xref: /openbmc/linux/arch/x86/kernel/apm_32.c (revision ab73b751)
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 #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/capability.h>
222 #include <linux/device.h>
223 #include <linux/kernel.h>
224 #include <linux/freezer.h>
225 #include <linux/smp.h>
226 #include <linux/dmi.h>
227 #include <linux/suspend.h>
228 #include <linux/kthread.h>
229 #include <linux/jiffies.h>
230 #include <linux/acpi.h>
231 #include <linux/syscore_ops.h>
232 #include <linux/i8253.h>
233 
234 #include <asm/uaccess.h>
235 #include <asm/desc.h>
236 #include <asm/olpc.h>
237 #include <asm/paravirt.h>
238 #include <asm/reboot.h>
239 
240 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
241 extern int (*console_blank_hook)(int);
242 #endif
243 
244 /*
245  * The apm_bios device is one of the misc char devices.
246  * This is its minor number.
247  */
248 #define	APM_MINOR_DEV	134
249 
250 /*
251  * Various options can be changed at boot time as follows:
252  * (We allow underscores for compatibility with the modules code)
253  *	apm=on/off			enable/disable APM
254  *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
255  *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
256  *	    [no-]realmode[-_]power[-_]off	switch to real mode before
257  *	    					powering off
258  *	    [no-]debug			log some debugging messages
259  *	    [no-]power[-_]off		power off on shutdown
260  *	    [no-]smp			Use apm even on an SMP box
261  *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
262  *	    				bounces
263  *          idle[-_]threshold=<n>       System idle percentage above which to
264  *                                      make APM BIOS idle calls. Set it to
265  *                                      100 to disable.
266  *          idle[-_]period=<n>          Period (in 1/100s of a second) over
267  *                                      which the idle percentage is
268  *                                      calculated.
269  */
270 
271 /* KNOWN PROBLEM MACHINES:
272  *
273  * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
274  *                         [Confirmed by TI representative]
275  * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
276  *                    [Confirmed by BIOS disassembly]
277  *                    [This may work now ...]
278  * P: Toshiba 1950S: battery life information only gets updated after resume
279  * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
280  * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
281  * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
282  * 	Neale Banks <neale@lowendale.com.au> December 2000
283  *
284  * Legend: U = unusable with APM patches
285  *         P = partially usable with APM patches
286  */
287 
288 /*
289  * Define as 1 to make the driver always call the APM BIOS busy
290  * routine even if the clock was not reported as slowed by the
291  * idle routine.  Otherwise, define as 0.
292  */
293 #define ALWAYS_CALL_BUSY   1
294 
295 /*
296  * Define to make the APM BIOS calls zero all data segment registers (so
297  * that an incorrect BIOS implementation will cause a kernel panic if it
298  * tries to write to arbitrary memory).
299  */
300 #define APM_ZERO_SEGS
301 
302 #include <asm/apm.h>
303 
304 /*
305  * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
306  * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
307  * David Chen <chen@ctpa04.mit.edu>
308  */
309 #undef INIT_TIMER_AFTER_SUSPEND
310 
311 #ifdef INIT_TIMER_AFTER_SUSPEND
312 #include <linux/timex.h>
313 #include <asm/io.h>
314 #include <linux/delay.h>
315 #endif
316 
317 /*
318  * Need to poll the APM BIOS every second
319  */
320 #define APM_CHECK_TIMEOUT	(HZ)
321 
322 /*
323  * Ignore suspend events for this amount of time after a resume
324  */
325 #define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
326 
327 /*
328  * Maximum number of events stored
329  */
330 #define APM_MAX_EVENTS		20
331 
332 /*
333  * The per-file APM data
334  */
335 struct apm_user {
336 	int		magic;
337 	struct apm_user *next;
338 	unsigned int	suser: 1;
339 	unsigned int	writer: 1;
340 	unsigned int	reader: 1;
341 	unsigned int	suspend_wait: 1;
342 	int		suspend_result;
343 	int		suspends_pending;
344 	int		standbys_pending;
345 	int		suspends_read;
346 	int		standbys_read;
347 	int		event_head;
348 	int		event_tail;
349 	apm_event_t	events[APM_MAX_EVENTS];
350 };
351 
352 /*
353  * The magic number in apm_user
354  */
355 #define APM_BIOS_MAGIC		0x4101
356 
357 /*
358  * idle percentage above which bios idle calls are done
359  */
360 #ifdef CONFIG_APM_CPU_IDLE
361 #warning deprecated CONFIG_APM_CPU_IDLE will be deleted in 2012
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 bool debug __read_mostly;
386 static bool smp __read_mostly;
387 static int apm_disabled = -1;
388 #ifdef CONFIG_SMP
389 static bool power_off;
390 #else
391 static bool power_off = 1;
392 #endif
393 static bool realmode_power_off;
394 #ifdef CONFIG_APM_ALLOW_INTS
395 static bool allow_ints = 1;
396 #else
397 static bool allow_ints;
398 #endif
399 static bool broken_psr;
400 
401 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
402 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
403 static struct apm_user *user_list;
404 static DEFINE_SPINLOCK(user_list_lock);
405 static DEFINE_MUTEX(apm_mutex);
406 
407 /*
408  * Set up a segment that references the real mode segment 0x40
409  * that extends up to the end of page zero (that we have reserved).
410  * This is for buggy BIOS's that refer to (real mode) segment 0x40
411  * even though they are called in protected mode.
412  */
413 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
414 			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
415 
416 static const char driver_version[] = "1.16ac";	/* no spaces */
417 
418 static struct task_struct *kapmd_task;
419 
420 /*
421  *	APM event names taken from the APM 1.2 specification. These are
422  *	the message codes that the BIOS uses to tell us about events
423  */
424 static const char * const apm_event_name[] = {
425 	"system standby",
426 	"system suspend",
427 	"normal resume",
428 	"critical resume",
429 	"low battery",
430 	"power status change",
431 	"update time",
432 	"critical suspend",
433 	"user standby",
434 	"user suspend",
435 	"system standby resume",
436 	"capabilities change"
437 };
438 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
439 
440 typedef struct lookup_t {
441 	int	key;
442 	char 	*msg;
443 } lookup_t;
444 
445 /*
446  *	The BIOS returns a set of standard error codes in AX when the
447  *	carry flag is set.
448  */
449 
450 static const lookup_t error_table[] = {
451 /* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
452 	{ APM_DISABLED,		"Power management disabled" },
453 	{ APM_CONNECTED,	"Real mode interface already connected" },
454 	{ APM_NOT_CONNECTED,	"Interface not connected" },
455 	{ APM_16_CONNECTED,	"16 bit interface already connected" },
456 /* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
457 	{ APM_32_CONNECTED,	"32 bit interface already connected" },
458 	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
459 	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
460 	{ APM_BAD_PARAM,	"Parameter out of range" },
461 	{ APM_NOT_ENGAGED,	"Interface not engaged" },
462 	{ APM_BAD_FUNCTION,     "Function not supported" },
463 	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
464 	{ APM_BAD_STATE,	"Unable to enter requested state" },
465 /* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
466 	{ APM_NO_ERROR,		"BIOS did not set a return code" },
467 	{ APM_NOT_PRESENT,	"No APM present" }
468 };
469 #define ERROR_COUNT	ARRAY_SIZE(error_table)
470 
471 /**
472  *	apm_error	-	display an APM error
473  *	@str: information string
474  *	@err: APM BIOS return code
475  *
476  *	Write a meaningful log entry to the kernel log in the event of
477  *	an APM error.  Note that this also handles (negative) kernel errors.
478  */
479 
480 static void apm_error(char *str, int err)
481 {
482 	int i;
483 
484 	for (i = 0; i < ERROR_COUNT; i++)
485 		if (error_table[i].key == err)
486 			break;
487 	if (i < ERROR_COUNT)
488 		printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
489 	else if (err < 0)
490 		printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err);
491 	else
492 		printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
493 		       str, err);
494 }
495 
496 /*
497  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
498  * apm_info.allow_ints, we are being really paranoid here!  Not only
499  * are interrupts disabled, but all the segment registers (except SS)
500  * are saved and zeroed this means that if the BIOS tries to reference
501  * any data without explicitly loading the segment registers, the kernel
502  * will fault immediately rather than have some unforeseen circumstances
503  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
504  * this depends on CS referring to the same physical memory as DS so that
505  * DS can be zeroed before the call. Unfortunately, we can't do anything
506  * about the stack segment/pointer.  Also, we tell the compiler that
507  * everything could change.
508  *
509  * Also, we KNOW that for the non error case of apm_bios_call, there
510  * is no useful data returned in the low order 8 bits of eax.
