2 * APM BIOS driver for Linux
3 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
5 * Initial development of this driver was funded by NEC Australia P/L
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
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.
18 * October 1995, Rik Faith (faith@cs.unc.edu):
19 * Minor enhancements and updates (to the patch set) for 1.3.x
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)
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
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,
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 replacment 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
69 * 1.6: Cope with complier/assembler differences.
70 * Only try to turn off the first display device.
71 * Fix OOPS at power off with no APM BIOS by Jan Echternach
72 * <echter@informatik.uni-rostock.de>
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
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
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.
101 * 1.10: Fix for Thinkpad return code.
102 * Merge 2.2 and 2.3 drivers.
103 * Remove APM dependencies in arch/i386/kernel/process.c
104 * Remove APM dependencies in drivers/char/sysrq.c
105 * Reset time across standby.
106 * Allow more inititialisation on SMP.
107 * Remove CONFIG_APM_POWER_OFF and make it boot time
108 * configurable (default on).
109 * Make debug only a boot time parameter (remove APM_DEBUG).
110 * Try to blank all devices on any error.
111 * 1.11: Remove APM dependencies in drivers/char/console.c
112 * Check nr_running to detect if we are idle (from
113 * Borislav Deianov <borislav@lix.polytechnique.fr>)
114 * Fix for bioses that don't zero the top part of the
115 * entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
116 * (reported by Panos Katsaloulis <teras@writeme.com>).
117 * Real mode power off patch (Walter Hofmann
118 * <Walter.Hofmann@physik.stud.uni-erlangen.de>).
119 * 1.12: Remove CONFIG_SMP as the compiler will optimize
120 * the code away anyway (smp_num_cpus == 1 in UP)
121 * noted by Artur Skawina <skawina@geocities.com>.
122 * Make power off under SMP work again.
123 * Fix thinko with initial engaging of BIOS.
124 * Make sure power off only happens on CPU 0
125 * (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
126 * Do error notification to user mode if BIOS calls fail.
127 * Move entrypoint offset fix to ...boot/setup.S
128 * where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
129 * Remove smp-power-off. SMP users must now specify
130 * "apm=power-off" on the kernel command line. Suggested
131 * by Jim Avera <jima@hal.com>, modified by Alan Cox
132 * <alan@lxorguk.ukuu.org.uk>.
133 * Register the /proc/apm entry even on SMP so that
134 * scripts that check for it before doing power off
135 * work (Jim Avera <jima@hal.com>).
136 * 1.13: Changes for new pm_ interfaces (Andy Henroid
137 * <andy_henroid@yahoo.com>).
138 * Modularize the code.
139 * Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
140 * is now the way life works).
141 * Fix thinko in suspend() (wrong return).
142 * Notify drivers on critical suspend.
143 * Make kapmd absorb more idle time (Pavel Machek <pavel@suse.cz>
145 * Disable interrupts while we are suspended (Andy Henroid
146 * <andy_henroid@yahoo.com> fixed by sfr).
147 * Make power off work on SMP again (Tony Hoyle
148 * <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
149 * Remove CONFIG_APM_SUSPEND_BOUNCE. The bounce ignore
150 * interval is now configurable.
151 * 1.14: Make connection version persist across module unload/load.
152 * Enable and engage power management earlier.
153 * Disengage power management on module unload.
154 * Changed to use the sysrq-register hack for registering the
155 * power off function called by magic sysrq based upon discussions
156 * in irc://irc.openprojects.net/#kernelnewbies
157 * (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
158 * Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
159 * (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
160 * Work around byte swap bug in one of the Vaio's BIOS's
161 * (Marc Boucher <marc@mbsi.ca>).
162 * Exposed the disable flag to dmi so that we can handle known
163 * broken APM (Alan Cox <alan@redhat.com>).
164 * 1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165 * calling it - instead idle. (Alan Cox <alan@redhat.com>)
166 * If an APM idle fails log it and idle sensibly
167 * 1.15: Don't queue events to clients who open the device O_WRONLY.
168 * Don't expect replies from clients who open the device O_RDONLY.
169 * (Idea from Thomas Hood)
170 * Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
171 * 1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
172 * Notify listeners of standby or suspend events before notifying
173 * drivers. Return EBUSY to ioctl() if suspend is rejected.
174 * (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
175 * Ignore first resume after we generate our own resume event
176 * after a suspend (Thomas Hood)
177 * Daemonize now gets rid of our controlling terminal (sfr).
178 * CONFIG_APM_CPU_IDLE now just affects the default value of
179 * idle_threshold (sfr).
180 * Change name of kernel apm daemon (as it no longer idles) (sfr).
181 * 1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
182 * make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
183 * TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
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.
191 * [This document is available free from Intel by calling 800.628.8686 (fax
192 * 916.356.6100) or 800.548.4725; or via anonymous ftp from
193 * ftp://ftp.intel.com/pub/IAL/software_specs/apmv11.doc. It is also
194 * available from Microsoft by calling 206.882.8080.]
197 * Intel Corporation, Microsoft Corporation. Advanced Power Management
198 * (APM) BIOS Interface Specification, Revision 1.2, February 1996.
200 * [This document is available from Microsoft at:
201 * http://www.microsoft.com/hwdev/busbios/amp_12.htm]
204 #include <linux/module.h>
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/miscdevice.h>
215 #include <linux/apm_bios.h>
216 #include <linux/init.h>
217 #include <linux/time.h>
218 #include <linux/sched.h>
219 #include <linux/pm.h>
220 #include <linux/pm_legacy.h>
221 #include <linux/capability.h>
222 #include <linux/device.h>
223 #include <linux/kernel.h>
224 #include <linux/smp.h>
225 #include <linux/smp_lock.h>
226 #include <linux/dmi.h>
227 #include <linux/suspend.h>
229 #include <asm/system.h>
230 #include <asm/uaccess.h>
231 #include <asm/desc.h>
232 #include <asm/i8253.h>
234 #include "io_ports.h"
236 extern unsigned long get_cmos_time(void);
237 extern void machine_real_restart(unsigned char *, int);
239 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
240 extern int (*console_blank_hook)(int);
244 * The apm_bios device is one of the misc char devices.
245 * This is its minor number.
247 #define APM_MINOR_DEV 134
250 * See Documentation/Config.help for the configuration options.
252 * Various options can be changed at boot time as follows:
253 * (We allow underscores for compatibility with the modules code)
254 * apm=on/off enable/disable APM
255 * [no-]allow[-_]ints allow interrupts during BIOS calls
256 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
257 * [no-]realmode[-_]power[-_]off switch to real mode before
259 * [no-]debug log some debugging messages
260 * [no-]power[-_]off power off on shutdown
261 * [no-]smp Use apm even on an SMP box
262 * bounce[-_]interval=<n> number of ticks to ignore suspend
264 * idle[-_]threshold=<n> System idle percentage above which to
265 * make APM BIOS idle calls. Set it to
267 * idle[-_]period=<n> Period (in 1/100s of a second) over
268 * which the idle percentage is
272 /* KNOWN PROBLEM MACHINES:
274 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
275 * [Confirmed by TI representative]
276 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
277 * [Confirmed by BIOS disassembly]
278 * [This may work now ...]
