aboutsummaryrefslogtreecommitdiffstats
path: root/arch
diff options
context:
space:
mode:
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/apm.c55
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);
303#include "apm.h" 303#include "apm.h"
304 304
305/* 305/*
306 * Define to make all _set_limit calls use 64k limits. The APM 1.1 BIOS is
307 * supposed to provide limit information that it recognizes. Many machines
308 * do this correctly, but many others do not restrict themselves to their
309 * claimed limit. When this happens, they will cause a segmentation
310 * violation in the kernel at boot time. Most BIOS's, however, will
311 * respect a 64k limit, so we use that. If you want to be pedantic and
312 * hold your BIOS to its claims, then undefine this.
313 */
314#define APM_RELAX_SEGMENTS
315
316/*
317 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend. 306 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
318 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by 307 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
319 * David Chen <chen@ctpa04.mit.edu> 308 * David Chen <chen@ctpa04.mit.edu>
@@ -2312,9 +2301,20 @@ static int __init apm_init(void)
2312 set_base(bad_bios_desc, __va((unsigned long)0x40 << 4)); 2301 set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2313 _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4)); 2302 _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2314 2303
2304 /*
2305 * Set up the long jump entry point to the APM BIOS, which is called
2306 * from inline assembly.
2307 */
2315 apm_bios_entry.offset = apm_info.bios.offset; 2308 apm_bios_entry.offset = apm_info.bios.offset;
2316 apm_bios_entry.segment = APM_CS; 2309 apm_bios_entry.segment = APM_CS;
2317 2310
2311 /*
2312 * The APM 1.1 BIOS is supposed to provide limit information that it
2313 * recognizes. Many machines do this correctly, but many others do
2314 * not restrict themselves to their claimed limit. When this happens,
2315 * they will cause a segmentation violation in the kernel at boot time.
2316 * Most BIOS's, however, will respect a 64k limit, so we use that.
2317 */
2318 for (i = 0; i < NR_CPUS; i++) { 2318 for (i = 0; i < NR_CPUS; i++) {
2319 struct desc_struct *gdt = get_cpu_gdt_table(i); 2319 struct desc_struct *gdt = get_cpu_gdt_table(i);
2320 if (!gdt) 2320 if (!gdt)
@@ -2325,33 +2325,12 @@ static int __init apm_init(void)
2325 __va((unsigned long)apm_info.bios.cseg_16 << 4)); 2325 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2326 set_base(gdt[APM_DS >> 3], 2326 set_base(gdt[APM_DS >> 3],
2327 __va((unsigned long)apm_info.bios.dseg << 4)); 2327 __va((unsigned long)apm_info.bios.dseg << 4));
2328#ifndef APM_RELAX_SEGMENTS 2328 /* For ASUS motherboard, Award BIOS rev 110 (and others?) */
2329 if (apm_info.bios.version == 0x100) { 2329 _set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 - 1);
2330#endif 2330 /* For some unknown machine. */
2331 /* For ASUS motherboard, Award BIOS rev 110 (and others?) */ 2331 _set_limit((char *)&gdt[APM_CS_16 >> 3], 64 * 1024 - 1);
2332 _set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 - 1); 2332 /* For the DEC Hinote Ultra CT475 (and others?) */
2333 /* For some unknown machine. */ 2333 _set_limit((char *)&gdt[APM_DS >> 3], 64 * 1024 - 1);
2334 _set_limit((char *)&gdt[APM_CS_16 >> 3], 64 * 1024 - 1);
2335 /* For the DEC Hinote Ultra CT475 (and others?) */
2336 _set_limit((char *)&gdt[APM_DS >> 3], 64 * 1024 - 1);
2337#ifndef APM_RELAX_SEGMENTS
2338 } else {
2339 _set_limit((char *)&gdt[APM_CS >> 3],
2340 (apm_info.bios.cseg_len - 1) & 0xffff);
2341 _set_limit((char *)&gdt[APM_CS_16 >> 3],
2342 (apm_info.bios.cseg_16_len - 1) & 0xffff);
2343 _set_limit((char *)&gdt[APM_DS >> 3],
2344 (apm_info.bios.dseg_len - 1) & 0xffff);
2345 /* workaround for broken BIOSes */
2346 if (apm_info.bios.cseg_len <= apm_info.bios.offset)
2347 _set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 -1);
2348 if (apm_info.bios.dseg_len <= 0x40) { /* 0x40 * 4kB == 64kB */
2349 /* for the BIOS that assumes granularity = 1 */
2350 gdt[APM_DS >> 3].b |= 0x800000;
2351 printk(KERN_NOTICE "apm: we set the granularity of dseg.\n");
2352 }
2353 }
2354#endif
2355 } 2334 }
2356 2335
2357 apm_proc = create_proc_info_entry("apm", 0, NULL, apm_get_info); 2336 apm_proc = create_proc_info_entry("apm", 0, NULL, apm_get_info);