xref: /linux/arch/x86/kernel/apm_32.c (revision c5aec4c76af1a2d89ee2f2d4d5463b2ad2d85de5)
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 compiler/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@ucw.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@lxorguk.ukuu.org.uk>).
164  *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165  *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
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 from
193  * http://www.microsoft.com/whdc/archive/amp_12.mspx  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 #define pr_fmt(fmt) "apm: " fmt
205 
206 #include <linux/module.h>
207 
208 #include <linux/poll.h>
209 #include <linux/types.h>
210 #include <linux/stddef.h>
211 #include <linux/timer.h>
212 #include <linux/fcntl.h>
213 #include <linux/slab.h>
214 #include <linux/stat.h>
215 #include <linux/proc_fs.h>
216 #include <linux/seq_file.h>
217 #include <linux/miscdevice.h>
218 #include <linux/apm_bios.h>
219 #include <linux/init.h>
220 #include <linux/time.h>
221 #include <linux/sched.h>
222 #include <linux/pm.h>
223 #include <linux/capability.h>
224 #include <linux/device.h>
225 #include <linux/kernel.h>
226 #include <linux/freezer.h>
227 #include <linux/smp.h>
228 #include <linux/dmi.h>
229 #include <linux/suspend.h>
230 #include <linux/kthread.h>
231 #include <linux/jiffies.h>
232 #include <linux/acpi.h>
233 #include <linux/syscore_ops.h>
234 #include <linux/i8253.h>
235 #include <linux/cpuidle.h>
236 
237 #include <asm/uaccess.h>
238 #include <asm/desc.h>
239 #include <asm/olpc.h>
240 #include <asm/paravirt.h>
241 #include <asm/reboot.h>
242 
243 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
244 extern int (*console_blank_hook)(int);
245 #endif
246 
247 /*
248  * The apm_bios device is one of the misc char devices.
249  * This is its minor number.
250  */
251 #define	APM_MINOR_DEV	134
252 
253 /*
254  * Various options can be changed at boot time as follows:
255  * (We allow underscores for compatibility with the modules code)
256  *	apm=on/off			enable/disable APM
257  *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
258  *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
259  *	    [no-]realmode[-_]power[-_]off	switch to real mode before
260  *	    					powering off
261  *	    [no-]debug			log some debugging messages
262  *	    [no-]power[-_]off		power off on shutdown
263  *	    [no-]smp			Use apm even on an SMP box
264  *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
265  *	    				bounces
266  *          idle[-_]threshold=<n>       System idle percentage above which to
267  *                                      make APM BIOS idle calls. Set it to
268  *                                      100 to disable.
269  *          idle[-_]period=<n>          Period (in 1/100s of a second) over
270  *                                      which the idle percentage is
271  *                                      calculated.
272  */
273 
274 /* KNOWN PROBLEM MACHINES:
275  *
276  * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
277  *                         [Confirmed by TI representative]
278  * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
279  *                    [Confirmed by BIOS disassembly]
280  *                    [This may work now ...]
281  * P: Toshiba 1950S: battery life information only gets updated after resume
282  * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
283  * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
284  * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
285  * 	Neale Banks <neale@lowendale.com.au> December 2000
286  *
287  * Legend: U = unusable with APM patches
288  *         P = partially usable with APM patches
289  */
290 
291 /*
292  * Define as 1 to make the driver always call the APM BIOS busy
293  * routine even if the clock was not reported as slowed by the
294  * idle routine.  Otherwise, define as 0.
295  */
296 #define ALWAYS_CALL_BUSY   1
297 
298 /*
299  * Define to make the APM BIOS calls zero all data segment registers (so
300  * that an incorrect BIOS implementation will cause a kernel panic if it
301  * tries to write to arbitrary memory).
302  */
303 #define APM_ZERO_SEGS
304 
305 #include <asm/apm.h>
306 
307 /*
308  * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
309  * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
310  * David Chen <chen@ctpa04.mit.edu>
311  */
312 #undef INIT_TIMER_AFTER_SUSPEND
313 
314 #ifdef INIT_TIMER_AFTER_SUSPEND
315 #include <linux/timex.h>
316 #include <asm/io.h>
317 #include <linux/delay.h>
318 #endif
319 
320 /*
321  * Need to poll the APM BIOS every second
322  */
323 #define APM_CHECK_TIMEOUT	(HZ)
324 
325 /*
326  * Ignore suspend events for this amount of time after a resume
327  */
328 #define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
329 
330 /*
331  * Maximum number of events stored
332  */
333 #define APM_MAX_EVENTS		20
334 
335 /*
336  * The per-file APM data
337  */
338 struct apm_user {
339 	int		magic;
340 	struct apm_user *next;
341 	unsigned int	suser: 1;
342 	unsigned int	writer: 1;
343 	unsigned int	reader: 1;
344 	unsigned int	suspend_wait: 1;
345 	int		suspend_result;
346 	int		suspends_pending;
347 	int		standbys_pending;
348 	int		suspends_read;
349 	int		standbys_read;
350 	int		event_head;
351 	int		event_tail;
352 	apm_event_t	events[APM_MAX_EVENTS];
353 };
354 
355 /*
356  * The magic number in apm_user
357  */
358 #define APM_BIOS_MAGIC		0x4101
359 
360 /*
361  * idle percentage above which bios idle calls are done
362  */
363 #ifdef CONFIG_APM_CPU_IDLE
364 #define DEFAULT_IDLE_THRESHOLD	95
365 #else
366 #define DEFAULT_IDLE_THRESHOLD	100
367 #endif
368 #define DEFAULT_IDLE_PERIOD	(100 / 3)
369 
370 static int apm_cpu_idle(struct cpuidle_device *dev,
371 			struct cpuidle_driver *drv, int index);
372 
373 static struct cpuidle_driver apm_idle_driver = {
374 	.name = "apm_idle",
375 	.owner = THIS_MODULE,
376 	.states = {
377 		{ /* entry 0 is for polling */ },
378 		{ /* entry 1 is for APM idle */
379 			.name = "APM",
380 			.desc = "APM idle",
381 			.flags = CPUIDLE_FLAG_TIME_VALID,
382 			.exit_latency = 250,	/* WAG */
383 			.target_residency = 500,	/* WAG */
384 			.enter = &apm_cpu_idle
385 		},
386 	},
387 	.state_count = 2,
388 };
389 
390 static struct cpuidle_device apm_cpuidle_device;
391 
392 /*
393  * Local variables
394  */
395 __visible struct {
396 	unsigned long	offset;
397 	unsigned short	segment;
398 } apm_bios_entry;
399 static int clock_slowed;
400 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
401 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
402 static int suspends_pending;
403 static int standbys_pending;
404 static int ignore_sys_suspend;
405 static int ignore_normal_resume;
406 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
407 
408 static bool debug __read_mostly;
409 static bool smp __read_mostly;
410 static int apm_disabled = -1;
411 #ifdef CONFIG_SMP
412 static bool power_off;
413 #else
414 static bool power_off = 1;
415 #endif
416 static bool realmode_power_off;
417 #ifdef CONFIG_APM_ALLOW_INTS
418 static bool allow_ints = 1;
419 #else
420 static bool allow_ints;
421 #endif
422 static bool broken_psr;
423 
424 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
425 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
426 static struct apm_user *user_list;
427 static DEFINE_SPINLOCK(user_list_lock);
428 static DEFINE_MUTEX(apm_mutex);
429 
430 /*
431  * Set up a segment that references the real mode segment 0x40
432  * that extends up to the end of page zero (that we have reserved).
433  * This is for buggy BIOS's that refer to (real mode) segment 0x40
434  * even though they are called in protected mode.
435  */
436 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
437 			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
438 
439 static const char driver_version[] = "1.16ac";	/* no spaces */
440 
441 static struct task_struct *kapmd_task;
442 
443 /*
444  *	APM event names taken from the APM 1.2 specification. These are
445  *	the message codes that the BIOS uses to tell us about events
446  */
447 static const char * const apm_event_name[] = {
448 	"system standby",
449 	"system suspend",
450 	"normal resume",
451 	"critical resume",
452 	"low battery",
453 	"power status change",
454 	"update time",
455 	"critical suspend",
456 	"user standby",
457 	"user suspend",
458 	"system standby resume",
459 	"capabilities change"
460 };
461 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
462 
463 typedef struct lookup_t {
464 	int	key;
465 	char 	*msg;
466 } lookup_t;
467 
468 /*
469  *	The BIOS returns a set of standard error codes in AX when the
470  *	carry flag is set.
