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/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/pm_legacy.h>
222 #include <linux/capability.h>
223 #include <linux/device.h>
224 #include <linux/kernel.h>
225 #include <linux/smp.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>
234 #include <asm/paravirt.h>
235 #include <asm/reboot.h>
237 #include "io_ports.h"
239 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
240 extern int (*console_blank_hook)(int);
244 * The apm_bios device is one of the misc char devices.
245 * This is its minor number.
247 #define APM_MINOR_DEV 134
250 * See Documentation/Config.help for the configuration options.
252 * Various options can be changed at boot time as follows:
253 * (We allow underscores for compatibility with the modules code)
254 * apm=on/off enable/disable APM
255 * [no-]allow[-_]ints allow interrupts during BIOS calls
256 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
257 * [no-]realmode[-_]power[-_]off switch to real mode before
259 * [no-]debug log some debugging messages
260 * [no-]power[-_]off power off on shutdown
261 * [no-]smp Use apm even on an SMP box
262 * bounce[-_]interval=<n> number of ticks to ignore suspend
264 * idle[-_]threshold=<n> System idle percentage above which to
265 * make APM BIOS idle calls. Set it to
267 * idle[-_]period=<n> Period (in 1/100s of a second) over
268 * which the idle percentage is
272 /* KNOWN PROBLEM MACHINES:
274 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
275 * [Confirmed by TI representative]
276 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
277 * [Confirmed by BIOS disassembly]
278 * [This may work now ...]
279 * P: Toshiba 1950S: battery life information only gets updated after resume
280 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
281 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
282 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
283 * Neale Banks <neale@lowendale.com.au> December 2000
285 * Legend: U = unusable with APM patches
286 * P = partially usable with APM patches
290 * Define as 1 to make the driver always call the APM BIOS busy
291 * routine even if the clock was not reported as slowed by the
292 * idle routine. Otherwise, define as 0.
294 #define ALWAYS_CALL_BUSY 1
297 * Define to make the APM BIOS calls zero all data segment registers (so
298 * that an incorrect BIOS implementation will cause a kernel panic if it
299 * tries to write to arbitrary memory).
301 #define APM_ZERO_SEGS
306 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
307 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
308 * David Chen <chen@ctpa04.mit.edu>
310 #undef INIT_TIMER_AFTER_SUSPEND
312 #ifdef INIT_TIMER_AFTER_SUSPEND
313 #include <linux/timex.h>
315 #include <linux/delay.h>
319 * Need to poll the APM BIOS every second
321 #define APM_CHECK_TIMEOUT (HZ)
324 * Ignore suspend events for this amount of time after a resume
326 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
329 * Maximum number of events stored
331 #define APM_MAX_EVENTS 20
334 * The per-file APM data
338 struct apm_user * next;
339 unsigned int suser: 1;
340 unsigned int writer: 1;
341 unsigned int reader: 1;
342 unsigned int suspend_wait: 1;
344 int suspends_pending;
345 int standbys_pending;
350 apm_event_t events[APM_MAX_EVENTS];
354 * The magic number in apm_user
356 #define APM_BIOS_MAGIC 0x4101
359 * idle percentage above which bios idle calls are done
361 #ifdef CONFIG_APM_CPU_IDLE
362 #define DEFAULT_IDLE_THRESHOLD 95
364 #define DEFAULT_IDLE_THRESHOLD 100
366 #define DEFAULT_IDLE_PERIOD (100 / 3)
372 unsigned long offset;
373 unsigned short segment;
375 static int clock_slowed;
376 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
377 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
378 static int set_pm_idle;
379 static int suspends_pending;
380 static int standbys_pending;
381 static int ignore_sys_suspend;
382 static int ignore_normal_resume;
383 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
385 static int debug __read_mostly;
386 static int smp __read_mostly;
387 static int apm_disabled = -1;
389 static int power_off;
391 static int power_off = 1;
393 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
394 static int realmode_power_off = 1;
396 static int realmode_power_off;
398 #ifdef CONFIG_APM_ALLOW_INTS
399 static int allow_ints = 1;
401 static int allow_ints;
403 static int broken_psr;
405 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
406 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
407 static struct apm_user * user_list;
408 static DEFINE_SPINLOCK(user_list_lock);
409 static const struct desc_struct bad_bios_desc = { 0, 0x00409200 };
411 static const char driver_version[] = "1.16ac"; /* no spaces */
413 static struct task_struct *kapmd_task;
416 * APM event names taken from the APM 1.2 specification. These are
417 * the message codes that the BIOS uses to tell us about events
419 static const char * const apm_event_name[] = {
425 "power status change",
430 "system standby resume",
431 "capabilities change"
433 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
435 typedef struct lookup_t {
441 * The BIOS returns a set of standard error codes in AX when the
445 static const lookup_t error_table[] = {
446 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
447 { APM_DISABLED, "Power management disabled" },
448 { APM_CONNECTED, "Real mode interface already connected" },
449 { APM_NOT_CONNECTED, "Interface not connected" },
450 { APM_16_CONNECTED, "16 bit interface already connected" },
451 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
452 { APM_32_CONNECTED, "32 bit interface already connected" },
453 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
454 { APM_BAD_DEVICE, "Unrecognized device ID" },
455 { APM_BAD_PARAM, "Parameter out of range" },
456 { APM_NOT_ENGAGED, "Interface not engaged" },
457 { APM_BAD_FUNCTION, "Function not supported" },
458 { APM_RESUME_DISABLED, "Resume timer disabled" },
459 { APM_BAD_STATE, "Unable to enter requested state" },
460 /* N/A { APM_NO_EVENTS, "No events pending" }, */
461 { APM_NO_ERROR, "BIOS did not set a return code" },
462 { APM_NOT_PRESENT, "No APM present" }
464 #define ERROR_COUNT ARRAY_SIZE(error_table)
467 * apm_error - display an APM error
468 * @str: information string
469 * @err: APM BIOS return code
471 * Write a meaningful log entry to the kernel log in the event of
475 static void apm_error(char *str, int err)
479 for (i = 0; i < ERROR_COUNT; i++)
480 if (error_table[i].key == err) break;
482 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
484 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
489 * Lock APM functionality to physical CPU 0
494 static cpumask_t apm_save_cpus(void)
496 cpumask_t x = current->cpus_allowed;
497 /* Some bioses don't like being called from CPU != 0 */
498 set_cpus_allowed(current, cpumask_of_cpu(0));
499 BUG_ON(smp_processor_id() != 0);
503 static inline void apm_restore_cpus(cpumask_t mask)
505 set_cpus_allowed(current, mask);
511 * No CPU lockdown needed on a uniprocessor
514 #define apm_save_cpus() (current->cpus_allowed)
515 #define apm_restore_cpus(x) (void)(x)
520 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
521 * apm_info.allow_ints, we are being really paranoid here! Not only
522 * are interrupts disabled, but all the segment registers (except SS)
523 * are saved and zeroed this means that if the BIOS tries to reference
524 * any data without explicitly loading the segment registers, the kernel
525 * will fault immediately rather than have some unforeseen circumstances
526 * for the rest of the kernel. And it will be very obvious! :-) Doing
527 * this depends on CS referring to the same physical memory as DS so that
528 * DS can be zeroed before the call. Unfortunately, we can't do anything
529 * about the stack segment/pointer. Also, we tell the compiler that
530 * everything could change.
