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Diffstat (limited to 'arch/x86/kernel/apm_32.c')
| -rw-r--r-- | arch/x86/kernel/apm_32.c | 2403 |
1 files changed, 2403 insertions, 0 deletions
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c new file mode 100644 index 00000000000..32f2365c26e --- /dev/null +++ b/arch/x86/kernel/apm_32.c @@ -0,0 +1,2403 @@ +/* -*- linux-c -*- + * APM BIOS driver for Linux + * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au) + * + * Initial development of this driver was funded by NEC Australia P/L + * and NEC Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * October 1995, Rik Faith (faith@cs.unc.edu): + * Minor enhancements and updates (to the patch set) for 1.3.x + * Documentation + * January 1996, Rik Faith (faith@cs.unc.edu): + * Make /proc/apm easy to format (bump driver version) + * March 1996, Rik Faith (faith@cs.unc.edu): + * Prohibit APM BIOS calls unless apm_enabled. + * (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>) + * April 1996, Stephen Rothwell (sfr@canb.auug.org.au) + * Version 1.0 and 1.1 + * May 1996, Version 1.2 + * Feb 1998, Version 1.3 + * Feb 1998, Version 1.4 + * Aug 1998, Version 1.5 + * Sep 1998, Version 1.6 + * Nov 1998, Version 1.7 + * Jan 1999, Version 1.8 + * Jan 1999, Version 1.9 + * Oct 1999, Version 1.10 + * Nov 1999, Version 1.11 + * Jan 2000, Version 1.12 + * Feb 2000, Version 1.13 + * Nov 2000, Version 1.14 + * Oct 2001, Version 1.15 + * Jan 2002, Version 1.16 + * Oct 2002, Version 1.16ac + * + * History: + * 0.6b: first version in official kernel, Linux 1.3.46 + * 0.7: changed /proc/apm format, Linux 1.3.58 + * 0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59 + * 0.9: only call bios if bios is present, Linux 1.3.72 + * 1.0: use fixed device number, consolidate /proc/apm into this file, + * Linux 1.3.85 + * 1.1: support user-space standby and suspend, power off after system + * halted, Linux 1.3.98 + * 1.2: When resetting RTC after resume, take care so that the time + * is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth + * <jtoth@princeton.edu>); improve interaction between + * screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4 + * 1.2a:Simple change to stop mysterious bug reports with SMP also added + * levels to the printk calls. APM is not defined for SMP machines. + * The new replacment for it is, but Linux doesn't yet support this. + * Alan Cox Linux 2.1.55 + * 1.3: Set up a valid data descriptor 0x40 for buggy BIOS's + * 1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by + * Dean Gaudet <dgaudet@arctic.org>. + * C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87 + * 1.5: Fix segment register reloading (in case of bad segments saved + * across BIOS call). + * Stephen Rothwell + * 1.6: Cope with complier/assembler differences. + * Only try to turn off the first display device. + * Fix OOPS at power off with no APM BIOS by Jan Echternach + * <echter@informatik.uni-rostock.de> + * Stephen Rothwell + * 1.7: Modify driver's cached copy of the disabled/disengaged flags + * to reflect current state of APM BIOS. + * Chris Rankin <rankinc@bellsouth.net> + * Reset interrupt 0 timer to 100Hz after suspend + * Chad Miller <cmiller@surfsouth.com> + * Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE + * Richard Gooch <rgooch@atnf.csiro.au> + * Allow boot time disabling of APM + * Make boot messages far less verbose by default + * Make asm safer + * Stephen Rothwell + * 1.8: Add CONFIG_APM_RTC_IS_GMT + * Richard Gooch <rgooch@atnf.csiro.au> + * change APM_NOINTS to CONFIG_APM_ALLOW_INTS + * remove dependency on CONFIG_PROC_FS + * Stephen Rothwell + * 1.9: Fix small typo. <laslo@wodip.opole.pl> + * Try to cope with BIOS's that need to have all display + * devices blanked and not just the first one. + * Ross Paterson <ross@soi.city.ac.uk> + * Fix segment limit setting it has always been wrong as + * the segments needed to have byte granularity. + * Mark a few things __init. + * Add hack to allow power off of SMP systems by popular request. + * Use CONFIG_SMP instead of __SMP__ + * Ignore