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[PATCH] sched: resched and cpu_idle rework
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1da177e4
LT		 1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * arch/sh64/kernel/process.c
7 *
8 * Copyright (C) 2000, 2001 Paolo Alberelli
9 * Copyright (C) 2003 Paul Mundt
10 * Copyright (C) 2003, 2004 Richard Curnow
11 *
12 * Started from SH3/4 version:
13 * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
14 *
15 * In turn started from i386 version:
16 * Copyright (C) 1995 Linus Torvalds
17 *
18 */
19
20/*
21 * This file handles the architecture-dependent parts of process handling..
22 */
23
24/* Temporary flags/tests. All to be removed/undefined. BEGIN */
25#define IDLE_TRACE
26#define VM_SHOW_TABLES
27#define VM_TEST_FAULT
28#define VM_TEST_RTLBMISS
29#define VM_TEST_WTLBMISS
30
31#undef VM_SHOW_TABLES
32#undef IDLE_TRACE
33/* Temporary flags/tests. All to be removed/undefined. END */
34
35#define __KERNEL_SYSCALLS__
36#include <stdarg.h>
37
38#include <linux/config.h>
39#include <linux/kernel.h>
40#include <linux/rwsem.h>
41#include <linux/mm.h>
42#include <linux/smp.h>
43#include <linux/smp_lock.h>
44#include <linux/ptrace.h>
45#include <linux/slab.h>
46#include <linux/vmalloc.h>
47#include <linux/user.h>
48#include <linux/a.out.h>
49#include <linux/interrupt.h>
50#include <linux/unistd.h>
51#include <linux/delay.h>
52#include <linux/reboot.h>
53#include <linux/init.h>
54
55#include <asm/uaccess.h>
56#include <asm/pgtable.h>
57#include <asm/system.h>
58#include <asm/io.h>
59#include <asm/processor.h> /* includes also <asm/registers.h> */
60#include <asm/mmu_context.h>
61#include <asm/elf.h>
62#include <asm/page.h>
63
64#include <linux/irq.h>
65
66struct task_struct *last_task_used_math = NULL;
67
68#ifdef IDLE_TRACE
69#ifdef VM_SHOW_TABLES
70/* For testing */
71static void print_PTE(long base)
72{
73 int i, skip=0;
74 long long x, y, *p = (long long *) base;
75
76 for (i=0; i< 512; i++, p++){
77 if (*p == 0) {
78 if (!skip) {
79 skip++;
80 printk("(0s) ");
81 }
82 } else {
83 skip=0;
84 x = (*p) >> 32;
85 y = (*p) & 0xffffffff;
86 printk("%08Lx%08Lx ", x, y);
87 if (!((i+1)&0x3)) printk("\n");
88 }
89 }
90}
91
92/* For testing */
93static void print_DIR(long base)
94{
95 int i, skip=0;
96 long *p = (long *) base;
97
98 for (i=0; i< 512; i++, p++){
99 if (*p == 0) {
100 if (!skip) {
101 skip++;
102 printk("(0s) ");
103 }
104 } else {
105 skip=0;
106 printk("%08lx ", *p);
107 if (!((i+1)&0x7)) printk("\n");
108 }
109 }
110}
111
112/* For testing */
113static void print_vmalloc_first_tables(void)
114{
115
116#define PRESENT 0x800 /* Bit 11 */
117
118 /*
119 * Do it really dirty by looking at raw addresses,
120 * raw offsets, no types. If we used pgtable/pgalloc
121 * macros/definitions we could hide potential bugs.
122 *
123 * Note that pointers are 32-bit for CDC.