532 * Also, we KNOW that for the non error case of apm_bios_call, there
533 * is no useful data returned in the low order 8 bits of eax.
536 static inline unsigned long __apm_irq_save(void)
539 local_save_flags(flags);
540 if (apm_info.allow_ints) {
541 if (irqs_disabled_flags(flags))
549 #define apm_irq_save(flags) \
550 do { flags = __apm_irq_save(); } while (0)
552 static inline void apm_irq_restore(unsigned long flags)
554 if (irqs_disabled_flags(flags))
556 else if (irqs_disabled())
561 # define APM_DECL_SEGS \
562 unsigned int saved_fs; unsigned int saved_gs;
563 # define APM_DO_SAVE_SEGS \
564 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
565 # define APM_DO_RESTORE_SEGS \
566 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
568 # define APM_DECL_SEGS
569 # define APM_DO_SAVE_SEGS
570 # define APM_DO_RESTORE_SEGS
574 * apm_bios_call - Make an APM BIOS 32bit call
575 * @func: APM function to execute
576 * @ebx_in: EBX register for call entry
577 * @ecx_in: ECX register for call entry
578 * @eax: EAX register return
579 * @ebx: EBX register return
580 * @ecx: ECX register return
581 * @edx: EDX register return
582 * @esi: ESI register return
584 * Make an APM call using the 32bit protected mode interface. The
585 * caller is responsible for knowing if APM BIOS is configured and
586 * enabled. This call can disable interrupts for a long period of
587 * time on some laptops. The return value is in AH and the carry
588 * flag is loaded into AL. If there is an error, then the error
589 * code is returned in AH (bits 8-15 of eax) and this function
593 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
594 u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
600 struct desc_struct save_desc_40;
601 struct desc_struct *gdt;
603 cpus = apm_save_cpus();
606 gdt = get_cpu_gdt_table(cpu);
607 save_desc_40 = gdt[0x40 / 8];
608 gdt[0x40 / 8] = bad_bios_desc;
612 apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
614 apm_irq_restore(flags);
615 gdt[0x40 / 8] = save_desc_40;
617 apm_restore_cpus(cpus);
623 * apm_bios_call_simple - make a simple APM BIOS 32bit call
624 * @func: APM function to invoke
625 * @ebx_in: EBX register value for BIOS call
626 * @ecx_in: ECX register value for BIOS call
627 * @eax: EAX register on return from the BIOS call
629 * Make a BIOS call that returns one value only, or just status.
630 * If there is an error, then the error code is returned in AH
631 * (bits 8-15 of eax) and this function returns non-zero. This is
632 * used for simpler BIOS operations. This call may hold interrupts
633 * off for a long time on some laptops.
636 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
643 struct desc_struct save_desc_40;
644 struct desc_struct *gdt;
646 cpus = apm_save_cpus();
649 gdt = get_cpu_gdt_table(cpu);
650 save_desc_40 = gdt[0x40 / 8];
651 gdt[0x40 / 8] = bad_bios_desc;
655 error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
657 apm_irq_restore(flags);
658 gdt[0x40 / 8] = save_desc_40;
660 apm_restore_cpus(cpus);
665 * apm_driver_version - APM driver version
666 * @val: loaded with the APM version on return
668 * Retrieve the APM version supported by the BIOS. This is only
669 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
672 * On entry val should point to a value indicating the APM driver
673 * version with the high byte being the major and the low byte the
674 * minor number both in BCD
676 * On return it will hold the BIOS revision supported in the
680 static int apm_driver_version(u_short *val)
684 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
685 return (eax >> 8) & 0xff;
691 * apm_get_event - get an APM event from the BIOS
692 * @event: pointer to the event
693 * @info: point to the event information
695 * The APM BIOS provides a polled information for event
696 * reporting. The BIOS expects to be polled at least every second
697 * when events are pending. When a message is found the caller should
698 * poll until no more messages are present. However, this causes
699 * problems on some laptops where a suspend event notification is
700 * not cleared until it is acknowledged.
702 * Additional information is returned in the info pointer, providing
703 * that APM 1.2 is in use. If no messges are pending the value 0x80
704 * is returned (No power management events pending).
707 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
714 if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
716 return (eax >> 8) & 0xff;
718 if (apm_info.connection_version < 0x0102)
719 *info = ~0; /* indicate info not valid */
726 * set_power_state - set the power management state
727 * @what: which items to transition
728 * @state: state to transition to
730 * Request an APM change of state for one or more system devices. The
731 * processor state must be transitioned last of all. what holds the
732 * class of device in the upper byte and the device number (0xFF for
733 * all) for the object to be transitioned.
735 * The state holds the state to transition to, which may in fact
736 * be an acceptance of a BIOS requested state change.
739 static int set_power_state(u_short what, u_short state)
743 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
744 return (eax >> 8) & 0xff;
749 * set_system_power_state - set system wide power state
750 * @state: which state to enter
752 * Transition the entire system into a new APM power state.
755 static int set_system_power_state(u_short state)
757 return set_power_state(APM_DEVICE_ALL, state);
761 * apm_do_idle - perform power saving
763 * This function notifies the BIOS that the processor is (in the view
764 * of the OS) idle. It returns -1 in the event that the BIOS refuses
765 * to handle the idle request. On a success the function returns 1
766 * if the BIOS did clock slowing or 0 otherwise.
