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/arch/parisc/kernel/process.c

https://bitbucket.org/evzijst/gittest
C | 396 lines | 197 code | 60 blank | 139 comment | 21 complexity | 1b6407a4bc125a16aaff8cb512fe2a04 MD5 | raw file
  1/*
  2 *    PARISC Architecture-dependent parts of process handling
  3 *    based on the work for i386
  4 *
  5 *    Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
  6 *    Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
  7 *    Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
  8 *    Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
  9 *    Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
 10 *    Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
 11 *    Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
 12 *    Copyright (C) 2000 Richard Hirst <rhirst with parisc-lixux.org>
 13 *    Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
 14 *    Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
 15 *    Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
 16 *    Copyright (C) 2001-2002 Helge Deller <deller at parisc-linux.org>
 17 *    Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
 18 *
 19 *
 20 *    This program is free software; you can redistribute it and/or modify
 21 *    it under the terms of the GNU General Public License as published by
 22 *    the Free Software Foundation; either version 2 of the License, or
 23 *    (at your option) any later version.
 24 *
 25 *    This program is distributed in the hope that it will be useful,
 26 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 27 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 28 *    GNU General Public License for more details.
 29 *
 30 *    You should have received a copy of the GNU General Public License
 31 *    along with this program; if not, write to the Free Software
 32 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 33 */
 34
 35#include <stdarg.h>
 36
 37#include <linux/elf.h>
 38#include <linux/errno.h>
 39#include <linux/kernel.h>
 40#include <linux/mm.h>
 41#include <linux/module.h>
 42#include <linux/personality.h>
 43#include <linux/ptrace.h>
 44#include <linux/sched.h>
 45#include <linux/stddef.h>
 46#include <linux/unistd.h>
 47#include <linux/kallsyms.h>
 48
 49#include <asm/io.h>
 50#include <asm/offsets.h>
 51#include <asm/pdc.h>
 52#include <asm/pdc_chassis.h>
 53#include <asm/pgalloc.h>
 54#include <asm/uaccess.h>
 55#include <asm/unwind.h>
 56
 57static int hlt_counter;
 58
 59/*
 60 * Power off function, if any
 61 */ 
 62void (*pm_power_off)(void);
 63
 64void disable_hlt(void)
 65{
 66	hlt_counter++;
 67}
 68
 69EXPORT_SYMBOL(disable_hlt);
 70
 71void enable_hlt(void)
 72{
 73	hlt_counter--;
 74}
 75
 76EXPORT_SYMBOL(enable_hlt);
 77
 78void default_idle(void)
 79{
 80	barrier();
 81}
 82
 83/*
 84 * The idle thread. There's no useful work to be
 85 * done, so just try to conserve power and have a
 86 * low exit latency (ie sit in a loop waiting for
 87 * somebody to say that they'd like to reschedule)
 88 */
 89void cpu_idle(void)
 90{
 91	/* endless idle loop with no priority at all */
 92	while (1) {
 93		while (!need_resched())
 94			barrier();
 95		schedule();
 96		check_pgt_cache();
 97	}
 98}
 99
100
101#ifdef __LP64__
102#define COMMAND_GLOBAL  0xfffffffffffe0030UL
103#else
104#define COMMAND_GLOBAL  0xfffe0030
105#endif
106
107#define CMD_RESET       5       /* reset any module */
108
109/*
110** The Wright Brothers and Gecko systems have a H/W problem
111** (Lasi...'nuf said) may cause a broadcast reset to lockup
112** the system. An HVERSION dependent PDC call was developed
113** to perform a "safe", platform specific broadcast reset instead
114** of kludging up all the code.
115**
116** Older machines which do not implement PDC_BROADCAST_RESET will
117** return (with an error) and the regular broadcast reset can be
118** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
119** the PDC call will not return (the system will be reset).
120*/
121void machine_restart(char *cmd)
122{
123#ifdef FASTBOOT_SELFTEST_SUPPORT
124	/*
125	 ** If user has modified the Firmware Selftest Bitmap,
126	 ** run the tests specified in the bitmap after the
127	 ** system is rebooted w/PDC_DO_RESET.
128	 **
129	 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
130	 **
131	 ** Using "directed resets" at each processor with the MEM_TOC
132	 ** vector cleared will also avoid running destructive
133	 ** memory self tests. (Not implemented yet)
134	 */
135	if (ftc_bitmap) {
136		pdc_do_firm_test_reset(ftc_bitmap);
137	}
138#endif
139	/* set up a new led state on systems shipped with a LED State panel */
140	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
141	
142	/* "Normal" system reset */
143	pdc_do_reset();
144
145	/* Nope...box should reset with just CMD_RESET now */
146	gsc_writel(CMD_RESET, COMMAND_GLOBAL);
147
148	/* Wait for RESET to lay us to rest. */
149	while (1) ;
150
151}
152
153EXPORT_SYMBOL(machine_restart);
154
155void machine_halt(void)
156{
157	/*
158	** The LED/ChassisCodes are updated by the led_halt()
159	** function, called by the reboot notifier chain.
160	*/
161}
162
163EXPORT_SYMBOL(machine_halt);
164
165
166/*
167 * This routine is called from sys_reboot to actually turn off the
168 * machine 
169 */
170void machine_power_off(void)
171{
172	/* If there is a registered power off handler, call it. */
173	if(pm_power_off)
174		pm_power_off();
175
176	/* Put the soft power button back under hardware control.
177	 * If the user had already pressed the power button, the
178	 * following call will immediately power off. */
179	pdc_soft_power_button(0);
180	
181	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
182		
183	/* It seems we have no way to power the system off via
184	 * software. The user has to press the button himself. */
185
186	printk(KERN_EMERG "System shut down completed.\n"
187	       KERN_EMERG "Please power this system off now.");
188}
189
190EXPORT_SYMBOL(machine_power_off);
191
192
193/*
194 * Create a kernel thread
195 */
196
197extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
198pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
199{
200
201	/*
202	 * FIXME: Once we are sure we don't need any debug here,
203	 *	  kernel_thread can become a #define.
