diff options
Diffstat (limited to 'arch/i386/kernel/apm.c')
| -rw-r--r-- | arch/i386/kernel/apm.c | 55 |
1 files changed, 17 insertions, 38 deletions
diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c index 6c8e483ce9e4..0d2981120cd6 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> @@ -2312,9 +2301,20 @@ 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; + /* + * 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. + */ for (i = 0; i < NR_CPUS; i++) { struct desc_struct *gdt = get_cpu_gdt_table(i); if (!gdt) @@ -2325,33 +2325,12 @@ static int __init apm_init(void) __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 + /* 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); } apm_proc = create_proc_info_entry("apm", 0, NULL, apm_get_info); |