arch/sh/kernel/process_32.c

   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(&regs, 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                       &regs, 0, NULL, NULL);
 121
 122         return pid;
 123 }
 124
 125 /*
 126  * Free current thread data structures etc..
 127  */
 128 void exit_thread(void)
 129 {
 130         if (current->thread.ubc_pc) {
 131                 current->thread.ubc_pc = 0;
 132                 ubc_usercnt -= 1;
 133         }
 134 }
 135
 136 void flush_thread(void)
 137 {
 138 #if defined(CONFIG_SH_FPU)
 139         struct task_struct *tsk = current;
 140         /* Forget lazy FPU state */
 141         clear_fpu(tsk, task_pt_regs(tsk));
 142         clear_used_math();
 143 #endif
 144 }
 145
 146 void release_thread(struct task_struct *dead_task)
 147 {
 148         /* do nothing */
 149 }
 150
 151 /* Fill in the fpu structure for a core dump.. */
 152 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 153 {
 154         int fpvalid = 0;
 155
 156 #if defined(CONFIG_SH_FPU)
 157         struct task_struct *tsk = current;
 158
 159         fpvalid = !!tsk_used_math(tsk);
 160         if (fpvalid)
 161                 fpvalid = !fpregs_get(tsk, NULL, 0,
 162                                       sizeof(struct user_fpu_struct),
 163                                       fpu, NULL);
 164 #endif
 165
 166         return fpvalid;
 167 }
 168
 169 asmlinkage void ret_from_fork(void);
 170
 171 int copy_thread(unsigned long clone_flags, unsigned long usp,
 172                 unsigned long unused,
 173                 struct task_struct *p, struct pt_regs *regs)
 174 {
 175         struct thread_info *ti = task_thread_info(p);
 176         struct pt_regs *childregs;
 177 #if defined(CONFIG_SH_FPU) || defined(CONFIG_SH_DSP)
 178         struct task_struct *tsk = current;
 179 #endif
 180
 181 #if defined(CONFIG_SH_FPU)
 182         unlazy_fpu(tsk, regs);
 183         p->thread.fpu = tsk->thread.fpu;
 184         copy_to_stopped_child_used_math(p);
 185 #endif
 186
 187 #if defined(CONFIG_SH_DSP)
 188         if (is_dsp_enabled(tsk)) {
 189                 /* We can use the __save_dsp or just copy the struct:
 190                  * __save_dsp(p);
 191                  * p->thread.dsp_status.status |= SR_DSP
 192                  */
 193                 p->thread.dsp_status = tsk->thread.dsp_status;
 194         }
 195 #endif
 196
 197         childregs = task_pt_regs(p);
 198         *childregs = *regs;
 199
 200         if (user_mode(regs)) {
 201                 childregs->regs[15] = usp;
 202                 ti->addr_limit = USER_DS;
 203         } else {
 204                 childregs->regs[15] = (unsigned long)childregs;
 205                 ti->addr_limit = KERNEL_DS;
 206         }
 207
 208         if (clone_flags & CLONE_SETTLS)
 209                 childregs->gbr = childregs->regs[0];
 210
 211         childregs->regs[0] = 0; /* Set return value for child */
 212
 213         p->thread.sp = (unsigned long) childregs;
 214         p->thread.pc = (unsigned long) ret_from_fork;
 215
 216         p->thread.ubc_pc = 0;
 217
 218         return 0;
 219 }
 220
 221 /* Tracing by user break controller.  */
 222 static void ubc_set_tracing(int asid, unsigned long pc)
 223 {
 224 #if defined(CONFIG_CPU_SH4A)
 225         unsigned long val;
 226
 227         val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
 228         val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
 229
 230         ctrl_outl(val, UBC_CBR0);
 231         ctrl_outl(pc,  UBC_CAR0);
 232         ctrl_outl(0x0, UBC_CAMR0);
 233         ctrl_outl(0x0, UBC_CBCR);
 234
 235         val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
 236         ctrl_outl(val, UBC_CRR0);
 237
 238         /* Read UBC register that we wrote last, for checking update */
 239         val = ctrl_inl(UBC_CRR0);
 240
 241 #else   /* CONFIG_CPU_SH4A */
 242         ctrl_outl(pc, UBC_BARA);
 243
 244 #ifdef CONFIG_MMU
 245         ctrl_outb(asid, UBC_BASRA);
 246 #endif
 247
 248         ctrl_outl(0, UBC_BAMRA);
 249
 250         if (current_cpu_data.type == CPU_SH7729 ||
 251             current_cpu_data.type == CPU_SH7710 ||
 252             current_cpu_data.type == CPU_SH7712 ||
 253             current_cpu_data.type == CPU_SH7203){
 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         putname(filename);
 369 out:
 370         return error;
 371 }
 372
 373 unsigned long get_wchan(struct task_struct *p)
 374 {
 375         unsigned long pc;
 376
 377         if (!p || p == current || p->state == TASK_RUNNING)
 378                 return 0;
 379
 380         /*
 381          * The same comment as on the Alpha applies here, too ...
 382          */
 383         pc = thread_saved_pc(p);
 384
 385 #ifdef CONFIG_FRAME_POINTER
 386         if (in_sched_functions(pc)) {
 387                 unsigned long schedule_frame = (unsigned long)p->thread.sp;
 388                 return ((unsigned long *)schedule_frame)[21];
 389         }
 390 #endif
 391
 392         return pc;
 393 }
 394
 395 asmlinkage void break_point_trap(void)
 396 {
 397         /* Clear tracing.  */
 398 #if defined(CONFIG_CPU_SH4A)
 399         ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
 400         ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
 401 #else
 402         ctrl_outw(0, UBC_BBRA);
 403         ctrl_outw(0, UBC_BBRB);
 404         ctrl_outl(0, UBC_BRCR);
 405 #endif
 406         current->thread.ubc_pc = 0;
 407         ubc_usercnt -= 1;
 408
 409         force_sig(SIGTRAP, current);
 410 }