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 #include <linux/rcupdate.h>
  29
  30 #include <asm/asm-offsets.h>
  31 #include <asm/uaccess.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 asmlinkage void ret_from_kernel_thread(void);
  42
  43 #include <asm/pgalloc.h>
  44
  45 void (*pm_power_off)(void);
  46 EXPORT_SYMBOL(pm_power_off);
  47
  48 static void core_sleep_idle(void)
  49 {
  50 #ifdef LED_DEBUG_SLEEP
  51         /* Show that we're sleeping... */
  52         __set_LEDS(0x55aa);
  53 #endif
  54         frv_cpu_core_sleep();
  55 #ifdef LED_DEBUG_SLEEP
  56         /* ... and that we woke up */
  57         __set_LEDS(0);
  58 #endif
  59         mb();
  60 }
  61
  62 void arch_cpu_idle(void)
  63 {
  64         if (!frv_dma_inprogress)
  65                 core_sleep_idle();
  66         else
  67                 local_irq_enable();
  68 }
  69
  70 void machine_restart(char * __unused)
  71 {
  72         unsigned long reset_addr;
  73 #ifdef CONFIG_GDBSTUB
  74         gdbstub_exit(0);
  75 #endif
  76
  77         if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
  78                 reset_addr = 0xfefff500;
  79         else
  80                 reset_addr = 0xfeff0500;
  81
  82         /* Software reset. */
  83         asm volatile("      dcef @(gr0,gr0),1 ! membar !"
  84                      "      sti     %1,@(%0,0) !"
  85                      "      nop ! nop ! nop ! nop ! nop ! "
  86                      "      nop ! nop ! nop ! nop ! nop ! "
  87                      "      nop ! nop ! nop ! nop ! nop ! "
  88                      "      nop ! nop ! nop ! nop ! nop ! "
  89                      : : "r" (reset_addr), "r" (1) );
  90
  91         for (;;)
  92                 ;
  93 }
  94
  95 void machine_halt(void)
  96 {
  97 #ifdef CONFIG_GDBSTUB
  98         gdbstub_exit(0);
  99 #endif
 100
 101         for (;;);
 102 }
 103
 104 void machine_power_off(void)
 105 {
 106 #ifdef CONFIG_GDBSTUB
 107         gdbstub_exit(0);
 108 #endif
 109
 110         for (;;);
 111 }
 112
 113 void flush_thread(void)
 114 {
 115         /* nothing */
 116 }
 117
 118 inline unsigned long user_stack(const struct pt_regs *regs)
 119 {
 120         while (regs->next_frame)
 121                 regs = regs->next_frame;
 122         return user_mode(regs) ? regs->sp : 0;
 123 }
 124
 125 /*
 126  * set up the kernel stack and exception frames for a new process
 127  */
 128 int copy_thread(unsigned long clone_flags,
 129                 unsigned long usp, unsigned long arg,
 130                 struct task_struct *p)
 131 {
 132         struct pt_regs *childregs;
 133
 134         childregs = (struct pt_regs *)
 135                 (task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
 136
 137         /* set up the userspace frame (the only place that the USP is stored) */
 138         *childregs = *current_pt_regs();
 139
 140         p->thread.frame  = childregs;
 141         p->thread.curr   = p;
 142         p->thread.sp     = (unsigned long) childregs;
 143         p->thread.fp     = 0;
 144         p->thread.lr     = 0;
 145         p->thread.frame0 = childregs;
 146
 147         if (unlikely(p->flags & PF_KTHREAD)) {
 148                 childregs->gr9 = usp; /* function */
 149                 childregs->gr8 = arg;
 150                 p->thread.pc = (unsigned long) ret_from_kernel_thread;
 151                 save_user_regs(p->thread.user);
 152                 return 0;
 153         }
 154         if (usp)
 155                 childregs->sp = usp;
 156         childregs->next_frame   = NULL;
 157
 158         p->thread.pc = (unsigned long) ret_from_fork;
 159
 160         /* the new TLS pointer is passed in as arg #5 to sys_clone() */
 161         if (clone_flags & CLONE_SETTLS)
 162                 childregs->gr29 = childregs->gr12;
 163
 164         save_user_regs(p->thread.user);
 165
 166         return 0;
 167 } /* end copy_thread() */
 168
 169 unsigned long get_wchan(struct task_struct *p)
 170 {
 171         struct pt_regs *regs0;
 172         unsigned long fp, pc;
 173         unsigned long stack_limit;
 174         int count = 0;
 175         if (!p || p == current || p->state == TASK_RUNNING)
 176                 return 0;
 177
 178         stack_limit = (unsigned long) (p + 1);
 179         fp = p->thread.fp;
 180         regs0 = p->thread.frame0;
 181
 182         do {
 183                 if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
 184                         return 0;
 185
 186                 pc = ((unsigned long *) fp)[2];
 187
 188                 /* FIXME: This depends on the order of these functions. */
 189                 if (!in_sched_functions(pc))
 190                         return pc;
 191
 192                 fp = *(unsigned long *) fp;
 193         } while (count++ < 16);
 194
 195         return 0;
 196 }
 197
 198 unsigned long thread_saved_pc(struct task_struct *tsk)
 199 {
 200         /* Check whether the thread is blocked in resume() */
 201         if (in_sched_functions(tsk->thread.pc))
 202                 return ((unsigned long *)tsk->thread.fp)[2];
 203         else
 204                 return tsk->thread.pc;
 205 }
 206
 207 int elf_check_arch(const struct elf32_hdr *hdr)
 208 {
 209         unsigned long hsr0 = __get_HSR(0);
 210         unsigned long psr = __get_PSR();
 211
 212         if (hdr->e_machine != EM_FRV)
 213                 return 0;
 214
 215         switch (hdr->e_flags & EF_FRV_GPR_MASK) {
 216         case EF_FRV_GPR64:
 217                 if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
 218                         return 0;
 219         case EF_FRV_GPR32:
 220         case 0:
 221                 break;
 222         default:
 223                 return 0;
 224         }
 225
 226         switch (hdr->e_flags & EF_FRV_FPR_MASK) {
 227         case EF_FRV_FPR64:
 228                 if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
 229                         return 0;
 230         case EF_FRV_FPR32:
 231         case EF_FRV_FPR_NONE:
 232         case 0:
 233                 break;
 234         default:
 235                 return 0;
 236         }
 237
 238         if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
 239                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 240                     PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 241                         return 0;
 242
 243         switch (hdr->e_flags & EF_FRV_CPU_MASK) {
 244         case EF_FRV_CPU_GENERIC:
 245                 break;
 246         case EF_FRV_CPU_FR300:
 247         case EF_FRV_CPU_SIMPLE:
 248         case EF_FRV_CPU_TOMCAT:
 249         default:
 250                 return 0;
 251         case EF_FRV_CPU_FR400:
 252                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
 253                     PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 254                     PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
 255                     PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 256                         return 0;
 257                 break;
 258         case EF_FRV_CPU_FR450:
 259                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 260                         return 0;
 261                 break;
 262         case EF_FRV_CPU_FR500:
 263                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
 264                         return 0;
 265                 break;
 266         case EF_FRV_CPU_FR550:
 267                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 268                         return 0;
 269                 break;
 270         }
 271
 272         return 1;
 273 }
 274
 275 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
 276 {
 277         memcpy(fpregs,
 278                &current->thread.user->f,
 279                sizeof(current->thread.user->f));
 280         return 1;
 281 }