 150         bh = (regs->regs[30]) >> 32;
 151         bl = (regs->regs[30]) & 0xffffffff;
 152         ch = (regs->regs[31]) >> 32;
 153         cl = (regs->regs[31]) & 0xffffffff;
 154         printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
 155                ah, al, bh, bl, ch, cl);
 156
 157         ah = (regs->regs[32]) >> 32;
 158         al = (regs->regs[32]) & 0xffffffff;
 159         bh = (regs->regs[33]) >> 32;
 160         bl = (regs->regs[33]) & 0xffffffff;
 161         ch = (regs->regs[34]) >> 32;
 162         cl = (regs->regs[34]) & 0xffffffff;
 163         printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
 164                ah, al, bh, bl, ch, cl);
 165
 166         ah = (regs->regs[35]) >> 32;
 167         al = (regs->regs[35]) & 0xffffffff;
 168         bh = (regs->regs[36]) >> 32;
 169         bl = (regs->regs[36]) & 0xffffffff;
 170         ch = (regs->regs[37]) >> 32;
 171         cl = (regs->regs[37]) & 0xffffffff;
 172         printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
 173                ah, al, bh, bl, ch, cl);
 174
 175         ah = (regs->regs[38]) >> 32;
 176         al = (regs->regs[38]) & 0xffffffff;
 177         bh = (regs->regs[39]) >> 32;
 178         bl = (regs->regs[39]) & 0xffffffff;
 179         ch = (regs->regs[40]) >> 32;
 180         cl = (regs->regs[40]) & 0xffffffff;
 181         printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
 182                ah, al, bh, bl, ch, cl);
 183
 184         ah = (regs->regs[41]) >> 32;
 185         al = (regs->regs[41]) & 0xffffffff;
 186         bh = (regs->regs[42]) >> 32;
 187         bl = (regs->regs[42]) & 0xffffffff;
 188         ch = (regs->regs[43]) >> 32;
 189         cl = (regs->regs[43]) & 0xffffffff;
 190         printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
 191                ah, al, bh, bl, ch, cl);
 192
 193         ah = (regs->regs[44]) >> 32;
 194         al = (regs->regs[44]) & 0xffffffff;
 195         bh = (regs->regs[45]) >> 32;
 196         bl = (regs->regs[45]) & 0xffffffff;
 197         ch = (regs->regs[46]) >> 32;
 198         cl = (regs->regs[46]) & 0xffffffff;
 199         printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
 200                ah, al, bh, bl, ch, cl);
 201
 202         ah = (regs->regs[47]) >> 32;
 203         al = (regs->regs[47]) & 0xffffffff;
 204         bh = (regs->regs[48]) >> 32;
 205         bl = (regs->regs[48]) & 0xffffffff;
 206         ch = (regs->regs[49]) >> 32;
 207         cl = (regs->regs[49]) & 0xffffffff;
 208         printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
 209                ah, al, bh, bl, ch, cl);
 210
 211         ah = (regs->regs[50]) >> 32;
 212         al = (regs->regs[50]) & 0xffffffff;
 213         bh = (regs->regs[51]) >> 32;
 214         bl = (regs->regs[51]) & 0xffffffff;
 215         ch = (regs->regs[52]) >> 32;
 216         cl = (regs->regs[52]) & 0xffffffff;
 217         printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
 218                ah, al, bh, bl, ch, cl);
 219
 220         ah = (regs->regs[53]) >> 32;
 221         al = (regs->regs[53]) & 0xffffffff;
 222         bh = (regs->regs[54]) >> 32;
 223         bl = (regs->regs[54]) & 0xffffffff;
 224         ch = (regs->regs[55]) >> 32;
 225         cl = (regs->regs[55]) & 0xffffffff;
 226         printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
 227                ah, al, bh, bl, ch, cl);
 228