769 static int apm_do_idle(void)
776 polling = !!(current_thread_info()->status & TS_POLLING);
778 current_thread_info()->status &= ~TS_POLLING;
780 * TS_POLLING-cleared state must be visible before we
785 if (!need_resched()) {
787 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
790 current_thread_info()->status |= TS_POLLING;
796 static unsigned long t;
798 /* This always fails on some SMP boards running UP kernels.
799 * Only report the failure the first 5 times.
803 printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
809 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
814 * apm_do_busy - inform the BIOS the CPU is busy
816 * Request that the BIOS brings the CPU back to full performance.
819 static void apm_do_busy(void)
823 if (clock_slowed || ALWAYS_CALL_BUSY) {
824 (void) apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
830 * If no process has really been interested in
831 * the CPU for some time, we want to call BIOS
832 * power management - we probably want
835 #define IDLE_CALC_LIMIT (HZ * 100)
836 #define IDLE_LEAKY_MAX 16
838 static void (*original_pm_idle)(void) __read_mostly;
841 * apm_cpu_idle - cpu idling for APM capable Linux
843 * This is the idling function the kernel executes when APM is available. It
844 * tries to do BIOS powermanagement based on the average system idle time.
845 * Furthermore it calls the system default idle routine.
848 static void apm_cpu_idle(void)
850 static int use_apm_idle; /* = 0 */
851 static unsigned int last_jiffies; /* = 0 */
852 static unsigned int last_stime; /* = 0 */
854 int apm_idle_done = 0;
855 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
859 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
861 last_jiffies = jiffies;
862 last_stime = current->stime;
863 } else if (jiffies_since_last_check > idle_period) {
864 unsigned int idle_percentage;
866 idle_percentage = current->stime - last_stime;
867 idle_percentage *= 100;
868 idle_percentage /= jiffies_since_last_check;
869 use_apm_idle = (idle_percentage > idle_threshold);
870 if (apm_info.forbid_idle)
872 last_jiffies = jiffies;
873 last_stime = current->stime;
876 bucket = IDLE_LEAKY_MAX;
878 while (!need_resched()) {
883 switch (apm_do_idle()) {
884 case 0: apm_idle_done = 1;
887 bucket = IDLE_LEAKY_MAX;
895 case 1: apm_idle_done = 1;
897 default: /* BIOS refused */
901 if (original_pm_idle)
905 jiffies_since_last_check = jiffies - last_jiffies;
906 if (jiffies_since_last_check > idle_period)
915 * apm_power_off - ask the BIOS to power off
917 * Handle the power off sequence. This is the one piece of code we
918 * will execute even on SMP machines. In order to deal with BIOS
919 * bugs we support real mode APM BIOS power off calls. We also make
920 * the SMP call on CPU0 as some systems will only honour this call
921 * on their first cpu.
924 static void apm_power_off(void)
926 unsigned char po_bios_call[] = {
927 0xb8, 0x00, 0x10, /* movw $0x1000,ax */
928 0x8e, 0xd0, /* movw ax,ss */
929 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */
930 0xb8, 0x07, 0x53, /* movw $0x5307,ax */
931 0xbb, 0x01, 0x00, /* movw $0x0001,bx */
932 0xb9, 0x03, 0x00, /* movw $0x0003,cx */
933 0xcd, 0x15 /* int $0x15 */
936 /* Some bioses don't like being called from CPU != 0 */
937 if (apm_info.realmode_power_off)
939 (void)apm_save_cpus();
940 machine_real_restart(po_bios_call, sizeof(po_bios_call));
943 (void) set_system_power_state(APM_STATE_OFF);
946 #ifdef CONFIG_APM_DO_ENABLE
949 * apm_enable_power_management - enable BIOS APM power management
950 * @enable: enable yes/no
952 * Enable or disable the APM BIOS power services.
955 static int apm_enable_power_management(int enable)
959 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
960 return APM_NOT_ENGAGED;
961 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
963 return (eax >> 8) & 0xff;
965 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
967 apm_info.bios.flags |= APM_BIOS_DISABLED;
973 * apm_get_power_status - get current power state
974 * @status: returned status
976 * @life: estimated life
978 * Obtain the current power status from the APM BIOS. We return a
979 * status which gives the rough battery status, and current power
980 * source. The bat value returned give an estimate as a percentage
981 * of life and a status value for the battery. The estimated life
982 * if reported is a lifetime in secodnds/minutes at current powwer
986 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
994 if (apm_info.get_power_status_broken)
995 return APM_32_UNSUPPORTED;
996 if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
997 &eax, &ebx, &ecx, &edx, &dummy))
998 return (eax >> 8) & 0xff;
1001 if (apm_info.get_power_status_swabinminutes) {
1002 *life = swab16((u16)edx);
1010 static int apm_get_battery_status(u_short which, u_short *status,
1011 u_short *bat, u_short *life, u_short *nbat)
1019 if (apm_info.connection_version < 0x0102) {
1020 /* pretend we only have one battery. */
1022 return APM_BAD_DEVICE;
1024 return apm_get_power_status(status, bat, life);
1027 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1028 &ebx, &ecx, &edx, &esi))
1029 return (eax >> 8) & 0xff;
1039 * apm_engage_power_management - enable PM on a device
1040 * @device: identity of device
1043 * Activate or deactive power management on either a specific device
1044 * or the entire system (%APM_DEVICE_ALL).
1047 static int apm_engage_power_management(u_short device, int enable)
1051 if ((enable == 0) && (device == APM_DEVICE_ALL)
1052 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1053 return APM_DISABLED;
1054 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1055 return (eax >> 8) & 0xff;
1056 if (device == APM_DEVICE_ALL) {
1058 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1060 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1065 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1068 * apm_console_blank - blank the display
1071 * Attempt to blank the console, firstly by blanking just video device
1072 * zero, and if that fails (some BIOSes don't support it) then it blanks
1073 * all video devices. Typically the BIOS will do laptop backlight and
1074 * monitor powerdown for us.