471  */
472 
473 static const lookup_t error_table[] = {
474 /* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
475 	{ APM_DISABLED,		"Power management disabled" },
476 	{ APM_CONNECTED,	"Real mode interface already connected" },
477 	{ APM_NOT_CONNECTED,	"Interface not connected" },
478 	{ APM_16_CONNECTED,	"16 bit interface already connected" },
479 /* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
480 	{ APM_32_CONNECTED,	"32 bit interface already connected" },
481 	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
482 	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
483 	{ APM_BAD_PARAM,	"Parameter out of range" },
484 	{ APM_NOT_ENGAGED,	"Interface not engaged" },
485 	{ APM_BAD_FUNCTION,     "Function not supported" },
486 	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
487 	{ APM_BAD_STATE,	"Unable to enter requested state" },
488 /* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
489 	{ APM_NO_ERROR,		"BIOS did not set a return code" },
490 	{ APM_NOT_PRESENT,	"No APM present" }
491 };
492 #define ERROR_COUNT	ARRAY_SIZE(error_table)
493 
494 /**
495  *	apm_error	-	display an APM error
496  *	@str: information string
497  *	@err: APM BIOS return code
498  *
499  *	Write a meaningful log entry to the kernel log in the event of
500  *	an APM error.  Note that this also handles (negative) kernel errors.
501  */
502 
503 static void apm_error(char *str, int err)
504 {
505 	int i;
506 
507 	for (i = 0; i < ERROR_COUNT; i++)
508 		if (error_table[i].key == err)
509 			break;
510 	if (i < ERROR_COUNT)
511 		pr_notice("%s: %s\n", str, error_table[i].msg);
512 	else if (err < 0)
513 		pr_notice("%s: linux error code %i\n", str, err);
514 	else
515 		pr_notice("%s: unknown error code %#2.2x\n",
516 		       str, err);
517 }
518 
519 /*
520  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
521  * apm_info.allow_ints, we are being really paranoid here!  Not only
522  * are interrupts disabled, but all the segment registers (except SS)
523  * are saved and zeroed this means that if the BIOS tries to reference
524  * any data without explicitly loading the segment registers, the kernel
525  * will fault immediately rather than have some unforeseen circumstances
526  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
527  * this depends on CS referring to the same physical memory as DS so that
528  * DS can be zeroed before the call. Unfortunately, we can't do anything
529  * about the stack segment/pointer.  Also, we tell the compiler that
530  * everything could change.
531  *
532  * Also, we KNOW that for the non error case of apm_bios_call, there
533  * is no useful data returned in the low order 8 bits of eax.
534  */
535 
536 static inline unsigned long __apm_irq_save(void)
537 {
538 	unsigned long flags;
539 	local_save_flags(flags);
540 	if (apm_info.allow_ints) {
541 		if (irqs_disabled_flags(flags))
542 			local_irq_enable();
543 	} else
544 		local_irq_disable();
545 
546 	return flags;
547 }
548 
549 #define apm_irq_save(flags) \
550 	do { flags = __apm_irq_save(); } while (0)
551 
552 static inline void apm_irq_restore(unsigned long flags)
553 {
554 	if (irqs_disabled_flags(flags))
555 		local_irq_disable();
556 	else if (irqs_disabled())
557 		local_irq_enable();
558 }
559 
560 #ifdef APM_ZERO_SEGS
561 #	define APM_DECL_SEGS \
562 		unsigned int saved_fs; unsigned int saved_gs;
563 #	define APM_DO_SAVE_SEGS \
564 		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
565 #	define APM_DO_RESTORE_SEGS \
566 		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
567 #else
568 #	define APM_DECL_SEGS
569 #	define APM_DO_SAVE_SEGS
570 #	define APM_DO_RESTORE_SEGS
571 #endif
572 
573 struct apm_bios_call {
574 	u32 func;
575 	/* In and out */
576 	u32 ebx;
577 	u32 ecx;
578 	/* Out only */
579 	u32 eax;
580 	u32 edx;
581 	u32 esi;
582 
583 	/* Error: -ENOMEM, or bits 8-15 of eax */
584 	int err;
585 };
586 
587 /**
588  *	__apm_bios_call - Make an APM BIOS 32bit call
589  *	@_call: pointer to struct apm_bios_call.
590  *
591  *	Make an APM call using the 32bit protected mode interface. The
592  *	caller is responsible for knowing if APM BIOS is configured and
593  *	enabled. This call can disable interrupts for a long period of
594  *	time on some laptops.  The return value is in AH and the carry
595  *	flag is loaded into AL.  If there is an error, then the error
596  *	code is returned in AH (bits 8-15 of eax) and this function
597  *	returns non-zero.
598  *
599  *	Note: this makes the call on the current CPU.
600  */
601 static long __apm_bios_call(void *_call)
602 {
603 	APM_DECL_SEGS
604 	unsigned long		flags;
605 	int			cpu;
606 	struct desc_struct	save_desc_40;
607 	struct desc_struct	*gdt;
608 	struct apm_bios_call	*call = _call;
609 
610 	cpu = get_cpu();
611 	BUG_ON(cpu != 0);
612 	gdt = get_cpu_gdt_table(cpu);
613 	save_desc_40 = gdt[0x40 / 8];
614 	gdt[0x40 / 8] = bad_bios_desc;
615 
616 	apm_irq_save(flags);
617 	APM_DO_SAVE_SEGS;
618 	apm_bios_call_asm(call->func, call->ebx, call->ecx,
619 			  &call->eax, &call->ebx, &call->ecx, &call->edx,
620 			  &call->esi);
621 	APM_DO_RESTORE_SEGS;
622 	apm_irq_restore(flags);
623 	gdt[0x40 / 8] = save_desc_40;
624 	put_cpu();
625 
626 	return call->eax & 0xff;
627 }
628 
629 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
630 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
631 {
632 	int ret;
633 
634 	/* Don't bother with work_on_cpu in the common case, so we don't
635 	 * have to worry about OOM or overhead. */
636 	if (get_cpu() == 0) {
637 		ret = fn(call);
638 		put_cpu();
639 	} else {
640 		put_cpu();
641 		ret = work_on_cpu(0, fn, call);
642 	}
643 
644 	/* work_on_cpu can fail with -ENOMEM */
645 	if (ret < 0)
646 		call->err = ret;
647 	else
648 		call->err = (call->eax >> 8) & 0xff;
649 
650 	return ret;
651 }
652 
653 /**
654  *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
655  *	@call: the apm_bios_call registers.
656  *
657  *	If there is an error, it is returned in @call.err.
658  */
659 static int apm_bios_call(struct apm_bios_call *call)
660 {
661 	return on_cpu0(__apm_bios_call, call);
662 }
663 
664 /**
665  *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
666  *	@_call: pointer to struct apm_bios_call.
667  *
668  *	Make a BIOS call that returns one value only, or just status.
669  *	If there is an error, then the error code is returned in AH
670  *	(bits 8-15 of eax) and this function returns non-zero (it can
671  *	also return -ENOMEM). This is used for simpler BIOS operations.
672  *	This call may hold interrupts off for a long time on some laptops.
673  *
674  *	Note: this makes the call on the current CPU.
675  */
676 static long __apm_bios_call_simple(void *_call)
677 {
678 	u8			error;
679 	APM_DECL_SEGS
680 	unsigned long		flags;
681 	int			cpu;
682 	struct desc_struct	save_desc_40;
683 	struct desc_struct	*gdt;
684 	struct apm_bios_call	*call = _call;
685 
686 	cpu = get_cpu();
687 	BUG_ON(cpu != 0);
688 	gdt = get_cpu_gdt_table(cpu);
689 	save_desc_40 = gdt[0x40 / 8];
690 	gdt[0x40 / 8] = bad_bios_desc;
691 
692 	apm_irq_save(flags);
693 	APM_DO_SAVE_SEGS;
694 	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
695 					 &call->eax);
696 	APM_DO_RESTORE_SEGS;
697 	apm_irq_restore(flags);
698 	gdt[0x40 / 8] = save_desc_40;
699 	put_cpu();
700 	return error;
701 }
702 
703 /**
704  *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
705  *	@func: APM function to invoke
706  *	@ebx_in: EBX register value for BIOS call
707  *	@ecx_in: ECX register value for BIOS call
708  *	@eax: EAX register on return from the BIOS call
709  *	@err: bits
710  *
711  *	Make a BIOS call that returns one value only, or just status.
712  *	If there is an error, then the error code is returned in @err
713  *	and this function returns non-zero. This is used for simpler
714  *	BIOS operations.  This call may hold interrupts off for a long
715  *	time on some laptops.
716  */
717 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
718 				int *err)
719 {
720 	struct apm_bios_call call;
721 	int ret;
722 
723 	call.func = func;
724 	call.ebx = ebx_in;
725 	call.ecx = ecx_in;
726 
727 	ret = on_cpu0(__apm_bios_call_simple, &call);
728 	*eax = call.eax;
729 	*err = call.err;
730 	return ret;
731 }
732 
733 /**
734  *	apm_driver_version	-	APM driver version
735  *	@val:	loaded with the APM version on return
736  *
737  *	Retrieve the APM version supported by the BIOS. This is only
738  *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
739  *	probably present.
740  *
741  *	On entry val should point to a value indicating the APM driver
742  *	version with the high byte being the major and the low byte the
743  *	minor number both in BCD
744  *
745  *	On return it will hold the BIOS revision supported in the
746  *	same format.