 229         ah = (regs->regs[56]) >> 32;
 230         al = (regs->regs[56]) & 0xffffffff;
 231         bh = (regs->regs[57]) >> 32;
 232         bl = (regs->regs[57]) & 0xffffffff;
 233         ch = (regs->regs[58]) >> 32;
 234         cl = (regs->regs[58]) & 0xffffffff;
 235         printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
 236                ah, al, bh, bl, ch, cl);
 237
 238         ah = (regs->regs[59]) >> 32;
 239         al = (regs->regs[59]) & 0xffffffff;
 240         bh = (regs->regs[60]) >> 32;
 241         bl = (regs->regs[60]) & 0xffffffff;
 242         ch = (regs->regs[61]) >> 32;
 243         cl = (regs->regs[61]) & 0xffffffff;
 244         printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
 245                ah, al, bh, bl, ch, cl);
 246
 247         ah = (regs->regs[62]) >> 32;
 248         al = (regs->regs[62]) & 0xffffffff;
 249         bh = (regs->tregs[0]) >> 32;
 250         bl = (regs->tregs[0]) & 0xffffffff;
 251         ch = (regs->tregs[1]) >> 32;
 252         cl = (regs->tregs[1]) & 0xffffffff;
 253         printk("R62 : %08Lx%08Lx T0  : %08Lx%08Lx T1  : %08Lx%08Lx\n",
 254                ah, al, bh, bl, ch, cl);
 255
 256         ah = (regs->tregs[2]) >> 32;
 257         al = (regs->tregs[2]) & 0xffffffff;
 258         bh = (regs->tregs[3]) >> 32;
 259         bl = (regs->tregs[3]) & 0xffffffff;
 260         ch = (regs->tregs[4]) >> 32;
 261         cl = (regs->tregs[4]) & 0xffffffff;
 262         printk("T2  : %08Lx%08Lx T3  : %08Lx%08Lx T4  : %08Lx%08Lx\n",
 263                ah, al, bh, bl, ch, cl);
 264
 265         ah = (regs->tregs[5]) >> 32;
 266         al = (regs->tregs[5]) & 0xffffffff;
 267         bh = (regs->tregs[6]) >> 32;
 268         bl = (regs->tregs[6]) & 0xffffffff;
 269         ch = (regs->tregs[7]) >> 32;
 270         cl = (regs->tregs[7]) & 0xffffffff;
 271         printk("T5  : %08Lx%08Lx T6  : %08Lx%08Lx T7  : %08Lx%08Lx\n",
 272                ah, al, bh, bl, ch, cl);
 273
 274         /*
 275          * If we're in kernel mode, dump the stack too..
 276          */
 277         if (!user_mode(regs)) {
 278                 void show_stack(struct task_struct *tsk, unsigned long *sp);
 279                 unsigned long sp = regs->regs[15] & 0xffffffff;
 280                 struct task_struct *tsk = get_current();
 281
 282                 tsk->thread.kregs = regs;
 283
 284                 show_stack(tsk, (unsigned long *)sp);
 285         }
 286 }
 287
 288 /*
 289  * Free current thread data structures etc..
 290  */
 291 void exit_thread(void)
 292 {
 293         /*
 294          * See arch/sparc/kernel/process.c for the precedent for doing
 295          * this -- RPC.
 296          *
 297          * The SH-5 FPU save/restore approach relies on
 298          * last_task_used_math pointing to a live task_struct.  When
 299          * another task tries to use the FPU for the 1st time, the FPUDIS
 300          * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
 301          * existing FPU state to the FP regs field within
 302          * last_task_used_math before re-loading the new task's FPU state
 303          * (or initialising it if the FPU has been used before).  So if
 304          * last_task_used_math is stale, and its page has already been
 305          * re-allocated for another use, the consequences are rather
 306          * grim. Unless we null it here, there is no other path through
 307          * which it would get safely nulled.
