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@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/freezer.h>
226 #include <linux/smp.h>
227 #include <linux/dmi.h>
228 #include <linux/suspend.h>
229 #include <linux/kthread.h>
231 #include <asm/system.h>
232 #include <asm/uaccess.h>
233 #include <asm/desc.h>
234 #include <asm/i8253.h>
235 #include <asm/paravirt.h>
236 #include <asm/reboot.h>
238 #include "io_ports.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 #ifdef CONFIG_APM_REAL_MODE_POWER_OFF
395 static int realmode_power_off = 1;
397 static int realmode_power_off;
399 #ifdef CONFIG_APM_ALLOW_INTS
400 static int allow_ints = 1;
402 static int allow_ints;
404 static int broken_psr;
406 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
407 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
408 static struct apm_user * user_list;
409 static DEFINE_SPINLOCK(user_list_lock);
410 static const struct desc_struct bad_bios_desc = { 0, 0x00409200 };
412 static const char driver_version[] = "1.16ac"; /* no spaces */
414 static struct task_struct *kapmd_task;
417 * APM event names taken from the APM 1.2 specification. These are
418 * the message codes that the BIOS uses to tell us about events
420 static const char * const apm_event_name[] = {
426 "power status change",
431 "system standby resume",
432 "capabilities change"
434 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
436 typedef struct lookup_t {
442 * The BIOS returns a set of standard error codes in AX when the
446 static const lookup_t error_table[] = {
447 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
448 { APM_DISABLED, "Power management disabled" },
449 { APM_CONNECTED, "Real mode interface already connected" },
450 { APM_NOT_CONNECTED, "Interface not connected" },
451 { APM_16_CONNECTED, "16 bit interface already connected" },
452 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
453 { APM_32_CONNECTED, "32 bit interface already connected" },
454 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
455 { APM_BAD_DEVICE, "Unrecognized device ID" },
456 { APM_BAD_PARAM, "Parameter out of range" },
457 { APM_NOT_ENGAGED, "Interface not engaged" },
458 { APM_BAD_FUNCTION, "Function not supported" },
459 { APM_RESUME_DISABLED, "Resume timer disabled" },
460 { APM_BAD_STATE, "Unable to enter requested state" },
461 /* N/A { APM_NO_EVENTS, "No events pending" }, */
462 { APM_NO_ERROR, "BIOS did not set a return code" },
463 { APM_NOT_PRESENT, "No APM present" }
465 #define ERROR_COUNT ARRAY_SIZE(error_table)
468 * apm_error - display an APM error
469 * @str: information string
470 * @err: APM BIOS return code
472 * Write a meaningful log entry to the kernel log in the event of
476 static void apm_error(char *str, int err)
480 for (i = 0; i < ERROR_COUNT; i++)
481 if (error_table[i].key == err) break;
483 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
485 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
490 * Lock APM functionality to physical CPU 0
495 static cpumask_t apm_save_cpus(void)
497 cpumask_t x = current->cpus_allowed;
498 /* Some bioses don't like being called from CPU != 0 */
499 set_cpus_allowed(current, cpumask_of_cpu(0));
500 BUG_ON(smp_processor_id() != 0);
504 static inline void apm_restore_cpus(cpumask_t mask)
506 set_cpus_allowed(current, mask);
512 * No CPU lockdown needed on a uniprocessor
515 #define apm_save_cpus() (current->cpus_allowed)
516 #define apm_restore_cpus(x) (void)(x)
521 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
522 * apm_info.allow_ints, we are being really paranoid here! Not only
523 * are interrupts disabled, but all the segment registers (except SS)
524 * are saved and zeroed this means that if the BIOS tries to reference
525 * any data without explicitly loading the segment registers, the kernel
526 * will fault immediately rather than have some unforeseen circumstances
527 * for the rest of the kernel. And it will be very obvious! :-) Doing
528 * this depends on CS referring to the same physical memory as DS so that
529 * DS can be zeroed before the call. Unfortunately, we can't do anything
530 * about the stack segment/pointer. Also, we tell the compiler that
531 * everything could change.
533 * Also, we KNOW that for the non error case of apm_bios_call, there
534 * is no useful data returned in the low order 8 bits of eax.
537 static inline unsigned long __apm_irq_save(void)
540 local_save_flags(flags);
541 if (apm_info.allow_ints) {
542 if (irqs_disabled_flags(flags))
550 #define apm_irq_save(flags) \
551 do { flags = __apm_irq_save(); } while (0)
553 static inline void apm_irq_restore(unsigned long flags)
555 if (irqs_disabled_flags(flags))
557 else if (irqs_disabled())
562 # define APM_DECL_SEGS \
563 unsigned int saved_fs; unsigned int saved_gs;
564 # define APM_DO_SAVE_SEGS \
565 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
566 # define APM_DO_RESTORE_SEGS \
567 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
569 # define APM_DECL_SEGS
570 # define APM_DO_SAVE_SEGS
571 # define APM_DO_RESTORE_SEGS
575 * apm_bios_call - Make an APM BIOS 32bit call
576 * @func: APM function to execute
577 * @ebx_in: EBX register for call entry
578 * @ecx_in: ECX register for call entry
579 * @eax: EAX register return
580 * @ebx: EBX register return
581 * @ecx: ECX register return
582 * @edx: EDX register return
583 * @esi: ESI register return
585 * Make an APM call using the 32bit protected mode interface. The
586 * caller is responsible for knowing if APM BIOS is configured and
587 * enabled. This call can disable interrupts for a long period of
588 * time on some laptops. The return value is in AH and the carry
589 * flag is loaded into AL. If there is an error, then the error
590 * code is returned in AH (bits 8-15 of eax) and this function
594 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
595 u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
601 struct desc_struct save_desc_40;
602 struct desc_struct *gdt;
604 cpus = apm_save_cpus();
607 gdt = get_cpu_gdt_table(cpu);
608 save_desc_40 = gdt[0x40 / 8];
609 gdt[0x40 / 8] = bad_bios_desc;
613 apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
615 apm_irq_restore(flags);
616 gdt[0x40 / 8] = save_desc_40;
618 apm_restore_cpus(cpus);
624 * apm_bios_call_simple - make a simple APM BIOS 32bit call
625 * @func: APM function to invoke
626 * @ebx_in: EBX register value for BIOS call
627 * @ecx_in: ECX register value for BIOS call
628 * @eax: EAX register on return from the BIOS call
630 * Make a BIOS call that returns one value only, or just status.