747  */
748 
749 static int apm_driver_version(u_short *val)
750 {
751 	u32 eax;
752 	int err;
753 
754 	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
755 		return err;
756 	*val = eax;
757 	return APM_SUCCESS;
758 }
759 
760 /**
761  *	apm_get_event	-	get an APM event from the BIOS
762  *	@event: pointer to the event
763  *	@info: point to the event information
764  *
765  *	The APM BIOS provides a polled information for event
766  *	reporting. The BIOS expects to be polled at least every second
767  *	when events are pending. When a message is found the caller should
768  *	poll until no more messages are present.  However, this causes
769  *	problems on some laptops where a suspend event notification is
770  *	not cleared until it is acknowledged.
771  *
772  *	Additional information is returned in the info pointer, providing
773  *	that APM 1.2 is in use. If no messges are pending the value 0x80
774  *	is returned (No power management events pending).
775  */
776 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
777 {
778 	struct apm_bios_call call;
779 
780 	call.func = APM_FUNC_GET_EVENT;
781 	call.ebx = call.ecx = 0;
782 
783 	if (apm_bios_call(&call))
784 		return call.err;
785 
786 	*event = call.ebx;
787 	if (apm_info.connection_version < 0x0102)
788 		*info = ~0; /* indicate info not valid */
789 	else
790 		*info = call.ecx;
791 	return APM_SUCCESS;
792 }
793 
794 /**
795  *	set_power_state	-	set the power management state
796  *	@what: which items to transition
797  *	@state: state to transition to
798  *
799  *	Request an APM change of state for one or more system devices. The
800  *	processor state must be transitioned last of all. what holds the
801  *	class of device in the upper byte and the device number (0xFF for
802  *	all) for the object to be transitioned.
803  *
804  *	The state holds the state to transition to, which may in fact
805  *	be an acceptance of a BIOS requested state change.
806  */
807 
808 static int set_power_state(u_short what, u_short state)
809 {
810 	u32 eax;
811 	int err;
812 
813 	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
814 		return err;
815 	return APM_SUCCESS;
816 }
817 
818 /**
819  *	set_system_power_state - set system wide power state
820  *	@state: which state to enter
821  *
822  *	Transition the entire system into a new APM power state.
823  */
824 
825 static int set_system_power_state(u_short state)
826 {
827 	return set_power_state(APM_DEVICE_ALL, state);
828 }
829 
830 /**
831  *	apm_do_idle	-	perform power saving
832  *
833  *	This function notifies the BIOS that the processor is (in the view
834  *	of the OS) idle. It returns -1 in the event that the BIOS refuses
835  *	to handle the idle request. On a success the function returns 1
836  *	if the BIOS did clock slowing or 0 otherwise.
837  */
838 
839 static int apm_do_idle(void)
840 {
841 	u32 eax;
842 	u8 ret = 0;
843 	int idled = 0;
844 	int polling;
845 	int err = 0;
846 
847 	if (!need_resched()) {
848 		idled = 1;
849 		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
850 	}
851 
852 	if (!idled)
853 		return 0;
854 
855 	if (ret) {
856 		static unsigned long t;
857 
858 		/* This always fails on some SMP boards running UP kernels.
859 		 * Only report the failure the first 5 times.
860 		 */
861 		if (++t < 5) {
862 			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
863 			t = jiffies;
864 		}
865 		return -1;
866 	}
867 	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
868 	return clock_slowed;
869 }
870 
871 /**
872  *	apm_do_busy	-	inform the BIOS the CPU is busy
873  *
874  *	Request that the BIOS brings the CPU back to full performance.
875  */
876 
877 static void apm_do_busy(void)
878 {
879 	u32 dummy;
880 	int err;
881 
882 	if (clock_slowed || ALWAYS_CALL_BUSY) {
883 		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
884 		clock_slowed = 0;
885 	}
886 }
887 
888 /*
889  * If no process has really been interested in
890  * the CPU for some time, we want to call BIOS
891  * power management - we probably want
892  * to conserve power.
893  */
894 #define IDLE_CALC_LIMIT	(HZ * 100)
895 #define IDLE_LEAKY_MAX	16
896 
897 /**
898  * apm_cpu_idle		-	cpu idling for APM capable Linux
899  *
900  * This is the idling function the kernel executes when APM is available. It
901  * tries to do BIOS powermanagement based on the average system idle time.
902  * Furthermore it calls the system default idle routine.
903  */
904 
905 static int apm_cpu_idle(struct cpuidle_device *dev,
906 	struct cpuidle_driver *drv, int index)
907 {
908 	static int use_apm_idle; /* = 0 */
909 	static unsigned int last_jiffies; /* = 0 */
910 	static unsigned int last_stime; /* = 0 */
911 	cputime_t stime;
912 
913 	int apm_idle_done = 0;
914 	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
915 	unsigned int bucket;
916 
917 recalc:
918 	task_cputime(current, NULL, &stime);
919 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
920 		use_apm_idle = 0;
921 	} else if (jiffies_since_last_check > idle_period) {
922 		unsigned int idle_percentage;
923 
924 		idle_percentage = stime - last_stime;
925 		idle_percentage *= 100;
926 		idle_percentage /= jiffies_since_last_check;
927 		use_apm_idle = (idle_percentage > idle_threshold);
928 		if (apm_info.forbid_idle)
929 			use_apm_idle = 0;
930 	}
931 
932 	last_jiffies = jiffies;
933 	last_stime = stime;
934 
935 	bucket = IDLE_LEAKY_MAX;
936 
937 	while (!need_resched()) {
938 		if (use_apm_idle) {
939 			unsigned int t;
940 
941 			t = jiffies;
942 			switch (apm_do_idle()) {
943 			case 0:
944 				apm_idle_done = 1;
945 				if (t != jiffies) {
946 					if (bucket) {
947 						bucket = IDLE_LEAKY_MAX;
948 						continue;
949 					}
950 				} else if (bucket) {
951 					bucket--;
952 					continue;
953 				}
954 				break;
955 			case 1:
956 				apm_idle_done = 1;
957 				break;
958 			default: /* BIOS refused */
959 				break;
960 			}
961 		}
962 		default_idle();
963 		local_irq_disable();
964 		jiffies_since_last_check = jiffies - last_jiffies;
965 		if (jiffies_since_last_check > idle_period)
966 			goto recalc;
967 	}
968 
969 	if (apm_idle_done)
970 		apm_do_busy();
971 
972 	return index;
973 }
974 
975 /**
976  *	apm_power_off	-	ask the BIOS to power off
977  *
978  *	Handle the power off sequence. This is the one piece of code we
979  *	will execute even on SMP machines. In order to deal with BIOS
980  *	bugs we support real mode APM BIOS power off calls. We also make
981  *	the SMP call on CPU0 as some systems will only honour this call
982  *	on their first cpu.
983  */
984 
985 static void apm_power_off(void)
986 {
987 	/* Some bioses don't like being called from CPU != 0 */
988 	if (apm_info.realmode_power_off) {
989 		set_cpus_allowed_ptr(current, cpumask_of(0));
990 		machine_real_restart(MRR_APM);
991 	} else {
992 		(void)set_system_power_state(APM_STATE_OFF);
993 	}
994 }
995 
996 #ifdef CONFIG_APM_DO_ENABLE
997 
998 /**
999  *	apm_enable_power_management - enable BIOS APM power management
1000  *	@enable: enable yes/no
1001  *
1002  *	Enable or disable the APM BIOS power services.
1003  */
1004 
1005 static int apm_enable_power_management(int enable)
1006 {
1007 	u32 eax;
1008 	int err;
1009 
1010 	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1011 		return APM_NOT_ENGAGED;
1012 	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1013 				 enable, &eax, &err))
1014 		return err;
1015 	if (enable)
1016 		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1017 	else
1018 		apm_info.bios.flags |= APM_BIOS_DISABLED;
1019 	return APM_SUCCESS;
1020 }
1021 #endif
1022 
1023 /**
1024  *	apm_get_power_status	-	get current power state
1025  *	@status: returned status
1026  *	@bat: battery info
1027  *	@life: estimated life
1028  *
1029  *	Obtain the current power status from the APM BIOS. We return a
1030  *	status which gives the rough battery status, and current power
1031  *	source. The bat value returned give an estimate as a percentage
1032  *	of life and a status value for the battery. The estimated life
1033  *	if reported is a lifetime in secodnds/minutes at current powwer
1034  *	consumption.