511  */
512 
513 static inline unsigned long __apm_irq_save(void)
514 {
515 	unsigned long flags;
516 	local_save_flags(flags);
517 	if (apm_info.allow_ints) {
518 		if (irqs_disabled_flags(flags))
519 			local_irq_enable();
520 	} else
521 		local_irq_disable();
522 
523 	return flags;
524 }
525 
526 #define apm_irq_save(flags) \
527 	do { flags = __apm_irq_save(); } while (0)
528 
529 static inline void apm_irq_restore(unsigned long flags)
530 {
531 	if (irqs_disabled_flags(flags))
532 		local_irq_disable();
533 	else if (irqs_disabled())
534 		local_irq_enable();
535 }
536 
537 #ifdef APM_ZERO_SEGS
538 #	define APM_DECL_SEGS \
539 		unsigned int saved_fs; unsigned int saved_gs;
540 #	define APM_DO_SAVE_SEGS \
541 		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
542 #	define APM_DO_RESTORE_SEGS \
543 		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
544 #else
545 #	define APM_DECL_SEGS
546 #	define APM_DO_SAVE_SEGS
547 #	define APM_DO_RESTORE_SEGS
548 #endif
549 
550 struct apm_bios_call {
551 	u32 func;
552 	/* In and out */
553 	u32 ebx;
554 	u32 ecx;
555 	/* Out only */
556 	u32 eax;
557 	u32 edx;
558 	u32 esi;
559 
560 	/* Error: -ENOMEM, or bits 8-15 of eax */
561 	int err;
562 };
563 
564 /**
565  *	__apm_bios_call - Make an APM BIOS 32bit call
566  *	@_call: pointer to struct apm_bios_call.
567  *
568  *	Make an APM call using the 32bit protected mode interface. The
569  *	caller is responsible for knowing if APM BIOS is configured and
570  *	enabled. This call can disable interrupts for a long period of
571  *	time on some laptops.  The return value is in AH and the carry
572  *	flag is loaded into AL.  If there is an error, then the error
573  *	code is returned in AH (bits 8-15 of eax) and this function
574  *	returns non-zero.
575  *
576  *	Note: this makes the call on the current CPU.
577  */
578 static long __apm_bios_call(void *_call)
579 {
580 	APM_DECL_SEGS
581 	unsigned long		flags;
582 	int			cpu;
583 	struct desc_struct	save_desc_40;
584 	struct desc_struct	*gdt;
585 	struct apm_bios_call	*call = _call;
586 
587 	cpu = get_cpu();
588 	BUG_ON(cpu != 0);
589 	gdt = get_cpu_gdt_table(cpu);
590 	save_desc_40 = gdt[0x40 / 8];
591 	gdt[0x40 / 8] = bad_bios_desc;
592 
593 	apm_irq_save(flags);
594 	APM_DO_SAVE_SEGS;
595 	apm_bios_call_asm(call->func, call->ebx, call->ecx,
596 			  &call->eax, &call->ebx, &call->ecx, &call->edx,
597 			  &call->esi);
598 	APM_DO_RESTORE_SEGS;
599 	apm_irq_restore(flags);
600 	gdt[0x40 / 8] = save_desc_40;
601 	put_cpu();
602 
603 	return call->eax & 0xff;
604 }
605 
606 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
607 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
608 {
609 	int ret;
610 
611 	/* Don't bother with work_on_cpu in the common case, so we don't
612 	 * have to worry about OOM or overhead. */
613 	if (get_cpu() == 0) {
614 		ret = fn(call);
615 		put_cpu();
616 	} else {
617 		put_cpu();
618 		ret = work_on_cpu(0, fn, call);
619 	}
620 
621 	/* work_on_cpu can fail with -ENOMEM */
622 	if (ret < 0)
623 		call->err = ret;
624 	else
625 		call->err = (call->eax >> 8) & 0xff;
626 
627 	return ret;
628 }
629 
630 /**
631  *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
632  *	@call: the apm_bios_call registers.
633  *
634  *	If there is an error, it is returned in @call.err.
635  */
636 static int apm_bios_call(struct apm_bios_call *call)
637 {
638 	return on_cpu0(__apm_bios_call, call);
639 }
640 
641 /**
642  *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
643  *	@_call: pointer to struct apm_bios_call.
644  *
645  *	Make a BIOS call that returns one value only, or just status.
646  *	If there is an error, then the error code is returned in AH
647  *	(bits 8-15 of eax) and this function returns non-zero (it can
648  *	also return -ENOMEM). This is used for simpler BIOS operations.
649  *	This call may hold interrupts off for a long time on some laptops.
650  *
651  *	Note: this makes the call on the current CPU.
652  */
653 static long __apm_bios_call_simple(void *_call)
654 {
655 	u8			error;
656 	APM_DECL_SEGS
657 	unsigned long		flags;
658 	int			cpu;
659 	struct desc_struct	save_desc_40;
660 	struct desc_struct	*gdt;
661 	struct apm_bios_call	*call = _call;
662 
663 	cpu = get_cpu();
664 	BUG_ON(cpu != 0);
665 	gdt = get_cpu_gdt_table(cpu);
666 	save_desc_40 = gdt[0x40 / 8];
667 	gdt[0x40 / 8] = bad_bios_desc;
668 
669 	apm_irq_save(flags);
670 	APM_DO_SAVE_SEGS;
671 	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
672 					 &call->eax);
673 	APM_DO_RESTORE_SEGS;
674 	apm_irq_restore(flags);
675 	gdt[0x40 / 8] = save_desc_40;
676 	put_cpu();
677 	return error;
678 }
679 
680 /**
681  *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
682  *	@func: APM function to invoke
683  *	@ebx_in: EBX register value for BIOS call
684  *	@ecx_in: ECX register value for BIOS call
685  *	@eax: EAX register on return from the BIOS call
686  *	@err: bits
687  *
688  *	Make a BIOS call that returns one value only, or just status.
689  *	If there is an error, then the error code is returned in @err
690  *	and this function returns non-zero. This is used for simpler
691  *	BIOS operations.  This call may hold interrupts off for a long
692  *	time on some laptops.
693  */
694 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
695 				int *err)
696 {
697 	struct apm_bios_call call;
698 	int ret;
699 
700 	call.func = func;
701 	call.ebx = ebx_in;
702 	call.ecx = ecx_in;
703 
704 	ret = on_cpu0(__apm_bios_call_simple, &call);
705 	*eax = call.eax;
706 	*err = call.err;
707 	return ret;
708 }
709 
710 /**
711  *	apm_driver_version	-	APM driver version
712  *	@val:	loaded with the APM version on return
713  *
714  *	Retrieve the APM version supported by the BIOS. This is only
715  *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
716  *	probably present.
717  *
718  *	On entry val should point to a value indicating the APM driver
719  *	version with the high byte being the major and the low byte the
720  *	minor number both in BCD
721  *
722  *	On return it will hold the BIOS revision supported in the
723  *	same format.
724  */
725 
726 static int apm_driver_version(u_short *val)
727 {
728 	u32 eax;
729 	int err;
730 
731 	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
732 		return err;
733 	*val = eax;
734 	return APM_SUCCESS;
735 }
736 
737 /**
738  *	apm_get_event	-	get an APM event from the BIOS
739  *	@event: pointer to the event
740  *	@info: point to the event information
741  *
742  *	The APM BIOS provides a polled information for event
743  *	reporting. The BIOS expects to be polled at least every second
744  *	when events are pending. When a message is found the caller should
745  *	poll until no more messages are present.  However, this causes
746  *	problems on some laptops where a suspend event notification is
747  *	not cleared until it is acknowledged.
748  *
749  *	Additional information is returned in the info pointer, providing
750  *	that APM 1.2 is in use. If no messges are pending the value 0x80
751  *	is returned (No power management events pending).
752  */
753 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
754 {
755 	struct apm_bios_call call;
756 
757 	call.func = APM_FUNC_GET_EVENT;
758 	call.ebx = call.ecx = 0;
759 
760 	if (apm_bios_call(&call))
761 		return call.err;
762 
763 	*event = call.ebx;
764 	if (apm_info.connection_version < 0x0102)
765 		*info = ~0; /* indicate info not valid */
766 	else
767 		*info = call.ecx;
768 	return APM_SUCCESS;
769 }
770 
771 /**
772  *	set_power_state	-	set the power management state
773  *	@what: which items to transition
774  *	@state: state to transition to
775  *
776  *	Request an APM change of state for one or more system devices. The
777  *	processor state must be transitioned last of all. what holds the
778  *	class of device in the upper byte and the device number (0xFF for
779  *	all) for the object to be transitioned.
780  *
781  *	The state holds the state to transition to, which may in fact
782  *	be an acceptance of a BIOS requested state change.
783  */
784 
785 static int set_power_state(u_short what, u_short state)
786 {
787 	u32 eax;
788 	int err;
789 
790 	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
791 		return err;
792 	return APM_SUCCESS;
793 }
794 
795 /**
796  *	set_system_power_state - set system wide power state
797  *	@state: which state to enter
798  *
799  *	Transition the entire system into a new APM power state.