BOUNCES for three seconds. + * Stephen Rothwell + * 1.10: Fix for Thinkpad return code. + * Merge 2.2 and 2.3 drivers. + * Remove APM dependencies in arch/i386/kernel/process.c + * Remove APM dependencies in drivers/char/sysrq.c + * Reset time across standby. + * Allow more inititialisation on SMP. + * Remove CONFIG_APM_POWER_OFF and make it boot time + * configurable (default on). + * Make debug only a boot time parameter (remove APM_DEBUG). + * Try to blank all devices on any error. + * 1.11: Remove APM dependencies in drivers/char/console.c + * Check nr_running to detect if we are idle (from + * Borislav Deianov <borislav@lix.polytechnique.fr>) + * Fix for bioses that don't zero the top part of the + * entrypoint offset (Mario Sitta <sitta@al.unipmn.it>) + * (reported by Panos Katsaloulis <teras@writeme.com>). + * Real mode power off patch (Walter Hofmann + * <Walter.Hofmann@physik.stud.uni-erlangen.de>). + * 1.12: Remove CONFIG_SMP as the compiler will optimize + * the code away anyway (smp_num_cpus == 1 in UP) + * noted by Artur Skawina <skawina@geocities.com>. + * Make power off under SMP work again. + * Fix thinko with initial engaging of BIOS. + * Make sure power off only happens on CPU 0 + * (Paul "Rusty" Russell <rusty@rustcorp.com.au>). + * Do error notification to user mode if BIOS calls fail. + * Move entrypoint offset fix to ...boot/setup.S + * where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>). + * Remove smp-power-off. SMP users must now specify + * "apm=power-off" on the kernel command line. Suggested + * by Jim Avera <jima@hal.com>, modified by Alan Cox + * <alan@lxorguk.ukuu.org.uk>. + * Register the /proc/apm entry even on SMP so that + * scripts that check for it before doing power off + * work (Jim Avera <jima@hal.com>). + * 1.13: Changes for new pm_ interfaces (Andy Henroid + * <andy_henroid@yahoo.com>). + * Modularize the code. + * Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS + * is now the way life works). + * Fix thinko in suspend() (wrong return). + * Notify drivers on critical suspend. + * Make kapmd absorb more idle time (Pavel Machek <pavel@suse.cz> + * modified by sfr). + * Disable interrupts while we are suspended (Andy Henroid + * <andy_henroid@yahoo.com> fixed by sfr). + * Make power off work on SMP again (Tony Hoyle + * <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr. + * Remove CONFIG_APM_SUSPEND_BOUNCE. The bounce ignore + * interval is now configurable. + * 1.14: Make connection version persist across module unload/load. + * Enable and engage power management earlier. + * Disengage power management on module unload. + * Changed to use the sysrq-register hack for registering the + * power off function called by magic sysrq based upon discussions + * in irc://irc.openprojects.net/#kernelnewbies + * (Crutcher Dunnavant <crutcher+kernel@datastacks.com>). + * Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable. + * (Arjan van de Ven <arjanv@redhat.com>) modified by sfr. + * Work around byte swap bug in one of the Vaio's BIOS's + * (Marc Boucher <marc@mbsi.ca>). + * Exposed the disable flag to dmi so that we can handle known + * broken APM (Alan Cox <alan@redhat.com>). + * 1.14ac: If the BIOS says "I slowed the CPU down" then don't spin + * calling it - instead idle. (Alan Cox <alan@redhat.com>) + * If an APM idle fails log it and idle sensibly + * 1.15: Don't queue events to clients who open the device O_WRONLY. + * Don't expect replies from clients who open the device O_RDONLY. + * (Idea from Thomas Hood) + * Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>) + * 1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.) + * Notify listeners of standby or suspend events before notifying + * drivers. Return EBUSY to ioctl() if suspend is rejected. + * (Russell King <rmk@arm.linux.org.uk> and Thomas Hood) + * Ignore first resume after we generate our own resume event + * after a suspend (Thomas Hood) + * Daemonize now gets rid of our controlling terminal (sfr). + * CONFIG_APM_CPU_IDLE now just affects the default value of + * idle_threshold (sfr). + * Change