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Diffstat (limited to 'arch/x86/kernel/apm_32.c')
-rw-r--r--arch/x86/kernel/apm_32.c135
1 files changed, 42 insertions, 93 deletions
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index 53a4e2744846..b37ab1095707 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- linux-c -*-
* APM BIOS driver for Linux
* Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
@@ -5,16 +6,6 @@
* 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
@@ -103,7 +94,7 @@
* 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.
+ * Allow more initialisation 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).
@@ -218,7 +209,8 @@
#include <linux/apm_bios.h>
#include <linux/init.h>
#include <linux/time.h>
-#include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/cputime.h>
#include <linux/pm.h>
#include <linux/capability.h>
#include <linux/device.h>
@@ -234,23 +226,19 @@
#include <linux/i8253.h>
#include <linux/cpuidle.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include <asm/desc.h>
#include <asm/olpc.h>
#include <asm/paravirt.h>
#include <asm/reboot.h>
+#include <asm/nospec-branch.h>
+#include <asm/ibt.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
-
-/*
* 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
@@ -378,7 +366,6 @@ static struct cpuidle_driver apm_idle_driver = {
{ /* entry 1 is for APM idle */
.name = "APM",
.desc = "APM idle",
- .flags = CPUIDLE_FLAG_TIME_VALID,
.exit_latency = 250, /* WAG */
.target_residency = 500, /* WAG */
.enter = &apm_cpu_idle
@@ -392,7 +379,7 @@ static struct cpuidle_device apm_cpuidle_device;
/*
* Local variables
*/
-static struct {
+__visible struct {
unsigned long offset;
unsigned short segment;
} apm_bios_entry;
@@ -433,7 +420,7 @@ static DEFINE_MUTEX(apm_mutex);
* This is for buggy BIOS's that refer to (real mode) segment 0x40
* even though they are called in protected mode.
*/
-static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
+static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(DESC_DATA32_BIOS,
(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
static const char driver_version[] = "1.16ac"; /* no spaces */
@@ -606,19 +593,24 @@ static long __apm_bios_call(void *_call)
struct desc_struct save_desc_40;
struct desc_struct *gdt;
struct apm_bios_call *call = _call;
+ u64 ibt;
cpu = get_cpu();
BUG_ON(cpu != 0);
- gdt = get_cpu_gdt_table(cpu);
+ gdt = get_cpu_gdt_rw(cpu);
save_desc_40 = gdt[0x40 / 8];
gdt[0x40 / 8] = bad_bios_desc;
apm_irq_save(flags);
+ firmware_restrict_branch_speculation_start();
+ ibt = ibt_save(true);
APM_DO_SAVE_SEGS;
apm_bios_call_asm(call->func, call->ebx, call->ecx,
&call->eax, &call->ebx, &call->ecx, &call->edx,
&call->esi);
APM_DO_RESTORE_SEGS;
+ ibt_restore(ibt);
+ firmware_restrict_branch_speculation_end();
apm_irq_restore(flags);
gdt[0x40 / 8] = save_desc_40;
put_cpu();
@@ -682,18 +674,23 @@ static long __apm_bios_call_simple(void *_call)
struct desc_struct save_desc_40;
struct desc_struct *gdt;
struct apm_bios_call *call = _call;
+ u64 ibt;
cpu = get_cpu();
BUG_ON(cpu != 0);
- gdt = get_cpu_gdt_table(cpu);
+ gdt = get_cpu_gdt_rw(cpu);
save_desc_40 = gdt[0x40 / 8];
gdt[0x40 / 8] = bad_bios_desc;
apm_irq_save(flags);
+ firmware_restrict_branch_speculation_start();
+ ibt = ibt_save(true);
APM_DO_SAVE_SEGS;
error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
&call->eax);
APM_DO_RESTORE_SEGS;
+ ibt_restore(ibt);
+ firmware_restrict_branch_speculation_end();
apm_irq_restore(flags);
gdt[0x40 / 8] = save_desc_40;
put_cpu();
@@ -770,7 +767,7 @@ static int apm_driver_version(u_short *val)
* 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
+ * that APM 1.2 is in use. If no messages 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)
@@ -841,24 +838,12 @@ static int apm_do_idle(void)
u32 eax;
u8 ret = 0;
int idled = 0;
- int polling;
int err = 0;
- 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, &err);
}
- if (polling)
- current_thread_info()->status |= TS_POLLING;
if (!idled)
return 0;
@@ -918,21 +903,21 @@ static int apm_cpu_idle(struct cpuidle_device *dev,
{
static int use_apm_idle; /* = 0 */
static unsigned int last_jiffies; /* = 0 */
- static unsigned int last_stime; /* = 0 */
- cputime_t stime;
+ static u64 last_stime; /* = 0 */
+ u64 stime, utime;
int apm_idle_done = 0;
unsigned int jiffies_since_last_check = jiffies - last_jiffies;
unsigned int bucket;
recalc:
- task_cputime(current, NULL, &stime);
+ task_cputime(current, &utime, &stime);
if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
use_apm_idle = 0;
} else if (jiffies_since_last_check > idle_period) {
unsigned int idle_percentage;
- idle_percentage = stime - last_stime;
+ idle_percentage = nsecs_to_jiffies(stime - last_stime);
idle_percentage *= 100;
idle_percentage /= jiffies_since_last_check;
use_apm_idle = (idle_percentage > idle_threshold);
@@ -1041,7 +1026,7 @@ static int apm_enable_power_management(int enable)
* 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
+ * if reported is a lifetime in seconds/minutes at current power
* consumption.