800  */
801 
802 static int set_system_power_state(u_short state)
803 {
804 	return set_power_state(APM_DEVICE_ALL, state);
805 }
806 
807 /**
808  *	apm_do_idle	-	perform power saving
809  *
810  *	This function notifies the BIOS that the processor is (in the view
811  *	of the OS) idle. It returns -1 in the event that the BIOS refuses
812  *	to handle the idle request. On a success the function returns 1
813  *	if the BIOS did clock slowing or 0 otherwise.
814  */
815 
816 static int apm_do_idle(void)
817 {
818 	u32 eax;
819 	u8 ret = 0;
820 	int idled = 0;
821 	int polling;
822 	int err = 0;
823 
824 	polling = !!(current_thread_info()->status & TS_POLLING);
825 	if (polling) {
826 		current_thread_info()->status &= ~TS_POLLING;
827 		/*
828 		 * TS_POLLING-cleared state must be visible before we
829 		 * test NEED_RESCHED:
830 		 */
831 		smp_mb();
832 	}
833 	if (!need_resched()) {
834 		idled = 1;
835 		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
836 	}
837 	if (polling)
838 		current_thread_info()->status |= TS_POLLING;
839 
840 	if (!idled)
841 		return 0;
842 
843 	if (ret) {
844 		static unsigned long t;
845 
846 		/* This always fails on some SMP boards running UP kernels.
847 		 * Only report the failure the first 5 times.
848 		 */
849 		if (++t < 5) {
850 			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
851 			t = jiffies;
852 		}
853 		return -1;
854 	}
855 	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
856 	return clock_slowed;
857 }
858 
859 /**
860  *	apm_do_busy	-	inform the BIOS the CPU is busy
861  *
862  *	Request that the BIOS brings the CPU back to full performance.
863  */
864 
865 static void apm_do_busy(void)
866 {
867 	u32 dummy;
868 	int err;
869 
870 	if (clock_slowed || ALWAYS_CALL_BUSY) {
871 		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
872 		clock_slowed = 0;
873 	}
874 }
875 
876 /*
877  * If no process has really been interested in
878  * the CPU for some time, we want to call BIOS
879  * power management - we probably want
880  * to conserve power.
881  */
882 #define IDLE_CALC_LIMIT	(HZ * 100)
883 #define IDLE_LEAKY_MAX	16
884 
885 static void (*original_pm_idle)(void) __read_mostly;
886 
887 /**
888  * apm_cpu_idle		-	cpu idling for APM capable Linux
889  *
890  * This is the idling function the kernel executes when APM is available. It
891  * tries to do BIOS powermanagement based on the average system idle time.
892  * Furthermore it calls the system default idle routine.
893  */
894 
895 static void apm_cpu_idle(void)
896 {
897 	static int use_apm_idle; /* = 0 */
898 	static unsigned int last_jiffies; /* = 0 */
899 	static unsigned int last_stime; /* = 0 */
900 
901 	int apm_idle_done = 0;
902 	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
903 	unsigned int bucket;
904 
905 	WARN_ONCE(1, "deprecated apm_cpu_idle will be deleted in 2012");
906 recalc:
907 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
908 		use_apm_idle = 0;
909 		last_jiffies = jiffies;
910 		last_stime = current->stime;
911 	} else if (jiffies_since_last_check > idle_period) {
912 		unsigned int idle_percentage;
913 
914 		idle_percentage = current->stime - last_stime;
915 		idle_percentage *= 100;
916 		idle_percentage /= jiffies_since_last_check;
917 		use_apm_idle = (idle_percentage > idle_threshold);
918 		if (apm_info.forbid_idle)
919 			use_apm_idle = 0;
920 		last_jiffies = jiffies;
921 		last_stime = current->stime;
922 	}
923 
924 	bucket = IDLE_LEAKY_MAX;
925 
926 	while (!need_resched()) {
927 		if (use_apm_idle) {
928 			unsigned int t;
929 
930 			t = jiffies;
931 			switch (apm_do_idle()) {
932 			case 0:
933 				apm_idle_done = 1;
934 				if (t != jiffies) {
935 					if (bucket) {
936 						bucket = IDLE_LEAKY_MAX;
937 						continue;
938 					}
939 				} else if (bucket) {
940 					bucket--;
941 					continue;
942 				}
943 				break;
944 			case 1:
945 				apm_idle_done = 1;
946 				break;
947 			default: /* BIOS refused */
948 				break;
949 			}
950 		}
951 		if (original_pm_idle)
952 			original_pm_idle();
953 		else
954 			default_idle();
955 		local_irq_disable();
956 		jiffies_since_last_check = jiffies - last_jiffies;
957 		if (jiffies_since_last_check > idle_period)
958 			goto recalc;
959 	}
960 
961 	if (apm_idle_done)
962 		apm_do_busy();
963 
964 	local_irq_enable();
965 }
966 
967 /**
968  *	apm_power_off	-	ask the BIOS to power off
969  *
970  *	Handle the power off sequence. This is the one piece of code we
971  *	will execute even on SMP machines. In order to deal with BIOS
972  *	bugs we support real mode APM BIOS power off calls. We also make
973  *	the SMP call on CPU0 as some systems will only honour this call
974  *	on their first cpu.
975  */
976 
977 static void apm_power_off(void)
978 {
979 	/* Some bioses don't like being called from CPU != 0 */
980 	if (apm_info.realmode_power_off) {
981 		set_cpus_allowed_ptr(current, cpumask_of(0));
982 		machine_real_restart(MRR_APM);
983 	} else {
984 		(void)set_system_power_state(APM_STATE_OFF);
985 	}
986 }
987 
988 #ifdef CONFIG_APM_DO_ENABLE
989 
990 /**
991  *	apm_enable_power_management - enable BIOS APM power management
992  *	@enable: enable yes/no
993  *
994  *	Enable or disable the APM BIOS power services.
995  */
996 
997 static int apm_enable_power_management(int enable)
998 {
999 	u32 eax;
1000 	int err;
1001 
1002 	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1003 		return APM_NOT_ENGAGED;
1004 	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1005 				 enable, &eax, &err))
1006 		return err;
1007 	if (enable)
1008 		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1009 	else
1010 		apm_info.bios.flags |= APM_BIOS_DISABLED;
1011 	return APM_SUCCESS;
1012 }
1013 #endif
1014 
1015 /**
1016  *	apm_get_power_status	-	get current power state
1017  *	@status: returned status
1018  *	@bat: battery info
1019  *	@life: estimated life
1020  *
1021  *	Obtain the current power status from the APM BIOS. We return a
1022  *	status which gives the rough battery status, and current power
1023  *	source. The bat value returned give an estimate as a percentage
1024  *	of life and a status value for the battery. The estimated life
1025  *	if reported is a lifetime in secodnds/minutes at current powwer
1026  *	consumption.
1027  */
1028 
1029 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1030 {
1031 	struct apm_bios_call call;
1032 
1033 	call.func = APM_FUNC_GET_STATUS;
1034 	call.ebx = APM_DEVICE_ALL;
1035 	call.ecx = 0;
1036 
1037 	if (apm_info.get_power_status_broken)
1038 		return APM_32_UNSUPPORTED;
1039 	if (apm_bios_call(&call))
1040 		return call.err;
1041 	*status = call.ebx;
1042 	*bat = call.ecx;
1043 	if (apm_info.get_power_status_swabinminutes) {
1044 		*life = swab16((u16)call.edx);
1045 		*life |= 0x8000;
1046 	} else
1047 		*life = call.edx;
1048 	return APM_SUCCESS;
1049 }
1050 
1051 #if 0
1052 static int apm_get_battery_status(u_short which, u_short *status,
1053 				  u_short *bat, u_short *life, u_short *nbat)
1054 {
1055 	u32 eax;
1056 	u32 ebx;
1057 	u32 ecx;
1058 	u32 edx;
1059 	u32 esi;
1060 
1061 	if (apm_info.connection_version < 0x0102) {
1062 		/* pretend we only have one battery. */
1063 		if (which != 1)
1064 			return APM_BAD_DEVICE;
1065 		*nbat = 1;
1066 		return apm_get_power_status(status, bat, life);
1067 	}
1068 
1069 	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1070 			  &ebx, &ecx, &edx, &esi))
1071 		return (eax >> 8) & 0xff;
1072 	*status = ebx;
1073 	*bat = ecx;
1074 	*life = edx;
1075 	*nbat = esi;
1076 	return APM_SUCCESS;
1077 }
1078 #endif
1079 
1080 /**
1081  *	apm_engage_power_management	-	enable PM on a device
1082  *	@device: identity of device
1083  *	@enable: on/off
1084  *
1085  *	Activate or deactive power management on either a specific device
1086  *	or the entire system (%APM_DEVICE_ALL).