279 * P: Toshiba 1950S: battery life information only gets updated after resume
280 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
281 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
282 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
283 * Neale Banks <neale@lowendale.com.au> December 2000
285 * Legend: U = unusable with APM patches
286 * P = partially usable with APM patches
290 * Define as 1 to make the driver always call the APM BIOS busy
291 * routine even if the clock was not reported as slowed by the
292 * idle routine. Otherwise, define as 0.
294 #define ALWAYS_CALL_BUSY 1
297 * Define to make the APM BIOS calls zero all data segment registers (so
298 * that an incorrect BIOS implementation will cause a kernel panic if it
299 * tries to write to arbitrary memory).
301 #define APM_ZERO_SEGS
306 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
307 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
308 * David Chen <chen@ctpa04.mit.edu>
310 #undef INIT_TIMER_AFTER_SUSPEND
312 #ifdef INIT_TIMER_AFTER_SUSPEND
313 #include <linux/timex.h>
315 #include <linux/delay.h>
319 * Need to poll the APM BIOS every second
321 #define APM_CHECK_TIMEOUT (HZ)
324 * Ignore suspend events for this amount of time after a resume
326 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
329 * Maximum number of events stored
331 #define APM_MAX_EVENTS 20
334 * The per-file APM data
338 struct apm_user * next;
339 unsigned int suser: 1;
340 unsigned int writer: 1;
341 unsigned int reader: 1;
342 unsigned int suspend_wait: 1;
344 int suspends_pending;
345 int standbys_pending;
350 apm_event_t events[APM_MAX_EVENTS];
354 * The magic number in apm_user
356 #define APM_BIOS_MAGIC 0x4101
359 * idle percentage above which bios idle calls are done
361 #ifdef CONFIG_APM_CPU_IDLE
362 #define DEFAULT_IDLE_THRESHOLD 95
364 #define DEFAULT_IDLE_THRESHOLD 100
366 #define DEFAULT_IDLE_PERIOD (100 / 3)
372 unsigned long offset;
373 unsigned short segment;
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;
385 #ifdef CONFIG_APM_RTC_IS_GMT
386 # define clock_cmos_diff 0
387 # define got_clock_diff 1
389 static long clock_cmos_diff;
390 static int got_clock_diff;
392 static int debug __read_mostly;
393 static int smp __read_mostly;
394 static int apm_disabled = -1;
396 static int power_off;
398 static int power_off = 1;
400 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
401 static int realmode_power_off = 1;
403 static int realmode_power_off;
405 static int exit_kapmd __read_mostly;
406 static int kapmd_running __read_mostly;
407 #ifdef CONFIG_APM_ALLOW_INTS
408 static int allow_ints = 1;
410 static int allow_ints;
412 static int broken_psr;
414 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
415 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
416 static struct apm_user * user_list;
417 static DEFINE_SPINLOCK(user_list_lock);
418 static const struct desc_struct bad_bios_desc = { 0, 0x00409200 };
420 static const char driver_version[] = "1.16ac"; /* no spaces */
423 * APM event names taken from the APM 1.2 specification. These are
424 * the message codes that the BIOS uses to tell us about events
426 static const char * const apm_event_name[] = {
432 "power status change",
437 "system standby resume",
438 "capabilities change"
440 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
442 typedef struct lookup_t {
448 * The BIOS returns a set of standard error codes in AX when the
452 static const lookup_t error_table[] = {
453 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
454 { APM_DISABLED, "Power management disabled" },
455 { APM_CONNECTED, "Real mode interface already connected" },
456 { APM_NOT_CONNECTED, "Interface not connected" },
457 { APM_16_CONNECTED, "16 bit interface already connected" },
458 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
459 { APM_32_CONNECTED, "32 bit interface already connected" },
460 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
461 { APM_BAD_DEVICE, "Unrecognized device ID" },
462 { APM_BAD_PARAM, "Parameter out of range" },
463 { APM_NOT_ENGAGED, "Interface not engaged" },
464 { APM_BAD_FUNCTION, "Function not supported" },
465 { APM_RESUME_DISABLED, "Resume timer disabled" },
466 { APM_BAD_STATE, "Unable to enter requested state" },
467 /* N/A { APM_NO_EVENTS, "No events pending" }, */
468 { APM_NO_ERROR, "BIOS did not set a return code" },
469 { APM_NOT_PRESENT, "No APM present" }
471 #define ERROR_COUNT ARRAY_SIZE(error_table)
474 * apm_error - display an APM error
475 * @str: information string
476 * @err: APM BIOS return code
478 * Write a meaningful log entry to the kernel log in the event of
482 static void apm_error(char *str, int err)
486 for (i = 0; i < ERROR_COUNT; i++)
487 if (error_table[i].key == err) break;
489 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
491 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
496 * Lock APM functionality to physical CPU 0
501 static cpumask_t apm_save_cpus(void)
503 cpumask_t x = current->cpus_allowed;
504 /* Some bioses don't like being called from CPU != 0 */
505 set_cpus_allowed(current, cpumask_of_cpu(0));
506 BUG_ON(smp_processor_id() != 0);
510 static inline void apm_restore_cpus(cpumask_t mask)
512 set_cpus_allowed(current, mask);
518 * No CPU lockdown needed on a uniprocessor
521 #define apm_save_cpus() (current->cpus_allowed)
522 #define apm_restore_cpus(x) (void)(x)
527 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
528 * apm_info.allow_ints, we are being really paranoid here! Not only
529 * are interrupts disabled, but all the segment registers (except SS)
530 * are saved and zeroed this means that if the BIOS tries to reference
531 * any data without explicitly loading the segment registers, the kernel
532 * will fault immediately rather than have some unforeseen circumstances
533 * for the rest of the kernel. And it will be very obvious! :-) Doing
534 * this depends on CS referring to the same physical memory as DS so that
535 * DS can be zeroed before the call. Unfortunately, we can't do anything
536 * about the stack segment/pointer. Also, we tell the compiler that
537 * everything could change.
539 * Also, we KNOW that for the non error case of apm_bios_call, there
540 * is no useful data returned in the low order 8 bits of eax.
