linux/include/asm-i386/pgtable-3level.h
Zachary Amsden 8ecb895069 [PATCH] paravirt: fix missing pte update
The function ptep_get_and_clear uses an atomic instruction sequence to get and
clear an active pte.  Rather than add such an atomic operator to all virtual
machine implementations in paravirt-ops, it is easier to support the raw
atomic sequence and use either a trapping writable pagetable approach, or a
post-update notification.  For the post update notification, we require the
pte_update function to be called after the access.  Combine the 2-level and
3-level paging operators into one common function which does the post-update
notification, and rename the actual atomic sequences to raw_ptep_xxx
operators.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07 02:14:09 +01:00

192 lines
5 KiB
C

#ifndef _I386_PGTABLE_3LEVEL_H
#define _I386_PGTABLE_3LEVEL_H
/*
* Intel Physical Address Extension (PAE) Mode - three-level page
* tables on PPro+ CPUs.
*
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
*/
#define pte_ERROR(e) \
printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low)
#define pmd_ERROR(e) \
printk("%s:%d: bad pmd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
#define pgd_ERROR(e) \
printk("%s:%d: bad pgd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
#define pud_none(pud) 0
#define pud_bad(pud) 0
#define pud_present(pud) 1
/*
* Is the pte executable?
*/
static inline int pte_x(pte_t pte)
{
return !(pte_val(pte) & _PAGE_NX);
}
/*
* All present user-pages with !NX bit are user-executable:
*/
static inline int pte_exec(pte_t pte)
{
return pte_user(pte) && pte_x(pte);
}
/*
* All present pages with !NX bit are kernel-executable:
*/
static inline int pte_exec_kernel(pte_t pte)
{
return pte_x(pte);
}
#ifndef CONFIG_PARAVIRT
/* Rules for using set_pte: the pte being assigned *must* be
* either not present or in a state where the hardware will
* not attempt to update the pte. In places where this is
* not possible, use pte_get_and_clear to obtain the old pte
* value and then use set_pte to update it. -ben
*/
static inline void set_pte(pte_t *ptep, pte_t pte)
{
ptep->pte_high = pte.pte_high;
smp_wmb();
ptep->pte_low = pte.pte_low;
}
#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
/*
* Since this is only called on user PTEs, and the page fault handler
* must handle the already racy situation of simultaneous page faults,
* we are justified in merely clearing the PTE present bit, followed
* by a set. The ordering here is important.
*/
static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
{
ptep->pte_low = 0;
smp_wmb();
ptep->pte_high = pte.pte_high;
smp_wmb();
ptep->pte_low = pte.pte_low;
}
#define set_pte_atomic(pteptr,pteval) \
set_64bit((unsigned long long *)(pteptr),pte_val(pteval))
#define set_pmd(pmdptr,pmdval) \
set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval))
#define set_pud(pudptr,pudval) \
(*(pudptr) = (pudval))
/*
* For PTEs and PDEs, we must clear the P-bit first when clearing a page table
* entry, so clear the bottom half first and enforce ordering with a compiler
* barrier.
*/
static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
ptep->pte_low = 0;
smp_wmb();
ptep->pte_high = 0;
}
static inline void pmd_clear(pmd_t *pmd)
{
u32 *tmp = (u32 *)pmd;
*tmp = 0;
smp_wmb();
*(tmp + 1) = 0;
}
#endif
/*
* Pentium-II erratum A13: in PAE mode we explicitly have to flush
* the TLB via cr3 if the top-level pgd is changed...
* We do not let the generic code free and clear pgd entries due to
* this erratum.
*/
static inline void pud_clear (pud_t * pud) { }
#define pud_page(pud) \
((struct page *) __va(pud_val(pud) & PAGE_MASK))
#define pud_page_vaddr(pud) \
((unsigned long) __va(pud_val(pud) & PAGE_MASK))
/* Find an entry in the second-level page table.. */
#define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \
pmd_index(address))
static inline pte_t raw_ptep_get_and_clear(pte_t *ptep)
{
pte_t res;
/* xchg acts as a barrier before the setting of the high bits */
res.pte_low = xchg(&ptep->pte_low, 0);
res.pte_high = ptep->pte_high;
ptep->pte_high = 0;
return res;
}
#define __HAVE_ARCH_PTE_SAME
static inline int pte_same(pte_t a, pte_t b)
{
return a.pte_low == b.pte_low && a.pte_high == b.pte_high;
}
#define pte_page(x) pfn_to_page(pte_pfn(x))
static inline int pte_none(pte_t pte)
{
return !pte.pte_low && !pte.pte_high;
}
static inline unsigned long pte_pfn(pte_t pte)
{
return (pte.pte_low >> PAGE_SHIFT) |
(pte.pte_high << (32 - PAGE_SHIFT));
}
extern unsigned long long __supported_pte_mask;
static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
{
pte_t pte;
pte.pte_high = (page_nr >> (32 - PAGE_SHIFT)) | \
(pgprot_val(pgprot) >> 32);
pte.pte_high &= (__supported_pte_mask >> 32);
pte.pte_low = ((page_nr << PAGE_SHIFT) | pgprot_val(pgprot)) & \
__supported_pte_mask;
return pte;
}
static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
{
return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) | \
pgprot_val(pgprot)) & __supported_pte_mask);
}
/*
* Bits 0, 6 and 7 are taken in the low part of the pte,
* put the 32 bits of offset into the high part.
*/
#define pte_to_pgoff(pte) ((pte).pte_high)
#define pgoff_to_pte(off) ((pte_t) { _PAGE_FILE, (off) })
#define PTE_FILE_MAX_BITS 32
/* Encode and de-code a swap entry */
#define __swp_type(x) (((x).val) & 0x1f)
#define __swp_offset(x) ((x).val >> 5)
#define __swp_entry(type, offset) ((swp_entry_t){(type) | (offset) << 5})
#define __pte_to_swp_entry(pte) ((swp_entry_t){ (pte).pte_high })
#define __swp_entry_to_pte(x) ((pte_t){ 0, (x).val })
#define __pmd_free_tlb(tlb, x) do { } while (0)
#define vmalloc_sync_all() ((void)0)
#endif /* _I386_PGTABLE_3LEVEL_H */