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 replacement for it is, but Linux doesn't yet support this.
61 * Alan Cox Linux 2.1.55
62 * 1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
63 * 1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
64 * Dean Gaudet <dgaudet@arctic.org>.
65 * C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
66 * 1.5: Fix segment register reloading (in case of bad segments saved
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@ucw.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@lxorguk.ukuu.org.uk>).
164 * 1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165 * calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
166 * If an APM idle fails log it and idle sensibly
167 * 1.15: Don't queue events to clients who open the device O_WRONLY.
168 * Don't expect replies from clients who open the device O_RDONLY.
169 * (Idea from Thomas Hood)
170 * Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
171 * 1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
172 * Notify listeners of standby or suspend events before notifying
173 * drivers. Return EBUSY to ioctl() if suspend is rejected.
174 * (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
175 * Ignore first resume after we generate our own resume event
176 * after a suspend (Thomas Hood)
177 * Daemonize now gets rid of our controlling terminal (sfr).
178 * CONFIG_APM_CPU_IDLE now just affects the default value of
179 * idle_threshold (sfr).
180 * Change name of kernel apm daemon (as it no longer idles) (sfr).
181 * 1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
182 * make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
183 * TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
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 from
193 * http://www.microsoft.com/whdc/archive/amp_12.mspx 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/whdc/archive/amp_12.mspx]
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/seq_file.h>
215 #include <linux/miscdevice.h>
216 #include <linux/apm_bios.h>
217 #include <linux/init.h>
218 #include <linux/time.h>
219 #include <linux/sched.h>
220 #include <linux/pm.h>
221 #include <linux/capability.h>
222 #include <linux/device.h>
223 #include <linux/kernel.h>
224 #include <linux/freezer.h>
225 #include <linux/smp.h>
226 #include <linux/dmi.h>
227 #include <linux/suspend.h>
228 #include <linux/kthread.h>
229 #include <linux/jiffies.h>
230 #include <linux/acpi.h>
232 #include <asm/system.h>
233 #include <asm/uaccess.h>
234 #include <asm/desc.h>
235 #include <asm/i8253.h>
236 #include <asm/olpc.h>
237 #include <asm/paravirt.h>
238 #include <asm/reboot.h>
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 static int debug __read_mostly;
387 static int smp __read_mostly;
388 static int apm_disabled = -1;
390 static int power_off;
392 static int power_off = 1;
394 static int realmode_power_off;
395 #ifdef CONFIG_APM_ALLOW_INTS
396 static int allow_ints = 1;
398 static int allow_ints;
400 static int broken_psr;
402 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
403 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
404 static struct apm_user *user_list;
405 static DEFINE_SPINLOCK(user_list_lock);
406 static DEFINE_MUTEX(apm_mutex);
409 * Set up a segment that references the real mode segment 0x40
410 * that extends up to the end of page zero (that we have reserved).
411 * This is for buggy BIOS's that refer to (real mode) segment 0x40
412 * even though they are called in protected mode.
414 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
415 (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
417 static const char driver_version[] = "1.16ac"; /* no spaces */
419 static struct task_struct *kapmd_task;
422 * APM event names taken from the APM 1.2 specification. These are
423 * the message codes that the BIOS uses to tell us about events
425 static const char * const apm_event_name[] = {
431 "power status change",
436 "system standby resume",
437 "capabilities change"
439 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
441 typedef struct lookup_t {
447 * The BIOS returns a set of standard error codes in AX when the
451 static const lookup_t error_table[] = {
452 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
453 { APM_DISABLED, "Power management disabled" },
454 { APM_CONNECTED, "Real mode interface already connected" },
455 { APM_NOT_CONNECTED, "Interface not connected" },
456 { APM_16_CONNECTED, "16 bit interface already connected" },
457 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
458 { APM_32_CONNECTED, "32 bit interface already connected" },
459 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
460 { APM_BAD_DEVICE, "Unrecognized device ID" },
461 { APM_BAD_PARAM, "Parameter out of range" },
462 { APM_NOT_ENGAGED, "Interface not engaged" },
463 { APM_BAD_FUNCTION, "Function not supported" },
464 { APM_RESUME_DISABLED, "Resume timer disabled" },
465 { APM_BAD_STATE, "Unable to enter requested state" },
466 /* N/A { APM_NO_EVENTS, "No events pending" }, */
467 { APM_NO_ERROR, "BIOS did not set a return code" },
468 { APM_NOT_PRESENT, "No APM present" }
470 #define ERROR_COUNT ARRAY_SIZE(error_table)
473 * apm_error - display an APM error
474 * @str: information string
475 * @err: APM BIOS return code
477 * Write a meaningful log entry to the kernel log in the event of
478 * an APM error. Note that this also handles (negative) kernel errors.
481 static void apm_error(char *str, int err)
485 for (i = 0; i < ERROR_COUNT; i++)
486 if (error_table[i].key == err)
489 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
491 printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err);
493 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
498 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
499 * apm_info.allow_ints, we are being really paranoid here! Not only
500 * are interrupts disabled, but all the segment registers (except SS)
501 * are saved and zeroed this means that if the BIOS tries to reference
502 * any data without explicitly loading the segment registers, the kernel
503 * will fault immediately rather than have some unforeseen circumstances
504 * for the rest of the kernel. And it will be very obvious! :-) Doing
505 * this depends on CS referring to the same physical memory as DS so that
506 * DS can be zeroed before the call. Unfortunately, we can't do anything
507 * about the stack segment/pointer. Also, we tell the compiler that
508 * everything could change.
510 * Also, we KNOW that for the non error case of apm_bios_call, there
511 * is no useful data returned in the low order 8 bits of eax.
