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/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#include <linux/pagemap.h> 29 30#include <asm/asm-offsets.h> 31#include <asm/uaccess.h> 32#include <asm/system.h> 33#include <asm/setup.h> 34#include <asm/pgtable.h> 35#include <asm/tlb.h> 36#include <asm/gdb-stub.h> 37#include <asm/mb-regs.h> 38 39#include "local.h" 40 41asmlinkage void ret_from_fork(void); 42 43#include <asm/pgalloc.h> 44 45void (*pm_power_off)(void); 46EXPORT_SYMBOL(pm_power_off); 47 48struct task_struct *alloc_task_struct(void) 49{ 50 struct task_struct *p = kmalloc(THREAD_SIZE, GFP_KERNEL); 51 if (p) 52 atomic_set((atomic_t *)(p+1), 1); 53 return p; 54} 55 56void free_task_struct(struct task_struct *p) 57{ 58 if (atomic_dec_and_test((atomic_t *)(p+1))) 59 kfree(p); 60} 61 62static 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 76void (*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 */ 84void 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 101void 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 126void machine_halt(void) 127{ 128#ifdef CONFIG_GDBSTUB 129 gdbstub_exit(0); 130#endif 131 132 for (;;); 133} 134 135void machine_power_off(void) 136{ 137#ifdef CONFIG_GDBSTUB 138 gdbstub_exit(0); 139#endif 140 141 for (;;); 142} 143 144void flush_thread(void) 145{ 146 set_fs(USER_DS); 147} 148 149inline 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 156asmlinkage 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 166asmlinkage 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 */ 177asmlinkage 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 */ 191void 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 */ 200int 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 */ 250asmlinkage 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 266unsigned 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 if (!in_sched_functions(pc)) 286 return pc; 287 288 fp = *(unsigned long *) fp; 289 } while (count++ < 16); 290 291 return 0; 292} 293 294unsigned long thread_saved_pc(struct task_struct *tsk) 295{ 296 /* Check whether the thread is blocked in resume() */ 297 if (in_sched_functions(tsk->thread.pc)) 298 return ((unsigned long *)tsk->thread.fp)[2]; 299 else 300 return tsk->thread.pc; 301} 302 303int elf_check_arch(const struct elf32_hdr *hdr) 304{ 305 unsigned long hsr0 = __get_HSR(0); 306 unsigned long psr = __get_PSR(); 307 308 if (hdr->e_machine != EM_FRV) 309 return 0; 310 311 switch (hdr->e_flags & EF_FRV_GPR_MASK) { 312 case EF_FRV_GPR64: 313 if ((hsr0 & HSR0_GRN) == HSR0_GRN_32) 314 return 0; 315 case EF_FRV_GPR32: 316 case 0: 317 break; 318 default: 319 return 0; 320 } 321 322 switch (hdr->e_flags & EF_FRV_FPR_MASK) { 323 case EF_FRV_FPR64: 324 if ((hsr0 & HSR0_FRN) == HSR0_FRN_32) 325 return 0; 326 case EF_FRV_FPR32: 327 case EF_FRV_FPR_NONE: 328 case 0: 329 break; 330 default: 331 return 0; 332 } 333 334 if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD) 335 if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 && 336 PSR_IMPLE(psr) != PSR_IMPLE_FR451) 337 return 0; 338 339 switch (hdr->e_flags & EF_FRV_CPU_MASK) { 340 case EF_FRV_CPU_GENERIC: 341 break; 342 case EF_FRV_CPU_FR300: 343 case EF_FRV_CPU_SIMPLE: 344 case EF_FRV_CPU_TOMCAT: 345 default: 346 return 0; 347 case EF_FRV_CPU_FR400: 348 if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 && 349 PSR_IMPLE(psr) != PSR_IMPLE_FR405 && 350 PSR_IMPLE(psr) != PSR_IMPLE_FR451 && 351 PSR_IMPLE(psr) != PSR_IMPLE_FR551) 352 return 0; 353 break; 354 case EF_FRV_CPU_FR450: 355 if (PSR_IMPLE(psr) != PSR_IMPLE_FR451) 356 return 0; 357 break; 358 case EF_FRV_CPU_FR500: 359 if (PSR_IMPLE(psr) != PSR_IMPLE_FR501) 360 return 0; 361 break; 362 case EF_FRV_CPU_FR550: 363 if (PSR_IMPLE(psr) != PSR_IMPLE_FR551) 364 return 0; 365 break; 366 } 367 368 return 1; 369} 370 371int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs) 372{ 373 memcpy(fpregs, 374 ¤t->thread.user->f, 375 sizeof(current->thread.user->f)); 376 return 1; 377} 378