1/*
2 * arch/sh/kernel/process_64.c
3 *
4 * This file handles the architecture-dependent parts of process handling..
5 *
6 * Copyright (C) 2000, 2001  Paolo Alberelli
7 * Copyright (C) 2003 - 2007  Paul Mundt
8 * Copyright (C) 2003, 2004 Richard Curnow
9 *
10 * Started from SH3/4 version:
11 *   Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
12 *
13 *   In turn started from i386 version:
14 *     Copyright (C) 1995  Linus Torvalds
15 *
16 * This file is subject to the terms and conditions of the GNU General Public
17 * License.  See the file "COPYING" in the main directory of this archive
18 * for more details.
19 */
20#include <linux/mm.h>
21#include <linux/fs.h>
22#include <linux/ptrace.h>
23#include <linux/reboot.h>
24#include <linux/slab.h>
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/io.h>
28#include <asm/syscalls.h>
29#include <asm/uaccess.h>
30#include <asm/pgtable.h>
31#include <asm/mmu_context.h>
32#include <asm/fpu.h>
33#include <asm/switch_to.h>
34
35struct task_struct *last_task_used_math = NULL;
36struct pt_regs fake_swapper_regs = { 0, };
37
38void show_regs(struct pt_regs *regs)
39{
40	unsigned long long ah, al, bh, bl, ch, cl;
41
42	printk("\n");
43	show_regs_print_info(KERN_DEFAULT);
44
45	ah = (regs->pc) >> 32;
46	al = (regs->pc) & 0xffffffff;
47	bh = (regs->regs[18]) >> 32;
48	bl = (regs->regs[18]) & 0xffffffff;
49	ch = (regs->regs[15]) >> 32;
50	cl = (regs->regs[15]) & 0xffffffff;
51	printk("PC  : %08Lx%08Lx LINK: %08Lx%08Lx SP  : %08Lx%08Lx\n",
52	       ah, al, bh, bl, ch, cl);
53
54	ah = (regs->sr) >> 32;
55	al = (regs->sr) & 0xffffffff;
56        asm volatile ("getcon   " __TEA ", %0" : "=r" (bh));
57        asm volatile ("getcon   " __TEA ", %0" : "=r" (bl));
58	bh = (bh) >> 32;
59	bl = (bl) & 0xffffffff;
60        asm volatile ("getcon   " __KCR0 ", %0" : "=r" (ch));
61        asm volatile ("getcon   " __KCR0 ", %0" : "=r" (cl));
62	ch = (ch) >> 32;
63	cl = (cl) & 0xffffffff;
64	printk("SR  : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
65	       ah, al, bh, bl, ch, cl);
66
67	ah = (regs->regs[0]) >> 32;
68	al = (regs->regs[0]) & 0xffffffff;
69	bh = (regs->regs[1]) >> 32;
70	bl = (regs->regs[1]) & 0xffffffff;
71	ch = (regs->regs[2]) >> 32;
72	cl = (regs->regs[2]) & 0xffffffff;
73	printk("R0  : %08Lx%08Lx R1  : %08Lx%08Lx R2  : %08Lx%08Lx\n",
74	       ah, al, bh, bl, ch, cl);
75
76	ah = (regs->regs[3]) >> 32;
77	al = (regs->regs[3]) & 0xffffffff;
78	bh = (regs->regs[4]) >> 32;
79	bl = (regs->regs[4]) & 0xffffffff;
80	ch = (regs->regs[5]) >> 32;
81	cl = (regs->regs[5]) & 0xffffffff;
82	printk("R3  : %08Lx%08Lx R4  : %08Lx%08Lx R5  : %08Lx%08Lx\n",
83	       ah, al, bh, bl, ch, cl);
84
85	ah = (regs->regs[6]) >> 32;
86	al = (regs->regs[6]) & 0xffffffff;
87	bh = (regs->regs[7]) >> 32;
88	bl = (regs->regs[7]) & 0xffffffff;
89	ch = (regs->regs[8]) >> 32;
90	cl = (regs->regs[8]) & 0xffffffff;
91	printk("R6  : %08Lx%08Lx R7  : %08Lx%08Lx R8  : %08Lx%08Lx\n",
92	       ah, al, bh, bl, ch, cl);
93
94	ah = (regs->regs[9]) >> 32;
95	al = (regs->regs[9]) & 0xffffffff;
96	bh = (regs->regs[10]) >> 32;
97	bl = (regs->regs[10]) & 0xffffffff;
98	ch = (regs->regs[11]) >> 32;
99	cl = (regs->regs[11]) & 0xffffffff;
100	printk("R9  : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
101	       ah, al, bh, bl, ch, cl);
102
103	ah = (regs->regs[12]) >> 32;
104	al = (regs->regs[12]) & 0xffffffff;
105	bh = (regs->regs[13]) >> 32;
106	bl = (regs->regs[13]) & 0xffffffff;
107	ch = (regs->regs[14]) >> 32;
108	cl = (regs->regs[14]) & 0xffffffff;