631 * If there is an error, then the error code is returned in AH
632 * (bits 8-15 of eax) and this function returns non-zero. This is
633 * used for simpler BIOS operations. This call may hold interrupts
634 * off for a long time on some laptops.
637 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
644 struct desc_struct save_desc_40;
645 struct desc_struct *gdt;
647 cpus = apm_save_cpus();
650 gdt = get_cpu_gdt_table(cpu);
651 save_desc_40 = gdt[0x40 / 8];
652 gdt[0x40 / 8] = bad_bios_desc;
656 error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
658 apm_irq_restore(flags);
659 gdt[0x40 / 8] = save_desc_40;
661 apm_restore_cpus(cpus);
666 * apm_driver_version - APM driver version
667 * @val: loaded with the APM version on return
669 * Retrieve the APM version supported by the BIOS. This is only
670 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
673 * On entry val should point to a value indicating the APM driver
674 * version with the high byte being the major and the low byte the
675 * minor number both in BCD
677 * On return it will hold the BIOS revision supported in the
681 static int apm_driver_version(u_short *val)
685 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
686 return (eax >> 8) & 0xff;
692 * apm_get_event - get an APM event from the BIOS
693 * @event: pointer to the event
694 * @info: point to the event information
696 * The APM BIOS provides a polled information for event
697 * reporting. The BIOS expects to be polled at least every second
698 * when events are pending. When a message is found the caller should
699 * poll until no more messages are present. However, this causes
700 * problems on some laptops where a suspend event notification is
701 * not cleared until it is acknowledged.
703 * Additional information is returned in the info pointer, providing
704 * that APM 1.2 is in use. If no messges are pending the value 0x80
705 * is returned (No power management events pending).
708 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
715 if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
717 return (eax >> 8) & 0xff;
719 if (apm_info.connection_version < 0x0102)
720 *info = ~0; /* indicate info not valid */
727 * set_power_state - set the power management state
728 * @what: which items to transition
729 * @state: state to transition to
731 * Request an APM change of state for one or more system devices. The
732 * processor state must be transitioned last of all. what holds the
733 * class of device in the upper byte and the device number (0xFF for
734 * all) for the object to be transitioned.
736 * The state holds the state to transition to, which may in fact
737 * be an acceptance of a BIOS requested state change.
740 static int set_power_state(u_short what, u_short state)
744 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
745 return (eax >> 8) & 0xff;
750 * set_system_power_state - set system wide power state
751 * @state: which state to enter
753 * Transition the entire system into a new APM power state.
756 static int set_system_power_state(u_short state)
758 return set_power_state(APM_DEVICE_ALL, state);
762 * apm_do_idle - perform power saving
764 * This function notifies the BIOS that the processor is (in the view
765 * of the OS) idle. It returns -1 in the event that the BIOS refuses
766 * to handle the idle request. On a success the function returns 1
767 * if the BIOS did clock slowing or 0 otherwise.
770 static int apm_do_idle(void)
777 polling = !!(current_thread_info()->status & TS_POLLING);
779 current_thread_info()->status &= ~TS_POLLING;
781 * TS_POLLING-cleared state must be visible before we
786 if (!need_resched()) {
788 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
791 current_thread_info()->status |= TS_POLLING;
797 static unsigned long t;
799 /* This always fails on some SMP boards running UP kernels.
800 * Only report the failure the first 5 times.
804 printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
810 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
815 * apm_do_busy - inform the BIOS the CPU is busy
817 * Request that the BIOS brings the CPU back to full performance.
820 static void apm_do_busy(void)
824 if (clock_slowed || ALWAYS_CALL_BUSY) {
825 (void) apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
831 * If no process has really been interested in
832 * the CPU for some time, we want to call BIOS
833 * power management - we probably want
836 #define IDLE_CALC_LIMIT (HZ * 100)
837 #define IDLE_LEAKY_MAX 16
839 static void (*original_pm_idle)(void) __read_mostly;
842 * apm_cpu_idle - cpu idling for APM capable Linux
844 * This is the idling function the kernel executes when APM is available. It
845 * tries to do BIOS powermanagement based on the average system idle time.
846 * Furthermore it calls the system default idle routine.