1077 static int apm_console_blank(int blank)
1079 int error = APM_NOT_ENGAGED; /* silence gcc */
1082 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1084 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1086 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1087 error = set_power_state(dev[i], state);
1089 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1092 if (error == APM_NOT_ENGAGED)
1096 if (error == APM_NOT_ENGAGED) {
1100 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1102 apm_error("set display", error);
1103 apm_error("engage interface", eng_error);
1106 return apm_console_blank(blank);
1109 apm_error("set display", error);
1114 static int queue_empty(struct apm_user *as)
1116 return as->event_head == as->event_tail;
1119 static apm_event_t get_queued_event(struct apm_user *as)
1121 if (++as->event_tail >= APM_MAX_EVENTS)
1123 return as->events[as->event_tail];
1126 static void queue_event(apm_event_t event, struct apm_user *sender)
1128 struct apm_user * as;
1130 spin_lock(&user_list_lock);
1131 if (user_list == NULL)
1133 for (as = user_list; as != NULL; as = as->next) {
1134 if ((as == sender) || (!as->reader))
1136 if (++as->event_head >= APM_MAX_EVENTS)
1139 if (as->event_head == as->event_tail) {
1140 static int notified;
1142 if (notified++ == 0)
1143 printk(KERN_ERR "apm: an event queue overflowed\n");
1144 if (++as->event_tail >= APM_MAX_EVENTS)
1147 as->events[as->event_head] = event;
1148 if ((!as->suser) || (!as->writer))
1151 case APM_SYS_SUSPEND:
1152 case APM_USER_SUSPEND:
1153 as->suspends_pending++;
1157 case APM_SYS_STANDBY:
1158 case APM_USER_STANDBY:
1159 as->standbys_pending++;
1164 wake_up_interruptible(&apm_waitqueue);
1166 spin_unlock(&user_list_lock);
1169 static void reinit_timer(void)
1171 #ifdef INIT_TIMER_AFTER_SUSPEND
1172 unsigned long flags;
1174 spin_lock_irqsave(&i8253_lock, flags);
1175 /* set the clock to HZ */
1176 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1178 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1180 outb(LATCH >> 8, PIT_CH0); /* MSB */
1182 spin_unlock_irqrestore(&i8253_lock, flags);
1186 static int suspend(int vetoable)
1189 struct apm_user *as;
1191 if (pm_send_all(PM_SUSPEND, (void *)3)) {
1194 if (apm_info.connection_version > 0x100)
1195 set_system_power_state(APM_STATE_REJECT);
1197 ignore_sys_suspend = 0;
1198 printk(KERN_WARNING "apm: suspend was vetoed.\n");
1201 printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
1204 device_suspend(PMSG_SUSPEND);
1205 local_irq_disable();
1206 device_power_down(PMSG_SUSPEND);
1210 save_processor_state();
1211 err = set_system_power_state(APM_STATE_SUSPEND);
1212 ignore_normal_resume = 1;
1213 restore_processor_state();
1215 local_irq_disable();
1218 if (err == APM_NO_ERROR)
1220 if (err != APM_SUCCESS)
1221 apm_error("suspend", err);
1222 err = (err == APM_SUCCESS) ? 0 : -EIO;
1226 pm_send_all(PM_RESUME, (void *)0);
1227 queue_event(APM_NORMAL_RESUME, NULL);
1229 spin_lock(&user_list_lock);
1230 for (as = user_list; as != NULL; as = as->next) {
1231 as->suspend_wait = 0;
1232 as->suspend_result = err;
1234 spin_unlock(&user_list_lock);
1235 wake_up_interruptible(&apm_suspend_waitqueue);
1239 static void standby(void)
1243 local_irq_disable();
1244 device_power_down(PMSG_SUSPEND);
1247 err = set_system_power_state(APM_STATE_STANDBY);
1248 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1249 apm_error("standby", err);
1251 local_irq_disable();
1256 static apm_event_t get_event(void)
1259 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1260 apm_eventinfo_t info;
1262 static int notified;
1264 /* we don't use the eventinfo */
1265 error = apm_get_event(&event, &info);
1266 if (error == APM_SUCCESS)
1269 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1270 apm_error("get_event", error);
1275 static void check_events(void)
1278 static unsigned long last_resume;
1279 static int ignore_bounce;
1281 while ((event = get_event()) != 0) {
1283 if (event <= NR_APM_EVENT_NAME)
1284 printk(KERN_DEBUG "apm: received %s notify\n",
1285 apm_event_name[event - 1]);
1287 printk(KERN_DEBUG "apm: received unknown "
1288 "event 0x%02x\n", event);
1291 && ((jiffies - last_resume) > bounce_interval))
1295 case APM_SYS_STANDBY:
1296 case APM_USER_STANDBY:
1297 queue_event(event, NULL);
1298 if (standbys_pending <= 0)
1302 case APM_USER_SUSPEND:
1303 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1304 if (apm_info.connection_version > 0x100)
1305 set_system_power_state(APM_STATE_REJECT);
1308 case APM_SYS_SUSPEND:
1309 if (ignore_bounce) {
1310 if (apm_info.connection_version > 0x100)
1311 set_system_power_state(APM_STATE_REJECT);
1315 * If we are already processing a SUSPEND,
1316 * then further SUSPEND events from the BIOS
1317 * will be ignored. We also return here to
1318 * cope with the fact that the Thinkpads keep
1319 * sending a SUSPEND event until something else
1322 if (ignore_sys_suspend)
1324 ignore_sys_suspend = 1;
1325 queue_event(event, NULL);
1326 if (suspends_pending <= 0)
1330 case APM_NORMAL_RESUME:
1331 case APM_CRITICAL_RESUME:
1332 case APM_STANDBY_RESUME:
1333 ignore_sys_suspend = 0;
1334 last_resume = jiffies;
1336 if ((event != APM_NORMAL_RESUME)
1337 || (ignore_normal_resume == 0)) {
1339 pm_send_all(PM_RESUME, (void *)0);
1340 queue_event(event, NULL);
1342 ignore_normal_resume = 0;
1345 case APM_CAPABILITY_CHANGE:
1346 case APM_LOW_BATTERY:
1347 case APM_POWER_STATUS_CHANGE:
1348 queue_event(event, NULL);
1349 /* If needed, notify drivers here */
1352 case APM_UPDATE_TIME:
1355 case APM_CRITICAL_SUSPEND:
1357 * We are not allowed to reject a critical suspend.
1365 static void apm_event_handler(void)
1367 static int pending_count = 4;
1370 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1371 if ((apm_info.connection_version > 0x100) &&
1372 (pending_count-- <= 0)) {
1375 printk(KERN_DEBUG "apm: setting state busy\n");
1376 err = set_system_power_state(APM_STATE_BUSY);
1378 apm_error("busy", err);
1386 * This is the APM thread main loop.
