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>
228 #include <linux/kthread.h>
230 #include <asm/system.h>
231 #include <asm/uaccess.h>
232 #include <asm/desc.h>
233 #include <asm/i8253.h>
235 #include "io_ports.h"
237 extern unsigned long get_cmos_time(void);
238 extern void machine_real_restart(unsigned char *, int);
240 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
241 extern int (*console_blank_hook)(int);
245 * The apm_bios device is one of the misc char devices.
246 * This is its minor number.
248 #define APM_MINOR_DEV 134
251 * See Documentation/Config.help for the configuration options.
253 * Various options can be changed at boot time as follows:
254 * (We allow underscores for compatibility with the modules code)
255 * apm=on/off enable/disable APM
256 * [no-]allow[-_]ints allow interrupts during BIOS calls
257 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
258 * [no-]realmode[-_]power[-_]off switch to real mode before
260 * [no-]debug log some debugging messages
261 * [no-]power[-_]off power off on shutdown
262 * [no-]smp Use apm even on an SMP box
263 * bounce[-_]interval=<n> number of ticks to ignore suspend
265 * idle[-_]threshold=<n> System idle percentage above which to
266 * make APM BIOS idle calls. Set it to
268 * idle[-_]period=<n> Period (in 1/100s of a second) over
269 * which the idle percentage is
273 /* KNOWN PROBLEM MACHINES:
275 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
276 * [Confirmed by TI representative]
277 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
278 * [Confirmed by BIOS disassembly]
279 * [This may work now ...]
280 * P: Toshiba 1950S: battery life information only gets updated after resume
281 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
282 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
283 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
284 * Neale Banks <neale@lowendale.com.au> December 2000
286 * Legend: U = unusable with APM patches
287 * P = partially usable with APM patches
291 * Define as 1 to make the driver always call the APM BIOS busy
292 * routine even if the clock was not reported as slowed by the
293 * idle routine. Otherwise, define as 0.
295 #define ALWAYS_CALL_BUSY 1
298 * Define to make the APM BIOS calls zero all data segment registers (so
299 * that an incorrect BIOS implementation will cause a kernel panic if it
300 * tries to write to arbitrary memory).
302 #define APM_ZERO_SEGS
307 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
308 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
309 * David Chen <chen@ctpa04.mit.edu>
311 #undef INIT_TIMER_AFTER_SUSPEND
313 #ifdef INIT_TIMER_AFTER_SUSPEND
314 #include <linux/timex.h>
316 #include <linux/delay.h>
320 * Need to poll the APM BIOS every second
322 #define APM_CHECK_TIMEOUT (HZ)
325 * Ignore suspend events for this amount of time after a resume
327 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
330 * Maximum number of events stored
332 #define APM_MAX_EVENTS 20
335 * The per-file APM data
339 struct apm_user * next;
340 unsigned int suser: 1;
341 unsigned int writer: 1;
342 unsigned int reader: 1;
343 unsigned int suspend_wait: 1;
345 int suspends_pending;
346 int standbys_pending;
351 apm_event_t events[APM_MAX_EVENTS];
355 * The magic number in apm_user
357 #define APM_BIOS_MAGIC 0x4101
360 * idle percentage above which bios idle calls are done
362 #ifdef CONFIG_APM_CPU_IDLE
363 #define DEFAULT_IDLE_THRESHOLD 95
365 #define DEFAULT_IDLE_THRESHOLD 100
367 #define DEFAULT_IDLE_PERIOD (100 / 3)
373 unsigned long offset;
374 unsigned short segment;
376 static int clock_slowed;
377 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
378 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
379 static int set_pm_idle;
380 static int suspends_pending;
381 static int standbys_pending;
382 static int ignore_sys_suspend;
383 static int ignore_normal_resume;
384 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
386 #ifdef CONFIG_APM_RTC_IS_GMT
387 # define clock_cmos_diff 0
388 # define got_clock_diff 1
390 static long clock_cmos_diff;
391 static int got_clock_diff;
393 static int debug __read_mostly;
394 static int smp __read_mostly;
395 static int apm_disabled = -1;
397 static int power_off;
399 static int power_off = 1;
401 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
402 static int realmode_power_off = 1;
404 static int realmode_power_off;
406 #ifdef CONFIG_APM_ALLOW_INTS
407 static int allow_ints = 1;
409 static int allow_ints;
411 static int broken_psr;
413 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
414 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
415 static struct apm_user * user_list;
416 static DEFINE_SPINLOCK(user_list_lock);
417 static const struct desc_struct bad_bios_desc = { 0, 0x00409200 };
419 static const char driver_version[] = "1.16ac"; /* no spaces */
421 static struct task_struct *kapmd_task;
424 * APM event names taken from the APM 1.2 specification. These are
425 * the message codes that the BIOS uses to tell us about events
427 static const char * const apm_event_name[] = {
433 "power status change",
438 "system standby resume",
439 "capabilities change"
441 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
443 typedef struct lookup_t {
449 * The BIOS returns a set of standard error codes in AX when the
453 static const lookup_t error_table[] = {
454 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
455 { APM_DISABLED, "Power management disabled" },
456 { APM_CONNECTED, "Real mode interface already connected" },
457 { APM_NOT_CONNECTED, "Interface not connected" },
458 { APM_16_CONNECTED, "16 bit interface already connected" },
459 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
460 { APM_32_CONNECTED, "32 bit interface already connected" },
461 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
462 { APM_BAD_DEVICE, "Unrecognized device ID" },
463 { APM_BAD_PARAM, "Parameter out of range" },
464 { APM_NOT_ENGAGED, "Interface not engaged" },
465 { APM_BAD_FUNCTION, "Function not supported" },
466 { APM_RESUME_DISABLED, "Resume timer disabled" },
467 { APM_BAD_STATE, "Unable to enter requested state" },
468 /* N/A { APM_NO_EVENTS, "No events pending" }, */
469 { APM_NO_ERROR, "BIOS did not set a return code" },
470 { APM_NOT_PRESENT, "No APM present" }
472 #define ERROR_COUNT ARRAY_SIZE(error_table)
475 * apm_error - display an APM error
476 * @str: information string
477 * @err: APM BIOS return code
479 * Write a meaningful log entry to the kernel log in the event of
483 static void apm_error(char *str, int err)
487 for (i = 0; i < ERROR_COUNT; i++)
488 if (error_table[i].key == err) break;
490 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
492 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
497 * Lock APM functionality to physical CPU 0
502 static cpumask_t apm_save_cpus(void)
504 cpumask_t x = current->cpus_allowed;
505 /* Some bioses don't like being called from CPU != 0 */
506 set_cpus_allowed(current, cpumask_of_cpu(0));
507 BUG_ON(smp_processor_id() != 0);
511 static inline void apm_restore_cpus(cpumask_t mask)
513 set_cpus_allowed(current, mask);
519 * No CPU lockdown needed on a uniprocessor
522 #define apm_save_cpus() (current->cpus_allowed)
523 #define apm_restore_cpus(x) (void)(x)
528 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
529 * apm_info.allow_ints, we are being really paranoid here! Not only
530 * are interrupts disabled, but all the segment registers (except SS)
531 * are saved and zeroed this means that if the BIOS tries to reference
532 * any data without explicitly loading the segment registers, the kernel
533 * will fault immediately rather than have some unforeseen circumstances
534 * for the rest of the kernel. And it will be very obvious! :-) Doing
535 * this depends on CS referring to the same physical memory as DS so that
536 * DS can be zeroed before the call. Unfortunately, we can't do anything
537 * about the stack segment/pointer. Also, we tell the compiler that
538 * everything could change.
