1 /* 2 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) 3 * Copyright 2003 PathScale, Inc. 4 * Licensed under the GPL 5 */ 6 7 #include "linux/kernel.h" 8 #include "linux/sched.h" 9 #include "linux/interrupt.h" 10 #include "linux/string.h" 11 #include "linux/mm.h" 12 #include "linux/slab.h" 13 #include "linux/utsname.h" 14 #include "linux/fs.h" 15 #include "linux/utime.h" 16 #include "linux/smp_lock.h" 17 #include "linux/module.h" 18 #include "linux/init.h" 19 #include "linux/capability.h" 20 #include "linux/vmalloc.h" 21 #include "linux/spinlock.h" 22 #include "linux/proc_fs.h" 23 #include "linux/ptrace.h" 24 #include "linux/random.h" 25 #include "linux/personality.h" 26 #include "asm/unistd.h" 27 #include "asm/mman.h" 28 #include "asm/segment.h" 29 #include "asm/stat.h" 30 #include "asm/pgtable.h" 31 #include "asm/processor.h" 32 #include "asm/tlbflush.h" 33 #include "asm/uaccess.h" 34 #include "asm/user.h" 35 #include "kern_util.h" 36 #include "as-layout.h" 37 #include "kern.h" 38 #include "signal_kern.h" 39 #include "init.h" 40 #include "irq_user.h" 41 #include "mem_user.h" 42 #include "tlb.h" 43 #include "frame_kern.h" 44 #include "sigcontext.h" 45 #include "os.h" 46 #include "mode.h" 47 #include "mode_kern.h" 48 #include "choose-mode.h" 49 50 /* This is a per-cpu array. A processor only modifies its entry and it only 51 * cares about its entry, so it's OK if another processor is modifying its 52 * entry. 53 */ 54 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; 55 56 static inline int external_pid(struct task_struct *task) 57 { 58 return CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task); 59 } 60 61 int pid_to_processor_id(int pid) 62 { 63 int i; 64 65 for(i = 0; i < ncpus; i++){ 66 if(cpu_tasks[i].pid == pid) 67 return i; 68 } 69 return -1; 70 } 71 72 void free_stack(unsigned long stack, int order) 73 { 74 free_pages(stack, order); 75 } 76 77 unsigned long alloc_stack(int order, int atomic) 78 { 79 unsigned long page; 80 gfp_t flags = GFP_KERNEL; 81 82 if (atomic) 83 flags = GFP_ATOMIC; 84 page = __get_free_pages(flags, order); 85 if(page == 0) 86 return 0; 87 stack_protections(page); 88 return page; 89 } 90 91 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 92 { 93 int pid; 94 95 current->thread.request.u.thread.proc = fn; 96 current->thread.request.u.thread.arg = arg; 97 pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, 98 ¤t->thread.regs, 0, NULL, NULL); 99 return pid; 100 } 101 102 static inline void set_current(struct task_struct *task) 103 { 104 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task) 105 { external_pid(task), task }); 106 } 107 108 void *_switch_to(void *prev, void *next, void *last) 109 { 110 struct task_struct *from = prev; 111 struct task_struct *to= next; 112 113 to->thread.prev_sched = from; 114 set_current(to); 115 116 do { 117 current->thread.saved_task = NULL ; 118 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next); 119 if(current->thread.saved_task) 120 show_regs(&(current->thread.regs)); 121 next= current->thread.saved_task; 122 prev= current; 123 } while(current->thread.saved_task); 124 125 return current->thread.prev_sched; 126 127 } 128 129 void interrupt_end(void) 130 { 131 if(need_resched()) 132 schedule(); 133 if(test_tsk_thread_flag(current, TIF_SIGPENDING)) 134 do_signal(); 135 } 136 137 void release_thread(struct task_struct *task) 138 { 139 CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task)); 140 } 141 142 void exit_thread(void) 143 { 144 unprotect_stack((unsigned long) current_thread); 145 } 146 147 void *get_current(void) 148 { 149 return current; 150 } 151 152 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 153 unsigned long stack_top, struct task_struct * p, 154 struct pt_regs *regs) 155 { 156 int ret; 157 158 p->thread = (struct thread_struct) INIT_THREAD; 159 ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr, 160 clone_flags, sp, stack_top, p, regs); 161 162 if (ret || !current->thread.forking) 163 goto out; 164 165 clear_flushed_tls(p); 166 167 /* 168 * Set a new TLS for the child thread? 169 */ 170 if (clone_flags & CLONE_SETTLS) 171 ret = arch_copy_tls(p); 172 173 out: 174 return ret; 175 } 176 177 void initial_thread_cb(void (*proc)(void *), void *arg) 178 { 179 int save_kmalloc_ok = kmalloc_ok; 180 181 kmalloc_ok = 0; 182 CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc, 183 arg); 184 kmalloc_ok = save_kmalloc_ok; 185 } 186 187 #ifdef CONFIG_MODE_TT 188 unsigned long stack_sp(unsigned long page) 189 { 190 return page + PAGE_SIZE - sizeof(void *); 191 } 192 #endif 193 194 void default_idle(void) 195 { 196 CHOOSE_MODE(uml_idle_timer(), (void) 0); 197 198 while(1){ 199 /* endless idle loop with no priority at all */ 200 201 /* 202 * although we are an idle CPU, we do not want to 203 * get into the scheduler unnecessarily. 