xref: /openbmc/linux/arch/x86/kernel/apm_32.c (revision f42b3800)
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/types.h>
208 #include <linux/stddef.h>
209 #include <linux/timer.h>
210 #include <linux/fcntl.h>
211 #include <linux/slab.h>
212 #include <linux/stat.h>
213 #include <linux/proc_fs.h>
214 #include <linux/seq_file.h>
215 #include <linux/miscdevice.h>
216 #include <linux/apm_bios.h>
217 #include <linux/init.h>
218 #include <linux/time.h>
219 #include <linux/sched.h>
220 #include <linux/pm.h>
221 #include <linux/pm_legacy.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 
232 #include <asm/system.h>
233 #include <asm/uaccess.h>
234 #include <asm/desc.h>
235 #include <asm/i8253.h>
236 #include <asm/paravirt.h>
237 #include <asm/reboot.h>
238 
239 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
240 extern int (*console_blank_hook)(int);
241 #endif
242 
243 /*
244  * The apm_bios device is one of the misc char devices.
245  * This is its minor number.
246  */
247 #define	APM_MINOR_DEV	134
248 
249 /*
250  * See Documentation/Config.help for the configuration options.
251  *
252  * Various options can be changed at boot time as follows:
253  * (We allow underscores for compatibility with the modules code)
254  *	apm=on/off			enable/disable APM
255  *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
256  *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
257  *	    [no-]realmode[-_]power[-_]off	switch to real mode before
258  *	    					powering off
259  *	    [no-]debug			log some debugging messages
260  *	    [no-]power[-_]off		power off on shutdown
261  *	    [no-]smp			Use apm even on an SMP box
262  *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
263  *	    				bounces
264  *          idle[-_]threshold=<n>       System idle percentage above which to
265  *                                      make APM BIOS idle calls. Set it to
266  *                                      100 to disable.
267  *          idle[-_]period=<n>          Period (in 1/100s of a second) over
268  *                                      which the idle percentage is
269  *                                      calculated.
270  */
271 
272 /* KNOWN PROBLEM MACHINES:
273  *
274  * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
275  *                         [Confirmed by TI representative]
276  * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
277  *                    [Confirmed by BIOS disassembly]
278  *                    [This may work now ...]
279  * P: Toshiba 1950S: battery life information only gets updated after resume
280  * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
281  * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
282  * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
283  * 	Neale Banks <neale@lowendale.com.au> December 2000
284  *
285  * Legend: U = unusable with APM patches
286  *         P = partially usable with APM patches
287  */
288 
289 /*
290  * Define as 1 to make the driver always call the APM BIOS busy
291  * routine even if the clock was not reported as slowed by the
292  * idle routine.  Otherwise, define as 0.
293  */
294 #define ALWAYS_CALL_BUSY   1
295 
296 /*
297  * Define to make the APM BIOS calls zero all data segment registers (so
298  * that an incorrect BIOS implementation will cause a kernel panic if it
299  * tries to write to arbitrary memory).
300  */
301 #define APM_ZERO_SEGS
302 
303 #include "apm.h"
304 
305 /*
306  * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
307  * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
308  * David Chen <chen@ctpa04.mit.edu>
309  */
310 #undef INIT_TIMER_AFTER_SUSPEND
311 
312 #ifdef INIT_TIMER_AFTER_SUSPEND
313 #include <linux/timex.h>
314 #include <asm/io.h>
315 #include <linux/delay.h>
316 #endif
317 
318 /*
319  * Need to poll the APM BIOS every second
320  */
321 #define APM_CHECK_TIMEOUT	(HZ)
322 
323 /*
324  * Ignore suspend events for this amount of time after a resume
325  */
326 #define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
327 
328 /*
329  * Maximum number of events stored
330  */
331 #define APM_MAX_EVENTS		20
332 
333 /*
334  * The per-file APM data
335  */
336 struct apm_user {
337 	int		magic;
338 	struct apm_user *next;
339 	unsigned int	suser: 1;
340 	unsigned int	writer: 1;
341 	unsigned int	reader: 1;
342 	unsigned int	suspend_wait: 1;
343 	int		suspend_result;
344 	int		suspends_pending;
345 	int		standbys_pending;
346 	int		suspends_read;
347 	int		standbys_read;
348 	int		event_head;
349 	int		event_tail;
350 	apm_event_t	events[APM_MAX_EVENTS];
351 };
352 
353 /*
354  * The magic number in apm_user
355  */
356 #define APM_BIOS_MAGIC		0x4101
357 
358 /*
359  * idle percentage above which bios idle calls are done
360  */
361 #ifdef CONFIG_APM_CPU_IDLE
362 #define DEFAULT_IDLE_THRESHOLD	95
363 #else
364 #define DEFAULT_IDLE_THRESHOLD	100
365 #endif
366 #define DEFAULT_IDLE_PERIOD	(100 / 3)
367 
368 /*
369  * Local variables
370  */
371 static struct {
372 	unsigned long	offset;
373 	unsigned short	segment;
374 } apm_bios_entry;
375 static int clock_slowed;
376 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
377 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
378 static int set_pm_idle;
379 static int suspends_pending;
380 static int standbys_pending;
381 static int ignore_sys_suspend;
382 static int ignore_normal_resume;
383 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
384 
385 static int debug __read_mostly;
386 static int smp __read_mostly;
387 static int apm_disabled = -1;
388 #ifdef CONFIG_SMP
389 static int power_off;
390 #else
391 static int power_off = 1;
392 #endif
393 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
394 static int realmode_power_off = 1;
395 #else
396 static int realmode_power_off;
397 #endif
398 #ifdef CONFIG_APM_ALLOW_INTS
399 static int allow_ints = 1;
400 #else
401 static int allow_ints;
402 #endif
403 static int broken_psr;
404 
405 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
406 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
407 static struct apm_user *user_list;
408 static DEFINE_SPINLOCK(user_list_lock);
409 static const struct desc_struct	bad_bios_desc = { { { 0, 0x00409200 } } };
410 
411 static const char driver_version[] = "1.16ac";	/* no spaces */
412 
413 static struct task_struct *kapmd_task;
414 
415 /*
416  *	APM event names taken from the APM 1.2 specification. These are
417  *	the message codes that the BIOS uses to tell us about events
418  */
419 static const char * const apm_event_name[] = {
420 	"system standby",
421 	"system suspend",
422 	"normal resume",
423 	"critical resume",
424 	"low battery",
425 	"power status change",
426 	"update time",
427 	"critical suspend",
428 	"user standby",
429 	"user suspend",
430 	"system standby resume",
431 	"capabilities change"
432 };
433 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
434 
435 typedef struct lookup_t {
436 	int	key;
437 	char 	*msg;
438 } lookup_t;
439 
440 /*
441  *	The BIOS returns a set of standard error codes in AX when the
442  *	carry flag is set.
443  */
444 
445 static const lookup_t error_table[] = {
446 /* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
447 	{ APM_DISABLED,		"Power management disabled" },
448 	{ APM_CONNECTED,	"Real mode interface already connected" },
449 	{ APM_NOT_CONNECTED,	"Interface not connected" },
450 	{ APM_16_CONNECTED,	"16 bit interface already connected" },
451 /* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
452 	{ APM_32_CONNECTED,	"32 bit interface already connected" },
453 	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
454 	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
455 	{ APM_BAD_PARAM,	"Parameter out of range" },
456 	{ APM_NOT_ENGAGED,	"Interface not engaged" },
457 	{ APM_BAD_FUNCTION,     "Function not supported" },
458 	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
459 	{ APM_BAD_STATE,	"Unable to enter requested state" },
460 /* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
461 	{ APM_NO_ERROR,		"BIOS did not set a return code" },
462 	{ APM_NOT_PRESENT,	"No APM present" }
463 };
464 #define ERROR_COUNT	ARRAY_SIZE(error_table)
465 
466 /**
467  *	apm_error	-	display an APM error
468  *	@str: information string
469  *	@err: APM BIOS return code
470  *
471  *	Write a meaningful log entry to the kernel log in the event of
472  *	an APM error.
473  */
474 
475 static void apm_error(char *str, int err)
476 {
477 	int i;
478 
479 	for (i = 0; i < ERROR_COUNT; i++)
480 		if (error_table[i].key == err)
481 			break;
482 	if (i < ERROR_COUNT)
483 		printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
484 	else
485 		printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
486 		       str, err);
487 }
488 
489 /*
490  * Lock APM functionality to physical CPU 0
491  */
492 
493 #ifdef CONFIG_SMP
494 
495 static cpumask_t apm_save_cpus(void)
496 {
497 	cpumask_t x = current->cpus_allowed;
498 	/* Some bioses don't like being called from CPU != 0 */
499 	set_cpus_allowed(current, cpumask_of_cpu(0));
500 	BUG_ON(smp_processor_id() != 0);
501 	return x;
502 }
503 
504 static inline void apm_restore_cpus(cpumask_t mask)
505 {
506 	set_cpus_allowed(current, mask);
507 }
508 
509 #else
510 
511 /*
512  *	No CPU lockdown needed on a uniprocessor
513  */
514 
515 #define apm_save_cpus()		(current->cpus_allowed)
516 #define apm_restore_cpus(x)	(void)(x)
517 
518 #endif
519 
520 /*
521  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
522  * apm_info.allow_ints, we are being really paranoid here!  Not only
523  * are interrupts disabled, but all the segment registers (except SS)
524  * are saved and zeroed this means that if the BIOS tries to reference
525  * any data without explicitly loading the segment registers, the kernel
526  * will fault immediately rather than have some unforeseen circumstances
527  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
528  * this depends on CS referring to the same physical memory as DS so that
529  * DS can be zeroed before the call. Unfortunately, we can't do anything
530  * about the stack segment/pointer.  Also, we tell the compiler that
531  * everything could change.