name of kernel apm daemon (as it no longer idles) (sfr). + * 1.16ac: Fix up SMP support somewhat. You can now force SMP on and we + * make _all_ APM calls on the CPU#0. Fix unsafe sign bug. + * TODO: determine if its "boot CPU" or "CPU0" we want to lock to. + * + * APM 1.1 Reference: + * + * Intel Corporation, Microsoft Corporation. Advanced Power Management + * (APM) BIOS Interface Specification, Revision 1.1, September 1993. + * Intel Order Number 241704-001. Microsoft Part Number 781-110-X01. + * + * [This document is available free from Intel by calling 800.628.8686 (fax + * 916.356.6100) or 800.548.4725; or via anonymous ftp from + * ftp://ftp.intel.com/pub/IAL/software_specs/apmv11.doc. It is also + * available from Microsoft by calling 206.882.8080.] + * + * APM 1.2 Reference: + * Intel Corporation, Microsoft Corporation. Advanced Power Management + * (APM) BIOS Interface Specification, Revision 1.2, February 1996. + * + * [This document is available from Microsoft at: + * http://www.microsoft.com/whdc/archive/amp_12.mspx] + */ + +#include <linux/module.h> + +#include <linux/poll.h> +#include <linux/types.h> +#include <linux/stddef.h> +#include <linux/timer.h> +#include <linux/fcntl.h> +#include <linux/slab.h> +#include <linux/stat.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/miscdevice.h> +#include <linux/apm_bios.h> +#include <linux/init.h> +#include <linux/time.h> +#include <linux/sched.h> +#include <linux/pm.h> +#include <linux/pm_legacy.h> +#include <linux/capability.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/freezer.h> +#include <linux/smp.h> +#include <linux/dmi.h> +#include <linux/suspend.h> +#include <linux/kthread.h> + +#include <asm/system.h> +#include <asm/uaccess.h> +#include <asm/desc.h> +#include <asm/i8253.h> +#include <asm/paravirt.h> +#include <asm/reboot.h> + +#include "io_ports.h" + +#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT) +extern int (*console_blank_hook)(int); +#endif + +/* + * The apm_bios device is one of the misc char devices. + * This is its minor number. + */ +#define APM_MINOR_DEV 134 + +/* + * See Documentation/Config.help for the configuration options. + * + * Various options can be changed at boot time as follows: + * (We allow underscores for compatibility with the modules code) + * apm=on/off enable/disable APM + * [no-]allow[-_]ints allow interrupts during BIOS calls + * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call + * [no-]realmode[-_]power[-_]off switch to real mode before + * powering off + * [no-]debug log some debugging messages + * [no-]power[-_]off power off on shutdown + * [no-]smp Use apm even on an SMP box + * bounce[-_]interval=<n> number of ticks to ignore suspend + * bounces + * idle[-_]threshold=<n> System idle percentage above which to + * make APM BIOS idle calls. Set it to + * 100 to disable. + * idle[-_]period=<n> Period (in 1/100s of a second) over + * which the idle percentage is + * calculated. + */ + +/* KNOWN PROBLEM MACHINES: + * + * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant + * [Confirmed by TI representative] + * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification + * [Confirmed by BIOS disassembly] + * [This may work now ...] + * P: Toshiba 1950S: battery life information only gets updated after resume + * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking + * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>] + * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP + * Neale Banks <neale@lowendale.com.au> December 2000 + * + * Legend: U = unusable with APM patches + * P = partially usable with APM patches + */ + +/* + * Define as 1 to make the driver always call the APM BIOS busy + * routine even if the clock was not reported as slowed by the + * idle routine. Otherwise, define as 0. + */ +#define ALWAYS_CALL_BUSY 1 + +/* + * Define to make the APM BIOS calls zero all data segment registers (so + * that an incorrect BIOS implementation will cause a kernel panic if it + * tries to write to arbitrary memory). + */ +#define APM_ZERO_SEGS + +#include "apm.h" + +/* + * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend. + * This patched by Chad Miller <cmiller@surfsouth.com>, original code by + * David Chen <chen@ctpa04.mit.edu> + */ +#undef INIT_TIMER_AFTER_SUSPEND + +#ifdef INIT_TIMER_AFTER_SUSPEND +#include <linux/timex.h> +#include <asm/io.h> +#include <linux/delay.h> +#endif + +/* + * Need to poll the APM BIOS every second + */ +#define APM_CHECK_TIMEOUT (HZ) + +/* + * Ignore suspend events for this amount of time after a resume + */ +#define DEFAULT_BOUNCE_INTERVAL (3 * HZ) + +/* + * Maximum number of events stored + */ +#define APM_MAX_EVENTS 20 + +/* + * The per-file APM data + */ +struct apm_user { + int magic; + struct apm_user * next; + unsigned int suser: 1; + unsigned int writer: 1; + unsigned int reader: 1; + unsigned int suspend_wait: 1; + int suspend_result; + int suspends_pending; + int standbys_pending; + int suspends_read; + int standbys_read; + int event_head; + int event_tail; + apm_event_t events[APM_MAX_EVENTS]; +}; + +/* + * The magic number in apm_user + */ +#define APM_BIOS_MAGIC 0x4101 + +/* + * idle percentage above which bios idle calls are done + */ +#ifdef CONFIG_APM_CPU_IDLE +#define DEFAULT_IDLE_THRESHOLD 95 +#else +#define DEFAULT_IDLE_THRESHOLD 100 +#endif +#define DEFAULT_IDLE_PERIOD (100 / 3) + +/* + * Local variables + */ +static struct { + unsigned long offset; + unsigned short segment; +} apm_bios_entry; +static int clock_slowed; +static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD; +static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD; +static int set_pm_idle; +static int suspends_pending; +static int standbys_pending; +static int ignore_sys_suspend; +static int ignore_normal_resume; +static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL; + +static int debug __read_mostly; +static int smp __read_mostly; +static int apm_disabled = -1; +#ifdef CONFIG_SMP +static int power_off; +#else +static int power_off = 1; +#endif +#ifdef CONFIG_APM_REAL_MODE_POWER_OFF +static int realmode_power_off = 1; +#else +static int realmode_power_off; +#endif +#ifdef CONFIG_APM_ALLOW_INTS +static int allow_ints = 1; +#else +static int allow_ints; +#endif +static int broken_psr; + +static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue); +static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue); +static struct apm_user * user_list; +static DEFINE_SPINLOCK(user_list_lock); +static const struct desc_struct bad_bios_desc = { 0, 0x00409200 }; + +static const char driver_version[] = "1.16ac"; /* no spaces */ + +static struct task_struct *kapmd_task; + +/* + * APM event names taken from the APM 1.2 specification. These are + * the message codes that the BIOS uses to tell us about events + */ +static const char * const apm_event_name[] = { + "system standby", + "system suspend", + "normal resume", + "critical resume", + "low battery", + "power status change", + "update time", + "critical suspend", + "user standby", + "user suspend", + "system standby resume", + "capabilities change" +}; +#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name) + +typedef struct lookup_t { + int key; + char * msg; +} lookup_t; + +/* + * The BIOS returns a set of standard error codes in AX when the + * carry flag is set. + */ + +static const lookup_t error_table[] = { +/* N/A { APM_SUCCESS, "Operation succeeded" }, */ + { APM_DISABLED, "Power management disabled" }, + { APM_CONNECTED, "Real mode interface already connected" }, + { APM_NOT_CONNECTED, "Interface not connected" }, + { APM_16_CONNECTED, "16 bit interface already connected" }, +/* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */ + { APM_32_CONNECTED, "32 bit interface already connected" }, + { APM_32_UNSUPPORTED, "32 bit interface not supported" }, + { APM_BAD_DEVICE, "Unrecognized device ID" }, + { APM_BAD_PARAM, "Parameter out of range" }, + { APM_NOT_ENGAGED, "Interface not engaged" }, + { APM_BAD_FUNCTION, "Function not supported" }, + { APM_RESUME_DISABLED, "Resume timer disabled" }, + { APM_BAD_STATE, "Unable to enter requested state" }, +/* N/A { APM_NO_EVENTS, "No