1035  */
1036 
1037 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1038 {
1039 	struct apm_bios_call call;
1040 
1041 	call.func = APM_FUNC_GET_STATUS;
1042 	call.ebx = APM_DEVICE_ALL;
1043 	call.ecx = 0;
1044 
1045 	if (apm_info.get_power_status_broken)
1046 		return APM_32_UNSUPPORTED;
1047 	if (apm_bios_call(&call))
1048 		return call.err;
1049 	*status = call.ebx;
1050 	*bat = call.ecx;
1051 	if (apm_info.get_power_status_swabinminutes) {
1052 		*life = swab16((u16)call.edx);
1053 		*life |= 0x8000;
1054 	} else
1055 		*life = call.edx;
1056 	return APM_SUCCESS;
1057 }
1058 
1059 #if 0
1060 static int apm_get_battery_status(u_short which, u_short *status,
1061 				  u_short *bat, u_short *life, u_short *nbat)
1062 {
1063 	u32 eax;
1064 	u32 ebx;
1065 	u32 ecx;
1066 	u32 edx;
1067 	u32 esi;
1068 
1069 	if (apm_info.connection_version < 0x0102) {
1070 		/* pretend we only have one battery. */
1071 		if (which != 1)
1072 			return APM_BAD_DEVICE;
1073 		*nbat = 1;
1074 		return apm_get_power_status(status, bat, life);
1075 	}
1076 
1077 	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1078 			  &ebx, &ecx, &edx, &esi))
1079 		return (eax >> 8) & 0xff;
1080 	*status = ebx;
1081 	*bat = ecx;
1082 	*life = edx;
1083 	*nbat = esi;
1084 	return APM_SUCCESS;
1085 }
1086 #endif
1087 
1088 /**
1089  *	apm_engage_power_management	-	enable PM on a device
1090  *	@device: identity of device
1091  *	@enable: on/off
1092  *
1093  *	Activate or deactive power management on either a specific device
1094  *	or the entire system (%APM_DEVICE_ALL).
1095  */
1096 
1097 static int apm_engage_power_management(u_short device, int enable)
1098 {
1099 	u32 eax;
1100 	int err;
1101 
1102 	if ((enable == 0) && (device == APM_DEVICE_ALL)
1103 	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1104 		return APM_DISABLED;
1105 	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1106 				 &eax, &err))
1107 		return err;
1108 	if (device == APM_DEVICE_ALL) {
1109 		if (enable)
1110 			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1111 		else
1112 			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1113 	}
1114 	return APM_SUCCESS;
1115 }
1116 
1117 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1118 
1119 /**
1120  *	apm_console_blank	-	blank the display
1121  *	@blank: on/off
1122  *
1123  *	Attempt to blank the console, firstly by blanking just video device
1124  *	zero, and if that fails (some BIOSes don't support it) then it blanks
1125  *	all video devices. Typically the BIOS will do laptop backlight and
1126  *	monitor powerdown for us.
1127  */
1128 
1129 static int apm_console_blank(int blank)
1130 {
1131 	int error = APM_NOT_ENGAGED; /* silence gcc */
1132 	int i;
1133 	u_short state;
1134 	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1135 
1136 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1137 
1138 	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1139 		error = set_power_state(dev[i], state);
1140 
1141 		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1142 			return 1;
1143 
1144 		if (error == APM_NOT_ENGAGED)
1145 			break;
1146 	}
1147 
1148 	if (error == APM_NOT_ENGAGED) {
1149 		static int tried;
1150 		int eng_error;
1151 		if (tried++ == 0) {
1152 			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1153 			if (eng_error) {
1154 				apm_error("set display", error);
1155 				apm_error("engage interface", eng_error);
1156 				return 0;
1157 			} else
1158 				return apm_console_blank(blank);
1159 		}
1160 	}
1161 	apm_error("set display", error);
1162 	return 0;
1163 }
1164 #endif
1165 
1166 static int queue_empty(struct apm_user *as)
1167 {
1168 	return as->event_head == as->event_tail;
1169 }
1170 
1171 static apm_event_t get_queued_event(struct apm_user *as)
1172 {
1173 	if (++as->event_tail >= APM_MAX_EVENTS)
1174 		as->event_tail = 0;
1175 	return as->events[as->event_tail];
1176 }
1177 
1178 static void queue_event(apm_event_t event, struct apm_user *sender)
1179 {
1180 	struct apm_user *as;
1181 
1182 	spin_lock(&user_list_lock);
1183 	if (user_list == NULL)
1184 		goto out;
1185 	for (as = user_list; as != NULL; as = as->next) {
1186 		if ((as == sender) || (!as->reader))
1187 			continue;
1188 		if (++as->event_head >= APM_MAX_EVENTS)
1189 			as->event_head = 0;
1190 
1191 		if (as->event_head == as->event_tail) {
1192 			static int notified;
1193 
1194 			if (notified++ == 0)
1195 				pr_err("an event queue overflowed\n");
1196 			if (++as->event_tail >= APM_MAX_EVENTS)
1197 				as->event_tail = 0;
1198 		}
1199 		as->events[as->event_head] = event;
1200 		if (!as->suser || !as->writer)
1201 			continue;
1202 		switch (event) {
1203 		case APM_SYS_SUSPEND:
1204 		case APM_USER_SUSPEND:
1205 			as->suspends_pending++;
1206 			suspends_pending++;
1207 			break;
1208 
1209 		case APM_SYS_STANDBY:
1210 		case APM_USER_STANDBY:
1211 			as->standbys_pending++;
1212 			standbys_pending++;
1213 			break;
1214 		}
1215 	}
1216 	wake_up_interruptible(&apm_waitqueue);
1217 out:
1218 	spin_unlock(&user_list_lock);
1219 }
1220 
1221 static void reinit_timer(void)
1222 {
1223 #ifdef INIT_TIMER_AFTER_SUSPEND
1224 	unsigned long flags;
1225 
1226 	raw_spin_lock_irqsave(&i8253_lock, flags);
1227 	/* set the clock to HZ */
1228 	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1229 	udelay(10);
1230 	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1231 	udelay(10);
1232 	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1233 	udelay(10);
1234 	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1235 #endif
1236 }
1237 
1238 static int suspend(int vetoable)
1239 {
1240 	int err;
1241 	struct apm_user	*as;
1242 
1243 	dpm_suspend_start(PMSG_SUSPEND);
1244 	dpm_suspend_end(PMSG_SUSPEND);
1245 
1246 	local_irq_disable();
1247 	syscore_suspend();
1248 
1249 	local_irq_enable();
1250 
1251 	save_processor_state();
1252 	err = set_system_power_state(APM_STATE_SUSPEND);
1253 	ignore_normal_resume = 1;
1254 	restore_processor_state();
1255 
1256 	local_irq_disable();
1257 	reinit_timer();
1258 
1259 	if (err == APM_NO_ERROR)
1260 		err = APM_SUCCESS;
1261 	if (err != APM_SUCCESS)
1262 		apm_error("suspend", err);
1263 	err = (err == APM_SUCCESS) ? 0 : -EIO;
1264 
1265 	syscore_resume();
1266 	local_irq_enable();
1267 
1268 	dpm_resume_start(PMSG_RESUME);
1269 	dpm_resume_end(PMSG_RESUME);
1270 
1271 	queue_event(APM_NORMAL_RESUME, NULL);
1272 	spin_lock(&user_list_lock);
1273 	for (as = user_list; as != NULL; as = as->next) {
1274 		as->suspend_wait = 0;
1275 		as->suspend_result = err;
1276 	}
1277 	spin_unlock(&user_list_lock);
1278 	wake_up_interruptible(&apm_suspend_waitqueue);
1279 	return err;
1280 }
1281 
1282 static void standby(void)
1283 {
1284 	int err;
1285 
1286 	dpm_suspend_end(PMSG_SUSPEND);
1287 
1288 	local_irq_disable();
1289 	syscore_suspend();
1290 	local_irq_enable();
1291 
1292 	err = set_system_power_state(APM_STATE_STANDBY);
1293 	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1294 		apm_error("standby", err);
1295 
1296 	local_irq_disable();
1297 	syscore_resume();
1298 	local_irq_enable();
1299 
1300 	dpm_resume_start(PMSG_RESUME);
1301 }
1302 
1303 static apm_event_t get_event(void)
1304 {
1305 	int error;
1306 	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1307 	apm_eventinfo_t	info;
1308 
1309 	static int notified;
1310 
1311 	/* we don't use the eventinfo */
1312 	error = apm_get_event(&event, &info);
1313 	if (error == APM_SUCCESS)
1314 		return event;
1315 
1316 	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1317 		apm_error("get_event", error);
1318 
1319 	return 0;
1320 }
1321 
1322 static void check_events(void)
1323 {
1324 	apm_event_t event;
1325 	static unsigned long last_resume;
1326 	static int ignore_bounce;
1327 
1328 	while ((event = get_event()) != 0) {
1329 		if (debug) {
1330 			if (event <= NR_APM_EVENT_NAME)
1331 				printk(KERN_DEBUG "apm: received %s notify\n",
1332 				       apm_event_name[event - 1]);
1333 			else
1334 				printk(KERN_DEBUG "apm: received unknown "
1335 				       "event 0x%02x\n", event);
1336 		}
1337 		if (ignore_bounce
1338 		    && (time_after(jiffies, last_resume + bounce_interval)))
1339 			ignore_bounce = 0;
1340 
1341 		switch (event) {
1342 		case APM_SYS_STANDBY:
1343 		case APM_USER_STANDBY:
1344 			queue_event(event, NULL);
1345 			if (standbys_pending <= 0)
1346 				standby();
1347 			break;
1348 
1349 		case APM_USER_SUSPEND:
1350 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1351 			if (apm_info.connection_version > 0x100)
1352 				set_system_power_state(APM_STATE_REJECT);
1353 			break;
1354 #endif
1355 		case APM_SYS_SUSPEND:
1356 			if (ignore_bounce) {
1357 				if (apm_info.connection_version > 0x100)
1358 					set_system_power_state(APM_STATE_REJECT);
1359 				break;
1360 			}
1361 			/*
1362 			 * If we are already processing a SUSPEND,
1363 			 * then further SUSPEND events from the BIOS
1364 			 * will be ignored.  We also return here to
1365 			 * cope with the fact that the Thinkpads keep
1366 			 * sending a SUSPEND event until something else
1367 			 * happens!