849 static void apm_cpu_idle(void)
851 static int use_apm_idle; /* = 0 */
852 static unsigned int last_jiffies; /* = 0 */
853 static unsigned int last_stime; /* = 0 */
855 int apm_idle_done = 0;
856 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
860 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
862 last_jiffies = jiffies;
863 last_stime = current->stime;
864 } else if (jiffies_since_last_check > idle_period) {
865 unsigned int idle_percentage;
867 idle_percentage = current->stime - last_stime;
868 idle_percentage *= 100;
869 idle_percentage /= jiffies_since_last_check;
870 use_apm_idle = (idle_percentage > idle_threshold);
871 if (apm_info.forbid_idle)
873 last_jiffies = jiffies;
874 last_stime = current->stime;
877 bucket = IDLE_LEAKY_MAX;
879 while (!need_resched()) {
884 switch (apm_do_idle()) {
885 case 0: apm_idle_done = 1;
888 bucket = IDLE_LEAKY_MAX;
896 case 1: apm_idle_done = 1;
898 default: /* BIOS refused */
902 if (original_pm_idle)
906 jiffies_since_last_check = jiffies - last_jiffies;
907 if (jiffies_since_last_check > idle_period)
916 * apm_power_off - ask the BIOS to power off
918 * Handle the power off sequence. This is the one piece of code we
919 * will execute even on SMP machines. In order to deal with BIOS
920 * bugs we support real mode APM BIOS power off calls. We also make
921 * the SMP call on CPU0 as some systems will only honour this call
922 * on their first cpu.
925 static void apm_power_off(void)
927 unsigned char po_bios_call[] = {
928 0xb8, 0x00, 0x10, /* movw $0x1000,ax */
929 0x8e, 0xd0, /* movw ax,ss */
930 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */
931 0xb8, 0x07, 0x53, /* movw $0x5307,ax */
932 0xbb, 0x01, 0x00, /* movw $0x0001,bx */
933 0xb9, 0x03, 0x00, /* movw $0x0003,cx */
934 0xcd, 0x15 /* int $0x15 */
937 /* Some bioses don't like being called from CPU != 0 */
938 if (apm_info.realmode_power_off)
940 (void)apm_save_cpus();
941 machine_real_restart(po_bios_call, sizeof(po_bios_call));
944 (void) set_system_power_state(APM_STATE_OFF);
947 #ifdef CONFIG_APM_DO_ENABLE
950 * apm_enable_power_management - enable BIOS APM power management
951 * @enable: enable yes/no
953 * Enable or disable the APM BIOS power services.
956 static int apm_enable_power_management(int enable)
960 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
961 return APM_NOT_ENGAGED;
962 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
964 return (eax >> 8) & 0xff;
966 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
968 apm_info.bios.flags |= APM_BIOS_DISABLED;
974 * apm_get_power_status - get current power state
975 * @status: returned status
977 * @life: estimated life
979 * Obtain the current power status from the APM BIOS. We return a
980 * status which gives the rough battery status, and current power
981 * source. The bat value returned give an estimate as a percentage
982 * of life and a status value for the battery. The estimated life
983 * if reported is a lifetime in secodnds/minutes at current powwer
987 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
995 if (apm_info.get_power_status_broken)
996 return APM_32_UNSUPPORTED;
997 if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
998 &eax, &ebx, &ecx, &edx, &dummy))
999 return (eax >> 8) & 0xff;
1002 if (apm_info.get_power_status_swabinminutes) {
1003 *life = swab16((u16)edx);
1011 static int apm_get_battery_status(u_short which, u_short *status,
1012 u_short *bat, u_short *life, u_short *nbat)
1020 if (apm_info.connection_version < 0x0102) {
1021 /* pretend we only have one battery. */
1023 return APM_BAD_DEVICE;
1025 return apm_get_power_status(status, bat, life);
1028 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1029 &ebx, &ecx, &edx, &esi))
1030 return (eax >> 8) & 0xff;
1040 * apm_engage_power_management - enable PM on a device
1041 * @device: identity of device
1044 * Activate or deactive power management on either a specific device
1045 * or the entire system (%APM_DEVICE_ALL).
1048 static int apm_engage_power_management(u_short device, int enable)
1052 if ((enable == 0) && (device == APM_DEVICE_ALL)
1053 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1054 return APM_DISABLED;
1055 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1056 return (eax >> 8) & 0xff;
1057 if (device == APM_DEVICE_ALL) {
1059 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1061 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1066 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1069 * apm_console_blank - blank the display
1072 * Attempt to blank the console, firstly by blanking just video device
1073 * zero, and if that fails (some BIOSes don't support it) then it blanks
1074 * all video devices. Typically the BIOS will do laptop backlight and
1075 * monitor powerdown for us.