514 static inline unsigned long __apm_irq_save(void)
517 local_save_flags(flags);
518 if (apm_info.allow_ints) {
519 if (irqs_disabled_flags(flags))
527 #define apm_irq_save(flags) \
528 do { flags = __apm_irq_save(); } while (0)
530 static inline void apm_irq_restore(unsigned long flags)
532 if (irqs_disabled_flags(flags))
534 else if (irqs_disabled())
539 # define APM_DECL_SEGS \
540 unsigned int saved_fs; unsigned int saved_gs;
541 # define APM_DO_SAVE_SEGS \
542 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
543 # define APM_DO_RESTORE_SEGS \
544 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
546 # define APM_DECL_SEGS
547 # define APM_DO_SAVE_SEGS
548 # define APM_DO_RESTORE_SEGS
551 struct apm_bios_call {
561 /* Error: -ENOMEM, or bits 8-15 of eax */
566 * __apm_bios_call - Make an APM BIOS 32bit call
567 * @_call: pointer to struct apm_bios_call.
569 * Make an APM call using the 32bit protected mode interface. The
570 * caller is responsible for knowing if APM BIOS is configured and
571 * enabled. This call can disable interrupts for a long period of
572 * time on some laptops. The return value is in AH and the carry
573 * flag is loaded into AL. If there is an error, then the error
574 * code is returned in AH (bits 8-15 of eax) and this function
577 * Note: this makes the call on the current CPU.
579 static long __apm_bios_call(void *_call)
584 struct desc_struct save_desc_40;
585 struct desc_struct *gdt;
586 struct apm_bios_call *call = _call;
590 gdt = get_cpu_gdt_table(cpu);
591 save_desc_40 = gdt[0x40 / 8];
592 gdt[0x40 / 8] = bad_bios_desc;
596 apm_bios_call_asm(call->func, call->ebx, call->ecx,
597 &call->eax, &call->ebx, &call->ecx, &call->edx,
600 apm_irq_restore(flags);
601 gdt[0x40 / 8] = save_desc_40;
604 return call->eax & 0xff;
607 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
608 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
612 /* Don't bother with work_on_cpu in the common case, so we don't
613 * have to worry about OOM or overhead. */
614 if (get_cpu() == 0) {
619 ret = work_on_cpu(0, fn, call);
622 /* work_on_cpu can fail with -ENOMEM */
626 call->err = (call->eax >> 8) & 0xff;
632 * apm_bios_call - Make an APM BIOS 32bit call (on CPU 0)
633 * @call: the apm_bios_call registers.
635 * If there is an error, it is returned in @call.err.
637 static int apm_bios_call(struct apm_bios_call *call)
639 return on_cpu0(__apm_bios_call, call);
643 * __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
644 * @_call: pointer to struct apm_bios_call.
646 * Make a BIOS call that returns one value only, or just status.
647 * If there is an error, then the error code is returned in AH
648 * (bits 8-15 of eax) and this function returns non-zero (it can
649 * also return -ENOMEM). This is used for simpler BIOS operations.
650 * This call may hold interrupts off for a long time on some laptops.
652 * Note: this makes the call on the current CPU.
654 static long __apm_bios_call_simple(void *_call)
660 struct desc_struct save_desc_40;
661 struct desc_struct *gdt;
662 struct apm_bios_call *call = _call;
666 gdt = get_cpu_gdt_table(cpu);
667 save_desc_40 = gdt[0x40 / 8];
668 gdt[0x40 / 8] = bad_bios_desc;
672 error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
675 apm_irq_restore(flags);
676 gdt[0x40 / 8] = save_desc_40;
682 * apm_bios_call_simple - make a simple APM BIOS 32bit call
683 * @func: APM function to invoke
684 * @ebx_in: EBX register value for BIOS call
685 * @ecx_in: ECX register value for BIOS call
686 * @eax: EAX register on return from the BIOS call
689 * Make a BIOS call that returns one value only, or just status.
690 * If there is an error, then the error code is returned in @err
691 * and this function returns non-zero. This is used for simpler
692 * BIOS operations. This call may hold interrupts off for a long
693 * time on some laptops.
695 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
698 struct apm_bios_call call;
705 ret = on_cpu0(__apm_bios_call_simple, &call);
712 * apm_driver_version - APM driver version
713 * @val: loaded with the APM version on return
715 * Retrieve the APM version supported by the BIOS. This is only
716 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
719 * On entry val should point to a value indicating the APM driver
720 * version with the high byte being the major and the low byte the
721 * minor number both in BCD
723 * On return it will hold the BIOS revision supported in the
727 static int apm_driver_version(u_short *val)
732 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
739 * apm_get_event - get an APM event from the BIOS
740 * @event: pointer to the event
741 * @info: point to the event information
743 * The APM BIOS provides a polled information for event
744 * reporting. The BIOS expects to be polled at least every second
745 * when events are pending. When a message is found the caller should
746 * poll until no more messages are present. However, this causes
747 * problems on some laptops where a suspend event notification is
748 * not cleared until it is acknowledged.
750 * Additional information is returned in the info pointer, providing
751 * that APM 1.2 is in use. If no messges are pending the value 0x80
752 * is returned (No power management events pending).
754 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
756 struct apm_bios_call call;
758 call.func = APM_FUNC_GET_EVENT;
759 call.ebx = call.ecx = 0;
761 if (apm_bios_call(&call))
765 if (apm_info.connection_version < 0x0102)
766 *info = ~0; /* indicate info not valid */
773 * set_power_state - set the power management state
774 * @what: which items to transition
775 * @state: state to transition to
777 * Request an APM change of state for one or more system devices. The
778 * processor state must be transitioned last of all. what holds the
779 * class of device in the upper byte and the device number (0xFF for
780 * all) for the object to be transitioned.
782 * The state holds the state to transition to, which may in fact
783 * be an acceptance of a BIOS requested state change.
786 static int set_power_state(u_short what, u_short state)
791 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
797 * set_system_power_state - set system wide power state
798 * @state: which state to enter
800 * Transition the entire system into a new APM power state.
803 static int set_system_power_state(u_short state)
805 return set_power_state(APM_DEVICE_ALL, state);
809 * apm_do_idle - perform power saving
811 * This function notifies the BIOS that the processor is (in the view
812 * of the OS) idle. It returns -1 in the event that the BIOS refuses
813 * to handle the idle request. On a success the function returns 1
814 * if the BIOS did clock slowing or 0 otherwise.