1087  */
1088 
1089 static int apm_engage_power_management(u_short device, int enable)
1090 {
1091 	u32 eax;
1092 	int err;
1093 
1094 	if ((enable == 0) && (device == APM_DEVICE_ALL)
1095 	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1096 		return APM_DISABLED;
1097 	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1098 				 &eax, &err))
1099 		return err;
1100 	if (device == APM_DEVICE_ALL) {
1101 		if (enable)
1102 			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1103 		else
1104 			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1105 	}
1106 	return APM_SUCCESS;
1107 }
1108 
1109 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1110 
1111 /**
1112  *	apm_console_blank	-	blank the display
1113  *	@blank: on/off
1114  *
1115  *	Attempt to blank the console, firstly by blanking just video device
1116  *	zero, and if that fails (some BIOSes don't support it) then it blanks
1117  *	all video devices. Typically the BIOS will do laptop backlight and
1118  *	monitor powerdown for us.
1119  */
1120 
1121 static int apm_console_blank(int blank)
1122 {
1123 	int error = APM_NOT_ENGAGED; /* silence gcc */
1124 	int i;
1125 	u_short state;
1126 	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1127 
1128 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1129 
1130 	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1131 		error = set_power_state(dev[i], state);
1132 
1133 		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1134 			return 1;
1135 
1136 		if (error == APM_NOT_ENGAGED)
1137 			break;
1138 	}
1139 
1140 	if (error == APM_NOT_ENGAGED) {
1141 		static int tried;
1142 		int eng_error;
1143 		if (tried++ == 0) {
1144 			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1145 			if (eng_error) {
1146 				apm_error("set display", error);
1147 				apm_error("engage interface", eng_error);
1148 				return 0;
1149 			} else
1150 				return apm_console_blank(blank);
1151 		}
1152 	}
1153 	apm_error("set display", error);
1154 	return 0;
1155 }
1156 #endif
1157 
1158 static int queue_empty(struct apm_user *as)
1159 {
1160 	return as->event_head == as->event_tail;
1161 }
1162 
1163 static apm_event_t get_queued_event(struct apm_user *as)
1164 {
1165 	if (++as->event_tail >= APM_MAX_EVENTS)
1166 		as->event_tail = 0;
1167 	return as->events[as->event_tail];
1168 }
1169 
1170 static void queue_event(apm_event_t event, struct apm_user *sender)
1171 {
1172 	struct apm_user *as;
1173 
1174 	spin_lock(&user_list_lock);
1175 	if (user_list == NULL)
1176 		goto out;
1177 	for (as = user_list; as != NULL; as = as->next) {
1178 		if ((as == sender) || (!as->reader))
1179 			continue;
1180 		if (++as->event_head >= APM_MAX_EVENTS)
1181 			as->event_head = 0;
1182 
1183 		if (as->event_head == as->event_tail) {
1184 			static int notified;
1185 
1186 			if (notified++ == 0)
1187 			    printk(KERN_ERR "apm: an event queue overflowed\n");
1188 			if (++as->event_tail >= APM_MAX_EVENTS)
1189 				as->event_tail = 0;
1190 		}
1191 		as->events[as->event_head] = event;
1192 		if (!as->suser || !as->writer)
1193 			continue;
1194 		switch (event) {
1195 		case APM_SYS_SUSPEND:
1196 		case APM_USER_SUSPEND:
1197 			as->suspends_pending++;
1198 			suspends_pending++;
1199 			break;
1200 
1201 		case APM_SYS_STANDBY:
1202 		case APM_USER_STANDBY:
1203 			as->standbys_pending++;
1204 			standbys_pending++;
1205 			break;
1206 		}
1207 	}
1208 	wake_up_interruptible(&apm_waitqueue);
1209 out:
1210 	spin_unlock(&user_list_lock);
1211 }
1212 
1213 static void reinit_timer(void)
1214 {
1215 #ifdef INIT_TIMER_AFTER_SUSPEND
1216 	unsigned long flags;
1217 
1218 	raw_spin_lock_irqsave(&i8253_lock, flags);
1219 	/* set the clock to HZ */
1220 	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1221 	udelay(10);
1222 	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1223 	udelay(10);
1224 	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1225 	udelay(10);
1226 	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1227 #endif
1228 }
1229 
1230 static int suspend(int vetoable)
1231 {
1232 	int err;
1233 	struct apm_user	*as;
1234 
1235 	dpm_suspend_start(PMSG_SUSPEND);
1236 	dpm_suspend_end(PMSG_SUSPEND);
1237 
1238 	local_irq_disable();
1239 	syscore_suspend();
1240 
1241 	local_irq_enable();
1242 
1243 	save_processor_state();
1244 	err = set_system_power_state(APM_STATE_SUSPEND);
1245 	ignore_normal_resume = 1;
1246 	restore_processor_state();
1247 
1248 	local_irq_disable();
1249 	reinit_timer();
1250 
1251 	if (err == APM_NO_ERROR)
1252 		err = APM_SUCCESS;
1253 	if (err != APM_SUCCESS)
1254 		apm_error("suspend", err);
1255 	err = (err == APM_SUCCESS) ? 0 : -EIO;
1256 
1257 	syscore_resume();
1258 	local_irq_enable();
1259 
1260 	dpm_resume_start(PMSG_RESUME);
1261 	dpm_resume_end(PMSG_RESUME);
1262 
1263 	queue_event(APM_NORMAL_RESUME, NULL);
1264 	spin_lock(&user_list_lock);
1265 	for (as = user_list; as != NULL; as = as->next) {
1266 		as->suspend_wait = 0;
1267 		as->suspend_result = err;
1268 	}
1269 	spin_unlock(&user_list_lock);
1270 	wake_up_interruptible(&apm_suspend_waitqueue);
1271 	return err;
1272 }
1273 
1274 static void standby(void)
1275 {
1276 	int err;
1277 
1278 	dpm_suspend_end(PMSG_SUSPEND);
1279 
1280 	local_irq_disable();
1281 	syscore_suspend();
1282 	local_irq_enable();
1283 
1284 	err = set_system_power_state(APM_STATE_STANDBY);
1285 	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1286 		apm_error("standby", err);
1287 
1288 	local_irq_disable();
1289 	syscore_resume();
1290 	local_irq_enable();
1291 
1292 	dpm_resume_start(PMSG_RESUME);
1293 }
1294 
1295 static apm_event_t get_event(void)
1296 {
1297 	int error;
1298 	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1299 	apm_eventinfo_t	info;
1300 
1301 	static int notified;
1302 
1303 	/* we don't use the eventinfo */
1304 	error = apm_get_event(&event, &info);
1305 	if (error == APM_SUCCESS)
1306 		return event;
1307 
1308 	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1309 		apm_error("get_event", error);
1310 
1311 	return 0;
1312 }
1313 
1314 static void check_events(void)
1315 {
1316 	apm_event_t event;
1317 	static unsigned long last_resume;
1318 	static int ignore_bounce;
1319 
1320 	while ((event = get_event()) != 0) {
1321 		if (debug) {
1322 			if (event <= NR_APM_EVENT_NAME)
1323 				printk(KERN_DEBUG "apm: received %s notify\n",
1324 				       apm_event_name[event - 1]);
1325 			else
1326 				printk(KERN_DEBUG "apm: received unknown "
1327 				       "event 0x%02x\n", event);
1328 		}
1329 		if (ignore_bounce
1330 		    && (time_after(jiffies, last_resume + bounce_interval)))
1331 			ignore_bounce = 0;
1332 
1333 		switch (event) {
1334 		case APM_SYS_STANDBY:
1335 		case APM_USER_STANDBY:
1336 			queue_event(event, NULL);
1337 			if (standbys_pending <= 0)
1338 				standby();
1339 			break;
1340 
1341 		case APM_USER_SUSPEND:
1342 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1343 			if (apm_info.connection_version > 0x100)
1344 				set_system_power_state(APM_STATE_REJECT);
1345 			break;
1346 #endif
1347 		case APM_SYS_SUSPEND:
1348 			if (ignore_bounce) {
1349 				if (apm_info.connection_version > 0x100)
1350 					set_system_power_state(APM_STATE_REJECT);
1351 				break;
1352 			}
1353 			/*
1354 			 * If we are already processing a SUSPEND,
1355 			 * then further SUSPEND events from the BIOS
1356 			 * will be ignored.  We also return here to
1357 			 * cope with the fact that the Thinkpads keep
1358 			 * sending a SUSPEND event until something else
1359 			 * happens!