1078 static int apm_console_blank(int blank)
1080 int error = APM_NOT_ENGAGED; /* silence gcc */
1083 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1085 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1087 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1088 error = set_power_state(dev[i], state);
1090 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1093 if (error == APM_NOT_ENGAGED)
1097 if (error == APM_NOT_ENGAGED) {
1101 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1103 apm_error("set display", error);
1104 apm_error("engage interface", eng_error);
1107 return apm_console_blank(blank);
1110 apm_error("set display", error);
1115 static int queue_empty(struct apm_user *as)
1117 return as->event_head == as->event_tail;
1120 static apm_event_t get_queued_event(struct apm_user *as)
1122 if (++as->event_tail >= APM_MAX_EVENTS)
1124 return as->events[as->event_tail];
1127 static void queue_event(apm_event_t event, struct apm_user *sender)
1129 struct apm_user * as;
1131 spin_lock(&user_list_lock);
1132 if (user_list == NULL)
1134 for (as = user_list; as != NULL; as = as->next) {
1135 if ((as == sender) || (!as->reader))
1137 if (++as->event_head >= APM_MAX_EVENTS)
1140 if (as->event_head == as->event_tail) {
1141 static int notified;
1143 if (notified++ == 0)
1144 printk(KERN_ERR "apm: an event queue overflowed\n");
1145 if (++as->event_tail >= APM_MAX_EVENTS)
1148 as->events[as->event_head] = event;
1149 if ((!as->suser) || (!as->writer))
1152 case APM_SYS_SUSPEND:
1153 case APM_USER_SUSPEND:
1154 as->suspends_pending++;
1158 case APM_SYS_STANDBY:
1159 case APM_USER_STANDBY:
1160 as->standbys_pending++;
1165 wake_up_interruptible(&apm_waitqueue);
1167 spin_unlock(&user_list_lock);
1170 static void reinit_timer(void)
1172 #ifdef INIT_TIMER_AFTER_SUSPEND
1173 unsigned long flags;
1175 spin_lock_irqsave(&i8253_lock, flags);
1176 /* set the clock to HZ */
1177 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1179 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1181 outb(LATCH >> 8, PIT_CH0); /* MSB */
1183 spin_unlock_irqrestore(&i8253_lock, flags);
1187 static int suspend(int vetoable)
1190 struct apm_user *as;
1192 if (pm_send_all(PM_SUSPEND, (void *)3)) {
1195 if (apm_info.connection_version > 0x100)
1196 set_system_power_state(APM_STATE_REJECT);
1198 ignore_sys_suspend = 0;
1199 printk(KERN_WARNING "apm: suspend was vetoed.\n");
1202 printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
1205 device_suspend(PMSG_SUSPEND);
1206 local_irq_disable();
1207 device_power_down(PMSG_SUSPEND);
1211 save_processor_state();
1212 err = set_system_power_state(APM_STATE_SUSPEND);
1213 ignore_normal_resume = 1;
1214 restore_processor_state();
1216 local_irq_disable();
1219 if (err == APM_NO_ERROR)
1221 if (err != APM_SUCCESS)
1222 apm_error("suspend", err);
1223 err = (err == APM_SUCCESS) ? 0 : -EIO;
1227 pm_send_all(PM_RESUME, (void *)0);
1228 queue_event(APM_NORMAL_RESUME, NULL);
1230 spin_lock(&user_list_lock);
1231 for (as = user_list; as != NULL; as = as->next) {
1232 as->suspend_wait = 0;
1233 as->suspend_result = err;
1235 spin_unlock(&user_list_lock);
1236 wake_up_interruptible(&apm_suspend_waitqueue);
1240 static void standby(void)
1244 local_irq_disable();
1245 device_power_down(PMSG_SUSPEND);
1248 err = set_system_power_state(APM_STATE_STANDBY);
1249 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1250 apm_error("standby", err);
1252 local_irq_disable();
1257 static apm_event_t get_event(void)
1260 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1261 apm_eventinfo_t info;
1263 static int notified;
1265 /* we don't use the eventinfo */
1266 error = apm_get_event(&event, &info);
1267 if (error == APM_SUCCESS)
1270 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1271 apm_error("get_event", error);
1276 static void check_events(void)
1279 static unsigned long last_resume;
1280 static int ignore_bounce;
1282 while ((event = get_event()) != 0) {
1284 if (event <= NR_APM_EVENT_NAME)
1285 printk(KERN_DEBUG "apm: received %s notify\n",
1286 apm_event_name[event - 1]);
1288 printk(KERN_DEBUG "apm: received unknown "
1289 "event 0x%02x\n", event);
1292 && ((jiffies - last_resume) > bounce_interval))
1296 case APM_SYS_STANDBY:
1297 case APM_USER_STANDBY:
1298 queue_event(event, NULL);
1299 if (standbys_pending <= 0)
1303 case APM_USER_SUSPEND:
1304 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1305 if (apm_info.connection_version > 0x100)
1306 set_system_power_state(APM_STATE_REJECT);
1309 case APM_SYS_SUSPEND:
1310 if (ignore_bounce) {
1311 if (apm_info.connection_version > 0x100)
1312 set_system_power_state(APM_STATE_REJECT);
1316 * If we are already processing a SUSPEND,
1317 * then further SUSPEND events from the BIOS
1318 * will be ignored. We also return here to
1319 * cope with the fact that the Thinkpads keep
1320 * sending a SUSPEND event until something else
1323 if (ignore_sys_suspend)
1325 ignore_sys_suspend = 1;
1326 queue_event(event, NULL);
1327 if (suspends_pending <= 0)
1331 case APM_NORMAL_RESUME:
1332 case APM_CRITICAL_RESUME:
1333 case APM_STANDBY_RESUME:
1334 ignore_sys_suspend = 0;
1335 last_resume = jiffies;
1337 if ((event != APM_NORMAL_RESUME)
1338 || (ignore_normal_resume == 0)) {
1340 pm_send_all(PM_RESUME, (void *)0);
1341 queue_event(event, NULL);
1343 ignore_normal_resume = 0;
1346 case APM_CAPABILITY_CHANGE:
1347 case APM_LOW_BATTERY:
1348 case APM_POWER_STATUS_CHANGE:
1349 queue_event(event, NULL);
1350 /* If needed, notify drivers here */
1353 case APM_UPDATE_TIME:
1356 case APM_CRITICAL_SUSPEND:
1358 * We are not allowed to reject a critical suspend.
1366 static void apm_event_handler(void)
1368 static int pending_count = 4;
1371 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1372 if ((apm_info.connection_version > 0x100) &&
1373 (pending_count-- <= 0)) {
1376 printk(KERN_DEBUG "apm: setting state busy\n");
1377 err = set_system_power_state(APM_STATE_BUSY);
1379 apm_error("busy", err);
1387 * This is the APM thread main loop.
1390 static void apm_mainloop(void)
1392 DECLARE_WAITQUEUE(wait, current);
1394 add_wait_queue(&apm_waitqueue, &wait);
1395 set_current_state(TASK_INTERRUPTIBLE);
1397 schedule_timeout(APM_CHECK_TIMEOUT);
1398 if (kthread_should_stop())
1401 * Ok, check all events, check for idle (and mark us sleeping
1402 * so as not to count towards the load average)..
