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/sched/debug.h>
  17 #include <linux/sched/task.h>
  18 #include <linux/kernel.h>
  19 #include <linux/mm.h>
  20 #include <linux/smp.h>
  21 #include <linux/stddef.h>
  22 #include <linux/unistd.h>
  23 #include <linux/ptrace.h>
  24 #include <linux/slab.h>
  25 #include <linux/user.h>
  26 #include <linux/elf.h>
  27 #include <linux/reboot.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/rcupdate.h>
  31
  32 #include <asm/asm-offsets.h>
  33 #include <linux/uaccess.h>
  34 #include <asm/setup.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/tlb.h>
  37 #include <asm/gdb-stub.h>
  38 #include <asm/mb-regs.h>
  39
  40 #include "local.h"
  41
  42 asmlinkage void ret_from_fork(void);
  43 asmlinkage void ret_from_kernel_thread(void);
  44
  45 #include <asm/pgalloc.h>
  46
  47 void (*pm_power_off)(void);
  48 EXPORT_SYMBOL(pm_power_off);
  49
  50 static void core_sleep_idle(void)
  51 {
  52 #ifdef LED_DEBUG_SLEEP
  53         /* Show that we're sleeping... */
  54         __set_LEDS(0x55aa);
  55 #endif
  56         frv_cpu_core_sleep();
  57 #ifdef LED_DEBUG_SLEEP
  58         /* ... and that we woke up */
  59         __set_LEDS(0);
  60 #endif
  61         mb();
  62 }
  63
  64 void arch_cpu_idle(void)
  65 {
  66         if (!frv_dma_inprogress)
  67                 core_sleep_idle();
  68         else
  69                 local_irq_enable();
  70 }
  71
  72 void machine_restart(char * __unused)
  73 {
  74         unsigned long reset_addr;
  75 #ifdef CONFIG_GDBSTUB
  76         gdbstub_exit(0);
  77 #endif
  78
  79         if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
  80                 reset_addr = 0xfefff500;
  81         else
  82                 reset_addr = 0xfeff0500;
  83
  84         /* Software reset. */
  85         asm volatile("      dcef @(gr0,gr0),1 ! membar !"
  86                      "      sti     %1,@(%0,0) !"
  87                      "      nop ! nop ! nop ! nop ! nop ! "
  88                      "      nop ! nop ! nop ! nop ! nop ! "
  89                      "      nop ! nop ! nop ! nop ! nop ! "
  90                      "      nop ! nop ! nop ! nop ! nop ! "
  91                      : : "r" (reset_addr), "r" (1) );
  92
  93         for (;;)
  94                 ;
  95 }
  96
  97 void machine_halt(void)
  98 {
  99 #ifdef CONFIG_GDBSTUB
 100         gdbstub_exit(0);
 101 #endif
 102
 103         for (;;);
 104 }
 105
 106 void machine_power_off(void)
 107 {
 108 #ifdef CONFIG_GDBSTUB
 109         gdbstub_exit(0);
 110 #endif
 111
 112         for (;;);
 113 }
 114
 115 void flush_thread(void)
 116 {
 117         /* nothing */
 118 }
 119
 120 inline unsigned long user_stack(const struct pt_regs *regs)
 121 {
 122         while (regs->next_frame)
 123                 regs = regs->next_frame;
 124         return user_mode(regs) ? regs->sp : 0;
 125 }
 126
 127 /*
 128  * set up the kernel stack and exception frames for a new process
 129  */
 130 int copy_thread(unsigned long clone_flags,
 131                 unsigned long usp, unsigned long arg,
 132                 struct task_struct *p)
 133 {
 134         struct pt_regs *childregs;
 135
 136         childregs = (struct pt_regs *)
 137                 (task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
 138
 139         /* set up the userspace frame (the only place that the USP is stored) */
 140         *childregs = *current_pt_regs();
 141
 142         p->thread.frame  = childregs;
 143         p->thread.curr   = p;
 144         p->thread.sp     = (unsigned long) childregs;
 145         p->thread.fp     = 0;
 146         p->thread.lr     = 0;
 147         p->thread.frame0 = childregs;
 148
 149         if (unlikely(p->flags & PF_KTHREAD)) {
 150                 childregs->gr9 = usp; /* function */
 151                 childregs->gr8 = arg;
 152                 p->thread.pc = (unsigned long) ret_from_kernel_thread;
 153                 save_user_regs(p->thread.user);
 154                 return 0;
 155         }
 156         if (usp)
 157                 childregs->sp = usp;
 158         childregs->next_frame   = NULL;
 159
 160         p->thread.pc = (unsigned long) ret_from_fork;
 161
