diff options
Diffstat (limited to 'arch/i386/mm/pgtable.c')
| -rw-r--r-- | arch/i386/mm/pgtable.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c index a9f4910a22f..10126e3f817 100644 --- a/arch/i386/mm/pgtable.c +++ b/arch/i386/mm/pgtable.c @@ -12,6 +12,7 @@ #include <linux/slab.h> #include <linux/pagemap.h> #include <linux/spinlock.h> +#include <linux/module.h> #include <asm/system.h> #include <asm/pgtable.h> @@ -139,6 +140,12 @@ void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) __flush_tlb_one(vaddr); } +static int fixmaps; +#ifndef CONFIG_COMPAT_VDSO +unsigned long __FIXADDR_TOP = 0xfffff000; +EXPORT_SYMBOL(__FIXADDR_TOP); +#endif + void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags) { unsigned long address = __fix_to_virt(idx); @@ -148,6 +155,25 @@ void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags) return; } set_pte_pfn(address, phys >> PAGE_SHIFT, flags); + fixmaps++; +} + +/** + * 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 reserve_top_address(unsigned long reserve) +{ + BUG_ON(fixmaps > 0); +#ifdef CONFIG_COMPAT_VDSO + BUG_ON(reserve != 0); +#else + __FIXADDR_TOP = -reserve - PAGE_SIZE; + __VMALLOC_RESERVE += reserve; +#endif } pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) |