532  *
533  * Also, we KNOW that for the non error case of apm_bios_call, there
534  * is no useful data returned in the low order 8 bits of eax.
535  */
536 
537 static inline unsigned long __apm_irq_save(void)
538 {
539 	unsigned long flags;
540 	local_save_flags(flags);
541 	if (apm_info.allow_ints) {
542 		if (irqs_disabled_flags(flags))
543 			local_irq_enable();
544 	} else
545 		local_irq_disable();
546 
547 	return flags;
548 }
549 
550 #define apm_irq_save(flags) \
551 	do { flags = __apm_irq_save(); } while (0)
552 
553 static inline void apm_irq_restore(unsigned long flags)
554 {
555 	if (irqs_disabled_flags(flags))
556 		local_irq_disable();
557 	else if (irqs_disabled())
558 		local_irq_enable();
559 }
560 
561 #ifdef APM_ZERO_SEGS
562 #	define APM_DECL_SEGS \
563 		unsigned int saved_fs; unsigned int saved_gs;
564 #	define APM_DO_SAVE_SEGS \
565 		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
566 #	define APM_DO_RESTORE_SEGS \
567 		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
568 #else
569 #	define APM_DECL_SEGS
570 #	define APM_DO_SAVE_SEGS
571 #	define APM_DO_RESTORE_SEGS
572 #endif
573 
574 /**
575  *	apm_bios_call	-	Make an APM BIOS 32bit call
576  *	@func: APM function to execute
577  *	@ebx_in: EBX register for call entry
578  *	@ecx_in: ECX register for call entry
579  *	@eax: EAX register return
580  *	@ebx: EBX register return
581  *	@ecx: ECX register return
582  *	@edx: EDX register return
583  *	@esi: ESI register return
584  *
585  *	Make an APM call using the 32bit protected mode interface. The
586  *	caller is responsible for knowing if APM BIOS is configured and
587  *	enabled. This call can disable interrupts for a long period of
588  *	time on some laptops.  The return value is in AH and the carry
589  *	flag is loaded into AL.  If there is an error, then the error
590  *	code is returned in AH (bits 8-15 of eax) and this function
591  *	returns non-zero.
592  */
593 
594 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
595 	u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
596 {
597 	APM_DECL_SEGS
598 	unsigned long		flags;
599 	cpumask_t		cpus;
600 	int			cpu;
601 	struct desc_struct	save_desc_40;
602 	struct desc_struct	*gdt;
603 
604 	cpus = apm_save_cpus();
605 
606 	cpu = get_cpu();
607 	gdt = get_cpu_gdt_table(cpu);
608 	save_desc_40 = gdt[0x40 / 8];
609 	gdt[0x40 / 8] = bad_bios_desc;
610 
611 	apm_irq_save(flags);
612 	APM_DO_SAVE_SEGS;
613 	apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
614 	APM_DO_RESTORE_SEGS;
615 	apm_irq_restore(flags);
616 	gdt[0x40 / 8] = save_desc_40;
617 	put_cpu();
618 	apm_restore_cpus(cpus);
619 
620 	return *eax & 0xff;
621 }
622 
623 /**
624  *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
625  *	@func: APM function to invoke
626  *	@ebx_in: EBX register value for BIOS call
627  *	@ecx_in: ECX register value for BIOS call
628  *	@eax: EAX register on return from the BIOS call
629  *
630  *	Make a BIOS call that returns one value only, or just status.
631  *	If there is an error, then the error code is returned in AH
632  *	(bits 8-15 of eax) and this function returns non-zero. This is
633  *	used for simpler BIOS operations. This call may hold interrupts
634  *	off for a long time on some laptops.
635  */
636 
637 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
638 {
639 	u8			error;
640 	APM_DECL_SEGS
641 	unsigned long		flags;
642 	cpumask_t		cpus;
643 	int			cpu;
644 	struct desc_struct	save_desc_40;
645 	struct desc_struct	*gdt;
646 
647 	cpus = apm_save_cpus();
648 
649 	cpu = get_cpu();
650 	gdt = get_cpu_gdt_table(cpu);
651 	save_desc_40 = gdt[0x40 / 8];
652 	gdt[0x40 / 8] = bad_bios_desc;
653 
654 	apm_irq_save(flags);
655 	APM_DO_SAVE_SEGS;
656 	error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
657 	APM_DO_RESTORE_SEGS;
658 	apm_irq_restore(flags);
659 	gdt[0x40 / 8] = save_desc_40;
660 	put_cpu();
661 	apm_restore_cpus(cpus);
662 	return error;
663 }
664 
665 /**
666  *	apm_driver_version	-	APM driver version
667  *	@val:	loaded with the APM version on return
668  *
669  *	Retrieve the APM version supported by the BIOS. This is only
670  *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
671  *	probably present.
672  *
673  *	On entry val should point to a value indicating the APM driver
674  *	version with the high byte being the major and the low byte the
675  *	minor number both in BCD
676  *
677  *	On return it will hold the BIOS revision supported in the
678  *	same format.
679  */
680 
681 static int apm_driver_version(u_short *val)
682 {
683 	u32 eax;
684 
685 	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
686 		return (eax >> 8) & 0xff;
687 	*val = eax;
688 	return APM_SUCCESS;
689 }
690 
691 /**
692  *	apm_get_event	-	get an APM event from the BIOS
693  *	@event: pointer to the event
694  *	@info: point to the event information
695  *
696  *	The APM BIOS provides a polled information for event
697  *	reporting. The BIOS expects to be polled at least every second
698  *	when events are pending. When a message is found the caller should
699  *	poll until no more messages are present.  However, this causes
700  *	problems on some laptops where a suspend event notification is
701  *	not cleared until it is acknowledged.
702  *
703  *	Additional information is returned in the info pointer, providing
704  *	that APM 1.2 is in use. If no messges are pending the value 0x80
705  *	is returned (No power management events pending).
706  */
707 
708 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
709 {
710 	u32 eax;
711 	u32 ebx;
712 	u32 ecx;
713 	u32 dummy;
714 
715 	if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
716 			  &dummy, &dummy))
717 		return (eax >> 8) & 0xff;
718 	*event = ebx;
719 	if (apm_info.connection_version < 0x0102)
720 		*info = ~0; /* indicate info not valid */
721 	else
722 		*info = ecx;
723 	return APM_SUCCESS;
724 }
725 
726 /**
727  *	set_power_state	-	set the power management state
728  *	@what: which items to transition
729  *	@state: state to transition to
730  *
731  *	Request an APM change of state for one or more system devices. The
732  *	processor state must be transitioned last of all. what holds the
733  *	class of device in the upper byte and the device number (0xFF for
734  *	all) for the object to be transitioned.
735  *
736  *	The state holds the state to transition to, which may in fact
737  *	be an acceptance of a BIOS requested state change.
738  */
739 
740 static int set_power_state(u_short what, u_short state)
741 {
742 	u32 eax;
743 
744 	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
745 		return (eax >> 8) & 0xff;
746 	return APM_SUCCESS;
747 }
748 
749 /**
750  *	set_system_power_state - set system wide power state
751  *	@state: which state to enter
752  *
753  *	Transition the entire system into a new APM power state.
754  */
755 
756 static int set_system_power_state(u_short state)
757 {
758 	return set_power_state(APM_DEVICE_ALL, state);
759 }
760 
761 /**
762  *	apm_do_idle	-	perform power saving
763  *
764  *	This function notifies the BIOS that the processor is (in the view
765  *	of the OS) idle. It returns -1 in the event that the BIOS refuses
766  *	to handle the idle request. On a success the function returns 1
767  *	if the BIOS did clock slowing or 0 otherwise.
768  */
769 
770 static int apm_do_idle(void)
771 {
772 	u32 eax;
773 	u8 ret = 0;
774 	int idled = 0;
775 	int polling;
776 
777 	polling = !!(current_thread_info()->status & TS_POLLING);
778 	if (polling) {
779 		current_thread_info()->status &= ~TS_POLLING;
780 		/*
781 		 * TS_POLLING-cleared state must be visible before we
782 		 * test NEED_RESCHED:
783 		 */
784 		smp_mb();
785 	}
786 	if (!need_resched()) {
787 		idled = 1;
788 		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
789 	}
790 	if (polling)
791 		current_thread_info()->status |= TS_POLLING;
792 
793 	if (!idled)
794 		return 0;
795 
796 	if (ret) {
797 		static unsigned long t;
798 
799 		/* This always fails on some SMP boards running UP kernels.
