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#include "um_malloc.h"
50
51/* This is a per-cpu array.  A processor only modifies its entry and it only
52 * cares about its entry, so it's OK if another processor is modifying its
53 * entry.
54 */
55struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
56
57static inline int external_pid(struct task_struct *task)
58{
59	return CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task);
60}
61
62int pid_to_processor_id(int pid)
63{
64	int i;
65
66	for(i = 0; i < ncpus; i++){
67		if(cpu_tasks[i].pid == pid)
68			return i;
69	}
70	return -1;
71}
72
73void free_stack(unsigned long stack, int order)
74{
75	free_pages(stack, order);
76}
77
78unsigned long alloc_stack(int order, int atomic)
79{
80	unsigned long page;
81	gfp_t flags = GFP_KERNEL;
82
83	if (atomic)
84		flags = GFP_ATOMIC;
85	page = __get_free_pages(flags, order);
86	if(page == 0)
87		return 0;
88	stack_protections(page);
89	return page;
90}
91
92int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
93{
94	int pid;
95
96	current->thread.request.u.thread.proc = fn;
97	current->thread.request.u.thread.arg = arg;
98	pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
99		      &current->thread.regs, 0, NULL, NULL);
100	return pid;
101}
102
103static inline void set_current(struct task_struct *task)
104{
105	cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
106		{ external_pid(task), task });
107}
108
109void *_switch_to(void *prev, void *next, void *last)
110{
111	struct task_struct *from = prev;
112	struct task_struct *to= next;
113
114	to->thread.prev_sched = from;
115	set_current(to);
116
117	do {
118		current->thread.saved_task = NULL ;
119		CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
120		if(current->thread.saved_task)
121			show_regs(&(current->thread.regs));
122		next= current->thread.saved_task;
123		prev= current;
124	} while(current->thread.saved_task);
125
126	return current->thread.prev_sched;
127
128}
129
130void interrupt_end(void)
131{
132	if(need_resched())
133		schedule();
134	if(test_tsk_thread_flag(current, TIF_SIGPENDING))
135		do_signal();
136}
137
138void release_thread(struct task_struct *task)
139{
140	CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
141}
142
143void exit_thread(void)
144{
145	unprotect_stack((unsigned long) current_thread);
146}
147
148void *get_current(void)
149{
150	return current;
151}
152
153int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
154		unsigned long stack_top, struct task_struct * p,
155		struct pt_regs *regs)
156{
157	int ret;
158
159	p->thread = (struct thread_struct) INIT_THREAD;
160	ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
161				clone_flags, sp, stack_top, p, regs);
162
163	if (ret || !current->thread.forking)
164		goto out;
165
166	clear_flushed_tls(p);
167
168	/*
169	 * Set a new TLS for the child thread?
170	 */
171	if (clone_flags & CLONE_SETTLS)
172		ret = arch_copy_tls(p);
173
174out:
175	return ret;
176}
177
178void initial_thread_cb(void (*proc)(void *), void *arg)
179{
180	int save_kmalloc_ok = kmalloc_ok;
181
182	kmalloc_ok = 0;
183	CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
184			 arg);
185	kmalloc_ok = save_kmalloc_ok;
186}
187
188#ifdef CONFIG_MODE_TT
189unsigned long stack_sp(unsigned long page)
190{
191	return page + PAGE_SIZE - sizeof(void *);
192}
193#endif
194
195void default_idle(void)
196{
197	CHOOSE_MODE(uml_idle_timer(), (void) 0);
198
199	while(1){
200		/* endless idle loop with no priority at all */
201
202		/*
203		 * although we are an idle CPU, we do not want to
204		 * get into the scheduler unnecessarily.