109	printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
110	       ah, al, bh, bl, ch, cl);
111
112	ah = (regs->regs[16]) >> 32;
113	al = (regs->regs[16]) & 0xffffffff;
114	bh = (regs->regs[17]) >> 32;
115	bl = (regs->regs[17]) & 0xffffffff;
116	ch = (regs->regs[19]) >> 32;
117	cl = (regs->regs[19]) & 0xffffffff;
118	printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
119	       ah, al, bh, bl, ch, cl);
120
121	ah = (regs->regs[20]) >> 32;
122	al = (regs->regs[20]) & 0xffffffff;
123	bh = (regs->regs[21]) >> 32;
124	bl = (regs->regs[21]) & 0xffffffff;
125	ch = (regs->regs[22]) >> 32;
126	cl = (regs->regs[22]) & 0xffffffff;
127	printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
128	       ah, al, bh, bl, ch, cl);
129
130	ah = (regs->regs[23]) >> 32;
131	al = (regs->regs[23]) & 0xffffffff;
132	bh = (regs->regs[24]) >> 32;
133	bl = (regs->regs[24]) & 0xffffffff;
134	ch = (regs->regs[25]) >> 32;
135	cl = (regs->regs[25]) & 0xffffffff;
136	printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
137	       ah, al, bh, bl, ch, cl);
138
139	ah = (regs->regs[26]) >> 32;
140	al = (regs->regs[26]) & 0xffffffff;
141	bh = (regs->regs[27]) >> 32;
142	bl = (regs->regs[27]) & 0xffffffff;
143	ch = (regs->regs[28]) >> 32;
144	cl = (regs->regs[28]) & 0xffffffff;
145	printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
146	       ah, al, bh, bl, ch, cl);
147
148	ah = (regs->regs[29]) >> 32;
149	al = (regs->regs[29]) & 0xffffffff;
150	bh = (regs->regs[30]) >> 32;
151	bl = (regs->regs[30]) & 0xffffffff;
152	ch = (regs->regs[31]) >> 32;
153	cl = (regs->regs[31]) & 0xffffffff;
154	printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
155	       ah, al, bh, bl, ch, cl);
156
157	ah = (regs->regs[32]) >> 32;
158	al = (regs->regs[32]) & 0xffffffff;
159	bh = (regs->regs[33]) >> 32;
160	bl = (regs->regs[33]) & 0xffffffff;
161	ch = (regs->regs[34]) >> 32;
162	cl = (regs->regs[34]) & 0xffffffff;
163	printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
164	       ah, al, bh, bl, ch, cl);
165
166	ah = (regs->regs[35]) >> 32;
167	al = (regs->regs[35]) & 0xffffffff;
168	bh = (regs->regs[36]) >> 32;
169	bl = (regs->regs[36]) & 0xffffffff;
170	ch = (regs->regs[37]) >> 32;
171	cl = (regs->regs[37]) & 0xffffffff;
172	printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
173	       ah, al, bh, bl, ch, cl);
174
175	ah = (regs->regs[38]) >> 32;
176	al = (regs->regs[38]) & 0xffffffff;
177	bh = (regs->regs[39]) >> 32;
178	bl = (regs->regs[39]) & 0xffffffff;
179	ch = (regs->regs[40]) >> 32;
180	cl = (regs->regs[40]) & 0xffffffff;
181	printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
182	       ah, al, bh, bl, ch, cl);
183
184	ah = (regs->regs[41]) >> 32;
185	al = (regs->regs[41]) & 0xffffffff;
186	bh = (regs->regs[42]) >> 32;
187	bl = (regs->regs[42]) & 0xffffffff;
188	ch = (regs->regs[43]) >> 32;
189	cl = (regs->regs[43]) & 0xffffffff;
190	printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
191	       ah, al, bh, bl, ch, cl);
192
193	ah = (regs->regs[44]) >> 32;
194	al = (regs->regs[44]) & 0xffffffff;
195	bh = (regs->regs[45]) >> 32;
196	bl = (regs->regs[45]) & 0xffffffff;
197	ch = (regs->regs[46]) >> 32;
198	cl = (regs->regs[46]) & 0xffffffff;
199	printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
200	       ah, al, bh, bl, ch, cl);
201
202	ah = (regs->regs[47]) >> 32;
203	al = (regs->regs[47]) & 0xffffffff;
204	bh = (regs->regs[48]) >> 32;
205	bl = (regs->regs[48]) & 0xffffffff;
206	ch = (regs->regs[49]) >> 32;
207	cl = (regs->regs[49]) & 0xffffffff;
208	printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