124 */
125 long pgdt, pmdt, ptet;
126
127 pgdt = (long) &swapper_pg_dir;
128 printk("-->PGD (0x%08lx):\n", pgdt);
129 print_DIR(pgdt);
130 printk("\n");
131
132 /* VMALLOC pool is mapped at 0xc0000000, second (pointer) entry in PGD */
133 pgdt += 4;
134 pmdt = (long) (* (long *) pgdt);
135 if (!(pmdt & PRESENT)) {
136 printk("No PMD\n");
137 return;
138 } else pmdt &= 0xfffff000;
139
140 printk("-->PMD (0x%08lx):\n", pmdt);
141 print_DIR(pmdt);
142 printk("\n");
143
144 /* Get the pmdt displacement for 0xc0000000 */
145 pmdt += 2048;
146
147 /* just look at first two address ranges ... */
148 /* ... 0xc0000000 ... */
149 ptet = (long) (* (long *) pmdt);
150 if (!(ptet & PRESENT)) {
151 printk("No PTE0\n");
152 return;
153 } else ptet &= 0xfffff000;
154
155 printk("-->PTE0 (0x%08lx):\n", ptet);
156 print_PTE(ptet);
157 printk("\n");
158
159 /* ... 0xc0001000 ... */
160 ptet += 4;
161 if (!(ptet & PRESENT)) {
162 printk("No PTE1\n");
163 return;
164 } else ptet &= 0xfffff000;
165 printk("-->PTE1 (0x%08lx):\n", ptet);
166 print_PTE(ptet);
167 printk("\n");
168}
169#else
170#define print_vmalloc_first_tables()
171#endif /* VM_SHOW_TABLES */
172
173static void test_VM(void)
174{
175 void *a, *b, *c;
176
177#ifdef VM_SHOW_TABLES
178 printk("Initial PGD/PMD/PTE\n");
179#endif
180 print_vmalloc_first_tables();
181
182 printk("Allocating 2 bytes\n");
183 a = vmalloc(2);
184 print_vmalloc_first_tables();
185
186 printk("Allocating 4100 bytes\n");
187 b = vmalloc(4100);
188 print_vmalloc_first_tables();
189
190 printk("Allocating 20234 bytes\n");
191 c = vmalloc(20234);
192 print_vmalloc_first_tables();
193
194#ifdef VM_TEST_FAULT
195 /* Here you may want to fault ! */
196
197#ifdef VM_TEST_RTLBMISS
198 printk("Ready to fault upon read.\n");
199 if (* (char *) a) {
200 printk("RTLBMISSed on area a !\n");
201 }
202 printk("RTLBMISSed on area a !\n");
203#endif
204
205#ifdef VM_TEST_WTLBMISS
206 printk("Ready to fault upon write.\n");
207 *((char *) b) = 'L';
208 printk("WTLBMISSed on area b !\n");
209#endif
210
211#endif /* VM_TEST_FAULT */
212
213 printk("Deallocating the 4100 byte chunk\n");
214 vfree(b);
215 print_vmalloc_first_tables();
216
217 printk("Deallocating the 2 byte chunk\n");
218 vfree(a);
219 print_vmalloc_first_tables();
220
221 printk("Deallocating the last chunk\n");
222 vfree(c);
223 print_vmalloc_first_tables();
224}
225
226extern unsigned long volatile jiffies;
227int once = 0;
228unsigned long old_jiffies;
229int pid = -1, pgid = -1;
230
231void idle_trace(void)
232{
233
234 _syscall0(int, getpid)
235 _syscall1(int, getpgid, int, pid)
236
237 if (!once) {
238 /* VM allocation/deallocation simple test */
239 test_VM();
240 pid = getpid();
241
242 printk("Got all through to Idle !!\n");
243 printk("I'm now going to loop forever ...\n");
244 printk("Any ! below is a timer tick.\n");
245 printk("Any . below is a getpgid system call from pid = %d.\n", pid);
246
247
248 old_jiffies = jiffies;
249 once++;
250 }
251
252 if (old_jiffies != jiffies) {
253 old_jiffies = jiffies - old_jiffies;
254 switch (old_jiffies) {
255 case 1:
256 printk("!");
257 break;
258 case 2:
259 printk("!!");
260 break;
261 case 3:
262 printk("!!!");
263 break;
264 case 4:
265 printk("!!!!");
266 break;
267 default:
268 printk("(%d!)", (int) old_jiffies);
269 }
270 old_jiffies = jiffies;
271 }
272 pgid = getpgid(pid);
273 printk(".");
274}
275#else
276#define idle_trace() do { } while (0)
277#endif /* IDLE_TRACE */
278
279static int hlt_counter = 1;
280
281#define HARD_IDLE_TIMEOUT (HZ / 3)
282
283void disable_hlt(void)
284{
285 hlt_counter++;
286}
287
288void enable_hlt(void)
289{
290 hlt_counter--;
291}
292
293static int __init nohlt_setup(char *__unused)
294{
295 hlt_counter = 1;
296 return 1;
297}
298
299static int __init hlt_setup(char *__unused)
300{
301 hlt_counter = 0;
302 return 1;
303}
304
305__setup("nohlt", nohlt_setup);
306__setup("hlt", hlt_setup);
307
308static inline void hlt(void)
309{
1da177e4
LT		 310 __asm__ __volatile__ ("sleep" : : : "memory");
311}
312
313/*
314 * The idle loop on a uniprocessor SH..
