2 * linux/arch/i386/kernel/sysenter.c
4 * (C) Copyright 2002 Linus Torvalds
6 * This file contains the needed initializations to support sysenter.
9 #include <linux/init.h>
10 #include <linux/smp.h>
11 #include <linux/thread_info.h>
12 #include <linux/sched.h>
13 #include <linux/gfp.h>
14 #include <linux/string.h>
15 #include <linux/elf.h>
17 #include <asm/cpufeature.h>
19 #include <asm/pgtable.h>
20 #include <asm/unistd.h>
22 extern asmlinkage
void sysenter_entry(void);
24 void enable_sep_cpu(void)
27 struct tss_struct
*tss
= &per_cpu(init_tss
, cpu
);
29 if (!boot_cpu_has(X86_FEATURE_SEP
)) {
34 tss
->ss1
= __KERNEL_CS
;
35 tss
->esp1
= sizeof(struct tss_struct
) + (unsigned long) tss
;
36 wrmsr(MSR_IA32_SYSENTER_CS
, __KERNEL_CS
, 0);
37 wrmsr(MSR_IA32_SYSENTER_ESP
, tss
->esp1
, 0);
38 wrmsr(MSR_IA32_SYSENTER_EIP
, (unsigned long) sysenter_entry
, 0);
43 * These symbols are defined by vsyscall.o to mark the bounds
44 * of the ELF DSO images included therein.
46 extern const char vsyscall_int80_start
, vsyscall_int80_end
;
47 extern const char vsyscall_sysenter_start
, vsyscall_sysenter_end
;
49 int __init
sysenter_setup(void)
51 void *page
= (void *)get_zeroed_page(GFP_ATOMIC
);
53 __set_fixmap(FIX_VSYSCALL
, __pa(page
), PAGE_READONLY_EXEC
);
55 if (!boot_cpu_has(X86_FEATURE_SEP
)) {
57 &vsyscall_int80_start
,
58 &vsyscall_int80_end
- &vsyscall_int80_start
);
63 &vsyscall_sysenter_start
,
64 &vsyscall_sysenter_end
- &vsyscall_sysenter_start
);