800 		 * Only report the failure the first 5 times.
801 		 */
802 		if (++t < 5) {
803 			printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
804 			       (eax >> 8) & 0xff);
805 			t = jiffies;
806 		}
807 		return -1;
808 	}
809 	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
810 	return clock_slowed;
811 }
812 
813 /**
814  *	apm_do_busy	-	inform the BIOS the CPU is busy
815  *
816  *	Request that the BIOS brings the CPU back to full performance.
817  */
818 
819 static void apm_do_busy(void)
820 {
821 	u32 dummy;
822 
823 	if (clock_slowed || ALWAYS_CALL_BUSY) {
824 		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
825 		clock_slowed = 0;
826 	}
827 }
828 
829 /*
830  * If no process has really been interested in
831  * the CPU for some time, we want to call BIOS
832  * power management - we probably want
833  * to conserve power.
834  */
835 #define IDLE_CALC_LIMIT	(HZ * 100)
836 #define IDLE_LEAKY_MAX	16
837 
838 static void (*original_pm_idle)(void) __read_mostly;
839 
840 /**
841  * apm_cpu_idle		-	cpu idling for APM capable Linux
842  *
843  * This is the idling function the kernel executes when APM is available. It
844  * tries to do BIOS powermanagement based on the average system idle time.
845  * Furthermore it calls the system default idle routine.
846  */
847 
848 static void apm_cpu_idle(void)
849 {
850 	static int use_apm_idle; /* = 0 */
851 	static unsigned int last_jiffies; /* = 0 */
852 	static unsigned int last_stime; /* = 0 */
853 
854 	int apm_idle_done = 0;
855 	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
856 	unsigned int bucket;
857 
858 recalc:
859 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
860 		use_apm_idle = 0;
861 		last_jiffies = jiffies;
862 		last_stime = current->stime;
863 	} else if (jiffies_since_last_check > idle_period) {
864 		unsigned int idle_percentage;
865 
866 		idle_percentage = current->stime - last_stime;
867 		idle_percentage *= 100;
868 		idle_percentage /= jiffies_since_last_check;
869 		use_apm_idle = (idle_percentage > idle_threshold);
870 		if (apm_info.forbid_idle)
871 			use_apm_idle = 0;
872 		last_jiffies = jiffies;
873 		last_stime = current->stime;
874 	}
875 
876 	bucket = IDLE_LEAKY_MAX;
877 
878 	while (!need_resched()) {
879 		if (use_apm_idle) {
880 			unsigned int t;
881 
882 			t = jiffies;
883 			switch (apm_do_idle()) {
884 			case 0:
885 				apm_idle_done = 1;
886 				if (t != jiffies) {
887 					if (bucket) {
888 						bucket = IDLE_LEAKY_MAX;
889 						continue;
890 					}
891 				} else if (bucket) {
892 					bucket--;
893 					continue;
894 				}
895 				break;
896 			case 1:
897 				apm_idle_done = 1;
898 				break;
899 			default: /* BIOS refused */
900 				break;
901 			}
902 		}
903 		if (original_pm_idle)
904 			original_pm_idle();
905 		else
906 			default_idle();
907 		jiffies_since_last_check = jiffies - last_jiffies;
908 		if (jiffies_since_last_check > idle_period)
909 			goto recalc;
910 	}
911 
912 	if (apm_idle_done)
913 		apm_do_busy();
914 }
915 
916 /**
917  *	apm_power_off	-	ask the BIOS to power off
918  *
919  *	Handle the power off sequence. This is the one piece of code we
920  *	will execute even on SMP machines. In order to deal with BIOS
921  *	bugs we support real mode APM BIOS power off calls. We also make
922  *	the SMP call on CPU0 as some systems will only honour this call
923  *	on their first cpu.
924  */
925 
926 static void apm_power_off(void)
927 {
928 	unsigned char po_bios_call[] = {
929 		0xb8, 0x00, 0x10,	/* movw  $0x1000,ax  */
930 		0x8e, 0xd0,		/* movw  ax,ss       */
931 		0xbc, 0x00, 0xf0,	/* movw  $0xf000,sp  */
932 		0xb8, 0x07, 0x53,	/* movw  $0x5307,ax  */
933 		0xbb, 0x01, 0x00,	/* movw  $0x0001,bx  */
934 		0xb9, 0x03, 0x00,	/* movw  $0x0003,cx  */
935 		0xcd, 0x15		/* int   $0x15       */
936 	};
937 
938 	/* Some bioses don't like being called from CPU != 0 */
939 	if (apm_info.realmode_power_off) {
940 		(void)apm_save_cpus();
941 		machine_real_restart(po_bios_call, sizeof(po_bios_call));
942 	} else {
943 		(void)set_system_power_state(APM_STATE_OFF);
944 	}
945 }
946 
947 #ifdef CONFIG_APM_DO_ENABLE
948 
949 /**
950  *	apm_enable_power_management - enable BIOS APM power management
951  *	@enable: enable yes/no
952  *
953  *	Enable or disable the APM BIOS power services.
954  */
955 
956 static int apm_enable_power_management(int enable)
957 {
958 	u32 eax;
959 
960 	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
961 		return APM_NOT_ENGAGED;
962 	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
963 				 enable, &eax))
964 		return (eax >> 8) & 0xff;
965 	if (enable)
966 		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
967 	else
968 		apm_info.bios.flags |= APM_BIOS_DISABLED;
969 	return APM_SUCCESS;
970 }
971 #endif
972 
973 /**
974  *	apm_get_power_status	-	get current power state
975  *	@status: returned status
976  *	@bat: battery info
977  *	@life: estimated life
978  *
979  *	Obtain the current power status from the APM BIOS. We return a
980  *	status which gives the rough battery status, and current power
981  *	source. The bat value returned give an estimate as a percentage
982  *	of life and a status value for the battery. The estimated life
983  *	if reported is a lifetime in secodnds/minutes at current powwer
984  *	consumption.
985  */
986 
987 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
988 {
989 	u32 eax;
990 	u32 ebx;
991 	u32 ecx;
992 	u32 edx;
993 	u32 dummy;
994 
995 	if (apm_info.get_power_status_broken)
996 		return APM_32_UNSUPPORTED;
997 	if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
998 			  &eax, &ebx, &ecx, &edx, &dummy))
999 		return (eax >> 8) & 0xff;
1000 	*status = ebx;
1001 	*bat = ecx;
1002 	if (apm_info.get_power_status_swabinminutes) {
1003 		*life = swab16((u16)edx);
1004 		*life |= 0x8000;
1005 	} else
1006 		*life = edx;
1007 	return APM_SUCCESS;
1008 }
1009 
1010 #if 0
1011 static int apm_get_battery_status(u_short which, u_short *status,
1012 				  u_short *bat, u_short *life, u_short *nbat)
1013 {
1014 	u32 eax;
1015 	u32 ebx;
1016 	u32 ecx;
1017 	u32 edx;
1018 	u32 esi;
1019 
1020 	if (apm_info.connection_version < 0x0102) {
1021 		/* pretend we only have one battery. */
1022 		if (which != 1)
1023 			return APM_BAD_DEVICE;
1024 		*nbat = 1;
1025 		return apm_get_power_status(status, bat, life);
1026 	}
1027 
1028 	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1029 			  &ebx, &ecx, &edx, &esi))
1030 		return (eax >> 8) & 0xff;
1031 	*status = ebx;
1032 	*bat = ecx;
1033 	*life = edx;
1034 	*nbat = esi;
1035 	return APM_SUCCESS;
1036 }
1037 #endif
1038 
1039 /**
1040  *	apm_engage_power_management	-	enable PM on a device
1041  *	@device: identity of device
1042  *	@enable: on/off
1043  *
1044  *	Activate or deactive power management on either a specific device
1045  *	or the entire system (%APM_DEVICE_ALL).
1046  */
1047 
1048 static int apm_engage_power_management(u_short device, int enable)
1049 {
1050 	u32 eax;
1051 
1052 	if ((enable == 0) && (device == APM_DEVICE_ALL)
1053 	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1054 		return APM_DISABLED;
1055 	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1056 		return (eax >> 8) & 0xff;
1057 	if (device == APM_DEVICE_ALL) {
1058 		if (enable)
1059 			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1060 		else
1061 			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1062 	}
1063 	return APM_SUCCESS;
1064 }
1065 
1066 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1067 
1068 /**
1069  *	apm_console_blank	-	blank the display
1070  *	@blank: on/off
1071  *
1072  *	Attempt to blank the console, firstly by blanking just video device
1073  *	zero, and if that fails (some BIOSes don't support it) then it blanks
1074  *	all video devices. Typically the BIOS will do laptop backlight and
1075  *	monitor powerdown for us.