205		 */
206		if(need_resched())
207			schedule();
208
209		idle_sleep(10);
210	}
211}
212
213void cpu_idle(void)
214{
215	CHOOSE_MODE(init_idle_tt(), init_idle_skas());
216}
217
218void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
219		      pte_t *pte_out)
220{
221	pgd_t *pgd;
222	pud_t *pud;
223	pmd_t *pmd;
224	pte_t *pte;
225	pte_t ptent;
226
227	if(task->mm == NULL)
228		return ERR_PTR(-EINVAL);
229	pgd = pgd_offset(task->mm, addr);
230	if(!pgd_present(*pgd))
231		return ERR_PTR(-EINVAL);
232
233	pud = pud_offset(pgd, addr);
234	if(!pud_present(*pud))
235		return ERR_PTR(-EINVAL);
236
237	pmd = pmd_offset(pud, addr);
238	if(!pmd_present(*pmd))
239		return ERR_PTR(-EINVAL);
240
241	pte = pte_offset_kernel(pmd, addr);
242	ptent = *pte;
243	if(!pte_present(ptent))
244		return ERR_PTR(-EINVAL);
245
246	if(pte_out != NULL)
247		*pte_out = ptent;
248	return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
249}
250
251char *current_cmd(void)
252{
253#if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
254	return "(Unknown)";
255#else
256	void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
257	return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
258#endif
259}
260
261void dump_thread(struct pt_regs *regs, struct user *u)
262{
263}
264
265void *um_kmalloc(int size)
266{
267	return kmalloc(size, GFP_KERNEL);
268}
269
270void *um_kmalloc_atomic(int size)
271{
272	return kmalloc(size, GFP_ATOMIC);
273}
274
275void *um_vmalloc(int size)
276{
277	return vmalloc(size);
278}
279
280int __cant_sleep(void) {
281	return in_atomic() || irqs_disabled() || in_interrupt();
282	/* Is in_interrupt() really needed? */
283}
284
285int user_context(unsigned long sp)
286{
287	unsigned long stack;
288
289	stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
290	return stack != (unsigned long) current_thread;
291}
292
293extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
294
295void do_uml_exitcalls(void)
296{
297	exitcall_t *call;
298
299	call = &__uml_exitcall_end;
300	while (--call >= &__uml_exitcall_begin)
301		(*call)();
302}
303
304char *uml_strdup(char *string)
305{
306	return kstrdup(string, GFP_KERNEL);
307}
308
309int copy_to_user_proc(void __user *to, void *from, int size)
310{
311	return copy_to_user(to, from, size);
312}
313
314int copy_from_user_proc(void *to, void __user *from, int size)
315{
316	return copy_from_user(to, from, size);
317}
318
319int clear_user_proc(void __user *buf, int size)
320{
321	return clear_user(buf, size);
322}
323
324int strlen_user_proc(char __user *str)
325{
326	return strlen_user(str);
327}
328
329int smp_sigio_handler(void)
330{
331#ifdef CONFIG_SMP
332	int cpu = current_thread->cpu;
333	IPI_handler(cpu);
334	if(cpu != 0)
335		return 1;
336#endif
337	return 0;
338}
339
340int cpu(void)
341{
342	return current_thread->cpu;
343}
344
345static atomic_t using_sysemu = ATOMIC_INIT(0);
346int sysemu_supported;
347
348void set_using_sysemu(int value)
349{
350	if (value > sysemu_supported)
351		return;
352	atomic_set(&using_sysemu, value);
353}
354
355int get_using_sysemu(void)
356{
357	return atomic_read(&using_sysemu);
358}
359
360static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
361{
362	if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
363		*eof = 1;
364
365	return strlen(buf);
366}
367
368static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
369{
370	char tmp[2];
371
372	if (copy_from_user(tmp, buf, 1))
373		return -EFAULT;
374
375	if (tmp[0] >= '0' && tmp[0] <= '2')
376		set_using_sysemu(tmp[0] - '0');
377	return count; /*We use the first char, but pretend to write everything*/
378}
379
380int __init make_proc_sysemu(void)
381{
382	struct proc_dir_entry *ent;
383	if (!sysemu_supported)
384		return 0;
385
386	ent = create_proc_entry("sysemu", 0600, &proc_root);
387
388	if (ent == NULL)
389	{
390		printk(KERN_WARNING "Failed to register /proc/sysemu\n");
391		return 0;
392	}
393
394	ent->read_proc  = proc_read_sysemu;
395	ent->write_proc = proc_write_sysemu;
396
397	return 0;
398}
399
400late_initcall(make_proc_sysemu);
401
402int singlestepping(void * t)
403{
404	struct task_struct *task = t ? t : current;
405
406	if ( ! (task->ptrace & PT_DTRACE) )
407		return(0);
408
409	if (task->thread.singlestep_syscall)
410		return(1);
411
412	return 2;
413}
414
415/*
416 * Only x86 and x86_64 have an arch_align_stack().
417 * All other arches have "#define arch_align_stack(x) (x)"
418 * in their asm/system.h
419 * As this is included in UML from asm-um/system-generic.h,
420 * we can use it to behave as the subarch does.
421 */
422#ifndef arch_align_stack
423unsigned long arch_align_stack(unsigned long sp)
424{
425	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
426		sp -= get_random_int() % 8192;
427	return sp & ~0xf;
428}
429#endif
430