2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Copyright 2003 PathScale, Inc.
4 * Licensed under the GPL
7 #include "linux/stddef.h"
9 #include "linux/hardirq.h"
11 #include "linux/personality.h"
12 #include "linux/proc_fs.h"
13 #include "linux/ptrace.h"
14 #include "linux/random.h"
15 #include "linux/sched.h"
16 #include "linux/threads.h"
17 #include "asm/pgtable.h"
18 #include "asm/uaccess.h"
19 #include "as-layout.h"
20 #include "kern_util.h"
26 * This is a per-cpu array. A processor only modifies its entry and it only
27 * cares about its entry, so it's OK if another processor is modifying its
30 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
32 static inline int external_pid(struct task_struct *task)
34 /* FIXME: Need to look up userspace_pid by cpu */
35 return userspace_pid[0];
38 int pid_to_processor_id(int pid)
42 for(i = 0; i < ncpus; i++) {
43 if (cpu_tasks[i].pid == pid)
49 void free_stack(unsigned long stack, int order)
51 free_pages(stack, order);
54 unsigned long alloc_stack(int order, int atomic)
57 gfp_t flags = GFP_KERNEL;
61 page = __get_free_pages(flags, order);
68 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
72 current->thread.request.u.thread.proc = fn;
73 current->thread.request.u.thread.arg = arg;
74 pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
75 ¤t->thread.regs, 0, NULL, NULL);
79 static inline void set_current(struct task_struct *task)
81 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
82 { external_pid(task), task });
85 extern void arch_switch_to(struct task_struct *from, struct task_struct *to);
87 void *_switch_to(void *prev, void *next, void *last)
89 struct task_struct *from = prev;
90 struct task_struct *to= next;
92 to->thread.prev_sched = from;
96 current->thread.saved_task = NULL;
98 /* XXX need to check runqueues[cpu].idle */
99 if (current->pid == 0)
102 switch_threads(&from->thread.switch_buf,
103 &to->thread.switch_buf);
105 arch_switch_to(current->thread.prev_sched, current);
107 if (current->pid == 0)
110 if (current->thread.saved_task)
111 show_regs(&(current->thread.regs));
112 next= current->thread.saved_task;
114 } while(current->thread.saved_task);
116 return current->thread.prev_sched;
120 void interrupt_end(void)
124 if (test_tsk_thread_flag(current, TIF_SIGPENDING))
128 void exit_thread(void)
132 void *get_current(void)
137 extern void schedule_tail(struct task_struct *prev);
140 * This is called magically, by its address being stuffed in a jmp_buf
141 * and being longjmp-d to.
143 void new_thread_handler(void)
145 int (*fn)(void *), n;
148 if (current->thread.prev_sched != NULL)
149 schedule_tail(current->thread.prev_sched);
150 current->thread.prev_sched = NULL;
152 fn = current->thread.request.u.thread.proc;
153 arg = current->thread.request.u.thread.arg;
156 * The return value is 1 if the kernel thread execs a process,
159 n = run_kernel_thread(fn, arg, ¤t->thread.exec_buf);
161 /* Handle any immediate reschedules or signals */
163 userspace(¤t->thread.regs.regs);
168 /* Called magically, see new_thread_handler above */
169 void fork_handler(void)
172 if (current->thread.prev_sched == NULL)
175 schedule_tail(current->thread.prev_sched);
178 * XXX: if interrupt_end() calls schedule, this call to
179 * arch_switch_to isn't needed. We could want to apply this to
180 * improve performance. -bb
182 arch_switch_to(current->thread.prev_sched, current);
184 current->thread.prev_sched = NULL;
186 /* Handle any immediate reschedules or signals */
189 userspace(¤t->thread.regs.regs);
192 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
193 unsigned long stack_top, struct task_struct * p,
194 struct pt_regs *regs)
196 void (*handler)(void);
199 p->thread = (struct thread_struct) INIT_THREAD;
201 if (current->thread.forking) {
202 memcpy(&p->thread.regs.regs, ®s->regs,
203 sizeof(p->thread.regs.regs));
204 REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.gp, 0);
206 REGS_SP(p->thread.regs.regs.gp) = sp;
208 handler = fork_handler;
210 arch_copy_thread(¤t->thread.arch, &p->thread.arch);
213 init_thread_registers(&p->thread.regs.regs);
214 p->thread.request.u.thread = current->thread.request.u.thread;
215 handler = new_thread_handler;
218 new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
220 if (current->thread.forking) {
221 clear_flushed_tls(p);
224 * Set a new TLS for the child thread?