544 if (apm_info.allow_ints) { \
545 if (irqs_disabled_flags(flags)) \
546 local_irq_enable(); \
548 local_irq_disable(); \
553 if (irqs_disabled_flags(flags)) \
554 local_irq_disable(); \
555 else if (irqs_disabled()) \
556 local_irq_enable(); \
560 # define APM_DECL_SEGS \
561 unsigned int saved_fs; unsigned int saved_gs;
562 # define APM_DO_SAVE_SEGS \
563 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
564 # define APM_DO_RESTORE_SEGS \
565 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
567 # define APM_DECL_SEGS
568 # define APM_DO_SAVE_SEGS
569 # define APM_DO_RESTORE_SEGS
573 * apm_bios_call - Make an APM BIOS 32bit call
574 * @func: APM function to execute
575 * @ebx_in: EBX register for call entry
576 * @ecx_in: ECX register for call entry
577 * @eax: EAX register return
578 * @ebx: EBX register return
579 * @ecx: ECX register return
580 * @edx: EDX register return
581 * @esi: ESI register return
583 * Make an APM call using the 32bit protected mode interface. The
584 * caller is responsible for knowing if APM BIOS is configured and
585 * enabled. This call can disable interrupts for a long period of
586 * time on some laptops. The return value is in AH and the carry
587 * flag is loaded into AL. If there is an error, then the error
588 * code is returned in AH (bits 8-15 of eax) and this function
592 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
593 u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
599 struct desc_struct save_desc_40;
600 struct desc_struct *gdt;
602 cpus = apm_save_cpus();
605 gdt = get_cpu_gdt_table(cpu);
606 save_desc_40 = gdt[0x40 / 8];
607 gdt[0x40 / 8] = bad_bios_desc;
609 local_save_flags(flags);
612 apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
615 gdt[0x40 / 8] = save_desc_40;
617 apm_restore_cpus(cpus);
623 * apm_bios_call_simple - make a simple APM BIOS 32bit call
624 * @func: APM function to invoke
625 * @ebx_in: EBX register value for BIOS call
626 * @ecx_in: ECX register value for BIOS call
627 * @eax: EAX register on return from the BIOS call
629 * Make a BIOS call that returns one value only, or just status.
630 * If there is an error, then the error code is returned in AH
631 * (bits 8-15 of eax) and this function returns non-zero. This is
632 * used for simpler BIOS operations. This call may hold interrupts
633 * off for a long time on some laptops.
636 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
643 struct desc_struct save_desc_40;
644 struct desc_struct *gdt;
646 cpus = apm_save_cpus();
649 gdt = get_cpu_gdt_table(cpu);
650 save_desc_40 = gdt[0x40 / 8];
651 gdt[0x40 / 8] = bad_bios_desc;
653 local_save_flags(flags);
656 error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
659 gdt[0x40 / 8] = save_desc_40;
661 apm_restore_cpus(cpus);
666 * apm_driver_version - APM driver version
667 * @val: loaded with the APM version on return
669 * Retrieve the APM version supported by the BIOS. This is only
670 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
673 * On entry val should point to a value indicating the APM driver
674 * version with the high byte being the major and the low byte the
675 * minor number both in BCD
677 * On return it will hold the BIOS revision supported in the
681 static int apm_driver_version(u_short *val)
685 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
686 return (eax >> 8) & 0xff;
692 * apm_get_event - get an APM event from the BIOS
693 * @event: pointer to the event
694 * @info: point to the event information
696 * The APM BIOS provides a polled information for event
697 * reporting. The BIOS expects to be polled at least every second
698 * when events are pending. When a message is found the caller should
699 * poll until no more messages are present. However, this causes
700 * problems on some laptops where a suspend event notification is
701 * not cleared until it is acknowledged.
703 * Additional information is returned in the info pointer, providing
704 * that APM 1.2 is in use. If no messges are pending the value 0x80
705 * is returned (No power management events pending).
708 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
715 if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
717 return (eax >> 8) & 0xff;
719 if (apm_info.connection_version < 0x0102)
720 *info = ~0; /* indicate info not valid */
727 * set_power_state - set the power management state
728 * @what: which items to transition
729 * @state: state to transition to
731 * Request an APM change of state for one or more system devices. The
732 * processor state must be transitioned last of all. what holds the
733 * class of device in the upper byte and the device number (0xFF for
734 * all) for the object to be transitioned.
736 * The state holds the state to transition to, which may in fact
737 * be an acceptance of a BIOS requested state change.
740 static int set_power_state(u_short what, u_short state)
744 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
745 return (eax >> 8) & 0xff;
750 * set_system_power_state - set system wide power state
751 * @state: which state to enter
753 * Transition the entire system into a new APM power state.
756 static int set_system_power_state(u_short state)
758 return set_power_state(APM_DEVICE_ALL, state);
762 * apm_do_idle - perform power saving
764 * This function notifies the BIOS that the processor is (in the view
765 * of the OS) idle. It returns -1 in the event that the BIOS refuses
766 * to handle the idle request. On a success the function returns 1
767 * if the BIOS did clock slowing or 0 otherwise.
770 static int apm_do_idle(void)
777 polling = !!(current_thread_info()->status & TS_POLLING);
779 current_thread_info()->status &= ~TS_POLLING;
780 smp_mb__after_clear_bit();
782 if (!need_resched()) {
784 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
787 current_thread_info()->status |= TS_POLLING;
793 static unsigned long t;
795 /* This always fails on some SMP boards running UP kernels.
796 * Only report the failure the first 5 times.
800 printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
806 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
811 * apm_do_busy - inform the BIOS the CPU is busy
813 * Request that the BIOS brings the CPU back to full performance.
816 static void apm_do_busy(void)
820 if (clock_slowed || ALWAYS_CALL_BUSY) {
821 (void) apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
827 * If no process has really been interested in
828 * the CPU for some time, we want to call BIOS
829 * power management - we probably want
832 #define IDLE_CALC_LIMIT (HZ * 100)
833 #define IDLE_LEAKY_MAX 16
835 static void (*original_pm_idle)(void) __read_mostly;
838 * apm_cpu_idle - cpu idling for APM capable Linux
840 * This is the idling function the kernel executes when APM is available. It
841 * tries to do BIOS powermanagement based on the average system idle time.
842 * Furthermore it calls the system default idle routine.
845 static void apm_cpu_idle(void)
847 static int use_apm_idle; /* = 0 */
848 static unsigned int last_jiffies; /* = 0 */
849 static unsigned int last_stime; /* = 0 */
851 int apm_idle_done = 0;
852 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
856 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
858 last_jiffies = jiffies;
859 last_stime = current->stime;
860 } else if (jiffies_since_last_check > idle_period) {
861 unsigned int idle_percentage;
863 idle_percentage = current->stime - last_stime;
864 idle_percentage *= 100;
865 idle_percentage /= jiffies_since_last_check;
866 use_apm_idle = (idle_percentage > idle_threshold);
867 if (apm_info.forbid_idle)
869 last_jiffies = jiffies;
870 last_stime = current->stime;
873 bucket = IDLE_LEAKY_MAX;
875 while (!need_resched()) {
880 switch (apm_do_idle()) {
881 case 0: apm_idle_done = 1;
884 bucket = IDLE_LEAKY_MAX;
892 case 1: apm_idle_done = 1;
894 default: /* BIOS refused */
898 if (original_pm_idle)
902 jiffies_since_last_check = jiffies - last_jiffies;
903 if (jiffies_since_last_check > idle_period)
912 * apm_power_off - ask the BIOS to power off
914 * Handle the power off sequence. This is the one piece of code we
915 * will execute even on SMP machines. In order to deal with BIOS
916 * bugs we support real mode APM BIOS power off calls. We also make
917 * the SMP call on CPU0 as some systems will only honour this call
918 * on their first cpu.