1404 set_current_state(TASK_INTERRUPTIBLE);
1405 apm_event_handler();
1407 remove_wait_queue(&apm_waitqueue, &wait);
1410 static int check_apm_user(struct apm_user *as, const char *func)
1412 if ((as == NULL) || (as->magic != APM_BIOS_MAGIC)) {
1413 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1419 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1421 struct apm_user * as;
1425 as = fp->private_data;
1426 if (check_apm_user(as, "read"))
1428 if ((int)count < sizeof(apm_event_t))
1430 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1432 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1434 while ((i >= sizeof(event)) && !queue_empty(as)) {
1435 event = get_queued_event(as);
1436 if (copy_to_user(buf, &event, sizeof(event))) {
1442 case APM_SYS_SUSPEND:
1443 case APM_USER_SUSPEND:
1444 as->suspends_read++;
1447 case APM_SYS_STANDBY:
1448 case APM_USER_STANDBY:
1449 as->standbys_read++;
1452 buf += sizeof(event);
1457 if (signal_pending(current))
1458 return -ERESTARTSYS;
1462 static unsigned int do_poll(struct file *fp, poll_table * wait)
1464 struct apm_user * as;
1466 as = fp->private_data;
1467 if (check_apm_user(as, "poll"))
1469 poll_wait(fp, &apm_waitqueue, wait);
1470 if (!queue_empty(as))
1471 return POLLIN | POLLRDNORM;
1475 static int do_ioctl(struct inode * inode, struct file *filp,
1476 u_int cmd, u_long arg)
1478 struct apm_user * as;
1480 as = filp->private_data;
1481 if (check_apm_user(as, "ioctl"))
1483 if ((!as->suser) || (!as->writer))
1486 case APM_IOC_STANDBY:
1487 if (as->standbys_read > 0) {
1488 as->standbys_read--;
1489 as->standbys_pending--;
1492 queue_event(APM_USER_STANDBY, as);
1493 if (standbys_pending <= 0)
1496 case APM_IOC_SUSPEND:
1497 if (as->suspends_read > 0) {
1498 as->suspends_read--;
1499 as->suspends_pending--;
1502 queue_event(APM_USER_SUSPEND, as);
1503 if (suspends_pending <= 0) {
1506 as->suspend_wait = 1;
1507 wait_event_interruptible(apm_suspend_waitqueue,
1508 as->suspend_wait == 0);
1509 return as->suspend_result;
1518 static int do_release(struct inode * inode, struct file * filp)
1520 struct apm_user * as;
1522 as = filp->private_data;
1523 if (check_apm_user(as, "release"))
1525 filp->private_data = NULL;
1526 if (as->standbys_pending > 0) {
1527 standbys_pending -= as->standbys_pending;
1528 if (standbys_pending <= 0)
1531 if (as->suspends_pending > 0) {
1532 suspends_pending -= as->suspends_pending;
1533 if (suspends_pending <= 0)
1536 spin_lock(&user_list_lock);
1537 if (user_list == as)
1538 user_list = as->next;
1540 struct apm_user * as1;
1542 for (as1 = user_list;
1543 (as1 != NULL) && (as1->next != as);
1547 printk(KERN_ERR "apm: filp not in user list\n");
1549 as1->next = as->next;
1551 spin_unlock(&user_list_lock);
1556 static int do_open(struct inode * inode, struct file * filp)
1558 struct apm_user * as;
1560 as = kmalloc(sizeof(*as), GFP_KERNEL);
1562 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1566 as->magic = APM_BIOS_MAGIC;
1567 as->event_tail = as->event_head = 0;
1568 as->suspends_pending = as->standbys_pending = 0;
1569 as->suspends_read = as->standbys_read = 0;
1571 * XXX - this is a tiny bit broken, when we consider BSD
1572 * process accounting. If the device is opened by root, we
1573 * instantly flag that we used superuser privs. Who knows,
1574 * we might close the device immediately without doing a
1575 * privileged operation -- cevans
1577 as->suser = capable(CAP_SYS_ADMIN);
1578 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1579 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1580 spin_lock(&user_list_lock);
1581 as->next = user_list;
1583 spin_unlock(&user_list_lock);
1584 filp->private_data = as;
1588 static int proc_apm_show(struct seq_file *m, void *v)
1594 unsigned short ac_line_status = 0xff;
1595 unsigned short battery_status = 0xff;
1596 unsigned short battery_flag = 0xff;
1597 int percentage = -1;
1598 int time_units = -1;
1601 if ((num_online_cpus() == 1) &&
1602 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1603 ac_line_status = (bx >> 8) & 0xff;
1604 battery_status = bx & 0xff;
1605 if ((cx & 0xff) != 0xff)
1606 percentage = cx & 0xff;
1608 if (apm_info.connection_version > 0x100) {
1609 battery_flag = (cx >> 8) & 0xff;
1611 units = (dx & 0x8000) ? "min" : "sec";
1612 time_units = dx & 0x7fff;
1616 /* Arguments, with symbols from linux/apm_bios.h. Information is
1617 from the Get Power Status (0x0a) call unless otherwise noted.