315 */
64c7c8f8 316void cpu_idle(void)
1da177e4
LT		 317{
318 /* endless idle loop with no priority at all */
319 while (1) {
320 if (hlt_counter) {
64c7c8f8
NP		 321 while (!need_resched())
322 cpu_relax();
1da177e4
LT		 323 } else {
324 local_irq_disable();
325 while (!need_resched()) {
326 local_irq_enable();
327 idle_trace();
328 hlt();
329 local_irq_disable();
330 }
331 local_irq_enable();
332 }
5bfb5d69 333 preempt_enable_no_resched();
1da177e4 334 schedule();
5bfb5d69 335 preempt_disable();
1da177e4 336 }
1da177e4 337
1da177e4
LT		 338}
339
340void machine_restart(char * __unused)
341{
342 extern void phys_stext(void);
343
344 phys_stext();
345}
346
347void machine_halt(void)
348{
349 for (;;);
350}
351
352void machine_power_off(void)
353{
354 extern void enter_deep_standby(void);
355
356 enter_deep_standby();
357}
358
359void show_regs(struct pt_regs * regs)
360{
361 unsigned long long ah, al, bh, bl, ch, cl;
362
363 printk("\n");
364
365 ah = (regs->pc) >> 32;
366 al = (regs->pc) & 0xffffffff;
367 bh = (regs->regs[18]) >> 32;
368 bl = (regs->regs[18]) & 0xffffffff;
369 ch = (regs->regs[15]) >> 32;
370 cl = (regs->regs[15]) & 0xffffffff;
371 printk("PC : %08Lx%08Lx LINK: %08Lx%08Lx SP : %08Lx%08Lx\n",
372 ah, al, bh, bl, ch, cl);
373
374 ah = (regs->sr) >> 32;
375 al = (regs->sr) & 0xffffffff;
376 asm volatile ("getcon " __TEA ", %0" : "=r" (bh));
377 asm volatile ("getcon " __TEA ", %0" : "=r" (bl));
378 bh = (bh) >> 32;
379 bl = (bl) & 0xffffffff;
380 asm volatile ("getcon " __KCR0 ", %0" : "=r" (ch));
381 asm volatile ("getcon " __KCR0 ", %0" : "=r" (cl));
382 ch = (ch) >> 32;
383 cl = (cl) & 0xffffffff;
384 printk("SR : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
385 ah, al, bh, bl, ch, cl);
386
387 ah = (regs->regs[0]) >> 32;
388 al = (regs->regs[0]) & 0xffffffff;
389 bh = (regs->regs[1]) >> 32;
390 bl = (regs->regs[1]) & 0xffffffff;
391 ch = (regs->regs[2]) >> 32;
392 cl = (regs->regs[2]) & 0xffffffff;
393 printk("R0 : %08Lx%08Lx R1 : %08Lx%08Lx R2 : %08Lx%08Lx\n",
394 ah, al, bh, bl, ch, cl);
395
396 ah = (regs->regs[3]) >> 32;
397 al = (regs->regs[3]) & 0xffffffff;
398 bh = (regs->regs[4]) >> 32;
399 bl = (regs->regs[4]) & 0xffffffff;
400 ch = (regs->regs[5]) >> 32;
401 cl = (regs->regs[5]) & 0xffffffff;
402 printk("R3 : %08Lx%08Lx R4 : %08Lx%08Lx R5 : %08Lx%08Lx\n",
403 ah, al, bh, bl, ch, cl);
404
405 ah = (regs->regs[6]) >> 32;
406 al = (regs->regs[6]) & 0xffffffff;
407 bh = (regs->regs[7]) >> 32;
408 bl = (regs->regs[7]) & 0xffffffff;
409 ch = (regs->regs[8]) >> 32;
410 cl = (regs->regs[8]) & 0xffffffff;
411 printk("R6 : %08Lx%08Lx R7 : %08Lx%08Lx R8 : %08Lx%08Lx\n",
412 ah, al, bh, bl, ch, cl);
413
414 ah = (regs->regs[9]) >> 32;
415 al = (regs->regs[9]) & 0xffffffff;
416 bh = (regs->regs[10]) >> 32;
417 bl = (regs->regs[10]) & 0xffffffff;
418 ch = (regs->regs[11]) >> 32;
419 cl = (regs->regs[11]) & 0xffffffff;
420 printk("R9 : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
421 ah, al, bh, bl, ch, cl);
422
423 ah = (regs->regs[12]) >> 32;
