xref: /linux/arch/powerpc/include/asm/nohash/32/pgalloc.h (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
1 #ifndef _ASM_POWERPC_PGALLOC_32_H
2 #define _ASM_POWERPC_PGALLOC_32_H
3 
4 #include <linux/threads.h>
5 #include <linux/slab.h>
6 
7 /*
8  * Functions that deal with pagetables that could be at any level of
9  * the table need to be passed an "index_size" so they know how to
10  * handle allocation.  For PTE pages (which are linked to a struct
11  * page for now, and drawn from the main get_free_pages() pool), the
12  * allocation size will be (2^index_size * sizeof(pointer)) and
13  * allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
14  *
15  * The maximum index size needs to be big enough to allow any
16  * pagetable sizes we need, but small enough to fit in the low bits of
17  * any page table pointer.  In other words all pagetables, even tiny
18  * ones, must be aligned to allow at least enough low 0 bits to
19  * contain this value.  This value is also used as a mask, so it must
20  * be one less than a power of two.
21  */
22 #define MAX_PGTABLE_INDEX_SIZE	0xf
23 
24 extern void __bad_pte(pmd_t *pmd);
25 
26 extern struct kmem_cache *pgtable_cache[];
27 #define PGT_CACHE(shift) ({				\
28 			BUG_ON(!(shift));		\
29 			pgtable_cache[(shift) - 1];	\
30 		})
31 
32 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
33 {
34 	return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE), GFP_KERNEL);
35 }
36 
37 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
38 {
39 	kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
40 }
41 
42 /*
43  * We don't have any real pmd's, and this code never triggers because
44  * the pgd will always be present..
45  */
46 /* #define pmd_alloc_one(mm,address)       ({ BUG(); ((pmd_t *)2); }) */
47 #define pmd_free(mm, x) 		do { } while (0)
48 #define __pmd_free_tlb(tlb,x,a)		do { } while (0)
49 /* #define pgd_populate(mm, pmd, pte)      BUG() */
50 
51 #ifndef CONFIG_BOOKE
52 
53 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
54 				       pte_t *pte)
55 {
56 	*pmdp = __pmd(__pa(pte) | _PMD_PRESENT);
57 }
58 
59 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
60 				pgtable_t pte_page)
61 {
62 	*pmdp = __pmd((page_to_pfn(pte_page) << PAGE_SHIFT) | _PMD_PRESENT);
63 }
64 
65 #define pmd_pgtable(pmd) pmd_page(pmd)
66 #else
67 
68 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
69 				       pte_t *pte)
70 {
71 	*pmdp = __pmd((unsigned long)pte | _PMD_PRESENT);
72 }
73 
74 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
75 				pgtable_t pte_page)
76 {
77 	*pmdp = __pmd((unsigned long)lowmem_page_address(pte_page) | _PMD_PRESENT);
78 }
79 
80 #define pmd_pgtable(pmd) pmd_page(pmd)
81 #endif
82 
83 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
84 extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
85 
86 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
87 {
88 	free_page((unsigned long)pte);
89 }
90 
91 static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
92 {
93 	pgtable_page_dtor(ptepage);
94 	__free_page(ptepage);
95 }
96 
97 static inline void pgtable_free(void *table, unsigned index_size)
98 {
99 	if (!index_size) {
100 		free_page((unsigned long)table);
101 	} else {
102 		BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
103 		kmem_cache_free(PGT_CACHE(index_size), table);
104 	}
105 }
106 
107 #define check_pgt_cache()	do { } while (0)
108 
109 #ifdef CONFIG_SMP
110 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
111 				    void *table, int shift)
112 {
113 	unsigned long pgf = (unsigned long)table;
114 	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
115 	pgf |= shift;
116 	tlb_remove_table(tlb, (void *)pgf);
117 }
118 
119 static inline void __tlb_remove_table(void *_table)
120 {
121 	void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
122 	unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
123 
124 	pgtable_free(table, shift);
125 }
126 #else
127 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
128 				    void *table, int shift)
129 {
130 	pgtable_free(table, shift);
131 }
132 #endif
133 
134 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
135 				  unsigned long address)
136 {
137 	tlb_flush_pgtable(tlb, address);
138 	pgtable_page_dtor(table);
139 	pgtable_free_tlb(tlb, page_address(table), 0);
140 }
141 #endif /* _ASM_POWERPC_PGALLOC_32_H */
142