540 * Also, we KNOW that for the non error case of apm_bios_call, there
541 * is no useful data returned in the low order 8 bits of eax.
544 if (apm_info.allow_ints) \
545 local_irq_enable(); \
550 # define APM_DECL_SEGS \
551 unsigned int saved_fs; unsigned int saved_gs;
552 # define APM_DO_SAVE_SEGS \
553 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
554 # define APM_DO_RESTORE_SEGS \
555 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
557 # define APM_DECL_SEGS
558 # define APM_DO_SAVE_SEGS
559 # define APM_DO_RESTORE_SEGS
563 * apm_bios_call - Make an APM BIOS 32bit call
564 * @func: APM function to execute
565 * @ebx_in: EBX register for call entry
566 * @ecx_in: ECX register for call entry
567 * @eax: EAX register return
568 * @ebx: EBX register return
569 * @ecx: ECX register return
570 * @edx: EDX register return
571 * @esi: ESI register return
573 * Make an APM call using the 32bit protected mode interface. The
574 * caller is responsible for knowing if APM BIOS is configured and
575 * enabled. This call can disable interrupts for a long period of
576 * time on some laptops. The return value is in AH and the carry
577 * flag is loaded into AL. If there is an error, then the error
578 * code is returned in AH (bits 8-15 of eax) and this function
582 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
583 u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
589 struct desc_struct save_desc_40;
590 struct desc_struct *gdt;
592 cpus = apm_save_cpus();
595 gdt = get_cpu_gdt_table(cpu);
596 save_desc_40 = gdt[0x40 / 8];
597 gdt[0x40 / 8] = bad_bios_desc;
599 local_save_flags(flags);
602 apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
604 local_irq_restore(flags);
605 gdt[0x40 / 8] = save_desc_40;
607 apm_restore_cpus(cpus);
613 * apm_bios_call_simple - make a simple APM BIOS 32bit call
614 * @func: APM function to invoke
615 * @ebx_in: EBX register value for BIOS call
616 * @ecx_in: ECX register value for BIOS call
617 * @eax: EAX register on return from the BIOS call
619 * Make a BIOS call that returns one value only, or just status.
620 * If there is an error, then the error code is returned in AH
621 * (bits 8-15 of eax) and this function returns non-zero. This is
622 * used for simpler BIOS operations. This call may hold interrupts
623 * off for a long time on some laptops.
626 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
633 struct desc_struct save_desc_40;
634 struct desc_struct *gdt;
636 cpus = apm_save_cpus();
639 gdt = get_cpu_gdt_table(cpu);
640 save_desc_40 = gdt[0x40 / 8];
641 gdt[0x40 / 8] = bad_bios_desc;
643 local_save_flags(flags);
646 error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
648 local_irq_restore(flags);
649 gdt[0x40 / 8] = save_desc_40;
651 apm_restore_cpus(cpus);
656 * apm_driver_version - APM driver version
657 * @val: loaded with the APM version on return
659 * Retrieve the APM version supported by the BIOS. This is only
660 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
663 * On entry val should point to a value indicating the APM driver
664 * version with the high byte being the major and the low byte the
665 * minor number both in BCD
667 * On return it will hold the BIOS revision supported in the
671 static int apm_driver_version(u_short *val)
675 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
676 return (eax >> 8) & 0xff;
682 * apm_get_event - get an APM event from the BIOS
683 * @event: pointer to the event
684 * @info: point to the event information
686 * The APM BIOS provides a polled information for event
687 * reporting. The BIOS expects to be polled at least every second
688 * when events are pending. When a message is found the caller should
689 * poll until no more messages are present. However, this causes
690 * problems on some laptops where a suspend event notification is
691 * not cleared until it is acknowledged.
693 * Additional information is returned in the info pointer, providing
694 * that APM 1.2 is in use. If no messges are pending the value 0x80
695 * is returned (No power management events pending).
698 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
705 if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
707 return (eax >> 8) & 0xff;
709 if (apm_info.connection_version < 0x0102)
710 *info = ~0; /* indicate info not valid */
717 * set_power_state - set the power management state
718 * @what: which items to transition
719 * @state: state to transition to
721 * Request an APM change of state for one or more system devices. The
722 * processor state must be transitioned last of all. what holds the
723 * class of device in the upper byte and the device number (0xFF for
724 * all) for the object to be transitioned.
726 * The state holds the state to transition to, which may in fact
727 * be an acceptance of a BIOS requested state change.
730 static int set_power_state(u_short what, u_short state)
734 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
735 return (eax >> 8) & 0xff;
740 * set_system_power_state - set system wide power state
741 * @state: which state to enter
743 * Transition the entire system into a new APM power state.
746 static int set_system_power_state(u_short state)
748 return set_power_state(APM_DEVICE_ALL, state);
752 * apm_do_idle - perform power saving
754 * This function notifies the BIOS that the processor is (in the view
755 * of the OS) idle. It returns -1 in the event that the BIOS refuses
756 * to handle the idle request. On a success the function returns 1
757 * if the BIOS did clock slowing or 0 otherwise.
760 static int apm_do_idle(void)
767 polling = !!(current_thread_info()->status & TS_POLLING);
769 current_thread_info()->status &= ~TS_POLLING;
770 smp_mb__after_clear_bit();
772 if (!need_resched()) {
774 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
777 current_thread_info()->status |= TS_POLLING;
783 static unsigned long t;
785 /* This always fails on some SMP boards running UP kernels.
