1/* 2 * linux/arch/arm26/kernel/process.c 3 * 4 * Copyright (C) 2003 Ian Molton - adapted for ARM26 5 * Copyright (C) 1996-2000 Russell King - Converted to ARM. 6 * Origional Copyright (C) 1995 Linus Torvalds 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12#include <stdarg.h> 13 14#include <linux/module.h> 15#include <linux/sched.h> 16#include <linux/kernel.h> 17#include <linux/mm.h> 18#include <linux/stddef.h> 19#include <linux/unistd.h> 20#include <linux/ptrace.h> 21#include <linux/slab.h> 22#include <linux/user.h> 23#include <linux/a.out.h> 24#include <linux/delay.h> 25#include <linux/reboot.h> 26#include <linux/interrupt.h> 27#include <linux/init.h> 28 29#include <asm/system.h> 30#include <asm/io.h> 31#include <asm/leds.h> 32#include <asm/processor.h> 33#include <asm/uaccess.h> 34 35extern const char *processor_modes[]; 36extern void setup_mm_for_reboot(char mode); 37 38static volatile int hlt_counter; 39 40void disable_hlt(void) 41{ 42 hlt_counter++; 43} 44 45EXPORT_SYMBOL(disable_hlt); 46 47void enable_hlt(void) 48{ 49 hlt_counter--; 50} 51 52EXPORT_SYMBOL(enable_hlt); 53 54static int __init nohlt_setup(char *__unused) 55{ 56 hlt_counter = 1; 57 return 1; 58} 59 60static int __init hlt_setup(char *__unused) 61{ 62 hlt_counter = 0; 63 return 1; 64} 65 66__setup("nohlt", nohlt_setup); 67__setup("hlt", hlt_setup); 68 69/* 70 * This is our default idle handler. We need to disable 71 * interrupts here to ensure we don't miss a wakeup call. 72 */ 73void cpu_idle(void) 74{ 75 /* endless idle loop with no priority at all */ 76 while (1) { 77 while (!need_resched()) 78 cpu_relax(); 79 preempt_enable_no_resched(); 80 schedule(); 81 preempt_disable(); 82 } 83} 84 85static char reboot_mode = 'h'; 86 87int __init reboot_setup(char *str) 88{ 89 reboot_mode = str[0]; 90 return 1; 91} 92 93__setup("reboot=", reboot_setup); 94 95/* ARM26 cant do these but we still need to define them. */ 96void machine_halt(void) 97{ 98} 99void machine_power_off(void) 100{ 101} 102 103void machine_restart(char * __unused) 104{ 105 /* 106 * Clean and disable cache, and turn off interrupts 107 */ 108 cpu_proc_fin(); 109 110 /* 111 * Tell the mm system that we are going to reboot - 112 * we may need it to insert some 1:1 mappings so that 113 * soft boot works. 114 */ 115 setup_mm_for_reboot(reboot_mode); 116 117 /* 118 * copy branch instruction to reset location and call it 119 */ 120 121 *(unsigned long *)0 = *(unsigned long *)0x03800000; 122 ((void(*)(void))0)(); 123 124 /* 125 * Whoops - the architecture was unable to reboot. 126 * Tell the user! Should never happen... 127 */ 128 mdelay(1000); 129 printk("Reboot failed -- System halted\n"); 130 while (1); 131} 132 133void show_regs(struct pt_regs * regs) 134{ 135 unsigned long flags; 136 137 flags = condition_codes(regs); 138 139 printk("pc : [<%08lx>] lr : [<%08lx>] %s\n" 140 "sp : %08lx ip : %08lx fp : %08lx\n", 141 instruction_pointer(regs), 142 regs->ARM_lr, print_tainted(), regs->ARM_sp, 143 regs->ARM_ip, regs->ARM_fp); 144 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 145 regs->ARM_r10, regs->ARM_r9, 146 regs->ARM_r8); 147 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 148 regs->ARM_r7, regs->ARM_r6, 149 regs->ARM_r5, regs->ARM_r4); 150 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 151 regs->ARM_r3, regs->ARM_r2, 152 regs->ARM_r1, regs->ARM_r0); 153 printk("Flags: %c%c%c%c", 154 flags & PSR_N_BIT ? 'N' : 'n', 155 flags & PSR_Z_BIT ? 'Z' : 'z', 156 flags & PSR_C_BIT ? 'C' : 'c', 157 flags & PSR_V_BIT ? 'V' : 'v'); 158 printk(" IRQs o%s FIQs o%s Mode %s Segment %s\n", 159 interrupts_enabled(regs) ? "n" : "ff", 160 fast_interrupts_enabled(regs) ? "n" : "ff", 161 processor_modes[processor_mode(regs)], 162 get_fs() == get_ds() ? "kernel" : "user"); 163} 164 165void show_fpregs(struct user_fp *regs) 166{ 167 int i; 168 169 for (i = 0; i < 8; i++) { 170 unsigned long *p; 171 char type; 172 173 p = (unsigned long *)(regs->fpregs + i); 174 175 switch (regs->ftype[i]) { 176 case 1: type = 'f'; break; 177 case 2: type = 'd'; break; 178 case 3: type = 'e'; break; 179 default: type = '?'; break; 180 } 181 if (regs->init_flag) 182 type = '?'; 183 184 printk(" f%d(%c): %08lx %08lx %08lx%c", 185 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 186 } 187 188 189 printk("FPSR: %08lx FPCR: %08lx\n", 190 (unsigned long)regs->fpsr, 191 (unsigned long)regs->fpcr); 192} 193 194/* 195 * Task structure and kernel stack allocation. 