1076  */
1077 
1078 static int apm_console_blank(int blank)
1079 {
1080 	int error = APM_NOT_ENGAGED; /* silence gcc */
1081 	int i;
1082 	u_short state;
1083 	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1084 
1085 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1086 
1087 	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1088 		error = set_power_state(dev[i], state);
1089 
1090 		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1091 			return 1;
1092 
1093 		if (error == APM_NOT_ENGAGED)
1094 			break;
1095 	}
1096 
1097 	if (error == APM_NOT_ENGAGED) {
1098 		static int tried;
1099 		int eng_error;
1100 		if (tried++ == 0) {
1101 			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1102 			if (eng_error) {
1103 				apm_error("set display", error);
1104 				apm_error("engage interface", eng_error);
1105 				return 0;
1106 			} else
1107 				return apm_console_blank(blank);
1108 		}
1109 	}
1110 	apm_error("set display", error);
1111 	return 0;
1112 }
1113 #endif
1114 
1115 static int queue_empty(struct apm_user *as)
1116 {
1117 	return as->event_head == as->event_tail;
1118 }
1119 
1120 static apm_event_t get_queued_event(struct apm_user *as)
1121 {
1122 	if (++as->event_tail >= APM_MAX_EVENTS)
1123 		as->event_tail = 0;
1124 	return as->events[as->event_tail];
1125 }
1126 
1127 static void queue_event(apm_event_t event, struct apm_user *sender)
1128 {
1129 	struct apm_user *as;
1130 
1131 	spin_lock(&user_list_lock);
1132 	if (user_list == NULL)
1133 		goto out;
1134 	for (as = user_list; as != NULL; as = as->next) {
1135 		if ((as == sender) || (!as->reader))
1136 			continue;
1137 		if (++as->event_head >= APM_MAX_EVENTS)
1138 			as->event_head = 0;
1139 
1140 		if (as->event_head == as->event_tail) {
1141 			static int notified;
1142 
1143 			if (notified++ == 0)
1144 			    printk(KERN_ERR "apm: an event queue overflowed\n");
1145 			if (++as->event_tail >= APM_MAX_EVENTS)
1146 				as->event_tail = 0;
1147 		}
1148 		as->events[as->event_head] = event;
1149 		if ((!as->suser) || (!as->writer))
1150 			continue;
1151 		switch (event) {
1152 		case APM_SYS_SUSPEND:
1153 		case APM_USER_SUSPEND:
1154 			as->suspends_pending++;
1155 			suspends_pending++;
1156 			break;
1157 
1158 		case APM_SYS_STANDBY:
1159 		case APM_USER_STANDBY:
1160 			as->standbys_pending++;
1161 			standbys_pending++;
1162 			break;
1163 		}
1164 	}
1165 	wake_up_interruptible(&apm_waitqueue);
1166 out:
1167 	spin_unlock(&user_list_lock);
1168 }
1169 
1170 static void reinit_timer(void)
1171 {
1172 #ifdef INIT_TIMER_AFTER_SUSPEND
1173 	unsigned long flags;
1174 
1175 	spin_lock_irqsave(&i8253_lock, flags);
1176 	/* set the clock to HZ */
1177 	outb_pit(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1178 	udelay(10);
1179 	outb_pit(LATCH & 0xff, PIT_CH0);	/* LSB */
1180 	udelay(10);
1181 	outb_pit(LATCH >> 8, PIT_CH0);	/* MSB */
1182 	udelay(10);
1183 	spin_unlock_irqrestore(&i8253_lock, flags);
1184 #endif
1185 }
1186 
1187 static int suspend(int vetoable)
1188 {
1189 	int err;
1190 	struct apm_user	*as;
1191 
1192 	if (pm_send_all(PM_SUSPEND, (void *)3)) {
1193 		/* Vetoed */
1194 		if (vetoable) {
1195 			if (apm_info.connection_version > 0x100)
1196 				set_system_power_state(APM_STATE_REJECT);
1197 			err = -EBUSY;
1198 			ignore_sys_suspend = 0;
1199 			printk(KERN_WARNING "apm: suspend was vetoed.\n");
1200 			goto out;
1201 		}
1202 		printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
1203 	}
1204 
1205 	device_suspend(PMSG_SUSPEND);
1206 	local_irq_disable();
1207 	device_power_down(PMSG_SUSPEND);
1208 
1209 	local_irq_enable();
1210 
1211 	save_processor_state();
1212 	err = set_system_power_state(APM_STATE_SUSPEND);
1213 	ignore_normal_resume = 1;
1214 	restore_processor_state();
1215 
1216 	local_irq_disable();
1217 	reinit_timer();
1218 
1219 	if (err == APM_NO_ERROR)
1220 		err = APM_SUCCESS;
1221 	if (err != APM_SUCCESS)
1222 		apm_error("suspend", err);
1223 	err = (err == APM_SUCCESS) ? 0 : -EIO;
1224 	device_power_up();
1225 	local_irq_enable();
1226 	device_resume();
1227 	pm_send_all(PM_RESUME, (void *)0);
1228 	queue_event(APM_NORMAL_RESUME, NULL);
1229  out:
1230 	spin_lock(&user_list_lock);
1231 	for (as = user_list; as != NULL; as = as->next) {
1232 		as->suspend_wait = 0;
1233 		as->suspend_result = err;
1234 	}
1235 	spin_unlock(&user_list_lock);
1236 	wake_up_interruptible(&apm_suspend_waitqueue);
1237 	return err;
1238 }
1239 
1240 static void standby(void)
1241 {
1242 	int err;
1243 
1244 	local_irq_disable();
1245 	device_power_down(PMSG_SUSPEND);
1246 	local_irq_enable();
1247 
1248 	err = set_system_power_state(APM_STATE_STANDBY);
1249 	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1250 		apm_error("standby", err);
1251 
1252 	local_irq_disable();
1253 	device_power_up();
1254 	local_irq_enable();
1255 }
1256 
1257 static apm_event_t get_event(void)
1258 {
1259 	int error;
1260 	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1261 	apm_eventinfo_t	info;
1262 
1263 	static int notified;
1264 
1265 	/* we don't use the eventinfo */
1266 	error = apm_get_event(&event, &info);
1267 	if (error == APM_SUCCESS)
1268 		return event;
1269 
1270 	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1271 		apm_error("get_event", error);
1272 
1273 	return 0;
1274 }
1275 
1276 static void check_events(void)
1277 {
1278 	apm_event_t event;
1279 	static unsigned long last_resume;
1280 	static int ignore_bounce;
1281 
1282 	while ((event = get_event()) != 0) {
1283 		if (debug) {
1284 			if (event <= NR_APM_EVENT_NAME)
1285 				printk(KERN_DEBUG "apm: received %s notify\n",
1286 				       apm_event_name[event - 1]);
1287 			else
1288 				printk(KERN_DEBUG "apm: received unknown "
1289 				       "event 0x%02x\n", event);
1290 		}
1291 		if (ignore_bounce
1292 		    && (time_after(jiffies, last_resume + bounce_interval)))
1293 			ignore_bounce = 0;
1294 
1295 		switch (event) {
1296 		case APM_SYS_STANDBY:
1297 		case APM_USER_STANDBY:
1298 			queue_event(event, NULL);
1299 			if (standbys_pending <= 0)
1300 				standby();
1301 			break;
1302 
1303 		case APM_USER_SUSPEND:
1304 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1305 			if (apm_info.connection_version > 0x100)
1306 				set_system_power_state(APM_STATE_REJECT);
1307 			break;
1308 #endif
1309 		case APM_SYS_SUSPEND:
1310 			if (ignore_bounce) {
1311 				if (apm_info.connection_version > 0x100)
1312 					set_system_power_state(APM_STATE_REJECT);
1313 				break;
1314 			}
1315 			/*
1316 			 * If we are already processing a SUSPEND,
1317 			 * then further SUSPEND events from the BIOS
1318 			 * will be ignored.  We also return here to
1319 			 * cope with the fact that the Thinkpads keep
1320 			 * sending a SUSPEND event until something else
1321 			 * happens!
1322 			 */
1323 			if (ignore_sys_suspend)
1324 				return;
1325 			ignore_sys_suspend = 1;
1326 			queue_event(event, NULL);
1327 			if (suspends_pending <= 0)
1328 				(void) suspend(1);
1329 			break;
1330 
1331 		case APM_NORMAL_RESUME:
1332 		case APM_CRITICAL_RESUME:
1333 		case APM_STANDBY_RESUME:
1334 			ignore_sys_suspend = 0;
1335 			last_resume = jiffies;
1336 			ignore_bounce = 1;
1337 			if ((event != APM_NORMAL_RESUME)
1338 			    || (ignore_normal_resume == 0)) {
1339 				device_resume();
1340 				pm_send_all(PM_RESUME, (void *)0);
1341 				queue_event(event, NULL);
1342 			}
1343 			ignore_normal_resume = 0;
1344 			break;
1345 
1346 		case APM_CAPABILITY_CHANGE:
1347 		case APM_LOW_BATTERY:
1348 		case APM_POWER_STATUS_CHANGE:
1349 			queue_event(event, NULL);
1350 			/* If needed, notify drivers here */
1351 			break;
1352 
1353 		case APM_UPDATE_TIME:
1354 			break;
1355 
1356 		case APM_CRITICAL_SUSPEND:
1357 			/*
1358 			 * We are not allowed to reject a critical suspend.
