arch/frv/kernel/process.c

   1 /* process.c: FRV specific parts of process handling
   2  *
   3  * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  * - Derived from arch/m68k/kernel/process.c
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/errno.h>
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/mm.h>
  18 #include <linux/smp.h>
  19 #include <linux/smp_lock.h>
  20 #include <linux/stddef.h>
  21 #include <linux/unistd.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/slab.h>
  24 #include <linux/user.h>
  25 #include <linux/elf.h>
  26 #include <linux/reboot.h>
  27 #include <linux/interrupt.h>
  28
  29 #include <asm/uaccess.h>
  30 #include <asm/system.h>
  31 #include <asm/setup.h>
  32 #include <asm/pgtable.h>
  33 #include <asm/gdb-stub.h>
  34 #include <asm/mb-regs.h>
  35
  36 #include "local.h"
  37
  38 asmlinkage void ret_from_fork(void);
  39
  40 #include <asm/pgalloc.h>
  41
  42 struct task_struct *alloc_task_struct(void)
  43 {
  44         struct task_struct *p = kmalloc(THREAD_SIZE, GFP_KERNEL);
  45         if (p)
  46                 atomic_set((atomic_t *)(p+1), 1);
  47         return p;
  48 }
  49
  50 void free_task_struct(struct task_struct *p)
  51 {
  52         if (atomic_dec_and_test((atomic_t *)(p+1)))
  53                 kfree(p);
  54 }
  55
  56 static void core_sleep_idle(void)
  57 {
  58 #ifdef LED_DEBUG_SLEEP
  59         /* Show that we're sleeping... */
  60         __set_LEDS(0x55aa);
  61 #endif
  62         frv_cpu_core_sleep();
  63 #ifdef LED_DEBUG_SLEEP
  64         /* ... and that we woke up */
  65         __set_LEDS(0);
  66 #endif
  67         mb();
  68 }
  69
  70 void (*idle)(void) = core_sleep_idle;
  71
  72 /*
  73  * The idle thread. There's no useful work to be
  74  * done, so just try to conserve power and have a
  75  * low exit latency (ie sit in a loop waiting for
  76  * somebody to say that they'd like to reschedule)
  77  */
  78 void cpu_idle(void)
  79 {
  80         /* endless idle loop with no priority at all */
  81         while (1) {
  82                 while (!need_resched()) {
  83                         irq_stat[smp_processor_id()].idle_timestamp = jiffies;
  84
  85                         if (!frv_dma_inprogress && idle)
  86                                 idle();
  87                 }
  88
  89                 schedule();
  90         }
  91 }
  92
  93 void machine_restart(char * __unused)
  94 {
  95         unsigned long reset_addr;
  96 #ifdef CONFIG_GDBSTUB
  97         gdbstub_exit(0);
  98 #endif
  99
 100         if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
 101                 reset_addr = 0xfefff500;
 102         else
 103                 reset_addr = 0xfeff0500;
 104
 105         /* Software reset. */
 106         asm volatile("      dcef @(gr0,gr0),1 ! membar !"
 107                      "      sti     %1,@(%0,0) !"