921 static void apm_power_off(void)
923 unsigned char po_bios_call[] = {
924 0xb8, 0x00, 0x10, /* movw $0x1000,ax */
925 0x8e, 0xd0, /* movw ax,ss */
926 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */
927 0xb8, 0x07, 0x53, /* movw $0x5307,ax */
928 0xbb, 0x01, 0x00, /* movw $0x0001,bx */
929 0xb9, 0x03, 0x00, /* movw $0x0003,cx */
930 0xcd, 0x15 /* int $0x15 */
933 /* Some bioses don't like being called from CPU != 0 */
934 if (apm_info.realmode_power_off)
936 (void)apm_save_cpus();
937 machine_real_restart(po_bios_call, sizeof(po_bios_call));
940 (void) set_system_power_state(APM_STATE_OFF);
943 #ifdef CONFIG_APM_DO_ENABLE
946 * apm_enable_power_management - enable BIOS APM power management
947 * @enable: enable yes/no
949 * Enable or disable the APM BIOS power services.
952 static int apm_enable_power_management(int enable)
956 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
957 return APM_NOT_ENGAGED;
958 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
960 return (eax >> 8) & 0xff;
962 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
964 apm_info.bios.flags |= APM_BIOS_DISABLED;
970 * apm_get_power_status - get current power state
971 * @status: returned status
973 * @life: estimated life
975 * Obtain the current power status from the APM BIOS. We return a
976 * status which gives the rough battery status, and current power
977 * source. The bat value returned give an estimate as a percentage
978 * of life and a status value for the battery. The estimated life
979 * if reported is a lifetime in secodnds/minutes at current powwer
983 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
991 if (apm_info.get_power_status_broken)
992 return APM_32_UNSUPPORTED;
993 if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
994 &eax, &ebx, &ecx, &edx, &dummy))
995 return (eax >> 8) & 0xff;
998 if (apm_info.get_power_status_swabinminutes) {
999 *life = swab16((u16)edx);
1007 static int apm_get_battery_status(u_short which, u_short *status,
1008 u_short *bat, u_short *life, u_short *nbat)
1016 if (apm_info.connection_version < 0x0102) {
1017 /* pretend we only have one battery. */
1019 return APM_BAD_DEVICE;
1021 return apm_get_power_status(status, bat, life);
1024 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1025 &ebx, &ecx, &edx, &esi))
1026 return (eax >> 8) & 0xff;
1036 * apm_engage_power_management - enable PM on a device
1037 * @device: identity of device
1040 * Activate or deactive power management on either a specific device
1041 * or the entire system (%APM_DEVICE_ALL).
1044 static int apm_engage_power_management(u_short device, int enable)
1048 if ((enable == 0) && (device == APM_DEVICE_ALL)
1049 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1050 return APM_DISABLED;
1051 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1052 return (eax >> 8) & 0xff;
1053 if (device == APM_DEVICE_ALL) {
1055 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1057 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1062 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1065 * apm_console_blank - blank the display
1068 * Attempt to blank the console, firstly by blanking just video device
1069 * zero, and if that fails (some BIOSes don't support it) then it blanks
1070 * all video devices. Typically the BIOS will do laptop backlight and
1071 * monitor powerdown for us.
1074 static int apm_console_blank(int blank)
1076 int error = APM_NOT_ENGAGED; /* silence gcc */
1079 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1081 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1083 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1084 error = set_power_state(dev[i], state);
1086 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1089 if (error == APM_NOT_ENGAGED)
1093 if (error == APM_NOT_ENGAGED) {
1097 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1099 apm_error("set display", error);
1100 apm_error("engage interface", eng_error);
1103 return apm_console_blank(blank);
1106 apm_error("set display", error);
1111 static int queue_empty(struct apm_user *as)
1113 return as->event_head == as->event_tail;
1116 static apm_event_t get_queued_event(struct apm_user *as)
1118 if (++as->event_tail >= APM_MAX_EVENTS)
1120 return as->events[as->event_tail];
1123 static void queue_event(apm_event_t event, struct apm_user *sender)
1125 struct apm_user * as;
1127 spin_lock(&user_list_lock);
1128 if (user_list == NULL)
1130 for (as = user_list; as != NULL; as = as->next) {
1131 if ((as == sender) || (!as->reader))
1133 if (++as->event_head >= APM_MAX_EVENTS)
1136 if (as->event_head == as->event_tail) {
1137 static int notified;
1139 if (notified++ == 0)
1140 printk(KERN_ERR "apm: an event queue overflowed\n");
1141 if (++as->event_tail >= APM_MAX_EVENTS)
1144 as->events[as->event_head] = event;
1145 if ((!as->suser) || (!as->writer))
1148 case APM_SYS_SUSPEND:
1149 case APM_USER_SUSPEND:
1150 as->suspends_pending++;
1154 case APM_SYS_STANDBY:
1155 case APM_USER_STANDBY:
1156 as->standbys_pending++;
1161 wake_up_interruptible(&apm_waitqueue);
1163 spin_unlock(&user_list_lock);
1166 static void set_time(void)
1168 if (got_clock_diff) { /* Must know time zone in order to set clock */
1169 xtime.tv_sec = get_cmos_time() + clock_cmos_diff;
1174 static void get_time_diff(void)
1176 #ifndef CONFIG_APM_RTC_IS_GMT
1178 * Estimate time zone so that set_time can update the clock
1180 clock_cmos_diff = -get_cmos_time();
1181 clock_cmos_diff += get_seconds();
1186 static void reinit_timer(void)
1188 #ifdef INIT_TIMER_AFTER_SUSPEND
1189 unsigned long flags;
1191 spin_lock_irqsave(&i8253_lock, flags);
1192 /* set the clock to 100 Hz */
1193 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1195 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1197 outb(LATCH >> 8, PIT_CH0); /* MSB */
1199 spin_unlock_irqrestore(&i8253_lock, flags);
1203 static int suspend(int vetoable)
1206 struct apm_user *as;
1208 if (pm_send_all(PM_SUSPEND, (void *)3)) {
1211 if (apm_info.connection_version > 0x100)
1212 set_system_power_state(APM_STATE_REJECT);
1214 ignore_sys_suspend = 0;
1215 printk(KERN_WARNING "apm: suspend was vetoed.\n");
1218 printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
1221 device_suspend(PMSG_SUSPEND);
1222 local_irq_disable();
1223 device_power_down(PMSG_SUSPEND);
1225 /* serialize with the timer interrupt */
1226 write_seqlock(&xtime_lock);
1228 /* protect against access to timer chip registers */
1229 spin_lock(&i8253_lock);
1233 * Irq spinlock must be dropped around set_system_power_state.
1234 * We'll undo any timer changes due to interrupts below.