1619 0) Linux driver version (this will change if format changes)
1620 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1621 2) APM flags from APM Installation Check (0x00):
1622 bit 0: APM_16_BIT_SUPPORT
1623 bit 1: APM_32_BIT_SUPPORT
1624 bit 2: APM_IDLE_SLOWS_CLOCK
1625 bit 3: APM_BIOS_DISABLED
1626 bit 4: APM_BIOS_DISENGAGED
1630 0x02: On backup power (BIOS >= 1.1 only)
1637 0x04: Selected battery not present (BIOS >= 1.2 only)
1644 bit 7: No system battery
1646 6) Remaining battery life (percentage of charge):
1649 7) Remaining battery life (time units):
1650 Number of remaining minutes or seconds
1652 8) min = minutes; sec = seconds */
1654 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1656 (apm_info.bios.version >> 8) & 0xff,
1657 apm_info.bios.version & 0xff,
1658 apm_info.bios.flags,
1668 static int proc_apm_open(struct inode *inode, struct file *file)
1670 return single_open(file, proc_apm_show, NULL);
1673 static const struct file_operations apm_file_ops = {
1674 .owner = THIS_MODULE,
1675 .open = proc_apm_open,
1677 .llseek = seq_lseek,
1678 .release = single_release,
1681 static int apm(void *unused)
1692 * This is to avoid random crashes at boot time during initialization
1693 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1694 * Some bioses don't like being called from CPU != 0.
1695 * Method suggested by Ingo Molnar.
1697 set_cpus_allowed(current, cpumask_of_cpu(0));
1698 BUG_ON(smp_processor_id() != 0);
1701 if (apm_info.connection_version == 0) {
1702 apm_info.connection_version = apm_info.bios.version;
1703 if (apm_info.connection_version > 0x100) {
1705 * We only support BIOSs up to version 1.2
1707 if (apm_info.connection_version > 0x0102)
1708 apm_info.connection_version = 0x0102;
1709 error = apm_driver_version(&apm_info.connection_version);
1710 if (error != APM_SUCCESS) {
1711 apm_error("driver version", error);
1712 /* Fall back to an APM 1.0 connection. */
1713 apm_info.connection_version = 0x100;
1719 printk(KERN_INFO "apm: Connection version %d.%d\n",
1720 (apm_info.connection_version >> 8) & 0xff,
1721 apm_info.connection_version & 0xff);
1723 #ifdef CONFIG_APM_DO_ENABLE
1724 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1726 * This call causes my NEC UltraLite Versa 33/C to hang if it
1727 * is booted with PM disabled but not in the docking station.
1730 error = apm_enable_power_management(1);
1732 apm_error("enable power management", error);
1738 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1739 && (apm_info.connection_version > 0x0100)) {
1740 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1742 apm_error("engage power management", error);
1747 if (debug && (num_online_cpus() == 1 || smp )) {
1748 error = apm_get_power_status(&bx, &cx, &dx);
1750 printk(KERN_INFO "apm: power status not available\n");
1752 switch ((bx >> 8) & 0xff) {
1753 case 0: power_stat = "off line"; break;
1754 case 1: power_stat = "on line"; break;
1755 case 2: power_stat = "on backup power"; break;
1756 default: power_stat = "unknown"; break;
1758 switch (bx & 0xff) {
1759 case 0: bat_stat = "high"; break;
1760 case 1: bat_stat = "low"; break;
1761 case 2: bat_stat = "critical"; break;
1762 case 3: bat_stat = "charging"; break;
1763 default: bat_stat = "unknown"; break;
1766 "apm: AC %s, battery status %s, battery life ",
1767 power_stat, bat_stat);
1768 if ((cx & 0xff) == 0xff)
1769 printk("unknown\n");
1771 printk("%d%%\n", cx & 0xff);
1772 if (apm_info.connection_version > 0x100) {
1774 "apm: battery flag 0x%02x, battery life ",
1777 printk("unknown\n");
1779 printk("%d %s\n", dx & 0x7fff,
1781 "minutes" : "seconds");
1786 /* Install our power off handler.. */
1788 pm_power_off = apm_power_off;
1790 if (num_online_cpus() == 1 || smp) {
1791 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1792 console_blank_hook = apm_console_blank;
1795 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1796 console_blank_hook = NULL;
1804 static int __init apm_setup(char *str)
1808 while ((str != NULL) && (*str != '\0')) {
1809 if (strncmp(str, "off", 3) == 0)
1811 if (strncmp(str, "on", 2) == 0)
1813 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1814 (strncmp(str, "bounce_interval=", 16) == 0))
1815 bounce_interval = simple_strtol(str + 16, NULL, 0);
1816 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1817 (strncmp(str, "idle_threshold=", 15) == 0))
1818 idle_threshold = simple_strtol(str + 15, NULL, 0);
1819 if ((strncmp(str, "idle-period=", 12) == 0) ||
1820 (strncmp(str, "idle_period=", 12) == 0))
1821 idle_period = simple_strtol(str + 12, NULL, 0);
1822 invert = (strncmp(str, "no-", 3) == 0) ||
1823 (strncmp(str, "no_", 3) == 0);
1826 if (strncmp(str, "debug", 5) == 0)
1828 if ((strncmp(str, "power-off", 9) == 0) ||
1829 (strncmp(str, "power_off", 9) == 0))
1830 power_off = !invert;
1831 if (strncmp(str, "smp", 3) == 0)
1834 idle_threshold = 100;
1836 if ((strncmp(str, "allow-ints", 10) == 0) ||
1837 (strncmp(str, "allow_ints", 10) == 0))
1838 apm_info.allow_ints = !invert;
1839 if ((strncmp(str, "broken-psr", 10) == 0) ||
1840 (strncmp(str, "broken_psr", 10) == 0))
1841 apm_info.get_power_status_broken = !invert;
1842 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1843 (strncmp(str, "realmode_power_off", 18) == 0))
1844 apm_info.realmode_power_off = !invert;
1845 str = strchr(str, ',');
1847 str += strspn(str, ", \t");
1852 __setup("apm=", apm_setup);
1855 static const struct file_operations apm_bios_fops = {
1856 .owner = THIS_MODULE,
1861 .release = do_release,
1864 static struct miscdevice apm_device = {
1871 /* Simple "print if true" callback */
1872 static int __init print_if_true(const struct dmi_system_id *d)
1874 printk("%s\n", d->ident);
1879 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1880 * disabled before the suspend. Linux used to get terribly confused by that.
