diff options
| author | Zachary Amsden <zach@vmware.com> | 2006-01-06 00:11:58 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-06 08:33:35 -0800 |
| commit | 92f17f0171e864a2cbe448c5b7b473e72a7d27b8 (patch) | |
| tree | 81e13e2cfa3b95da5fde4478a994db760e0101c0 /arch/i386/kernel/apm.c | |
| parent | 2891dcdc4538e8f4ce50c9d1eea457cf2d81fb5b (diff) | |
[PATCH] x86: Apm is on cpu zero only
APM BIOS code has a protective wrapper that runs it only on CPU zero. Thus,
no need to set APM BIOS segments in the GDT for other CPUs.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Acked-by: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/kernel/apm.c')
| -rw-r--r-- | arch/i386/kernel/apm.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c index 45199bb6455..d0b488056cc 100644 --- a/arch/i386/kernel/apm.c +++ b/arch/i386/kernel/apm.c @@ -2222,8 +2222,8 @@ 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); @@ -2314,18 +2314,17 @@ static int __init apm_init(void) * 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. */ - for (i = 0; i < NR_CPUS; i++) { - struct desc_struct *gdt = get_cpu_gdt_table(i); - if (!gdt) - continue; - 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)); - } + 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) |