1368 			 */
1369 			if (ignore_sys_suspend)
1370 				return;
1371 			ignore_sys_suspend = 1;
1372 			queue_event(event, NULL);
1373 			if (suspends_pending <= 0)
1374 				(void) suspend(1);
1375 			break;
1376 
1377 		case APM_NORMAL_RESUME:
1378 		case APM_CRITICAL_RESUME:
1379 		case APM_STANDBY_RESUME:
1380 			ignore_sys_suspend = 0;
1381 			last_resume = jiffies;
1382 			ignore_bounce = 1;
1383 			if ((event != APM_NORMAL_RESUME)
1384 			    || (ignore_normal_resume == 0)) {
1385 				dpm_resume_end(PMSG_RESUME);
1386 				queue_event(event, NULL);
1387 			}
1388 			ignore_normal_resume = 0;
1389 			break;
1390 
1391 		case APM_CAPABILITY_CHANGE:
1392 		case APM_LOW_BATTERY:
1393 		case APM_POWER_STATUS_CHANGE:
1394 			queue_event(event, NULL);
1395 			/* If needed, notify drivers here */
1396 			break;
1397 
1398 		case APM_UPDATE_TIME:
1399 			break;
1400 
1401 		case APM_CRITICAL_SUSPEND:
1402 			/*
1403 			 * We are not allowed to reject a critical suspend.
1404 			 */
1405 			(void)suspend(0);
1406 			break;
1407 		}
1408 	}
1409 }
1410 
1411 static void apm_event_handler(void)
1412 {
1413 	static int pending_count = 4;
1414 	int err;
1415 
1416 	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1417 		if ((apm_info.connection_version > 0x100) &&
1418 		    (pending_count-- <= 0)) {
1419 			pending_count = 4;
1420 			if (debug)
1421 				printk(KERN_DEBUG "apm: setting state busy\n");
1422 			err = set_system_power_state(APM_STATE_BUSY);
1423 			if (err)
1424 				apm_error("busy", err);
1425 		}
1426 	} else
1427 		pending_count = 4;
1428 	check_events();
1429 }
1430 
1431 /*
1432  * This is the APM thread main loop.
1433  */
1434 
1435 static void apm_mainloop(void)
1436 {
1437 	DECLARE_WAITQUEUE(wait, current);
1438 
1439 	add_wait_queue(&apm_waitqueue, &wait);
1440 	set_current_state(TASK_INTERRUPTIBLE);
1441 	for (;;) {
1442 		schedule_timeout(APM_CHECK_TIMEOUT);
1443 		if (kthread_should_stop())
1444 			break;
1445 		/*
1446 		 * Ok, check all events, check for idle (and mark us sleeping
1447 		 * so as not to count towards the load average)..
1448 		 */
1449 		set_current_state(TASK_INTERRUPTIBLE);
1450 		apm_event_handler();
1451 	}
1452 	remove_wait_queue(&apm_waitqueue, &wait);
1453 }
1454 
1455 static int check_apm_user(struct apm_user *as, const char *func)
1456 {
1457 	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1458 		pr_err("%s passed bad filp\n", func);
1459 		return 1;
1460 	}
1461 	return 0;
1462 }
1463 
1464 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1465 {
1466 	struct apm_user *as;
1467 	int i;
1468 	apm_event_t event;
1469 
1470 	as = fp->private_data;
1471 	if (check_apm_user(as, "read"))
1472 		return -EIO;
1473 	if ((int)count < sizeof(apm_event_t))
1474 		return -EINVAL;
1475 	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1476 		return -EAGAIN;
1477 	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1478 	i = count;
1479 	while ((i >= sizeof(event)) && !queue_empty(as)) {
1480 		event = get_queued_event(as);
1481 		if (copy_to_user(buf, &event, sizeof(event))) {
1482 			if (i < count)
1483 				break;
1484 			return -EFAULT;
1485 		}
1486 		switch (event) {
1487 		case APM_SYS_SUSPEND:
1488 		case APM_USER_SUSPEND:
1489 			as->suspends_read++;
1490 			break;
1491 
1492 		case APM_SYS_STANDBY:
1493 		case APM_USER_STANDBY:
1494 			as->standbys_read++;
1495 			break;
1496 		}
1497 		buf += sizeof(event);
1498 		i -= sizeof(event);
1499 	}
1500 	if (i < count)
1501 		return count - i;
1502 	if (signal_pending(current))
1503 		return -ERESTARTSYS;
1504 	return 0;
1505 }
1506 
1507 static unsigned int do_poll(struct file *fp, poll_table *wait)
1508 {
1509 	struct apm_user *as;
1510 
1511 	as = fp->private_data;
1512 	if (check_apm_user(as, "poll"))
1513 		return 0;
1514 	poll_wait(fp, &apm_waitqueue, wait);
1515 	if (!queue_empty(as))
1516 		return POLLIN | POLLRDNORM;
1517 	return 0;
1518 }
1519 
1520 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1521 {
1522 	struct apm_user *as;
1523 	int ret;
1524 
1525 	as = filp->private_data;
1526 	if (check_apm_user(as, "ioctl"))
1527 		return -EIO;
1528 	if (!as->suser || !as->writer)
1529 		return -EPERM;
1530 	switch (cmd) {
1531 	case APM_IOC_STANDBY:
1532 		mutex_lock(&apm_mutex);
1533 		if (as->standbys_read > 0) {
1534 			as->standbys_read--;
1535 			as->standbys_pending--;
1536 			standbys_pending--;
1537 		} else
1538 			queue_event(APM_USER_STANDBY, as);
1539 		if (standbys_pending <= 0)
1540 			standby();
1541 		mutex_unlock(&apm_mutex);
1542 		break;
1543 	case APM_IOC_SUSPEND:
1544 		mutex_lock(&apm_mutex);
1545 		if (as->suspends_read > 0) {
1546 			as->suspends_read--;
1547 			as->suspends_pending--;
1548 			suspends_pending--;
1549 		} else
1550 			queue_event(APM_USER_SUSPEND, as);
1551 		if (suspends_pending <= 0) {
1552 			ret = suspend(1);
1553 			mutex_unlock(&apm_mutex);
1554 		} else {
1555 			as->suspend_wait = 1;
1556 			mutex_unlock(&apm_mutex);
1557 			wait_event_interruptible(apm_suspend_waitqueue,
1558 					as->suspend_wait == 0);
1559 			ret = as->suspend_result;
1560 		}
1561 		return ret;
1562 	default:
1563 		return -ENOTTY;
1564 	}
1565 	return 0;
1566 }
1567 
1568 static int do_release(struct inode *inode, struct file *filp)
1569 {
1570 	struct apm_user *as;
1571 
1572 	as = filp->private_data;
1573 	if (check_apm_user(as, "release"))
1574 		return 0;
1575 	filp->private_data = NULL;
1576 	if (as->standbys_pending > 0) {
1577 		standbys_pending -= as->standbys_pending;
1578 		if (standbys_pending <= 0)
1579 			standby();
1580 	}
1581 	if (as->suspends_pending > 0) {
1582 		suspends_pending -= as->suspends_pending;
1583 		if (suspends_pending <= 0)
1584 			(void) suspend(1);
1585 	}
1586 	spin_lock(&user_list_lock);
1587 	if (user_list == as)
1588 		user_list = as->next;
1589 	else {
1590 		struct apm_user *as1;
1591 
1592 		for (as1 = user_list;
1593 		     (as1 != NULL) && (as1->next != as);
1594 		     as1 = as1->next)
1595 			;
1596 		if (as1 == NULL)
1597 			pr_err("filp not in user list\n");
1598 		else
1599 			as1->next = as->next;
1600 	}
1601 	spin_unlock(&user_list_lock);
1602 	kfree(as);
1603 	return 0;
1604 }
1605 
1606 static int do_open(struct inode *inode, struct file *filp)
1607 {
1608 	struct apm_user *as;
1609 
1610 	as = kmalloc(sizeof(*as), GFP_KERNEL);
1611 	if (as == NULL)
1612 		return -ENOMEM;
1613 
1614 	as->magic = APM_BIOS_MAGIC;
1615 	as->event_tail = as->event_head = 0;
1616 	as->suspends_pending = as->standbys_pending = 0;
1617 	as->suspends_read = as->standbys_read = 0;
1618 	/*
1619 	 * XXX - this is a tiny bit broken, when we consider BSD
1620 	 * process accounting. If the device is opened by root, we
1621 	 * instantly flag that we used superuser privs. Who knows,
1622 	 * we might close the device immediately without doing a
1623 	 * privileged operation -- cevans
1624 	 */
1625 	as->suser = capable(CAP_SYS_ADMIN);
1626 	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1627 	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1628 	spin_lock(&user_list_lock);
1629 	as->next = user_list;
1630 	user_list = as;
1631 	spin_unlock(&user_list_lock);
1632 	filp->private_data = as;
1633 	return 0;
1634 }
1635 
1636 static int proc_apm_show(struct seq_file *m, void *v)
1637 {
1638 	unsigned short	bx;
1639 	unsigned short	cx;
1640 	unsigned short	dx;
1641 	int		error;
1642 	unsigned short  ac_line_status = 0xff;
1643 	unsigned short  battery_status = 0xff;
1644 	unsigned short  battery_flag   = 0xff;
1645 	int		percentage     = -1;
1646 	int             time_units     = -1;
1647 	char            *units         = "?";
1648 
1649 	if ((num_online_cpus() == 1) &&
1650 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1651 		ac_line_status = (bx >> 8) & 0xff;
1652 		battery_status = bx & 0xff;
1653 		if ((cx & 0xff) != 0xff)
1654 			percentage = cx & 0xff;
1655 
1656 		if (apm_info.connection_version > 0x100) {
1657 			battery_flag = (cx >> 8) & 0xff;
1658 			if (dx != 0xffff) {
1659 				units = (dx & 0x8000) ? "min" : "sec";
1660 				time_units = dx & 0x7fff;
1661 			}
1662 		}
1663 	}
1664 	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1665 	   from the Get Power Status (0x0a) call unless otherwise noted.