1360 			 */
1361 			if (ignore_sys_suspend)
1362 				return;
1363 			ignore_sys_suspend = 1;
1364 			queue_event(event, NULL);
1365 			if (suspends_pending <= 0)
1366 				(void) suspend(1);
1367 			break;
1368 
1369 		case APM_NORMAL_RESUME:
1370 		case APM_CRITICAL_RESUME:
1371 		case APM_STANDBY_RESUME:
1372 			ignore_sys_suspend = 0;
1373 			last_resume = jiffies;
1374 			ignore_bounce = 1;
1375 			if ((event != APM_NORMAL_RESUME)
1376 			    || (ignore_normal_resume == 0)) {
1377 				dpm_resume_end(PMSG_RESUME);
1378 				queue_event(event, NULL);
1379 			}
1380 			ignore_normal_resume = 0;
1381 			break;
1382 
1383 		case APM_CAPABILITY_CHANGE:
1384 		case APM_LOW_BATTERY:
1385 		case APM_POWER_STATUS_CHANGE:
1386 			queue_event(event, NULL);
1387 			/* If needed, notify drivers here */
1388 			break;
1389 
1390 		case APM_UPDATE_TIME:
1391 			break;
1392 
1393 		case APM_CRITICAL_SUSPEND:
1394 			/*
1395 			 * We are not allowed to reject a critical suspend.
1396 			 */
1397 			(void)suspend(0);
1398 			break;
1399 		}
1400 	}
1401 }
1402 
1403 static void apm_event_handler(void)
1404 {
1405 	static int pending_count = 4;
1406 	int err;
1407 
1408 	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1409 		if ((apm_info.connection_version > 0x100) &&
1410 		    (pending_count-- <= 0)) {
1411 			pending_count = 4;
1412 			if (debug)
1413 				printk(KERN_DEBUG "apm: setting state busy\n");
1414 			err = set_system_power_state(APM_STATE_BUSY);
1415 			if (err)
1416 				apm_error("busy", err);
1417 		}
1418 	} else
1419 		pending_count = 4;
1420 	check_events();
1421 }
1422 
1423 /*
1424  * This is the APM thread main loop.
1425  */
1426 
1427 static void apm_mainloop(void)
1428 {
1429 	DECLARE_WAITQUEUE(wait, current);
1430 
1431 	add_wait_queue(&apm_waitqueue, &wait);
1432 	set_current_state(TASK_INTERRUPTIBLE);
1433 	for (;;) {
1434 		schedule_timeout(APM_CHECK_TIMEOUT);
1435 		if (kthread_should_stop())
1436 			break;
1437 		/*
1438 		 * Ok, check all events, check for idle (and mark us sleeping
1439 		 * so as not to count towards the load average)..
1440 		 */
1441 		set_current_state(TASK_INTERRUPTIBLE);
1442 		apm_event_handler();
1443 	}
1444 	remove_wait_queue(&apm_waitqueue, &wait);
1445 }
1446 
1447 static int check_apm_user(struct apm_user *as, const char *func)
1448 {
1449 	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1450 		printk(KERN_ERR "apm: %s passed bad filp\n", func);
1451 		return 1;
1452 	}
1453 	return 0;
1454 }
1455 
1456 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1457 {
1458 	struct apm_user *as;
1459 	int i;
1460 	apm_event_t event;
1461 
1462 	as = fp->private_data;
1463 	if (check_apm_user(as, "read"))
1464 		return -EIO;
1465 	if ((int)count < sizeof(apm_event_t))
1466 		return -EINVAL;
1467 	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1468 		return -EAGAIN;
1469 	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1470 	i = count;
1471 	while ((i >= sizeof(event)) && !queue_empty(as)) {
1472 		event = get_queued_event(as);
1473 		if (copy_to_user(buf, &event, sizeof(event))) {
1474 			if (i < count)
1475 				break;
1476 			return -EFAULT;
1477 		}
1478 		switch (event) {
1479 		case APM_SYS_SUSPEND:
1480 		case APM_USER_SUSPEND:
1481 			as->suspends_read++;
1482 			break;
1483 
1484 		case APM_SYS_STANDBY:
1485 		case APM_USER_STANDBY:
1486 			as->standbys_read++;
1487 			break;
1488 		}
1489 		buf += sizeof(event);
1490 		i -= sizeof(event);
1491 	}
1492 	if (i < count)
1493 		return count - i;
1494 	if (signal_pending(current))
1495 		return -ERESTARTSYS;
1496 	return 0;
1497 }
1498 
1499 static unsigned int do_poll(struct file *fp, poll_table *wait)
1500 {
1501 	struct apm_user *as;
1502 
1503 	as = fp->private_data;
1504 	if (check_apm_user(as, "poll"))
1505 		return 0;
1506 	poll_wait(fp, &apm_waitqueue, wait);
1507 	if (!queue_empty(as))
1508 		return POLLIN | POLLRDNORM;
1509 	return 0;
1510 }
1511 
1512 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1513 {
1514 	struct apm_user *as;
1515 	int ret;
1516 
1517 	as = filp->private_data;
1518 	if (check_apm_user(as, "ioctl"))
1519 		return -EIO;
1520 	if (!as->suser || !as->writer)
1521 		return -EPERM;
1522 	switch (cmd) {
1523 	case APM_IOC_STANDBY:
1524 		mutex_lock(&apm_mutex);
1525 		if (as->standbys_read > 0) {
1526 			as->standbys_read--;
1527 			as->standbys_pending--;
1528 			standbys_pending--;
1529 		} else
1530 			queue_event(APM_USER_STANDBY, as);
1531 		if (standbys_pending <= 0)
1532 			standby();
1533 		mutex_unlock(&apm_mutex);
1534 		break;
1535 	case APM_IOC_SUSPEND:
1536 		mutex_lock(&apm_mutex);
1537 		if (as->suspends_read > 0) {
1538 			as->suspends_read--;
1539 			as->suspends_pending--;
1540 			suspends_pending--;
1541 		} else
1542 			queue_event(APM_USER_SUSPEND, as);
1543 		if (suspends_pending <= 0) {
1544 			ret = suspend(1);
1545 			mutex_unlock(&apm_mutex);
1546 		} else {
1547 			as->suspend_wait = 1;
1548 			mutex_unlock(&apm_mutex);
1549 			wait_event_interruptible(apm_suspend_waitqueue,
1550 					as->suspend_wait == 0);
1551 			ret = as->suspend_result;
1552 		}
1553 		return ret;
1554 	default:
1555 		return -ENOTTY;
1556 	}
1557 	return 0;
1558 }
1559 
1560 static int do_release(struct inode *inode, struct file *filp)
1561 {
1562 	struct apm_user *as;
1563 
1564 	as = filp->private_data;
1565 	if (check_apm_user(as, "release"))
1566 		return 0;
1567 	filp->private_data = NULL;
1568 	if (as->standbys_pending > 0) {
1569 		standbys_pending -= as->standbys_pending;
1570 		if (standbys_pending <= 0)
1571 			standby();
1572 	}
1573 	if (as->suspends_pending > 0) {
1574 		suspends_pending -= as->suspends_pending;
1575 		if (suspends_pending <= 0)
1576 			(void) suspend(1);
1577 	}
1578 	spin_lock(&user_list_lock);
1579 	if (user_list == as)
1580 		user_list = as->next;
1581 	else {
1582 		struct apm_user *as1;
1583 
1584 		for (as1 = user_list;
1585 		     (as1 != NULL) && (as1->next != as);
1586 		     as1 = as1->next)
1587 			;
1588 		if (as1 == NULL)
1589 			printk(KERN_ERR "apm: filp not in user list\n");
1590 		else
1591 			as1->next = as->next;
1592 	}
1593 	spin_unlock(&user_list_lock);
1594 	kfree(as);
1595 	return 0;
1596 }
1597 
1598 static int do_open(struct inode *inode, struct file *filp)
1599 {
1600 	struct apm_user *as;
1601 
1602 	as = kmalloc(sizeof(*as), GFP_KERNEL);
1603 	if (as == NULL) {
1604 		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1605 		       sizeof(*as));
1606 		return -ENOMEM;
1607 	}
1608 	as->magic = APM_BIOS_MAGIC;
1609 	as->event_tail = as->event_head = 0;
1610 	as->suspends_pending = as->standbys_pending = 0;
1611 	as->suspends_read = as->standbys_read = 0;
1612 	/*
1613 	 * XXX - this is a tiny bit broken, when we consider BSD
1614 	 * process accounting. If the device is opened by root, we
1615 	 * instantly flag that we used superuser privs. Who knows,
1616 	 * we might close the device immediately without doing a
1617 	 * privileged operation -- cevans
1618 	 */
1619 	as->suser = capable(CAP_SYS_ADMIN);
1620 	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1621 	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1622 	spin_lock(&user_list_lock);
1623 	as->next = user_list;
1624 	user_list = as;
1625 	spin_unlock(&user_list_lock);
1626 	filp->private_data = as;
1627 	return 0;
1628 }
1629 
1630 static int proc_apm_show(struct seq_file *m, void *v)
1631 {
1632 	unsigned short	bx;
1633 	unsigned short	cx;
1634 	unsigned short	dx;
1635 	int		error;
1636 	unsigned short  ac_line_status = 0xff;
1637 	unsigned short  battery_status = 0xff;
1638 	unsigned short  battery_flag   = 0xff;
1639 	int		percentage     = -1;
1640 	int             time_units     = -1;
1641 	char            *units         = "?";
1642 
1643 	if ((num_online_cpus() == 1) &&
1644 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1645 		ac_line_status = (bx >> 8) & 0xff;
1646 		battery_status = bx & 0xff;
1647 		if ((cx & 0xff) != 0xff)
1648 			percentage = cx & 0xff;
1649 
1650 		if (apm_info.connection_version > 0x100) {
1651 			battery_flag = (cx >> 8) & 0xff;
1652 			if (dx != 0xffff) {
1653 				units = (dx & 0x8000) ? "min" : "sec";
1654 				time_units = dx & 0x7fff;
1655 			}
1656 		}
1657 	}
1658 	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1659 	   from the Get Power Status (0x0a) call unless otherwise noted.