 108                      "      nop ! nop ! nop ! nop ! nop ! "
 109                      "      nop ! nop ! nop ! nop ! nop ! "
 110                      "      nop ! nop ! nop ! nop ! nop ! "
 111                      "      nop ! nop ! nop ! nop ! nop ! "
 112                      : : "r" (reset_addr), "r" (1) );
 113
 114         for (;;)
 115                 ;
 116 }
 117
 118 void machine_halt(void)
 119 {
 120 #ifdef CONFIG_GDBSTUB
 121         gdbstub_exit(0);
 122 #endif
 123
 124         for (;;);
 125 }
 126
 127 void machine_power_off(void)
 128 {
 129 #ifdef CONFIG_GDBSTUB
 130         gdbstub_exit(0);
 131 #endif
 132
 133         for (;;);
 134 }
 135
 136 void flush_thread(void)
 137 {
 138 #if 0 //ndef NO_FPU
 139         unsigned long zero = 0;
 140 #endif
 141         set_fs(USER_DS);
 142 }
 143
 144 inline unsigned long user_stack(const struct pt_regs *regs)
 145 {
 146         while (regs->next_frame)
 147                 regs = regs->next_frame;
 148         return user_mode(regs) ? regs->sp : 0;
 149 }
 150
 151 asmlinkage int sys_fork(void)
 152 {
 153 #ifndef CONFIG_MMU
 154         /* fork almost works, enough to trick you into looking elsewhere:-( */
 155         return -EINVAL;
 156 #else
 157         return do_fork(SIGCHLD, user_stack(__frame), __frame, 0, NULL, NULL);
 158 #endif
 159 }
 160
 161 asmlinkage int sys_vfork(void)
 162 {
 163         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, user_stack(__frame), __frame, 0,
 164                        NULL, NULL);
 165 }
 166
 167 /*****************************************************************************/
 168 /*
 169  * clone a process
 170  * - tlsptr is retrieved by copy_thread()
 171  */
 172 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 173                          int __user *parent_tidptr, int __user *child_tidptr,
 174                          int __user *tlsptr)
 175 {
 176         if (!newsp)
 177                 newsp = user_stack(__frame);
 178         return do_fork(clone_flags, newsp, __frame, 0, parent_tidptr, child_tidptr);
 179 } /* end sys_clone() */
 180
 181 /*****************************************************************************/
 182 /*
 183  * This gets called before we allocate a new thread and copy
 184  * the current task into it.
 185  */
 186 void prepare_to_copy(struct task_struct *tsk)
 187 {
 188         //unlazy_fpu(tsk);
 189 } /* end prepare_to_copy() */
 190
 191 /*****************************************************************************/
 192 /*
 193  * set up the kernel stack and exception frames for a new process
 194  */
 195 int copy_thread(int nr, unsigned long clone_flags,
 196                 unsigned long usp, unsigned long topstk,
 197                 struct task_struct *p, struct pt_regs *regs)
 198 {
 199         struct pt_regs *childregs0, *childregs, *regs0;
 200
 201         regs0 = __kernel_frame0_ptr;
 202         childregs0 = (struct pt_regs *)
 203                 ((unsigned long) p->thread_info + THREAD_SIZE - USER_CONTEXT_SIZE);
 204         childregs = childregs0;
 205
 206         /* set up the userspace frame (the only place that the USP is stored) */
 207         *childregs0 = *regs0;
 208
 209         childregs0->gr8         = 0;
 210         childregs0->sp          = usp;
 211         childregs0->next_frame  = NULL;
 212
 213         /* set up the return kernel frame if called from kernel_thread() */
 214         if (regs != regs0) {
 215                 childregs--;
 216                 *childregs = *regs;
 217                 childregs->sp = (unsigned long) childregs0;
 218                 childregs->next_frame = childregs0;
 219                 childregs->gr15 = (unsigned long) p->thread_info;
 220                 childregs->gr29 = (unsigned long) p;
 221         }
 222
 223         p->set_child_tid = p->clear_child_tid = NULL;
 224
 225         p->thread.frame  = childregs;
 226         p->thread.curr   = p;
 227         p->thread.sp     = (unsigned long) childregs;
 228         p->thread.fp     = 0;
 229         p->thread.lr     = 0;
 230         p->thread.pc     = (unsigned long) ret_from_fork;
 231         p->thread.frame0 = childregs0;
 232
 233         /* the new TLS pointer is passed in as arg #5 to sys_clone() */
 234         if (clone_flags & CLONE_SETTLS)
 235                 childregs->gr29 = childregs->gr12;
 236
 237         save_user_regs(p->thread.user);
 238
 239         return 0;
 240 } /* end copy_thread() */
 241
 242 /*
 243  * fill in the user structure for a core dump..