786 * Only report the failure the first 5 times.
790 printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
796 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
801 * apm_do_busy - inform the BIOS the CPU is busy
803 * Request that the BIOS brings the CPU back to full performance.
806 static void apm_do_busy(void)
810 if (clock_slowed || ALWAYS_CALL_BUSY) {
811 (void) apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
817 * If no process has really been interested in
818 * the CPU for some time, we want to call BIOS
819 * power management - we probably want
822 #define IDLE_CALC_LIMIT (HZ * 100)
823 #define IDLE_LEAKY_MAX 16
825 static void (*original_pm_idle)(void) __read_mostly;
828 * apm_cpu_idle - cpu idling for APM capable Linux
830 * This is the idling function the kernel executes when APM is available. It
831 * tries to do BIOS powermanagement based on the average system idle time.
832 * Furthermore it calls the system default idle routine.
835 static void apm_cpu_idle(void)
837 static int use_apm_idle; /* = 0 */
838 static unsigned int last_jiffies; /* = 0 */
839 static unsigned int last_stime; /* = 0 */
841 int apm_idle_done = 0;
842 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
846 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
848 last_jiffies = jiffies;
849 last_stime = current->stime;
850 } else if (jiffies_since_last_check > idle_period) {
851 unsigned int idle_percentage;
853 idle_percentage = current->stime - last_stime;
854 idle_percentage *= 100;
855 idle_percentage /= jiffies_since_last_check;
856 use_apm_idle = (idle_percentage > idle_threshold);
857 if (apm_info.forbid_idle)
859 last_jiffies = jiffies;
860 last_stime = current->stime;
863 bucket = IDLE_LEAKY_MAX;
865 while (!need_resched()) {
870 switch (apm_do_idle()) {
871 case 0: apm_idle_done = 1;
874 bucket = IDLE_LEAKY_MAX;
882 case 1: apm_idle_done = 1;
884 default: /* BIOS refused */
888 if (original_pm_idle)
892 jiffies_since_last_check = jiffies - last_jiffies;
893 if (jiffies_since_last_check > idle_period)
902 * apm_power_off - ask the BIOS to power off
904 * Handle the power off sequence. This is the one piece of code we
905 * will execute even on SMP machines. In order to deal with BIOS
906 * bugs we support real mode APM BIOS power off calls. We also make
907 * the SMP call on CPU0 as some systems will only honour this call
908 * on their first cpu.
911 static void apm_power_off(void)
913 unsigned char po_bios_call[] = {
914 0xb8, 0x00, 0x10, /* movw $0x1000,ax */
915 0x8e, 0xd0, /* movw ax,ss */
916 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */
917 0xb8, 0x07, 0x53, /* movw $0x5307,ax */
918 0xbb, 0x01, 0x00, /* movw $0x0001,bx */
919 0xb9, 0x03, 0x00, /* movw $0x0003,cx */
920 0xcd, 0x15 /* int $0x15 */
923 /* Some bioses don't like being called from CPU != 0 */
924 if (apm_info.realmode_power_off)
926 (void)apm_save_cpus();
927 machine_real_restart(po_bios_call, sizeof(po_bios_call));
930 (void) set_system_power_state(APM_STATE_OFF);
933 #ifdef CONFIG_APM_DO_ENABLE
936 * apm_enable_power_management - enable BIOS APM power management
937 * @enable: enable yes/no
939 * Enable or disable the APM BIOS power services.
942 static int apm_enable_power_management(int enable)
946 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
947 return APM_NOT_ENGAGED;
948 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
950 return (eax >> 8) & 0xff;
952 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
954 apm_info.bios.flags |= APM_BIOS_DISABLED;
960 * apm_get_power_status - get current power state
961 * @status: returned status
963 * @life: estimated life
965 * Obtain the current power status from the APM BIOS. We return a
966 * status which gives the rough battery status, and current power
967 * source. The bat value returned give an estimate as a percentage
968 * of life and a status value for the battery. The estimated life
969 * if reported is a lifetime in secodnds/minutes at current powwer
973 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
981 if (apm_info.get_power_status_broken)
982 return APM_32_UNSUPPORTED;
983 if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
984 &eax, &ebx, &ecx, &edx, &dummy))
985 return (eax >> 8) & 0xff;
988 if (apm_info.get_power_status_swabinminutes) {
989 *life = swab16((u16)edx);
997 static int apm_get_battery_status(u_short which, u_short *status,
998 u_short *bat, u_short *life, u_short *nbat)
1006 if (apm_info.connection_version < 0x0102) {
1007 /* pretend we only have one battery. */
1009 return APM_BAD_DEVICE;
1011 return apm_get_power_status(status, bat, life);
1014 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1015 &ebx, &ecx, &edx, &esi))
1016 return (eax >> 8) & 0xff;
1026 * apm_engage_power_management - enable PM on a device
1027 * @device: identity of device
1030 * Activate or deactive power management on either a specific device
1031 * or the entire system (%APM_DEVICE_ALL).
1034 static int apm_engage_power_management(u_short device, int enable)
1038 if ((enable == 0) && (device == APM_DEVICE_ALL)
1039 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1040 return APM_DISABLED;
1041 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1042 return (eax >> 8) & 0xff;
1043 if (device == APM_DEVICE_ALL) {
1045 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1047 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1052 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1055 * apm_console_blank - blank the display
1058 * Attempt to blank the console, firstly by blanking just video device
1059 * zero, and if that fails (some BIOSes don't support it) then it blanks
1060 * all video devices. Typically the BIOS will do laptop backlight and
1061 * monitor powerdown for us.