 308          */
 309 #ifdef CONFIG_SH_FPU
 310         if (last_task_used_math == current) {
 311                 last_task_used_math = NULL;
 312         }
 313 #endif
 314 }
 315
 316 void flush_thread(void)
 317 {
 318
 319         /* Called by fs/exec.c (setup_new_exec) to remove traces of a
 320          * previously running executable. */
 321 #ifdef CONFIG_SH_FPU
 322         if (last_task_used_math == current) {
 323                 last_task_used_math = NULL;
 324         }
 325         /* Force FPU state to be reinitialised after exec */
 326         clear_used_math();
 327 #endif
 328
 329         /* if we are a kernel thread, about to change to user thread,
 330          * update kreg
 331          */
 332         if(current->thread.kregs==&fake_swapper_regs) {
 333           current->thread.kregs =
 334              ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
 335           current->thread.uregs = current->thread.kregs;
 336         }
 337 }
 338
 339 void release_thread(struct task_struct *dead_task)
 340 {
 341         /* do nothing */
 342 }
 343
 344 /* Fill in the fpu structure for a core dump.. */
 345 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 346 {
 347 #ifdef CONFIG_SH_FPU
 348         int fpvalid;
 349         struct task_struct *tsk = current;
 350
 351         fpvalid = !!tsk_used_math(tsk);
 352         if (fpvalid) {
 353                 if (current == last_task_used_math) {
 354                         enable_fpu();
 355                         save_fpu(tsk);
 356                         disable_fpu();
 357                         last_task_used_math = 0;
 358                         regs->sr |= SR_FD;
 359                 }
 360
 361                 memcpy(fpu, &tsk->thread.xstate->hardfpu, sizeof(*fpu));
 362         }
 363
 364         return fpvalid;
 365 #else
 366         return 0; /* Task didn't use the fpu at all. */
 367 #endif
 368 }
 369 EXPORT_SYMBOL(dump_fpu);
 370
 371 asmlinkage void ret_from_fork(void);
 372 asmlinkage void ret_from_kernel_thread(void);
 373
 374 int copy_thread(unsigned long clone_flags, unsigned long usp,
 375                 unsigned long arg, struct task_struct *p)
 376 {
 377         struct pt_regs *childregs, *regs = current_pt_regs();
 378
 379 #ifdef CONFIG_SH_FPU
 380         /* can't happen for a kernel thread */
 381         if (last_task_used_math == current) {
 382                 enable_fpu();
 383                 save_fpu(current);
 384                 disable_fpu();
 385                 last_task_used_math = NULL;
 386                 current_pt_regs()->sr |= SR_FD;
 387         }
 388 #endif
 389         /* Copy from sh version */
 390         childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
 391         p->thread.sp = (unsigned long) childregs;
 392
 393         if (unlikely(p->flags & PF_KTHREAD)) {
 394                 memset(childregs, 0, sizeof(struct pt_regs));
 395                 childregs->regs[2] = (unsigned long)arg;
 396                 childregs->regs[3] = (unsigned long)fn;
 397                 childregs->sr = (1 << 30); /* not user_mode */
 398                 childregs->sr |= SR_FD; /* Invalidate FPU flag */
 399                 p->thread.pc = (unsigned long) ret_from_kernel_thread;
 400                 return 0;
 401         }
 402         *childregs = *current_pt_regs();
 403
 404         /*
 405          * Sign extend the edited stack.
 406          * Note that thread.pc and thread.pc will stay
 407          * 32-bit wide and context switch must take care
 408          * of NEFF sign extension.
 409          */
 410         if (usp)
 411                 childregs->regs[15] = neff_sign_extend(usp);
 412         p->thread.uregs = childregs;
 413
 414         childregs->regs[9] = 0; /* Set return value for child */
 415         childregs->sr |= SR_FD; /* Invalidate FPU flag */
 416
 417         p->thread.pc = (unsigned long) ret_from_fork;
 418
 419         return 0;
 420 }
 421
 422 #ifdef CONFIG_FRAME_POINTER
 423 static int in_sh64_switch_to(unsigned long pc)
 424 {
 425         extern char __sh64_switch_to_end;
 426         /* For a sleeping task, the PC is somewhere in the middle of the function,
 427            so we don't have to worry about masking the LSB off */
 428         return (pc >= (unsigned long) sh64_switch_to) &&
 429                (pc < (unsigned long) &__sh64_switch_to_end);
 430 }
 431 #endif
 432
 433 unsigned long get_wchan(struct task_struct *p)
 434 {
 435         unsigned long pc;
 436
 437         if (!p || p == current || p->state == TASK_RUNNING)
 438                 return 0;
 439
 440         /*
 441          * The same comment as on the Alpha applies here, too ...
 442          */
 443         pc = thread_saved_pc(p);
 444
 445 #ifdef CONFIG_FRAME_POINTER
 446         if (in_sh64_switch_to(pc)) {
 447                 unsigned long schedule_fp;
 448                 unsigned long sh64_switch_to_fp;
 449                 unsigned long schedule_caller_pc;
 450
 451                 sh64_switch_to_fp = (long) p->thread.sp;
 452                 /* r14 is saved at offset 4 in the sh64_switch_to frame */
 453                 schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
 454
 455                 /* and the caller of 'schedule' is (currently!) saved at offset 24
 456                    in the frame of schedule (from disasm) */
 457                 schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
 458                 return schedule_caller_pc;
 459         }
 460 #endif
 461         return pc;
 462 }