events pending" }, */ + { APM_NO_ERROR, "BIOS did not set a return code" }, + { APM_NOT_PRESENT, "No APM present" } +}; +#define ERROR_COUNT ARRAY_SIZE(error_table) + +/** + * apm_error - display an APM error + * @str: information string + * @err: APM BIOS return code + * + * Write a meaningful log entry to the kernel log in the event of + * an APM error. + */ + +static void apm_error(char *str, int err) +{ + int i; + + for (i = 0; i < ERROR_COUNT; i++) + if (error_table[i].key == err) break; + if (i < ERROR_COUNT) + printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg); + else + printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n", + str, err); +} + +/* + * Lock APM functionality to physical CPU 0 + */ + +#ifdef CONFIG_SMP + +static cpumask_t apm_save_cpus(void) +{ + cpumask_t x = current->cpus_allowed; + /* Some bioses don't like being called from CPU != 0 */ + set_cpus_allowed(current, cpumask_of_cpu(0)); + BUG_ON(smp_processor_id() != 0); + return x; +} + +static inline void apm_restore_cpus(cpumask_t mask) +{ + set_cpus_allowed(current, mask); +} + +#else + +/* + * No CPU lockdown needed on a uniprocessor + */ + +#define apm_save_cpus() (current->cpus_allowed) +#define apm_restore_cpus(x) (void)(x) + +#endif + +/* + * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and + * apm_info.allow_ints, we are being really paranoid here! Not only + * are interrupts disabled, but all the segment registers (except SS) + * are saved and zeroed this means that if the BIOS tries to reference + * any data without explicitly loading the segment registers, the kernel + * will fault immediately rather than have some unforeseen circumstances + * for the rest of the kernel. And it will be very obvious! :-) Doing + * this depends on CS referring to the same physical memory as DS so that + * DS can be zeroed before the call. Unfortunately, we can't do anything + * about the stack segment/pointer. Also, we tell the compiler that + * everything could change. + * + * Also, we KNOW that for the non error case of apm_bios_call, there + * is no useful data returned in the low order 8 bits of eax. + */ + +static inline unsigned long __apm_irq_save(void) +{ + unsigned long flags; + local_save_flags(flags); + if (apm_info.allow_ints) { + if (irqs_disabled_flags(flags)) + local_irq_enable(); + } else + local_irq_disable(); + + return flags; +} + +#define apm_irq_save(flags) \ + do { flags = __apm_irq_save(); } while (0) + +static inline void apm_irq_restore(unsigned long flags) +{ + if (irqs_disabled_flags(flags)) + local_irq_disable(); + else if (irqs_disabled()) + local_irq_enable(); +} + +#ifdef APM_ZERO_SEGS +# define APM_DECL_SEGS \ + unsigned int saved_fs; unsigned int saved_gs; +# define APM_DO_SAVE_SEGS \ + savesegment(fs, saved_fs); savesegment(gs, saved_gs) +# define APM_DO_RESTORE_SEGS \ + loadsegment(fs, saved_fs); loadsegment(gs, saved_gs) +#else +# define APM_DECL_SEGS +# define APM_DO_SAVE_SEGS +# define APM_DO_RESTORE_SEGS +#endif + +/** + * apm_bios_call - Make an APM BIOS 32bit call + * @func: APM function to execute + * @ebx_in: EBX register for call entry + * @ecx_in: ECX register for call entry + * @eax: EAX register return + * @ebx: EBX register return + * @ecx: ECX register return + * @edx: EDX register return + * @esi: ESI register return + * + * Make an APM call using the 32bit protected mode interface. The + * caller is responsible for knowing if APM BIOS is configured and + * enabled. This call can disable interrupts for a long period of + * time on some laptops. The return value is in AH and the carry + * flag is loaded into AL. If there is an error, then the error + * code is returned in AH (bits 8-15 of eax) and this function + * returns non-zero. + */ + +static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in, + u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi) +{ + APM_DECL_SEGS + unsigned long flags; + cpumask_t cpus; + int cpu; + struct desc_struct save_desc_40; + struct desc_struct *gdt; + + cpus = apm_save_cpus(); + + cpu = get_cpu(); + gdt = get_cpu_gdt_table(cpu); + save_desc_40 = gdt[0x40 / 8]; + gdt[0x40 / 8] = bad_bios_desc; + + apm_irq_save(flags); + APM_DO_SAVE_SEGS; + apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi); + APM_DO_RESTORE_SEGS; + apm_irq_restore(flags); + gdt[0x40 / 8] = save_desc_40; + put_cpu(); + apm_restore_cpus(cpus); + + return *eax & 0xff; +} + +/** + * apm_bios_call_simple - make a simple APM BIOS 32bit call + * @func: APM function to invoke + * @ebx_in: EBX register value for BIOS call + * @ecx_in: ECX register value for BIOS call + * @eax: EAX register on return from the BIOS call + * + * Make a BIOS call that returns one value only, or just status. + * If there is an error, then the error code is returned in AH + * (bits 8-15 of eax) and this function returns non-zero. This is + * used for simpler BIOS operations. This call may hold interrupts + * off for a long time on some laptops. + */ + +static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax) +{ + u8 error; + APM_DECL_SEGS + unsigned long flags; + cpumask_t cpus; + int cpu; + struct desc_struct save_desc_40; + struct desc_struct *gdt; + + cpus = apm_save_cpus(); + + cpu = get_cpu(); + gdt = get_cpu_gdt_table(cpu); + save_desc_40 = gdt[0x40 / 8]; + gdt[0x40 / 8] = bad_bios_desc; + + apm_irq_save(flags); + APM_DO_SAVE_SEGS; + error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax); + APM_DO_RESTORE_SEGS; + apm_irq_restore(flags); + gdt[0x40 / 8] = save_desc_40; + put_cpu(); + apm_restore_cpus(cpus); + return error; +} + +/** + * apm_driver_version - APM driver version + * @val: loaded with the APM version on return + * + * Retrieve the APM version supported by the BIOS. This is only + * supported for APM 1.1 or higher. An error indicates APM 1.0 is + * probably present. + * + * On entry val should point to a value indicating the APM driver + * version with the high byte being the major and the low byte the + * minor number both in BCD + * + * On return it will hold the BIOS revision supported in the + * same format. + */ + +static int apm_driver_version(u_short *val) +{ + u32 eax; + + if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax)) + return (eax >> 8) & 0xff; + *val = eax; + return APM_SUCCESS; +} + +/** + * apm_get_event - get an APM event from the BIOS + * @event: pointer to the event + * @info: point to the event information + * + * The APM BIOS provides a polled information for event + * reporting. The BIOS expects to be polled at least every second + * when events are pending. When a message is found the caller should + * poll until no more messages are present. However, this causes + * problems on some laptops where a suspend event notification is + * not cleared until it is acknowledged. + * + * Additional information is returned in the info pointer, providing + * that APM 1.2 is in use. If no messges are pending the value 0x80 + * is returned (No power management events pending). + */ + +static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info) +{ + u32 eax; + u32 ebx; + u32 ecx; + u32 dummy; + + if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx, + &dummy, &dummy)) + return (eax >> 8) & 0xff; + *event = ebx; + if (apm_info.connection_version < 0x0102) + *info = ~0; /* indicate info not valid */ + else + *info = ecx; + return APM_SUCCESS; +} + +/** + * set_power_state - set the power management state + * @what: which items to transition + * @state: state to transition to + * + * Request an APM change of state for one or more system devices. The + * processor state must be transitioned last of all. what holds the + * class of device in the upper byte and the device number (0xFF for + * all) for the object to be transitioned. + * + * The state holds the state to transition to, which may in fact + * be an acceptance of a BIOS requested state change. + */ + +static int set_power_state(u_short what, u_short state) +{ + u32 eax; + + if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax)) + return (eax >> 8) & 0xff; + return APM_SUCCESS; +} + +/** + * set_system_power_state - set system wide power state + * @state: which state to enter + * + * Transition the entire system into a new APM power state. + */ + +static int set_system_power_state(u_short state) +{ + return set_power_state(APM_DEVICE_ALL, state); +} + +/** + * apm_do_idle - perform power saving + * + * This function notifies the BIOS that the processor is (in the view + * of the OS) idle. It returns -1 in the event that the BIOS refuses + * to handle the idle request. On a success the function returns 1 + * if the BIOS did clock slowing or 0 otherwise. + */ + +static int apm_do_idle(void) +{ + u32 eax; + u8 ret = 0; + int idled = 0; + int polling; + + polling = !!