817 static int apm_do_idle(void)
825 polling = !!(current_thread_info()->status & TS_POLLING);
827 current_thread_info()->status &= ~TS_POLLING;
829 * TS_POLLING-cleared state must be visible before we
834 if (!need_resched()) {
836 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
839 current_thread_info()->status |= TS_POLLING;
845 static unsigned long t;
847 /* This always fails on some SMP boards running UP kernels.
848 * Only report the failure the first 5 times.
851 printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
856 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
861 * apm_do_busy - inform the BIOS the CPU is busy
863 * Request that the BIOS brings the CPU back to full performance.
866 static void apm_do_busy(void)
871 if (clock_slowed || ALWAYS_CALL_BUSY) {
872 (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
878 * If no process has really been interested in
879 * the CPU for some time, we want to call BIOS
880 * power management - we probably want
883 #define IDLE_CALC_LIMIT (HZ * 100)
884 #define IDLE_LEAKY_MAX 16
886 static void (*original_pm_idle)(void) __read_mostly;
889 * apm_cpu_idle - cpu idling for APM capable Linux
891 * This is the idling function the kernel executes when APM is available. It
892 * tries to do BIOS powermanagement based on the average system idle time.
893 * Furthermore it calls the system default idle routine.
896 static void apm_cpu_idle(void)
898 static int use_apm_idle; /* = 0 */
899 static unsigned int last_jiffies; /* = 0 */
900 static unsigned int last_stime; /* = 0 */
902 int apm_idle_done = 0;
903 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
907 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
909 last_jiffies = jiffies;
910 last_stime = current->stime;
911 } else if (jiffies_since_last_check > idle_period) {
912 unsigned int idle_percentage;
914 idle_percentage = current->stime - last_stime;
915 idle_percentage *= 100;
916 idle_percentage /= jiffies_since_last_check;
917 use_apm_idle = (idle_percentage > idle_threshold);
918 if (apm_info.forbid_idle)
920 last_jiffies = jiffies;
921 last_stime = current->stime;
924 bucket = IDLE_LEAKY_MAX;
926 while (!need_resched()) {
931 switch (apm_do_idle()) {
936 bucket = IDLE_LEAKY_MAX;
947 default: /* BIOS refused */
951 if (original_pm_idle)
956 jiffies_since_last_check = jiffies - last_jiffies;
957 if (jiffies_since_last_check > idle_period)
968 * apm_power_off - ask the BIOS to power off
970 * Handle the power off sequence. This is the one piece of code we
971 * will execute even on SMP machines. In order to deal with BIOS
972 * bugs we support real mode APM BIOS power off calls. We also make
973 * the SMP call on CPU0 as some systems will only honour this call
974 * on their first cpu.
977 static void apm_power_off(void)
979 unsigned char po_bios_call[] = {
980 0xb8, 0x00, 0x10, /* movw $0x1000,ax */
981 0x8e, 0xd0, /* movw ax,ss */
982 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */
983 0xb8, 0x07, 0x53, /* movw $0x5307,ax */
984 0xbb, 0x01, 0x00, /* movw $0x0001,bx */
985 0xb9, 0x03, 0x00, /* movw $0x0003,cx */
986 0xcd, 0x15 /* int $0x15 */
989 /* Some bioses don't like being called from CPU != 0 */
990 if (apm_info.realmode_power_off) {
991 set_cpus_allowed_ptr(current, cpumask_of(0));
992 machine_real_restart(po_bios_call, sizeof(po_bios_call));
994 (void)set_system_power_state(APM_STATE_OFF);
998 #ifdef CONFIG_APM_DO_ENABLE
1001 * apm_enable_power_management - enable BIOS APM power management
1002 * @enable: enable yes/no
1004 * Enable or disable the APM BIOS power services.
1007 static int apm_enable_power_management(int enable)
1012 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1013 return APM_NOT_ENGAGED;
1014 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1015 enable, &eax, &err))
1018 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1020 apm_info.bios.flags |= APM_BIOS_DISABLED;
1026 * apm_get_power_status - get current power state
1027 * @status: returned status
1028 * @bat: battery info
1029 * @life: estimated life
1031 * Obtain the current power status from the APM BIOS. We return a
1032 * status which gives the rough battery status, and current power
1033 * source. The bat value returned give an estimate as a percentage
1034 * of life and a status value for the battery. The estimated life
1035 * if reported is a lifetime in secodnds/minutes at current powwer
1039 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1041 struct apm_bios_call call;
1043 call.func = APM_FUNC_GET_STATUS;
1044 call.ebx = APM_DEVICE_ALL;
1047 if (apm_info.get_power_status_broken)
1048 return APM_32_UNSUPPORTED;
1049 if (apm_bios_call(&call))
1053 if (apm_info.get_power_status_swabinminutes) {
1054 *life = swab16((u16)call.edx);
1062 static int apm_get_battery_status(u_short which, u_short *status,
1063 u_short *bat, u_short *life, u_short *nbat)
1071 if (apm_info.connection_version < 0x0102) {
1072 /* pretend we only have one battery. */
1074 return APM_BAD_DEVICE;
1076 return apm_get_power_status(status, bat, life);
1079 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1080 &ebx, &ecx, &edx, &esi))
1081 return (eax >> 8) & 0xff;
1091 * apm_engage_power_management - enable PM on a device
1092 * @device: identity of device
1095 * Activate or deactive power management on either a specific device
1096 * or the entire system (%APM_DEVICE_ALL).
1099 static int apm_engage_power_management(u_short device, int enable)
1104 if ((enable == 0) && (device == APM_DEVICE_ALL)
1105 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1106 return APM_DISABLED;
1107 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1110 if (device == APM_DEVICE_ALL) {
1112 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1114 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1119 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1122 * apm_console_blank - blank the display
1125 * Attempt to blank the console, firstly by blanking just video device
1126 * zero, and if that fails (some BIOSes don't support it) then it blanks
1127 * all video devices. Typically the BIOS will do laptop backlight and
1128 * monitor powerdown for us.