424 al = (regs->regs[12]) & 0xffffffff;
425 bh = (regs->regs[13]) >> 32;
426 bl = (regs->regs[13]) & 0xffffffff;
427 ch = (regs->regs[14]) >> 32;
428 cl = (regs->regs[14]) & 0xffffffff;
429 printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
430 ah, al, bh, bl, ch, cl);
431
432 ah = (regs->regs[16]) >> 32;
433 al = (regs->regs[16]) & 0xffffffff;
434 bh = (regs->regs[17]) >> 32;
435 bl = (regs->regs[17]) & 0xffffffff;
436 ch = (regs->regs[19]) >> 32;
437 cl = (regs->regs[19]) & 0xffffffff;
438 printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
439 ah, al, bh, bl, ch, cl);
440
441 ah = (regs->regs[20]) >> 32;
442 al = (regs->regs[20]) & 0xffffffff;
443 bh = (regs->regs[21]) >> 32;
444 bl = (regs->regs[21]) & 0xffffffff;
445 ch = (regs->regs[22]) >> 32;
446 cl = (regs->regs[22]) & 0xffffffff;
447 printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
448 ah, al, bh, bl, ch, cl);
449
450 ah = (regs->regs[23]) >> 32;
451 al = (regs->regs[23]) & 0xffffffff;
452 bh = (regs->regs[24]) >> 32;
453 bl = (regs->regs[24]) & 0xffffffff;
454 ch = (regs->regs[25]) >> 32;
455 cl = (regs->regs[25]) & 0xffffffff;
456 printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
457 ah, al, bh, bl, ch, cl);
458
459 ah = (regs->regs[26]) >> 32;
460 al = (regs->regs[26]) & 0xffffffff;
461 bh = (regs->regs[27]) >> 32;
462 bl = (regs->regs[27]) & 0xffffffff;
463 ch = (regs->regs[28]) >> 32;
464 cl = (regs->regs[28]) & 0xffffffff;
465 printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
466 ah, al, bh, bl, ch, cl);
467
468 ah = (regs->regs[29]) >> 32;
469 al = (regs->regs[29]) & 0xffffffff;
470 bh = (regs->regs[30]) >> 32;
471 bl = (regs->regs[30]) & 0xffffffff;
472 ch = (regs->regs[31]) >> 32;
473 cl = (regs->regs[31]) & 0xffffffff;
474 printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
475 ah, al, bh, bl, ch, cl);
476
477 ah = (regs->regs[32]) >> 32;
478 al = (regs->regs[32]) & 0xffffffff;
479 bh = (regs->regs[33]) >> 32;
480 bl = (regs->regs[33]) & 0xffffffff;
481 ch = (regs->regs[34]) >> 32;
482 cl = (regs->regs[34]) & 0xffffffff;
483 printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
484 ah, al, bh, bl, ch, cl);
485
486 ah = (regs->regs[35]) >> 32;
487 al = (regs->regs[35]) & 0xffffffff;
488 bh = (regs->regs[36]) >> 32;
489 bl = (regs->regs[36]) & 0xffffffff;
490 ch = (regs->regs[37]) >> 32;
491 cl = (regs->regs[37]) & 0xffffffff;
492 printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
493 ah, al, bh, bl, ch, cl);
494
495 ah = (regs->regs[38]) >> 32;
496 al = (regs->regs[38]) & 0xffffffff;
497 bh = (regs->regs[39]) >> 32;
498 bl = (regs->regs[39]) & 0xffffffff;
499 ch = (regs->regs[40]) >> 32;
500 cl = (regs->regs[40]) & 0xffffffff;
501 printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
502 ah, al, bh, bl, ch, cl);
503
504 ah = (regs->regs[41]) >> 32;
505 al = (regs->regs[41]) & 0xffffffff;
506 bh = (regs->regs[42]) >> 32;
507 bl = (regs->regs[42]) & 0xffffffff;
508 ch = (regs->regs[43]) >> 32;