1666 
1667 	   0) Linux driver version (this will change if format changes)
1668 	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1669 	   2) APM flags from APM Installation Check (0x00):
1670 	      bit 0: APM_16_BIT_SUPPORT
1671 	      bit 1: APM_32_BIT_SUPPORT
1672 	      bit 2: APM_IDLE_SLOWS_CLOCK
1673 	      bit 3: APM_BIOS_DISABLED
1674 	      bit 4: APM_BIOS_DISENGAGED
1675 	   3) AC line status
1676 	      0x00: Off-line
1677 	      0x01: On-line
1678 	      0x02: On backup power (BIOS >= 1.1 only)
1679 	      0xff: Unknown
1680 	   4) Battery status
1681 	      0x00: High
1682 	      0x01: Low
1683 	      0x02: Critical
1684 	      0x03: Charging
1685 	      0x04: Selected battery not present (BIOS >= 1.2 only)
1686 	      0xff: Unknown
1687 	   5) Battery flag
1688 	      bit 0: High
1689 	      bit 1: Low
1690 	      bit 2: Critical
1691 	      bit 3: Charging
1692 	      bit 7: No system battery
1693 	      0xff: Unknown
1694 	   6) Remaining battery life (percentage of charge):
1695 	      0-100: valid
1696 	      -1: Unknown
1697 	   7) Remaining battery life (time units):
1698 	      Number of remaining minutes or seconds
1699 	      -1: Unknown
1700 	   8) min = minutes; sec = seconds */
1701 
1702 	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1703 		   driver_version,
1704 		   (apm_info.bios.version >> 8) & 0xff,
1705 		   apm_info.bios.version & 0xff,
1706 		   apm_info.bios.flags,
1707 		   ac_line_status,
1708 		   battery_status,
1709 		   battery_flag,
1710 		   percentage,
1711 		   time_units,
1712 		   units);
1713 	return 0;
1714 }
1715 
1716 static int proc_apm_open(struct inode *inode, struct file *file)
1717 {
1718 	return single_open(file, proc_apm_show, NULL);
1719 }
1720 
1721 static const struct file_operations apm_file_ops = {
1722 	.owner		= THIS_MODULE,
1723 	.open		= proc_apm_open,
1724 	.read		= seq_read,
1725 	.llseek		= seq_lseek,
1726 	.release	= single_release,
1727 };
1728 
1729 static int apm(void *unused)
1730 {
1731 	unsigned short	bx;
1732 	unsigned short	cx;
1733 	unsigned short	dx;
1734 	int		error;
1735 	char 		*power_stat;
1736 	char 		*bat_stat;
1737 
1738 	/* 2002/08/01 - WT
1739 	 * This is to avoid random crashes at boot time during initialization
1740 	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1741 	 * Some bioses don't like being called from CPU != 0.
1742 	 * Method suggested by Ingo Molnar.
1743 	 */
1744 	set_cpus_allowed_ptr(current, cpumask_of(0));
1745 	BUG_ON(smp_processor_id() != 0);
1746 
1747 	if (apm_info.connection_version == 0) {
1748 		apm_info.connection_version = apm_info.bios.version;
1749 		if (apm_info.connection_version > 0x100) {
1750 			/*
1751 			 * We only support BIOSs up to version 1.2
1752 			 */
1753 			if (apm_info.connection_version > 0x0102)
1754 				apm_info.connection_version = 0x0102;
1755 			error = apm_driver_version(&apm_info.connection_version);
1756 			if (error != APM_SUCCESS) {
1757 				apm_error("driver version", error);
1758 				/* Fall back to an APM 1.0 connection. */
1759 				apm_info.connection_version = 0x100;
1760 			}
1761 		}
1762 	}
1763 
1764 	if (debug)
1765 		printk(KERN_INFO "apm: Connection version %d.%d\n",
1766 			(apm_info.connection_version >> 8) & 0xff,
1767 			apm_info.connection_version & 0xff);
1768 
1769 #ifdef CONFIG_APM_DO_ENABLE
1770 	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1771 		/*
1772 		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1773 		 * is booted with PM disabled but not in the docking station.
1774 		 * Unfortunate ...
1775 		 */
1776 		error = apm_enable_power_management(1);
1777 		if (error) {
1778 			apm_error("enable power management", error);
1779 			return -1;
1780 		}
1781 	}
1782 #endif
1783 
1784 	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1785 	    && (apm_info.connection_version > 0x0100)) {
1786 		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1787 		if (error) {
1788 			apm_error("engage power management", error);
1789 			return -1;
1790 		}
1791 	}
1792 
1793 	if (debug && (num_online_cpus() == 1 || smp)) {
1794 		error = apm_get_power_status(&bx, &cx, &dx);
1795 		if (error)
1796 			printk(KERN_INFO "apm: power status not available\n");
1797 		else {
1798 			switch ((bx >> 8) & 0xff) {
1799 			case 0:
1800 				power_stat = "off line";
1801 				break;
1802 			case 1:
1803 				power_stat = "on line";
1804 				break;
1805 			case 2:
1806 				power_stat = "on backup power";
1807 				break;
1808 			default:
1809 				power_stat = "unknown";
1810 				break;
1811 			}
1812 			switch (bx & 0xff) {
1813 			case 0:
1814 				bat_stat = "high";
1815 				break;
1816 			case 1:
1817 				bat_stat = "low";
1818 				break;
1819 			case 2:
1820 				bat_stat = "critical";
1821 				break;
1822 			case 3:
1823 				bat_stat = "charging";
1824 				break;
1825 			default:
1826 				bat_stat = "unknown";
1827 				break;
1828 			}
1829 			printk(KERN_INFO
1830 			       "apm: AC %s, battery status %s, battery life ",
1831 			       power_stat, bat_stat);
1832 			if ((cx & 0xff) == 0xff)
1833 				printk("unknown\n");
1834 			else
1835 				printk("%d%%\n", cx & 0xff);
1836 			if (apm_info.connection_version > 0x100) {
1837 				printk(KERN_INFO
1838 				       "apm: battery flag 0x%02x, battery life ",
1839 				       (cx >> 8) & 0xff);
1840 				if (dx == 0xffff)
1841 					printk("unknown\n");
1842 				else
1843 					printk("%d %s\n", dx & 0x7fff,
1844 					       (dx & 0x8000) ?
