1 /*
2  *  arch/arm/include/asm/pgalloc.h
3  *
4  *  Copyright (C) 2000-2001 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #ifndef _ASMARM_PGALLOC_H
11 #define _ASMARM_PGALLOC_H
12 
13 #include <linux/pagemap.h>
14 
15 #include <asm/domain.h>
16 #include <asm/pgtable-hwdef.h>
17 #include <asm/processor.h>
18 #include <asm/cacheflush.h>
19 #include <asm/tlbflush.h>
20 
21 #define check_pgt_cache()		do { } while (0)
22 
23 #ifdef CONFIG_MMU
24 
25 #define _PAGE_USER_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
26 #define _PAGE_KERNEL_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
27 
28 #ifdef CONFIG_ARM_LPAE
29 
pmd_alloc_one(struct mm_struct * mm,unsigned long addr)30 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
31 {
32 	return (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
33 }
34 
pmd_free(struct mm_struct * mm,pmd_t * pmd)35 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
36 {
37 	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
38 	free_page((unsigned long)pmd);
39 }
40 
pud_populate(struct mm_struct * mm,pud_t * pud,pmd_t * pmd)41 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
42 {
43 	set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
44 }
45 
46 #else	/* !CONFIG_ARM_LPAE */
47 
48 /*
49  * Since we have only two-level page tables, these are trivial
50  */
51 #define pmd_alloc_one(mm,addr)		({ BUG(); ((pmd_t *)2); })
52 #define pmd_free(mm, pmd)		do { } while (0)
53 #define pud_populate(mm,pmd,pte)	BUG()
54 
55 #endif	/* CONFIG_ARM_LPAE */
56 
57 extern pgd_t *pgd_alloc(struct mm_struct *mm);
58 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
59 
60 #define PGALLOC_GFP	(GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO)
61 
clean_pte_table(pte_t * pte)62 static inline void clean_pte_table(pte_t *pte)
63 {
64 	clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
65 }
66 
67 /*
68  * Allocate one PTE table.
69  *
70  * This actually allocates two hardware PTE tables, but we wrap this up
71  * into one table thus:
72  *
73  *  +------------+
74  *  | Linux pt 0 |
75  *  +------------+
76  *  | Linux pt 1 |
77  *  +------------+
78  *  |  h/w pt 0  |
79  *  +------------+
80  *  |  h/w pt 1  |
81  *  +------------+
82  */
83 static inline pte_t *
pte_alloc_one_kernel(struct mm_struct * mm,unsigned long addr)84 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
85 {
86 	pte_t *pte;
87 
88 	pte = (pte_t *)__get_free_page(PGALLOC_GFP);
89 	if (pte)
90 		clean_pte_table(pte);
91 
92 	return pte;
93 }
94 
95 static inline pgtable_t
pte_alloc_one(struct mm_struct * mm,unsigned long addr)96 pte_alloc_one(struct mm_struct *mm, unsigned long addr)
97 {
98 	struct page *pte;
99 
100 #ifdef CONFIG_HIGHPTE
101 	pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
102 #else
103 	pte = alloc_pages(PGALLOC_GFP, 0);
104 #endif
105 	if (pte) {
106 		if (!PageHighMem(pte))
107 			clean_pte_table(page_address(pte));
108 		pgtable_page_ctor(pte);
109 	}
110 
111 	return pte;
112 }
113 
114 /*
115  * Free one PTE table.
116  */
pte_free_kernel(struct mm_struct * mm,pte_t * pte)117 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
118 {
119 	if (pte)
120 		free_page((unsigned long)pte);
121 }
122 
pte_free(struct mm_struct * mm,pgtable_t pte)123 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
124 {
125 	pgtable_page_dtor(pte);
126 	__free_page(pte);
127 }
128 
__pmd_populate(pmd_t * pmdp,phys_addr_t pte,pmdval_t prot)129 static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
130 				  pmdval_t prot)
131 {
132 	pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
133 	pmdp[0] = __pmd(pmdval);
134 #ifndef CONFIG_ARM_LPAE
135 	pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
136 #endif
137 	flush_pmd_entry(pmdp);
138 }
139 
140 /*
141  * Populate the pmdp entry with a pointer to the pte.  This pmd is part
142  * of the mm address space.
143  *
144  * Ensure that we always set both PMD entries.
145  */
146 static inline void
pmd_populate_kernel(struct mm_struct * mm,pmd_t * pmdp,pte_t * ptep)147 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
148 {
149 	/*
150 	 * The pmd must be loaded with the physical address of the PTE table
151 	 */
152 	__pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
153 }
154 
155 static inline void
pmd_populate(struct mm_struct * mm,pmd_t * pmdp,pgtable_t ptep)156 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
157 {
158 	__pmd_populate(pmdp, page_to_phys(ptep), _PAGE_USER_TABLE);
159 }
160 #define pmd_pgtable(pmd) pmd_page(pmd)
161 
162 #endif /* CONFIG_MMU */
163 
164 #endif
165