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/system.h>
  32 #include <asm/setup.h>
  33 #include <asm/pgtable.h>
  34 #include <asm/tlb.h>
  35 #include <asm/gdb-stub.h>
  36 #include <asm/mb-regs.h>
  37
  38 #include "local.h"
  39
  40 asmlinkage void ret_from_fork(void);
  41
  42 #include <asm/pgalloc.h>
  43
  44 void (*pm_power_off)(void);
  45 EXPORT_SYMBOL(pm_power_off);
  46
  47 struct task_struct *alloc_task_struct_node(int node)
  48 {
  49         struct task_struct *p = kmalloc_node(THREAD_SIZE, GFP_KERNEL, node);
  50
  51         if (p)
  52                 atomic_set((atomic_t *)(p+1), 1);
  53         return p;
  54 }
  55
  56 void free_task_struct(struct task_struct *p)
  57 {
  58         if (atomic_dec_and_test((atomic_t *)(p+1)))
  59                 kfree(p);
  60 }
  61
  62 static void core_sleep_idle(void)
  63 {
  64 #ifdef LED_DEBUG_SLEEP
  65         /* Show that we're sleeping... */
  66         __set_LEDS(0x55aa);
  67 #endif
  68         frv_cpu_core_sleep();
  69 #ifdef LED_DEBUG_SLEEP
  70         /* ... and that we woke up */
  71         __set_LEDS(0);
  72 #endif
  73         mb();
  74 }
  75
  76 void (*idle)(void) = core_sleep_idle;
  77
  78 /*
  79  * The idle thread. There's no useful work to be
  80  * done, so just try to conserve power and have a
  81  * low exit latency (ie sit in a loop waiting for
  82  * somebody to say that they'd like to reschedule)
  83  */
  84 void cpu_idle(void)
  85 {
  86         /* endless idle loop with no priority at all */
  87         while (1) {
  88                 while (!need_resched()) {
  89                         check_pgt_cache();
  90
  91                         if (!frv_dma_inprogress && idle)
  92                                 idle();
  93                 }
  94
  95                 preempt_enable_no_resched();
  96                 schedule();
  97                 preempt_disable();
  98         }
  99 }
 100
 101 void machine_restart(char * __unused)
 102 {
 103         unsigned long reset_addr;
 104 #ifdef CONFIG_GDBSTUB
 105         gdbstub_exit(0);
 106 #endif
 107
 108         if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
 109                 reset_addr = 0xfefff500;
 110         else
 111                 reset_addr = 0xfeff0500;
 112
 113         /* Software reset. */
 114         asm volatile("      dcef @(gr0,gr0),1 ! membar !"
 115                      "      sti     %1,@(%0,0) !"
 116                      "      nop ! nop ! nop ! nop ! nop ! "
 117                      "      nop ! nop ! nop ! nop ! nop ! "
 118                      "      nop ! nop ! nop ! nop ! nop ! "
 119                      "      nop ! nop ! nop ! nop ! nop ! "
 120                      : : "r" (reset_addr), "r" (1) );
 121
 122         for (;;)
 123                 ;
 124 }
 125
 126 void machine_halt(void)
 127 {
 128 #ifdef CONFIG_GDBSTUB
 129         gdbstub_exit(0);
 130 #endif
 131
 132         for (;;);
 133 }
 134
 135 void machine_power_off(void)
 136 {
 137 #ifdef CONFIG_GDBSTUB
 138         gdbstub_exit(0);
 139 #endif
 140
 141         for (;;);
 142 }
 143
 144 void flush_thread(void)
 145 {
 146         /* nothing */
 147 }
 148
 149 inline unsigned long user_stack(const struct pt_regs *regs)
 150 {
 151         while (regs->next_frame)
 152                 regs = regs->next_frame;
 153         return user_mode(regs) ? regs->sp : 0;
 154 }
 155
 156 asmlinkage int sys_fork(void)
 157 {
 158 #ifndef CONFIG_MMU
 159         /* fork almost works, enough to trick you into looking elsewhere:-( */
 160         return -EINVAL;
 161 #else
 162         return do_fork(SIGCHLD, user_stack(__frame), __frame, 0, NULL, NULL);
 163 #endif
 164 }
 165
 166 asmlinkage int sys_vfork(void)
 167 {
 168         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, user_stack(__frame), __frame, 0,
 169                        NULL, NULL);
 170 }
 171
 172 /*****************************************************************************/
 173 /*
 174  * clone a process
 175  * - tlsptr is retrieved by copy_thread()
 176  */
 177 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 178                          int __user *parent_tidptr, int __user *child_tidptr,
 179                          int __user *tlsptr)
 180 {
 181         if (!newsp)
 182                 newsp = user_stack(__frame);
 183         return do_fork(clone_flags, newsp, __frame, 0, parent_tidptr, child_tidptr);
 184 } /* end sys_clone() */
 185
 186 /*****************************************************************************/
 187 /*
 188  * This gets called before we allocate a new thread and copy
 189  * the current task into it.