1064 static int apm_console_blank(int blank)
1066 int error = APM_NOT_ENGAGED; /* silence gcc */
1069 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1071 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1073 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1074 error = set_power_state(dev[i], state);
1076 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1079 if (error == APM_NOT_ENGAGED)
1083 if (error == APM_NOT_ENGAGED) {
1087 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1089 apm_error("set display", error);
1090 apm_error("engage interface", eng_error);
1093 return apm_console_blank(blank);
1096 apm_error("set display", error);
1101 static int queue_empty(struct apm_user *as)
1103 return as->event_head == as->event_tail;
1106 static apm_event_t get_queued_event(struct apm_user *as)
1108 if (++as->event_tail >= APM_MAX_EVENTS)
1110 return as->events[as->event_tail];
1113 static void queue_event(apm_event_t event, struct apm_user *sender)
1115 struct apm_user * as;
1117 spin_lock(&user_list_lock);
1118 if (user_list == NULL)
1120 for (as = user_list; as != NULL; as = as->next) {
1121 if ((as == sender) || (!as->reader))
1123 if (++as->event_head >= APM_MAX_EVENTS)
1126 if (as->event_head == as->event_tail) {
1127 static int notified;
1129 if (notified++ == 0)
1130 printk(KERN_ERR "apm: an event queue overflowed\n");
1131 if (++as->event_tail >= APM_MAX_EVENTS)
1134 as->events[as->event_head] = event;
1135 if ((!as->suser) || (!as->writer))
1138 case APM_SYS_SUSPEND:
1139 case APM_USER_SUSPEND:
1140 as->suspends_pending++;
1144 case APM_SYS_STANDBY:
1145 case APM_USER_STANDBY:
1146 as->standbys_pending++;
1151 wake_up_interruptible(&apm_waitqueue);
1153 spin_unlock(&user_list_lock);
1156 static void set_time(void)
1159 if (got_clock_diff) { /* Must know time zone in order to set clock */
1160 ts.tv_sec = get_cmos_time() + clock_cmos_diff;
1162 do_settimeofday(&ts);
1166 static void get_time_diff(void)
1168 #ifndef CONFIG_APM_RTC_IS_GMT
1170 * Estimate time zone so that set_time can update the clock
1172 clock_cmos_diff = -get_cmos_time();
1173 clock_cmos_diff += get_seconds();
1178 static void reinit_timer(void)
1180 #ifdef INIT_TIMER_AFTER_SUSPEND
1181 unsigned long flags;
1183 spin_lock_irqsave(&i8253_lock, flags);
1184 /* set the clock to 100 Hz */
1185 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1187 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1189 outb(LATCH >> 8, PIT_CH0); /* MSB */
1191 spin_unlock_irqrestore(&i8253_lock, flags);
1195 static int suspend(int vetoable)
1198 struct apm_user *as;
1200 if (pm_send_all(PM_SUSPEND, (void *)3)) {
1203 if (apm_info.connection_version > 0x100)
1204 set_system_power_state(APM_STATE_REJECT);
1206 ignore_sys_suspend = 0;
1207 printk(KERN_WARNING "apm: suspend was vetoed.\n");
1210 printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
1213 device_suspend(PMSG_SUSPEND);
1214 local_irq_disable();
1215 device_power_down(PMSG_SUSPEND);
1217 /* serialize with the timer interrupt */
1218 write_seqlock(&xtime_lock);
1220 /* protect against access to timer chip registers */
1221 spin_lock(&i8253_lock);
1225 * Irq spinlock must be dropped around set_system_power_state.
1226 * We'll undo any timer changes due to interrupts below.
1228 spin_unlock(&i8253_lock);
1229 write_sequnlock(&xtime_lock);
1232 save_processor_state();
1233 err = set_system_power_state(APM_STATE_SUSPEND);
1234 ignore_normal_resume = 1;
1235 restore_processor_state();
1237 local_irq_disable();
1241 if (err == APM_NO_ERROR)
1243 if (err != APM_SUCCESS)
1244 apm_error("suspend", err);
1245 err = (err == APM_SUCCESS) ? 0 : -EIO;
1249 pm_send_all(PM_RESUME, (void *)0);
1250 queue_event(APM_NORMAL_RESUME, NULL);
1252 spin_lock(&user_list_lock);
1253 for (as = user_list; as != NULL; as = as->next) {
1254 as->suspend_wait = 0;
1255 as->suspend_result = err;
1257 spin_unlock(&user_list_lock);
1258 wake_up_interruptible(&apm_suspend_waitqueue);
1262 static void standby(void)
1266 local_irq_disable();
1267 device_power_down(PMSG_SUSPEND);
1268 /* serialize with the timer interrupt */
1269 write_seqlock(&xtime_lock);
1270 /* If needed, notify drivers here */
1272 write_sequnlock(&xtime_lock);
1275 err = set_system_power_state(APM_STATE_STANDBY);
1276 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1277 apm_error("standby", err);
1279 local_irq_disable();
1284 static apm_event_t get_event(void)
1287 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1288 apm_eventinfo_t info;
1290 static int notified;
1292 /* we don't use the eventinfo */
1293 error = apm_get_event(&event, &info);
1294 if (error == APM_SUCCESS)
1297 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1298 apm_error("get_event", error);
1303 static void check_events(void)
1306 static unsigned long last_resume;
1307 static int ignore_bounce;
1309 while ((event = get_event()) != 0) {
1311 if (event <= NR_APM_EVENT_NAME)
1312 printk(KERN_DEBUG "apm: received %s notify\n",
1313 apm_event_name[event - 1]);
1315 printk(KERN_DEBUG "apm: received unknown "
1316 "event 0x%02x\n", event);
1319 && ((jiffies - last_resume) > bounce_interval))
1323 case APM_SYS_STANDBY:
1324 case APM_USER_STANDBY:
1325 queue_event(event, NULL);
1326 if (standbys_pending <= 0)
1330 case APM_USER_SUSPEND:
1331 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1332 if (apm_info.connection_version > 0x100)
1333 set_system_power_state(APM_STATE_REJECT);
1336 case APM_SYS_SUSPEND:
1337 if (ignore_bounce) {
1338 if (apm_info.connection_version > 0x100)
1339 set_system_power_state(APM_STATE_REJECT);
1343 * If we are already processing a SUSPEND,
1344 * then further SUSPEND events from the BIOS
1345 * will be ignored. We also return here to
1346 * cope with the fact that the Thinkpads keep
1347 * sending a SUSPEND event until something else
1350 if (ignore_sys_suspend)
1352 ignore_sys_suspend = 1;
1353 queue_event(event, NULL);
1354 if (suspends_pending <= 0)
1358 case APM_NORMAL_RESUME:
1359 case APM_CRITICAL_RESUME:
1360 case APM_STANDBY_RESUME:
1361 ignore_sys_suspend = 0;
1362 last_resume = jiffies;
1364 if ((event != APM_NORMAL_RESUME)
1365 || (ignore_normal_resume == 0)) {
1368 pm_send_all(PM_RESUME, (void *)0);
1369 queue_event(event, NULL);
1371 ignore_normal_resume = 0;
1374 case APM_CAPABILITY_CHANGE:
1375 case APM_LOW_BATTERY:
1376 case APM_POWER_STATUS_CHANGE:
1377 queue_event(event, NULL);
1378 /* If needed, notify drivers here */
1381 case APM_UPDATE_TIME:
1385 case APM_CRITICAL_SUSPEND:
1387 * We are not allowed to reject a critical suspend.