1131 static int apm_console_blank(int blank)
1133 int error = APM_NOT_ENGAGED; /* silence gcc */
1136 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1138 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1140 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1141 error = set_power_state(dev[i], state);
1143 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1146 if (error == APM_NOT_ENGAGED)
1150 if (error == APM_NOT_ENGAGED) {
1154 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1156 apm_error("set display", error);
1157 apm_error("engage interface", eng_error);
1160 return apm_console_blank(blank);
1163 apm_error("set display", error);
1168 static int queue_empty(struct apm_user *as)
1170 return as->event_head == as->event_tail;
1173 static apm_event_t get_queued_event(struct apm_user *as)
1175 if (++as->event_tail >= APM_MAX_EVENTS)
1177 return as->events[as->event_tail];
1180 static void queue_event(apm_event_t event, struct apm_user *sender)
1182 struct apm_user *as;
1184 spin_lock(&user_list_lock);
1185 if (user_list == NULL)
1187 for (as = user_list; as != NULL; as = as->next) {
1188 if ((as == sender) || (!as->reader))
1190 if (++as->event_head >= APM_MAX_EVENTS)
1193 if (as->event_head == as->event_tail) {
1194 static int notified;
1196 if (notified++ == 0)
1197 printk(KERN_ERR "apm: an event queue overflowed\n");
1198 if (++as->event_tail >= APM_MAX_EVENTS)
1201 as->events[as->event_head] = event;
1202 if (!as->suser || !as->writer)
1205 case APM_SYS_SUSPEND:
1206 case APM_USER_SUSPEND:
1207 as->suspends_pending++;
1211 case APM_SYS_STANDBY:
1212 case APM_USER_STANDBY:
1213 as->standbys_pending++;
1218 wake_up_interruptible(&apm_waitqueue);
1220 spin_unlock(&user_list_lock);
1223 static void reinit_timer(void)
1225 #ifdef INIT_TIMER_AFTER_SUSPEND
1226 unsigned long flags;
1228 raw_spin_lock_irqsave(&i8253_lock, flags);
1229 /* set the clock to HZ */
1230 outb_pit(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1232 outb_pit(LATCH & 0xff, PIT_CH0); /* LSB */
1234 outb_pit(LATCH >> 8, PIT_CH0); /* MSB */
1236 raw_spin_unlock_irqrestore(&i8253_lock, flags);
1240 static int suspend(int vetoable)
1243 struct apm_user *as;
1245 dpm_suspend_start(PMSG_SUSPEND);
1247 dpm_suspend_noirq(PMSG_SUSPEND);
1249 local_irq_disable();
1250 sysdev_suspend(PMSG_SUSPEND);
1254 save_processor_state();
1255 err = set_system_power_state(APM_STATE_SUSPEND);
1256 ignore_normal_resume = 1;
1257 restore_processor_state();
1259 local_irq_disable();
1262 if (err == APM_NO_ERROR)
1264 if (err != APM_SUCCESS)
1265 apm_error("suspend", err);
1266 err = (err == APM_SUCCESS) ? 0 : -EIO;
1271 dpm_resume_noirq(PMSG_RESUME);
1273 dpm_resume_end(PMSG_RESUME);
1274 queue_event(APM_NORMAL_RESUME, NULL);
1275 spin_lock(&user_list_lock);
1276 for (as = user_list; as != NULL; as = as->next) {
1277 as->suspend_wait = 0;
1278 as->suspend_result = err;
1280 spin_unlock(&user_list_lock);
1281 wake_up_interruptible(&apm_suspend_waitqueue);
1285 static void standby(void)
1289 dpm_suspend_noirq(PMSG_SUSPEND);
1291 local_irq_disable();
1292 sysdev_suspend(PMSG_SUSPEND);
1295 err = set_system_power_state(APM_STATE_STANDBY);
1296 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1297 apm_error("standby", err);
1299 local_irq_disable();
1303 dpm_resume_noirq(PMSG_RESUME);
1306 static apm_event_t get_event(void)
1309 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1310 apm_eventinfo_t info;
1312 static int notified;
1314 /* we don't use the eventinfo */
1315 error = apm_get_event(&event, &info);
1316 if (error == APM_SUCCESS)
1319 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1320 apm_error("get_event", error);
1325 static void check_events(void)
1328 static unsigned long last_resume;
1329 static int ignore_bounce;
1331 while ((event = get_event()) != 0) {
1333 if (event <= NR_APM_EVENT_NAME)
1334 printk(KERN_DEBUG "apm: received %s notify\n",
1335 apm_event_name[event - 1]);
1337 printk(KERN_DEBUG "apm: received unknown "
1338 "event 0x%02x\n", event);
1341 && (time_after(jiffies, last_resume + bounce_interval)))
1345 case APM_SYS_STANDBY:
1346 case APM_USER_STANDBY:
1347 queue_event(event, NULL);
1348 if (standbys_pending <= 0)
1352 case APM_USER_SUSPEND:
1353 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1354 if (apm_info.connection_version > 0x100)
1355 set_system_power_state(APM_STATE_REJECT);
1358 case APM_SYS_SUSPEND:
1359 if (ignore_bounce) {
1360 if (apm_info.connection_version > 0x100)
1361 set_system_power_state(APM_STATE_REJECT);
1365 * If we are already processing a SUSPEND,
1366 * then further SUSPEND events from the BIOS
1367 * will be ignored. We also return here to
1368 * cope with the fact that the Thinkpads keep
1369 * sending a SUSPEND event until something else
1372 if (ignore_sys_suspend)
1374 ignore_sys_suspend = 1;
1375 queue_event(event, NULL);
1376 if (suspends_pending <= 0)
1380 case APM_NORMAL_RESUME:
1381 case APM_CRITICAL_RESUME:
1382 case APM_STANDBY_RESUME:
1383 ignore_sys_suspend = 0;
1384 last_resume = jiffies;
1386 if ((event != APM_NORMAL_RESUME)
1387 || (ignore_normal_resume == 0)) {
1388 dpm_resume_end(PMSG_RESUME);
1389 queue_event(event, NULL);
1391 ignore_normal_resume = 0;
1394 case APM_CAPABILITY_CHANGE:
1395 case APM_LOW_BATTERY:
1396 case APM_POWER_STATUS_CHANGE:
1397 queue_event(event, NULL);
1398 /* If needed, notify drivers here */
1401 case APM_UPDATE_TIME:
1404 case APM_CRITICAL_SUSPEND:
1406 * We are not allowed to reject a critical suspend.