204	 */
205
206	return __kernel_thread(fn, arg, flags);
207}
208EXPORT_SYMBOL(kernel_thread);
209
210/*
211 * Free current thread data structures etc..
212 */
213void exit_thread(void)
214{
215}
216
217void flush_thread(void)
218{
219	/* Only needs to handle fpu stuff or perf monitors.
220	** REVISIT: several arches implement a "lazy fpu state".
221	*/
222	set_fs(USER_DS);
223}
224
225void release_thread(struct task_struct *dead_task)
226{
227}
228
229/*
230 * Fill in the FPU structure for a core dump.
231 */
232
233int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
234{
235	if (regs == NULL)
236		return 0;
237
238	memcpy(r, regs->fr, sizeof *r);
239	return 1;
240}
241
242int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
243{
244	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
245	return 1;
246}
247
248/* Note that "fork()" is implemented in terms of clone, with
249   parameters (SIGCHLD, regs->gr[30], regs). */
250int
251sys_clone(unsigned long clone_flags, unsigned long usp,
252	  struct pt_regs *regs)
253{
254	int __user *user_tid = (int __user *)regs->gr[26];
255
256	/* usp must be word aligned.  This also prevents users from
257	 * passing in the value 1 (which is the signal for a special
258	 * return for a kernel thread) */
259	usp = ALIGN(usp, 4);
260
261	/* A zero value for usp means use the current stack */
262	if(usp == 0)
263		usp = regs->gr[30];
264
265	return do_fork(clone_flags, usp, regs, 0, user_tid, NULL);
266}
267
268int
269sys_vfork(struct pt_regs *regs)
270{
271	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
272}
273
274int
275copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
276	    unsigned long unused,	/* in ia64 this is "user_stack_size" */
277	    struct task_struct * p, struct pt_regs * pregs)
278{
279	struct pt_regs * cregs = &(p->thread.regs);
280	struct thread_info *ti = p->thread_info;
281	
282	/* We have to use void * instead of a function pointer, because
283	 * function pointers aren't a pointer to the function on 64-bit.
284	 * Make them const so the compiler knows they live in .text */
285	extern void * const ret_from_kernel_thread;
286	extern void * const child_return;
287#ifdef CONFIG_HPUX
288	extern void * const hpux_child_return;
289#endif
290
291	*cregs = *pregs;
292
293	/* Set the return value for the child.  Note that this is not
294           actually restored by the syscall exit path, but we put it
295           here for consistency in case of signals. */
296	cregs->gr[28] = 0; /* child */
297
298	/*
299	 * We need to differentiate between a user fork and a
300	 * kernel fork. We can't use user_mode, because the
301	 * the syscall path doesn't save iaoq. Right now
302	 * We rely on the fact that kernel_thread passes
303	 * in zero for usp.
304	 */
305	if (usp == 1) {
306		/* kernel thread */
307		cregs->ksp = (((unsigned long)(ti)) + THREAD_SZ_ALGN);
308		/* Must exit via ret_from_kernel_thread in order
309		 * to call schedule_tail()
310		 */
311		cregs->kpc = (unsigned long) &ret_from_kernel_thread;
312		/*
313		 * Copy function and argument to be called from
314		 * ret_from_kernel_thread.
315		 */
316#ifdef __LP64__
317		cregs->gr[27] = pregs->gr[27];
318#endif
319		cregs->gr[26] = pregs->gr[26];
320		cregs->gr[25] = pregs->gr[25];
321	} else {
322		/* user thread */
323		/*
324		 * Note that the fork wrappers are responsible
325		 * for setting gr[21].
326		 */
327
328		/* Use same stack depth as parent */
329		cregs->ksp = ((unsigned long)(ti))
330			+ (pregs->gr[21] & (THREAD_SIZE - 1));
331		cregs->gr[30] = usp;
332		if (p->personality == PER_HPUX) {
333#ifdef CONFIG_HPUX
334			cregs->kpc = (unsigned long) &hpux_child_return;
335#else
336			BUG();
337#endif
338		} else {
339			cregs->kpc = (unsigned long) &child_return;
340		}
341	}
342
343	return 0;
344}
345
346unsigned long thread_saved_pc(struct task_struct *t)
347{
348	return t->thread.regs.kpc;
349}
350
351/*
352 * sys_execve() executes a new program.
353 */
354
355asmlinkage int sys_execve(struct pt_regs *regs)
356{
357	int error;
358	char *filename;
359
360	filename = getname((const char __user *) regs->gr[26]);
361	error = PTR_ERR(filename);
362	if (IS_ERR(filename))
363		goto out;
364	error = do_execve(filename, (char __user **) regs->gr[25],
365		(char __user **) regs->gr[24], regs);
366	if (error == 0) {
367		task_lock(current);
368		current->ptrace &= ~PT_DTRACE;
369		task_unlock(current);
370	}
371	putname(filename);
372out:
373
374	return error;
375}
376
377unsigned long 
378get_wchan(struct task_struct *p)
379{
380	struct unwind_frame_info info;
381	unsigned long ip;
382	int count = 0;
383	/*
384	 * These bracket the sleeping functions..
385	 */
386
387	unwind_frame_init_from_blocked_task(&info, p);
388	do {
389		if (unwind_once(&info) < 0)
390			return 0;
391		ip = info.ip;
392		if (!in_sched_functions(ip))
393			return ip;
394	} while (count++ < 16);
395	return 0;
396}