1395 static void apm_event_handler(void)
1397 static int pending_count = 4;
1400 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1401 if ((apm_info.connection_version > 0x100) &&
1402 (pending_count-- <= 0)) {
1405 printk(KERN_DEBUG "apm: setting state busy\n");
1406 err = set_system_power_state(APM_STATE_BUSY);
1408 apm_error("busy", err);
1416 * This is the APM thread main loop.
1419 static void apm_mainloop(void)
1421 DECLARE_WAITQUEUE(wait, current);
1423 add_wait_queue(&apm_waitqueue, &wait);
1424 set_current_state(TASK_INTERRUPTIBLE);
1426 schedule_timeout(APM_CHECK_TIMEOUT);
1427 if (kthread_should_stop())
1430 * Ok, check all events, check for idle (and mark us sleeping
1431 * so as not to count towards the load average)..
1433 set_current_state(TASK_INTERRUPTIBLE);
1434 apm_event_handler();
1436 remove_wait_queue(&apm_waitqueue, &wait);
1439 static int check_apm_user(struct apm_user *as, const char *func)
1441 if ((as == NULL) || (as->magic != APM_BIOS_MAGIC)) {
1442 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1448 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1450 struct apm_user * as;
1454 as = fp->private_data;
1455 if (check_apm_user(as, "read"))
1457 if ((int)count < sizeof(apm_event_t))
1459 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1461 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1463 while ((i >= sizeof(event)) && !queue_empty(as)) {
1464 event = get_queued_event(as);
1465 if (copy_to_user(buf, &event, sizeof(event))) {
1471 case APM_SYS_SUSPEND:
1472 case APM_USER_SUSPEND:
1473 as->suspends_read++;
1476 case APM_SYS_STANDBY:
1477 case APM_USER_STANDBY:
1478 as->standbys_read++;
1481 buf += sizeof(event);
1486 if (signal_pending(current))
1487 return -ERESTARTSYS;
1491 static unsigned int do_poll(struct file *fp, poll_table * wait)
1493 struct apm_user * as;
1495 as = fp->private_data;
1496 if (check_apm_user(as, "poll"))
1498 poll_wait(fp, &apm_waitqueue, wait);
1499 if (!queue_empty(as))
1500 return POLLIN | POLLRDNORM;
1504 static int do_ioctl(struct inode * inode, struct file *filp,
1505 u_int cmd, u_long arg)
1507 struct apm_user * as;
1509 as = filp->private_data;
1510 if (check_apm_user(as, "ioctl"))
1512 if ((!as->suser) || (!as->writer))
1515 case APM_IOC_STANDBY:
1516 if (as->standbys_read > 0) {
1517 as->standbys_read--;
1518 as->standbys_pending--;
1521 queue_event(APM_USER_STANDBY, as);
1522 if (standbys_pending <= 0)
1525 case APM_IOC_SUSPEND:
1526 if (as->suspends_read > 0) {
1527 as->suspends_read--;
1528 as->suspends_pending--;
1531 queue_event(APM_USER_SUSPEND, as);
1532 if (suspends_pending <= 0) {
1535 as->suspend_wait = 1;
1536 wait_event_interruptible(apm_suspend_waitqueue,
1537 as->suspend_wait == 0);
1538 return as->suspend_result;
1547 static int do_release(struct inode * inode, struct file * filp)
1549 struct apm_user * as;
1551 as = filp->private_data;
1552 if (check_apm_user(as, "release"))
1554 filp->private_data = NULL;
1555 if (as->standbys_pending > 0) {
1556 standbys_pending -= as->standbys_pending;
1557 if (standbys_pending <= 0)
1560 if (as->suspends_pending > 0) {
1561 suspends_pending -= as->suspends_pending;
1562 if (suspends_pending <= 0)
1565 spin_lock(&user_list_lock);
1566 if (user_list == as)
1567 user_list = as->next;
1569 struct apm_user * as1;
1571 for (as1 = user_list;
1572 (as1 != NULL) && (as1->next != as);
1576 printk(KERN_ERR "apm: filp not in user list\n");
1578 as1->next = as->next;
1580 spin_unlock(&user_list_lock);
1585 static int do_open(struct inode * inode, struct file * filp)
1587 struct apm_user * as;
1589 as = (struct apm_user *)kmalloc(sizeof(*as), GFP_KERNEL);
1591 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1595 as->magic = APM_BIOS_MAGIC;
1596 as->event_tail = as->event_head = 0;
1597 as->suspends_pending = as->standbys_pending = 0;
1598 as->suspends_read = as->standbys_read = 0;
1600 * XXX - this is a tiny bit broken, when we consider BSD
1601 * process accounting. If the device is opened by root, we
1602 * instantly flag that we used superuser privs. Who knows,
1603 * we might close the device immediately without doing a
1604 * privileged operation -- cevans
1606 as->suser = capable(CAP_SYS_ADMIN);
1607 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1608 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1609 spin_lock(&user_list_lock);
1610 as->next = user_list;
1612 spin_unlock(&user_list_lock);
1613 filp->private_data = as;
1617 static int apm_get_info(char *buf, char **start, off_t fpos, int length)
1624 unsigned short ac_line_status = 0xff;
1625 unsigned short battery_status = 0xff;
1626 unsigned short battery_flag = 0xff;
1627 int percentage = -1;
1628 int time_units = -1;
1633 if ((num_online_cpus() == 1) &&
1634 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1635 ac_line_status = (bx >> 8) & 0xff;
1636 battery_status = bx & 0xff;
1637 if ((cx & 0xff) != 0xff)
1638 percentage = cx & 0xff;
1640 if (apm_info.connection_version > 0x100) {
1641 battery_flag = (cx >> 8) & 0xff;
1643 units = (dx & 0x8000) ? "min" : "sec";
1644 time_units = dx & 0x7fff;
1648 /* Arguments, with symbols from linux/apm_bios.h. Information is
1649 from the Get Power Status (0x0a) call unless otherwise noted.