226 if (clone_flags & CLONE_SETTLS)
227 ret = arch_copy_tls(p);
233 void initial_thread_cb(void (*proc)(void *), void *arg)
235 int save_kmalloc_ok = kmalloc_ok;
238 initial_thread_cb_skas(proc, arg);
239 kmalloc_ok = save_kmalloc_ok;
242 void default_idle(void)
245 /* endless idle loop with no priority at all */
248 * although we are an idle CPU, we do not want to
249 * get into the scheduler unnecessarily.
260 cpu_tasks[current_thread->cpu].pid = os_getpid();
264 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
273 if (task->mm == NULL)
274 return ERR_PTR(-EINVAL);
275 pgd = pgd_offset(task->mm, addr);
276 if (!pgd_present(*pgd))
277 return ERR_PTR(-EINVAL);
279 pud = pud_offset(pgd, addr);
280 if (!pud_present(*pud))
281 return ERR_PTR(-EINVAL);
283 pmd = pmd_offset(pud, addr);
284 if (!pmd_present(*pmd))
285 return ERR_PTR(-EINVAL);
287 pte = pte_offset_kernel(pmd, addr);
289 if (!pte_present(ptent))
290 return ERR_PTR(-EINVAL);
294 return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
297 char *current_cmd(void)
299 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
302 void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
303 return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
307 void dump_thread(struct pt_regs *regs, struct user *u)
311 int __cant_sleep(void) {
312 return in_atomic() || irqs_disabled() || in_interrupt();
313 /* Is in_interrupt() really needed? */
316 int user_context(unsigned long sp)
320 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
321 return stack != (unsigned long) current_thread;
324 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
326 void do_uml_exitcalls(void)
330 call = &__uml_exitcall_end;
331 while (--call >= &__uml_exitcall_begin)
335 char *uml_strdup(char *string)
337 return kstrdup(string, GFP_KERNEL);
340 int copy_to_user_proc(void __user *to, void *from, int size)
342 return copy_to_user(to, from, size);
345 int copy_from_user_proc(void *to, void __user *from, int size)
347 return copy_from_user(to, from, size);
350 int clear_user_proc(void __user *buf, int size)
352 return clear_user(buf, size);
355 int strlen_user_proc(char __user *str)
357 return strlen_user(str);
360 int smp_sigio_handler(void)
363 int cpu = current_thread->cpu;
373 return current_thread->cpu;
376 static atomic_t using_sysemu = ATOMIC_INIT(0);
377 int sysemu_supported;
379 void set_using_sysemu(int value)
381 if (value > sysemu_supported)
383 atomic_set(&using_sysemu, value);
386 int get_using_sysemu(void)
388 return atomic_read(&using_sysemu);
391 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
393 if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size)
400 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
404 if (copy_from_user(tmp, buf, 1))
407 if (tmp[0] >= '0' && tmp[0] <= '2')
408 set_using_sysemu(tmp[0] - '0');
409 /* We use the first char, but pretend to write everything */
413 int __init make_proc_sysemu(void)
415 struct proc_dir_entry *ent;
416 if (!sysemu_supported)
419 ent = create_proc_entry("sysemu", 0600, &proc_root);
423 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
427 ent->read_proc = proc_read_sysemu;
428 ent->write_proc = proc_write_sysemu;
433 late_initcall(make_proc_sysemu);
435 int singlestepping(void * t)
437 struct task_struct *task = t ? t : current;
439 if ( ! (task->ptrace & PT_DTRACE) )
442 if (task->thread.singlestep_syscall)
449 * Only x86 and x86_64 have an arch_align_stack().
450 * All other arches have "#define arch_align_stack(x) (x)"
451 * in their asm/system.h
452 * As this is included in UML from asm-um/system-generic.h,
453 * we can use it to behave as the subarch does.
455 #ifndef arch_align_stack
456 unsigned long arch_align_stack(unsigned long sp)
458 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
459 sp -= get_random_int() % 8192;