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Diffstat (limited to 'arch/i386/kernel/apm.c')
-rw-r--r--arch/i386/kernel/apm.c97
1 files changed, 36 insertions, 61 deletions
diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c
index 1e60acbed3c1..2d793d4aef1a 100644
--- a/arch/i386/kernel/apm.c
+++ b/arch/i386/kernel/apm.c
@@ -303,17 +303,6 @@ extern int (*console_blank_hook)(int);
#include "apm.h"
/*
- * Define to make all _set_limit calls use 64k limits. The APM 1.1 BIOS is
- * supposed to provide limit information that it recognizes. Many machines
- * do this correctly, but many others do not restrict themselves to their
- * claimed limit. When this happens, they will cause a segmentation
- * violation in the kernel at boot time. Most BIOS's, however, will
- * respect a 64k limit, so we use that. If you want to be pedantic and
- * hold your BIOS to its claims, then undefine this.
- */
-#define APM_RELAX_SEGMENTS
-
-/*
* 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>
@@ -1075,22 +1064,23 @@ static int apm_engage_power_management(u_short device, int enable)
static int apm_console_blank(int blank)
{
- int error;
- u_short state;
+ int error, i;
+ u_short state;
+ static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
- /* Blank the first display device */
- error = set_power_state(0x100, state);
- if ((error != APM_SUCCESS) && (error != APM_NO_ERROR)) {
- /* try to blank them all instead */
- error = set_power_state(0x1ff, state);
- if ((error != APM_SUCCESS) && (error != APM_NO_ERROR))
- /* try to blank device one instead */
- error = set_power_state(0x101, state);
+
+ for (i = 0; i < ARRAY_SIZE(dev); i++) {
+ error = set_power_state(dev[i], state);
+
+ if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
+ return 1;
+
+ if (error == APM_NOT_ENGAGED)
+ break;
}
- if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
- return 1;
- if (error == APM_NOT_ENGAGED) {
+
+ if (error == APM_NOT_ENGAGED && state != APM_STATE_READY) {
static int tried;
int eng_error;
if (tried++ == 0) {
@@ -2233,8 +2223,8 @@ static struct dmi_system_id __initdata apm_dmi_table[] = {
static int __init apm_init(void)
{
struct proc_dir_entry *apm_proc;
+ struct desc_struct *gdt;
int ret;
- int i;
dmi_check_system(apm_dmi_table);
@@ -2312,45 +2302,30 @@ static int __init apm_init(void)
set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
_set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
+ /*
+ * Set up the long jump entry point to the APM BIOS, which is called
+ * from inline assembly.
+ */
apm_bios_entry.offset = apm_info.bios.offset;
apm_bios_entry.segment = APM_CS;
- for (i = 0; i < NR_CPUS; i++) {
- struct desc_struct *gdt = get_cpu_gdt_table(i);
- set_base(gdt[APM_CS >> 3],
- __va((unsigned long)apm_info.bios.cseg << 4));
- set_base(gdt[APM_CS_16 >> 3],
- __va((unsigned long)apm_info.bios.cseg_16 << 4));
- set_base(gdt[APM_DS >> 3],
- __va((unsigned long)apm_info.bios.dseg << 4));
-#ifndef APM_RELAX_SEGMENTS
- if (apm_info.bios.version == 0x100) {
-#endif
- /* For ASUS motherboard, Award BIOS rev 110 (and others?) */
- _set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 - 1);
- /* For some unknown machine. */
- _set_limit((char *)&gdt[APM_CS_16 >> 3], 64 * 1024 - 1);
- /* For the DEC Hinote Ultra CT475 (and others?) */
- _set_limit((char *)&gdt[APM_DS >> 3], 64 * 1024 - 1);
-#ifndef APM_RELAX_SEGMENTS
- } else {
- _set_limit((char *)&gdt[APM_CS >> 3],
- (apm_info.bios.cseg_len - 1) & 0xffff);
- _set_limit((char *)&gdt[APM_CS_16 >> 3],
- (apm_info.bios.cseg_16_len - 1) & 0xffff);
- _set_limit((char *)&gdt[APM_DS >> 3],
- (apm_info.bios.dseg_len - 1) & 0xffff);
- /* workaround for broken BIOSes */
- if (apm_info.bios.cseg_len <= apm_info.bios.offset)
- _set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 -1);
- if (apm_info.bios.dseg_len <= 0x40) { /* 0x40 * 4kB == 64kB */
- /* for the BIOS that assumes granularity = 1 */
- gdt[APM_DS >> 3].b |= 0x800000;
- printk(KERN_NOTICE "apm: we set the granularity of dseg.\n");
- }
- }
-#endif
- }
+ /*
+ * The APM 1.1 BIOS is supposed to provide limit information that it
+ * recognizes. Many machines do this correctly, but many others do
+ * not restrict themselves to their claimed limit. When this happens,
+ * they will cause a segmentation violation in the kernel at boot time.
+ * Most BIOS's, however, will respect a 64k limit, so we use that.
+ *
+ * Note we only set APM segments on CPU zero, since we pin the APM
+ * code to that CPU.
+ */
+ gdt = get_cpu_gdt_table(0);
+ set_base(gdt[APM_CS >> 3],
+ __va((unsigned long)apm_info.bios.cseg << 4));
+ set_base(gdt[APM_CS_16 >> 3],
+ __va((unsigned long)apm_info.bios.cseg_16 << 4));
+ set_base(gdt[APM_DS >> 3],
+ __va((unsigned long)apm_info.bios.dseg << 4));
apm_proc = create_proc_info_entry("apm", 0, NULL, apm_get_info);
if (apm_proc)