1414 static void apm_event_handler(void)
1416 static int pending_count = 4;
1419 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1420 if ((apm_info.connection_version > 0x100) &&
1421 (pending_count-- <= 0)) {
1424 printk(KERN_DEBUG "apm: setting state busy\n");
1425 err = set_system_power_state(APM_STATE_BUSY);
1427 apm_error("busy", err);
1435 * This is the APM thread main loop.
1438 static void apm_mainloop(void)
1440 DECLARE_WAITQUEUE(wait, current);
1442 add_wait_queue(&apm_waitqueue, &wait);
1443 set_current_state(TASK_INTERRUPTIBLE);
1445 schedule_timeout(APM_CHECK_TIMEOUT);
1446 if (kthread_should_stop())
1449 * Ok, check all events, check for idle (and mark us sleeping
1450 * so as not to count towards the load average)..
1452 set_current_state(TASK_INTERRUPTIBLE);
1453 apm_event_handler();
1455 remove_wait_queue(&apm_waitqueue, &wait);
1458 static int check_apm_user(struct apm_user *as, const char *func)
1460 if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1461 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1467 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1469 struct apm_user *as;
1473 as = fp->private_data;
1474 if (check_apm_user(as, "read"))
1476 if ((int)count < sizeof(apm_event_t))
1478 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1480 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1482 while ((i >= sizeof(event)) && !queue_empty(as)) {
1483 event = get_queued_event(as);
1484 if (copy_to_user(buf, &event, sizeof(event))) {
1490 case APM_SYS_SUSPEND:
1491 case APM_USER_SUSPEND:
1492 as->suspends_read++;
1495 case APM_SYS_STANDBY:
1496 case APM_USER_STANDBY:
1497 as->standbys_read++;
1500 buf += sizeof(event);
1505 if (signal_pending(current))
1506 return -ERESTARTSYS;
1510 static unsigned int do_poll(struct file *fp, poll_table *wait)
1512 struct apm_user *as;
1514 as = fp->private_data;
1515 if (check_apm_user(as, "poll"))
1517 poll_wait(fp, &apm_waitqueue, wait);
1518 if (!queue_empty(as))
1519 return POLLIN | POLLRDNORM;
1523 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1525 struct apm_user *as;
1528 as = filp->private_data;
1529 if (check_apm_user(as, "ioctl"))
1531 if (!as->suser || !as->writer)
1534 case APM_IOC_STANDBY:
1535 mutex_lock(&apm_mutex);
1536 if (as->standbys_read > 0) {
1537 as->standbys_read--;
1538 as->standbys_pending--;
1541 queue_event(APM_USER_STANDBY, as);
1542 if (standbys_pending <= 0)
1544 mutex_unlock(&apm_mutex);
1546 case APM_IOC_SUSPEND:
1547 mutex_lock(&apm_mutex);
1548 if (as->suspends_read > 0) {
1549 as->suspends_read--;
1550 as->suspends_pending--;
1553 queue_event(APM_USER_SUSPEND, as);
1554 if (suspends_pending <= 0) {
1556 mutex_unlock(&apm_mutex);
1558 as->suspend_wait = 1;
1559 mutex_unlock(&apm_mutex);
1560 wait_event_interruptible(apm_suspend_waitqueue,
1561 as->suspend_wait == 0);
1562 ret = as->suspend_result;
1571 static int do_release(struct inode *inode, struct file *filp)
1573 struct apm_user *as;
1575 as = filp->private_data;
1576 if (check_apm_user(as, "release"))
1578 filp->private_data = NULL;
1579 if (as->standbys_pending > 0) {
1580 standbys_pending -= as->standbys_pending;
1581 if (standbys_pending <= 0)
1584 if (as->suspends_pending > 0) {
1585 suspends_pending -= as->suspends_pending;
1586 if (suspends_pending <= 0)
1589 spin_lock(&user_list_lock);
1590 if (user_list == as)
1591 user_list = as->next;
1593 struct apm_user *as1;
1595 for (as1 = user_list;
1596 (as1 != NULL) && (as1->next != as);
1600 printk(KERN_ERR "apm: filp not in user list\n");
1602 as1->next = as->next;
1604 spin_unlock(&user_list_lock);
1609 static int do_open(struct inode *inode, struct file *filp)
1611 struct apm_user *as;
1613 as = kmalloc(sizeof(*as), GFP_KERNEL);
1615 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1619 as->magic = APM_BIOS_MAGIC;
1620 as->event_tail = as->event_head = 0;
1621 as->suspends_pending = as->standbys_pending = 0;
1622 as->suspends_read = as->standbys_read = 0;
1624 * XXX - this is a tiny bit broken, when we consider BSD
1625 * process accounting. If the device is opened by root, we
1626 * instantly flag that we used superuser privs. Who knows,
1627 * we might close the device immediately without doing a
1628 * privileged operation -- cevans
1630 as->suser = capable(CAP_SYS_ADMIN);
1631 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1632 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1633 spin_lock(&user_list_lock);
1634 as->next = user_list;
1636 spin_unlock(&user_list_lock);
1637 filp->private_data = as;
1641 static int proc_apm_show(struct seq_file *m, void *v)
1647 unsigned short ac_line_status = 0xff;
1648 unsigned short battery_status = 0xff;
1649 unsigned short battery_flag = 0xff;
1650 int percentage = -1;
1651 int time_units = -1;
1654 if ((num_online_cpus() == 1) &&
1655 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1656 ac_line_status = (bx >> 8) & 0xff;
1657 battery_status = bx & 0xff;
1658 if ((cx & 0xff) != 0xff)
1659 percentage = cx & 0xff;
1661 if (apm_info.connection_version > 0x100) {
1662 battery_flag = (cx >> 8) & 0xff;
1664 units = (dx & 0x8000) ? "min" : "sec";
1665 time_units = dx & 0x7fff;
1669 /* Arguments, with symbols from linux/apm_bios.h. Information is
1670 from the Get Power Status (0x0a) call unless otherwise noted.
