xref: /openbmc/linux/arch/x86/kernel/apm_32.c (revision 93dc544c)
1 /* -*- linux-c -*-
2  * APM BIOS driver for Linux
3  * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
4  *
5  * Initial development of this driver was funded by NEC Australia P/L
6  *	and NEC Corporation
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the
10  * Free Software Foundation; either version 2, or (at your option) any
11  * later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * October 1995, Rik Faith (faith@cs.unc.edu):
19  *    Minor enhancements and updates (to the patch set) for 1.3.x
20  *    Documentation
21  * January 1996, Rik Faith (faith@cs.unc.edu):
22  *    Make /proc/apm easy to format (bump driver version)
23  * March 1996, Rik Faith (faith@cs.unc.edu):
24  *    Prohibit APM BIOS calls unless apm_enabled.
25  *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
26  * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
27  *    Version 1.0 and 1.1
28  * May 1996, Version 1.2
29  * Feb 1998, Version 1.3
30  * Feb 1998, Version 1.4
31  * Aug 1998, Version 1.5
32  * Sep 1998, Version 1.6
33  * Nov 1998, Version 1.7
34  * Jan 1999, Version 1.8
35  * Jan 1999, Version 1.9
36  * Oct 1999, Version 1.10
37  * Nov 1999, Version 1.11
38  * Jan 2000, Version 1.12
39  * Feb 2000, Version 1.13
40  * Nov 2000, Version 1.14
41  * Oct 2001, Version 1.15
42  * Jan 2002, Version 1.16
43  * Oct 2002, Version 1.16ac
44  *
45  * History:
46  *    0.6b: first version in official kernel, Linux 1.3.46
47  *    0.7: changed /proc/apm format, Linux 1.3.58
48  *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
49  *    0.9: only call bios if bios is present, Linux 1.3.72
50  *    1.0: use fixed device number, consolidate /proc/apm into this file,
51  *         Linux 1.3.85
52  *    1.1: support user-space standby and suspend, power off after system
53  *         halted, Linux 1.3.98
54  *    1.2: When resetting RTC after resume, take care so that the time
55  *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
56  *         <jtoth@princeton.edu>); improve interaction between
57  *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
58  *    1.2a:Simple change to stop mysterious bug reports with SMP also added
59  *	   levels to the printk calls. APM is not defined for SMP machines.
60  *         The new replacement for it is, but Linux doesn't yet support this.
61  *         Alan Cox Linux 2.1.55
62  *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
63  *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
64  *         Dean Gaudet <dgaudet@arctic.org>.
65  *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
66  *    1.5: Fix segment register reloading (in case of bad segments saved
67  *         across BIOS call).
68  *         Stephen Rothwell
69  *    1.6: Cope with complier/assembler differences.
70  *         Only try to turn off the first display device.
71  *         Fix OOPS at power off with no APM BIOS by Jan Echternach
72  *                   <echter@informatik.uni-rostock.de>
73  *         Stephen Rothwell
74  *    1.7: Modify driver's cached copy of the disabled/disengaged flags
75  *         to reflect current state of APM BIOS.
76  *         Chris Rankin <rankinc@bellsouth.net>
77  *         Reset interrupt 0 timer to 100Hz after suspend
78  *         Chad Miller <cmiller@surfsouth.com>
79  *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
80  *         Richard Gooch <rgooch@atnf.csiro.au>
81  *         Allow boot time disabling of APM
82  *         Make boot messages far less verbose by default
83  *         Make asm safer
84  *         Stephen Rothwell
85  *    1.8: Add CONFIG_APM_RTC_IS_GMT
86  *         Richard Gooch <rgooch@atnf.csiro.au>
87  *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
88  *         remove dependency on CONFIG_PROC_FS
89  *         Stephen Rothwell
90  *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
91  *         Try to cope with BIOS's that need to have all display
92  *         devices blanked and not just the first one.
93  *         Ross Paterson <ross@soi.city.ac.uk>
94  *         Fix segment limit setting it has always been wrong as
95  *         the segments needed to have byte granularity.
96  *         Mark a few things __init.
97  *         Add hack to allow power off of SMP systems by popular request.
98  *         Use CONFIG_SMP instead of __SMP__
99  *         Ignore BOUNCES for three seconds.
100  *         Stephen Rothwell
101  *   1.10: Fix for Thinkpad return code.
102  *         Merge 2.2 and 2.3 drivers.
103  *         Remove APM dependencies in arch/i386/kernel/process.c
104  *         Remove APM dependencies in drivers/char/sysrq.c
105  *         Reset time across standby.
106  *         Allow more inititialisation on SMP.
107  *         Remove CONFIG_APM_POWER_OFF and make it boot time
108  *         configurable (default on).
109  *         Make debug only a boot time parameter (remove APM_DEBUG).
110  *         Try to blank all devices on any error.
111  *   1.11: Remove APM dependencies in drivers/char/console.c
112  *         Check nr_running to detect if we are idle (from
113  *         Borislav Deianov <borislav@lix.polytechnique.fr>)
114  *         Fix for bioses that don't zero the top part of the
115  *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
116  *         (reported by Panos Katsaloulis <teras@writeme.com>).
117  *         Real mode power off patch (Walter Hofmann
118  *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
119  *   1.12: Remove CONFIG_SMP as the compiler will optimize
120  *         the code away anyway (smp_num_cpus == 1 in UP)
121  *         noted by Artur Skawina <skawina@geocities.com>.
122  *         Make power off under SMP work again.
123  *         Fix thinko with initial engaging of BIOS.
124  *         Make sure power off only happens on CPU 0
125  *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
126  *         Do error notification to user mode if BIOS calls fail.
127  *         Move entrypoint offset fix to ...boot/setup.S
128  *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
129  *         Remove smp-power-off. SMP users must now specify
130  *         "apm=power-off" on the kernel command line. Suggested
131  *         by Jim Avera <jima@hal.com>, modified by Alan Cox
132  *         <alan@lxorguk.ukuu.org.uk>.
133  *         Register the /proc/apm entry even on SMP so that
134  *         scripts that check for it before doing power off
135  *         work (Jim Avera <jima@hal.com>).
136  *   1.13: Changes for new pm_ interfaces (Andy Henroid
137  *         <andy_henroid@yahoo.com>).
138  *         Modularize the code.
139  *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
140  *         is now the way life works).
141  *         Fix thinko in suspend() (wrong return).
142  *         Notify drivers on critical suspend.
143  *         Make kapmd absorb more idle time (Pavel Machek <pavel@suse.cz>
144  *         modified by sfr).
145  *         Disable interrupts while we are suspended (Andy Henroid
146  *         <andy_henroid@yahoo.com> fixed by sfr).
147  *         Make power off work on SMP again (Tony Hoyle
148  *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
149  *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
150  *         interval is now configurable.
151  *   1.14: Make connection version persist across module unload/load.
152  *         Enable and engage power management earlier.
153  *         Disengage power management on module unload.
154  *         Changed to use the sysrq-register hack for registering the
155  *         power off function called by magic sysrq based upon discussions
156  *         in irc://irc.openprojects.net/#kernelnewbies
157  *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
158  *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
159  *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
160  *         Work around byte swap bug in one of the Vaio's BIOS's
161  *         (Marc Boucher <marc@mbsi.ca>).
162  *         Exposed the disable flag to dmi so that we can handle known
163  *         broken APM (Alan Cox <alan@redhat.com>).
164  *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165  *         calling it - instead idle. (Alan Cox <alan@redhat.com>)
166  *         If an APM idle fails log it and idle sensibly
167  *   1.15: Don't queue events to clients who open the device O_WRONLY.
168  *         Don't expect replies from clients who open the device O_RDONLY.
169  *         (Idea from Thomas Hood)
170  *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
171  *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
172  *         Notify listeners of standby or suspend events before notifying
173  *         drivers. Return EBUSY to ioctl() if suspend is rejected.
174  *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
175  *         Ignore first resume after we generate our own resume event
176  *         after a suspend (Thomas Hood)
177  *         Daemonize now gets rid of our controlling terminal (sfr).
178  *         CONFIG_APM_CPU_IDLE now just affects the default value of
179  *         idle_threshold (sfr).
180  *         Change name of kernel apm daemon (as it no longer idles) (sfr).
181  *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
182  *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
183  *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
184  *
185  * APM 1.1 Reference:
186  *
187  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
188  *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
189  *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
190  *
191  * [This document is available free from Intel by calling 800.628.8686 (fax
192  * 916.356.6100) or 800.548.4725; or via anonymous ftp from
193  * ftp://ftp.intel.com/pub/IAL/software_specs/apmv11.doc.  It is also
194  * available from Microsoft by calling 206.882.8080.]
195  *
196  * APM 1.2 Reference:
197  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
198  *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
199  *
200  * [This document is available from Microsoft at:
201  *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
202  */
203 
204 #include <linux/module.h>
205 
206 #include <linux/poll.h>
207 #include <linux/smp_lock.h>
208 #include <linux/types.h>
209 #include <linux/stddef.h>
210 #include <linux/timer.h>
211 #include <linux/fcntl.h>
212 #include <linux/slab.h>
213 #include <linux/stat.h>
214 #include <linux/proc_fs.h>
215 #include <linux/seq_file.h>
216 #include <linux/miscdevice.h>
217 #include <linux/apm_bios.h>
218 #include <linux/init.h>
219 #include <linux/time.h>
220 #include <linux/sched.h>
221 #include <linux/pm.h>
222 #include <linux/capability.h>
223 #include <linux/device.h>
224 #include <linux/kernel.h>
225 #include <linux/freezer.h>
226 #include <linux/smp.h>
227 #include <linux/dmi.h>
228 #include <linux/suspend.h>
229 #include <linux/kthread.h>
230 #include <linux/jiffies.h>
231 #include <linux/smp_lock.h>
232 
233 #include <asm/system.h>
234 #include <asm/uaccess.h>
235 #include <asm/desc.h>
236 #include <asm/i8253.h>
237 #include <asm/paravirt.h>
238 #include <asm/reboot.h>
239 
240 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
241 extern int (*console_blank_hook)(int);
242 #endif
243 
244 /*
245  * The apm_bios device is one of the misc char devices.