209	       ah, al, bh, bl, ch, cl);
210
211	ah = (regs->regs[50]) >> 32;
212	al = (regs->regs[50]) & 0xffffffff;
213	bh = (regs->regs[51]) >> 32;
214	bl = (regs->regs[51]) & 0xffffffff;
215	ch = (regs->regs[52]) >> 32;
216	cl = (regs->regs[52]) & 0xffffffff;
217	printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
218	       ah, al, bh, bl, ch, cl);
219
220	ah = (regs->regs[53]) >> 32;
221	al = (regs->regs[53]) & 0xffffffff;
222	bh = (regs->regs[54]) >> 32;
223	bl = (regs->regs[54]) & 0xffffffff;
224	ch = (regs->regs[55]) >> 32;
225	cl = (regs->regs[55]) & 0xffffffff;
226	printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
227	       ah, al, bh, bl, ch, cl);
228
229	ah = (regs->regs[56]) >> 32;
230	al = (regs->regs[56]) & 0xffffffff;
231	bh = (regs->regs[57]) >> 32;
232	bl = (regs->regs[57]) & 0xffffffff;
233	ch = (regs->regs[58]) >> 32;
234	cl = (regs->regs[58]) & 0xffffffff;
235	printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
236	       ah, al, bh, bl, ch, cl);
237
238	ah = (regs->regs[59]) >> 32;
239	al = (regs->regs[59]) & 0xffffffff;
240	bh = (regs->regs[60]) >> 32;
241	bl = (regs->regs[60]) & 0xffffffff;
242	ch = (regs->regs[61]) >> 32;
243	cl = (regs->regs[61]) & 0xffffffff;
244	printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
245	       ah, al, bh, bl, ch, cl);
246
247	ah = (regs->regs[62]) >> 32;
248	al = (regs->regs[62]) & 0xffffffff;
249	bh = (regs->tregs[0]) >> 32;
250	bl = (regs->tregs[0]) & 0xffffffff;
251	ch = (regs->tregs[1]) >> 32;
252	cl = (regs->tregs[1]) & 0xffffffff;
253	printk("R62 : %08Lx%08Lx T0  : %08Lx%08Lx T1  : %08Lx%08Lx\n",
254	       ah, al, bh, bl, ch, cl);
255
256	ah = (regs->tregs[2]) >> 32;
257	al = (regs->tregs[2]) & 0xffffffff;
258	bh = (regs->tregs[3]) >> 32;
259	bl = (regs->tregs[3]) & 0xffffffff;
260	ch = (regs->tregs[4]) >> 32;
261	cl = (regs->tregs[4]) & 0xffffffff;
262	printk("T2  : %08Lx%08Lx T3  : %08Lx%08Lx T4  : %08Lx%08Lx\n",
263	       ah, al, bh, bl, ch, cl);
264
265	ah = (regs->tregs[5]) >> 32;
266	al = (regs->tregs[5]) & 0xffffffff;
267	bh = (regs->tregs[6]) >> 32;
268	bl = (regs->tregs[6]) & 0xffffffff;
269	ch = (regs->tregs[7]) >> 32;
270	cl = (regs->tregs[7]) & 0xffffffff;
271	printk("T5  : %08Lx%08Lx T6  : %08Lx%08Lx T7  : %08Lx%08Lx\n",
272	       ah, al, bh, bl, ch, cl);
273
274	/*
275	 * If we're in kernel mode, dump the stack too..
276	 */
277	if (!user_mode(regs)) {
278		void show_stack(struct task_struct *tsk, unsigned long *sp);
279		unsigned long sp = regs->regs[15] & 0xffffffff;
280		struct task_struct *tsk = get_current();
281
282		tsk->thread.kregs = regs;
283
284		show_stack(tsk, (unsigned long *)sp);
285	}
286}
287
288/*
289 * Free current thread data structures etc..
290 */
291void exit_thread(void)
292{
293	/*
294	 * See arch/sparc/kernel/process.c for the precedent for doing
295	 * this -- RPC.
296	 *
297	 * The SH-5 FPU save/restore approach relies on
298	 * last_task_used_math pointing to a live task_struct.  When
299	 * another task tries to use the FPU for the 1st time, the FPUDIS
300	 * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
301	 * existing FPU state to the FP regs field within
302	 * last_task_used_math before re-loading the new task's FPU state
303	 * (or initialising it if the FPU has been used before).  So if
304	 * last_task_used_math is stale, and its page has already been
305	 * re-allocated for another use, the consequences are rather
306	 * grim. Unless we null it here, there is no other path through
307	 * which it would get safely nulled.