1672 0) Linux driver version (this will change if format changes)
1673 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1674 2) APM flags from APM Installation Check (0x00):
1675 bit 0: APM_16_BIT_SUPPORT
1676 bit 1: APM_32_BIT_SUPPORT
1677 bit 2: APM_IDLE_SLOWS_CLOCK
1678 bit 3: APM_BIOS_DISABLED
1679 bit 4: APM_BIOS_DISENGAGED
1683 0x02: On backup power (BIOS >= 1.1 only)
1690 0x04: Selected battery not present (BIOS >= 1.2 only)
1697 bit 7: No system battery
1699 6) Remaining battery life (percentage of charge):
1702 7) Remaining battery life (time units):
1703 Number of remaining minutes or seconds
1705 8) min = minutes; sec = seconds */
1707 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1709 (apm_info.bios.version >> 8) & 0xff,
1710 apm_info.bios.version & 0xff,
1711 apm_info.bios.flags,
1721 static int proc_apm_open(struct inode *inode, struct file *file)
1723 return single_open(file, proc_apm_show, NULL);
1726 static const struct file_operations apm_file_ops = {
1727 .owner = THIS_MODULE,
1728 .open = proc_apm_open,
1730 .llseek = seq_lseek,
1731 .release = single_release,
1734 static int apm(void *unused)
1744 * This is to avoid random crashes at boot time during initialization
1745 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1746 * Some bioses don't like being called from CPU != 0.
1747 * Method suggested by Ingo Molnar.
1749 set_cpus_allowed_ptr(current, cpumask_of(0));
1750 BUG_ON(smp_processor_id() != 0);
1752 if (apm_info.connection_version == 0) {
1753 apm_info.connection_version = apm_info.bios.version;
1754 if (apm_info.connection_version > 0x100) {
1756 * We only support BIOSs up to version 1.2
1758 if (apm_info.connection_version > 0x0102)
1759 apm_info.connection_version = 0x0102;
1760 error = apm_driver_version(&apm_info.connection_version);
1761 if (error != APM_SUCCESS) {
1762 apm_error("driver version", error);
1763 /* Fall back to an APM 1.0 connection. */
1764 apm_info.connection_version = 0x100;
1770 printk(KERN_INFO "apm: Connection version %d.%d\n",
1771 (apm_info.connection_version >> 8) & 0xff,
1772 apm_info.connection_version & 0xff);
1774 #ifdef CONFIG_APM_DO_ENABLE
1775 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1777 * This call causes my NEC UltraLite Versa 33/C to hang if it
1778 * is booted with PM disabled but not in the docking station.
1781 error = apm_enable_power_management(1);
1783 apm_error("enable power management", error);
1789 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1790 && (apm_info.connection_version > 0x0100)) {
1791 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1793 apm_error("engage power management", error);
1798 if (debug && (num_online_cpus() == 1 || smp)) {
1799 error = apm_get_power_status(&bx, &cx, &dx);
1801 printk(KERN_INFO "apm: power status not available\n");
1803 switch ((bx >> 8) & 0xff) {
1805 power_stat = "off line";
1808 power_stat = "on line";
1811 power_stat = "on backup power";
1814 power_stat = "unknown";
1817 switch (bx & 0xff) {
1825 bat_stat = "critical";
1828 bat_stat = "charging";
1831 bat_stat = "unknown";
1835 "apm: AC %s, battery status %s, battery life ",
1836 power_stat, bat_stat);
1837 if ((cx & 0xff) == 0xff)
1838 printk("unknown\n");
1840 printk("%d%%\n", cx & 0xff);
1841 if (apm_info.connection_version > 0x100) {
1843 "apm: battery flag 0x%02x, battery life ",
1846 printk("unknown\n");
1848 printk("%d %s\n", dx & 0x7fff,
1850 "minutes" : "seconds");
1855 /* Install our power off handler.. */
1857 pm_power_off = apm_power_off;
1859 if (num_online_cpus() == 1 || smp) {
1860 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1861 console_blank_hook = apm_console_blank;
1864 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1865 console_blank_hook = NULL;
1873 static int __init apm_setup(char *str)
1877 while ((str != NULL) && (*str != '\0')) {
1878 if (strncmp(str, "off", 3) == 0)
1880 if (strncmp(str, "on", 2) == 0)
1882 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1883 (strncmp(str, "bounce_interval=", 16) == 0))
1884 bounce_interval = simple_strtol(str + 16, NULL, 0);
1885 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1886 (strncmp(str, "idle_threshold=", 15) == 0))
1887 idle_threshold = simple_strtol(str + 15, NULL, 0);
1888 if ((strncmp(str, "idle-period=", 12) == 0) ||
1889 (strncmp(str, "idle_period=", 12) == 0))
1890 idle_period = simple_strtol(str + 12, NULL, 0);
1891 invert = (strncmp(str, "no-", 3) == 0) ||
1892 (strncmp(str, "no_", 3) == 0);
1895 if (strncmp(str, "debug", 5) == 0)
1897 if ((strncmp(str, "power-off", 9) == 0) ||
1898 (strncmp(str, "power_off", 9) == 0))
1899 power_off = !invert;
1900 if (strncmp(str, "smp", 3) == 0) {
1902 idle_threshold = 100;
1904 if ((strncmp(str, "allow-ints", 10) == 0) ||
1905 (strncmp(str, "allow_ints", 10) == 0))
1906 apm_info.allow_ints = !invert;
1907 if ((strncmp(str, "broken-psr", 10) == 0) ||
1908 (strncmp(str, "broken_psr", 10) == 0))
1909 apm_info.get_power_status_broken = !invert;
1910 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1911 (strncmp(str, "realmode_power_off", 18) == 0))
1912 apm_info.realmode_power_off = !invert;
1913 str = strchr(str, ',');
1915 str += strspn(str, ", \t");
1920 __setup("apm=", apm_setup);
1923 static const struct file_operations apm_bios_fops = {
1924 .owner = THIS_MODULE,
1927 .unlocked_ioctl = do_ioctl,
1929 .release = do_release,
1930 .llseek = noop_llseek,
1933 static struct miscdevice apm_device = {
1940 /* Simple "print if true" callback */
1941 static int __init print_if_true(const struct dmi_system_id *d)
1943 printk("%s\n", d->ident);
1948 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1949 * disabled before the suspend. Linux used to get terribly confused by that.