246  * This is its minor number.
247  */
248 #define	APM_MINOR_DEV	134
249 
250 /*
251  * See Documentation/Config.help for the configuration options.
252  *
253  * Various options can be changed at boot time as follows:
254  * (We allow underscores for compatibility with the modules code)
255  *	apm=on/off			enable/disable APM
256  *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
257  *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
258  *	    [no-]realmode[-_]power[-_]off	switch to real mode before
259  *	    					powering off
260  *	    [no-]debug			log some debugging messages
261  *	    [no-]power[-_]off		power off on shutdown
262  *	    [no-]smp			Use apm even on an SMP box
263  *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
264  *	    				bounces
265  *          idle[-_]threshold=<n>       System idle percentage above which to
266  *                                      make APM BIOS idle calls. Set it to
267  *                                      100 to disable.
268  *          idle[-_]period=<n>          Period (in 1/100s of a second) over
269  *                                      which the idle percentage is
270  *                                      calculated.
271  */
272 
273 /* KNOWN PROBLEM MACHINES:
274  *
275  * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
276  *                         [Confirmed by TI representative]
277  * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
278  *                    [Confirmed by BIOS disassembly]
279  *                    [This may work now ...]
280  * P: Toshiba 1950S: battery life information only gets updated after resume
281  * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
282  * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
283  * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
284  * 	Neale Banks <neale@lowendale.com.au> December 2000
285  *
286  * Legend: U = unusable with APM patches
287  *         P = partially usable with APM patches
288  */
289 
290 /*
291  * Define as 1 to make the driver always call the APM BIOS busy
292  * routine even if the clock was not reported as slowed by the
293  * idle routine.  Otherwise, define as 0.
294  */
295 #define ALWAYS_CALL_BUSY   1
296 
297 /*
298  * Define to make the APM BIOS calls zero all data segment registers (so
299  * that an incorrect BIOS implementation will cause a kernel panic if it
300  * tries to write to arbitrary memory).
301  */
302 #define APM_ZERO_SEGS
303 
304 #include "apm.h"
305 
306 /*
307  * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
308  * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
309  * David Chen <chen@ctpa04.mit.edu>
310  */
311 #undef INIT_TIMER_AFTER_SUSPEND
312 
313 #ifdef INIT_TIMER_AFTER_SUSPEND
314 #include <linux/timex.h>
315 #include <asm/io.h>
316 #include <linux/delay.h>
317 #endif
318 
319 /*
320  * Need to poll the APM BIOS every second
321  */
322 #define APM_CHECK_TIMEOUT	(HZ)
323 
324 /*
325  * Ignore suspend events for this amount of time after a resume
326  */
327 #define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
328 
329 /*
330  * Maximum number of events stored
331  */
332 #define APM_MAX_EVENTS		20
333 
334 /*
335  * The per-file APM data
336  */
337 struct apm_user {
338 	int		magic;
339 	struct apm_user *next;
340 	unsigned int	suser: 1;
341 	unsigned int	writer: 1;
342 	unsigned int	reader: 1;
343 	unsigned int	suspend_wait: 1;
344 	int		suspend_result;
345 	int		suspends_pending;
346 	int		standbys_pending;
347 	int		suspends_read;
348 	int		standbys_read;
349 	int		event_head;
350 	int		event_tail;
351 	apm_event_t	events[APM_MAX_EVENTS];
352 };
353 
354 /*
355  * The magic number in apm_user
356  */
357 #define APM_BIOS_MAGIC		0x4101
358 
359 /*
360  * idle percentage above which bios idle calls are done
361  */
362 #ifdef CONFIG_APM_CPU_IDLE
363 #define DEFAULT_IDLE_THRESHOLD	95
364 #else
365 #define DEFAULT_IDLE_THRESHOLD	100
366 #endif
367 #define DEFAULT_IDLE_PERIOD	(100 / 3)
368 
369 /*
370  * Local variables
371  */
372 static struct {
373 	unsigned long	offset;
374 	unsigned short	segment;
375 } apm_bios_entry;
376 static int clock_slowed;
377 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
378 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
379 static int set_pm_idle;
380 static int suspends_pending;
381 static int standbys_pending;
382 static int ignore_sys_suspend;
383 static int ignore_normal_resume;
384 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
385 
386 static int debug __read_mostly;
387 static int smp __read_mostly;
388 static int apm_disabled = -1;
389 #ifdef CONFIG_SMP
390 static int power_off;
391 #else
392 static int power_off = 1;
393 #endif
394 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
395 static int realmode_power_off = 1;
396 #else
397 static int realmode_power_off;
398 #endif
399 #ifdef CONFIG_APM_ALLOW_INTS
400 static int allow_ints = 1;
401 #else
402 static int allow_ints;
403 #endif
404 static int broken_psr;
405 
406 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
407 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
408 static struct apm_user *user_list;
409 static DEFINE_SPINLOCK(user_list_lock);
410 static const struct desc_struct	bad_bios_desc = { { { 0, 0x00409200 } } };
411 
412 static const char driver_version[] = "1.16ac";	/* no spaces */
413 
414 static struct task_struct *kapmd_task;
415 
416 /*
417  *	APM event names taken from the APM 1.2 specification. These are
418  *	the message codes that the BIOS uses to tell us about events
419  */
420 static const char * const apm_event_name[] = {
421 	"system standby",
422 	"system suspend",
423 	"normal resume",
424 	"critical resume",
425 	"low battery",
426 	"power status change",
427 	"update time",
428 	"critical suspend",
429 	"user standby",
430 	"user suspend",
431 	"system standby resume",
432 	"capabilities change"
433 };
434 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
435 
436 typedef struct lookup_t {
437 	int	key;
438 	char 	*msg;
439 } lookup_t;
440 
441 /*
442  *	The BIOS returns a set of standard error codes in AX when the
443  *	carry flag is set.
444  */
445 
446 static const lookup_t error_table[] = {
447 /* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
448 	{ APM_DISABLED,		"Power management disabled" },
449 	{ APM_CONNECTED,	"Real mode interface already connected" },
450 	{ APM_NOT_CONNECTED,	"Interface not connected" },
451 	{ APM_16_CONNECTED,	"16 bit interface already connected" },
452 /* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
453 	{ APM_32_CONNECTED,	"32 bit interface already connected" },
454 	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
455 	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
456 	{ APM_BAD_PARAM,	"Parameter out of range" },
457 	{ APM_NOT_ENGAGED,	"Interface not engaged" },
458 	{ APM_BAD_FUNCTION,     "Function not supported" },
459 	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
460 	{ APM_BAD_STATE,	"Unable to enter requested state" },
461 /* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
462 	{ APM_NO_ERROR,		"BIOS did not set a return code" },
463 	{ APM_NOT_PRESENT,	"No APM present" }
464 };
465 #define ERROR_COUNT	ARRAY_SIZE(error_table)
466 
467 /**
468  *	apm_error	-	display an APM error
469  *	@str: information string
470  *	@err: APM BIOS return code
471  *
472  *	Write a meaningful log entry to the kernel log in the event of
473  *	an APM error.
474  */
475 
476 static void apm_error(char *str, int err)
477 {
478 	int i;
479 
480 	for (i = 0; i < ERROR_COUNT; i++)
481 		if (error_table[i].key == err)
482 			break;
483 	if (i < ERROR_COUNT)
484 		printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
485 	else
486 		printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
487 		       str, err);
488 }
489 
490 /*
491  * Lock APM functionality to physical CPU 0
492  */
493 
494 #ifdef CONFIG_SMP
495 
496 static cpumask_t apm_save_cpus(void)
497 {
498 	cpumask_t x = current->cpus_allowed;
499 	/* Some bioses don't like being called from CPU != 0 */
500 	set_cpus_allowed(current, cpumask_of_cpu(0));
501 	BUG_ON(smp_processor_id() != 0);
502 	return x;
503 }
504 
505 static inline void apm_restore_cpus(cpumask_t mask)
506 {
507 	set_cpus_allowed(current, mask);
508 }
509 
510 #else
511 
512 /*
513  *	No CPU lockdown needed on a uniprocessor
514  */
515 
516 #define apm_save_cpus()		(current->cpus_allowed)
517 #define apm_restore_cpus(x)	(void)(x)
518 
519 #endif
520 
521 /*
522  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
523  * apm_info.allow_ints, we are being really paranoid here!  Not only
524  * are interrupts disabled, but all the segment registers (except SS)
525  * are saved and zeroed this means that if the BIOS tries to reference
526  * any data without explicitly loading the segment registers, the kernel
527  * will fault immediately rather than have some unforeseen circumstances
528  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
529  * this depends on CS referring to the same physical memory as DS so that
530  * DS can be zeroed before the call. Unfortunately, we can't do anything
531  * about the stack segment/pointer.  Also, we tell the compiler that
532  * everything could change.
533  *
534  * Also, we KNOW that for the non error case of apm_bios_call, there
535  * is no useful data returned in the low order 8 bits of eax.