(current_thread_info()->status & TS_POLLING); + if (polling) { + current_thread_info()->status &= ~TS_POLLING; + /* + * TS_POLLING-cleared state must be visible before we + * test NEED_RESCHED: + */ + smp_mb(); + } + if (!need_resched()) { + idled = 1; + ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax); + } + if (polling) + current_thread_info()->status |= TS_POLLING; + + if (!idled) + return 0; + + if (ret) { + static unsigned long t; + + /* This always fails on some SMP boards running UP kernels. + * Only report the failure the first 5 times. + */ + if (++t < 5) + { + printk(KERN_DEBUG "apm_do_idle failed (%d)\n", + (eax >> 8) & 0xff); + t = jiffies; + } + return -1; + } + clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0; + return clock_slowed; +} + +/** + * apm_do_busy - inform the BIOS the CPU is busy + * + * Request that the BIOS brings the CPU back to full performance. + */ + +static void apm_do_busy(void) +{ + u32 dummy; + + if (clock_slowed || ALWAYS_CALL_BUSY) { + (void) apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy); + clock_slowed = 0; + } +} + +/* + * If no process has really been interested in + * the CPU for some time, we want to call BIOS + * power management - we probably want + * to conserve power. + */ +#define IDLE_CALC_LIMIT (HZ * 100) +#define IDLE_LEAKY_MAX 16 + +static void (*original_pm_idle)(void) __read_mostly; + +/** + * apm_cpu_idle - cpu idling for APM capable Linux + * + * This is the idling function the kernel executes when APM is available. It + * tries to do BIOS powermanagement based on the average system idle time. + * Furthermore it calls the system default idle routine. + */ + +static void apm_cpu_idle(void) +{ + static int use_apm_idle; /* = 0 */ + static unsigned int last_jiffies; /* = 0 */ + static unsigned int last_stime; /* = 0 */ + + int apm_idle_done = 0; + unsigned int jiffies_since_last_check = jiffies - last_jiffies; + unsigned int bucket; + +recalc: + if (jiffies_since_last_check > IDLE_CALC_LIMIT) { + use_apm_idle = 0; + last_jiffies = jiffies; + last_stime = current->stime; + } else if (jiffies_since_last_check > idle_period) { + unsigned int idle_percentage; + + idle_percentage = current->stime - last_stime; + idle_percentage *= 100; + idle_percentage /= jiffies_since_last_check; + use_apm_idle = (idle_percentage > idle_threshold); + if (apm_info.forbid_idle) + use_apm_idle = 0; + last_jiffies = jiffies; + last_stime = current->stime; + } + + bucket = IDLE_LEAKY_MAX; + + while (!need_resched()) { + if (use_apm_idle) { + unsigned int t; + + t = jiffies; + switch (apm_do_idle()) { + case 0: apm_idle_done = 1; + if (t != jiffies) { + if (bucket) { + bucket = IDLE_LEAKY_MAX; + continue; + } + } else if (bucket) { + bucket--; + continue; + } + break; + case 1: apm_idle_done = 1; + break; + default: /* BIOS refused */ + break; + } + } + if (original_pm_idle) + original_pm_idle(); + else + default_idle(); + jiffies_since_last_check = jiffies - last_jiffies; + if (jiffies_since_last_check > idle_period) + goto recalc; + } + + if (apm_idle_done) + apm_do_busy(); +} + +/** + * apm_power_off - ask the BIOS to power off + * + * Handle the power off sequence. This is the one piece of code we + * will execute even on SMP machines. In order to deal with BIOS + * bugs we support real mode APM BIOS power off calls. We also make + * the SMP call on CPU0 as some systems will only honour this call + * on their first cpu. + */ + +static void apm_power_off(void) +{ + unsigned char