204 */ 205 if(need_resched()) 206 schedule(); 207 208 idle_sleep(10); 209 } 210 } 211 212 void cpu_idle(void) 213 { 214 CHOOSE_MODE(init_idle_tt(), init_idle_skas()); 215 } 216 217 void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 218 pte_t *pte_out) 219 { 220 pgd_t *pgd; 221 pud_t *pud; 222 pmd_t *pmd; 223 pte_t *pte; 224 pte_t ptent; 225 226 if(task->mm == NULL) 227 return ERR_PTR(-EINVAL); 228 pgd = pgd_offset(task->mm, addr); 229 if(!pgd_present(*pgd)) 230 return ERR_PTR(-EINVAL); 231 232 pud = pud_offset(pgd, addr); 233 if(!pud_present(*pud)) 234 return ERR_PTR(-EINVAL); 235 236 pmd = pmd_offset(pud, addr); 237 if(!pmd_present(*pmd)) 238 return ERR_PTR(-EINVAL); 239 240 pte = pte_offset_kernel(pmd, addr); 241 ptent = *pte; 242 if(!pte_present(ptent)) 243 return ERR_PTR(-EINVAL); 244 245 if(pte_out != NULL) 246 *pte_out = ptent; 247 return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK); 248 } 249 250 char *current_cmd(void) 251 { 252 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM) 253 return "(Unknown)"; 254 #else 255 void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL); 256 return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr); 257 #endif 258 } 259 260 void dump_thread(struct pt_regs *regs, struct user *u) 261 { 262 } 263 264 int __cant_sleep(void) { 265 return in_atomic() || irqs_disabled() || in_interrupt(); 266 /* Is in_interrupt() really needed? */ 267 } 268 269 int user_context(unsigned long sp) 270 { 271 unsigned long stack; 272 273 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); 274 return stack != (unsigned long) current_thread; 275 } 276 277 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; 278 279 void do_uml_exitcalls(void) 280 { 281 exitcall_t *call; 282 283 call = &__uml_exitcall_end; 284 while (--call >= &__uml_exitcall_begin) 285 (*call)(); 286 } 287 288 char *uml_strdup(char *string) 289 { 290 return kstrdup(string, GFP_KERNEL); 291 } 292 293 int copy_to_user_proc(void __user *to, void *from, int size) 294 { 295 return copy_to_user(to, from, size); 296 } 297 298 int copy_from_user_proc(void *to, void __user *from, int size) 299 { 300 return copy_from_user(to, from, size); 301 } 302 303 int clear_user_proc(void __user *buf, int size) 304 { 305 return clear_user(buf, size); 306 } 307 308 int strlen_user_proc(char __user *str) 309 { 310 return strlen_user(str); 311 } 312 313 int smp_sigio_handler(void) 314 { 315 #ifdef CONFIG_SMP 316 int cpu = current_thread->cpu; 317 IPI_handler(cpu); 318 if(cpu != 0) 319 return 1; 320 #endif 321 return 0; 322 } 323 324 int cpu(void) 325 { 326 return current_thread->cpu; 327 } 328 329 static atomic_t using_sysemu = ATOMIC_INIT(0); 330 int sysemu_supported; 331 332 void set_using_sysemu(int value) 333 { 334 if (value > sysemu_supported) 335 return; 336 atomic_set(&using_sysemu, value); 337 } 338 339 int get_using_sysemu(void) 340 { 341 return atomic_read(&using_sysemu); 342 } 343 344 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data) 345 { 346 if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/ 347 *eof = 1; 348 349 return strlen(buf); 350 } 351 352 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data) 353 { 354 char tmp[2]; 355 356 if (copy_from_user(tmp, buf, 1)) 357 return -EFAULT; 358 359 if (tmp[0] >= '0' && tmp[0] <= '2') 360 set_using_sysemu(tmp[0] - '0'); 361 return count; /*We use the first char, but pretend to write everything*/ 362 } 363 364 int __init make_proc_sysemu(void) 365 { 366 struct proc_dir_entry *ent; 367 if (!sysemu_supported) 368 return 0; 369 370 ent = create_proc_entry("sysemu", 0600, &proc_root); 371 372 if (ent == NULL) 373 { 374 printk(KERN_WARNING "Failed to register /proc/sysemu\n"); 375 return 0; 376 } 377 378 ent->read_proc = proc_read_sysemu; 379 ent->write_proc = proc_write_sysemu; 380 381 return 0; 382 } 383 384 late_initcall(make_proc_sysemu); 385 386 int singlestepping(void * t) 387 { 388 struct task_struct *task = t ? t : current; 389 390 if ( ! (task->ptrace & PT_DTRACE) ) 391 return(0); 392 393 if (task->thread.singlestep_syscall) 394 return(1); 395 396 return 2; 397 } 398 399 /* 400 * Only x86 and x86_64 have an arch_align_stack(). 401 * All other arches have "#define arch_align_stack(x) (x)" 402 * in their asm/system.h 403 * As this is included in UML from asm-um/system-generic.h, 404 * we can use it to behave as the subarch does. 405 */ 406 #ifndef arch_align_stack 407 unsigned long arch_align_stack(unsigned long sp) 408 { 409 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 410 sp -= get_random_int() % 8192; 411 return sp & ~0xf; 412 } 413 #endif 414