 162         /* the new TLS pointer is passed in as arg #5 to sys_clone() */
 163         if (clone_flags & CLONE_SETTLS)
 164                 childregs->gr29 = childregs->gr12;
 165
 166         save_user_regs(p->thread.user);
 167
 168         return 0;
 169 } /* end copy_thread() */
 170
 171 unsigned long get_wchan(struct task_struct *p)
 172 {
 173         struct pt_regs *regs0;
 174         unsigned long fp, pc;
 175         unsigned long stack_limit;
 176         int count = 0;
 177         if (!p || p == current || p->state == TASK_RUNNING)
 178                 return 0;
 179
 180         stack_limit = (unsigned long) (p + 1);
 181         fp = p->thread.fp;
 182         regs0 = p->thread.frame0;
 183
 184         do {
 185                 if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
 186                         return 0;
 187
 188                 pc = ((unsigned long *) fp)[2];
 189
 190                 /* FIXME: This depends on the order of these functions. */
 191                 if (!in_sched_functions(pc))
 192                         return pc;
 193
 194                 fp = *(unsigned long *) fp;
 195         } while (count++ < 16);
 196
 197         return 0;
 198 }
 199
 200 unsigned long thread_saved_pc(struct task_struct *tsk)
 201 {
 202         /* Check whether the thread is blocked in resume() */
 203         if (in_sched_functions(tsk->thread.pc))
 204                 return ((unsigned long *)tsk->thread.fp)[2];
 205         else
 206                 return tsk->thread.pc;
 207 }
 208
 209 int elf_check_arch(const struct elf32_hdr *hdr)
 210 {
 211         unsigned long hsr0 = __get_HSR(0);
 212         unsigned long psr = __get_PSR();
 213
 214         if (hdr->e_machine != EM_FRV)
 215                 return 0;
 216
 217         switch (hdr->e_flags & EF_FRV_GPR_MASK) {
 218         case EF_FRV_GPR64:
 219                 if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
 220                         return 0;
 221         case EF_FRV_GPR32:
 222         case 0:
 223                 break;
 224         default:
 225                 return 0;
 226         }
 227
 228         switch (hdr->e_flags & EF_FRV_FPR_MASK) {
 229         case EF_FRV_FPR64:
 230                 if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
 231                         return 0;
 232         case EF_FRV_FPR32:
 233         case EF_FRV_FPR_NONE:
 234         case 0:
 235                 break;
 236         default:
 237                 return 0;
 238         }
 239
 240         if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
 241                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 242                     PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 243                         return 0;
 244
 245         switch (hdr->e_flags & EF_FRV_CPU_MASK) {
 246         case EF_FRV_CPU_GENERIC:
 247                 break;
 248         case EF_FRV_CPU_FR300:
 249         case EF_FRV_CPU_SIMPLE:
 250         case EF_FRV_CPU_TOMCAT:
 251         default:
 252                 return 0;
 253         case EF_FRV_CPU_FR400:
 254                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
 255                     PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
 256                     PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
 257                     PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 258                         return 0;
 259                 break;
 260         case EF_FRV_CPU_FR450:
 261                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
 262                         return 0;
 263                 break;
 264         case EF_FRV_CPU_FR500:
 265                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
 266                         return 0;
 267                 break;
 268         case EF_FRV_CPU_FR550:
 269                 if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
 270                         return 0;
 271                 break;
 272         }
 273
 274         return 1;
 275 }
 276
 277 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
 278 {
 279         memcpy(fpregs,
 280                &current->thread.user->f,
 281                sizeof(current->thread.user->f));
 282         return 1;
 283 }