1651 0) Linux driver version (this will change if format changes)
1652 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1653 2) APM flags from APM Installation Check (0x00):
1654 bit 0: APM_16_BIT_SUPPORT
1655 bit 1: APM_32_BIT_SUPPORT
1656 bit 2: APM_IDLE_SLOWS_CLOCK
1657 bit 3: APM_BIOS_DISABLED
1658 bit 4: APM_BIOS_DISENGAGED
1662 0x02: On backup power (BIOS >= 1.1 only)
1669 0x04: Selected battery not present (BIOS >= 1.2 only)
1676 bit 7: No system battery
1678 6) Remaining battery life (percentage of charge):
1681 7) Remaining battery life (time units):
1682 Number of remaining minutes or seconds
1684 8) min = minutes; sec = seconds */
1686 p += sprintf(p, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1688 (apm_info.bios.version >> 8) & 0xff,
1689 apm_info.bios.version & 0xff,
1690 apm_info.bios.flags,
1701 static int apm(void *unused)
1712 * This is to avoid random crashes at boot time during initialization
1713 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1714 * Some bioses don't like being called from CPU != 0.
1715 * Method suggested by Ingo Molnar.
1717 set_cpus_allowed(current, cpumask_of_cpu(0));
1718 BUG_ON(smp_processor_id() != 0);
1721 if (apm_info.connection_version == 0) {
1722 apm_info.connection_version = apm_info.bios.version;
1723 if (apm_info.connection_version > 0x100) {
1725 * We only support BIOSs up to version 1.2
1727 if (apm_info.connection_version > 0x0102)
1728 apm_info.connection_version = 0x0102;
1729 error = apm_driver_version(&apm_info.connection_version);
1730 if (error != APM_SUCCESS) {
1731 apm_error("driver version", error);
1732 /* Fall back to an APM 1.0 connection. */
1733 apm_info.connection_version = 0x100;
1739 printk(KERN_INFO "apm: Connection version %d.%d\n",
1740 (apm_info.connection_version >> 8) & 0xff,
1741 apm_info.connection_version & 0xff);
1743 #ifdef CONFIG_APM_DO_ENABLE
1744 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1746 * This call causes my NEC UltraLite Versa 33/C to hang if it
1747 * is booted with PM disabled but not in the docking station.
1750 error = apm_enable_power_management(1);
1752 apm_error("enable power management", error);
1758 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1759 && (apm_info.connection_version > 0x0100)) {
1760 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1762 apm_error("engage power management", error);
1767 if (debug && (num_online_cpus() == 1 || smp )) {
1768 error = apm_get_power_status(&bx, &cx, &dx);
1770 printk(KERN_INFO "apm: power status not available\n");
1772 switch ((bx >> 8) & 0xff) {
1773 case 0: power_stat = "off line"; break;
1774 case 1: power_stat = "on line"; break;
1775 case 2: power_stat = "on backup power"; break;
1776 default: power_stat = "unknown"; break;
1778 switch (bx & 0xff) {
1779 case 0: bat_stat = "high"; break;
1780 case 1: bat_stat = "low"; break;
1781 case 2: bat_stat = "critical"; break;
1782 case 3: bat_stat = "charging"; break;
1783 default: bat_stat = "unknown"; break;
1786 "apm: AC %s, battery status %s, battery life ",
1787 power_stat, bat_stat);
1788 if ((cx & 0xff) == 0xff)
1789 printk("unknown\n");
1791 printk("%d%%\n", cx & 0xff);
1792 if (apm_info.connection_version > 0x100) {
1794 "apm: battery flag 0x%02x, battery life ",
1797 printk("unknown\n");
1799 printk("%d %s\n", dx & 0x7fff,
1801 "minutes" : "seconds");
1806 /* Install our power off handler.. */
1808 pm_power_off = apm_power_off;
1810 if (num_online_cpus() == 1 || smp) {
1811 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1812 console_blank_hook = apm_console_blank;
1815 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1816 console_blank_hook = NULL;
1824 static int __init apm_setup(char *str)
1828 while ((str != NULL) && (*str != '\0')) {
1829 if (strncmp(str, "off", 3) == 0)
1831 if (strncmp(str, "on", 2) == 0)
1833 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1834 (strncmp(str, "bounce_interval=", 16) == 0))
1835 bounce_interval = simple_strtol(str + 16, NULL, 0);
1836 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1837 (strncmp(str, "idle_threshold=", 15) == 0))
1838 idle_threshold = simple_strtol(str + 15, NULL, 0);
1839 if ((strncmp(str, "idle-period=", 12) == 0) ||
1840 (strncmp(str, "idle_period=", 12) == 0))
1841 idle_period = simple_strtol(str + 12, NULL, 0);
1842 invert = (strncmp(str, "no-", 3) == 0) ||
1843 (strncmp(str, "no_", 3) == 0);
1846 if (strncmp(str, "debug", 5) == 0)
1848 if ((strncmp(str, "power-off", 9) == 0) ||
1849 (strncmp(str, "power_off", 9) == 0))
1850 power_off = !invert;
1851 if (strncmp(str, "smp", 3) == 0)
1854 idle_threshold = 100;
1856 if ((strncmp(str, "allow-ints", 10) == 0) ||
1857 (strncmp(str, "allow_ints", 10) == 0))
1858 apm_info.allow_ints = !invert;
1859 if ((strncmp(str, "broken-psr", 10) == 0) ||
1860 (strncmp(str, "broken_psr", 10) == 0))
1861 apm_info.get_power_status_broken = !invert;
1862 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1863 (strncmp(str, "realmode_power_off", 18) == 0))
1864 apm_info.realmode_power_off = !invert;
1865 str = strchr(str, ',');
1867 str += strspn(str, ", \t");
1872 __setup("apm=", apm_setup);
1875 static struct file_operations apm_bios_fops = {
1876 .owner = THIS_MODULE,
1881 .release = do_release,
1884 static struct miscdevice apm_device = {
1891 /* Simple "print if true" callback */
1892 static int __init print_if_true(struct dmi_system_id *d)
1894 printk("%s\n", d->ident);
1899 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1900 * disabled before the suspend. Linux used to get terribly confused by that.