509 cl = (regs->regs[43]) & 0xffffffff;
510 printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
511 ah, al, bh, bl, ch, cl);
512
513 ah = (regs->regs[44]) >> 32;
514 al = (regs->regs[44]) & 0xffffffff;
515 bh = (regs->regs[45]) >> 32;
516 bl = (regs->regs[45]) & 0xffffffff;
517 ch = (regs->regs[46]) >> 32;
518 cl = (regs->regs[46]) & 0xffffffff;
519 printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
520 ah, al, bh, bl, ch, cl);
521
522 ah = (regs->regs[47]) >> 32;
523 al = (regs->regs[47]) & 0xffffffff;
524 bh = (regs->regs[48]) >> 32;
525 bl = (regs->regs[48]) & 0xffffffff;
526 ch = (regs->regs[49]) >> 32;
527 cl = (regs->regs[49]) & 0xffffffff;
528 printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
529 ah, al, bh, bl, ch, cl);
530
531 ah = (regs->regs[50]) >> 32;
532 al = (regs->regs[50]) & 0xffffffff;
533 bh = (regs->regs[51]) >> 32;
534 bl = (regs->regs[51]) & 0xffffffff;
535 ch = (regs->regs[52]) >> 32;
536 cl = (regs->regs[52]) & 0xffffffff;
537 printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
538 ah, al, bh, bl, ch, cl);
539
540 ah = (regs->regs[53]) >> 32;
541 al = (regs->regs[53]) & 0xffffffff;
542 bh = (regs->regs[54]) >> 32;
543 bl = (regs->regs[54]) & 0xffffffff;
544 ch = (regs->regs[55]) >> 32;
545 cl = (regs->regs[55]) & 0xffffffff;
546 printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
547 ah, al, bh, bl, ch, cl);
548
549 ah = (regs->regs[56]) >> 32;
550 al = (regs->regs[56]) & 0xffffffff;
551 bh = (regs->regs[57]) >> 32;
552 bl = (regs->regs[57]) & 0xffffffff;
553 ch = (regs->regs[58]) >> 32;
554 cl = (regs->regs[58]) & 0xffffffff;
555 printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
556 ah, al, bh, bl, ch, cl);
557
558 ah = (regs->regs[59]) >> 32;
559 al = (regs->regs[59]) & 0xffffffff;
560 bh = (regs->regs[60]) >> 32;
561 bl = (regs->regs[60]) & 0xffffffff;
562 ch = (regs->regs[61]) >> 32;
563 cl = (regs->regs[61]) & 0xffffffff;
564 printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
565 ah, al, bh, bl, ch, cl);
566
567 ah = (regs->regs[62]) >> 32;
568 al = (regs->regs[62]) & 0xffffffff;
569 bh = (regs->tregs[0]) >> 32;
570 bl = (regs->tregs[0]) & 0xffffffff;
571 ch = (regs->tregs[1]) >> 32;
572 cl = (regs->tregs[1]) & 0xffffffff;
573 printk("R62 : %08Lx%08Lx T0 : %08Lx%08Lx T1 : %08Lx%08Lx\n",
574 ah, al, bh, bl, ch, cl);
575
576 ah = (regs->tregs[2]) >> 32;
577 al = (regs->tregs[2]) & 0xffffffff;
578 bh = (regs->tregs[3]) >> 32;
579 bl = (regs->tregs[3]) & 0xffffffff;
580 ch = (regs->tregs[4]) >> 32;
581 cl = (regs->tregs[4]) & 0xffffffff;
582 printk("T2 : %08Lx%08Lx T3 : %08Lx%08Lx T4 : %08Lx%08Lx\n",
583 ah, al, bh, bl, ch, cl);
584
585 ah = (regs->tregs[5]) >> 32;
586 al = (regs->tregs[5]) & 0xffffffff;
587 bh = (regs->tregs[6]) >> 32;
588 bl = (regs->tregs[6]) & 0xffffffff;
589 ch = (regs->tregs[7]) >> 32;
590 cl = (regs->tregs[7]) & 0xffffffff;
591 printk("T5 : %08Lx%08Lx T6 : %08Lx%08Lx T7 : %08Lx%08Lx\n",
592 ah, al, bh, bl, ch, cl);
593
594 /*
595 * If we're in kernel mode, dump the stack too..