308	 */
309#ifdef CONFIG_SH_FPU
310	if (last_task_used_math == current) {
311		last_task_used_math = NULL;
312	}
313#endif
314}
315
316void flush_thread(void)
317{
318
319	/* Called by fs/exec.c (setup_new_exec) to remove traces of a
320	 * previously running executable. */
321#ifdef CONFIG_SH_FPU
322	if (last_task_used_math == current) {
323		last_task_used_math = NULL;
324	}
325	/* Force FPU state to be reinitialised after exec */
326	clear_used_math();
327#endif
328
329	/* if we are a kernel thread, about to change to user thread,
330         * update kreg
331         */
332	if(current->thread.kregs==&fake_swapper_regs) {
333          current->thread.kregs =
334             ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
335	  current->thread.uregs = current->thread.kregs;
336	}
337}
338
339void release_thread(struct task_struct *dead_task)
340{
341	/* do nothing */
342}
343
344/* Fill in the fpu structure for a core dump.. */
345int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
346{
347#ifdef CONFIG_SH_FPU
348	int fpvalid;
349	struct task_struct *tsk = current;
350
351	fpvalid = !!tsk_used_math(tsk);
352	if (fpvalid) {
353		if (current == last_task_used_math) {
354			enable_fpu();
355			save_fpu(tsk);
356			disable_fpu();
357			last_task_used_math = 0;
358			regs->sr |= SR_FD;
359		}
360
361		memcpy(fpu, &tsk->thread.xstate->hardfpu, sizeof(*fpu));
362	}
363
364	return fpvalid;
365#else
366	return 0; /* Task didn't use the fpu at all. */
367#endif
368}
369EXPORT_SYMBOL(dump_fpu);
370
371asmlinkage void ret_from_fork(void);
372asmlinkage void ret_from_kernel_thread(void);
373
374int copy_thread(unsigned long clone_flags, unsigned long usp,
375		unsigned long arg, struct task_struct *p)
376{
377	struct pt_regs *childregs;
378
379#ifdef CONFIG_SH_FPU
380	/* can't happen for a kernel thread */
381	if (last_task_used_math == current) {
382		enable_fpu();
383		save_fpu(current);
384		disable_fpu();
385		last_task_used_math = NULL;
386		current_pt_regs()->sr |= SR_FD;
387	}
388#endif
389	/* Copy from sh version */
390	childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
391	p->thread.sp = (unsigned long) childregs;
392
393	if (unlikely(p->flags & PF_KTHREAD)) {
394		memset(childregs, 0, sizeof(struct pt_regs));
395		childregs->regs[2] = (unsigned long)arg;
396		childregs->regs[3] = (unsigned long)usp;
397		childregs->sr = (1 << 30); /* not user_mode */
398		childregs->sr |= SR_FD; /* Invalidate FPU flag */
399		p->thread.pc = (unsigned long) ret_from_kernel_thread;
400		return 0;
401	}
402	*childregs = *current_pt_regs();
403
404	/*
405	 * Sign extend the edited stack.
406	 * Note that thread.pc and thread.pc will stay
407	 * 32-bit wide and context switch must take care
408	 * of NEFF sign extension.
409	 */
410	if (usp)
411		childregs->regs[15] = neff_sign_extend(usp);
412	p->thread.uregs = childregs;
413
414	childregs->regs[9] = 0; /* Set return value for child */
415	childregs->sr |= SR_FD; /* Invalidate FPU flag */
416
417	p->thread.pc = (unsigned long) ret_from_fork;
418
419	return 0;
420}
421
422#ifdef CONFIG_FRAME_POINTER
423static int in_sh64_switch_to(unsigned long pc)
424{
425	extern char __sh64_switch_to_end;
426	/* For a sleeping task, the PC is somewhere in the middle of the function,
427	   so we don't have to worry about masking the LSB off */
428	return (pc >= (unsigned long) sh64_switch_to) &&
429	       (pc < (unsigned long) &__sh64_switch_to_end);
430}
431#endif
432
433unsigned long get_wchan(struct task_struct *p)
434{
435	unsigned long pc;
436
437	if (!p || p == current || p->state == TASK_RUNNING)
438		return 0;
439
440	/*
441	 * The same comment as on the Alpha applies here, too ...
442	 */
443	pc = thread_saved_pc(p);
444
445#ifdef CONFIG_FRAME_POINTER
446	if (in_sh64_switch_to(pc)) {
447		unsigned long schedule_fp;
448		unsigned long sh64_switch_to_fp;
449		unsigned long schedule_caller_pc;
450
451		sh64_switch_to_fp = (long) p->thread.sp;
452		/* r14 is saved at offset 4 in the sh64_switch_to frame */
453		schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
454
455		/* and the caller of 'schedule' is (currently!) saved at offset 24
456		   in the frame of schedule (from disasm) */
457		schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
458		return schedule_caller_pc;
459	}
460#endif
461	return pc;
462}
463