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/module.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/stddef.h>
  20 #include <linux/unistd.h>
  21 #include <linux/ptrace.h>
  22 #include <linux/slab.h>
  23 #include <linux/user.h>
  24 #include <linux/elf.h>
  25 #include <linux/reboot.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/pagemap.h>
  28
  29 #include <asm/asm-offsets.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/setup.h>
  32 #include <asm/pgtable.h>
  33 #include <asm/tlb.h>
  34 #include <asm/gdb-stub.h>
  35 #include <asm/mb-regs.h>
  36
  37 #include "local.h"
  38
  39 asmlinkage void ret_from_fork(void);
  40
  41 #include <asm/pgalloc.h>
  42
  43 void (*pm_power_off)(void);
  44 EXPORT_SYMBOL(pm_power_off);
  45
  46 static void core_sleep_idle(void)
  47 {
  48 #ifdef LED_DEBUG_SLEEP
  49         /* Show that we're sleeping... */
  50         __set_LEDS(0x55aa);
  51 #endif
  52         frv_cpu_core_sleep();
  53 #ifdef LED_DEBUG_SLEEP
  54         /* ... and that we woke up */
  55         __set_LEDS(0);
  56 #endif
  57         mb();
  58 }
  59
  60 void (*idle)(void) = core_sleep_idle;
  61
  62 /*
  63  * The idle thread. There's no useful work to be
  64  * done, so just try to conserve power and have a
  65  * low exit latency (ie sit in a loop waiting for
  66  * somebody to say that they'd like to reschedule)
  67  */
  68 void cpu_idle(void)
  69 {
  70         /* endless idle loop with no priority at all */
  71         while (1) {
  72                 while (!need_resched()) {
  73                         check_pgt_cache();
  74
  75                         if (!frv_dma_inprogress && idle)
  76                                 idle();
  77                 }
  78
  79                 schedule_preempt_disabled();
  80         }
  81 }
  82
  83 void machine_restart(char * __unused)
  84 {
  85         unsigned long reset_addr;
  86 #ifdef CONFIG_GDBSTUB
  87         gdbstub_exit(0);
  88 #endif
  89
  90         if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
  91                 reset_addr = 0xfefff500;
  92         else
  93                 reset_addr = 0xfeff0500;
  94
  95         /* Software reset. */
  96         asm volatile("      dcef @(gr0,gr0),1 ! membar !"
  97                      "      sti     %1,@(%0,0) !"
  98                      "      nop ! nop ! nop ! nop ! nop ! "
  99                      "      nop ! nop ! nop ! nop ! nop ! "
 100                      "      nop ! nop ! nop ! nop ! nop ! "
 101                      "      nop ! nop ! nop ! nop ! nop ! "
 102                      : : "r" (reset_addr), "r" (1) );
 103
 104         for (;;)
 105                 ;
 106 }
 107
 108 void machine_halt(void)
 109 {
 110 #ifdef CONFIG_GDBSTUB
 111         gdbstub_exit(0);
 112 #endif
 113
 114         for (;;);
 115 }
 116
 117 void machine_power_off(void)
 118 {
 119 #ifdef CONFIG_GDBSTUB
 120         gdbstub_exit(0);
 121 #endif
 122
 123         for (;;);
 124 }
 125
 126 void flush_thread(void)
 127 {
 128         /* nothing */
 129 }
 130
 131 inline unsigned long user_stack(const struct pt_regs *regs)
 132 {
 133         while (regs->next_frame)
 134                 regs = regs->next_frame;
 135         return user_mode(regs) ? regs->sp : 0;
 136 }
 137
 138 asmlinkage int sys_fork(void)
 139 {
 140 #ifndef CONFIG_MMU
 141         /* fork almost works, enough to trick you into looking elsewhere:-( */
 142         return -EINVAL;
 143 #else
 144         return do_fork(SIGCHLD, user_stack(__frame), __frame, 0, NULL, NULL);
 145 #endif
 146 }
 147
 148 asmlinkage int sys_vfork(void)
 149 {
 150         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, user_stack(__frame), __frame, 0,
 151                        NULL, NULL);
 152 }
 153
 154 /*****************************************************************************/
 155 /*
 156  * clone a process
 157  * - tlsptr is retrieved by copy_thread()
 158  */
 159 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 160                          int __user *parent_tidptr, int __user *child_tidptr,
 161                          int __user *tlsptr)
 162 {
 163         if (!newsp)
 164                 newsp = user_stack(__frame);
 165         return do_fork(clone_flags, newsp, __frame, 0, parent_tidptr, child_tidptr);
 166 } /* end sys_clone() */
 167
 168 /*
 169  * set up the kernel stack and exception frames for a new process
 170  */
 171 int copy_thread(unsigned long clone_flags,
 172                 unsigned long usp, unsigned long topstk,
 173                 struct task_struct *p, struct pt_regs *regs)
 174 {
 175         struct pt_regs *childregs0, *childregs, *regs0;
 176
 177         regs0 = __kernel_frame0_ptr;
 178         childregs0 = (struct pt_regs *)
 179                 (task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
 180         childregs = childregs0;
 181
 182         /* set up the userspace frame (the only place that the USP is stored) */
 183         *childregs0 = *regs0;
 184
 185         childregs0->gr8         = 0;
 186         childregs0->sp          = usp;
 187         childregs0->next_frame  = NULL;
 188
 189         /* set up the return kernel frame if called from kernel_thread() */
 190         if (regs != regs0) {
 191                 childregs--;
 192                 *childregs = *regs;
 193                 childregs->sp = (unsigned long) childregs0;
 194                 childregs->next_frame = childregs0;
 195                 childregs->gr15 = (unsigned long) task_thread_info(p);
 196                 childregs->gr29 = (unsigned long) p;
 197         }
 198
 199         p->set_child_tid = p->clear_child_tid = NULL;
 200
 201         p->thread.frame  = childregs;
 202         p->thread.curr   = p;
 203         p->thread.sp     = (unsigned long) childregs;
 204         p->thread.fp     = 0;
 205         p->thread.lr     = 0;
 206         p->thread.pc     = (unsigned long) ret_from_fork;
 207         p->thread.frame0 = childregs0;
 208
 209         /* the new TLS pointer is passed in as arg #5 to sys_clone() */
 210         if (clone_flags & CLONE_SETTLS)
 211                 childregs->gr29 = childregs->gr12;
 212
 213         save_user_regs(p->thread.user);
 214
 215         return 0;
 216 } /* end copy_thread() */
 217
 218 /*
 219  * sys_execve() executes a new program.
