arch/x86/include/asm/pgtable-2level.h at v3.9

tjh.dev / kernel
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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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kernel / arch / x86 / include / asm / pgtable-2level.h
at v3.9 111 lines 3.4 kB view raw
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  1#ifndef _ASM_X86_PGTABLE_2LEVEL_H
  2#define _ASM_X86_PGTABLE_2LEVEL_H
  3
  4#define pte_ERROR(e) \
  5	pr_err("%s:%d: bad pte %08lx\n", __FILE__, __LINE__, (e).pte_low)
  6#define pgd_ERROR(e) \
  7	pr_err("%s:%d: bad pgd %08lx\n", __FILE__, __LINE__, pgd_val(e))
  8
  9/*
 10 * Certain architectures need to do special things when PTEs
 11 * within a page table are directly modified.  Thus, the following
 12 * hook is made available.
 13 */
 14static inline void native_set_pte(pte_t *ptep , pte_t pte)
 15{
 16	*ptep = pte;
 17}
 18
 19static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
 20{
 21	*pmdp = pmd;
 22}
 23
 24static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
 25{
 26	native_set_pte(ptep, pte);
 27}
 28
 29static inline void native_pmd_clear(pmd_t *pmdp)
 30{
 31	native_set_pmd(pmdp, __pmd(0));
 32}
 33
 34static inline void native_pte_clear(struct mm_struct *mm,
 35				    unsigned long addr, pte_t *xp)
 36{
 37	*xp = native_make_pte(0);
 38}
 39
 40#ifdef CONFIG_SMP
 41static inline pte_t native_ptep_get_and_clear(pte_t *xp)
 42{
 43	return __pte(xchg(&xp->pte_low, 0));
 44}
 45#else
 46#define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
 47#endif
 48
 49#ifdef CONFIG_SMP
 50static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
 51{
 52	return __pmd(xchg((pmdval_t *)xp, 0));
 53}
 54#else
 55#define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
 56#endif
 57
 58/*
 59 * Bits _PAGE_BIT_PRESENT, _PAGE_BIT_FILE and _PAGE_BIT_PROTNONE are taken,
 60 * split up the 29 bits of offset into this range:
 61 */
 62#define PTE_FILE_MAX_BITS	29
 63#define PTE_FILE_SHIFT1		(_PAGE_BIT_PRESENT + 1)
 64#if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE
 65#define PTE_FILE_SHIFT2		(_PAGE_BIT_FILE + 1)
 66#define PTE_FILE_SHIFT3		(_PAGE_BIT_PROTNONE + 1)
 67#else
 68#define PTE_FILE_SHIFT2		(_PAGE_BIT_PROTNONE + 1)
 69#define PTE_FILE_SHIFT3		(_PAGE_BIT_FILE + 1)
 70#endif
 71#define PTE_FILE_BITS1		(PTE_FILE_SHIFT2 - PTE_FILE_SHIFT1 - 1)
 72#define PTE_FILE_BITS2		(PTE_FILE_SHIFT3 - PTE_FILE_SHIFT2 - 1)
 73
 74#define pte_to_pgoff(pte)						\
 75	((((pte).pte_low >> PTE_FILE_SHIFT1)				\
 76	  & ((1U << PTE_FILE_BITS1) - 1))				\
 77	 + ((((pte).pte_low >> PTE_FILE_SHIFT2)				\
 78	     & ((1U << PTE_FILE_BITS2) - 1)) << PTE_FILE_BITS1)		\
 79	 + (((pte).pte_low >> PTE_FILE_SHIFT3)				\
 80	    << (PTE_FILE_BITS1 + PTE_FILE_BITS2)))
 81
 82#define pgoff_to_pte(off)						\
 83	((pte_t) { .pte_low =						\
 84	 (((off) & ((1U << PTE_FILE_BITS1) - 1)) << PTE_FILE_SHIFT1)	\
 85	 + ((((off) >> PTE_FILE_BITS1) & ((1U << PTE_FILE_BITS2) - 1))	\
 86	    << PTE_FILE_SHIFT2)						\
 87	 + (((off) >> (PTE_FILE_BITS1 + PTE_FILE_BITS2))		\
 88	    << PTE_FILE_SHIFT3)						\
 89	 + _PAGE_FILE })
 90
 91/* Encode and de-code a swap entry */
 92#if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE
 93#define SWP_TYPE_BITS (_PAGE_BIT_FILE - _PAGE_BIT_PRESENT - 1)
 94#define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1)
 95#else
 96#define SWP_TYPE_BITS (_PAGE_BIT_PROTNONE - _PAGE_BIT_PRESENT - 1)
 97#define SWP_OFFSET_SHIFT (_PAGE_BIT_FILE + 1)
 98#endif
 99
100#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
101
102#define __swp_type(x)			(((x).val >> (_PAGE_BIT_PRESENT + 1)) \
103					 & ((1U << SWP_TYPE_BITS) - 1))
104#define __swp_offset(x)			((x).val >> SWP_OFFSET_SHIFT)
105#define __swp_entry(type, offset)	((swp_entry_t) { \
106					 ((type) << (_PAGE_BIT_PRESENT + 1)) \
107					 | ((offset) << SWP_OFFSET_SHIFT) })
108#define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_low })
109#define __swp_entry_to_pte(x)		((pte_t) { .pte = (x).val })
110
111#endif /* _ASM_X86_PGTABLE_2LEVEL_H */
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