196 */ 197static unsigned long *thread_info_head; 198static unsigned int nr_thread_info; 199 200extern unsigned long get_page_8k(int priority); 201extern void free_page_8k(unsigned long page); 202 203#define EXTRA_TASK_STRUCT 0 204#define ll_alloc_task_struct() ((struct thread_info *)get_page_8k(GFP_KERNEL)) 205#define ll_free_task_struct(p) free_page_8k((unsigned long)(p)) 206 207struct thread_info *alloc_thread_info(struct task_struct *task) 208{ 209 struct thread_info *thread = NULL; 210 211 if (EXTRA_TASK_STRUCT) { 212 unsigned long *p = thread_info_head; 213 214 if (p) { 215 thread_info_head = (unsigned long *)p[0]; 216 nr_thread_info -= 1; 217 } 218 thread = (struct thread_info *)p; 219 } 220 221 if (!thread) 222 thread = ll_alloc_task_struct(); 223 224#ifdef CONFIG_MAGIC_SYSRQ 225 /* 226 * The stack must be cleared if you want SYSRQ-T to 227 * give sensible stack usage information 228 */ 229 if (thread) { 230 char *p = (char *)thread; 231 memzero(p+KERNEL_STACK_SIZE, KERNEL_STACK_SIZE); 232 } 233#endif 234 return thread; 235} 236 237void free_thread_info(struct thread_info *thread) 238{ 239 if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) { 240 unsigned long *p = (unsigned long *)thread; 241 p[0] = (unsigned long)thread_info_head; 242 thread_info_head = p; 243 nr_thread_info += 1; 244 } else 245 ll_free_task_struct(thread); 246} 247 248/* 249 * Free current thread data structures etc.. 250 */ 251void exit_thread(void) 252{ 253} 254 255void flush_thread(void) 256{ 257 struct thread_info *thread = current_thread_info(); 258 struct task_struct *tsk = current; 259 260 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 261 memset(&thread->fpstate, 0, sizeof(union fp_state)); 262 263 clear_used_math(); 264} 265 266void release_thread(struct task_struct *dead_task) 267{ 268} 269 270asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 271 272int 273copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 274 unsigned long unused, struct task_struct *p, struct pt_regs *regs) 275{ 276 struct thread_info *thread = task_thread_info(p); 277 struct pt_regs *childregs = task_pt_regs(p); 278 279 *childregs = *regs; 280 childregs->ARM_r0 = 0; 281 childregs->ARM_sp = stack_start; 282 283 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 284 thread->cpu_context.sp = (unsigned long)childregs; 285 thread->cpu_context.pc = (unsigned long)ret_from_fork | MODE_SVC26 | PSR_I_BIT; 286 287 return 0; 288} 289 290/* 291 * fill in the fpe structure for a core dump... 292 */ 293int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 294{ 295 struct thread_info *thread = current_thread_info(); 296 int used_math = !!used_math(); 297 298 if (used_math) 299 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 300 301 return used_math; 302} 303 304/* 305 * fill in the user structure for a core dump.. 306 */ 307void dump_thread(struct pt_regs * regs, struct user * dump) 308{ 309 struct task_struct *tsk = current; 310 311 dump->magic = CMAGIC; 312 dump->start_code = tsk->mm->start_code; 313 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); 314 315 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; 316 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; 317 dump->u_ssize = 0; 318 319 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; 320 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; 321 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn; 322 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn; 323 dump->u_debugreg[4] = tsk->thread.debug.nsaved; 324 325 if (dump->start_stack < 0x04000000) 326 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; 327 328 dump->regs = *regs; 329 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); 330} 331 332extern void kernel_thread_helper(void); 333 334asm( ".section .text\n" 335" .align\n" 336" .type kernel_thread_helper, #function\n" 337"kernel_thread_helper:\n" 338" mov r0, r1\n" 339" mov lr, r3\n" 340" mov pc, r2\n" 341" .size kernel_thread_helper, . - kernel_thread_helper\n" 342" .previous"); 343 344/* 345 * Create a kernel thread. 346 */ 347pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 348{ 349 struct pt_regs regs; 350 351 memset(®s, 0, sizeof(regs)); 352 353 regs.ARM_r1 = (unsigned long)arg; 354 regs.ARM_r2 = (unsigned long)fn; 355 regs.ARM_r3 = (unsigned long)do_exit; 356 regs.ARM_pc = (unsigned long)kernel_thread_helper | MODE_SVC26; 357 358 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 359} 360EXPORT_SYMBOL(kernel_thread); 361 362 363unsigned long get_wchan(struct task_struct *p) 364{ 365 unsigned long fp, lr; 366 unsigned long stack_page; 367 int count = 0; 368 if (!p || p == current || p->state == TASK_RUNNING) 369 return 0; 370 371 stack_page = 4096 + (unsigned long)p; 372 fp = thread_saved_fp(p); 373 do { 374 if (fp < stack_page || fp > 4092+stack_page) 375 return 0; 376 lr = pc_pointer (((unsigned long *)fp)[-1]); 377 if (!in_sched_functions(lr)) 378 return lr; 379 fp = *(unsigned long *) (fp - 12); 380 } while (count ++ < 16); 381 return 0; 382} 383