1#ifndef _I386_PGTABLE_3LEVEL_H
2#define _I386_PGTABLE_3LEVEL_H
3
4/*
5 * Intel Physical Address Extension (PAE) Mode - three-level page
6 * tables on PPro+ CPUs.
7 *
8 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
9 */
10
11#define pte_ERROR(e) \
12	printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low)
13#define pmd_ERROR(e) \
14	printk("%s:%d: bad pmd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
15#define pgd_ERROR(e) \
16	printk("%s:%d: bad pgd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
17
18#define pud_none(pud)				0
19#define pud_bad(pud)				0
20#define pud_present(pud)			1
21
22/*
23 * Is the pte executable?
24 */
25static inline int pte_x(pte_t pte)
26{
27	return !(pte_val(pte) & _PAGE_NX);
28}
29
30/*
31 * All present user-pages with !NX bit are user-executable:
32 */
33static inline int pte_exec(pte_t pte)
34{
35	return pte_user(pte) && pte_x(pte);
36}
37/*
38 * All present pages with !NX bit are kernel-executable:
39 */
40static inline int pte_exec_kernel(pte_t pte)
41{
42	return pte_x(pte);
43}
44
45/* Rules for using set_pte: the pte being assigned *must* be
46 * either not present or in a state where the hardware will
47 * not attempt to update the pte.  In places where this is
48 * not possible, use pte_get_and_clear to obtain the old pte
49 * value and then use set_pte to update it.  -ben
50 */
51static inline void native_set_pte(pte_t *ptep, pte_t pte)
52{
53	ptep->pte_high = pte.pte_high;
54	smp_wmb();
55	ptep->pte_low = pte.pte_low;
56}
57static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
58				     pte_t *ptep , pte_t pte)
59{
60	native_set_pte(ptep, pte);
61}
62
63/*
64 * Since this is only called on user PTEs, and the page fault handler
65 * must handle the already racy situation of simultaneous page faults,
66 * we are justified in merely clearing the PTE present bit, followed
67 * by a set.  The ordering here is important.
68 */
69static inline void native_set_pte_present(struct mm_struct *mm, unsigned long addr,
70					  pte_t *ptep, pte_t pte)
71{
72	ptep->pte_low = 0;
73	smp_wmb();
74	ptep->pte_high = pte.pte_high;
75	smp_wmb();
76	ptep->pte_low = pte.pte_low;
77}
78
79static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
80{
81	set_64bit((unsigned long long *)(ptep),native_pte_val(pte));
82}
83static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
84{
85	set_64bit((unsigned long long *)(pmdp),native_pmd_val(pmd));
86}
87static inline void native_set_pud(pud_t *pudp, pud_t pud)
88{
89	*pudp = pud;
90}
91
92/*
93 * For PTEs and PDEs, we must clear the P-bit first when clearing a page table
94 * entry, so clear the bottom half first and enforce ordering with a compiler
95 * barrier.
96 */
97static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
98{
99	ptep->pte_low = 0;
100	smp_wmb();
101	ptep->pte_high = 0;
102}
103
104static inline void native_pmd_clear(pmd_t *pmd)
105{
106	u32 *tmp = (u32 *)pmd;
107	*tmp = 0;
108	smp_wmb();
109	*(tmp + 1) = 0;
110}
111
112#ifndef CONFIG_PARAVIRT
113#define set_pte(ptep, pte)			native_set_pte(ptep, pte)
114#define set_pte_at(mm, addr, ptep, pte)		native_set_pte_at(mm, addr, ptep, pte)
115#define set_pte_present(mm, addr, ptep, pte)	native_set_pte_present(mm, addr, ptep, pte)
116#define set_pte_atomic(ptep, pte)		native_set_pte_atomic(ptep, pte)
117#define set_pmd(pmdp, pmd)			native_set_pmd(pmdp, pmd)
118#define set_pud(pudp, pud)			native_set_pud(pudp, pud)
119#define pte_clear(mm, addr, ptep)		native_pte_clear(mm, addr, ptep)
120#define pmd_clear(pmd)				native_pmd_clear(pmd)
121#endif
122
123/*
124 * Pentium-II erratum A13: in PAE mode we explicitly have to flush
125 * the TLB via cr3 if the top-level pgd is changed...
126 * We do not let the generic code free and clear pgd entries due to
127 * this erratum.
128 */
129static inline void pud_clear (pud_t * pud) { }
130
131#define pud_page(pud) \
132((struct page *) __va(pud_val(pud) & PAGE_MASK))
133
134#define pud_page_vaddr(pud) \
135((unsigned long) __va(pud_val(pud) & PAGE_MASK))
136
137
138/* Find an entry in the second-level page table.. */
139#define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \
140			pmd_index(address))
141
142#ifdef CONFIG_SMP
143static inline pte_t native_ptep_get_and_clear(pte_t *ptep)
144{
145	pte_t res;
146
147	/* xchg acts as a barrier before the setting of the high bits */
148	res.pte_low = xchg(&ptep->pte_low, 0);
149	res.pte_high = ptep->pte_high;
150	ptep->pte_high = 0;
151
152	return res;
153}
154#else
155#define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
156#endif
157
158#define __HAVE_ARCH_PTE_SAME
159static inline int pte_same(pte_t a, pte_t b)
160{
161	return a.pte_low == b.pte_low && a.pte_high == b.pte_high;
162}
163
164#define pte_page(x)	pfn_to_page(pte_pfn(x))
165
166static inline int pte_none(pte_t pte)
167{
168	return !pte.pte_low && !pte.pte_high;
169}
170
171static inline unsigned long pte_pfn(pte_t pte)
172{
173	return pte_val(pte) >> PAGE_SHIFT;
174}
175
176extern unsigned long long __supported_pte_mask;
177
178static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
179{
180	return __pte((((unsigned long long)page_nr << PAGE_SHIFT) |
181		      pgprot_val(pgprot)) & __supported_pte_mask);
182}
183
184static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
185{
186	return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) |
187		      pgprot_val(pgprot)) & __supported_pte_mask);
188}
189
190/*
191 * Bits 0, 6 and 7 are taken in the low part of the pte,
192 * put the 32 bits of offset into the high part.
193 */
194#define pte_to_pgoff(pte) ((pte).pte_high)
195#define pgoff_to_pte(off) ((pte_t) { _PAGE_FILE, (off) })
196#define PTE_FILE_MAX_BITS       32
197
198/* Encode and de-code a swap entry */
199#define __swp_type(x)			(((x).val) & 0x1f)
200#define __swp_offset(x)			((x).val >> 5)
201#define __swp_entry(type, offset)	((swp_entry_t){(type) | (offset) << 5})
202#define __pte_to_swp_entry(pte)		((swp_entry_t){ (pte).pte_high })
203#define __swp_entry_to_pte(x)		((pte_t){ 0, (x).val })
204
205#define __pmd_free_tlb(tlb, x)		do { } while (0)
206
207#endif /* _I386_PGTABLE_3LEVEL_H */
208