536  */
537 
538 static inline unsigned long __apm_irq_save(void)
539 {
540 	unsigned long flags;
541 	local_save_flags(flags);
542 	if (apm_info.allow_ints) {
543 		if (irqs_disabled_flags(flags))
544 			local_irq_enable();
545 	} else
546 		local_irq_disable();
547 
548 	return flags;
549 }
550 
551 #define apm_irq_save(flags) \
552 	do { flags = __apm_irq_save(); } while (0)
553 
554 static inline void apm_irq_restore(unsigned long flags)
555 {
556 	if (irqs_disabled_flags(flags))
557 		local_irq_disable();
558 	else if (irqs_disabled())
559 		local_irq_enable();
560 }
561 
562 #ifdef APM_ZERO_SEGS
563 #	define APM_DECL_SEGS \
564 		unsigned int saved_fs; unsigned int saved_gs;
565 #	define APM_DO_SAVE_SEGS \
566 		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
567 #	define APM_DO_RESTORE_SEGS \
568 		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
569 #else
570 #	define APM_DECL_SEGS
571 #	define APM_DO_SAVE_SEGS
572 #	define APM_DO_RESTORE_SEGS
573 #endif
574 
575 /**
576  *	apm_bios_call	-	Make an APM BIOS 32bit call
577  *	@func: APM function to execute
578  *	@ebx_in: EBX register for call entry
579  *	@ecx_in: ECX register for call entry
580  *	@eax: EAX register return
581  *	@ebx: EBX register return
582  *	@ecx: ECX register return
583  *	@edx: EDX register return
584  *	@esi: ESI register return
585  *
586  *	Make an APM call using the 32bit protected mode interface. The
587  *	caller is responsible for knowing if APM BIOS is configured and
588  *	enabled. This call can disable interrupts for a long period of
589  *	time on some laptops.  The return value is in AH and the carry
590  *	flag is loaded into AL.  If there is an error, then the error
591  *	code is returned in AH (bits 8-15 of eax) and this function
592  *	returns non-zero.
593  */
594 
595 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
596 	u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
597 {
598 	APM_DECL_SEGS
599 	unsigned long		flags;
600 	cpumask_t		cpus;
601 	int			cpu;
602 	struct desc_struct	save_desc_40;
603 	struct desc_struct	*gdt;
604 
605 	cpus = apm_save_cpus();
606 
607 	cpu = get_cpu();
608 	gdt = get_cpu_gdt_table(cpu);
609 	save_desc_40 = gdt[0x40 / 8];
610 	gdt[0x40 / 8] = bad_bios_desc;
611 
612 	apm_irq_save(flags);
613 	APM_DO_SAVE_SEGS;
614 	apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
615 	APM_DO_RESTORE_SEGS;
616 	apm_irq_restore(flags);
617 	gdt[0x40 / 8] = save_desc_40;
618 	put_cpu();
619 	apm_restore_cpus(cpus);
620 
621 	return *eax & 0xff;
622 }
623 
624 /**
625  *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
626  *	@func: APM function to invoke
627  *	@ebx_in: EBX register value for BIOS call
628  *	@ecx_in: ECX register value for BIOS call
629  *	@eax: EAX register on return from the BIOS call
630  *
631  *	Make a BIOS call that returns one value only, or just status.
632  *	If there is an error, then the error code is returned in AH
633  *	(bits 8-15 of eax) and this function returns non-zero. This is
634  *	used for simpler BIOS operations. This call may hold interrupts
635  *	off for a long time on some laptops.
636  */
637 
638 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
639 {
640 	u8			error;
641 	APM_DECL_SEGS
642 	unsigned long		flags;
643 	cpumask_t		cpus;
644 	int			cpu;
645 	struct desc_struct	save_desc_40;
646 	struct desc_struct	*gdt;
647 
648 	cpus = apm_save_cpus();
649 
650 	cpu = get_cpu();
651 	gdt = get_cpu_gdt_table(cpu);
652 	save_desc_40 = gdt[0x40 / 8];
653 	gdt[0x40 / 8] = bad_bios_desc;
654 
655 	apm_irq_save(flags);
656 	APM_DO_SAVE_SEGS;
657 	error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
658 	APM_DO_RESTORE_SEGS;
659 	apm_irq_restore(flags);
660 	gdt[0x40 / 8] = save_desc_40;
661 	put_cpu();
662 	apm_restore_cpus(cpus);
663 	return error;
664 }
665 
666 /**
667  *	apm_driver_version	-	APM driver version
668  *	@val:	loaded with the APM version on return
669  *
670  *	Retrieve the APM version supported by the BIOS. This is only
671  *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
672  *	probably present.
673  *
674  *	On entry val should point to a value indicating the APM driver
675  *	version with the high byte being the major and the low byte the
676  *	minor number both in BCD
677  *
678  *	On return it will hold the BIOS revision supported in the
679  *	same format.
680  */
681 
682 static int apm_driver_version(u_short *val)
683 {
684 	u32 eax;
685 
686 	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
687 		return (eax >> 8) & 0xff;
688 	*val = eax;
689 	return APM_SUCCESS;
690 }
691 
692 /**
693  *	apm_get_event	-	get an APM event from the BIOS
694  *	@event: pointer to the event
695  *	@info: point to the event information
696  *
697  *	The APM BIOS provides a polled information for event
698  *	reporting. The BIOS expects to be polled at least every second
699  *	when events are pending. When a message is found the caller should
700  *	poll until no more messages are present.  However, this causes
701  *	problems on some laptops where a suspend event notification is
702  *	not cleared until it is acknowledged.
703  *
704  *	Additional information is returned in the info pointer, providing
705  *	that APM 1.2 is in use. If no messges are pending the value 0x80
706  *	is returned (No power management events pending).
707  */
708 
709 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
710 {
711 	u32 eax;
712 	u32 ebx;
713 	u32 ecx;
714 	u32 dummy;
715 
716 	if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
717 			  &dummy, &dummy))
718 		return (eax >> 8) & 0xff;
719 	*event = ebx;
720 	if (apm_info.connection_version < 0x0102)
721 		*info = ~0; /* indicate info not valid */
722 	else
723 		*info = ecx;
724 	return APM_SUCCESS;
725 }
726 
727 /**
728  *	set_power_state	-	set the power management state
729  *	@what: which items to transition
730  *	@state: state to transition to
731  *
732  *	Request an APM change of state for one or more system devices. The
733  *	processor state must be transitioned last of all. what holds the
734  *	class of device in the upper byte and the device number (0xFF for
735  *	all) for the object to be transitioned.
736  *
737  *	The state holds the state to transition to, which may in fact
738  *	be an acceptance of a BIOS requested state change.
739  */
740 
741 static int set_power_state(u_short what, u_short state)
742 {
743 	u32 eax;
744 
745 	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
746 		return (eax >> 8) & 0xff;
747 	return APM_SUCCESS;
748 }
749 
750 /**
751  *	set_system_power_state - set system wide power state
752  *	@state: which state to enter
753  *
754  *	Transition the entire system into a new APM power state.
755  */
756 
757 static int set_system_power_state(u_short state)
758 {
759 	return set_power_state(APM_DEVICE_ALL, state);
760 }
761 
762 /**
763  *	apm_do_idle	-	perform power saving
764  *
765  *	This function notifies the BIOS that the processor is (in the view
766  *	of the OS) idle. It returns -1 in the event that the BIOS refuses
767  *	to handle the idle request. On a success the function returns 1
768  *	if the BIOS did clock slowing or 0 otherwise.
769  */
770 
771 static int apm_do_idle(void)
772 {
773 	u32 eax;
774 	u8 ret = 0;
775 	int idled = 0;
776 	int polling;
777 
778 	polling = !!(current_thread_info()->status & TS_POLLING);
779 	if (polling) {
780 		current_thread_info()->status &= ~TS_POLLING;
781 		/*
782 		 * TS_POLLING-cleared state must be visible before we
783 		 * test NEED_RESCHED:
784 		 */
785 		smp_mb();
786 	}
787 	if (!need_resched()) {
788 		idled = 1;
789 		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
790 	}
791 	if (polling)
792 		current_thread_info()->status |= TS_POLLING;
793 
794 	if (!idled)
795 		return 0;
796 
797 	if (ret) {
798 		static unsigned long t;
799 
800 		/* This always fails on some SMP boards running UP kernels.
801 		 * Only report the failure the first 5 times.
802 		 */
803 		if (++t < 5) {
804 			printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
805 			       (eax >> 8) & 0xff);
806 			t = jiffies;
807 		}
808 		return -1;
809 	}
810 	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
811 	return clock_slowed;
812 }
813 
814 /**
815  *	apm_do_busy	-	inform the BIOS the CPU is busy
816  *
817  *	Request that the BIOS brings the CPU back to full performance.
818  */
819 
820 static void apm_do_busy(void)
821 {
822 	u32 dummy;
823 
824 	if (clock_slowed || ALWAYS_CALL_BUSY) {
825 		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
826 		clock_slowed = 0;
827 	}
828 }
829 
830 /*
831  * If no process has really been interested in
832  * the CPU for some time, we want to call BIOS
833  * power management - we probably want
834  * to conserve power.
835  */
836 #define IDLE_CALC_LIMIT	(HZ * 100)
837 #define IDLE_LEAKY_MAX	16
838 
839 static void (*original_pm_idle)(void) __read_mostly;
840 
841 /**
842  * apm_cpu_idle		-	cpu idling for APM capable Linux
843  *
844  * This is the idling function the kernel executes when APM is available. It
845  * tries to do BIOS powermanagement based on the average system idle time.
846  * Furthermore it calls the system default idle routine.
847  */
848 
849 static void apm_cpu_idle(void)
850 {
851 	static int use_apm_idle; /* = 0 */
852 	static unsigned int last_jiffies; /* = 0 */
853 	static unsigned int last_stime; /* = 0 */
854 
855 	int apm_idle_done = 0;
856 	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
857 	unsigned int bucket;
858 
859 recalc:
860 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
861 		use_apm_idle = 0;
862 		last_jiffies = jiffies;
863 		last_stime = current->stime;
864 	} else if (jiffies_since_last_check > idle_period) {
865 		unsigned int idle_percentage;
866 
867 		idle_percentage = current->stime - last_stime;
868 		idle_percentage *= 100;
869 		idle_percentage /= jiffies_since_last_check;
870 		use_apm_idle = (idle_percentage > idle_threshold);
871 		if (apm_info.forbid_idle)
872 			use_apm_idle = 0;
873 		last_jiffies = jiffies;
874 		last_stime = current->stime;
875 	}
876 
877 	bucket = IDLE_LEAKY_MAX;
878 
879 	while (!need_resched()) {
880 		if (use_apm_idle) {
881 			unsigned int t;
882 
883 			t = jiffies;
884 			switch (apm_do_idle()) {
885 			case 0:
886 				apm_idle_done = 1;
887 				if (t != jiffies) {
888 					if (bucket) {
889 						bucket = IDLE_LEAKY_MAX;
890 						continue;
891 					}
892 				} else if (bucket) {
893 					bucket--;
894 					continue;
895 				}
896 				break;
897 			case 1:
898 				apm_idle_done = 1;
899 				break;
900 			default: /* BIOS refused */
901 				break;
902 			}
903 		}
904 		if (original_pm_idle)
905 			original_pm_idle();
906 		else
907 			default_idle();
908 		local_irq_disable();
909 		jiffies_since_last_check = jiffies - last_jiffies;
910 		if (jiffies_since_last_check > idle_period)
911 			goto recalc;
912 	}
913 
914 	if (apm_idle_done)
915 		apm_do_busy();
916 
917 	local_irq_enable();
918 }
919 
920 /**
921  *	apm_power_off	-	ask the BIOS to power off
922  *
923  *	Handle the power off sequence. This is the one piece of code we
924  *	will execute even on SMP machines. In order to deal with BIOS
925  *	bugs we support real mode APM BIOS power off calls. We also make
926  *	the SMP call on CPU0 as some systems will only honour this call
927  *	on their first cpu.