1359 			 */
1360 			(void)suspend(0);
1361 			break;
1362 		}
1363 	}
1364 }
1365 
1366 static void apm_event_handler(void)
1367 {
1368 	static int pending_count = 4;
1369 	int err;
1370 
1371 	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1372 		if ((apm_info.connection_version > 0x100) &&
1373 		    (pending_count-- <= 0)) {
1374 			pending_count = 4;
1375 			if (debug)
1376 				printk(KERN_DEBUG "apm: setting state busy\n");
1377 			err = set_system_power_state(APM_STATE_BUSY);
1378 			if (err)
1379 				apm_error("busy", err);
1380 		}
1381 	} else
1382 		pending_count = 4;
1383 	check_events();
1384 }
1385 
1386 /*
1387  * This is the APM thread main loop.
1388  */
1389 
1390 static void apm_mainloop(void)
1391 {
1392 	DECLARE_WAITQUEUE(wait, current);
1393 
1394 	add_wait_queue(&apm_waitqueue, &wait);
1395 	set_current_state(TASK_INTERRUPTIBLE);
1396 	for (;;) {
1397 		schedule_timeout(APM_CHECK_TIMEOUT);
1398 		if (kthread_should_stop())
1399 			break;
1400 		/*
1401 		 * Ok, check all events, check for idle (and mark us sleeping
1402 		 * so as not to count towards the load average)..
1403 		 */
1404 		set_current_state(TASK_INTERRUPTIBLE);
1405 		apm_event_handler();
1406 	}
1407 	remove_wait_queue(&apm_waitqueue, &wait);
1408 }
1409 
1410 static int check_apm_user(struct apm_user *as, const char *func)
1411 {
1412 	if ((as == NULL) || (as->magic != APM_BIOS_MAGIC)) {
1413 		printk(KERN_ERR "apm: %s passed bad filp\n", func);
1414 		return 1;
1415 	}
1416 	return 0;
1417 }
1418 
1419 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1420 {
1421 	struct apm_user *as;
1422 	int i;
1423 	apm_event_t event;
1424 
1425 	as = fp->private_data;
1426 	if (check_apm_user(as, "read"))
1427 		return -EIO;
1428 	if ((int)count < sizeof(apm_event_t))
1429 		return -EINVAL;
1430 	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1431 		return -EAGAIN;
1432 	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1433 	i = count;
1434 	while ((i >= sizeof(event)) && !queue_empty(as)) {
1435 		event = get_queued_event(as);
1436 		if (copy_to_user(buf, &event, sizeof(event))) {
1437 			if (i < count)
1438 				break;
1439 			return -EFAULT;
1440 		}
1441 		switch (event) {
1442 		case APM_SYS_SUSPEND:
1443 		case APM_USER_SUSPEND:
1444 			as->suspends_read++;
1445 			break;
1446 
1447 		case APM_SYS_STANDBY:
1448 		case APM_USER_STANDBY:
1449 			as->standbys_read++;
1450 			break;
1451 		}
1452 		buf += sizeof(event);
1453 		i -= sizeof(event);
1454 	}
1455 	if (i < count)
1456 		return count - i;
1457 	if (signal_pending(current))
1458 		return -ERESTARTSYS;
1459 	return 0;
1460 }
1461 
1462 static unsigned int do_poll(struct file *fp, poll_table *wait)
1463 {
1464 	struct apm_user *as;
1465 
1466 	as = fp->private_data;
1467 	if (check_apm_user(as, "poll"))
1468 		return 0;
1469 	poll_wait(fp, &apm_waitqueue, wait);
1470 	if (!queue_empty(as))
1471 		return POLLIN | POLLRDNORM;
1472 	return 0;
1473 }
1474 
1475 static int do_ioctl(struct inode *inode, struct file *filp,
1476 		    u_int cmd, u_long arg)
1477 {
1478 	struct apm_user *as;
1479 
1480 	as = filp->private_data;
1481 	if (check_apm_user(as, "ioctl"))
1482 		return -EIO;
1483 	if ((!as->suser) || (!as->writer))
1484 		return -EPERM;
1485 	switch (cmd) {
1486 	case APM_IOC_STANDBY:
1487 		if (as->standbys_read > 0) {
1488 			as->standbys_read--;
1489 			as->standbys_pending--;
1490 			standbys_pending--;
1491 		} else
1492 			queue_event(APM_USER_STANDBY, as);
1493 		if (standbys_pending <= 0)
1494 			standby();
1495 		break;
1496 	case APM_IOC_SUSPEND:
1497 		if (as->suspends_read > 0) {
1498 			as->suspends_read--;
1499 			as->suspends_pending--;
1500 			suspends_pending--;
1501 		} else
1502 			queue_event(APM_USER_SUSPEND, as);
1503 		if (suspends_pending <= 0) {
1504 			return suspend(1);
1505 		} else {
1506 			as->suspend_wait = 1;
1507 			wait_event_interruptible(apm_suspend_waitqueue,
1508 					as->suspend_wait == 0);
1509 			return as->suspend_result;
1510 		}
1511 		break;
1512 	default:
1513 		return -EINVAL;
1514 	}
1515 	return 0;
1516 }
1517 
1518 static int do_release(struct inode *inode, struct file *filp)
1519 {
1520 	struct apm_user *as;
1521 
1522 	as = filp->private_data;
1523 	if (check_apm_user(as, "release"))
1524 		return 0;
1525 	filp->private_data = NULL;
1526 	if (as->standbys_pending > 0) {
1527 		standbys_pending -= as->standbys_pending;
1528 		if (standbys_pending <= 0)
1529 			standby();
1530 	}
1531 	if (as->suspends_pending > 0) {
1532 		suspends_pending -= as->suspends_pending;
1533 		if (suspends_pending <= 0)
1534 			(void) suspend(1);
1535 	}
1536 	spin_lock(&user_list_lock);
1537 	if (user_list == as)
1538 		user_list = as->next;
1539 	else {
1540 		struct apm_user *as1;
1541 
1542 		for (as1 = user_list;
1543 		     (as1 != NULL) && (as1->next != as);
1544 		     as1 = as1->next)
1545 			;
1546 		if (as1 == NULL)
1547 			printk(KERN_ERR "apm: filp not in user list\n");
1548 		else
1549 			as1->next = as->next;
1550 	}
1551 	spin_unlock(&user_list_lock);
1552 	kfree(as);
1553 	return 0;
1554 }
1555 
1556 static int do_open(struct inode *inode, struct file *filp)
1557 {
1558 	struct apm_user *as;
1559 
1560 	as = kmalloc(sizeof(*as), GFP_KERNEL);
1561 	if (as == NULL) {
1562 		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1563 		       sizeof(*as));
1564 		return -ENOMEM;
1565 	}
1566 	as->magic = APM_BIOS_MAGIC;
1567 	as->event_tail = as->event_head = 0;
1568 	as->suspends_pending = as->standbys_pending = 0;
1569 	as->suspends_read = as->standbys_read = 0;
1570 	/*
1571 	 * XXX - this is a tiny bit broken, when we consider BSD
1572 	 * process accounting. If the device is opened by root, we
1573 	 * instantly flag that we used superuser privs. Who knows,
1574 	 * we might close the device immediately without doing a
1575 	 * privileged operation -- cevans
1576 	 */
1577 	as->suser = capable(CAP_SYS_ADMIN);
1578 	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1579 	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1580 	spin_lock(&user_list_lock);
1581 	as->next = user_list;
1582 	user_list = as;
1583 	spin_unlock(&user_list_lock);
1584 	filp->private_data = as;
1585 	return 0;
1586 }
1587 
1588 static int proc_apm_show(struct seq_file *m, void *v)
1589 {
1590 	unsigned short	bx;
1591 	unsigned short	cx;
1592 	unsigned short	dx;
1593 	int		error;
1594 	unsigned short  ac_line_status = 0xff;
1595 	unsigned short  battery_status = 0xff;
1596 	unsigned short  battery_flag   = 0xff;
1597 	int		percentage     = -1;
1598 	int             time_units     = -1;
1599 	char            *units         = "?";
1600 
1601 	if ((num_online_cpus() == 1) &&
1602 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1603 		ac_line_status = (bx >> 8) & 0xff;
1604 		battery_status = bx & 0xff;
1605 		if ((cx & 0xff) != 0xff)
1606 			percentage = cx & 0xff;
1607 
1608 		if (apm_info.connection_version > 0x100) {
1609 			battery_flag = (cx >> 8) & 0xff;
1610 			if (dx != 0xffff) {
1611 				units = (dx & 0x8000) ? "min" : "sec";
1612 				time_units = dx & 0x7fff;
1613 			}
1614 		}
1615 	}
1616 	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1617 	   from the Get Power Status (0x0a) call unless otherwise noted.