1902 static int __init broken_ps2_resume(struct dmi_system_id *d)
1904 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug workaround hopefully not needed.\n", d->ident);
1908 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1909 static int __init set_realmode_power_off(struct dmi_system_id *d)
1911 if (apm_info.realmode_power_off == 0) {
1912 apm_info.realmode_power_off = 1;
1913 printk(KERN_INFO "%s bios detected. Using realmode poweroff only.\n", d->ident);
1918 /* Some laptops require interrupts to be enabled during APM calls */
1919 static int __init set_apm_ints(struct dmi_system_id *d)
1921 if (apm_info.allow_ints == 0) {
1922 apm_info.allow_ints = 1;
1923 printk(KERN_INFO "%s machine detected. Enabling interrupts during APM calls.\n", d->ident);
1928 /* Some APM bioses corrupt memory or just plain do not work */
1929 static int __init apm_is_horked(struct dmi_system_id *d)
1931 if (apm_info.disabled == 0) {
1932 apm_info.disabled = 1;
1933 printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
1938 static int __init apm_is_horked_d850md(struct dmi_system_id *d)
1940 if (apm_info.disabled == 0) {
1941 apm_info.disabled = 1;
1942 printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
1943 printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
1944 printk(KERN_INFO "download from support.intel.com \n");
1949 /* Some APM bioses hang on APM idle calls */
1950 static int __init apm_likes_to_melt(struct dmi_system_id *d)
1952 if (apm_info.forbid_idle == 0) {
1953 apm_info.forbid_idle = 1;
1954 printk(KERN_INFO "%s machine detected. Disabling APM idle calls.\n", d->ident);
1960 * Check for clue free BIOS implementations who use
1961 * the following QA technique
1963 * [ Write BIOS Code ]<------
1965 * < Does it Compile >----N--
1967 * < Does it Boot Win98 >-N--
1971 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
1972 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
1974 static int __init broken_apm_power(struct dmi_system_id *d)
1976 apm_info.get_power_status_broken = 1;
1977 printk(KERN_WARNING "BIOS strings suggest APM bugs, disabling power status reporting.\n");
1982 * This bios swaps the APM minute reporting bytes over (Many sony laptops
1983 * have this problem).
1985 static int __init swab_apm_power_in_minutes(struct dmi_system_id *d)
1987 apm_info.get_power_status_swabinminutes = 1;
1988 printk(KERN_WARNING "BIOS strings suggest APM reports battery life in minutes and wrong byte order.\n");
1992 static struct dmi_system_id __initdata apm_dmi_table[] = {
1995 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
1996 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
1997 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
1999 { /* Handle problems with APM on the C600 */
2000 broken_ps2_resume, "Dell Latitude C600",
2001 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2002 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2004 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2005 set_apm_ints, "Dell Latitude",
2006 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2007 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2010 apm_is_horked, "Dell Inspiron 2500",
2011 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2012 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2013 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
2014 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2016 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2017 set_apm_ints, "Dell Inspiron", {
2018 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2019 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2021 { /* Handle problems with APM on Inspiron 5000e */
2022 broken_apm_power, "Dell Inspiron 5000e",
2023 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2024 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2025 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2027 { /* Handle problems with APM on Inspiron 2500 */
2028 broken_apm_power, "Dell Inspiron 2500",
2029 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2030 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2031 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2034 apm_is_horked, "Dell Dimension 4100",
2035 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2036 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2037 DMI_MATCH(DMI_BIOS_VENDOR,"Intel Corp."),
2038 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2040 { /* Allow interrupts during suspend on Compaq Laptops*/
2041 set_apm_ints, "Compaq 12XL125",
2042 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2043 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2044 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2045 DMI_MATCH(DMI_BIOS_VERSION,"4.06"), },
2047 { /* Allow interrupts during APM or the clock goes slow */
2048 set_apm_ints, "ASUSTeK",
2049 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2050 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2052 { /* APM blows on shutdown */
2053 apm_is_horked, "ABIT KX7-333[R]",
2054 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2055 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2058 apm_is_horked, "Trigem Delhi3",
2059 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2060 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2063 apm_is_horked, "Fujitsu-Siemens",
2064 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2065 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2068 apm_is_horked_d850md, "Intel D850MD",
2069 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2070 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2073 apm_is_horked, "Intel D810EMO",
2074 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2075 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2078 apm_is_horked, "Dell XPS-Z",
2079 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2080 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2081 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2084 apm_is_horked, "Sharp PC-PJ/AX",
2085 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2086 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2087 DMI_MATCH(DMI_BIOS_VENDOR,"SystemSoft"),
2088 DMI_MATCH(DMI_BIOS_VERSION,"Version R2.08"), },
2091 apm_is_horked, "Dell Inspiron 2500",
2092 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2093 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2094 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
2095 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2097 { /* APM idle hangs */
2098 apm_likes_to_melt, "Jabil AMD",
2099 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2100 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2102 { /* APM idle hangs */
2103 apm_likes_to_melt, "AMI Bios",
2104 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2105 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2107 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2108 swab_apm_power_in_minutes, "Sony VAIO",
2109 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2110 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2111 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2113 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2114 swab_apm_power_in_minutes, "Sony VAIO",
2115 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2116 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2117 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2119 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2120 swab_apm_power_in_minutes, "Sony VAIO",
2121 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2122 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2123 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2125 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2126 swab_apm_power_in_minutes, "Sony VAIO",
2127 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2128 DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2129 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2131 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2132 swab_apm_power_in_minutes, "Sony VAIO",
2133 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2134 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2135 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2137 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2138 swab_apm_power_in_minutes, "Sony VAIO",
2139 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2140 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2141 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2143 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2144 swab_apm_power_in_minutes, "Sony VAIO",
2145 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2146 DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2147 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2149 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2150 swab_apm_power_in_minutes, "Sony VAIO",
2151 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2152 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2153 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2155 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2156 swab_apm_power_in_minutes, "Sony VAIO",
2157 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2158 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2159 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2161 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2162 swab_apm_power_in_minutes, "Sony VAIO",
2163 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2164 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2165 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2168 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2169 swab_apm_power_in_minutes, "Sony VAIO",
2170 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2171 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2172 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2174 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2175 swab_apm_power_in_minutes, "Sony VAIO",
2176 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2177 DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2178 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2180 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2181 swab_apm_power_in_minutes, "Sony VAIO",
2182 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2183 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2184 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2186 { /* broken PM poweroff bios */
2187 set_realmode_power_off, "Award Software v4.60 PGMA",
2188 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2189 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2190 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2193 /* Generic per vendor APM settings */
2195 { /* Allow interrupts during suspend on IBM laptops */
2196 set_apm_ints, "IBM",
2197 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2204 * Just start the APM thread. We do NOT want to do APM BIOS
2205 * calls from anything but the APM thread, if for no other reason
2206 * than the fact that we don't trust the APM BIOS. This way,
2207 * most common APM BIOS problems that lead to protection errors
2208 * etc will have at least some level of being contained...
2210 * In short, if something bad happens, at least we have a choice
2211 * of just killing the apm thread..