 190  */
 191 void prepare_to_copy(struct task_struct *tsk)
 192 {
 193         //unlazy_fpu(tsk);
 194 } /* end prepare_to_copy() */
 195
 196 /*****************************************************************************/
 197 /*
 198  * set up the kernel stack and exception frames for a new process
 199  */
 200 int copy_thread(unsigned long clone_flags,
 201                 unsigned long usp, unsigned long topstk,
 202                 struct task_struct *p, struct pt_regs *regs)
 203 {
 204         struct pt_regs *childregs0, *childregs, *regs0;
 205
 206         regs0 = __kernel_frame0_ptr;
 207         childregs0 = (struct pt_regs *)
 208                 (task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
 209         childregs = childregs0;
 210
 211         /* set up the userspace frame (the only place that the USP is stored) */
 212         *childregs0 = *regs0;
 213
 214         childregs0->gr8         = 0;
 215         childregs0->sp          = usp;
 216         childregs0->next_frame  = NULL;
 217
 218         /* set up the return kernel frame if called from kernel_thread() */
 219         if (regs != regs0) {
 220                 childregs--;
 221                 *childregs = *regs;
 222                 childregs->sp = (unsigned long) childregs0;
 223                 childregs->next_frame = childregs0;
 224                 childregs->gr15 = (unsigned long) task_thread_info(p);
 225                 childregs->gr29 = (unsigned long) p;
 226         }
 227
 228         p->set_child_tid = p->clear_child_tid = NULL;
 229
 230         p->thread.frame  = childregs;
 231         p->thread.curr   = p;
 232         p->thread.sp     = (unsigned long) childregs;
 233         p->thread.fp     = 0;
 234         p->thread.lr     = 0;
 235         p->thread.pc     = (unsigned long) ret_from_fork;
 236         p->thread.frame0 = childregs0;
 237
 238         /* the new TLS pointer is passed in as arg #5 to sys_clone() */
 239         if (clone_flags & CLONE_SETTLS)
 240                 childregs->gr29 = childregs->gr12;
 241
 242         save_user_regs(p->thread.user);
 243
 244         return 0;
 245 } /* end copy_thread() */
 246
 247 /*
 248  * sys_execve() executes a new program.
 249  */
 250 asmlinkage int sys_execve(const char __user *name,
 251                           const char __user *const __user *argv,
 252                           const char __user *const __user *envp)
 253 {
 254         int error;
 255         char * filename;
 256
 257         filename = getname(name);
 258         error = PTR_ERR(filename);
 259         if (IS_ERR(filename))
 260                 return error;
 261         error = do_execve(filename, argv, envp, __frame);
 262         putname(filename);
 263         return error;
 264 }
 265
 266 unsigned long get_wchan(struct task_struct *p)
 267 {
 268         struct pt_regs *regs0;
 269         unsigned long fp, pc;
 270         unsigned long stack_limit;
 271         int count = 0;
 272         if (!p || p == current || p->state == TASK_RUNNING)
 273                 return 0;
 274
 275         stack_limit = (unsigned long) (p + 1);
 276         fp = p->thread.fp;
 277         regs0 = p->thread.frame0;
 278
 279         do {
 280                 if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
 281                         return 0;
 282
 283                 pc = ((unsigned long *) fp)[2];
 284
 285                 /* FIXME: This depends on the order of these functions. */
 286                 if (!in_sched_functions(pc))
 287                         return pc;
 288
 289                 fp = *(unsigned long *) fp;
 290         } while (count++ < 16);
 291
 292         return 0;
 293 }
 294
 295 unsigned long thread_saved_pc(struct task_struct *tsk)
 296 {
 297         /* Check whether the thread is blocked in resume() */
 298         if (in_sched_functions(tsk->thread.pc))
 299                 return ((unsigned long *)tsk->thread.fp)[2];
 300         else
 301                 return tsk->thread.pc;
 302 }
 303
 304 int elf_check_arch(const struct elf32_hdr *hdr)
 305 {
 306         unsigned long hsr0 = __get_HSR(0);
 307         unsigned long psr = __get_PSR();
 308
 309         if (hdr->e_machine != EM_FRV)
 310                 return 0;
 311
 312         switch (hdr->e_flags & EF_FRV_GPR_MASK) {
 313         case EF_FRV_GPR64:
 314                 if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
 315                         return 0;
 316         case EF_FRV_GPR32:
 317         case 0:
 318                 break;
 319         default:
 320                 return 0;
 321         }
 322
 323         switch (hdr->e_flags & EF_FRV_FPR_MASK) {
 324         case EF_FRV_FPR64:
 325                 if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
 326                         return 0;
 327         case EF_FRV_FPR32:
 328         case EF_FRV_FPR_NONE:
 329         case 0:
 330                 break;
 331         default:
 332                 return 0;
 333         }
 334
 335         if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
 336                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 337                     PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 338                         return 0;
 339
 340         switch (hdr->e_flags & EF_FRV_CPU_MASK) {
 341         case EF_FRV_CPU_GENERIC:
 342                 break;
 343         case EF_FRV_CPU_FR300:
 344         case EF_FRV_CPU_SIMPLE:
 345         case EF_FRV_CPU_TOMCAT:
 346         default:
 347                 return 0;
 348         case EF_FRV_CPU_FR400:
 349                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
 350                     PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 351                     PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
 352                     PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 353                         return 0;
 354                 break;
 355         case EF_FRV_CPU_FR450:
 356                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 357                         return 0;
 358                 break;
 359         case EF_FRV_CPU_FR500:
 360                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
 361                         return 0;
 362                 break;
 363         case EF_FRV_CPU_FR550:
 364                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 365                         return 0;
 366                 break;
 367         }
 368
 369         return 1;
 370 }
 371
 372 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
 373 {
 374         memcpy(fpregs,
 375                &current->thread.user->f,
 376                sizeof(current->thread.user->f));
 377         return 1;
 378 }