928  */
929 
930 static void apm_power_off(void)
931 {
932 	unsigned char po_bios_call[] = {
933 		0xb8, 0x00, 0x10,	/* movw  $0x1000,ax  */
934 		0x8e, 0xd0,		/* movw  ax,ss       */
935 		0xbc, 0x00, 0xf0,	/* movw  $0xf000,sp  */
936 		0xb8, 0x07, 0x53,	/* movw  $0x5307,ax  */
937 		0xbb, 0x01, 0x00,	/* movw  $0x0001,bx  */
938 		0xb9, 0x03, 0x00,	/* movw  $0x0003,cx  */
939 		0xcd, 0x15		/* int   $0x15       */
940 	};
941 
942 	/* Some bioses don't like being called from CPU != 0 */
943 	if (apm_info.realmode_power_off) {
944 		(void)apm_save_cpus();
945 		machine_real_restart(po_bios_call, sizeof(po_bios_call));
946 	} else {
947 		(void)set_system_power_state(APM_STATE_OFF);
948 	}
949 }
950 
951 #ifdef CONFIG_APM_DO_ENABLE
952 
953 /**
954  *	apm_enable_power_management - enable BIOS APM power management
955  *	@enable: enable yes/no
956  *
957  *	Enable or disable the APM BIOS power services.
958  */
959 
960 static int apm_enable_power_management(int enable)
961 {
962 	u32 eax;
963 
964 	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
965 		return APM_NOT_ENGAGED;
966 	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
967 				 enable, &eax))
968 		return (eax >> 8) & 0xff;
969 	if (enable)
970 		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
971 	else
972 		apm_info.bios.flags |= APM_BIOS_DISABLED;
973 	return APM_SUCCESS;
974 }
975 #endif
976 
977 /**
978  *	apm_get_power_status	-	get current power state
979  *	@status: returned status
980  *	@bat: battery info
981  *	@life: estimated life
982  *
983  *	Obtain the current power status from the APM BIOS. We return a
984  *	status which gives the rough battery status, and current power
985  *	source. The bat value returned give an estimate as a percentage
986  *	of life and a status value for the battery. The estimated life
987  *	if reported is a lifetime in secodnds/minutes at current powwer
988  *	consumption.
989  */
990 
991 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
992 {
993 	u32 eax;
994 	u32 ebx;
995 	u32 ecx;
996 	u32 edx;
997 	u32 dummy;
998 
999 	if (apm_info.get_power_status_broken)
1000 		return APM_32_UNSUPPORTED;
1001 	if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
1002 			  &eax, &ebx, &ecx, &edx, &dummy))
1003 		return (eax >> 8) & 0xff;
1004 	*status = ebx;
1005 	*bat = ecx;
1006 	if (apm_info.get_power_status_swabinminutes) {
1007 		*life = swab16((u16)edx);
1008 		*life |= 0x8000;
1009 	} else
1010 		*life = edx;
1011 	return APM_SUCCESS;
1012 }
1013 
1014 #if 0
1015 static int apm_get_battery_status(u_short which, u_short *status,
1016 				  u_short *bat, u_short *life, u_short *nbat)
1017 {
1018 	u32 eax;
1019 	u32 ebx;
1020 	u32 ecx;
1021 	u32 edx;
1022 	u32 esi;
1023 
1024 	if (apm_info.connection_version < 0x0102) {
1025 		/* pretend we only have one battery. */
1026 		if (which != 1)
1027 			return APM_BAD_DEVICE;
1028 		*nbat = 1;
1029 		return apm_get_power_status(status, bat, life);
1030 	}
1031 
1032 	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1033 			  &ebx, &ecx, &edx, &esi))
1034 		return (eax >> 8) & 0xff;
1035 	*status = ebx;
1036 	*bat = ecx;
1037 	*life = edx;
1038 	*nbat = esi;
1039 	return APM_SUCCESS;
1040 }
1041 #endif
1042 
1043 /**
1044  *	apm_engage_power_management	-	enable PM on a device
1045  *	@device: identity of device
1046  *	@enable: on/off
1047  *
1048  *	Activate or deactive power management on either a specific device
1049  *	or the entire system (%APM_DEVICE_ALL).
1050  */
1051 
1052 static int apm_engage_power_management(u_short device, int enable)
1053 {
1054 	u32 eax;
1055 
1056 	if ((enable == 0) && (device == APM_DEVICE_ALL)
1057 	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1058 		return APM_DISABLED;
1059 	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1060 		return (eax >> 8) & 0xff;
1061 	if (device == APM_DEVICE_ALL) {
1062 		if (enable)
1063 			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1064 		else
1065 			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1066 	}
1067 	return APM_SUCCESS;
1068 }
1069 
1070 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1071 
1072 /**
1073  *	apm_console_blank	-	blank the display
1074  *	@blank: on/off
1075  *
1076  *	Attempt to blank the console, firstly by blanking just video device
1077  *	zero, and if that fails (some BIOSes don't support it) then it blanks
1078  *	all video devices. Typically the BIOS will do laptop backlight and
1079  *	monitor powerdown for us.
1080  */
1081 
1082 static int apm_console_blank(int blank)
1083 {
1084 	int error = APM_NOT_ENGAGED; /* silence gcc */
1085 	int i;
1086 	u_short state;
1087 	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1088 
1089 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1090 
1091 	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1092 		error = set_power_state(dev[i], state);
1093 
1094 		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1095 			return 1;
1096 
1097 		if (error == APM_NOT_ENGAGED)
1098 			break;
1099 	}
1100 
1101 	if (error == APM_NOT_ENGAGED) {
1102 		static int tried;
1103 		int eng_error;
1104 		if (tried++ == 0) {
1105 			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1106 			if (eng_error) {
1107 				apm_error("set display", error);
1108 				apm_error("engage interface", eng_error);
1109 				return 0;
1110 			} else
1111 				return apm_console_blank(blank);
1112 		}
1113 	}
1114 	apm_error("set display", error);
1115 	return 0;
1116 }
1117 #endif
1118 
1119 static int queue_empty(struct apm_user *as)
1120 {
1121 	return as->event_head == as->event_tail;
1122 }
1123 
1124 static apm_event_t get_queued_event(struct apm_user *as)
1125 {
1126 	if (++as->event_tail >= APM_MAX_EVENTS)
1127 		as->event_tail = 0;
1128 	return as->events[as->event_tail];
1129 }
1130 
1131 static void queue_event(apm_event_t event, struct apm_user *sender)
1132 {
1133 	struct apm_user *as;
1134 
1135 	spin_lock(&user_list_lock);
1136 	if (user_list == NULL)
1137 		goto out;
1138 	for (as = user_list; as != NULL; as = as->next) {
1139 		if ((as == sender) || (!as->reader))
1140 			continue;
1141 		if (++as->event_head >= APM_MAX_EVENTS)
1142 			as->event_head = 0;
1143 
1144 		if (as->event_head == as->event_tail) {
1145 			static int notified;
1146 
1147 			if (notified++ == 0)
1148 			    printk(KERN_ERR "apm: an event queue overflowed\n");
1149 			if (++as->event_tail >= APM_MAX_EVENTS)
1150 				as->event_tail = 0;
1151 		}
1152 		as->events[as->event_head] = event;
1153 		if (!as->suser || !as->writer)
1154 			continue;
1155 		switch (event) {
1156 		case APM_SYS_SUSPEND:
1157 		case APM_USER_SUSPEND:
1158 			as->suspends_pending++;
1159 			suspends_pending++;
1160 			break;
1161 
1162 		case APM_SYS_STANDBY:
1163 		case APM_USER_STANDBY:
1164 			as->standbys_pending++;
1165 			standbys_pending++;
1166 			break;
1167 		}
1168 	}
1169 	wake_up_interruptible(&apm_waitqueue);
1170 out:
1171 	spin_unlock(&user_list_lock);
1172 }
1173 
1174 static void reinit_timer(void)
1175 {
1176 #ifdef INIT_TIMER_AFTER_SUSPEND
1177 	unsigned long flags;
1178 
1179 	spin_lock_irqsave(&i8253_lock, flags);
1180 	/* set the clock to HZ */
1181 	outb_pit(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1182 	udelay(10);
1183 	outb_pit(LATCH & 0xff, PIT_CH0);	/* LSB */
1184 	udelay(10);
1185 	outb_pit(LATCH >> 8, PIT_CH0);	/* MSB */
1186 	udelay(10);
1187 	spin_unlock_irqrestore(&i8253_lock, flags);
1188 #endif
1189 }
1190 
1191 static int suspend(int vetoable)
1192 {
1193 	int err;
1194 	struct apm_user	*as;
1195 
1196 	device_suspend(PMSG_SUSPEND);
1197 	local_irq_disable();
1198 	device_power_down(PMSG_SUSPEND);
1199 
1200 	local_irq_enable();
1201 
1202 	save_processor_state();
1203 	err = set_system_power_state(APM_STATE_SUSPEND);
1204 	ignore_normal_resume = 1;
1205 	restore_processor_state();
1206 
1207 	local_irq_disable();
1208 	reinit_timer();
1209 
1210 	if (err == APM_NO_ERROR)
1211 		err = APM_SUCCESS;
1212 	if (err != APM_SUCCESS)
1213 		apm_error("suspend", err);
1214 	err = (err == APM_SUCCESS) ? 0 : -EIO;
1215 	device_power_up(PMSG_RESUME);
1216 	local_irq_enable();
1217 	device_resume(PMSG_RESUME);
1218 	queue_event(APM_NORMAL_RESUME, NULL);
1219 	spin_lock(&user_list_lock);