596 */
597 if (!user_mode(regs)) {
598 void show_stack(struct task_struct *tsk, unsigned long *sp);
599 unsigned long sp = regs->regs[15] & 0xffffffff;
600 struct task_struct *tsk = get_current();
601
602 tsk->thread.kregs = regs;
603
604 show_stack(tsk, (unsigned long *)sp);
605 }
606}
607
608struct task_struct * alloc_task_struct(void)
609{
610 /* Get task descriptor pages */
611 return (struct task_struct *)
612 __get_free_pages(GFP_KERNEL, get_order(THREAD_SIZE));
613}
614
615void free_task_struct(struct task_struct *p)
616{
617 free_pages((unsigned long) p, get_order(THREAD_SIZE));
618}
619
620/*
621 * Create a kernel thread
622 */
623
624/*
625 * This is the mechanism for creating a new kernel thread.
626 *
627 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
628 * who haven't done an "execve()") should use this: it will work within
629 * a system call from a "real" process, but the process memory space will
630 * not be free'd until both the parent and the child have exited.
631 */
632int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
633{
634 /* A bit less processor dependent than older sh ... */
635 unsigned int reply;
636
637static __inline__ _syscall2(int,clone,unsigned long,flags,unsigned long,newsp)
638static __inline__ _syscall1(int,exit,int,ret)
639
640 reply = clone(flags | CLONE_VM, 0);
641 if (!reply) {
642 /* Child */
643 reply = exit(fn(arg));
644 }
645
646 return reply;
647}
648
649/*
650 * Free current thread data structures etc..
651 */
652void exit_thread(void)
653{
654 /* See arch/sparc/kernel/process.c for the precedent for doing this -- RPC.
655
656 The SH-5 FPU save/restore approach relies on last_task_used_math
657 pointing to a live task_struct. When another task tries to use the
658 FPU for the 1st time, the FPUDIS trap handling (see
659 arch/sh64/kernel/fpu.c) will save the existing FPU state to the
660 FP regs field within last_task_used_math before re-loading the new
661 task's FPU state (or initialising it if the FPU has been used
662 before). So if last_task_used_math is stale, and its page has already been
663 re-allocated for another use, the consequences are rather grim. Unless we
664 null it here, there is no other path through which it would get safely
665 nulled. */
666
667#ifdef CONFIG_SH_FPU
668 if (last_task_used_math == current) {
669 last_task_used_math = NULL;
670 }
671#endif
672}
673
674void flush_thread(void)
675{
676
677 /* Called by fs/exec.c (flush_old_exec) to remove traces of a
678 * previously running executable. */
679#ifdef CONFIG_SH_FPU
680 if (last_task_used_math == current) {
681 last_task_used_math = NULL;
682 }
683 /* Force FPU state to be reinitialised after exec */
684 clear_used_math();
685#endif
686
687 /* if we are a kernel thread, about to change to user thread,
688 * update kreg
689 */
690 if(current->thread.kregs==&fake_swapper_regs) {
691 current->thread.kregs =
692 ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
693 current->thread.uregs = current->thread.kregs;
694 }
695}
696
697void release_thread(struct task_struct *dead_task)
698{
699 /* do nothing */
700}
701
702/* Fill in the fpu structure for a core dump.. */
703int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
704{
705#ifdef CONFIG_SH_FPU
706 int fpvalid;
707 struct task_struct *tsk = current;
708
709 fpvalid = !!tsk_used_math(tsk);
710 if (fpvalid) {
