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linux-next/include/asm-i386/pgtable-2level.h
Zachary Amsden d6d861e3c9 [PATCH] paravirt: optimize ptep establish for pae
The ptep_establish macro is only used on user-level PTEs, for P->P mapping
changes.  Since these always happen under protection of the pagetable lock,
the strong synchronization of a 64-bit cmpxchg is not needed, in fact, not
even a lock prefix needs to be used.  We can simply instead clear the P-bit,
followed by a normal set.  The write ordering is still important to avoid the
possibility of the TLB snooping a partially written PTE and getting a bad
mapping installed.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:34 -07:00

72 lines
2.2 KiB
C

#ifndef _I386_PGTABLE_2LEVEL_H
#define _I386_PGTABLE_2LEVEL_H
#include <asm-generic/pgtable-nopmd.h>
#define pte_ERROR(e) \
printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, (e).pte_low)
#define pgd_ERROR(e) \
printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
/*
* Certain architectures need to do special things when PTEs
* within a page table are directly modified. Thus, the following
* hook is made available.
*/
#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
#define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval)
#define set_pte_present(mm,addr,ptep,pteval) set_pte_at(mm,addr,ptep,pteval)
#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define ptep_get_and_clear(mm,addr,xp) __pte(xchg(&(xp)->pte_low, 0))
#define pte_page(x) pfn_to_page(pte_pfn(x))
#define pte_none(x) (!(x).pte_low)
#define pte_pfn(x) ((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
#define pfn_pmd(pfn, prot) __pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
/*
* All present user pages are user-executable:
*/
static inline int pte_exec(pte_t pte)
{
return pte_user(pte);
}
/*
* All present pages are kernel-executable:
*/
static inline int pte_exec_kernel(pte_t pte)
{
return 1;
}
/*
* Bits 0, 6 and 7 are taken, split up the 29 bits of offset
* into this range:
*/
#define PTE_FILE_MAX_BITS 29
#define pte_to_pgoff(pte) \
((((pte).pte_low >> 1) & 0x1f ) + (((pte).pte_low >> 8) << 5 ))
#define pgoff_to_pte(off) \
((pte_t) { (((off) & 0x1f) << 1) + (((off) >> 5) << 8) + _PAGE_FILE })
/* Encode and de-code a swap entry */
#define __swp_type(x) (((x).val >> 1) & 0x1f)
#define __swp_offset(x) ((x).val >> 8)
#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_low })
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
void vmalloc_sync_all(void);
#endif /* _I386_PGTABLE_2LEVEL_H */