1220 	for (as = user_list; as != NULL; as = as->next) {
1221 		as->suspend_wait = 0;
1222 		as->suspend_result = err;
1223 	}
1224 	spin_unlock(&user_list_lock);
1225 	wake_up_interruptible(&apm_suspend_waitqueue);
1226 	return err;
1227 }
1228 
1229 static void standby(void)
1230 {
1231 	int err;
1232 
1233 	local_irq_disable();
1234 	device_power_down(PMSG_SUSPEND);
1235 	local_irq_enable();
1236 
1237 	err = set_system_power_state(APM_STATE_STANDBY);
1238 	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1239 		apm_error("standby", err);
1240 
1241 	local_irq_disable();
1242 	device_power_up(PMSG_RESUME);
1243 	local_irq_enable();
1244 }
1245 
1246 static apm_event_t get_event(void)
1247 {
1248 	int error;
1249 	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1250 	apm_eventinfo_t	info;
1251 
1252 	static int notified;
1253 
1254 	/* we don't use the eventinfo */
1255 	error = apm_get_event(&event, &info);
1256 	if (error == APM_SUCCESS)
1257 		return event;
1258 
1259 	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1260 		apm_error("get_event", error);
1261 
1262 	return 0;
1263 }
1264 
1265 static void check_events(void)
1266 {
1267 	apm_event_t event;
1268 	static unsigned long last_resume;
1269 	static int ignore_bounce;
1270 
1271 	while ((event = get_event()) != 0) {
1272 		if (debug) {
1273 			if (event <= NR_APM_EVENT_NAME)
1274 				printk(KERN_DEBUG "apm: received %s notify\n",
1275 				       apm_event_name[event - 1]);
1276 			else
1277 				printk(KERN_DEBUG "apm: received unknown "
1278 				       "event 0x%02x\n", event);
1279 		}
1280 		if (ignore_bounce
1281 		    && (time_after(jiffies, last_resume + bounce_interval)))
1282 			ignore_bounce = 0;
1283 
1284 		switch (event) {
1285 		case APM_SYS_STANDBY:
1286 		case APM_USER_STANDBY:
1287 			queue_event(event, NULL);
1288 			if (standbys_pending <= 0)
1289 				standby();
1290 			break;
1291 
1292 		case APM_USER_SUSPEND:
1293 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1294 			if (apm_info.connection_version > 0x100)
1295 				set_system_power_state(APM_STATE_REJECT);
1296 			break;
1297 #endif
1298 		case APM_SYS_SUSPEND:
1299 			if (ignore_bounce) {
1300 				if (apm_info.connection_version > 0x100)
1301 					set_system_power_state(APM_STATE_REJECT);
1302 				break;
1303 			}
1304 			/*
1305 			 * If we are already processing a SUSPEND,
1306 			 * then further SUSPEND events from the BIOS
1307 			 * will be ignored.  We also return here to
1308 			 * cope with the fact that the Thinkpads keep
1309 			 * sending a SUSPEND event until something else
1310 			 * happens!
1311 			 */
1312 			if (ignore_sys_suspend)
1313 				return;
1314 			ignore_sys_suspend = 1;
1315 			queue_event(event, NULL);
1316 			if (suspends_pending <= 0)
1317 				(void) suspend(1);
1318 			break;
1319 
1320 		case APM_NORMAL_RESUME:
1321 		case APM_CRITICAL_RESUME:
1322 		case APM_STANDBY_RESUME:
1323 			ignore_sys_suspend = 0;
1324 			last_resume = jiffies;
1325 			ignore_bounce = 1;
1326 			if ((event != APM_NORMAL_RESUME)
1327 			    || (ignore_normal_resume == 0)) {
1328 				device_resume(PMSG_RESUME);
1329 				queue_event(event, NULL);
1330 			}
1331 			ignore_normal_resume = 0;
1332 			break;
1333 
1334 		case APM_CAPABILITY_CHANGE:
1335 		case APM_LOW_BATTERY:
1336 		case APM_POWER_STATUS_CHANGE:
1337 			queue_event(event, NULL);
1338 			/* If needed, notify drivers here */
1339 			break;
1340 
1341 		case APM_UPDATE_TIME:
1342 			break;
1343 
1344 		case APM_CRITICAL_SUSPEND:
1345 			/*
1346 			 * We are not allowed to reject a critical suspend.
1347 			 */
1348 			(void)suspend(0);
1349 			break;
1350 		}
1351 	}
1352 }
1353 
1354 static void apm_event_handler(void)
1355 {
1356 	static int pending_count = 4;
1357 	int err;
1358 
1359 	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1360 		if ((apm_info.connection_version > 0x100) &&
1361 		    (pending_count-- <= 0)) {
1362 			pending_count = 4;
1363 			if (debug)
1364 				printk(KERN_DEBUG "apm: setting state busy\n");
1365 			err = set_system_power_state(APM_STATE_BUSY);
1366 			if (err)
1367 				apm_error("busy", err);
1368 		}
1369 	} else
1370 		pending_count = 4;
1371 	check_events();
1372 }
1373 
1374 /*
1375  * This is the APM thread main loop.
1376  */
1377 
1378 static void apm_mainloop(void)
1379 {
1380 	DECLARE_WAITQUEUE(wait, current);
1381 
1382 	add_wait_queue(&apm_waitqueue, &wait);
1383 	set_current_state(TASK_INTERRUPTIBLE);
1384 	for (;;) {
1385 		schedule_timeout(APM_CHECK_TIMEOUT);
1386 		if (kthread_should_stop())
1387 			break;
1388 		/*
1389 		 * Ok, check all events, check for idle (and mark us sleeping
1390 		 * so as not to count towards the load average)..
1391 		 */
1392 		set_current_state(TASK_INTERRUPTIBLE);
1393 		apm_event_handler();
1394 	}
1395 	remove_wait_queue(&apm_waitqueue, &wait);
1396 }
1397 
1398 static int check_apm_user(struct apm_user *as, const char *func)
1399 {
1400 	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1401 		printk(KERN_ERR "apm: %s passed bad filp\n", func);
1402 		return 1;
1403 	}
1404 	return 0;
1405 }
1406 
1407 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1408 {
1409 	struct apm_user *as;
1410 	int i;
1411 	apm_event_t event;
1412 
1413 	as = fp->private_data;
1414 	if (check_apm_user(as, "read"))
1415 		return -EIO;
1416 	if ((int)count < sizeof(apm_event_t))
1417 		return -EINVAL;
1418 	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1419 		return -EAGAIN;
1420 	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1421 	i = count;
1422 	while ((i >= sizeof(event)) && !queue_empty(as)) {
1423 		event = get_queued_event(as);
1424 		if (copy_to_user(buf, &event, sizeof(event))) {
1425 			if (i < count)
1426 				break;
1427 			return -EFAULT;
1428 		}
1429 		switch (event) {
1430 		case APM_SYS_SUSPEND:
1431 		case APM_USER_SUSPEND:
1432 			as->suspends_read++;
1433 			break;
1434 
1435 		case APM_SYS_STANDBY:
1436 		case APM_USER_STANDBY:
1437 			as->standbys_read++;
1438 			break;
1439 		}
1440 		buf += sizeof(event);
1441 		i -= sizeof(event);
1442 	}
1443 	if (i < count)
1444 		return count - i;
1445 	if (signal_pending(current))
1446 		return -ERESTARTSYS;
1447 	return 0;
1448 }
1449 
1450 static unsigned int do_poll(struct file *fp, poll_table *wait)
1451 {
1452 	struct apm_user *as;
1453 
1454 	as = fp->private_data;
1455 	if (check_apm_user(as, "poll"))
1456 		return 0;
1457 	poll_wait(fp, &apm_waitqueue, wait);
1458 	if (!queue_empty(as))
1459 		return POLLIN | POLLRDNORM;
1460 	return 0;
1461 }
1462 
1463 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1464 {
1465 	struct apm_user *as;
1466 	int ret;
1467 
1468 	as = filp->private_data;
1469 	if (check_apm_user(as, "ioctl"))
1470 		return -EIO;
1471 	if (!as->suser || !as->writer)
1472 		return -EPERM;
1473 	switch (cmd) {
1474 	case APM_IOC_STANDBY:
1475 		lock_kernel();
1476 		if (as->standbys_read > 0) {
1477 			as->standbys_read--;
1478 			as->standbys_pending--;
1479 			standbys_pending--;
1480 		} else
1481 			queue_event(APM_USER_STANDBY, as);
1482 		if (standbys_pending <= 0)
1483 			standby();
1484 		unlock_kernel();
1485 		break;
1486 	case APM_IOC_SUSPEND:
1487 		lock_kernel();
1488 		if (as->suspends_read > 0) {
1489 			as->suspends_read--;
1490 			as->suspends_pending--;
1491 			suspends_pending--;
1492 		} else
1493 			queue_event(APM_USER_SUSPEND, as);
1494 		if (suspends_pending <= 0) {
1495 			ret = suspend(1);
1496 		} else {
1497 			as->suspend_wait = 1;
1498 			wait_event_interruptible(apm_suspend_waitqueue,
1499 					as->suspend_wait == 0);
1500 			ret = as->suspend_result;
1501 		}
1502 		unlock_kernel();
1503 		return ret;
1504 	default:
1505 		return -ENOTTY;
1506 	}
1507 	return 0;
1508 }
1509 
1510 static int do_release(struct inode *inode, struct file *filp)
1511 {
1512 	struct apm_user *as;
1513 
1514 	as = filp->private_data;
1515 	if (check_apm_user(as, "release"))
1516 		return 0;
1517 	filp->private_data = NULL;
1518 	if (as->standbys_pending > 0) {
1519 		standbys_pending -= as->standbys_pending;
1520 		if (standbys_pending <= 0)
1521 			standby();
1522 	}
1523 	if (as->suspends_pending > 0) {
1524 		suspends_pending -= as->suspends_pending;
1525 		if (suspends_pending <= 0)