1951 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1953 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1954 "workaround hopefully not needed.\n", d->ident);
1958 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1959 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1961 if (apm_info.realmode_power_off == 0) {
1962 apm_info.realmode_power_off = 1;
1963 printk(KERN_INFO "%s bios detected. "
1964 "Using realmode poweroff only.\n", d->ident);
1969 /* Some laptops require interrupts to be enabled during APM calls */
1970 static int __init set_apm_ints(const struct dmi_system_id *d)
1972 if (apm_info.allow_ints == 0) {
1973 apm_info.allow_ints = 1;
1974 printk(KERN_INFO "%s machine detected. "
1975 "Enabling interrupts during APM calls.\n", d->ident);
1980 /* Some APM bioses corrupt memory or just plain do not work */
1981 static int __init apm_is_horked(const struct dmi_system_id *d)
1983 if (apm_info.disabled == 0) {
1984 apm_info.disabled = 1;
1985 printk(KERN_INFO "%s machine detected. "
1986 "Disabling APM.\n", d->ident);
1991 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1993 if (apm_info.disabled == 0) {
1994 apm_info.disabled = 1;
1995 printk(KERN_INFO "%s machine detected. "
1996 "Disabling APM.\n", d->ident);
1997 printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1998 printk(KERN_INFO "download from support.intel.com\n");
2003 /* Some APM bioses hang on APM idle calls */
2004 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2006 if (apm_info.forbid_idle == 0) {
2007 apm_info.forbid_idle = 1;
2008 printk(KERN_INFO "%s machine detected. "
2009 "Disabling APM idle calls.\n", d->ident);
2015 * Check for clue free BIOS implementations who use
2016 * the following QA technique
2018 * [ Write BIOS Code ]<------
2020 * < Does it Compile >----N--
2022 * < Does it Boot Win98 >-N--
2026 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
2027 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
2029 static int __init broken_apm_power(const struct dmi_system_id *d)
2031 apm_info.get_power_status_broken = 1;
2032 printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2033 "disabling power status reporting.\n");
2038 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2039 * have this problem).
2041 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2043 apm_info.get_power_status_swabinminutes = 1;
2044 printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2045 "in minutes and wrong byte order.\n");
2049 static struct dmi_system_id __initdata apm_dmi_table[] = {
2052 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2053 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2054 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2056 { /* Handle problems with APM on the C600 */
2057 broken_ps2_resume, "Dell Latitude C600",
2058 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2059 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2061 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2062 set_apm_ints, "Dell Latitude",
2063 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2064 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2067 apm_is_horked, "Dell Inspiron 2500",
2068 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2069 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2070 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2071 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2073 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2074 set_apm_ints, "Dell Inspiron", {
2075 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2076 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2078 { /* Handle problems with APM on Inspiron 5000e */
2079 broken_apm_power, "Dell Inspiron 5000e",
2080 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2081 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2082 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2084 { /* Handle problems with APM on Inspiron 2500 */
2085 broken_apm_power, "Dell Inspiron 2500",
2086 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2087 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2088 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2091 apm_is_horked, "Dell Dimension 4100",
2092 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2093 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2094 DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2095 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2097 { /* Allow interrupts during suspend on Compaq Laptops*/
2098 set_apm_ints, "Compaq 12XL125",
2099 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2100 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2101 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2102 DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2104 { /* Allow interrupts during APM or the clock goes slow */
2105 set_apm_ints, "ASUSTeK",
2106 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2107 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2109 { /* APM blows on shutdown */
2110 apm_is_horked, "ABIT KX7-333[R]",
2111 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2112 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2115 apm_is_horked, "Trigem Delhi3",
2116 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2117 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2120 apm_is_horked, "Fujitsu-Siemens",
2121 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2122 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2125 apm_is_horked_d850md, "Intel D850MD",
2126 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2127 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2130 apm_is_horked, "Intel D810EMO",
2131 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2132 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2135 apm_is_horked, "Dell XPS-Z",
2136 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2137 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2138 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2141 apm_is_horked, "Sharp PC-PJ/AX",
2142 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2143 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2144 DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2145 DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2148 apm_is_horked, "Dell Inspiron 2500",
2149 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2150 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2151 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2152 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2154 { /* APM idle hangs */
2155 apm_likes_to_melt, "Jabil AMD",
2156 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2157 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2159 { /* APM idle hangs */
2160 apm_likes_to_melt, "AMI Bios",
2161 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2162 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2164 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2165 swab_apm_power_in_minutes, "Sony VAIO",
2166 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2167 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2168 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2170 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2171 swab_apm_power_in_minutes, "Sony VAIO",
2172 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2173 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2174 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2176 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2177 swab_apm_power_in_minutes, "Sony VAIO",
2178 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2179 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2180 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2182 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2183 swab_apm_power_in_minutes, "Sony VAIO",
2184 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2185 DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2186 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2188 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2189 swab_apm_power_in_minutes, "Sony VAIO",
2190 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2191 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2192 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2194 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2195 swab_apm_power_in_minutes, "Sony VAIO",
2196 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2197 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2198 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2200 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2201 swab_apm_power_in_minutes, "Sony VAIO",
2202 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2203 DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2204 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2206 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2207 swab_apm_power_in_minutes, "Sony VAIO",
2208 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2209 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2210 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2212 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2213 swab_apm_power_in_minutes, "Sony VAIO",
2214 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2215 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2216 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2218 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2219 swab_apm_power_in_minutes, "Sony VAIO",
2220 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2221 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2222 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2225 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2226 swab_apm_power_in_minutes, "Sony VAIO",
2227 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2228 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2229 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2231 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2232 swab_apm_power_in_minutes, "Sony VAIO",
2233 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2234 DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2235 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2237 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2238 swab_apm_power_in_minutes, "Sony VAIO",
2239 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2240 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2241 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2243 { /* broken PM poweroff bios */
2244 set_realmode_power_off, "Award Software v4.60 PGMA",
2245 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2246 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2247 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2250 /* Generic per vendor APM settings */
2252 { /* Allow interrupts during suspend on IBM laptops */
2253 set_apm_ints, "IBM",
2254 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2261 * Just start the APM thread. We do NOT want to do APM BIOS
2262 * calls from anything but the APM thread, if for no other reason
2263 * than the fact that we don't trust the APM BIOS. This way,
2264 * most common APM BIOS problems that lead to protection errors
2265 * etc will have at least some level of being contained...