711 if (current == last_task_used_math) {
712 grab_fpu();
713 fpsave(&tsk->thread.fpu.hard);
714 release_fpu();
715 last_task_used_math = 0;
716 regs->sr |= SR_FD;
717 }
718
719 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
720 }
721
722 return fpvalid;
723#else
724 return 0; /* Task didn't use the fpu at all. */
725#endif
726}
727
728asmlinkage void ret_from_fork(void);
729
730int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
731 unsigned long unused,
732 struct task_struct *p, struct pt_regs *regs)
733{
734 struct pt_regs *childregs;
735 unsigned long long se; /* Sign extension */
736
737#ifdef CONFIG_SH_FPU
738 if(last_task_used_math == current) {
739 grab_fpu();
740 fpsave(&current->thread.fpu.hard);
741 release_fpu();
742 last_task_used_math = NULL;
743 regs->sr |= SR_FD;
744 }
745#endif
746 /* Copy from sh version */
747 childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long) p->thread_info )) - 1;
748
749 *childregs = *regs;
750
751 if (user_mode(regs)) {
752 childregs->regs[15] = usp;
753 p->thread.uregs = childregs;
754 } else {
755 childregs->regs[15] = (unsigned long)p->thread_info + THREAD_SIZE;
756 }
757
758 childregs->regs[9] = 0; /* Set return value for child */
759 childregs->sr |= SR_FD; /* Invalidate FPU flag */
760
761 p->thread.sp = (unsigned long) childregs;
762 p->thread.pc = (unsigned long) ret_from_fork;
763
764 /*
765 * Sign extend the edited stack.
766 * Note that thread.pc and thread.pc will stay
767 * 32-bit wide and context switch must take care
768 * of NEFF sign extension.
769 */
770
771 se = childregs->regs[15];
772 se = (se & NEFF_SIGN) ? (se | NEFF_MASK) : se;
773 childregs->regs[15] = se;
774
775 return 0;
776}
777
778/*
779 * fill in the user structure for a core dump..
780 */
781void dump_thread(struct pt_regs * regs, struct user * dump)
782{
783 dump->magic = CMAGIC;
784 dump->start_code = current->mm->start_code;
785 dump->start_data = current->mm->start_data;
786 dump->start_stack = regs->regs[15] & ~(PAGE_SIZE - 1);
787 dump->u_tsize = (current->mm->end_code - dump->start_code) >> PAGE_SHIFT;
788 dump->u_dsize = (current->mm->brk + (PAGE_SIZE-1) - dump->start_data) >> PAGE_SHIFT;
789 dump->u_ssize = (current->mm->start_stack - dump->start_stack +
790 PAGE_SIZE - 1) >> PAGE_SHIFT;
791 /* Debug registers will come here. */
792
793 dump->regs = *regs;
794
795 dump->u_fpvalid = dump_fpu(regs, &dump->fpu);
796}
797
798asmlinkage int sys_fork(unsigned long r2, unsigned long r3,
799 unsigned long r4, unsigned long r5,
800 unsigned long r6, unsigned long r7,
801 struct pt_regs *pregs)
802{
803 return do_fork(SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
804}
805
806asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
807 unsigned long r4, unsigned long r5,
808 unsigned long r6, unsigned long r7,
809 struct pt_regs *pregs)
810{
811 if (!newsp)
812 newsp = pregs->regs[15];
813 return do_fork(clone_flags, newsp, pregs, 0, 0, 0);
814}
815
816/*
817 * This is trivial, and on the face of it looks like it
818 * could equally well be done in user mode.
819 *
820 * Not so, for quite unobvious reasons - register pressure.
821 * In user mode vfork() cannot have a stack frame, and if
822 * done by calling the "clone()" system call directly, you
823 * do not have enough call-clobbered registers to hold all
824 * the information you need.
