1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_PGALLOC_32_H
3 #define _ASM_POWERPC_PGALLOC_32_H
4 
5 #include <linux/threads.h>
6 #include <linux/slab.h>
7 
8 /*
9  * Functions that deal with pagetables that could be at any level of
10  * the table need to be passed an "index_size" so they know how to
11  * handle allocation.  For PTE pages (which are linked to a struct
12  * page for now, and drawn from the main get_free_pages() pool), the
13  * allocation size will be (2^index_size * sizeof(pointer)) and
14  * allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
15  *
16  * The maximum index size needs to be big enough to allow any
17  * pagetable sizes we need, but small enough to fit in the low bits of
18  * any page table pointer.  In other words all pagetables, even tiny
19  * ones, must be aligned to allow at least enough low 0 bits to
20  * contain this value.  This value is also used as a mask, so it must
21  * be one less than a power of two.
22  */
23 #define MAX_PGTABLE_INDEX_SIZE	0xf
24 
25 extern void __bad_pte(pmd_t *pmd);
26 
27 extern struct kmem_cache *pgtable_cache[];
28 #define PGT_CACHE(shift) ({				\
29 			BUG_ON(!(shift));		\
30 			pgtable_cache[(shift) - 1];	\
31 		})
32 
33 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
34 {
35 	return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
36 			pgtable_gfp_flags(mm, GFP_KERNEL));
37 }
38 
39 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
40 {
41 	kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
42 }
43 
44 /*
45  * We don't have any real pmd's, and this code never triggers because
46  * the pgd will always be present..
47  */
48 /* #define pmd_alloc_one(mm,address)       ({ BUG(); ((pmd_t *)2); }) */
49 #define pmd_free(mm, x) 		do { } while (0)
50 #define __pmd_free_tlb(tlb,x,a)		do { } while (0)
51 /* #define pgd_populate(mm, pmd, pte)      BUG() */
52 
53 #ifndef CONFIG_BOOKE
54 
55 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
56 				       pte_t *pte)
57 {
58 	*pmdp = __pmd(__pa(pte) | _PMD_PRESENT);
59 }
60 
61 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
62 				pgtable_t pte_page)
63 {
64 	*pmdp = __pmd((page_to_pfn(pte_page) << PAGE_SHIFT) | _PMD_PRESENT);
65 }
66 
67 #define pmd_pgtable(pmd) pmd_page(pmd)
68 #else
69 
70 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
71 				       pte_t *pte)
72 {
73 	*pmdp = __pmd((unsigned long)pte | _PMD_PRESENT);
74 }
75 
76 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
77 				pgtable_t pte_page)
78 {
79 	*pmdp = __pmd((unsigned long)lowmem_page_address(pte_page) | _PMD_PRESENT);
80 }
81 
82 #define pmd_pgtable(pmd) pmd_page(pmd)
83 #endif
84 
85 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
86 extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
87 
88 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
89 {
90 	free_page((unsigned long)pte);
91 }
92 
93 static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
94 {
95 	pgtable_page_dtor(ptepage);
96 	__free_page(ptepage);
97 }
98 
99 static inline void pgtable_free(void *table, unsigned index_size)
100 {
101 	if (!index_size) {
102 		free_page((unsigned long)table);
103 	} else {
104 		BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
105 		kmem_cache_free(PGT_CACHE(index_size), table);
106 	}
107 }
108 
109 #define check_pgt_cache()	do { } while (0)
110 
111 #ifdef CONFIG_SMP
112 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
113 				    void *table, int shift)
114 {
115 	unsigned long pgf = (unsigned long)table;
116 	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
117 	pgf |= shift;
118 	tlb_remove_table(tlb, (void *)pgf);
119 }
120 
121 static inline void __tlb_remove_table(void *_table)
122 {
123 	void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
124 	unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
125 
126 	pgtable_free(table, shift);
127 }
128 #else
129 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
130 				    void *table, int shift)
131 {
132 	pgtable_free(table, shift);
133 }
134 #endif
135 
136 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
137 				  unsigned long address)
138 {
139 	tlb_flush_pgtable(tlb, address);
140 	pgtable_page_dtor(table);
141 	pgtable_free_tlb(tlb, page_address(table), 0);
142 }
143 #endif /* _ASM_POWERPC_PGALLOC_32_H */
144