1526 			(void) suspend(1);
1527 	}
1528 	spin_lock(&user_list_lock);
1529 	if (user_list == as)
1530 		user_list = as->next;
1531 	else {
1532 		struct apm_user *as1;
1533 
1534 		for (as1 = user_list;
1535 		     (as1 != NULL) && (as1->next != as);
1536 		     as1 = as1->next)
1537 			;
1538 		if (as1 == NULL)
1539 			printk(KERN_ERR "apm: filp not in user list\n");
1540 		else
1541 			as1->next = as->next;
1542 	}
1543 	spin_unlock(&user_list_lock);
1544 	kfree(as);
1545 	return 0;
1546 }
1547 
1548 static int do_open(struct inode *inode, struct file *filp)
1549 {
1550 	struct apm_user *as;
1551 
1552 	lock_kernel();
1553 	as = kmalloc(sizeof(*as), GFP_KERNEL);
1554 	if (as == NULL) {
1555 		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1556 		       sizeof(*as));
1557 		       unlock_kernel();
1558 		return -ENOMEM;
1559 	}
1560 	as->magic = APM_BIOS_MAGIC;
1561 	as->event_tail = as->event_head = 0;
1562 	as->suspends_pending = as->standbys_pending = 0;
1563 	as->suspends_read = as->standbys_read = 0;
1564 	/*
1565 	 * XXX - this is a tiny bit broken, when we consider BSD
1566 	 * process accounting. If the device is opened by root, we
1567 	 * instantly flag that we used superuser privs. Who knows,
1568 	 * we might close the device immediately without doing a
1569 	 * privileged operation -- cevans
1570 	 */
1571 	as->suser = capable(CAP_SYS_ADMIN);
1572 	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1573 	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1574 	spin_lock(&user_list_lock);
1575 	as->next = user_list;
1576 	user_list = as;
1577 	spin_unlock(&user_list_lock);
1578 	filp->private_data = as;
1579 	unlock_kernel();
1580 	return 0;
1581 }
1582 
1583 static int proc_apm_show(struct seq_file *m, void *v)
1584 {
1585 	unsigned short	bx;
1586 	unsigned short	cx;
1587 	unsigned short	dx;
1588 	int		error;
1589 	unsigned short  ac_line_status = 0xff;
1590 	unsigned short  battery_status = 0xff;
1591 	unsigned short  battery_flag   = 0xff;
1592 	int		percentage     = -1;
1593 	int             time_units     = -1;
1594 	char            *units         = "?";
1595 
1596 	if ((num_online_cpus() == 1) &&
1597 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1598 		ac_line_status = (bx >> 8) & 0xff;
1599 		battery_status = bx & 0xff;
1600 		if ((cx & 0xff) != 0xff)
1601 			percentage = cx & 0xff;
1602 
1603 		if (apm_info.connection_version > 0x100) {
1604 			battery_flag = (cx >> 8) & 0xff;
1605 			if (dx != 0xffff) {
1606 				units = (dx & 0x8000) ? "min" : "sec";
1607 				time_units = dx & 0x7fff;
1608 			}
1609 		}
1610 	}
1611 	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1612 	   from the Get Power Status (0x0a) call unless otherwise noted.
1613 
1614 	   0) Linux driver version (this will change if format changes)
1615 	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1616 	   2) APM flags from APM Installation Check (0x00):
1617 	      bit 0: APM_16_BIT_SUPPORT
1618 	      bit 1: APM_32_BIT_SUPPORT
1619 	      bit 2: APM_IDLE_SLOWS_CLOCK
1620 	      bit 3: APM_BIOS_DISABLED
1621 	      bit 4: APM_BIOS_DISENGAGED
1622 	   3) AC line status
1623 	      0x00: Off-line
1624 	      0x01: On-line
1625 	      0x02: On backup power (BIOS >= 1.1 only)
1626 	      0xff: Unknown
1627 	   4) Battery status
1628 	      0x00: High
1629 	      0x01: Low
1630 	      0x02: Critical
1631 	      0x03: Charging
1632 	      0x04: Selected battery not present (BIOS >= 1.2 only)
1633 	      0xff: Unknown
1634 	   5) Battery flag
1635 	      bit 0: High
1636 	      bit 1: Low
1637 	      bit 2: Critical
1638 	      bit 3: Charging
1639 	      bit 7: No system battery
1640 	      0xff: Unknown
1641 	   6) Remaining battery life (percentage of charge):
1642 	      0-100: valid
1643 	      -1: Unknown
1644 	   7) Remaining battery life (time units):
1645 	      Number of remaining minutes or seconds
1646 	      -1: Unknown
1647 	   8) min = minutes; sec = seconds */
1648 
1649 	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1650 		   driver_version,
1651 		   (apm_info.bios.version >> 8) & 0xff,
1652 		   apm_info.bios.version & 0xff,
1653 		   apm_info.bios.flags,
1654 		   ac_line_status,
1655 		   battery_status,
1656 		   battery_flag,
1657 		   percentage,
1658 		   time_units,
1659 		   units);
1660 	return 0;
1661 }
1662 
1663 static int proc_apm_open(struct inode *inode, struct file *file)
1664 {
1665 	return single_open(file, proc_apm_show, NULL);
1666 }
1667 
1668 static const struct file_operations apm_file_ops = {
1669 	.owner		= THIS_MODULE,
1670 	.open		= proc_apm_open,
1671 	.read		= seq_read,
1672 	.llseek		= seq_lseek,
1673 	.release	= single_release,
1674 };
1675 
1676 static int apm(void *unused)
1677 {
1678 	unsigned short	bx;
1679 	unsigned short	cx;
1680 	unsigned short	dx;
1681 	int		error;
1682 	char 		*power_stat;
1683 	char 		*bat_stat;
1684 
1685 #ifdef CONFIG_SMP
1686 	/* 2002/08/01 - WT
1687 	 * This is to avoid random crashes at boot time during initialization
1688 	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1689 	 * Some bioses don't like being called from CPU != 0.
1690 	 * Method suggested by Ingo Molnar.
1691 	 */
1692 	set_cpus_allowed(current, cpumask_of_cpu(0));
1693 	BUG_ON(smp_processor_id() != 0);
1694 #endif
1695 
1696 	if (apm_info.connection_version == 0) {
1697 		apm_info.connection_version = apm_info.bios.version;
1698 		if (apm_info.connection_version > 0x100) {
1699 			/*
1700 			 * We only support BIOSs up to version 1.2
1701 			 */
1702 			if (apm_info.connection_version > 0x0102)
1703 				apm_info.connection_version = 0x0102;
1704 			error = apm_driver_version(&apm_info.connection_version);
1705 			if (error != APM_SUCCESS) {
1706 				apm_error("driver version", error);
1707 				/* Fall back to an APM 1.0 connection. */
1708 				apm_info.connection_version = 0x100;
1709 			}
1710 		}
1711 	}
1712 
1713 	if (debug)
1714 		printk(KERN_INFO "apm: Connection version %d.%d\n",
1715 			(apm_info.connection_version >> 8) & 0xff,
1716 			apm_info.connection_version & 0xff);
1717 
1718 #ifdef CONFIG_APM_DO_ENABLE
1719 	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1720 		/*
1721 		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1722 		 * is booted with PM disabled but not in the docking station.
1723 		 * Unfortunate ...
1724 		 */
1725 		error = apm_enable_power_management(1);
1726 		if (error) {
1727 			apm_error("enable power management", error);
1728 			return -1;
1729 		}
1730 	}
1731 #endif
1732 
1733 	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1734 	    && (apm_info.connection_version > 0x0100)) {
1735 		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1736 		if (error) {
1737 			apm_error("engage power management", error);
1738 			return -1;
1739 		}
1740 	}
1741 
1742 	if (debug && (num_online_cpus() == 1 || smp)) {
1743 		error = apm_get_power_status(&bx, &cx, &dx);
1744 		if (error)
1745 			printk(KERN_INFO "apm: power status not available\n");
1746 		else {
1747 			switch ((bx >> 8) & 0xff) {
1748 			case 0:
1749 				power_stat = "off line";
1750 				break;
1751 			case 1:
1752 				power_stat = "on line";
1753 				break;
1754 			case 2:
1755 				power_stat = "on backup power";
1756 				break;
1757 			default:
1758 				power_stat = "unknown";
1759 				break;
1760 			}
1761 			switch (bx & 0xff) {
1762 			case 0:
1763 				bat_stat = "high";
1764 				break;
1765 			case 1:
1766 				bat_stat = "low";
1767 				break;
1768 			case 2:
1769 				bat_stat = "critical";
1770 				break;
1771 			case 3:
1772 				bat_stat = "charging";
1773 				break;
1774 			default:
1775 				bat_stat = "unknown";
1776 				break;
1777 			}
1778 			printk(KERN_INFO
1779 			       "apm: AC %s, battery status %s, battery life ",
1780 			       power_stat, bat_stat);
1781 			if ((cx & 0xff) == 0xff)
1782 				printk("unknown\n");
1783 			else
1784 				printk("%d%%\n", cx & 0xff);
1785 			if (apm_info.connection_version > 0x100) {
1786 				printk(KERN_INFO
1787 				       "apm: battery flag 0x%02x, battery life ",
1788 				       (cx >> 8) & 0xff);
1789 				if (dx == 0xffff)
1790 					printk("unknown\n");
1791 				else
1792 					printk("%d %s\n", dx & 0x7fff,
1793 					       (dx & 0x8000) ?