1618 
1619 	   0) Linux driver version (this will change if format changes)
1620 	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1621 	   2) APM flags from APM Installation Check (0x00):
1622 	      bit 0: APM_16_BIT_SUPPORT
1623 	      bit 1: APM_32_BIT_SUPPORT
1624 	      bit 2: APM_IDLE_SLOWS_CLOCK
1625 	      bit 3: APM_BIOS_DISABLED
1626 	      bit 4: APM_BIOS_DISENGAGED
1627 	   3) AC line status
1628 	      0x00: Off-line
1629 	      0x01: On-line
1630 	      0x02: On backup power (BIOS >= 1.1 only)
1631 	      0xff: Unknown
1632 	   4) Battery status
1633 	      0x00: High
1634 	      0x01: Low
1635 	      0x02: Critical
1636 	      0x03: Charging
1637 	      0x04: Selected battery not present (BIOS >= 1.2 only)
1638 	      0xff: Unknown
1639 	   5) Battery flag
1640 	      bit 0: High
1641 	      bit 1: Low
1642 	      bit 2: Critical
1643 	      bit 3: Charging
1644 	      bit 7: No system battery
1645 	      0xff: Unknown
1646 	   6) Remaining battery life (percentage of charge):
1647 	      0-100: valid
1648 	      -1: Unknown
1649 	   7) Remaining battery life (time units):
1650 	      Number of remaining minutes or seconds
1651 	      -1: Unknown
1652 	   8) min = minutes; sec = seconds */
1653 
1654 	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1655 		   driver_version,
1656 		   (apm_info.bios.version >> 8) & 0xff,
1657 		   apm_info.bios.version & 0xff,
1658 		   apm_info.bios.flags,
1659 		   ac_line_status,
1660 		   battery_status,
1661 		   battery_flag,
1662 		   percentage,
1663 		   time_units,
1664 		   units);
1665 	return 0;
1666 }
1667 
1668 static int proc_apm_open(struct inode *inode, struct file *file)
1669 {
1670 	return single_open(file, proc_apm_show, NULL);
1671 }
1672 
1673 static const struct file_operations apm_file_ops = {
1674 	.owner		= THIS_MODULE,
1675 	.open		= proc_apm_open,
1676 	.read		= seq_read,
1677 	.llseek		= seq_lseek,
1678 	.release	= single_release,
1679 };
1680 
1681 static int apm(void *unused)
1682 {
1683 	unsigned short	bx;
1684 	unsigned short	cx;
1685 	unsigned short	dx;
1686 	int		error;
1687 	char 		*power_stat;
1688 	char 		*bat_stat;
1689 
1690 #ifdef CONFIG_SMP
1691 	/* 2002/08/01 - WT
1692 	 * This is to avoid random crashes at boot time during initialization
1693 	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1694 	 * Some bioses don't like being called from CPU != 0.
1695 	 * Method suggested by Ingo Molnar.
1696 	 */
1697 	set_cpus_allowed(current, cpumask_of_cpu(0));
1698 	BUG_ON(smp_processor_id() != 0);
1699 #endif
1700 
1701 	if (apm_info.connection_version == 0) {
1702 		apm_info.connection_version = apm_info.bios.version;
1703 		if (apm_info.connection_version > 0x100) {
1704 			/*
1705 			 * We only support BIOSs up to version 1.2
1706 			 */
1707 			if (apm_info.connection_version > 0x0102)
1708 				apm_info.connection_version = 0x0102;
1709 			error = apm_driver_version(&apm_info.connection_version);
1710 			if (error != APM_SUCCESS) {
1711 				apm_error("driver version", error);
1712 				/* Fall back to an APM 1.0 connection. */
1713 				apm_info.connection_version = 0x100;
1714 			}
1715 		}
1716 	}
1717 
1718 	if (debug)
1719 		printk(KERN_INFO "apm: Connection version %d.%d\n",
1720 			(apm_info.connection_version >> 8) & 0xff,
1721 			apm_info.connection_version & 0xff);
1722 
1723 #ifdef CONFIG_APM_DO_ENABLE
1724 	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1725 		/*
1726 		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1727 		 * is booted with PM disabled but not in the docking station.
1728 		 * Unfortunate ...
1729 		 */
1730 		error = apm_enable_power_management(1);
1731 		if (error) {
1732 			apm_error("enable power management", error);
1733 			return -1;
1734 		}
1735 	}
1736 #endif
1737 
1738 	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1739 	    && (apm_info.connection_version > 0x0100)) {
1740 		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1741 		if (error) {
1742 			apm_error("engage power management", error);
1743 			return -1;
1744 		}
1745 	}
1746 
1747 	if (debug && (num_online_cpus() == 1 || smp)) {
1748 		error = apm_get_power_status(&bx, &cx, &dx);
1749 		if (error)
1750 			printk(KERN_INFO "apm: power status not available\n");
1751 		else {
1752 			switch ((bx >> 8) & 0xff) {
1753 			case 0:
1754 				power_stat = "off line";
1755 				break;
1756 			case 1:
1757 				power_stat = "on line";
1758 				break;
1759 			case 2:
1760 				power_stat = "on backup power";
1761 				break;
1762 			default:
1763 				power_stat = "unknown";
1764 				break;
1765 			}
1766 			switch (bx & 0xff) {
1767 			case 0:
1768 				bat_stat = "high";
1769 				break;
1770 			case 1:
1771 				bat_stat = "low";
1772 				break;
1773 			case 2:
1774 				bat_stat = "critical";
1775 				break;
1776 			case 3:
1777 				bat_stat = "charging";
1778 				break;
1779 			default:
1780 				bat_stat = "unknown";
1781 				break;
1782 			}
1783 			printk(KERN_INFO
1784 			       "apm: AC %s, battery status %s, battery life ",
1785 			       power_stat, bat_stat);
1786 			if ((cx & 0xff) == 0xff)
1787 				printk("unknown\n");
1788 			else
1789 				printk("%d%%\n", cx & 0xff);
1790 			if (apm_info.connection_version > 0x100) {
1791 				printk(KERN_INFO
1792 				       "apm: battery flag 0x%02x, battery life ",
1793 				       (cx >> 8) & 0xff);
1794 				if (dx == 0xffff)
1795 					printk("unknown\n");
1796 				else
1797 					printk("%d %s\n", dx & 0x7fff,
1798 					       (dx & 0x8000) ?
1799 					       "minutes" : "seconds");
1800 			}
1801 		}
1802 	}
1803 
1804 	/* Install our power off handler.. */
1805 	if (power_off)
1806 		pm_power_off = apm_power_off;
1807 
1808 	if (num_online_cpus() == 1 || smp) {
1809 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1810 		console_blank_hook = apm_console_blank;
1811 #endif
1812 		apm_mainloop();
1813 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1814 		console_blank_hook = NULL;
1815 #endif
1816 	}
1817 
1818 	return 0;
1819 }
1820 
1821 #ifndef MODULE
1822 static int __init apm_setup(char *str)
1823 {
1824 	int invert;
1825 
1826 	while ((str != NULL) && (*str != '\0')) {
1827 		if (strncmp(str, "off", 3) == 0)
1828 			apm_disabled = 1;
1829 		if (strncmp(str, "on", 2) == 0)
1830 			apm_disabled = 0;
1831 		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1832 		    (strncmp(str, "bounce_interval=", 16) == 0))
1833 			bounce_interval = simple_strtol(str + 16, NULL, 0);
1834 		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1835 		    (strncmp(str, "idle_threshold=", 15) == 0))
1836 			idle_threshold = simple_strtol(str + 15, NULL, 0);
1837 		if ((strncmp(str, "idle-period=", 12) == 0) ||
1838 		    (strncmp(str, "idle_period=", 12) == 0))
1839 			idle_period = simple_strtol(str + 12, NULL, 0);
1840 		invert = (strncmp(str, "no-", 3) == 0) ||
1841 			(strncmp(str, "no_", 3) == 0);
1842 		if (invert)
1843 			str += 3;
1844 		if (strncmp(str, "debug", 5) == 0)
1845 			debug = !invert;
1846 		if ((strncmp(str, "power-off", 9) == 0) ||
1847 		    (strncmp(str, "power_off", 9) == 0))
1848 			power_off = !invert;
1849 		if (strncmp(str, "smp", 3) == 0) {
1850 			smp = !invert;
1851 			idle_threshold = 100;
1852 		}
1853 		if ((strncmp(str, "allow-ints", 10) == 0) ||
1854 		    (strncmp(str, "allow_ints", 10) == 0))
1855 			apm_info.allow_ints = !invert;
1856 		if ((strncmp(str, "broken-psr", 10) == 0) ||
1857 		    (strncmp(str, "broken_psr", 10) == 0))
1858 			apm_info.get_power_status_broken = !invert;
1859 		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1860 		    (strncmp(str, "realmode_power_off", 18) == 0))
1861 			apm_info.realmode_power_off = !invert;
1862 		str = strchr(str, ',');
1863 		if (str != NULL)
1864 			str += strspn(str, ", \t");
1865 	}
1866 	return 1;
1867 }
1868 
1869 __setup("apm=", apm_setup);
1870 #endif
1871 
1872 static const struct file_operations apm_bios_fops = {
1873 	.owner		= THIS_MODULE,
1874 	.read		= do_read,
1875 	.poll		= do_poll,
1876 	.ioctl		= do_ioctl,
1877 	.open		= do_open,
1878 	.release	= do_release,
1879 };
1880 
1881 static struct miscdevice apm_device = {
1882 	APM_MINOR_DEV,
1883 	"apm_bios",
1884 	&apm_bios_fops
1885 };
1886 
1887 
1888 /* Simple "print if true" callback */
1889 static int __init print_if_true(const struct dmi_system_id *d)
1890 {
1891 	printk("%s\n", d->ident);
1892 	return 0;
1893 }
1894 
1895 /*
1896  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1897  * disabled before the suspend. Linux used to get terribly confused by that.
