xref: /openbmc/linux/arch/powerpc/include/asm/nohash/32/pgalloc.h (revision 4da722ca19f30f7db250db808d1ab1703607a932)
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),
35 			pgtable_gfp_flags(mm, GFP_KERNEL));
36 }
37 
38 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
39 {
40 	kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
41 }
42 
43 /*
44  * We don't have any real pmd's, and this code never triggers because
45  * the pgd will always be present..
46  */
47 /* #define pmd_alloc_one(mm,address)       ({ BUG(); ((pmd_t *)2); }) */
48 #define pmd_free(mm, x) 		do { } while (0)
49 #define __pmd_free_tlb(tlb,x,a)		do { } while (0)
50 /* #define pgd_populate(mm, pmd, pte)      BUG() */
51 
52 #ifndef CONFIG_BOOKE
53 
54 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
55 				       pte_t *pte)
56 {
57 	*pmdp = __pmd(__pa(pte) | _PMD_PRESENT);
58 }
59 
60 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
61 				pgtable_t pte_page)
62 {
63 	*pmdp = __pmd((page_to_pfn(pte_page) << PAGE_SHIFT) | _PMD_PRESENT);
64 }
65 
66 #define pmd_pgtable(pmd) pmd_page(pmd)
67 #else
68 
69 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
70 				       pte_t *pte)
71 {
72 	*pmdp = __pmd((unsigned long)pte | _PMD_PRESENT);
73 }
74 
75 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
76 				pgtable_t pte_page)
77 {
78 	*pmdp = __pmd((unsigned long)lowmem_page_address(pte_page) | _PMD_PRESENT);
79 }
80 
81 #define pmd_pgtable(pmd) pmd_page(pmd)
82 #endif
83 
84 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
85 extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
86 
87 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
88 {
89 	free_page((unsigned long)pte);
90 }
91 
92 static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
93 {
94 	pgtable_page_dtor(ptepage);
95 	__free_page(ptepage);
96 }
97 
98 static inline void pgtable_free(void *table, unsigned index_size)
99 {
100 	if (!index_size) {
101 		free_page((unsigned long)table);
102 	} else {
103 		BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
104 		kmem_cache_free(PGT_CACHE(index_size), table);
105 	}
106 }
107 
108 #define check_pgt_cache()	do { } while (0)
109 
110 #ifdef CONFIG_SMP
111 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
112 				    void *table, int shift)
113 {
114 	unsigned long pgf = (unsigned long)table;
115 	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
116 	pgf |= shift;
117 	tlb_remove_table(tlb, (void *)pgf);
118 }
119 
120 static inline void __tlb_remove_table(void *_table)
121 {
122 	void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
123 	unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
124 
125 	pgtable_free(table, shift);
126 }
127 #else
128 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
129 				    void *table, int shift)
130 {
131 	pgtable_free(table, shift);
132 }
133 #endif
134 
135 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
136 				  unsigned long address)
137 {
138 	tlb_flush_pgtable(tlb, address);
139 	pgtable_page_dtor(table);
140 	pgtable_free_tlb(tlb, page_address(table), 0);
141 }
142 #endif /* _ASM_POWERPC_PGALLOC_32_H */
143