1794 					       "minutes" : "seconds");
1795 			}
1796 		}
1797 	}
1798 
1799 	/* Install our power off handler.. */
1800 	if (power_off)
1801 		pm_power_off = apm_power_off;
1802 
1803 	if (num_online_cpus() == 1 || smp) {
1804 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1805 		console_blank_hook = apm_console_blank;
1806 #endif
1807 		apm_mainloop();
1808 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1809 		console_blank_hook = NULL;
1810 #endif
1811 	}
1812 
1813 	return 0;
1814 }
1815 
1816 #ifndef MODULE
1817 static int __init apm_setup(char *str)
1818 {
1819 	int invert;
1820 
1821 	while ((str != NULL) && (*str != '\0')) {
1822 		if (strncmp(str, "off", 3) == 0)
1823 			apm_disabled = 1;
1824 		if (strncmp(str, "on", 2) == 0)
1825 			apm_disabled = 0;
1826 		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1827 		    (strncmp(str, "bounce_interval=", 16) == 0))
1828 			bounce_interval = simple_strtol(str + 16, NULL, 0);
1829 		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1830 		    (strncmp(str, "idle_threshold=", 15) == 0))
1831 			idle_threshold = simple_strtol(str + 15, NULL, 0);
1832 		if ((strncmp(str, "idle-period=", 12) == 0) ||
1833 		    (strncmp(str, "idle_period=", 12) == 0))
1834 			idle_period = simple_strtol(str + 12, NULL, 0);
1835 		invert = (strncmp(str, "no-", 3) == 0) ||
1836 			(strncmp(str, "no_", 3) == 0);
1837 		if (invert)
1838 			str += 3;
1839 		if (strncmp(str, "debug", 5) == 0)
1840 			debug = !invert;
1841 		if ((strncmp(str, "power-off", 9) == 0) ||
1842 		    (strncmp(str, "power_off", 9) == 0))
1843 			power_off = !invert;
1844 		if (strncmp(str, "smp", 3) == 0) {
1845 			smp = !invert;
1846 			idle_threshold = 100;
1847 		}
1848 		if ((strncmp(str, "allow-ints", 10) == 0) ||
1849 		    (strncmp(str, "allow_ints", 10) == 0))
1850 			apm_info.allow_ints = !invert;
1851 		if ((strncmp(str, "broken-psr", 10) == 0) ||
1852 		    (strncmp(str, "broken_psr", 10) == 0))
1853 			apm_info.get_power_status_broken = !invert;
1854 		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1855 		    (strncmp(str, "realmode_power_off", 18) == 0))
1856 			apm_info.realmode_power_off = !invert;
1857 		str = strchr(str, ',');
1858 		if (str != NULL)
1859 			str += strspn(str, ", \t");
1860 	}
1861 	return 1;
1862 }
1863 
1864 __setup("apm=", apm_setup);
1865 #endif
1866 
1867 static const struct file_operations apm_bios_fops = {
1868 	.owner		= THIS_MODULE,
1869 	.read		= do_read,
1870 	.poll		= do_poll,
1871 	.unlocked_ioctl	= do_ioctl,
1872 	.open		= do_open,
1873 	.release	= do_release,
1874 };
1875 
1876 static struct miscdevice apm_device = {
1877 	APM_MINOR_DEV,
1878 	"apm_bios",
1879 	&apm_bios_fops
1880 };
1881 
1882 
1883 /* Simple "print if true" callback */
1884 static int __init print_if_true(const struct dmi_system_id *d)
1885 {
1886 	printk("%s\n", d->ident);
1887 	return 0;
1888 }
1889 
1890 /*
1891  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1892  * disabled before the suspend. Linux used to get terribly confused by that.
1893  */
1894 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1895 {
1896 	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1897 	       "workaround hopefully not needed.\n", d->ident);
1898 	return 0;
1899 }
1900 
1901 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1902 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1903 {
1904 	if (apm_info.realmode_power_off == 0) {
1905 		apm_info.realmode_power_off = 1;
1906 		printk(KERN_INFO "%s bios detected. "
1907 		       "Using realmode poweroff only.\n", d->ident);
1908 	}
1909 	return 0;
1910 }
1911 
1912 /* Some laptops require interrupts to be enabled during APM calls */
1913 static int __init set_apm_ints(const struct dmi_system_id *d)
1914 {
1915 	if (apm_info.allow_ints == 0) {
1916 		apm_info.allow_ints = 1;
1917 		printk(KERN_INFO "%s machine detected. "
1918 		       "Enabling interrupts during APM calls.\n", d->ident);
1919 	}
1920 	return 0;
1921 }
1922 
1923 /* Some APM bioses corrupt memory or just plain do not work */
1924 static int __init apm_is_horked(const struct dmi_system_id *d)
1925 {
1926 	if (apm_info.disabled == 0) {
1927 		apm_info.disabled = 1;
1928 		printk(KERN_INFO "%s machine detected. "
1929 		       "Disabling APM.\n", d->ident);
1930 	}
1931 	return 0;
1932 }
1933 
1934 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1935 {
1936 	if (apm_info.disabled == 0) {
1937 		apm_info.disabled = 1;
1938 		printk(KERN_INFO "%s machine detected. "
1939 		       "Disabling APM.\n", d->ident);
1940 		printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
1941 		printk(KERN_INFO "download from support.intel.com \n");
1942 	}
1943 	return 0;
1944 }
1945 
1946 /* Some APM bioses hang on APM idle calls */
1947 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1948 {
1949 	if (apm_info.forbid_idle == 0) {
1950 		apm_info.forbid_idle = 1;
1951 		printk(KERN_INFO "%s machine detected. "
1952 		       "Disabling APM idle calls.\n", d->ident);
1953 	}
1954 	return 0;
1955 }
1956 
1957 /*
1958  *  Check for clue free BIOS implementations who use
1959  *  the following QA technique
1960  *
1961  *      [ Write BIOS Code ]<------
1962  *               |                ^
1963  *      < Does it Compile >----N--
1964  *               |Y               ^
1965  *	< Does it Boot Win98 >-N--
1966  *               |Y
1967  *           [Ship It]
1968  *
1969  *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
1970  *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
1971  */
1972 static int __init broken_apm_power(const struct dmi_system_id *d)
1973 {
1974 	apm_info.get_power_status_broken = 1;
1975 	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
1976 	       "disabling power status reporting.\n");
1977 	return 0;
1978 }
1979 
1980 /*
1981  * This bios swaps the APM minute reporting bytes over (Many sony laptops
1982  * have this problem).
1983  */
1984 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
1985 {
1986 	apm_info.get_power_status_swabinminutes = 1;
1987 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
1988 	       "in minutes and wrong byte order.\n");
1989 	return 0;
1990 }
1991 
1992 static struct dmi_system_id __initdata apm_dmi_table[] = {
1993 	{
1994 		print_if_true,
1995 		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
1996 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
1997 			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
1998 	},
1999 	{	/* Handle problems with APM on the C600 */
2000 		broken_ps2_resume, "Dell Latitude C600",
2001 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2002 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2003 	},
2004 	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2005 		set_apm_ints, "Dell Latitude",
2006 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2007 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2008 	},
2009 	{	/* APM crashes */
2010 		apm_is_horked, "Dell Inspiron 2500",
2011 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2012 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2013 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2014 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2015 	},
2016 	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2017 		set_apm_ints, "Dell Inspiron", {
2018 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2019 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2020 	},
2021 	{	/* Handle problems with APM on Inspiron 5000e */
2022 		broken_apm_power, "Dell Inspiron 5000e",
2023 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2024 			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2025 			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2026 	},
2027 	{	/* Handle problems with APM on Inspiron 2500 */
2028 		broken_apm_power, "Dell Inspiron 2500",
2029 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2030 			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2031 			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2032 	},
2033 	{	/* APM crashes */
2034 		apm_is_horked, "Dell Dimension 4100",
2035 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2036 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2037 			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2038 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2039 	},
2040 	{	/* Allow interrupts during suspend on Compaq Laptops*/
2041 		set_apm_ints, "Compaq 12XL125",
2042 		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2043 			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2044 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2045 			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2046 	},
2047 	{	/* Allow interrupts during APM or the clock goes slow */
2048 		set_apm_ints, "ASUSTeK",
2049 		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2050 			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2051 	},
2052 	{	/* APM blows on shutdown */
2053 		apm_is_horked, "ABIT KX7-333[R]",
2054 		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2055 			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2056 	},
2057 	{	/* APM crashes */
2058 		apm_is_horked, "Trigem Delhi3",
2059 		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2060 			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2061 	},
2062 	{	/* APM crashes */
2063 		apm_is_horked, "Fujitsu-Siemens",
2064 		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2065 			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2066 	},
2067 	{	/* APM crashes */
2068 		apm_is_horked_d850md, "Intel D850MD",
2069 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2070 			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2071 	},
2072 	{	/* APM crashes */
2073 		apm_is_horked, "Intel D810EMO",
2074 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2075 			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2076 	},
2077 	{	/* APM crashes */
2078 		apm_is_horked, "Dell XPS-Z",
2079 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2080 			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2081 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2082 	},
2083 	{	/* APM crashes */
2084 		apm_is_horked, "Sharp PC-PJ/AX",
2085 		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2086 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2087 			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2088 			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2089 	},
2090 	{	/* APM crashes */
2091 		apm_is_horked, "Dell Inspiron 2500",
2092 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2093 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2094 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2095 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2096 	},
2097 	{	/* APM idle hangs */
2098 		apm_likes_to_melt, "Jabil AMD",
2099 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2100 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2101 	},
2102 	{	/* APM idle hangs */
2103 		apm_likes_to_melt, "AMI Bios",
2104 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2105 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2106 	},
2107 	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2108 		swab_apm_power_in_minutes, "Sony VAIO",
2109 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2110 			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2111 			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2112 	},
2113 	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2114 		swab_apm_power_in_minutes, "Sony VAIO",
2115 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2116 			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2117 			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2118 	},
2119 	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2120 		swab_apm_power_in_minutes, "Sony VAIO",
2121 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2122 			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2123 			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2124 	},
2125 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2126 		swab_apm_power_in_minutes, "Sony VAIO",
2127 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2128 			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2129 			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2130 	},
2131 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2132 		swab_apm_power_in_minutes, "Sony VAIO",
2133 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2134 			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2135 			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2136 	},
2137 	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2138 		swab_apm_power_in_minutes, "Sony VAIO",
2139 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2140 			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2141 			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2142 	},
2143 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2144 		swab_apm_power_in_minutes, "Sony VAIO",
2145 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2146 			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2147 			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2148 	},
2149 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2150 		swab_apm_power_in_minutes, "Sony VAIO",
2151 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2152 			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2153 			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2154 	},
2155 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2156 		swab_apm_power_in_minutes, "Sony VAIO",
2157 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2158 			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2159 			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2160 	},
2161 	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2162 		swab_apm_power_in_minutes, "Sony VAIO",
2163 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2164 			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2165 			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2166 	},
2167 
2168 	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2169 		swab_apm_power_in_minutes, "Sony VAIO",
2170 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2171 			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2172 			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2173 	},
2174 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2175 		swab_apm_power_in_minutes, "Sony VAIO",
2176 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2177 			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2178 			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2179 	},
2180 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2181 		swab_apm_power_in_minutes, "Sony VAIO",
2182 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2183 			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2184 			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2185 	},
2186 	{	/* broken PM poweroff bios */
2187 		set_realmode_power_off, "Award Software v4.60 PGMA",
2188 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2189 			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2190 			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2191 	},
2192 
2193 	/* Generic per vendor APM settings  */
2194 
2195 	{	/* Allow interrupts during suspend on IBM laptops */
2196 		set_apm_ints, "IBM",
2197 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2198 	},
2199 
2200 	{ }
2201 };
2202 
2203 /*
2204  * Just start the APM thread. We do NOT want to do APM BIOS
2205  * calls from anything but the APM thread, if for no other reason
2206  * than the fact that we don't trust the APM BIOS. This way,
2207  * most common APM BIOS problems that lead to protection errors
2208  * etc will have at least some level of being contained...