825 */
826asmlinkage int sys_vfork(unsigned long r2, unsigned long r3,
827 unsigned long r4, unsigned long r5,
828 unsigned long r6, unsigned long r7,
829 struct pt_regs *pregs)
830{
831 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
832}
833
834/*
835 * sys_execve() executes a new program.
836 */
837asmlinkage int sys_execve(char *ufilename, char **uargv,
838 char **uenvp, unsigned long r5,
839 unsigned long r6, unsigned long r7,
840 struct pt_regs *pregs)
841{
842 int error;
843 char *filename;
844
845 lock_kernel();
846 filename = getname((char __user *)ufilename);
847 error = PTR_ERR(filename);
848 if (IS_ERR(filename))
849 goto out;
850
851 error = do_execve(filename,
852 (char __user * __user *)uargv,
853 (char __user * __user *)uenvp,
854 pregs);
855 if (error == 0) {
856 task_lock(current);
857 current->ptrace &= ~PT_DTRACE;
858 task_unlock(current);
859 }
860 putname(filename);
861out:
862 unlock_kernel();
863 return error;
864}
865
866/*
867 * These bracket the sleeping functions..
868 */
869extern void interruptible_sleep_on(wait_queue_head_t *q);
870
871#define mid_sched ((unsigned long) interruptible_sleep_on)
872
873static int in_sh64_switch_to(unsigned long pc)
874{
875 extern char __sh64_switch_to_end;
876 /* For a sleeping task, the PC is somewhere in the middle of the function,
877 so we don't have to worry about masking the LSB off */
878 return (pc >= (unsigned long) sh64_switch_to) &&
879 (pc < (unsigned long) &__sh64_switch_to_end);
880}
881
882unsigned long get_wchan(struct task_struct *p)
883{
884 unsigned long schedule_fp;
885 unsigned long sh64_switch_to_fp;
886 unsigned long schedule_caller_pc;
887 unsigned long pc;
888
889 if (!p || p == current || p->state == TASK_RUNNING)
890 return 0;
891
892 /*
893 * The same comment as on the Alpha applies here, too ...
894 */
895 pc = thread_saved_pc(p);
896
897#ifdef CONFIG_FRAME_POINTER
898 if (in_sh64_switch_to(pc)) {
899 sh64_switch_to_fp = (long) p->thread.sp;
900 /* r14 is saved at offset 4 in the sh64_switch_to frame */
901 schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
902
903 /* and the caller of 'schedule' is (currently!) saved at offset 24
904 in the frame of schedule (from disasm) */
905 schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
906 return schedule_caller_pc;
907 }
908#endif
909 return pc;
910}
911
912/* Provide a /proc/asids file that lists out the
913 ASIDs currently associated with the processes. (If the DM.PC register is
914 examined through the debug link, this shows ASID + PC. To make use of this,
915 the PID->ASID relationship needs to be known. This is primarily for
916 debugging.)
917 */
918
919#if defined(CONFIG_SH64_PROC_ASIDS)
920#include <linux/init.h>
921#include <linux/proc_fs.h>
922
923static int
924asids_proc_info(char *buf, char **start, off_t fpos, int length, int *eof, void *data)
925{
926 int len=0;
927 struct task_struct *p;
928 read_lock(&tasklist_lock);
929 for_each_process(p) {
930 int pid = p->pid;
931 struct mm_struct *mm;
932 if (!pid) continue;
933 mm = p->mm;
934 if (mm) {
935 unsigned long asid, context;
936 context = mm->context;
937 asid = (context & 0xff);
938 len += sprintf(buf+len, "%5d : %02lx\n", pid, asid);
939 } else {
940 len += sprintf(buf+len, "%5d : (none)\n", pid);
941 }
942 }
943 read_unlock(&tasklist_lock);
944 *eof = 1;
945 return len;
946}
947
948static int __init register_proc_asids(void)
949{
950 create_proc_read_entry("asids", 0, NULL, asids_proc_info, NULL);
951 return 0;
952}
953
954__initcall(register_proc_asids);
955#endif
956
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