 220  */
 221 asmlinkage int sys_execve(const char __user *name,
 222                           const char __user *const __user *argv,
 223                           const char __user *const __user *envp)
 224 {
 225         int error;
 226         char * filename;
 227
 228         filename = getname(name);
 229         error = PTR_ERR(filename);
 230         if (IS_ERR(filename))
 231                 return error;
 232         error = do_execve(filename, argv, envp, __frame);
 233         putname(filename);
 234         return error;
 235 }
 236
 237 unsigned long get_wchan(struct task_struct *p)
 238 {
 239         struct pt_regs *regs0;
 240         unsigned long fp, pc;
 241         unsigned long stack_limit;
 242         int count = 0;
 243         if (!p || p == current || p->state == TASK_RUNNING)
 244                 return 0;
 245
 246         stack_limit = (unsigned long) (p + 1);
 247         fp = p->thread.fp;
 248         regs0 = p->thread.frame0;
 249
 250         do {
 251                 if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
 252                         return 0;
 253
 254                 pc = ((unsigned long *) fp)[2];
 255
 256                 /* FIXME: This depends on the order of these functions. */
 257                 if (!in_sched_functions(pc))
 258                         return pc;
 259
 260                 fp = *(unsigned long *) fp;
 261         } while (count++ < 16);
 262
 263         return 0;
 264 }
 265
 266 unsigned long thread_saved_pc(struct task_struct *tsk)
 267 {
 268         /* Check whether the thread is blocked in resume() */
 269         if (in_sched_functions(tsk->thread.pc))
 270                 return ((unsigned long *)tsk->thread.fp)[2];
 271         else
 272                 return tsk->thread.pc;
 273 }
 274
 275 int elf_check_arch(const struct elf32_hdr *hdr)
 276 {
 277         unsigned long hsr0 = __get_HSR(0);
 278         unsigned long psr = __get_PSR();
 279
 280         if (hdr->e_machine != EM_FRV)
 281                 return 0;
 282
 283         switch (hdr->e_flags & EF_FRV_GPR_MASK) {
 284         case EF_FRV_GPR64:
 285                 if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
 286                         return 0;
 287         case EF_FRV_GPR32:
 288         case 0:
 289                 break;
 290         default:
 291                 return 0;
 292         }
 293
 294         switch (hdr->e_flags & EF_FRV_FPR_MASK) {
 295         case EF_FRV_FPR64:
 296                 if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
 297                         return 0;
 298         case EF_FRV_FPR32:
 299         case EF_FRV_FPR_NONE:
 300         case 0:
 301                 break;
 302         default:
 303                 return 0;
 304         }
 305
 306         if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
 307                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 308                     PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 309                         return 0;
 310
 311         switch (hdr->e_flags & EF_FRV_CPU_MASK) {
 312         case EF_FRV_CPU_GENERIC:
 313                 break;
 314         case EF_FRV_CPU_FR300:
 315         case EF_FRV_CPU_SIMPLE:
 316         case EF_FRV_CPU_TOMCAT:
 317         default:
 318                 return 0;
 319         case EF_FRV_CPU_FR400:
 320                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
 321                     PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 322                     PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
 323                     PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 324                         return 0;
 325                 break;
 326         case EF_FRV_CPU_FR450:
 327                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 328                         return 0;
 329                 break;
 330         case EF_FRV_CPU_FR500:
 331                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
 332                         return 0;
 333                 break;
 334         case EF_FRV_CPU_FR550:
 335                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 336                         return 0;
 337                 break;
 338         }
 339
 340         return 1;
 341 }
 342
 343 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
 344 {
 345         memcpy(fpregs,
 346                &current->thread.user->f,
 347                sizeof(current->thread.user->f));
 348         return 1;
 349 }