2209  *
2210  * In short, if something bad happens, at least we have a choice
2211  * of just killing the apm thread..
2212  */
2213 static int __init apm_init(void)
2214 {
2215 	struct desc_struct *gdt;
2216 	int err;
2217 
2218 	dmi_check_system(apm_dmi_table);
2219 
2220 	if (apm_info.bios.version == 0 || paravirt_enabled()) {
2221 		printk(KERN_INFO "apm: BIOS not found.\n");
2222 		return -ENODEV;
2223 	}
2224 	printk(KERN_INFO
2225 	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2226 	       ((apm_info.bios.version >> 8) & 0xff),
2227 	       (apm_info.bios.version & 0xff),
2228 	       apm_info.bios.flags,
2229 	       driver_version);
2230 	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2231 		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2232 		return -ENODEV;
2233 	}
2234 
2235 	if (allow_ints)
2236 		apm_info.allow_ints = 1;
2237 	if (broken_psr)
2238 		apm_info.get_power_status_broken = 1;
2239 	if (realmode_power_off)
2240 		apm_info.realmode_power_off = 1;
2241 	/* User can override, but default is to trust DMI */
2242 	if (apm_disabled != -1)
2243 		apm_info.disabled = apm_disabled;
2244 
2245 	/*
2246 	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2247 	 * but is reportedly a 1.0 BIOS.
2248 	 */
2249 	if (apm_info.bios.version == 0x001)
2250 		apm_info.bios.version = 0x100;
2251 
2252 	/* BIOS < 1.2 doesn't set cseg_16_len */
2253 	if (apm_info.bios.version < 0x102)
2254 		apm_info.bios.cseg_16_len = 0; /* 64k */
2255 
2256 	if (debug) {
2257 		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2258 			apm_info.bios.cseg, apm_info.bios.offset,
2259 			apm_info.bios.cseg_16, apm_info.bios.dseg);
2260 		if (apm_info.bios.version > 0x100)
2261 			printk(" cseg len %x, dseg len %x",
2262 				apm_info.bios.cseg_len,
2263 				apm_info.bios.dseg_len);
2264 		if (apm_info.bios.version > 0x101)
2265 			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2266 		printk("\n");
2267 	}
2268 
2269 	if (apm_info.disabled) {
2270 		printk(KERN_NOTICE "apm: disabled on user request.\n");
2271 		return -ENODEV;
2272 	}
2273 	if ((num_online_cpus() > 1) && !power_off && !smp) {
2274 		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2275 		apm_info.disabled = 1;
2276 		return -ENODEV;
2277 	}
2278 	if (pm_flags & PM_ACPI) {
2279 		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2280 		apm_info.disabled = 1;
2281 		return -ENODEV;
2282 	}
2283 	pm_flags |= PM_APM;
2284 
2285 	/*
2286 	 * Set up a segment that references the real mode segment 0x40
2287 	 * that extends up to the end of page zero (that we have reserved).
2288 	 * This is for buggy BIOS's that refer to (real mode) segment 0x40
2289 	 * even though they are called in protected mode.
2290 	 */
2291 	set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2292 	_set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2293 
2294 	/*
2295 	 * Set up the long jump entry point to the APM BIOS, which is called
2296 	 * from inline assembly.
2297 	 */
2298 	apm_bios_entry.offset = apm_info.bios.offset;
2299 	apm_bios_entry.segment = APM_CS;
2300 
2301 	/*
2302 	 * The APM 1.1 BIOS is supposed to provide limit information that it
2303 	 * recognizes.  Many machines do this correctly, but many others do
2304 	 * not restrict themselves to their claimed limit.  When this happens,
2305 	 * they will cause a segmentation violation in the kernel at boot time.
2306 	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2307 	 *
2308 	 * Note we only set APM segments on CPU zero, since we pin the APM
2309 	 * code to that CPU.
2310 	 */
2311 	gdt = get_cpu_gdt_table(0);
2312 	set_base(gdt[APM_CS >> 3],
2313 		 __va((unsigned long)apm_info.bios.cseg << 4));
2314 	set_base(gdt[APM_CS_16 >> 3],
2315 		 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2316 	set_base(gdt[APM_DS >> 3],
2317 		 __va((unsigned long)apm_info.bios.dseg << 4));
2318 
2319 	proc_create("apm", 0, NULL, &apm_file_ops);
2320 
2321 	kapmd_task = kthread_create(apm, NULL, "kapmd");
2322 	if (IS_ERR(kapmd_task)) {
2323 		printk(KERN_ERR "apm: disabled - Unable to start kernel "
2324 				"thread.\n");
2325 		err = PTR_ERR(kapmd_task);
2326 		kapmd_task = NULL;
2327 		remove_proc_entry("apm", NULL);
2328 		return err;
2329 	}
2330 	wake_up_process(kapmd_task);
2331 
2332 	if (num_online_cpus() > 1 && !smp) {
2333 		printk(KERN_NOTICE
2334 		       "apm: disabled - APM is not SMP safe (power off active).\n");
2335 		return 0;
2336 	}
2337 
2338 	/*
2339 	 * Note we don't actually care if the misc_device cannot be registered.
2340 	 * this driver can do its job without it, even if userspace can't
2341 	 * control it.  just log the error
2342 	 */
2343 	if (misc_register(&apm_device))
2344 		printk(KERN_WARNING "apm: Could not register misc device.\n");
2345 
2346 	if (HZ != 100)
2347 		idle_period = (idle_period * HZ) / 100;
2348 	if (idle_threshold < 100) {
2349 		original_pm_idle = pm_idle;
2350 		pm_idle  = apm_cpu_idle;
2351 		set_pm_idle = 1;
2352 	}
2353 
2354 	return 0;
2355 }
2356 
2357 static void __exit apm_exit(void)
2358 {
2359 	int error;
2360 
2361 	if (set_pm_idle) {
2362 		pm_idle = original_pm_idle;
2363 		/*
2364 		 * We are about to unload the current idle thread pm callback
2365 		 * (pm_idle), Wait for all processors to update cached/local
2366 		 * copies of pm_idle before proceeding.
2367 		 */
2368 		cpu_idle_wait();
2369 	}
2370 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2371 	    && (apm_info.connection_version > 0x0100)) {
2372 		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2373 		if (error)
2374 			apm_error("disengage power management", error);
2375 	}
2376 	misc_deregister(&apm_device);
2377 	remove_proc_entry("apm", NULL);
2378 	if (power_off)
2379 		pm_power_off = NULL;
2380 	if (kapmd_task) {
2381 		kthread_stop(kapmd_task);
2382 		kapmd_task = NULL;
2383 	}
2384 	pm_flags &= ~PM_APM;
2385 }
2386 
2387 module_init(apm_init);
2388 module_exit(apm_exit);
2389 
2390 MODULE_AUTHOR("Stephen Rothwell");
2391 MODULE_DESCRIPTION("Advanced Power Management");
2392 MODULE_LICENSE("GPL");
2393 module_param(debug, bool, 0644);
2394 MODULE_PARM_DESC(debug, "Enable debug mode");
2395 module_param(power_off, bool, 0444);
2396 MODULE_PARM_DESC(power_off, "Enable power off");
2397 module_param(bounce_interval, int, 0444);
2398 MODULE_PARM_DESC(bounce_interval,
2399 		"Set the number of ticks to ignore suspend bounces");
2400 module_param(allow_ints, bool, 0444);
2401 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2402 module_param(broken_psr, bool, 0444);
2403 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2404 module_param(realmode_power_off, bool, 0444);
2405 MODULE_PARM_DESC(realmode_power_off,
2406 		"Switch to real mode before powering off");
2407 module_param(idle_threshold, int, 0444);
2408 MODULE_PARM_DESC(idle_threshold,
2409 	"System idle percentage above which to make APM BIOS idle calls");
2410 module_param(idle_period, int, 0444);
2411 MODULE_PARM_DESC(idle_period,
2412 	"Period (in sec/100) over which to caculate the idle percentage");
2413 module_param(smp, bool, 0444);
2414 MODULE_PARM_DESC(smp,
2415 	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2416 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2417