1236 spin_unlock(&i8253_lock);
1237 write_sequnlock(&xtime_lock);
1240 save_processor_state();
1241 err = set_system_power_state(APM_STATE_SUSPEND);
1242 ignore_normal_resume = 1;
1243 restore_processor_state();
1245 local_irq_disable();
1246 write_seqlock(&xtime_lock);
1247 spin_lock(&i8253_lock);
1251 spin_unlock(&i8253_lock);
1252 write_sequnlock(&xtime_lock);
1254 if (err == APM_NO_ERROR)
1256 if (err != APM_SUCCESS)
1257 apm_error("suspend", err);
1258 err = (err == APM_SUCCESS) ? 0 : -EIO;
1262 pm_send_all(PM_RESUME, (void *)0);
1263 queue_event(APM_NORMAL_RESUME, NULL);
1265 spin_lock(&user_list_lock);
1266 for (as = user_list; as != NULL; as = as->next) {
1267 as->suspend_wait = 0;
1268 as->suspend_result = err;
1270 spin_unlock(&user_list_lock);
1271 wake_up_interruptible(&apm_suspend_waitqueue);
1275 static void standby(void)
1279 local_irq_disable();
1280 device_power_down(PMSG_SUSPEND);
1281 /* serialize with the timer interrupt */
1282 write_seqlock(&xtime_lock);
1283 /* If needed, notify drivers here */
1285 write_sequnlock(&xtime_lock);
1288 err = set_system_power_state(APM_STATE_STANDBY);
1289 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1290 apm_error("standby", err);
1292 local_irq_disable();
1297 static apm_event_t get_event(void)
1300 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1301 apm_eventinfo_t info;
1303 static int notified;
1305 /* we don't use the eventinfo */
1306 error = apm_get_event(&event, &info);
1307 if (error == APM_SUCCESS)
1310 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1311 apm_error("get_event", error);
1316 static void check_events(void)
1319 static unsigned long last_resume;
1320 static int ignore_bounce;
1322 while ((event = get_event()) != 0) {
1324 if (event <= NR_APM_EVENT_NAME)
1325 printk(KERN_DEBUG "apm: received %s notify\n",
1326 apm_event_name[event - 1]);
1328 printk(KERN_DEBUG "apm: received unknown "
1329 "event 0x%02x\n", event);
1332 && ((jiffies - last_resume) > bounce_interval))
1336 case APM_SYS_STANDBY:
1337 case APM_USER_STANDBY:
1338 queue_event(event, NULL);
1339 if (standbys_pending <= 0)
1343 case APM_USER_SUSPEND:
1344 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1345 if (apm_info.connection_version > 0x100)
1346 set_system_power_state(APM_STATE_REJECT);
1349 case APM_SYS_SUSPEND:
1350 if (ignore_bounce) {
1351 if (apm_info.connection_version > 0x100)
1352 set_system_power_state(APM_STATE_REJECT);
1356 * If we are already processing a SUSPEND,
1357 * then further SUSPEND events from the BIOS
1358 * will be ignored. We also return here to
1359 * cope with the fact that the Thinkpads keep
1360 * sending a SUSPEND event until something else
1363 if (ignore_sys_suspend)
1365 ignore_sys_suspend = 1;
1366 queue_event(event, NULL);
1367 if (suspends_pending <= 0)
1371 case APM_NORMAL_RESUME:
1372 case APM_CRITICAL_RESUME:
1373 case APM_STANDBY_RESUME:
1374 ignore_sys_suspend = 0;
1375 last_resume = jiffies;
1377 if ((event != APM_NORMAL_RESUME)
1378 || (ignore_normal_resume == 0)) {
1379 write_seqlock_irq(&xtime_lock);
1381 write_sequnlock_irq(&xtime_lock);
1383 pm_send_all(PM_RESUME, (void *)0);
1384 queue_event(event, NULL);
1386 ignore_normal_resume = 0;
1389 case APM_CAPABILITY_CHANGE:
1390 case APM_LOW_BATTERY:
1391 case APM_POWER_STATUS_CHANGE:
1392 queue_event(event, NULL);
1393 /* If needed, notify drivers here */
1396 case APM_UPDATE_TIME:
1397 write_seqlock_irq(&xtime_lock);
1399 write_sequnlock_irq(&xtime_lock);
1402 case APM_CRITICAL_SUSPEND:
1404 * We are not allowed to reject a critical suspend.
1412 static void apm_event_handler(void)
1414 static int pending_count = 4;
1417 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1418 if ((apm_info.connection_version > 0x100) &&
1419 (pending_count-- <= 0)) {
1422 printk(KERN_DEBUG "apm: setting state busy\n");
1423 err = set_system_power_state(APM_STATE_BUSY);
1425 apm_error("busy", err);
1433 * This is the APM thread main loop.
1436 static void apm_mainloop(void)
1438 DECLARE_WAITQUEUE(wait, current);
1440 add_wait_queue(&apm_waitqueue, &wait);
1441 set_current_state(TASK_INTERRUPTIBLE);
1443 schedule_timeout(APM_CHECK_TIMEOUT);
1447 * Ok, check all events, check for idle (and mark us sleeping
1448 * so as not to count towards the load average)..
1450 set_current_state(TASK_INTERRUPTIBLE);
1451 apm_event_handler();
1453 remove_wait_queue(&apm_waitqueue, &wait);
1456 static int check_apm_user(struct apm_user *as, const char *func)
1458 if ((as == NULL) || (as->magic != APM_BIOS_MAGIC)) {
1459 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1465 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1467 struct apm_user * as;
1471 as = fp->private_data;
1472 if (check_apm_user(as, "read"))
1474 if ((int)count < sizeof(apm_event_t))
1476 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1478 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1480 while ((i >= sizeof(event)) && !queue_empty(as)) {
1481 event = get_queued_event(as);
1482 if (copy_to_user(buf, &event, sizeof(event))) {
1488 case APM_SYS_SUSPEND:
1489 case APM_USER_SUSPEND:
1490 as->suspends_read++;
1493 case APM_SYS_STANDBY:
1494 case APM_USER_STANDBY:
1495 as->standbys_read++;
1498 buf += sizeof(event);
1503 if (signal_pending(current))
1504 return -ERESTARTSYS;
1508 static unsigned int do_poll(struct file *fp, poll_table * wait)
1510 struct apm_user * as;
1512 as = fp->private_data;
1513 if (check_apm_user(as, "poll"))
1515 poll_wait(fp, &apm_waitqueue, wait);
1516 if (!queue_empty(as))
1517 return POLLIN | POLLRDNORM;
1521 static int do_ioctl(struct inode * inode, struct file *filp,
1522 u_int cmd, u_long arg)
1524 struct apm_user * as;
1526 as = filp->private_data;
1527 if (check_apm_user(as, "ioctl"))
1529 if ((!as->suser) || (!as->writer))
1532 case APM_IOC_STANDBY:
1533 if (as->standbys_read > 0) {
1534 as->standbys_read--;
1535 as->standbys_pending--;
1538 queue_event(APM_USER_STANDBY, as);
1539 if (standbys_pending <= 0)
1542 case APM_IOC_SUSPEND:
1543 if (as->suspends_read > 0) {
1544 as->suspends_read--;
1545 as->suspends_pending--;
1548 queue_event(APM_USER_SUSPEND, as);
1549 if (suspends_pending <= 0) {
1552 as->suspend_wait = 1;
1553 wait_event_interruptible(apm_suspend_waitqueue,
1554 as->suspend_wait == 0);
1555 return as->suspend_result;
1564 static int do_release(struct inode * inode, struct file * filp)
1566 struct apm_user * as;
1568 as = filp->private_data;
1569 if (check_apm_user(as, "release"))
1571 filp->private_data = NULL;
1572 if (as->standbys_pending > 0) {
1573 standbys_pending -= as->standbys_pending;
1574 if (standbys_pending <= 0)
1577 if (as->suspends_pending > 0) {
1578 suspends_pending -= as->suspends_pending;
1579 if (suspends_pending <= 0)
1582 spin_lock(&user_list_lock);
1583 if (user_list == as)
1584 user_list = as->next;
1586 struct apm_user * as1;
1588 for (as1 = user_list;
1589 (as1 != NULL) && (as1->next != as);
1593 printk(KERN_ERR "apm: filp not in user list\n");
1595 as1->next = as->next;
1597 spin_unlock(&user_list_lock);
1602 static int do_open(struct inode * inode, struct file * filp)
1604 struct apm_user * as;
1606 as = (struct apm_user *)kmalloc(sizeof(*as), GFP_KERNEL);