*/
@@ -1055,8 +1040,11 @@ static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
if (apm_info.get_power_status_broken)
return APM_32_UNSUPPORTED;
- if (apm_bios_call(&call))
+ if (apm_bios_call(&call)) {
+ if (!call.err)
+ return APM_NO_ERROR;
return call.err;
+ }
*status = call.ebx;
*bat = call.ecx;
if (apm_info.get_power_status_swabinminutes) {
@@ -1067,41 +1055,12 @@ static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
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
+ * Activate or deactivate power management on either a specific device
* or the entire system (%APM_DEVICE_ALL).
*/
@@ -1515,7 +1474,7 @@ static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *
return 0;
}
-static unsigned int do_poll(struct file *fp, poll_table *wait)
+static __poll_t do_poll(struct file *fp, poll_table *wait)
{
struct apm_user *as;
@@ -1524,7 +1483,7 @@ static unsigned int do_poll(struct file *fp, poll_table *wait)
return 0;
poll_wait(fp, &apm_waitqueue, wait);
if (!queue_empty(as))
- return POLLIN | POLLRDNORM;
+ return EPOLLIN | EPOLLRDNORM;
return 0;
}
@@ -1644,6 +1603,7 @@ static int do_open(struct inode *inode, struct file *filp)
return 0;
}
+#ifdef CONFIG_PROC_FS
static int proc_apm_show(struct seq_file *m, void *v)
{
unsigned short bx;
@@ -1723,19 +1683,7 @@ static int proc_apm_show(struct seq_file *m, void *v)
units);
return 0;
}
-
-static int proc_apm_open(struct inode *inode, struct file *file)
-{
- return single_open(file, proc_apm_show, NULL);
-}
-
-static const struct file_operations apm_file_ops = {
- .owner = THIS_MODULE,
- .open = proc_apm_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
+#endif
static int apm(void *unused)
{
@@ -2052,7 +2000,7 @@ static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
return 0;
}
-static struct dmi_system_id __initdata apm_dmi_table[] = {
+static const struct dmi_system_id apm_dmi_table[] __initconst = {
{
print_if_true,
KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
@@ -2280,7 +2228,7 @@ static int __init apm_init(void)
dmi_check_system(apm_dmi_table);
- if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
+ if (apm_info.bios.version == 0 || machine_is_olpc()) {
printk(KERN_INFO "apm: BIOS not found.\n");
return -ENODEV;
}
@@ -2361,7 +2309,7 @@ static int __init apm_init(void)
* Note we only set APM segments on CPU zero, since we pin the APM
* code to that CPU.
*/
- gdt = get_cpu_gdt_table(0);
+ gdt = get_cpu_gdt_rw(0);
set_desc_base(&gdt[APM_CS >> 3],
(unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
set_desc_base(&gdt[APM_CS_16 >> 3],
@@ -2369,7 +2317,7 @@ static int __init apm_init(void)
set_desc_base(&gdt[APM_DS >> 3],
(unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
- proc_create("apm", 0, NULL, &apm_file_ops);
+ proc_create_single("apm", 0, NULL, proc_apm_show);
kapmd_task = kthread_create(apm, NULL, "kapmd");
if (IS_ERR(kapmd_task)) {
@@ -2398,6 +2346,7 @@ static int __init apm_init(void)
if (HZ != 100)
idle_period = (idle_period * HZ) / 100;
if (idle_threshold < 100) {
+ cpuidle_poll_state_init(&apm_idle_driver);
if (!cpuidle_register_driver(&apm_idle_driver))
if (cpuidle_register_device(&apm_cpuidle_device))
cpuidle_unregister_driver(&apm_idle_driver);
@@ -2454,7 +2403,7 @@ MODULE_PARM_DESC(idle_threshold,
"System idle percentage above which to make APM BIOS idle calls");
module_param(idle_period, int, 0444);
MODULE_PARM_DESC(idle_period,
- "Period (in sec/100) over which to caculate the idle percentage");
+ "Period (in sec/100) over which to calculate the idle percentage");
module_param(smp, bool, 0444);
MODULE_PARM_DESC(smp,
"Set this to enable APM use on an SMP platform. Use with caution on older systems");
generated by cgit (git 2.34.1) at 2025-12-25 06:48:04 +0000