2213 static int __init apm_init(void)
2215 struct proc_dir_entry *apm_proc;
2216 struct desc_struct *gdt;
2219 dmi_check_system(apm_dmi_table);
2221 if (apm_info.bios.version == 0) {
2222 printk(KERN_INFO "apm: BIOS not found.\n");
2226 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2227 ((apm_info.bios.version >> 8) & 0xff),
2228 (apm_info.bios.version & 0xff),
2229 apm_info.bios.flags,
2231 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2232 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2237 apm_info.allow_ints = 1;
2239 apm_info.get_power_status_broken = 1;
2240 if (realmode_power_off)
2241 apm_info.realmode_power_off = 1;
2242 /* User can override, but default is to trust DMI */
2243 if (apm_disabled != -1)
2244 apm_info.disabled = apm_disabled;
2247 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2248 * but is reportedly a 1.0 BIOS.
2250 if (apm_info.bios.version == 0x001)
2251 apm_info.bios.version = 0x100;
2253 /* BIOS < 1.2 doesn't set cseg_16_len */
2254 if (apm_info.bios.version < 0x102)
2255 apm_info.bios.cseg_16_len = 0; /* 64k */
2258 printk(KERN_INFO "apm: entry %x:%lx cseg16 %x dseg %x",
2259 apm_info.bios.cseg, apm_info.bios.offset,
2260 apm_info.bios.cseg_16, apm_info.bios.dseg);
2261 if (apm_info.bios.version > 0x100)
2262 printk(" cseg len %x, dseg len %x",
2263 apm_info.bios.cseg_len,
2264 apm_info.bios.dseg_len);
2265 if (apm_info.bios.version > 0x101)
2266 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2270 if (apm_info.disabled) {
2271 printk(KERN_NOTICE "apm: disabled on user request.\n");
2274 if ((num_online_cpus() > 1) && !power_off && !smp) {
2275 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2276 apm_info.disabled = 1;
2279 if (PM_IS_ACTIVE()) {
2280 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2281 apm_info.disabled = 1;
2284 #ifdef CONFIG_PM_LEGACY
2289 * Set up a segment that references the real mode segment 0x40
2290 * that extends up to the end of page zero (that we have reserved).
2291 * This is for buggy BIOS's that refer to (real mode) segment 0x40
2292 * even though they are called in protected mode.
2294 set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2295 _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2298 * Set up the long jump entry point to the APM BIOS, which is called
2299 * from inline assembly.
2301 apm_bios_entry.offset = apm_info.bios.offset;
2302 apm_bios_entry.segment = APM_CS;
2305 * The APM 1.1 BIOS is supposed to provide limit information that it
2306 * recognizes. Many machines do this correctly, but many others do
2307 * not restrict themselves to their claimed limit. When this happens,
2308 * they will cause a segmentation violation in the kernel at boot time.
2309 * Most BIOS's, however, will respect a 64k limit, so we use that.
2311 * Note we only set APM segments on CPU zero, since we pin the APM
2314 gdt = get_cpu_gdt_table(0);
2315 set_base(gdt[APM_CS >> 3],
2316 __va((unsigned long)apm_info.bios.cseg << 4));
2317 set_base(gdt[APM_CS_16 >> 3],
2318 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2319 set_base(gdt[APM_DS >> 3],
2320 __va((unsigned long)apm_info.bios.dseg << 4));
2322 apm_proc = create_proc_info_entry("apm", 0, NULL, apm_get_info);
2324 apm_proc->owner = THIS_MODULE;
2326 kapmd_task = kthread_create(apm, NULL, "kapmd");
2327 if (IS_ERR(kapmd_task)) {
2328 printk(KERN_ERR "apm: disabled - Unable to start kernel "
2330 err = PTR_ERR(kapmd_task);
2332 remove_proc_entry("apm", NULL);
2335 kapmd_task->flags |= PF_NOFREEZE;
2336 wake_up_process(kapmd_task);
2338 if (num_online_cpus() > 1 && !smp ) {
2340 "apm: disabled - APM is not SMP safe (power off active).\n");
2345 * Note we don't actually care if the misc_device cannot be registered.
2346 * this driver can do its job without it, even if userspace can't
2347 * control it. just log the error
2349 if (misc_register(&apm_device))
2350 printk(KERN_WARNING "apm: Could not register misc device.\n");
2353 idle_period = (idle_period * HZ) / 100;
2354 if (idle_threshold < 100) {
2355 original_pm_idle = pm_idle;
2356 pm_idle = apm_cpu_idle;
2363 static void __exit apm_exit(void)
2368 pm_idle = original_pm_idle;
2370 * We are about to unload the current idle thread pm callback
2371 * (pm_idle), Wait for all processors to update cached/local
2372 * copies of pm_idle before proceeding.
2376 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2377 && (apm_info.connection_version > 0x0100)) {
2378 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2380 apm_error("disengage power management", error);
2382 misc_deregister(&apm_device);
2383 remove_proc_entry("apm", NULL);
2385 pm_power_off = NULL;
2387 kthread_stop(kapmd_task);
2390 #ifdef CONFIG_PM_LEGACY
2395 module_init(apm_init);
2396 module_exit(apm_exit);
2398 MODULE_AUTHOR("Stephen Rothwell");
2399 MODULE_DESCRIPTION("Advanced Power Management");
2400 MODULE_LICENSE("GPL");
2401 module_param(debug, bool, 0644);
2402 MODULE_PARM_DESC(debug, "Enable debug mode");
2403 module_param(power_off, bool, 0444);
2404 MODULE_PARM_DESC(power_off, "Enable power off");
2405 module_param(bounce_interval, int, 0444);
2406 MODULE_PARM_DESC(bounce_interval,
2407 "Set the number of ticks to ignore suspend bounces");
2408 module_param(allow_ints, bool, 0444);
2409 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2410 module_param(broken_psr, bool, 0444);
2411 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2412 module_param(realmode_power_off, bool, 0444);
2413 MODULE_PARM_DESC(realmode_power_off,
2414 "Switch to real mode before powering off");
2415 module_param(idle_threshold, int, 0444);
2416 MODULE_PARM_DESC(idle_threshold,
2417 "System idle percentage above which to make APM BIOS idle calls");
2418 module_param(idle_period, int, 0444);
2419 MODULE_PARM_DESC(idle_period,
2420 "Period (in sec/100) over which to caculate the idle percentage");
2421 module_param(smp, bool, 0444);
2422 MODULE_PARM_DESC(smp,
2423 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2424 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);