1608 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1612 as->magic = APM_BIOS_MAGIC;
1613 as->event_tail = as->event_head = 0;
1614 as->suspends_pending = as->standbys_pending = 0;
1615 as->suspends_read = as->standbys_read = 0;
1617 * XXX - this is a tiny bit broken, when we consider BSD
1618 * process accounting. If the device is opened by root, we
1619 * instantly flag that we used superuser privs. Who knows,
1620 * we might close the device immediately without doing a
1621 * privileged operation -- cevans
1623 as->suser = capable(CAP_SYS_ADMIN);
1624 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1625 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1626 spin_lock(&user_list_lock);
1627 as->next = user_list;
1629 spin_unlock(&user_list_lock);
1630 filp->private_data = as;
1634 static int apm_get_info(char *buf, char **start, off_t fpos, int length)
1641 unsigned short ac_line_status = 0xff;
1642 unsigned short battery_status = 0xff;
1643 unsigned short battery_flag = 0xff;
1644 int percentage = -1;
1645 int time_units = -1;
1650 if ((num_online_cpus() == 1) &&
1651 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1652 ac_line_status = (bx >> 8) & 0xff;
1653 battery_status = bx & 0xff;
1654 if ((cx & 0xff) != 0xff)
1655 percentage = cx & 0xff;
1657 if (apm_info.connection_version > 0x100) {
1658 battery_flag = (cx >> 8) & 0xff;
1660 units = (dx & 0x8000) ? "min" : "sec";
1661 time_units = dx & 0x7fff;
1665 /* Arguments, with symbols from linux/apm_bios.h. Information is
1666 from the Get Power Status (0x0a) call unless otherwise noted.
1668 0) Linux driver version (this will change if format changes)
1669 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1670 2) APM flags from APM Installation Check (0x00):
1671 bit 0: APM_16_BIT_SUPPORT
1672 bit 1: APM_32_BIT_SUPPORT
1673 bit 2: APM_IDLE_SLOWS_CLOCK
1674 bit 3: APM_BIOS_DISABLED
1675 bit 4: APM_BIOS_DISENGAGED
1679 0x02: On backup power (BIOS >= 1.1 only)
1686 0x04: Selected battery not present (BIOS >= 1.2 only)
1693 bit 7: No system battery
1695 6) Remaining battery life (percentage of charge):
1698 7) Remaining battery life (time units):
1699 Number of remaining minutes or seconds
1701 8) min = minutes; sec = seconds */
1703 p += sprintf(p, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1705 (apm_info.bios.version >> 8) & 0xff,
1706 apm_info.bios.version & 0xff,
1707 apm_info.bios.flags,
1718 static int apm(void *unused)
1731 current->flags |= PF_NOFREEZE;
1735 * This is to avoid random crashes at boot time during initialization
1736 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1737 * Some bioses don't like being called from CPU != 0.
1738 * Method suggested by Ingo Molnar.
1740 set_cpus_allowed(current, cpumask_of_cpu(0));
1741 BUG_ON(smp_processor_id() != 0);
1744 if (apm_info.connection_version == 0) {
1745 apm_info.connection_version = apm_info.bios.version;
1746 if (apm_info.connection_version > 0x100) {
1748 * We only support BIOSs up to version 1.2
1750 if (apm_info.connection_version > 0x0102)
1751 apm_info.connection_version = 0x0102;
1752 error = apm_driver_version(&apm_info.connection_version);
1753 if (error != APM_SUCCESS) {
1754 apm_error("driver version", error);
1755 /* Fall back to an APM 1.0 connection. */
1756 apm_info.connection_version = 0x100;
1762 printk(KERN_INFO "apm: Connection version %d.%d\n",
1763 (apm_info.connection_version >> 8) & 0xff,
1764 apm_info.connection_version & 0xff);
1766 #ifdef CONFIG_APM_DO_ENABLE
1767 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1769 * This call causes my NEC UltraLite Versa 33/C to hang if it
1770 * is booted with PM disabled but not in the docking station.
1773 error = apm_enable_power_management(1);
1775 apm_error("enable power management", error);
1781 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1782 && (apm_info.connection_version > 0x0100)) {
1783 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1785 apm_error("engage power management", error);
1790 if (debug && (num_online_cpus() == 1 || smp )) {
1791 error = apm_get_power_status(&bx, &cx, &dx);
1793 printk(KERN_INFO "apm: power status not available\n");
1795 switch ((bx >> 8) & 0xff) {
1796 case 0: power_stat = "off line"; break;
1797 case 1: power_stat = "on line"; break;
1798 case 2: power_stat = "on backup power"; break;
1799 default: power_stat = "unknown"; break;
1801 switch (bx & 0xff) {
1802 case 0: bat_stat = "high"; break;
1803 case 1: bat_stat = "low"; break;
1804 case 2: bat_stat = "critical"; break;
1805 case 3: bat_stat = "charging"; break;
1806 default: bat_stat = "unknown"; break;
1809 "apm: AC %s, battery status %s, battery life ",
1810 power_stat, bat_stat);
1811 if ((cx & 0xff) == 0xff)
1812 printk("unknown\n");
1814 printk("%d%%\n", cx & 0xff);
1815 if (apm_info.connection_version > 0x100) {
1817 "apm: battery flag 0x%02x, battery life ",
1820 printk("unknown\n");
1822 printk("%d %s\n", dx & 0x7fff,
1824 "minutes" : "seconds");
1829 /* Install our power off handler.. */
1831 pm_power_off = apm_power_off;
1833 if (num_online_cpus() == 1 || smp) {
1834 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1835 console_blank_hook = apm_console_blank;
1838 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1839 console_blank_hook = NULL;
1848 static int __init apm_setup(char *str)
1852 while ((str != NULL) && (*str != '\0')) {
1853 if (strncmp(str, "off", 3) == 0)
1855 if (strncmp(str, "on", 2) == 0)
1857 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1858 (strncmp(str, "bounce_interval=", 16) == 0))
1859 bounce_interval = simple_strtol(str + 16, NULL, 0);
1860 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1861 (strncmp(str, "idle_threshold=", 15) == 0))
1862 idle_threshold = simple_strtol(str + 15, NULL, 0);
1863 if ((strncmp(str, "idle-period=", 12) == 0) ||
1864 (strncmp(str, "idle_period=", 12) == 0))
1865 idle_period = simple_strtol(str + 12, NULL, 0);
1866 invert = (strncmp(str, "no-", 3) == 0) ||
1867 (strncmp(str, "no_", 3) == 0);
1870 if (strncmp(str, "debug", 5) == 0)
1872 if ((strncmp(str, "power-off", 9) == 0) ||
1873 (strncmp(str, "power_off", 9) == 0))
1874 power_off = !invert;
1875 if (strncmp(str, "smp", 3) == 0)
1878 idle_threshold = 100;
1880 if ((strncmp(str, "allow-ints", 10) == 0) ||
1881 (strncmp(str, "allow_ints", 10) == 0))
1882 apm_info.allow_ints = !invert;
1883 if ((strncmp(str, "broken-psr", 10) == 0) ||
1884 (strncmp(str, "broken_psr", 10) == 0))
1885 apm_info.get_power_status_broken = !invert;
1886 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1887 (strncmp(str, "realmode_power_off", 18) == 0))
1888 apm_info.realmode_power_off = !invert;
1889 str = strchr(str, ',');
1891 str += strspn(str, ", \t");
1896 __setup("apm=", apm_setup);
1899 static struct file_operations apm_bios_fops = {
1900 .owner = THIS_MODULE,
1905 .release = do_release,
1908 static struct miscdevice apm_device = {
1915 /* Simple "print if true" callback */
1916 static int __init print_if_true(struct dmi_system_id *d)
1918 printk("%s\n", d->ident);
1923 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1924 * disabled before the suspend. Linux used to get terribly confused by that.