1882 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1884 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug workaround hopefully not needed.\n", d->ident);
1888 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1889 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1891 if (apm_info.realmode_power_off == 0) {
1892 apm_info.realmode_power_off = 1;
1893 printk(KERN_INFO "%s bios detected. Using realmode poweroff only.\n", d->ident);
1898 /* Some laptops require interrupts to be enabled during APM calls */
1899 static int __init set_apm_ints(const struct dmi_system_id *d)
1901 if (apm_info.allow_ints == 0) {
1902 apm_info.allow_ints = 1;
1903 printk(KERN_INFO "%s machine detected. Enabling interrupts during APM calls.\n", d->ident);
1908 /* Some APM bioses corrupt memory or just plain do not work */
1909 static int __init apm_is_horked(const struct dmi_system_id *d)
1911 if (apm_info.disabled == 0) {
1912 apm_info.disabled = 1;
1913 printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
1918 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1920 if (apm_info.disabled == 0) {
1921 apm_info.disabled = 1;
1922 printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
1923 printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
1924 printk(KERN_INFO "download from support.intel.com \n");
1929 /* Some APM bioses hang on APM idle calls */
1930 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1932 if (apm_info.forbid_idle == 0) {
1933 apm_info.forbid_idle = 1;
1934 printk(KERN_INFO "%s machine detected. Disabling APM idle calls.\n", d->ident);
1940 * Check for clue free BIOS implementations who use
1941 * the following QA technique
1943 * [ Write BIOS Code ]<------
1945 * < Does it Compile >----N--
1947 * < Does it Boot Win98 >-N--
1951 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
1952 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
1954 static int __init broken_apm_power(const struct dmi_system_id *d)
1956 apm_info.get_power_status_broken = 1;
1957 printk(KERN_WARNING "BIOS strings suggest APM bugs, disabling power status reporting.\n");
1962 * This bios swaps the APM minute reporting bytes over (Many sony laptops
1963 * have this problem).
1965 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
1967 apm_info.get_power_status_swabinminutes = 1;
1968 printk(KERN_WARNING "BIOS strings suggest APM reports battery life in minutes and wrong byte order.\n");
1972 static struct dmi_system_id __initdata apm_dmi_table[] = {
1975 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
1976 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
1977 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
1979 { /* Handle problems with APM on the C600 */
1980 broken_ps2_resume, "Dell Latitude C600",
1981 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
1982 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
1984 { /* Allow interrupts during suspend on Dell Latitude laptops*/
1985 set_apm_ints, "Dell Latitude",
1986 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
1987 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
1990 apm_is_horked, "Dell Inspiron 2500",
1991 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
1992 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
1993 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
1994 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
1996 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
1997 set_apm_ints, "Dell Inspiron", {
1998 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
1999 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2001 { /* Handle problems with APM on Inspiron 5000e */
2002 broken_apm_power, "Dell Inspiron 5000e",
2003 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2004 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2005 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2007 { /* Handle problems with APM on Inspiron 2500 */
2008 broken_apm_power, "Dell Inspiron 2500",
2009 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2010 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2011 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2014 apm_is_horked, "Dell Dimension 4100",
2015 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2016 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2017 DMI_MATCH(DMI_BIOS_VENDOR,"Intel Corp."),
2018 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2020 { /* Allow interrupts during suspend on Compaq Laptops*/
2021 set_apm_ints, "Compaq 12XL125",
2022 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2023 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2024 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2025 DMI_MATCH(DMI_BIOS_VERSION,"4.06"), },
2027 { /* Allow interrupts during APM or the clock goes slow */
2028 set_apm_ints, "ASUSTeK",
2029 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2030 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2032 { /* APM blows on shutdown */
2033 apm_is_horked, "ABIT KX7-333[R]",
2034 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2035 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2038 apm_is_horked, "Trigem Delhi3",
2039 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2040 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2043 apm_is_horked, "Fujitsu-Siemens",
2044 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2045 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2048 apm_is_horked_d850md, "Intel D850MD",
2049 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2050 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2053 apm_is_horked, "Intel D810EMO",
2054 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2055 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2058 apm_is_horked, "Dell XPS-Z",
2059 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2060 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2061 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2064 apm_is_horked, "Sharp PC-PJ/AX",
2065 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2066 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2067 DMI_MATCH(DMI_BIOS_VENDOR,"SystemSoft"),
2068 DMI_MATCH(DMI_BIOS_VERSION,"Version R2.08"), },
2071 apm_is_horked, "Dell Inspiron 2500",
2072 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2073 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2074 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
2075 DMI_MATCH(DMI_BIOS_VERSION,"A11"), },
2077 { /* APM idle hangs */
2078 apm_likes_to_melt, "Jabil AMD",
2079 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2080 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2082 { /* APM idle hangs */
2083 apm_likes_to_melt, "AMI Bios",
2084 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2085 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2087 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2088 swab_apm_power_in_minutes, "Sony VAIO",
2089 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2090 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2091 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2093 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2094 swab_apm_power_in_minutes, "Sony VAIO",
2095 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2096 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2097 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2099 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2100 swab_apm_power_in_minutes, "Sony VAIO",