 244  */
 245 void dump_thread(struct pt_regs *regs, struct user *dump)
 246 {
 247 #if 0
 248         /* changed the size calculations - should hopefully work better. lbt */
 249         dump->magic = CMAGIC;
 250         dump->start_code = 0;
 251         dump->start_stack = user_stack(regs) & ~(PAGE_SIZE - 1);
 252         dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
 253         dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
 254         dump->u_dsize -= dump->u_tsize;
 255         dump->u_ssize = 0;
 256
 257         if (dump->start_stack < TASK_SIZE)
 258                 dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
 259
 260         dump->regs = *(struct user_context *) regs;
 261 #endif
 262 }
 263
 264 /*
 265  * sys_execve() executes a new program.
 266  */
 267 asmlinkage int sys_execve(char *name, char **argv, char **envp)
 268 {
 269         int error;
 270         char * filename;
 271
 272         lock_kernel();
 273         filename = getname(name);
 274         error = PTR_ERR(filename);
 275         if (IS_ERR(filename))
 276                 goto out;
 277         error = do_execve(filename, argv, envp, __frame);
 278         putname(filename);
 279  out:
 280         unlock_kernel();
 281         return error;
 282 }
 283
 284 unsigned long get_wchan(struct task_struct *p)
 285 {
 286         struct pt_regs *regs0;
 287         unsigned long fp, pc;
 288         unsigned long stack_limit;
 289         int count = 0;
 290         if (!p || p == current || p->state == TASK_RUNNING)
 291                 return 0;
 292
 293         stack_limit = (unsigned long) (p + 1);
 294         fp = p->thread.fp;
 295         regs0 = p->thread.frame0;
 296
 297         do {
 298                 if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
 299                         return 0;
 300
 301                 pc = ((unsigned long *) fp)[2];
 302
 303                 /* FIXME: This depends on the order of these functions. */
 304                 if (!in_sched_functions(pc))
 305                         return pc;
 306
 307                 fp = *(unsigned long *) fp;
 308         } while (count++ < 16);
 309
 310         return 0;
 311 }
 312
 313 unsigned long thread_saved_pc(struct task_struct *tsk)
 314 {
 315         /* Check whether the thread is blocked in resume() */
 316         if (in_sched_functions(tsk->thread.pc))
 317                 return ((unsigned long *)tsk->thread.fp)[2];
 318         else
 319                 return tsk->thread.pc;
 320 }
 321
 322 int elf_check_arch(const struct elf32_hdr *hdr)
 323 {
 324         unsigned long hsr0 = __get_HSR(0);
 325         unsigned long psr = __get_PSR();
 326
 327         if (hdr->e_machine != EM_FRV)
 328                 return 0;
 329
 330         switch (hdr->e_flags & EF_FRV_GPR_MASK) {
 331         case EF_FRV_GPR64:
 332                 if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
 333                         return 0;
 334         case EF_FRV_GPR32:
 335         case 0:
 336                 break;
 337         default:
 338                 return 0;
 339         }
 340
 341         switch (hdr->e_flags & EF_FRV_FPR_MASK) {
 342         case EF_FRV_FPR64:
 343                 if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
 344                         return 0;
 345         case EF_FRV_FPR32:
 346         case EF_FRV_FPR_NONE:
 347         case 0:
 348                 break;
 349         default:
 350                 return 0;
 351         }
 352
 353         if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
 354                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 355                     PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 356                         return 0;
 357
 358         switch (hdr->e_flags & EF_FRV_CPU_MASK) {
 359         case EF_FRV_CPU_GENERIC:
 360                 break;
 361         case EF_FRV_CPU_FR300:
 362         case EF_FRV_CPU_SIMPLE:
 363         case EF_FRV_CPU_TOMCAT:
 364         default:
 365                 return 0;
 366         case EF_FRV_CPU_FR400:
 367                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
 368                     PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 369                     PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
 370                     PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 371                         return 0;
 372                 break;
 373         case EF_FRV_CPU_FR450:
 374                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 375                         return 0;
 376                 break;
 377         case EF_FRV_CPU_FR500:
 378                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
 379                         return 0;
 380                 break;
 381         case EF_FRV_CPU_FR550:
 382                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 383                         return 0;
 384                 break;
 385         }
 386
 387         return 1;
 388 }