1926 static int __init broken_ps2_resume(struct dmi_system_id *d)
1928 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug workaround hopefully not needed.\n", d->ident);
1932 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1933 static int __init set_realmode_power_off(struct dmi_system_id *d)
1935 if (apm_info.realmode_power_off == 0) {
1936 apm_info.realmode_power_off = 1;
1937 printk(KERN_INFO "%s bios detected. Using realmode poweroff only.\n", d->ident);
1942 /* Some laptops require interrupts to be enabled during APM calls */
1943 static int __init set_apm_ints(struct dmi_system_id *d)
1945 if (apm_info.allow_ints == 0) {
1946 apm_info.allow_ints = 1;
1947 printk(KERN_INFO "%s machine detected. Enabling interrupts during APM calls.\n", d->ident);
1952 /* Some APM bioses corrupt memory or just plain do not work */
1953 static int __init apm_is_horked(struct dmi_system_id *d)
1955 if (apm_info.disabled == 0) {
1956 apm_info.disabled = 1;
1957 printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
1962 static int __init apm_is_horked_d850md(struct dmi_system_id *d)
1964 if (apm_info.disabled == 0) {
1965 apm_info.disabled = 1;
1966 printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
1967 printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
1968 printk(KERN_INFO "download from support.intel.com \n");
1973 /* Some APM bioses hang on APM idle calls */
1974 static int __init apm_likes_to_melt(struct dmi_system_id *d)
1976 if (apm_info.forbid_idle == 0) {
1977 apm_info.forbid_idle = 1;
1978 printk(KERN_INFO "%s machine detected. Disabling APM idle calls.\n", d->ident);
1984 * Check for clue free BIOS implementations who use
1985 * the following QA technique
1987 * [ Write BIOS Code ]<------
1989 * < Does it Compile >----N--
1991 * < Does it Boot Win98 >-N--
1995 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
1996 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
1998 static int __init broken_apm_power(struct dmi_system_id *d)
2000 apm_info.get_power_status_broken = 1;
2001 printk(KERN_WARNING "BIOS strings suggest APM bugs, disabling power status reporting.\n");
2006 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2007 * have this problem).
2009 static int __init swab_apm_power_in_minutes(struct dmi_system_id *d)
2011 apm_info.get_power_status_swabinminutes = 1;
2012 printk(KERN_WARNING "BIOS strings suggest APM reports battery life in minutes and wrong byte order.\n");
2016 static struct dmi_system_id __initdata apm_dmi_table[] = {
2019 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2020 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2021 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2023 { /* Handle problems with APM on the C600 */
2024 broken_ps2_resume, "Dell Latitude C600",
2025 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2026 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2028 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2029 set_apm_ints, "Dell Latitude",
2030 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2031 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2034 apm_is_horked, "Dell Inspiron 2500",
2035 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2036 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2037 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
2038 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2040 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2041 set_apm_ints, "Dell Inspiron", {
2042 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2043 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2045 { /* Handle problems with APM on Inspiron 5000e */
2046 broken_apm_power, "Dell Inspiron 5000e",
2047 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2048 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2049 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2051 { /* Handle problems with APM on Inspiron 2500 */
2052 broken_apm_power, "Dell Inspiron 2500",
2053 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2054 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2055 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2058 apm_is_horked, "Dell Dimension 4100",
2059 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2060 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2061 DMI_MATCH(DMI_BIOS_VENDOR,"Intel Corp."),
2062 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2064 { /* Allow interrupts during suspend on Compaq Laptops*/
2065 set_apm_ints, "Compaq 12XL125",
2066 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2067 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2068 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2069 DMI_MATCH(DMI_BIOS_VERSION,"4.06"), },
2071 { /* Allow interrupts during APM or the clock goes slow */
2072 set_apm_ints, "ASUSTeK",
2073 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2074 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2076 { /* APM blows on shutdown */
2077 apm_is_horked, "ABIT KX7-333[R]",
2078 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2079 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2082 apm_is_horked, "Trigem Delhi3",
2083 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2084 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2087 apm_is_horked, "Fujitsu-Siemens",
2088 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2089 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2092 apm_is_horked_d850md, "Intel D850MD",
2093 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2094 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2097 apm_is_horked, "Intel D810EMO",
2098 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2099 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2102 apm_is_horked, "Dell XPS-Z",
2103 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2104 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2105 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2108 apm_is_horked, "Sharp PC-PJ/AX",
2109 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2110 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2111 DMI_MATCH(DMI_BIOS_VENDOR,"SystemSoft"),
2112 DMI_MATCH(DMI_BIOS_VERSION,"Version R2.08"), },
2115 apm_is_horked, "Dell Inspiron 2500",
2116 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2117 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2118 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
2119 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2121 { /* APM idle hangs */
2122 apm_likes_to_melt, "Jabil AMD",
2123 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2124 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2126 { /* APM idle hangs */
2127 apm_likes_to_melt, "AMI Bios",
2128 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2129 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2131 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2132 swab_apm_power_in_minutes, "Sony VAIO",
2133 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2134 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2135 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2137 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2138 swab_apm_power_in_minutes, "Sony VAIO",
2139 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2140 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2141 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2143 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2144 swab_apm_power_in_minutes, "Sony VAIO",
2145 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2146 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2147 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2149 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2150 swab_apm_power_in_minutes, "Sony VAIO",
2151 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2152 DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2153 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2155 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2156 swab_apm_power_in_minutes, "Sony VAIO",
2157 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2158 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2159 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2161 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2162 swab_apm_power_in_minutes, "Sony VAIO",
2163 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2164 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2165 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2167 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2168 swab_apm_power_in_minutes, "Sony VAIO",
2169 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2170 DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2171 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2173 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2174 swab_apm_power_in_minutes, "Sony VAIO",
2175 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2176 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2177 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2179 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2180 swab_apm_power_in_minutes, "Sony VAIO",
2181 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2182 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2183 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2185 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2186 swab_apm_power_in_minutes, "Sony VAIO",
2187 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2188 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2189 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2192 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2193 swab_apm_power_in_minutes, "Sony VAIO",
2194 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2195 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2196 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2198 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2199 swab_apm_power_in_minutes, "Sony VAIO",
2200 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2201 DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2202 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2204 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2205 swab_apm_power_in_minutes, "Sony VAIO",
2206 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2207 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2208 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2210 { /* broken PM poweroff bios */
2211 set_realmode_power_off, "Award Software v4.60 PGMA",
2212 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2213 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2214 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2217 /* Generic per vendor APM settings */
2219 { /* Allow interrupts during suspend on IBM laptops */
2220 set_apm_ints, "IBM",
2221 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2228 * Just start the APM thread. We do NOT want to do APM BIOS
2229 * calls from anything but the APM thread, if for no other reason
2230 * than the fact that we don't trust the APM BIOS. This way,
2231 * most common APM BIOS problems that lead to protection errors
2232 * etc will have at least some level of being contained...