1898  */
1899 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1900 {
1901 	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1902 	       "workaround hopefully not needed.\n", d->ident);
1903 	return 0;
1904 }
1905 
1906 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1907 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1908 {
1909 	if (apm_info.realmode_power_off == 0) {
1910 		apm_info.realmode_power_off = 1;
1911 		printk(KERN_INFO "%s bios detected. "
1912 		       "Using realmode poweroff only.\n", d->ident);
1913 	}
1914 	return 0;
1915 }
1916 
1917 /* Some laptops require interrupts to be enabled during APM calls */
1918 static int __init set_apm_ints(const struct dmi_system_id *d)
1919 {
1920 	if (apm_info.allow_ints == 0) {
1921 		apm_info.allow_ints = 1;
1922 		printk(KERN_INFO "%s machine detected. "
1923 		       "Enabling interrupts during APM calls.\n", d->ident);
1924 	}
1925 	return 0;
1926 }
1927 
1928 /* Some APM bioses corrupt memory or just plain do not work */
1929 static int __init apm_is_horked(const struct dmi_system_id *d)
1930 {
1931 	if (apm_info.disabled == 0) {
1932 		apm_info.disabled = 1;
1933 		printk(KERN_INFO "%s machine detected. "
1934 		       "Disabling APM.\n", d->ident);
1935 	}
1936 	return 0;
1937 }
1938 
1939 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1940 {
1941 	if (apm_info.disabled == 0) {
1942 		apm_info.disabled = 1;
1943 		printk(KERN_INFO "%s machine detected. "
1944 		       "Disabling APM.\n", d->ident);
1945 		printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
1946 		printk(KERN_INFO "download from support.intel.com \n");
1947 	}
1948 	return 0;
1949 }
1950 
1951 /* Some APM bioses hang on APM idle calls */
1952 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1953 {
1954 	if (apm_info.forbid_idle == 0) {
1955 		apm_info.forbid_idle = 1;
1956 		printk(KERN_INFO "%s machine detected. "
1957 		       "Disabling APM idle calls.\n", d->ident);
1958 	}
1959 	return 0;
1960 }
1961 
1962 /*
1963  *  Check for clue free BIOS implementations who use
1964  *  the following QA technique
1965  *
1966  *      [ Write BIOS Code ]<------
1967  *               |                ^
1968  *      < Does it Compile >----N--
1969  *               |Y               ^
1970  *	< Does it Boot Win98 >-N--
1971  *               |Y
1972  *           [Ship It]
1973  *
1974  *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
1975  *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
1976  */
1977 static int __init broken_apm_power(const struct dmi_system_id *d)
1978 {
1979 	apm_info.get_power_status_broken = 1;
1980 	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
1981 	       "disabling power status reporting.\n");
1982 	return 0;
1983 }
1984 
1985 /*
1986  * This bios swaps the APM minute reporting bytes over (Many sony laptops
1987  * have this problem).
1988  */
1989 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
1990 {
1991 	apm_info.get_power_status_swabinminutes = 1;
1992 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
1993 	       "in minutes and wrong byte order.\n");
1994 	return 0;
1995 }
1996 
1997 static struct dmi_system_id __initdata apm_dmi_table[] = {
1998 	{
1999 		print_if_true,
2000 		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2001 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2002 			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2003 	},
2004 	{	/* Handle problems with APM on the C600 */
2005 		broken_ps2_resume, "Dell Latitude C600",
2006 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2007 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2008 	},
2009 	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2010 		set_apm_ints, "Dell Latitude",
2011 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2012 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2013 	},
2014 	{	/* APM crashes */
2015 		apm_is_horked, "Dell Inspiron 2500",
2016 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2017 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2018 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2019 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2020 	},
2021 	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2022 		set_apm_ints, "Dell Inspiron", {
2023 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2024 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2025 	},
2026 	{	/* Handle problems with APM on Inspiron 5000e */
2027 		broken_apm_power, "Dell Inspiron 5000e",
2028 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2029 			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2030 			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2031 	},
2032 	{	/* Handle problems with APM on Inspiron 2500 */
2033 		broken_apm_power, "Dell Inspiron 2500",
2034 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2035 			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2036 			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2037 	},
2038 	{	/* APM crashes */
2039 		apm_is_horked, "Dell Dimension 4100",
2040 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2041 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2042 			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2043 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2044 	},
2045 	{	/* Allow interrupts during suspend on Compaq Laptops*/
2046 		set_apm_ints, "Compaq 12XL125",
2047 		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2048 			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2049 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2050 			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2051 	},
2052 	{	/* Allow interrupts during APM or the clock goes slow */
2053 		set_apm_ints, "ASUSTeK",
2054 		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2055 			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2056 	},
2057 	{	/* APM blows on shutdown */
2058 		apm_is_horked, "ABIT KX7-333[R]",
2059 		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2060 			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2061 	},
2062 	{	/* APM crashes */
2063 		apm_is_horked, "Trigem Delhi3",
2064 		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2065 			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2066 	},
2067 	{	/* APM crashes */
2068 		apm_is_horked, "Fujitsu-Siemens",
2069 		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2070 			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2071 	},
2072 	{	/* APM crashes */
2073 		apm_is_horked_d850md, "Intel D850MD",
2074 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2075 			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2076 	},
2077 	{	/* APM crashes */
2078 		apm_is_horked, "Intel D810EMO",
2079 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2080 			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2081 	},
2082 	{	/* APM crashes */
2083 		apm_is_horked, "Dell XPS-Z",
2084 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2085 			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2086 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2087 	},
2088 	{	/* APM crashes */
2089 		apm_is_horked, "Sharp PC-PJ/AX",
2090 		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2091 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2092 			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2093 			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2094 	},
2095 	{	/* APM crashes */
2096 		apm_is_horked, "Dell Inspiron 2500",
2097 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2098 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2099 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2100 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2101 	},
2102 	{	/* APM idle hangs */
2103 		apm_likes_to_melt, "Jabil AMD",
2104 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2105 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2106 	},
2107 	{	/* APM idle hangs */
2108 		apm_likes_to_melt, "AMI Bios",
2109 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2110 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2111 	},
2112 	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2113 		swab_apm_power_in_minutes, "Sony VAIO",
2114 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2115 			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2116 			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2117 	},
2118 	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2119 		swab_apm_power_in_minutes, "Sony VAIO",
2120 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2121 			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2122 			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2123 	},
2124 	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2125 		swab_apm_power_in_minutes, "Sony VAIO",
2126 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2127 			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2128 			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2129 	},
2130 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2131 		swab_apm_power_in_minutes, "Sony VAIO",
2132 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2133 			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2134 			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2135 	},
2136 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2137 		swab_apm_power_in_minutes, "Sony VAIO",
2138 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2139 			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2140 			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2141 	},
2142 	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2143 		swab_apm_power_in_minutes, "Sony VAIO",
2144 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2145 			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2146 			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2147 	},
2148 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2149 		swab_apm_power_in_minutes, "Sony VAIO",
2150 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2151 			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2152 			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2153 	},
2154 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2155 		swab_apm_power_in_minutes, "Sony VAIO",
2156 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2157 			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2158 			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2159 	},
2160 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2161 		swab_apm_power_in_minutes, "Sony VAIO",
2162 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2163 			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2164 			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2165 	},
2166 	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2167 		swab_apm_power_in_minutes, "Sony VAIO",
2168 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2169 			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2170 			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2171 	},
2172 
2173 	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2174 		swab_apm_power_in_minutes, "Sony VAIO",
2175 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2176 			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2177 			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2178 	},
2179 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2180 		swab_apm_power_in_minutes, "Sony VAIO",
2181 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2182 			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2183 			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2184 	},
2185 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2186 		swab_apm_power_in_minutes, "Sony VAIO",
2187 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2188 			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2189 			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2190 	},
2191 	{	/* broken PM poweroff bios */
2192 		set_realmode_power_off, "Award Software v4.60 PGMA",
2193 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2194 			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2195 			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2196 	},
2197 
2198 	/* Generic per vendor APM settings  */
2199 
2200 	{	/* Allow interrupts during suspend on IBM laptops */
2201 		set_apm_ints, "IBM",
2202 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2203 	},
2204 
2205 	{ }
2206 };
2207 
2208 /*
2209  * Just start the APM thread. We do NOT want to do APM BIOS
2210  * calls from anything but the APM thread, if for no other reason
2211  * than the fact that we don't trust the APM BIOS. This way,
2212  * most common APM BIOS problems that lead to protection errors
2213  * etc will have at least some level of being contained...