1845 					       "minutes" : "seconds");
1846 			}
1847 		}
1848 	}
1849 
1850 	/* Install our power off handler.. */
1851 	if (power_off)
1852 		pm_power_off = apm_power_off;
1853 
1854 	if (num_online_cpus() == 1 || smp) {
1855 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1856 		console_blank_hook = apm_console_blank;
1857 #endif
1858 		apm_mainloop();
1859 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1860 		console_blank_hook = NULL;
1861 #endif
1862 	}
1863 
1864 	return 0;
1865 }
1866 
1867 #ifndef MODULE
1868 static int __init apm_setup(char *str)
1869 {
1870 	int invert;
1871 
1872 	while ((str != NULL) && (*str != '\0')) {
1873 		if (strncmp(str, "off", 3) == 0)
1874 			apm_disabled = 1;
1875 		if (strncmp(str, "on", 2) == 0)
1876 			apm_disabled = 0;
1877 		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1878 		    (strncmp(str, "bounce_interval=", 16) == 0))
1879 			bounce_interval = simple_strtol(str + 16, NULL, 0);
1880 		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1881 		    (strncmp(str, "idle_threshold=", 15) == 0))
1882 			idle_threshold = simple_strtol(str + 15, NULL, 0);
1883 		if ((strncmp(str, "idle-period=", 12) == 0) ||
1884 		    (strncmp(str, "idle_period=", 12) == 0))
1885 			idle_period = simple_strtol(str + 12, NULL, 0);
1886 		invert = (strncmp(str, "no-", 3) == 0) ||
1887 			(strncmp(str, "no_", 3) == 0);
1888 		if (invert)
1889 			str += 3;
1890 		if (strncmp(str, "debug", 5) == 0)
1891 			debug = !invert;
1892 		if ((strncmp(str, "power-off", 9) == 0) ||
1893 		    (strncmp(str, "power_off", 9) == 0))
1894 			power_off = !invert;
1895 		if (strncmp(str, "smp", 3) == 0) {
1896 			smp = !invert;
1897 			idle_threshold = 100;
1898 		}
1899 		if ((strncmp(str, "allow-ints", 10) == 0) ||
1900 		    (strncmp(str, "allow_ints", 10) == 0))
1901 			apm_info.allow_ints = !invert;
1902 		if ((strncmp(str, "broken-psr", 10) == 0) ||
1903 		    (strncmp(str, "broken_psr", 10) == 0))
1904 			apm_info.get_power_status_broken = !invert;
1905 		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1906 		    (strncmp(str, "realmode_power_off", 18) == 0))
1907 			apm_info.realmode_power_off = !invert;
1908 		str = strchr(str, ',');
1909 		if (str != NULL)
1910 			str += strspn(str, ", \t");
1911 	}
1912 	return 1;
1913 }
1914 
1915 __setup("apm=", apm_setup);
1916 #endif
1917 
1918 static const struct file_operations apm_bios_fops = {
1919 	.owner		= THIS_MODULE,
1920 	.read		= do_read,
1921 	.poll		= do_poll,
1922 	.unlocked_ioctl	= do_ioctl,
1923 	.open		= do_open,
1924 	.release	= do_release,
1925 	.llseek		= noop_llseek,
1926 };
1927 
1928 static struct miscdevice apm_device = {
1929 	APM_MINOR_DEV,
1930 	"apm_bios",
1931 	&apm_bios_fops
1932 };
1933 
1934 
1935 /* Simple "print if true" callback */
1936 static int __init print_if_true(const struct dmi_system_id *d)
1937 {
1938 	printk("%s\n", d->ident);
1939 	return 0;
1940 }
1941 
1942 /*
1943  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1944  * disabled before the suspend. Linux used to get terribly confused by that.
1945  */
1946 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1947 {
1948 	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1949 	       "workaround hopefully not needed.\n", d->ident);
1950 	return 0;
1951 }
1952 
1953 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1954 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1955 {
1956 	if (apm_info.realmode_power_off == 0) {
1957 		apm_info.realmode_power_off = 1;
1958 		printk(KERN_INFO "%s bios detected. "
1959 		       "Using realmode poweroff only.\n", d->ident);
1960 	}
1961 	return 0;
1962 }
1963 
1964 /* Some laptops require interrupts to be enabled during APM calls */
1965 static int __init set_apm_ints(const struct dmi_system_id *d)
1966 {
1967 	if (apm_info.allow_ints == 0) {
1968 		apm_info.allow_ints = 1;
1969 		printk(KERN_INFO "%s machine detected. "
1970 		       "Enabling interrupts during APM calls.\n", d->ident);
1971 	}
1972 	return 0;
1973 }
1974 
1975 /* Some APM bioses corrupt memory or just plain do not work */
1976 static int __init apm_is_horked(const struct dmi_system_id *d)
1977 {
1978 	if (apm_info.disabled == 0) {
1979 		apm_info.disabled = 1;
1980 		printk(KERN_INFO "%s machine detected. "
1981 		       "Disabling APM.\n", d->ident);
1982 	}
1983 	return 0;
1984 }
1985 
1986 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1987 {
1988 	if (apm_info.disabled == 0) {
1989 		apm_info.disabled = 1;
1990 		printk(KERN_INFO "%s machine detected. "
1991 		       "Disabling APM.\n", d->ident);
1992 		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1993 		printk(KERN_INFO "download from support.intel.com\n");
1994 	}
1995 	return 0;
1996 }
1997 
1998 /* Some APM bioses hang on APM idle calls */
1999 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2000 {
2001 	if (apm_info.forbid_idle == 0) {
2002 		apm_info.forbid_idle = 1;
2003 		printk(KERN_INFO "%s machine detected. "
2004 		       "Disabling APM idle calls.\n", d->ident);
2005 	}
2006 	return 0;
2007 }
2008 
2009 /*
2010  *  Check for clue free BIOS implementations who use
2011  *  the following QA technique
2012  *
2013  *      [ Write BIOS Code ]<------
2014  *               |                ^
2015  *      < Does it Compile >----N--
2016  *               |Y               ^
2017  *	< Does it Boot Win98 >-N--
2018  *               |Y
2019  *           [Ship It]
2020  *
2021  *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2022  *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2023  */
2024 static int __init broken_apm_power(const struct dmi_system_id *d)
2025 {
2026 	apm_info.get_power_status_broken = 1;
2027 	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2028 	       "disabling power status reporting.\n");
2029 	return 0;
2030 }
2031 
2032 /*
2033  * This bios swaps the APM minute reporting bytes over (Many sony laptops
2034  * have this problem).
2035  */
2036 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2037 {
2038 	apm_info.get_power_status_swabinminutes = 1;
2039 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2040 	       "in minutes and wrong byte order.\n");
2041 	return 0;
2042 }
2043 
2044 static struct dmi_system_id __initdata apm_dmi_table[] = {
2045 	{
2046 		print_if_true,
2047 		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2048 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2049 			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2050 	},
2051 	{	/* Handle problems with APM on the C600 */
2052 		broken_ps2_resume, "Dell Latitude C600",
2053 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2054 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2055 	},
2056 	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2057 		set_apm_ints, "Dell Latitude",
2058 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2059 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2060 	},
2061 	{	/* APM crashes */
2062 		apm_is_horked, "Dell Inspiron 2500",
2063 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2064 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2065 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2066 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2067 	},
2068 	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2069 		set_apm_ints, "Dell Inspiron", {
2070 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2071 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2072 	},
2073 	{	/* Handle problems with APM on Inspiron 5000e */
2074 		broken_apm_power, "Dell Inspiron 5000e",
2075 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2076 			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2077 			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2078 	},
2079 	{	/* Handle problems with APM on Inspiron 2500 */
2080 		broken_apm_power, "Dell Inspiron 2500",
2081 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2082 			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2083 			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2084 	},
2085 	{	/* APM crashes */
2086 		apm_is_horked, "Dell Dimension 4100",
2087 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2088 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2089 			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2090 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2091 	},
2092 	{	/* Allow interrupts during suspend on Compaq Laptops*/
2093 		set_apm_ints, "Compaq 12XL125",
2094 		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2095 			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2096 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2097 			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2098 	},
2099 	{	/* Allow interrupts during APM or the clock goes slow */
2100 		set_apm_ints, "ASUSTeK",
2101 		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2102 			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2103 	},
2104 	{	/* APM blows on shutdown */
2105 		apm_is_horked, "ABIT KX7-333[R]",
2106 		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2107 			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2108 	},
2109 	{	/* APM crashes */
2110 		apm_is_horked, "Trigem Delhi3",
2111 		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2112 			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2113 	},
2114 	{	/* APM crashes */
2115 		apm_is_horked, "Fujitsu-Siemens",
2116 		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2117 			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2118 	},
2119 	{	/* APM crashes */
2120 		apm_is_horked_d850md, "Intel D850MD",
2121 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2122 			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2123 	},
2124 	{	/* APM crashes */
2125 		apm_is_horked, "Intel D810EMO",
2126 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2127 			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2128 	},
2129 	{	/* APM crashes */
2130 		apm_is_horked, "Dell XPS-Z",
2131 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2132 			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2133 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2134 	},
2135 	{	/* APM crashes */
2136 		apm_is_horked, "Sharp PC-PJ/AX",
2137 		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2138 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2139 			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2140 			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2141 	},
2142 	{	/* APM crashes */
2143 		apm_is_horked, "Dell Inspiron 2500",
2144 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2145 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2146 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2147 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2148 	},
2149 	{	/* APM idle hangs */
2150 		apm_likes_to_melt, "Jabil AMD",
2151 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2152 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2153 	},
2154 	{	/* APM idle hangs */
2155 		apm_likes_to_melt, "AMI Bios",
2156 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2157 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2158 	},
2159 	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2160 		swab_apm_power_in_minutes, "Sony VAIO",
2161 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162 			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2163 			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2164 	},
2165 	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2166 		swab_apm_power_in_minutes, "Sony VAIO",
2167 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168 			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2169 			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2170 	},
2171 	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2172 		swab_apm_power_in_minutes, "Sony VAIO",
2173 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174 			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2175 			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2176 	},
2177 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2178 		swab_apm_power_in_minutes, "Sony VAIO",
2179 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2180 			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2181 			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2182 	},
2183 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2184 		swab_apm_power_in_minutes, "Sony VAIO",
2185 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2186 			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2187 			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2188 	},
2189 	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2190 		swab_apm_power_in_minutes, "Sony VAIO",
2191 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192 			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2193 			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2194 	},
2195 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2196 		swab_apm_power_in_minutes, "Sony VAIO",
2197 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2198 			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2199 			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2200 	},
2201 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2202 		swab_apm_power_in_minutes, "Sony VAIO",
2203 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204 			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2205 			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2206 	},
2207 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2208 		swab_apm_power_in_minutes, "Sony VAIO",
2209 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210 			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2211 			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2212 	},
2213 	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2214 		swab_apm_power_in_minutes, "Sony VAIO",
2215 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2216 			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2217 			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2218 	},
2219 
2220 	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2221 		swab_apm_power_in_minutes, "Sony VAIO",
2222 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2223 			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2224 			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2225 	},
2226 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2227 		swab_apm_power_in_minutes, "Sony VAIO",
2228 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2229 			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2230 			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2231 	},
2232 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2233 		swab_apm_power_in_minutes, "Sony VAIO",
2234 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2235 			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2236 			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2237 	},
2238 	{	/* broken PM poweroff bios */
2239 		set_realmode_power_off, "Award Software v4.60 PGMA",
2240 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2241 			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2242 			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2243 	},
2244 
2245 	/* Generic per vendor APM settings  */
2246 
2247 	{	/* Allow interrupts during suspend on IBM laptops */
2248 		set_apm_ints, "IBM",
2249 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2250 	},
2251 
2252 	{ }
2253 };
2254 
2255 /*
2256  * Just start the APM thread. We do NOT want to do APM BIOS
2257  * calls from anything but the APM thread, if for no other reason
2258  * than the fact that we don't trust the APM BIOS. This way,
2259  * most common APM BIOS problems that lead to protection errors
2260  * etc will have at least some level of being contained...