2234 * In short, if something bad happens, at least we have a choice
2235 * of just killing the apm thread..
2237 static int __init apm_init(void)
2239 struct proc_dir_entry *apm_proc;
2240 struct desc_struct *gdt;
2243 dmi_check_system(apm_dmi_table);
2245 if (apm_info.bios.version == 0) {
2246 printk(KERN_INFO "apm: BIOS not found.\n");
2250 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2251 ((apm_info.bios.version >> 8) & 0xff),
2252 (apm_info.bios.version & 0xff),
2253 apm_info.bios.flags,
2255 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2256 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2261 apm_info.allow_ints = 1;
2263 apm_info.get_power_status_broken = 1;
2264 if (realmode_power_off)
2265 apm_info.realmode_power_off = 1;
2266 /* User can override, but default is to trust DMI */
2267 if (apm_disabled != -1)
2268 apm_info.disabled = apm_disabled;
2271 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2272 * but is reportedly a 1.0 BIOS.
2274 if (apm_info.bios.version == 0x001)
2275 apm_info.bios.version = 0x100;
2277 /* BIOS < 1.2 doesn't set cseg_16_len */
2278 if (apm_info.bios.version < 0x102)
2279 apm_info.bios.cseg_16_len = 0; /* 64k */
2282 printk(KERN_INFO "apm: entry %x:%lx cseg16 %x dseg %x",
2283 apm_info.bios.cseg, apm_info.bios.offset,
2284 apm_info.bios.cseg_16, apm_info.bios.dseg);
2285 if (apm_info.bios.version > 0x100)
2286 printk(" cseg len %x, dseg len %x",
2287 apm_info.bios.cseg_len,
2288 apm_info.bios.dseg_len);
2289 if (apm_info.bios.version > 0x101)
2290 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2294 if (apm_info.disabled) {
2295 printk(KERN_NOTICE "apm: disabled on user request.\n");
2298 if ((num_online_cpus() > 1) && !power_off && !smp) {
2299 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2300 apm_info.disabled = 1;
2303 if (PM_IS_ACTIVE()) {
2304 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2305 apm_info.disabled = 1;
2308 #ifdef CONFIG_PM_LEGACY
2313 * Set up a segment that references the real mode segment 0x40
2314 * that extends up to the end of page zero (that we have reserved).
2315 * This is for buggy BIOS's that refer to (real mode) segment 0x40
2316 * even though they are called in protected mode.
2318 set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2319 _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2322 * Set up the long jump entry point to the APM BIOS, which is called
2323 * from inline assembly.
2325 apm_bios_entry.offset = apm_info.bios.offset;
2326 apm_bios_entry.segment = APM_CS;
2329 * The APM 1.1 BIOS is supposed to provide limit information that it
2330 * recognizes. Many machines do this correctly, but many others do
2331 * not restrict themselves to their claimed limit. When this happens,
2332 * they will cause a segmentation violation in the kernel at boot time.
2333 * Most BIOS's, however, will respect a 64k limit, so we use that.
2335 * Note we only set APM segments on CPU zero, since we pin the APM
2338 gdt = get_cpu_gdt_table(0);
2339 set_base(gdt[APM_CS >> 3],
2340 __va((unsigned long)apm_info.bios.cseg << 4));
2341 set_base(gdt[APM_CS_16 >> 3],
2342 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2343 set_base(gdt[APM_DS >> 3],
2344 __va((unsigned long)apm_info.bios.dseg << 4));
2346 apm_proc = create_proc_info_entry("apm", 0, NULL, apm_get_info);
2348 apm_proc->owner = THIS_MODULE;
2350 ret = kernel_thread(apm, NULL, CLONE_KERNEL | SIGCHLD);
2352 printk(KERN_ERR "apm: disabled - Unable to start kernel thread.\n");
2356 if (num_online_cpus() > 1 && !smp ) {
2358 "apm: disabled - APM is not SMP safe (power off active).\n");
2362 misc_register(&apm_device);
2365 idle_period = (idle_period * HZ) / 100;
2366 if (idle_threshold < 100) {
2367 original_pm_idle = pm_idle;
2368 pm_idle = apm_cpu_idle;
2375 static void __exit apm_exit(void)
2380 pm_idle = original_pm_idle;
2382 * We are about to unload the current idle thread pm callback
2383 * (pm_idle), Wait for all processors to update cached/local
2384 * copies of pm_idle before proceeding.
2388 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2389 && (apm_info.connection_version > 0x0100)) {
2390 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2392 apm_error("disengage power management", error);
2394 misc_deregister(&apm_device);
2395 remove_proc_entry("apm", NULL);
2397 pm_power_off = NULL;
2399 while (kapmd_running)
2401 #ifdef CONFIG_PM_LEGACY
2406 module_init(apm_init);
2407 module_exit(apm_exit);
2409 MODULE_AUTHOR("Stephen Rothwell");
2410 MODULE_DESCRIPTION("Advanced Power Management");
2411 MODULE_LICENSE("GPL");
2412 module_param(debug, bool, 0644);
2413 MODULE_PARM_DESC(debug, "Enable debug mode");
2414 module_param(power_off, bool, 0444);
2415 MODULE_PARM_DESC(power_off, "Enable power off");
2416 module_param(bounce_interval, int, 0444);
2417 MODULE_PARM_DESC(bounce_interval,
2418 "Set the number of ticks to ignore suspend bounces");
2419 module_param(allow_ints, bool, 0444);
2420 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2421 module_param(broken_psr, bool, 0444);
2422 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2423 module_param(realmode_power_off, bool, 0444);
2424 MODULE_PARM_DESC(realmode_power_off,
2425 "Switch to real mode before powering off");
2426 module_param(idle_threshold, int, 0444);
2427 MODULE_PARM_DESC(idle_threshold,
2428 "System idle percentage above which to make APM BIOS idle calls");
2429 module_param(idle_period, int, 0444);
2430 MODULE_PARM_DESC(idle_period,
2431 "Period (in sec/100) over which to caculate the idle percentage");
2432 module_param(smp, bool, 0444);
2433 MODULE_PARM_DESC(smp,
2434 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2435 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);