1389 static void apm_mainloop(void)
1391 DECLARE_WAITQUEUE(wait, current);
1393 add_wait_queue(&apm_waitqueue, &wait);
1394 set_current_state(TASK_INTERRUPTIBLE);
1396 schedule_timeout(APM_CHECK_TIMEOUT);
1397 if (kthread_should_stop())
1400 * Ok, check all events, check for idle (and mark us sleeping
1401 * so as not to count towards the load average)..
1403 set_current_state(TASK_INTERRUPTIBLE);
1404 apm_event_handler();
1406 remove_wait_queue(&apm_waitqueue, &wait);
1409 static int check_apm_user(struct apm_user *as, const char *func)
1411 if ((as == NULL) || (as->magic != APM_BIOS_MAGIC)) {
1412 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1418 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1420 struct apm_user * as;
1424 as = fp->private_data;
1425 if (check_apm_user(as, "read"))
1427 if ((int)count < sizeof(apm_event_t))
1429 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1431 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1433 while ((i >= sizeof(event)) && !queue_empty(as)) {
1434 event = get_queued_event(as);
1435 if (copy_to_user(buf, &event, sizeof(event))) {
1441 case APM_SYS_SUSPEND:
1442 case APM_USER_SUSPEND:
1443 as->suspends_read++;
1446 case APM_SYS_STANDBY:
1447 case APM_USER_STANDBY:
1448 as->standbys_read++;
1451 buf += sizeof(event);
1456 if (signal_pending(current))
1457 return -ERESTARTSYS;
1461 static unsigned int do_poll(struct file *fp, poll_table * wait)
1463 struct apm_user * as;
1465 as = fp->private_data;
1466 if (check_apm_user(as, "poll"))
1468 poll_wait(fp, &apm_waitqueue, wait);
1469 if (!queue_empty(as))
1470 return POLLIN | POLLRDNORM;
1474 static int do_ioctl(struct inode * inode, struct file *filp,
1475 u_int cmd, u_long arg)
1477 struct apm_user * as;
1479 as = filp->private_data;
1480 if (check_apm_user(as, "ioctl"))
1482 if ((!as->suser) || (!as->writer))
1485 case APM_IOC_STANDBY:
1486 if (as->standbys_read > 0) {
1487 as->standbys_read--;
1488 as->standbys_pending--;
1491 queue_event(APM_USER_STANDBY, as);
1492 if (standbys_pending <= 0)
1495 case APM_IOC_SUSPEND:
1496 if (as->suspends_read > 0) {
1497 as->suspends_read--;
1498 as->suspends_pending--;
1501 queue_event(APM_USER_SUSPEND, as);
1502 if (suspends_pending <= 0) {
1505 as->suspend_wait = 1;
1506 wait_event_interruptible(apm_suspend_waitqueue,
1507 as->suspend_wait == 0);
1508 return as->suspend_result;
1517 static int do_release(struct inode * inode, struct file * filp)
1519 struct apm_user * as;
1521 as = filp->private_data;
1522 if (check_apm_user(as, "release"))
1524 filp->private_data = NULL;
1525 if (as->standbys_pending > 0) {
1526 standbys_pending -= as->standbys_pending;
1527 if (standbys_pending <= 0)
1530 if (as->suspends_pending > 0) {
1531 suspends_pending -= as->suspends_pending;
1532 if (suspends_pending <= 0)
1535 spin_lock(&user_list_lock);
1536 if (user_list == as)
1537 user_list = as->next;
1539 struct apm_user * as1;
1541 for (as1 = user_list;
1542 (as1 != NULL) && (as1->next != as);
1546 printk(KERN_ERR "apm: filp not in user list\n");
1548 as1->next = as->next;
1550 spin_unlock(&user_list_lock);
1555 static int do_open(struct inode * inode, struct file * filp)
1557 struct apm_user * as;
1559 as = kmalloc(sizeof(*as), GFP_KERNEL);
1561 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1565 as->magic = APM_BIOS_MAGIC;
1566 as->event_tail = as->event_head = 0;
1567 as->suspends_pending = as->standbys_pending = 0;
1568 as->suspends_read = as->standbys_read = 0;
1570 * XXX - this is a tiny bit broken, when we consider BSD
1571 * process accounting. If the device is opened by root, we
1572 * instantly flag that we used superuser privs. Who knows,
1573 * we might close the device immediately without doing a
1574 * privileged operation -- cevans
1576 as->suser = capable(CAP_SYS_ADMIN);
1577 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1578 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1579 spin_lock(&user_list_lock);
1580 as->next = user_list;
1582 spin_unlock(&user_list_lock);
1583 filp->private_data = as;
1587 static int proc_apm_show(struct seq_file *m, void *v)
1593 unsigned short ac_line_status = 0xff;
1594 unsigned short battery_status = 0xff;
1595 unsigned short battery_flag = 0xff;
1596 int percentage = -1;
1597 int time_units = -1;
1600 if ((num_online_cpus() == 1) &&
1601 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1602 ac_line_status = (bx >> 8) & 0xff;
1603 battery_status = bx & 0xff;
1604 if ((cx & 0xff) != 0xff)
1605 percentage = cx & 0xff;
1607 if (apm_info.connection_version > 0x100) {
1608 battery_flag = (cx >> 8) & 0xff;
1610 units = (dx & 0x8000) ? "min" : "sec";
1611 time_units = dx & 0x7fff;
1615 /* Arguments, with symbols from linux/apm_bios.h. Information is
1616 from the Get Power Status (0x0a) call unless otherwise noted.
1618 0) Linux driver version (this will change if format changes)
1619 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1620 2) APM flags from APM Installation Check (0x00):
1621 bit 0: APM_16_BIT_SUPPORT
1622 bit 1: APM_32_BIT_SUPPORT
1623 bit 2: APM_IDLE_SLOWS_CLOCK
1624 bit 3: APM_BIOS_DISABLED
1625 bit 4: APM_BIOS_DISENGAGED
1629 0x02: On backup power (BIOS >= 1.1 only)
1636 0x04: Selected battery not present (BIOS >= 1.2 only)
1643 bit 7: No system battery
1645 6) Remaining battery life (percentage of charge):
1648 7) Remaining battery life (time units):
1649 Number of remaining minutes or seconds
1651 8) min = minutes; sec = seconds */
1653 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1655 (apm_info.bios.version >> 8) & 0xff,
1656 apm_info.bios.version & 0xff,
1657 apm_info.bios.flags,
1667 static int proc_apm_open(struct inode *inode, struct file *file)
1669 return single_open(file, proc_apm_show, NULL);
1672 static const struct file_operations apm_file_ops = {
1673 .owner = THIS_MODULE,
1674 .open = proc_apm_open,
1676 .llseek = seq_lseek,
1677 .release = single_release,
1680 static int apm(void *unused)
1691 * This is to avoid random crashes at boot time during initialization
1692 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1693 * Some bioses don't like being called from CPU != 0.