1660 
1661 	   0) Linux driver version (this will change if format changes)
1662 	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1663 	   2) APM flags from APM Installation Check (0x00):
1664 	      bit 0: APM_16_BIT_SUPPORT
1665 	      bit 1: APM_32_BIT_SUPPORT
1666 	      bit 2: APM_IDLE_SLOWS_CLOCK
1667 	      bit 3: APM_BIOS_DISABLED
1668 	      bit 4: APM_BIOS_DISENGAGED
1669 	   3) AC line status
1670 	      0x00: Off-line
1671 	      0x01: On-line
1672 	      0x02: On backup power (BIOS >= 1.1 only)
1673 	      0xff: Unknown
1674 	   4) Battery status
1675 	      0x00: High
1676 	      0x01: Low
1677 	      0x02: Critical
1678 	      0x03: Charging
1679 	      0x04: Selected battery not present (BIOS >= 1.2 only)
1680 	      0xff: Unknown
1681 	   5) Battery flag
1682 	      bit 0: High
1683 	      bit 1: Low
1684 	      bit 2: Critical
1685 	      bit 3: Charging
1686 	      bit 7: No system battery
1687 	      0xff: Unknown
1688 	   6) Remaining battery life (percentage of charge):
1689 	      0-100: valid
1690 	      -1: Unknown
1691 	   7) Remaining battery life (time units):
1692 	      Number of remaining minutes or seconds
1693 	      -1: Unknown
1694 	   8) min = minutes; sec = seconds */
1695 
1696 	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1697 		   driver_version,
1698 		   (apm_info.bios.version >> 8) & 0xff,
1699 		   apm_info.bios.version & 0xff,
1700 		   apm_info.bios.flags,
1701 		   ac_line_status,
1702 		   battery_status,
1703 		   battery_flag,
1704 		   percentage,
1705 		   time_units,
1706 		   units);
1707 	return 0;
1708 }
1709 
1710 static int proc_apm_open(struct inode *inode, struct file *file)
1711 {
1712 	return single_open(file, proc_apm_show, NULL);
1713 }
1714 
1715 static const struct file_operations apm_file_ops = {
1716 	.owner		= THIS_MODULE,
1717 	.open		= proc_apm_open,
1718 	.read		= seq_read,
1719 	.llseek		= seq_lseek,
1720 	.release	= single_release,
1721 };
1722 
1723 static int apm(void *unused)
1724 {
1725 	unsigned short	bx;
1726 	unsigned short	cx;
1727 	unsigned short	dx;
1728 	int		error;
1729 	char 		*power_stat;
1730 	char 		*bat_stat;
1731 
1732 	/* 2002/08/01 - WT
1733 	 * This is to avoid random crashes at boot time during initialization
1734 	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1735 	 * Some bioses don't like being called from CPU != 0.
1736 	 * Method suggested by Ingo Molnar.
1737 	 */
1738 	set_cpus_allowed_ptr(current, cpumask_of(0));
1739 	BUG_ON(smp_processor_id() != 0);
1740 
1741 	if (apm_info.connection_version == 0) {
1742 		apm_info.connection_version = apm_info.bios.version;
1743 		if (apm_info.connection_version > 0x100) {
1744 			/*
1745 			 * We only support BIOSs up to version 1.2
1746 			 */
1747 			if (apm_info.connection_version > 0x0102)
1748 				apm_info.connection_version = 0x0102;
1749 			error = apm_driver_version(&apm_info.connection_version);
1750 			if (error != APM_SUCCESS) {
1751 				apm_error("driver version", error);
1752 				/* Fall back to an APM 1.0 connection. */
1753 				apm_info.connection_version = 0x100;
1754 			}
1755 		}
1756 	}
1757 
1758 	if (debug)
1759 		printk(KERN_INFO "apm: Connection version %d.%d\n",
1760 			(apm_info.connection_version >> 8) & 0xff,
1761 			apm_info.connection_version & 0xff);
1762 
1763 #ifdef CONFIG_APM_DO_ENABLE
1764 	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1765 		/*
1766 		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1767 		 * is booted with PM disabled but not in the docking station.
1768 		 * Unfortunate ...
1769 		 */
1770 		error = apm_enable_power_management(1);
1771 		if (error) {
1772 			apm_error("enable power management", error);
1773 			return -1;
1774 		}
1775 	}
1776 #endif
1777 
1778 	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1779 	    && (apm_info.connection_version > 0x0100)) {
1780 		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1781 		if (error) {
1782 			apm_error("engage power management", error);
1783 			return -1;
1784 		}
1785 	}
1786 
1787 	if (debug && (num_online_cpus() == 1 || smp)) {
1788 		error = apm_get_power_status(&bx, &cx, &dx);
1789 		if (error)
1790 			printk(KERN_INFO "apm: power status not available\n");
1791 		else {
1792 			switch ((bx >> 8) & 0xff) {
1793 			case 0:
1794 				power_stat = "off line";
1795 				break;
1796 			case 1:
1797 				power_stat = "on line";
1798 				break;
1799 			case 2:
1800 				power_stat = "on backup power";
1801 				break;
1802 			default:
1803 				power_stat = "unknown";
1804 				break;
1805 			}
1806 			switch (bx & 0xff) {
1807 			case 0:
1808 				bat_stat = "high";
1809 				break;
1810 			case 1:
1811 				bat_stat = "low";
1812 				break;
1813 			case 2:
1814 				bat_stat = "critical";
1815 				break;
1816 			case 3:
1817 				bat_stat = "charging";
1818 				break;
1819 			default:
1820 				bat_stat = "unknown";
1821 				break;
1822 			}
1823 			printk(KERN_INFO
1824 			       "apm: AC %s, battery status %s, battery life ",
1825 			       power_stat, bat_stat);
1826 			if ((cx & 0xff) == 0xff)
1827 				printk("unknown\n");
1828 			else
1829 				printk("%d%%\n", cx & 0xff);
1830 			if (apm_info.connection_version > 0x100) {
1831 				printk(KERN_INFO
1832 				       "apm: battery flag 0x%02x, battery life ",
1833 				       (cx >> 8) & 0xff);
1834 				if (dx == 0xffff)
1835 					printk("unknown\n");
1836 				else
1837 					printk("%d %s\n", dx & 0x7fff,
1838 					       (dx & 0x8000) ?