2214  *
2215  * In short, if something bad happens, at least we have a choice
2216  * of just killing the apm thread..
2217  */
2218 static int __init apm_init(void)
2219 {
2220 	struct desc_struct *gdt;
2221 	int err;
2222 
2223 	dmi_check_system(apm_dmi_table);
2224 
2225 	if (apm_info.bios.version == 0 || paravirt_enabled()) {
2226 		printk(KERN_INFO "apm: BIOS not found.\n");
2227 		return -ENODEV;
2228 	}
2229 	printk(KERN_INFO
2230 	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2231 	       ((apm_info.bios.version >> 8) & 0xff),
2232 	       (apm_info.bios.version & 0xff),
2233 	       apm_info.bios.flags,
2234 	       driver_version);
2235 	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2236 		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2237 		return -ENODEV;
2238 	}
2239 
2240 	if (allow_ints)
2241 		apm_info.allow_ints = 1;
2242 	if (broken_psr)
2243 		apm_info.get_power_status_broken = 1;
2244 	if (realmode_power_off)
2245 		apm_info.realmode_power_off = 1;
2246 	/* User can override, but default is to trust DMI */
2247 	if (apm_disabled != -1)
2248 		apm_info.disabled = apm_disabled;
2249 
2250 	/*
2251 	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2252 	 * but is reportedly a 1.0 BIOS.
2253 	 */
2254 	if (apm_info.bios.version == 0x001)
2255 		apm_info.bios.version = 0x100;
2256 
2257 	/* BIOS < 1.2 doesn't set cseg_16_len */
2258 	if (apm_info.bios.version < 0x102)
2259 		apm_info.bios.cseg_16_len = 0; /* 64k */
2260 
2261 	if (debug) {
2262 		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2263 			apm_info.bios.cseg, apm_info.bios.offset,
2264 			apm_info.bios.cseg_16, apm_info.bios.dseg);
2265 		if (apm_info.bios.version > 0x100)
2266 			printk(" cseg len %x, dseg len %x",
2267 				apm_info.bios.cseg_len,
2268 				apm_info.bios.dseg_len);
2269 		if (apm_info.bios.version > 0x101)
2270 			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2271 		printk("\n");
2272 	}
2273 
2274 	if (apm_info.disabled) {
2275 		printk(KERN_NOTICE "apm: disabled on user request.\n");
2276 		return -ENODEV;
2277 	}
2278 	if ((num_online_cpus() > 1) && !power_off && !smp) {
2279 		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2280 		apm_info.disabled = 1;
2281 		return -ENODEV;
2282 	}
2283 	if (pm_flags & PM_ACPI) {
2284 		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2285 		apm_info.disabled = 1;
2286 		return -ENODEV;
2287 	}
2288 	pm_flags |= PM_APM;
2289 
2290 	/*
2291 	 * Set up a segment that references the real mode segment 0x40
2292 	 * that extends up to the end of page zero (that we have reserved).
2293 	 * This is for buggy BIOS's that refer to (real mode) segment 0x40
2294 	 * even though they are called in protected mode.
2295 	 */
2296 	set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2297 	_set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2298 
2299 	/*
2300 	 * Set up the long jump entry point to the APM BIOS, which is called
2301 	 * from inline assembly.
2302 	 */
2303 	apm_bios_entry.offset = apm_info.bios.offset;
2304 	apm_bios_entry.segment = APM_CS;
2305 
2306 	/*
2307 	 * The APM 1.1 BIOS is supposed to provide limit information that it
2308 	 * recognizes.  Many machines do this correctly, but many others do
2309 	 * not restrict themselves to their claimed limit.  When this happens,
2310 	 * they will cause a segmentation violation in the kernel at boot time.
2311 	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2312 	 *
2313 	 * Note we only set APM segments on CPU zero, since we pin the APM
2314 	 * code to that CPU.
2315 	 */
2316 	gdt = get_cpu_gdt_table(0);
2317 	set_base(gdt[APM_CS >> 3],
2318 		 __va((unsigned long)apm_info.bios.cseg << 4));
2319 	set_base(gdt[APM_CS_16 >> 3],
2320 		 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2321 	set_base(gdt[APM_DS >> 3],
2322 		 __va((unsigned long)apm_info.bios.dseg << 4));
2323 
2324 	proc_create("apm", 0, NULL, &apm_file_ops);
2325 
2326 	kapmd_task = kthread_create(apm, NULL, "kapmd");
2327 	if (IS_ERR(kapmd_task)) {
2328 		printk(KERN_ERR "apm: disabled - Unable to start kernel "
2329 				"thread.\n");
2330 		err = PTR_ERR(kapmd_task);
2331 		kapmd_task = NULL;
2332 		remove_proc_entry("apm", NULL);
2333 		return err;
2334 	}
2335 	wake_up_process(kapmd_task);
2336 
2337 	if (num_online_cpus() > 1 && !smp) {
2338 		printk(KERN_NOTICE
2339 		       "apm: disabled - APM is not SMP safe (power off active).\n");
2340 		return 0;
2341 	}
2342 
2343 	/*
2344 	 * Note we don't actually care if the misc_device cannot be registered.
2345 	 * this driver can do its job without it, even if userspace can't
2346 	 * control it.  just log the error
2347 	 */
2348 	if (misc_register(&apm_device))
2349 		printk(KERN_WARNING "apm: Could not register misc device.\n");
2350 
2351 	if (HZ != 100)
2352 		idle_period = (idle_period * HZ) / 100;
2353 	if (idle_threshold < 100) {
2354 		original_pm_idle = pm_idle;
2355 		pm_idle  = apm_cpu_idle;
2356 		set_pm_idle = 1;
2357 	}
2358 
2359 	return 0;
2360 }
2361 
2362 static void __exit apm_exit(void)
2363 {
2364 	int error;
2365 
2366 	if (set_pm_idle) {
2367 		pm_idle = original_pm_idle;
2368 		/*
2369 		 * We are about to unload the current idle thread pm callback
2370 		 * (pm_idle), Wait for all processors to update cached/local
2371 		 * copies of pm_idle before proceeding.
2372 		 */
2373 		cpu_idle_wait();
2374 	}
2375 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2376 	    && (apm_info.connection_version > 0x0100)) {
2377 		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2378 		if (error)
2379 			apm_error("disengage power management", error);
2380 	}
2381 	misc_deregister(&apm_device);
2382 	remove_proc_entry("apm", NULL);
2383 	if (power_off)
2384 		pm_power_off = NULL;
2385 	if (kapmd_task) {
2386 		kthread_stop(kapmd_task);
2387 		kapmd_task = NULL;
2388 	}
2389 	pm_flags &= ~PM_APM;
2390 }
2391 
2392 module_init(apm_init);
2393 module_exit(apm_exit);
2394 
2395 MODULE_AUTHOR("Stephen Rothwell");
2396 MODULE_DESCRIPTION("Advanced Power Management");
2397 MODULE_LICENSE("GPL");
2398 module_param(debug, bool, 0644);
2399 MODULE_PARM_DESC(debug, "Enable debug mode");
2400 module_param(power_off, bool, 0444);
2401 MODULE_PARM_DESC(power_off, "Enable power off");
2402 module_param(bounce_interval, int, 0444);
2403 MODULE_PARM_DESC(bounce_interval,
2404 		"Set the number of ticks to ignore suspend bounces");
2405 module_param(allow_ints, bool, 0444);
2406 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2407 module_param(broken_psr, bool, 0444);
2408 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2409 module_param(realmode_power_off, bool, 0444);
2410 MODULE_PARM_DESC(realmode_power_off,
2411 		"Switch to real mode before powering off");
2412 module_param(idle_threshold, int, 0444);
2413 MODULE_PARM_DESC(idle_threshold,
2414 	"System idle percentage above which to make APM BIOS idle calls");
2415 module_param(idle_period, int, 0444);
2416 MODULE_PARM_DESC(idle_period,
2417 	"Period (in sec/100) over which to caculate the idle percentage");
2418 module_param(smp, bool, 0444);
2419 MODULE_PARM_DESC(smp,
2420 	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2421 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2422