1694 * Method suggested by Ingo Molnar.
1696 set_cpus_allowed(current, cpumask_of_cpu(0));
1697 BUG_ON(smp_processor_id() != 0);
1700 if (apm_info.connection_version == 0) {
1701 apm_info.connection_version = apm_info.bios.version;
1702 if (apm_info.connection_version > 0x100) {
1704 * We only support BIOSs up to version 1.2
1706 if (apm_info.connection_version > 0x0102)
1707 apm_info.connection_version = 0x0102;
1708 error = apm_driver_version(&apm_info.connection_version);
1709 if (error != APM_SUCCESS) {
1710 apm_error("driver version", error);
1711 /* Fall back to an APM 1.0 connection. */
1712 apm_info.connection_version = 0x100;
1718 printk(KERN_INFO "apm: Connection version %d.%d\n",
1719 (apm_info.connection_version >> 8) & 0xff,
1720 apm_info.connection_version & 0xff);
1722 #ifdef CONFIG_APM_DO_ENABLE
1723 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1725 * This call causes my NEC UltraLite Versa 33/C to hang if it
1726 * is booted with PM disabled but not in the docking station.
1729 error = apm_enable_power_management(1);
1731 apm_error("enable power management", error);
1737 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1738 && (apm_info.connection_version > 0x0100)) {
1739 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1741 apm_error("engage power management", error);
1746 if (debug && (num_online_cpus() == 1 || smp )) {
1747 error = apm_get_power_status(&bx, &cx, &dx);
1749 printk(KERN_INFO "apm: power status not available\n");
1751 switch ((bx >> 8) & 0xff) {
1752 case 0: power_stat = "off line"; break;
1753 case 1: power_stat = "on line"; break;
1754 case 2: power_stat = "on backup power"; break;
1755 default: power_stat = "unknown"; break;
1757 switch (bx & 0xff) {
1758 case 0: bat_stat = "high"; break;
1759 case 1: bat_stat = "low"; break;
1760 case 2: bat_stat = "critical"; break;
1761 case 3: bat_stat = "charging"; break;
1762 default: bat_stat = "unknown"; break;
1765 "apm: AC %s, battery status %s, battery life ",
1766 power_stat, bat_stat);
1767 if ((cx & 0xff) == 0xff)
1768 printk("unknown\n");
1770 printk("%d%%\n", cx & 0xff);
1771 if (apm_info.connection_version > 0x100) {
1773 "apm: battery flag 0x%02x, battery life ",
1776 printk("unknown\n");
1778 printk("%d %s\n", dx & 0x7fff,
1780 "minutes" : "seconds");
1785 /* Install our power off handler.. */
1787 pm_power_off = apm_power_off;
1789 if (num_online_cpus() == 1 || smp) {
1790 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1791 console_blank_hook = apm_console_blank;
1794 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1795 console_blank_hook = NULL;
1803 static int __init apm_setup(char *str)
1807 while ((str != NULL) && (*str != '\0')) {
1808 if (strncmp(str, "off", 3) == 0)
1810 if (strncmp(str, "on", 2) == 0)
1812 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1813 (strncmp(str, "bounce_interval=", 16) == 0))
1814 bounce_interval = simple_strtol(str + 16, NULL, 0);
1815 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1816 (strncmp(str, "idle_threshold=", 15) == 0))
1817 idle_threshold = simple_strtol(str + 15, NULL, 0);
1818 if ((strncmp(str, "idle-period=", 12) == 0) ||
1819 (strncmp(str, "idle_period=", 12) == 0))
1820 idle_period = simple_strtol(str + 12, NULL, 0);
1821 invert = (strncmp(str, "no-", 3) == 0) ||
1822 (strncmp(str, "no_", 3) == 0);
1825 if (strncmp(str, "debug", 5) == 0)
1827 if ((strncmp(str, "power-off", 9) == 0) ||
1828 (strncmp(str, "power_off", 9) == 0))
1829 power_off = !invert;
1830 if (strncmp(str, "smp", 3) == 0)
1833 idle_threshold = 100;
1835 if ((strncmp(str, "allow-ints", 10) == 0) ||
1836 (strncmp(str, "allow_ints", 10) == 0))
1837 apm_info.allow_ints = !invert;
1838 if ((strncmp(str, "broken-psr", 10) == 0) ||
1839 (strncmp(str, "broken_psr", 10) == 0))
1840 apm_info.get_power_status_broken = !invert;
1841 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1842 (strncmp(str, "realmode_power_off", 18) == 0))
1843 apm_info.realmode_power_off = !invert;
1844 str = strchr(str, ',');
1846 str += strspn(str, ", \t");
1851 __setup("apm=", apm_setup);
1854 static const struct file_operations apm_bios_fops = {
1855 .owner = THIS_MODULE,
1860 .release = do_release,
1863 static struct miscdevice apm_device = {
1870 /* Simple "print if true" callback */
1871 static int __init print_if_true(struct dmi_system_id *d)
1873 printk("%s\n", d->ident);
1878 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1879 * disabled before the suspend. Linux used to get terribly confused by that.