1839 					       "minutes" : "seconds");
1840 			}
1841 		}
1842 	}
1843 
1844 	/* Install our power off handler.. */
1845 	if (power_off)
1846 		pm_power_off = apm_power_off;
1847 
1848 	if (num_online_cpus() == 1 || smp) {
1849 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1850 		console_blank_hook = apm_console_blank;
1851 #endif
1852 		apm_mainloop();
1853 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1854 		console_blank_hook = NULL;
1855 #endif
1856 	}
1857 
1858 	return 0;
1859 }
1860 
1861 #ifndef MODULE
1862 static int __init apm_setup(char *str)
1863 {
1864 	int invert;
1865 
1866 	while ((str != NULL) && (*str != '\0')) {
1867 		if (strncmp(str, "off", 3) == 0)
1868 			apm_disabled = 1;
1869 		if (strncmp(str, "on", 2) == 0)
1870 			apm_disabled = 0;
1871 		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1872 		    (strncmp(str, "bounce_interval=", 16) == 0))
1873 			bounce_interval = simple_strtol(str + 16, NULL, 0);
1874 		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1875 		    (strncmp(str, "idle_threshold=", 15) == 0))
1876 			idle_threshold = simple_strtol(str + 15, NULL, 0);
1877 		if ((strncmp(str, "idle-period=", 12) == 0) ||
1878 		    (strncmp(str, "idle_period=", 12) == 0))
1879 			idle_period = simple_strtol(str + 12, NULL, 0);
1880 		invert = (strncmp(str, "no-", 3) == 0) ||
1881 			(strncmp(str, "no_", 3) == 0);
1882 		if (invert)
1883 			str += 3;
1884 		if (strncmp(str, "debug", 5) == 0)
1885 			debug = !invert;
1886 		if ((strncmp(str, "power-off", 9) == 0) ||
1887 		    (strncmp(str, "power_off", 9) == 0))
1888 			power_off = !invert;
1889 		if (strncmp(str, "smp", 3) == 0) {
1890 			smp = !invert;
1891 			idle_threshold = 100;
1892 		}
1893 		if ((strncmp(str, "allow-ints", 10) == 0) ||
1894 		    (strncmp(str, "allow_ints", 10) == 0))
1895 			apm_info.allow_ints = !invert;
1896 		if ((strncmp(str, "broken-psr", 10) == 0) ||
1897 		    (strncmp(str, "broken_psr", 10) == 0))
1898 			apm_info.get_power_status_broken = !invert;
1899 		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1900 		    (strncmp(str, "realmode_power_off", 18) == 0))
1901 			apm_info.realmode_power_off = !invert;
1902 		str = strchr(str, ',');
1903 		if (str != NULL)
1904 			str += strspn(str, ", \t");
1905 	}
1906 	return 1;
1907 }
1908 
1909 __setup("apm=", apm_setup);
1910 #endif
1911 
1912 static const struct file_operations apm_bios_fops = {
1913 	.owner		= THIS_MODULE,
1914 	.read		= do_read,
1915 	.poll		= do_poll,
1916 	.unlocked_ioctl	= do_ioctl,
1917 	.open		= do_open,
1918 	.release	= do_release,
1919 	.llseek		= noop_llseek,
1920 };
1921 
1922 static struct miscdevice apm_device = {
1923 	APM_MINOR_DEV,
1924 	"apm_bios",
1925 	&apm_bios_fops
1926 };
1927 
1928 
1929 /* Simple "print if true" callback */
1930 static int __init print_if_true(const struct dmi_system_id *d)
1931 {
1932 	printk("%s\n", d->ident);
1933 	return 0;
1934 }
1935 
1936 /*
1937  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1938  * disabled before the suspend. Linux used to get terribly confused by that.
1939  */
1940 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1941 {
1942 	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1943 	       "workaround hopefully not needed.\n", d->ident);
1944 	return 0;
1945 }
1946 
1947 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1948 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1949 {
1950 	if (apm_info.realmode_power_off == 0) {
1951 		apm_info.realmode_power_off = 1;
1952 		printk(KERN_INFO "%s bios detected. "
1953 		       "Using realmode poweroff only.\n", d->ident);
1954 	}
1955 	return 0;
1956 }
1957 
1958 /* Some laptops require interrupts to be enabled during APM calls */
1959 static int __init set_apm_ints(const struct dmi_system_id *d)
1960 {
1961 	if (apm_info.allow_ints == 0) {
1962 		apm_info.allow_ints = 1;
1963 		printk(KERN_INFO "%s machine detected. "
1964 		       "Enabling interrupts during APM calls.\n", d->ident);
1965 	}
1966 	return 0;
1967 }
1968 
1969 /* Some APM bioses corrupt memory or just plain do not work */
1970 static int __init apm_is_horked(const struct dmi_system_id *d)
1971 {
1972 	if (apm_info.disabled == 0) {
1973 		apm_info.disabled = 1;
1974 		printk(KERN_INFO "%s machine detected. "
1975 		       "Disabling APM.\n", d->ident);
1976 	}
1977 	return 0;
1978 }
1979 
1980 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1981 {
1982 	if (apm_info.disabled == 0) {
1983 		apm_info.disabled = 1;
1984 		printk(KERN_INFO "%s machine detected. "
1985 		       "Disabling APM.\n", d->ident);
1986 		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1987 		printk(KERN_INFO "download from support.intel.com\n");
1988 	}
1989 	return 0;
1990 }
1991 
1992 /* Some APM bioses hang on APM idle calls */
1993 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1994 {
1995 	if (apm_info.forbid_idle == 0) {
1996 		apm_info.forbid_idle = 1;
1997 		printk(KERN_INFO "%s machine detected. "
1998 		       "Disabling APM idle calls.\n", d->ident);
1999 	}
2000 	return 0;
2001 }
2002 
2003 /*
2004  *  Check for clue free BIOS implementations who use
2005  *  the following QA technique
2006  *
2007  *      [ Write BIOS Code ]<------
2008  *               |                ^
2009  *      < Does it Compile >----N--
2010  *               |Y               ^
2011  *	< Does it Boot Win98 >-N--
2012  *               |Y
2013  *           [Ship It]
2014  *
2015  *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2016  *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2017  */
2018 static int __init broken_apm_power(const struct dmi_system_id *d)
2019 {
2020 	apm_info.get_power_status_broken = 1;
2021 	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2022 	       "disabling power status reporting.\n");
2023 	return 0;
2024 }
2025 
2026 /*
2027  * This bios swaps the APM minute reporting bytes over (Many sony laptops
2028  * have this problem).
2029  */
2030 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2031 {
2032 	apm_info.get_power_status_swabinminutes = 1;
2033 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2034 	       "in minutes and wrong byte order.\n");
2035 	return 0;
2036 }
2037 
2038 static struct dmi_system_id __initdata apm_dmi_table[] = {
2039 	{
2040 		print_if_true,
2041 		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2042 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2043 			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2044 	},
2045 	{	/* Handle problems with APM on the C600 */
2046 		broken_ps2_resume, "Dell Latitude C600",
2047 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2048 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2049 	},
2050 	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2051 		set_apm_ints, "Dell Latitude",
2052 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2053 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2054 	},
2055 	{	/* APM crashes */
2056 		apm_is_horked, "Dell Inspiron 2500",
2057 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2058 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2059 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2060 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2061 	},
2062 	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2063 		set_apm_ints, "Dell Inspiron", {
2064 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2065 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2066 	},
2067 	{	/* Handle problems with APM on Inspiron 5000e */
2068 		broken_apm_power, "Dell Inspiron 5000e",
2069 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2070 			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2071 			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2072 	},
2073 	{	/* Handle problems with APM on Inspiron 2500 */
2074 		broken_apm_power, "Dell Inspiron 2500",
2075 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2076 			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2077 			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2078 	},
2079 	{	/* APM crashes */
2080 		apm_is_horked, "Dell Dimension 4100",
2081 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2082 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2083 			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2084 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2085 	},
2086 	{	/* Allow interrupts during suspend on Compaq Laptops*/
2087 		set_apm_ints, "Compaq 12XL125",
2088 		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2089 			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2090 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2091 			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2092 	},
2093 	{	/* Allow interrupts during APM or the clock goes slow */
2094 		set_apm_ints, "ASUSTeK",
2095 		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2096 			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2097 	},
2098 	{	/* APM blows on shutdown */
2099 		apm_is_horked, "ABIT KX7-333[R]",
2100 		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2101 			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2102 	},
2103 	{	/* APM crashes */
2104 		apm_is_horked, "Trigem Delhi3",
2105 		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2106 			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2107 	},
2108 	{	/* APM crashes */
2109 		apm_is_horked, "Fujitsu-Siemens",
2110 		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2111 			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2112 	},
2113 	{	/* APM crashes */
2114 		apm_is_horked_d850md, "Intel D850MD",
2115 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2116 			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2117 	},
2118 	{	/* APM crashes */
2119 		apm_is_horked, "Intel D810EMO",
2120 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2121 			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2122 	},
2123 	{	/* APM crashes */
2124 		apm_is_horked, "Dell XPS-Z",
2125 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2126 			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2127 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2128 	},
2129 	{	/* APM crashes */
2130 		apm_is_horked, "Sharp PC-PJ/AX",
2131 		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2132 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2133 			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2134 			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2135 	},
2136 	{	/* APM crashes */
2137 		apm_is_horked, "Dell Inspiron 2500",
2138 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2139 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2140 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2141 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2142 	},
2143 	{	/* APM idle hangs */
2144 		apm_likes_to_melt, "Jabil AMD",
2145 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2146 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2147 	},
2148 	{	/* APM idle hangs */
2149 		apm_likes_to_melt, "AMI Bios",
2150 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2151 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2152 	},
2153 	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2154 		swab_apm_power_in_minutes, "Sony VAIO",
2155 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2156 			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2157 			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2158 	},
2159 	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2160 		swab_apm_power_in_minutes, "Sony VAIO",
2161 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162 			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2163 			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2164 	},
2165 	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2166 		swab_apm_power_in_minutes, "Sony VAIO",
2167 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168 			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2169 			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2170 	},
2171 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2172 		swab_apm_power_in_minutes, "Sony VAIO",
2173 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174 			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2175 			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
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, "WME01Z1"),
2181 			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2182 	},
2183 	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2184 		swab_apm_power_in_minutes, "Sony VAIO",
2185 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2186 			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2187 			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2188 	},
2189 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2190 		swab_apm_power_in_minutes, "Sony VAIO",
2191 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192 			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2193 			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
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, "R0203Z3"),
2199 			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2200 	},
2201 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2202 		swab_apm_power_in_minutes, "Sony VAIO",
2203 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204 			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2205 			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2206 	},
2207 	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2208 		swab_apm_power_in_minutes, "Sony VAIO",
2209 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210 			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2211 			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2212 	},
2213 
2214 	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2215 		swab_apm_power_in_minutes, "Sony VAIO",
2216 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2217 			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2218 			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2219 	},
2220 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2221 		swab_apm_power_in_minutes, "Sony VAIO",
2222 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2223 			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2224 			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
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, "WXPO1Z3"),
2230 			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2231 	},
2232 	{	/* broken PM poweroff bios */
2233 		set_realmode_power_off, "Award Software v4.60 PGMA",
2234 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2235 			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2236 			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2237 	},
2238 
2239 	/* Generic per vendor APM settings  */
2240 
2241 	{	/* Allow interrupts during suspend on IBM laptops */
2242 		set_apm_ints, "IBM",
2243 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2244 	},
2245 
2246 	{ }
2247 };
2248 
2249 /*
2250  * Just start the APM thread. We do NOT want to do APM BIOS
2251  * calls from anything but the APM thread, if for no other reason
2252  * than the fact that we don't trust the APM BIOS. This way,
2253  * most common APM BIOS problems that lead to protection errors
2254  * etc will have at least some level of being contained...