po_bios_call[] = { + 0xb8, 0x00, 0x10, /* movw $0x1000,ax */ + 0x8e, 0xd0, /* movw ax,ss */ + 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */ + 0xb8, 0x07, 0x53, /* movw $0x5307,ax */ + 0xbb, 0x01, 0x00, /* movw $0x0001,bx */ + 0xb9, 0x03, 0x00, /* movw $0x0003,cx */ + 0xcd, 0x15 /* int $0x15 */ + }; + + /* Some bioses don't like being called from CPU != 0 */ + if (apm_info.realmode_power_off) + { + (void)apm_save_cpus(); + machine_real_restart(po_bios_call, sizeof(po_bios_call)); + } + else + (void) set_system_power_state(APM_STATE_OFF); +} + +#ifdef CONFIG_APM_DO_ENABLE + +/** + * apm_enable_power_management - enable BIOS APM power management + * @enable: enable yes/no + * + * Enable or disable the APM BIOS power services. + */ + +static int apm_enable_power_management(int enable) +{ + u32 eax; + + if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED)) + return APM_NOT_ENGAGED; + if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL, + enable, &eax)) + return (eax >> 8) & 0xff; + if (enable) + apm_info.bios.flags &= ~APM_BIOS_DISABLED; + else + apm_info.bios.flags |= APM_BIOS_DISABLED; + return APM_SUCCESS; +} +#endif + +/** + * apm_get_power_status - get current power state + * @status: returned status + * @bat: battery info + * @life: estimated life + * + * Obtain the current power status from the APM BIOS. We return a + * status which gives the rough battery status, and current power + * source. The bat value returned give an estimate as a percentage + * of life and a status value for the battery. The estimated life + * if reported is a lifetime in secodnds/minutes at current powwer + * consumption. + */ + +static int apm_get_power_status(u_short *status, u_short *bat, u_short *life) +{ + u32 eax; + u32 ebx; + u32 ecx; + u32 edx; + u32 dummy; + + if (apm_info.get_power_status_broken) + return APM_32_UNSUPPORTED; + if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0, + &eax, &ebx, &ecx, &edx, &dummy)) + return (eax >> 8) & 0xff; + *status = ebx; + *bat = ecx; + if (apm_info.get_power_status_swabinminutes) { + *life = swab16((u16)edx); + *life |= 0x8000; + } else + *life = edx; + return APM_SUCCESS; +} + +#if 0 +static int apm_get_battery_status(u_short which, u_short *status, + u_short *bat, u_short *life, u_short *nbat) +{ + u32 eax; + u32 ebx; + u32 ecx; + u32 edx; + u32 esi; + + if (apm_info.connection_version < 0x0102) { + /* pretend we only have one battery. */ + if (which != 1) + return APM_BAD_DEVICE; + *nbat = 1; + return apm_get_power_status(status, bat, life); + } + + if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax, + &ebx, &ecx, &edx, &esi)) + return (eax >> 8) & 0xff; + *status = ebx; + *bat = ecx; + *life = edx; + *nbat = esi; + return APM_SUCCESS; +} +#endif + +/** + * apm_engage_power_management - enable PM on a device + * @device: identity of device + * @enable: on/off + * + * Activate or deactive power management on either a specific device + * or the entire system (%APM_DEVICE_ALL). + */ + +static int apm_engage_power_management(u_short device, int enable) +{ + u32 eax; + + if ((enable == 0) && (device == APM_DEVICE_ALL) + && (apm_info.bios.flags & APM_BIOS_DISABLED)) + return APM_DISABLED; + if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax)) + return (eax >> 8) & 0xff; + if (device == APM_DEVICE_ALL) { + if (enable) + apm_info.bios.flags &= ~APM_BIOS_DISENGAGED; + else + apm_info.bios.flags |= APM_BIOS_DISENGAGED; + } + return APM_SUCCESS; +} + +#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT) + +/** + * apm_console_blank - blank the display + * @blank: on/off + * + * Attempt to blank the console, firstly by blanking just video device + * zero, and if that fails (some BIOSes don't support it) then it blanks + * all video devices. Typically the BIOS will do laptop backlight and + * monitor powerdown for us. + */ + +static int apm_console_blank(int blank) +{ + int error = APM_NOT_ENGAGED; /* silence gcc */ + int i; + u_short state; + static const u_short dev[3] = { 0x100, 0x1FF, 0x101 }; + + state = blank ? APM_STATE_STANDBY : APM_STATE_READY; |