1881 static int __init broken_ps2_resume(struct dmi_system_id *d)
1883 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug workaround hopefully not needed.\n", d->ident);
1887 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1888 static int __init set_realmode_power_off(struct dmi_system_id *d)
1890 if (apm_info.realmode_power_off == 0) {
1891 apm_info.realmode_power_off = 1;
1892 printk(KERN_INFO "%s bios detected. Using realmode poweroff only.\n", d->ident);
1897 /* Some laptops require interrupts to be enabled during APM calls */
1898 static int __init set_apm_ints(struct dmi_system_id *d)
1900 if (apm_info.allow_ints == 0) {
1901 apm_info.allow_ints = 1;
1902 printk(KERN_INFO "%s machine detected. Enabling interrupts during APM calls.\n", d->ident);
1907 /* Some APM bioses corrupt memory or just plain do not work */
1908 static int __init apm_is_horked(struct dmi_system_id *d)
1910 if (apm_info.disabled == 0) {
1911 apm_info.disabled = 1;
1912 printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
1917 static int __init apm_is_horked_d850md(struct dmi_system_id *d)
1919 if (apm_info.disabled == 0) {
1920 apm_info.disabled = 1;
1921 printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
1922 printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
1923 printk(KERN_INFO "download from support.intel.com \n");
1928 /* Some APM bioses hang on APM idle calls */
1929 static int __init apm_likes_to_melt(struct dmi_system_id *d)
1931 if (apm_info.forbid_idle == 0) {
1932 apm_info.forbid_idle = 1;
1933 printk(KERN_INFO "%s machine detected. Disabling APM idle calls.\n", d->ident);
1939 * Check for clue free BIOS implementations who use
1940 * the following QA technique
1942 * [ Write BIOS Code ]<------
1944 * < Does it Compile >----N--
1946 * < Does it Boot Win98 >-N--
1950 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
1951 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
1953 static int __init broken_apm_power(struct dmi_system_id *d)
1955 apm_info.get_power_status_broken = 1;
1956 printk(KERN_WARNING "BIOS strings suggest APM bugs, disabling power status reporting.\n");
1961 * This bios swaps the APM minute reporting bytes over (Many sony laptops
1962 * have this problem).
1964 static int __init swab_apm_power_in_minutes(struct dmi_system_id *d)
1966 apm_info.get_power_status_swabinminutes = 1;
1967 printk(KERN_WARNING "BIOS strings suggest APM reports battery life in minutes and wrong byte order.\n");
1971 static struct dmi_system_id __initdata apm_dmi_table[] = {
1974 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
1975 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
1976 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
1978 { /* Handle problems with APM on the C600 */
1979 broken_ps2_resume, "Dell Latitude C600",
1980 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
1981 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
1983 { /* Allow interrupts during suspend on Dell Latitude laptops*/
1984 set_apm_ints, "Dell Latitude",
1985 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
1986 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
1989 apm_is_horked, "Dell Inspiron 2500",
1990 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
1991 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
1992 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
1993 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
1995 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
1996 set_apm_ints, "Dell Inspiron", {
1997 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
1998 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2000 { /* Handle problems with APM on Inspiron 5000e */
2001 broken_apm_power, "Dell Inspiron 5000e",
2002 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2003 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2004 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2006 { /* Handle problems with APM on Inspiron 2500 */
2007 broken_apm_power, "Dell Inspiron 2500",
2008 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2009 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2010 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2013 apm_is_horked, "Dell Dimension 4100",
2014 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2015 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2016 DMI_MATCH(DMI_BIOS_VENDOR,"Intel Corp."),
2017 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2019 { /* Allow interrupts during suspend on Compaq Laptops*/
2020 set_apm_ints, "Compaq 12XL125",
2021 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2022 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2023 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2024 DMI_MATCH(DMI_BIOS_VERSION,"4.06"), },
2026 { /* Allow interrupts during APM or the clock goes slow */
2027 set_apm_ints, "ASUSTeK",
2028 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2029 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2031 { /* APM blows on shutdown */
2032 apm_is_horked, "ABIT KX7-333[R]",
2033 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2034 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2037 apm_is_horked, "Trigem Delhi3",
2038 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2039 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2042 apm_is_horked, "Fujitsu-Siemens",
2043 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2044 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2047 apm_is_horked_d850md, "Intel D850MD",
2048 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2049 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2052 apm_is_horked, "Intel D810EMO",
2053 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2054 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2057 apm_is_horked, "Dell XPS-Z",
2058 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2059 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2060 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2063 apm_is_horked, "Sharp PC-PJ/AX",
2064 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2065 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2066 DMI_MATCH(DMI_BIOS_VENDOR,"SystemSoft"),
2067 DMI_MATCH(DMI_BIOS_VERSION,"Version R2.08"), },
2070 apm_is_horked, "Dell Inspiron 2500",
2071 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2072 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2073 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
2074 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2076 { /* APM idle hangs */
2077 apm_likes_to_melt, "Jabil AMD",
2078 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2079 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2081 { /* APM idle hangs */
2082 apm_likes_to_melt, "AMI Bios",
2083 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2084 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2086 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2087 swab_apm_power_in_minutes, "Sony VAIO",
2088 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2089 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2090 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2092 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2093 swab_apm_power_in_minutes, "Sony VAIO",
2094 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2095 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2096 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2098 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2099 swab_apm_power_in_minutes, "Sony VAIO",
2100 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2101 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2102 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2104 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2105 swab_apm_power_in_minutes, "Sony VAIO",
2106 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2107 DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2108 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2110 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2111 swab_apm_power_in_minutes, "Sony VAIO",
2112 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2113 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2114 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2116 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2117 swab_apm_power_in_minutes, "Sony VAIO",
2118 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2119 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2120 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2122 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2123 swab_apm_power_in_minutes, "Sony VAIO",
2124 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2125 DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2126 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2128 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2129 swab_apm_power_in_minutes, "Sony VAIO",
2130 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2131 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2132 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2134 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2135 swab_apm_power_in_minutes, "Sony VAIO",
2136 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2137 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2138 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2140 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2141 swab_apm_power_in_minutes, "Sony VAIO",
2142 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2143 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2144 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2147 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2148 swab_apm_power_in_minutes, "Sony VAIO",
2149 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2150 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2151 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2153 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2154 swab_apm_power_in_minutes, "Sony VAIO",
2155 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2156 DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2157 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2159 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2160 swab_apm_power_in_minutes, "Sony VAIO",
2161 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2163 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2165 { /* broken PM poweroff bios */
2166 set_realmode_power_off, "Award Software v4.60 PGMA",
2167 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2168 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2169 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2172 /* Generic per vendor APM settings */
2174 { /* Allow interrupts during suspend on IBM laptops */
2175 set_apm_ints, "IBM",
2176 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2183 * Just start the APM thread. We do NOT want to do APM BIOS
2184 * calls from anything but the APM thread, if for no other reason
2185 * than the fact that we don't trust the APM BIOS. This way,
2186 * most common APM BIOS problems that lead to protection errors
2187 * etc will have at least some level of being contained...
2189 * In short, if something bad happens, at least we have a choice
2190 * of just killing the apm thread..