2101 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2102 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2103 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2105 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2106 swab_apm_power_in_minutes, "Sony VAIO",
2107 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2108 DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2109 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2111 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2112 swab_apm_power_in_minutes, "Sony VAIO",
2113 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2114 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2115 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2117 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2118 swab_apm_power_in_minutes, "Sony VAIO",
2119 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2120 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2121 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2123 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2124 swab_apm_power_in_minutes, "Sony VAIO",
2125 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2126 DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2127 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2129 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2130 swab_apm_power_in_minutes, "Sony VAIO",
2131 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2132 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2133 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2135 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2136 swab_apm_power_in_minutes, "Sony VAIO",
2137 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2138 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2139 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2141 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2142 swab_apm_power_in_minutes, "Sony VAIO",
2143 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2144 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2145 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2148 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2149 swab_apm_power_in_minutes, "Sony VAIO",
2150 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2151 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2152 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2154 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2155 swab_apm_power_in_minutes, "Sony VAIO",
2156 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2157 DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2158 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2160 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2161 swab_apm_power_in_minutes, "Sony VAIO",
2162 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2163 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2164 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2166 { /* broken PM poweroff bios */
2167 set_realmode_power_off, "Award Software v4.60 PGMA",
2168 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2169 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2170 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2173 /* Generic per vendor APM settings */
2175 { /* Allow interrupts during suspend on IBM laptops */
2176 set_apm_ints, "IBM",
2177 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2184 * Just start the APM thread. We do NOT want to do APM BIOS
2185 * calls from anything but the APM thread, if for no other reason
2186 * than the fact that we don't trust the APM BIOS. This way,
2187 * most common APM BIOS problems that lead to protection errors
2188 * etc will have at least some level of being contained...
2190 * In short, if something bad happens, at least we have a choice
2191 * of just killing the apm thread..
2193 static int __init apm_init(void)
2195 struct proc_dir_entry *apm_proc;
2196 struct desc_struct *gdt;
2199 dmi_check_system(apm_dmi_table);
2201 if (apm_info.bios.version == 0 || paravirt_enabled()) {
2202 printk(KERN_INFO "apm: BIOS not found.\n");
2206 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2207 ((apm_info.bios.version >> 8) & 0xff),
2208 (apm_info.bios.version & 0xff),
2209 apm_info.bios.flags,
2211 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2212 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2217 apm_info.allow_ints = 1;
2219 apm_info.get_power_status_broken = 1;
2220 if (realmode_power_off)
2221 apm_info.realmode_power_off = 1;
2222 /* User can override, but default is to trust DMI */
2223 if (apm_disabled != -1)
2224 apm_info.disabled = apm_disabled;
2227 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2228 * but is reportedly a 1.0 BIOS.
2230 if (apm_info.bios.version == 0x001)
2231 apm_info.bios.version = 0x100;
2233 /* BIOS < 1.2 doesn't set cseg_16_len */
2234 if (apm_info.bios.version < 0x102)
2235 apm_info.bios.cseg_16_len = 0; /* 64k */
2238 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2239 apm_info.bios.cseg, apm_info.bios.offset,
2240 apm_info.bios.cseg_16, apm_info.bios.dseg);
2241 if (apm_info.bios.version > 0x100)
2242 printk(" cseg len %x, dseg len %x",
2243 apm_info.bios.cseg_len,
2244 apm_info.bios.dseg_len);
2245 if (apm_info.bios.version > 0x101)
2246 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2250 if (apm_info.disabled) {
2251 printk(KERN_NOTICE "apm: disabled on user request.\n");
2254 if ((num_online_cpus() > 1) && !power_off && !smp) {
2255 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2256 apm_info.disabled = 1;
2259 if (PM_IS_ACTIVE()) {
2260 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2261 apm_info.disabled = 1;
2264 #ifdef CONFIG_PM_LEGACY
2269 * Set up a segment that references the real mode segment 0x40
2270 * that extends up to the end of page zero (that we have reserved).
2271 * This is for buggy BIOS's that refer to (real mode) segment 0x40
2272 * even though they are called in protected mode.
2274 set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2275 _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2278 * Set up the long jump entry point to the APM BIOS, which is called
2279 * from inline assembly.
2281 apm_bios_entry.offset = apm_info.bios.offset;
2282 apm_bios_entry.segment = APM_CS;
2285 * The APM 1.1 BIOS is supposed to provide limit information that it
2286 * recognizes. Many machines do this correctly, but many others do
2287 * not restrict themselves to their claimed limit. When this happens,
2288 * they will cause a segmentation violation in the kernel at boot time.
2289 * Most BIOS's, however, will respect a 64k limit, so we use that.
2291 * Note we only set APM segments on CPU zero, since we pin the APM
2294 gdt = get_cpu_gdt_table(0);
2295 set_base(gdt[APM_CS >> 3],
2296 __va((unsigned long)apm_info.bios.cseg << 4));
2297 set_base(gdt[APM_CS_16 >> 3],
2298 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2299 set_base(gdt[APM_DS >> 3],
2300 __va((unsigned long)apm_info.bios.dseg << 4));
2302 apm_proc = create_proc_entry("apm", 0, NULL);
2304 apm_proc->proc_fops = &apm_file_ops;
2306 kapmd_task = kthread_create(apm, NULL, "kapmd");
2307 if (IS_ERR(kapmd_task)) {
2308 printk(KERN_ERR "apm: disabled - Unable to start kernel "
2310 err = PTR_ERR(kapmd_task);
2312 remove_proc_entry("apm", NULL);
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);