x86, fixmap: define reserve_top_address for x86_64

Impact: new interface (not yet use)

Define reserve_top_address for x86_64; only for later x86 integration.

Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Acked-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Gustavo F. Padovan 2009-02-15 21:48:54 -03:00 committed by H. Peter Anvin
parent ab93e3c45d
commit fd862dde18
3 changed files with 20 additions and 16 deletions

View file

@ -68,6 +68,8 @@ enum fixed_addresses {
__end_of_fixed_addresses
};
extern void reserve_top_address(unsigned long reserve);
#define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)

View file

@ -313,6 +313,24 @@ int ptep_clear_flush_young(struct vm_area_struct *vma,
return young;
}
/**
* reserve_top_address - reserves a hole in the top of kernel address space
* @reserve - size of hole to reserve
*
* Can be used to relocate the fixmap area and poke a hole in the top
* of kernel address space to make room for a hypervisor.
*/
void __init reserve_top_address(unsigned long reserve)
{
#ifdef CONFIG_X86_32
BUG_ON(fixmaps_set > 0);
printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
(int)-reserve);
__FIXADDR_TOP = -reserve - PAGE_SIZE;
__VMALLOC_RESERVE += reserve;
#endif
}
int fixmaps_set;
void __native_set_fixmap(enum fixed_addresses idx, pte_t pte)

View file

@ -97,22 +97,6 @@ void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
unsigned long __FIXADDR_TOP = 0xfffff000;
EXPORT_SYMBOL(__FIXADDR_TOP);
/**
* reserve_top_address - reserves a hole in the top of kernel address space
* @reserve - size of hole to reserve
*
* Can be used to relocate the fixmap area and poke a hole in the top
* of kernel address space to make room for a hypervisor.
*/
void __init reserve_top_address(unsigned long reserve)
{
BUG_ON(fixmaps_set > 0);
printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
(int)-reserve);
__FIXADDR_TOP = -reserve - PAGE_SIZE;
__VMALLOC_RESERVE += reserve;
}
/*
* vmalloc=size forces the vmalloc area to be exactly 'size'
* bytes. This can be used to increase (or decrease) the