2192 static int __init apm_init(void)
2194 struct proc_dir_entry *apm_proc;
2195 struct desc_struct *gdt;
2198 dmi_check_system(apm_dmi_table);
2200 if (apm_info.bios.version == 0 || paravirt_enabled()) {
2201 printk(KERN_INFO "apm: BIOS not found.\n");
2205 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2206 ((apm_info.bios.version >> 8) & 0xff),
2207 (apm_info.bios.version & 0xff),
2208 apm_info.bios.flags,
2210 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2211 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2216 apm_info.allow_ints = 1;
2218 apm_info.get_power_status_broken = 1;
2219 if (realmode_power_off)
2220 apm_info.realmode_power_off = 1;
2221 /* User can override, but default is to trust DMI */
2222 if (apm_disabled != -1)
2223 apm_info.disabled = apm_disabled;
2226 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2227 * but is reportedly a 1.0 BIOS.
2229 if (apm_info.bios.version == 0x001)
2230 apm_info.bios.version = 0x100;
2232 /* BIOS < 1.2 doesn't set cseg_16_len */
2233 if (apm_info.bios.version < 0x102)
2234 apm_info.bios.cseg_16_len = 0; /* 64k */
2237 printk(KERN_INFO "apm: entry %x:%lx cseg16 %x dseg %x",
2238 apm_info.bios.cseg, apm_info.bios.offset,
2239 apm_info.bios.cseg_16, apm_info.bios.dseg);
2240 if (apm_info.bios.version > 0x100)
2241 printk(" cseg len %x, dseg len %x",
2242 apm_info.bios.cseg_len,
2243 apm_info.bios.dseg_len);
2244 if (apm_info.bios.version > 0x101)
2245 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2249 if (apm_info.disabled) {
2250 printk(KERN_NOTICE "apm: disabled on user request.\n");
2253 if ((num_online_cpus() > 1) && !power_off && !smp) {
2254 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2255 apm_info.disabled = 1;
2258 if (PM_IS_ACTIVE()) {
2259 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2260 apm_info.disabled = 1;
2263 #ifdef CONFIG_PM_LEGACY
2268 * Set up a segment that references the real mode segment 0x40
2269 * that extends up to the end of page zero (that we have reserved).
2270 * This is for buggy BIOS's that refer to (real mode) segment 0x40
2271 * even though they are called in protected mode.
2273 set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2274 _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2277 * Set up the long jump entry point to the APM BIOS, which is called
2278 * from inline assembly.
2280 apm_bios_entry.offset = apm_info.bios.offset;
2281 apm_bios_entry.segment = APM_CS;
2284 * The APM 1.1 BIOS is supposed to provide limit information that it
2285 * recognizes. Many machines do this correctly, but many others do
2286 * not restrict themselves to their claimed limit. When this happens,
2287 * they will cause a segmentation violation in the kernel at boot time.
2288 * Most BIOS's, however, will respect a 64k limit, so we use that.
2290 * Note we only set APM segments on CPU zero, since we pin the APM
2293 gdt = get_cpu_gdt_table(0);
2294 set_base(gdt[APM_CS >> 3],
2295 __va((unsigned long)apm_info.bios.cseg << 4));
2296 set_base(gdt[APM_CS_16 >> 3],
2297 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2298 set_base(gdt[APM_DS >> 3],
2299 __va((unsigned long)apm_info.bios.dseg << 4));
2301 apm_proc = create_proc_entry("apm", 0, NULL);
2303 apm_proc->proc_fops = &apm_file_ops;
2305 kapmd_task = kthread_create(apm, NULL, "kapmd");
2306 if (IS_ERR(kapmd_task)) {
2307 printk(KERN_ERR "apm: disabled - Unable to start kernel "
2309 err = PTR_ERR(kapmd_task);
2311 remove_proc_entry("apm", NULL);
2314 kapmd_task->flags |= PF_NOFREEZE;
2315 wake_up_process(kapmd_task);
2317 if (num_online_cpus() > 1 && !smp ) {
2319 "apm: disabled - APM is not SMP safe (power off active).\n");
2324 * Note we don't actually care if the misc_device cannot be registered.
2325 * this driver can do its job without it, even if userspace can't
2326 * control it. just log the error
2328 if (misc_register(&apm_device))
2329 printk(KERN_WARNING "apm: Could not register misc device.\n");
2332 idle_period = (idle_period * HZ) / 100;
2333 if (idle_threshold < 100) {
2334 original_pm_idle = pm_idle;
2335 pm_idle = apm_cpu_idle;
2342 static void __exit apm_exit(void)
2347 pm_idle = original_pm_idle;
2349 * We are about to unload the current idle thread pm callback
2350 * (pm_idle), Wait for all processors to update cached/local
2351 * copies of pm_idle before proceeding.
2355 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2356 && (apm_info.connection_version > 0x0100)) {
2357 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2359 apm_error("disengage power management", error);
2361 misc_deregister(&apm_device);
2362 remove_proc_entry("apm", NULL);
2364 pm_power_off = NULL;
2366 kthread_stop(kapmd_task);
2369 #ifdef CONFIG_PM_LEGACY
2374 module_init(apm_init);
2375 module_exit(apm_exit);
2377 MODULE_AUTHOR("Stephen Rothwell");
2378 MODULE_DESCRIPTION("Advanced Power Management");
2379 MODULE_LICENSE("GPL");
2380 module_param(debug, bool, 0644);
2381 MODULE_PARM_DESC(debug, "Enable debug mode");
2382 module_param(power_off, bool, 0444);
2383 MODULE_PARM_DESC(power_off, "Enable power off");
2384 module_param(bounce_interval, int, 0444);
2385 MODULE_PARM_DESC(bounce_interval,
2386 "Set the number of ticks to ignore suspend bounces");
2387 module_param(allow_ints, bool, 0444);
2388 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2389 module_param(broken_psr, bool, 0444);
2390 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2391 module_param(realmode_power_off, bool, 0444);
2392 MODULE_PARM_DESC(realmode_power_off,
2393 "Switch to real mode before powering off");
2394 module_param(idle_threshold, int, 0444);
2395 MODULE_PARM_DESC(idle_threshold,
2396 "System idle percentage above which to make APM BIOS idle calls");
2397 module_param(idle_period, int, 0444);
2398 MODULE_PARM_DESC(idle_period,
2399 "Period (in sec/100) over which to caculate the idle percentage");
2400 module_param(smp, bool, 0444);
2401 MODULE_PARM_DESC(smp,
2402 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2403 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);