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)