2267 * In short, if something bad happens, at least we have a choice
2268 * of just killing the apm thread..
2270 static int __init apm_init(void)
2272 struct desc_struct *gdt;
2275 dmi_check_system(apm_dmi_table);
2277 if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2278 printk(KERN_INFO "apm: BIOS not found.\n");
2282 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2283 ((apm_info.bios.version >> 8) & 0xff),
2284 (apm_info.bios.version & 0xff),
2285 apm_info.bios.flags,
2287 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2288 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2293 apm_info.allow_ints = 1;
2295 apm_info.get_power_status_broken = 1;
2296 if (realmode_power_off)
2297 apm_info.realmode_power_off = 1;
2298 /* User can override, but default is to trust DMI */
2299 if (apm_disabled != -1)
2300 apm_info.disabled = apm_disabled;
2303 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2304 * but is reportedly a 1.0 BIOS.
2306 if (apm_info.bios.version == 0x001)
2307 apm_info.bios.version = 0x100;
2309 /* BIOS < 1.2 doesn't set cseg_16_len */
2310 if (apm_info.bios.version < 0x102)
2311 apm_info.bios.cseg_16_len = 0; /* 64k */
2314 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2315 apm_info.bios.cseg, apm_info.bios.offset,
2316 apm_info.bios.cseg_16, apm_info.bios.dseg);
2317 if (apm_info.bios.version > 0x100)
2318 printk(" cseg len %x, dseg len %x",
2319 apm_info.bios.cseg_len,
2320 apm_info.bios.dseg_len);
2321 if (apm_info.bios.version > 0x101)
2322 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2326 if (apm_info.disabled) {
2327 printk(KERN_NOTICE "apm: disabled on user request.\n");
2330 if ((num_online_cpus() > 1) && !power_off && !smp) {
2331 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2332 apm_info.disabled = 1;
2335 if (!acpi_disabled) {
2336 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2337 apm_info.disabled = 1;
2342 * Set up the long jump entry point to the APM BIOS, which is called
2343 * from inline assembly.
2345 apm_bios_entry.offset = apm_info.bios.offset;
2346 apm_bios_entry.segment = APM_CS;
2349 * The APM 1.1 BIOS is supposed to provide limit information that it
2350 * recognizes. Many machines do this correctly, but many others do
2351 * not restrict themselves to their claimed limit. When this happens,
2352 * they will cause a segmentation violation in the kernel at boot time.
2353 * Most BIOS's, however, will respect a 64k limit, so we use that.
2355 * Note we only set APM segments on CPU zero, since we pin the APM
2358 gdt = get_cpu_gdt_table(0);
2359 set_desc_base(&gdt[APM_CS >> 3],
2360 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2361 set_desc_base(&gdt[APM_CS_16 >> 3],
2362 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2363 set_desc_base(&gdt[APM_DS >> 3],
2364 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2366 proc_create("apm", 0, NULL, &apm_file_ops);
2368 kapmd_task = kthread_create(apm, NULL, "kapmd");
2369 if (IS_ERR(kapmd_task)) {
2370 printk(KERN_ERR "apm: disabled - Unable to start kernel "
2372 err = PTR_ERR(kapmd_task);
2374 remove_proc_entry("apm", NULL);
2377 wake_up_process(kapmd_task);
2379 if (num_online_cpus() > 1 && !smp) {
2381 "apm: disabled - APM is not SMP safe (power off active).\n");
2386 * Note we don't actually care if the misc_device cannot be registered.
2387 * this driver can do its job without it, even if userspace can't
2388 * control it. just log the error
2390 if (misc_register(&apm_device))
2391 printk(KERN_WARNING "apm: Could not register misc device.\n");
2394 idle_period = (idle_period * HZ) / 100;
2395 if (idle_threshold < 100) {
2396 original_pm_idle = pm_idle;
2397 pm_idle = apm_cpu_idle;
2404 static void __exit apm_exit(void)
2409 pm_idle = original_pm_idle;
2411 * We are about to unload the current idle thread pm callback
2412 * (pm_idle), Wait for all processors to update cached/local
2413 * copies of pm_idle before proceeding.
2417 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2418 && (apm_info.connection_version > 0x0100)) {
2419 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2421 apm_error("disengage power management", error);
2423 misc_deregister(&apm_device);
2424 remove_proc_entry("apm", NULL);
2426 pm_power_off = NULL;
2428 kthread_stop(kapmd_task);
2433 module_init(apm_init);
2434 module_exit(apm_exit);
2436 MODULE_AUTHOR("Stephen Rothwell");
2437 MODULE_DESCRIPTION("Advanced Power Management");
2438 MODULE_LICENSE("GPL");
2439 module_param(debug, bool, 0644);
2440 MODULE_PARM_DESC(debug, "Enable debug mode");
2441 module_param(power_off, bool, 0444);
2442 MODULE_PARM_DESC(power_off, "Enable power off");
2443 module_param(bounce_interval, int, 0444);
2444 MODULE_PARM_DESC(bounce_interval,
2445 "Set the number of ticks to ignore suspend bounces");
2446 module_param(allow_ints, bool, 0444);
2447 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2448 module_param(broken_psr, bool, 0444);
2449 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2450 module_param(realmode_power_off, bool, 0444);
2451 MODULE_PARM_DESC(realmode_power_off,
2452 "Switch to real mode before powering off");
2453 module_param(idle_threshold, int, 0444);
2454 MODULE_PARM_DESC(idle_threshold,
2455 "System idle percentage above which to make APM BIOS idle calls");
2456 module_param(idle_period, int, 0444);
2457 MODULE_PARM_DESC(idle_period,
2458 "Period (in sec/100) over which to caculate the idle percentage");
2459 module_param(smp, bool, 0444);
2460 MODULE_PARM_DESC(smp,
2461 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2462 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);