2261  *
2262  * In short, if something bad happens, at least we have a choice
2263  * of just killing the apm thread..
2264  */
2265 static int __init apm_init(void)
2266 {
2267 	struct desc_struct *gdt;
2268 	int err;
2269 
2270 	dmi_check_system(apm_dmi_table);
2271 
2272 	if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2273 		printk(KERN_INFO "apm: BIOS not found.\n");
2274 		return -ENODEV;
2275 	}
2276 	printk(KERN_INFO
2277 	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2278 	       ((apm_info.bios.version >> 8) & 0xff),
2279 	       (apm_info.bios.version & 0xff),
2280 	       apm_info.bios.flags,
2281 	       driver_version);
2282 	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2283 		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2284 		return -ENODEV;
2285 	}
2286 
2287 	if (allow_ints)
2288 		apm_info.allow_ints = 1;
2289 	if (broken_psr)
2290 		apm_info.get_power_status_broken = 1;
2291 	if (realmode_power_off)
2292 		apm_info.realmode_power_off = 1;
2293 	/* User can override, but default is to trust DMI */
2294 	if (apm_disabled != -1)
2295 		apm_info.disabled = apm_disabled;
2296 
2297 	/*
2298 	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2299 	 * but is reportedly a 1.0 BIOS.
2300 	 */
2301 	if (apm_info.bios.version == 0x001)
2302 		apm_info.bios.version = 0x100;
2303 
2304 	/* BIOS < 1.2 doesn't set cseg_16_len */
2305 	if (apm_info.bios.version < 0x102)
2306 		apm_info.bios.cseg_16_len = 0; /* 64k */
2307 
2308 	if (debug) {
2309 		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2310 			apm_info.bios.cseg, apm_info.bios.offset,
2311 			apm_info.bios.cseg_16, apm_info.bios.dseg);
2312 		if (apm_info.bios.version > 0x100)
2313 			printk(" cseg len %x, dseg len %x",
2314 				apm_info.bios.cseg_len,
2315 				apm_info.bios.dseg_len);
2316 		if (apm_info.bios.version > 0x101)
2317 			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2318 		printk("\n");
2319 	}
2320 
2321 	if (apm_info.disabled) {
2322 		pr_notice("disabled on user request.\n");
2323 		return -ENODEV;
2324 	}
2325 	if ((num_online_cpus() > 1) && !power_off && !smp) {
2326 		pr_notice("disabled - APM is not SMP safe.\n");
2327 		apm_info.disabled = 1;
2328 		return -ENODEV;
2329 	}
2330 	if (!acpi_disabled) {
2331 		pr_notice("overridden by ACPI.\n");
2332 		apm_info.disabled = 1;
2333 		return -ENODEV;
2334 	}
2335 
2336 	/*
2337 	 * Set up the long jump entry point to the APM BIOS, which is called
2338 	 * from inline assembly.
2339 	 */
2340 	apm_bios_entry.offset = apm_info.bios.offset;
2341 	apm_bios_entry.segment = APM_CS;
2342 
2343 	/*
2344 	 * The APM 1.1 BIOS is supposed to provide limit information that it
2345 	 * recognizes.  Many machines do this correctly, but many others do
2346 	 * not restrict themselves to their claimed limit.  When this happens,
2347 	 * they will cause a segmentation violation in the kernel at boot time.
2348 	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2349 	 *
2350 	 * Note we only set APM segments on CPU zero, since we pin the APM
2351 	 * code to that CPU.
2352 	 */
2353 	gdt = get_cpu_gdt_table(0);
2354 	set_desc_base(&gdt[APM_CS >> 3],
2355 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2356 	set_desc_base(&gdt[APM_CS_16 >> 3],
2357 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2358 	set_desc_base(&gdt[APM_DS >> 3],
2359 		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2360 
2361 	proc_create("apm", 0, NULL, &apm_file_ops);
2362 
2363 	kapmd_task = kthread_create(apm, NULL, "kapmd");
2364 	if (IS_ERR(kapmd_task)) {
2365 		pr_err("disabled - Unable to start kernel thread\n");
2366 		err = PTR_ERR(kapmd_task);
2367 		kapmd_task = NULL;
2368 		remove_proc_entry("apm", NULL);
2369 		return err;
2370 	}
2371 	wake_up_process(kapmd_task);
2372 
2373 	if (num_online_cpus() > 1 && !smp) {
2374 		printk(KERN_NOTICE
2375 		       "apm: disabled - APM is not SMP safe (power off active).\n");
2376 		return 0;
2377 	}
2378 
2379 	/*
2380 	 * Note we don't actually care if the misc_device cannot be registered.
2381 	 * this driver can do its job without it, even if userspace can't
2382 	 * control it.  just log the error
2383 	 */
2384 	if (misc_register(&apm_device))
2385 		printk(KERN_WARNING "apm: Could not register misc device.\n");
2386 
2387 	if (HZ != 100)
2388 		idle_period = (idle_period * HZ) / 100;
2389 	if (idle_threshold < 100) {
2390 		if (!cpuidle_register_driver(&apm_idle_driver))
2391 			if (cpuidle_register_device(&apm_cpuidle_device))
2392 				cpuidle_unregister_driver(&apm_idle_driver);
2393 	}
2394 
2395 	return 0;
2396 }
2397 
2398 static void __exit apm_exit(void)
2399 {
2400 	int error;
2401 
2402 	cpuidle_unregister_device(&apm_cpuidle_device);
2403 	cpuidle_unregister_driver(&apm_idle_driver);
2404 
2405 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2406 	    && (apm_info.connection_version > 0x0100)) {
2407 		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2408 		if (error)
2409 			apm_error("disengage power management", error);
2410 	}
2411 	misc_deregister(&apm_device);
2412 	remove_proc_entry("apm", NULL);
2413 	if (power_off)
2414 		pm_power_off = NULL;
2415 	if (kapmd_task) {
2416 		kthread_stop(kapmd_task);
2417 		kapmd_task = NULL;
2418 	}
2419 }
2420 
2421 module_init(apm_init);
2422 module_exit(apm_exit);
2423 
2424 MODULE_AUTHOR("Stephen Rothwell");
2425 MODULE_DESCRIPTION("Advanced Power Management");
2426 MODULE_LICENSE("GPL");
2427 module_param(debug, bool, 0644);
2428 MODULE_PARM_DESC(debug, "Enable debug mode");
2429 module_param(power_off, bool, 0444);
2430 MODULE_PARM_DESC(power_off, "Enable power off");
2431 module_param(bounce_interval, int, 0444);
2432 MODULE_PARM_DESC(bounce_interval,
2433 		"Set the number of ticks to ignore suspend bounces");
2434 module_param(allow_ints, bool, 0444);
2435 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2436 module_param(broken_psr, bool, 0444);
2437 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2438 module_param(realmode_power_off, bool, 0444);
2439 MODULE_PARM_DESC(realmode_power_off,
2440 		"Switch to real mode before powering off");
2441 module_param(idle_threshold, int, 0444);
2442 MODULE_PARM_DESC(idle_threshold,
2443 	"System idle percentage above which to make APM BIOS idle calls");
2444 module_param(idle_period, int, 0444);
2445 MODULE_PARM_DESC(idle_period,
2446 	"Period (in sec/100) over which to caculate the idle percentage");
2447 module_param(smp, bool, 0444);
2448 MODULE_PARM_DESC(smp,
2449 	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2450 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2451