mirror of
https://github.com/torvalds/linux.git
synced 2024-12-27 21:33:00 +00:00
1ad83c858c
This adds CONFIG_X86_VSYSCALL_EMULATION, guarded by CONFIG_EXPERT. Turning it off completely disables vsyscall emulation, saving ~3.5k for vsyscall_64.c, 4k for vsyscall_emu_64.S (the fake vsyscall page), some tiny amount of core mm code that supports a gate area, and possibly 4k for a wasted pagetable. The latter is because the vsyscall addresses are misaligned and fit poorly in the fixmap. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/406db88b8dd5f0cbbf38216d11be34bbb43c7eae.1414618407.git.luto@amacapital.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
47 lines
1.1 KiB
C
47 lines
1.1 KiB
C
#ifndef _ASM_X86_PAGE_64_H
|
|
#define _ASM_X86_PAGE_64_H
|
|
|
|
#include <asm/page_64_types.h>
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
/* duplicated to the one in bootmem.h */
|
|
extern unsigned long max_pfn;
|
|
extern unsigned long phys_base;
|
|
|
|
static inline unsigned long __phys_addr_nodebug(unsigned long x)
|
|
{
|
|
unsigned long y = x - __START_KERNEL_map;
|
|
|
|
/* use the carry flag to determine if x was < __START_KERNEL_map */
|
|
x = y + ((x > y) ? phys_base : (__START_KERNEL_map - PAGE_OFFSET));
|
|
|
|
return x;
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_VIRTUAL
|
|
extern unsigned long __phys_addr(unsigned long);
|
|
extern unsigned long __phys_addr_symbol(unsigned long);
|
|
#else
|
|
#define __phys_addr(x) __phys_addr_nodebug(x)
|
|
#define __phys_addr_symbol(x) \
|
|
((unsigned long)(x) - __START_KERNEL_map + phys_base)
|
|
#endif
|
|
|
|
#define __phys_reloc_hide(x) (x)
|
|
|
|
#ifdef CONFIG_FLATMEM
|
|
#define pfn_valid(pfn) ((pfn) < max_pfn)
|
|
#endif
|
|
|
|
void clear_page(void *page);
|
|
void copy_page(void *to, void *from);
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#ifdef CONFIG_X86_VSYSCALL_EMULATION
|
|
# define __HAVE_ARCH_GATE_AREA 1
|
|
#endif
|
|
|
|
#endif /* _ASM_X86_PAGE_64_H */
|