2255  *
2256  * In short, if something bad happens, at least we have a choice
2257  * of just killing the apm thread..
2258  */
2259 static int __init apm_init(void)
2260 {
2261 	struct desc_struct *gdt;
2262 	int err;
2263 
2264 	dmi_check_system(apm_dmi_table);
2265 
2266 	if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2267 		printk(KERN_INFO "apm: BIOS not found.\n");
2268 		return -ENODEV;
2269 	}
2270 	printk(KERN_INFO
2271 	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2272 	       ((apm_info.bios.version >> 8) & 0xff),
2273 	       (apm_info.bios.version & 0xff),
2274 	       apm_info.bios.flags,
2275 	       driver_version);
2276 	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2277 		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2278 		return -ENODEV;
2279 	}
2280 
2281 	if (allow_ints)
2282 		apm_info.allow_ints = 1;
2283 	if (broken_psr)
2284 		apm_info.get_power_status_broken = 1;
2285 	if (realmode_power_off)
2286 		apm_info.realmode_power_off = 1;
2287 	/* User can override, but default is to trust DMI */
2288 	if (apm_disabled != -1)
2289 		apm_info.disabled = apm_disabled;
2290 
2291 	/*
2292 	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2293 	 * but is reportedly a 1.0 BIOS.
2294 	 */
2295 	if (apm_info.bios.version == 0x001)
2296 		apm_info.bios.version = 0x100;
2297 
2298 	/* BIOS < 1.2 doesn't set cseg_16_len */
2299 	if (apm_info.bios.version < 0x102)
2300 		apm_info.bios.cseg_16_len = 0; /* 64k */
2301 
2302 	if (debug) {
2303 		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2304 			apm_info.bios.cseg, apm_info.bios.offset,
2305 			apm_info.bios.cseg_16, apm_info.bios.dseg);
2306 		if (apm_info.bios.version > 0x100)
2307 			printk(" cseg len %x, dseg len %x",
2308 				apm_info.bios.cseg_len,
2309 				apm_info.bios.dseg_len);
2310 		if (apm_info.bios.version > 0x101)
2311 			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2312 		printk("\n");
2313 	}
2314 
2315 	if (apm_info.disabled) {
2316 		printk(KERN_NOTICE "apm: disabled on user request.\n");
2317 		return -ENODEV;
2318 	}
2319 	if ((num_online_cpus() > 1) && !power_off && !smp) {
2320 		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2321 		apm_info.disabled = 1;
2322 		return -ENODEV;
2323 	}
2324 	if (!acpi_disabled) {
2325 		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2326 		apm_info.disabled = 1;
2327 		return -ENODEV;
2328 	}
2329 
2330 	/*
2331 	 * Set up the long jump entry point to the APM BIOS, which is called
2332 	 * from inline assembly.
2333 	 */
2334 	apm_bios_entry.offset = apm_info.bios.offset;
2335 	apm_bios_entry.segment = APM_CS;
2336 
2337 	/*
2338 	 * The APM 1.1 BIOS is supposed to provide limit information that it
2339 	 * recognizes.  Many machines do this correctly, but many others do
2340 	 * not restrict themselves to their claimed limit.  When this happens,
2341 	 * they will cause a segmentation violation in the kernel at boot time.
2342 	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2343 	 *
2344 	 * Note we only set APM segments on CPU zero, since we pin the APM
2345 	 * code to that CPU.
2346 	 */
2347 	gdt = get_cpu_gdt_table(0);
2348 	set_desc_base(&gdt[APM_CS >> 3],
2349 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2350 	set_desc_base(&gdt[APM_CS_16 >> 3],
2351 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2352 	set_desc_base(&gdt[APM_DS >> 3],
2353 		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2354 
2355 	proc_create("apm", 0, NULL, &apm_file_ops);
2356 
2357 	kapmd_task = kthread_create(apm, NULL, "kapmd");
2358 	if (IS_ERR(kapmd_task)) {
2359 		printk(KERN_ERR "apm: disabled - Unable to start kernel "
2360 				"thread.\n");
2361 		err = PTR_ERR(kapmd_task);
2362 		kapmd_task = NULL;
2363 		remove_proc_entry("apm", NULL);
2364 		return err;
2365 	}
2366 	wake_up_process(kapmd_task);
2367 
2368 	if (num_online_cpus() > 1 && !smp) {
2369 		printk(KERN_NOTICE
2370 		       "apm: disabled - APM is not SMP safe (power off active).\n");
2371 		return 0;
2372 	}
2373 
2374 	/*
2375 	 * Note we don't actually care if the misc_device cannot be registered.
2376 	 * this driver can do its job without it, even if userspace can't
2377 	 * control it.  just log the error
2378 	 */
2379 	if (misc_register(&apm_device))
2380 		printk(KERN_WARNING "apm: Could not register misc device.\n");
2381 
2382 	if (HZ != 100)
2383 		idle_period = (idle_period * HZ) / 100;
2384 	if (idle_threshold < 100) {
2385 		original_pm_idle = pm_idle;
2386 		pm_idle  = apm_cpu_idle;
2387 		set_pm_idle = 1;
2388 	}
2389 
2390 	return 0;
2391 }
2392 
2393 static void __exit apm_exit(void)
2394 {
2395 	int error;
2396 
2397 	if (set_pm_idle) {
2398 		pm_idle = original_pm_idle;
2399 		/*
2400 		 * We are about to unload the current idle thread pm callback
2401 		 * (pm_idle), Wait for all processors to update cached/local
2402 		 * copies of pm_idle before proceeding.
2403 		 */
2404 		kick_all_cpus_sync();
2405 	}
2406 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2407 	    && (apm_info.connection_version > 0x0100)) {
2408 		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2409 		if (error)
2410 			apm_error("disengage power management", error);
2411 	}
2412 	misc_deregister(&apm_device);
2413 	remove_proc_entry("apm", NULL);
2414 	if (power_off)
2415 		pm_power_off = NULL;
2416 	if (kapmd_task) {
2417 		kthread_stop(kapmd_task);
2418 		kapmd_task = NULL;
2419 	}
2420 }
2421 
2422 module_init(apm_init);
2423 module_exit(apm_exit);
2424 
2425 MODULE_AUTHOR("Stephen Rothwell");
2426 MODULE_DESCRIPTION("Advanced Power Management");
2427 MODULE_LICENSE("GPL");
2428 module_param(debug, bool, 0644);
2429 MODULE_PARM_DESC(debug, "Enable debug mode");
2430 module_param(power_off, bool, 0444);
2431 MODULE_PARM_DESC(power_off, "Enable power off");
2432 module_param(bounce_interval, int, 0444);
2433 MODULE_PARM_DESC(bounce_interval,
2434 		"Set the number of ticks to ignore suspend bounces");
2435 module_param(allow_ints, bool, 0444);
2436 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2437 module_param(broken_psr, bool, 0444);
2438 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2439 module_param(realmode_power_off, bool, 0444);
2440 MODULE_PARM_DESC(realmode_power_off,
2441 		"Switch to real mode before powering off");
2442 module_param(idle_threshold, int, 0444);
2443 MODULE_PARM_DESC(idle_threshold,
2444 	"System idle percentage above which to make APM BIOS idle calls");
2445 module_param(idle_period, int, 0444);
2446 MODULE_PARM_DESC(idle_period,
2447 	"Period (in sec/100) over which to caculate the idle percentage");
2448 module_param(smp, bool, 0444);
2449 MODULE_PARM_DESC(smp,
2450 	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2451 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2452