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_USER |
65 		      _PMD_PRESENT);
66 }
67 
68 #define pmd_pgtable(pmd) pmd_page(pmd)
69 #else
70 
71 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
72 				       pte_t *pte)
73 {
74 	*pmdp = __pmd((unsigned long)pte | _PMD_PRESENT);
75 }
76 
77 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
78 				pgtable_t pte_page)
79 {
80 	*pmdp = __pmd((unsigned long)lowmem_page_address(pte_page) | _PMD_PRESENT);
81 }
82 
83 #define pmd_pgtable(pmd) pmd_page(pmd)
84 #endif
85 
86 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
87 extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
88 
89 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
90 {
91 	free_page((unsigned long)pte);
92 }
93 
94 static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
95 {
96 	pgtable_page_dtor(ptepage);
97 	__free_page(ptepage);
98 }
99 
100 static inline void pgtable_free(void *table, unsigned index_size)
101 {
102 	if (!index_size) {
103 		pgtable_page_dtor(virt_to_page(table));
104 		free_page((unsigned long)table);
105 	} else {
106 		BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
107 		kmem_cache_free(PGT_CACHE(index_size), table);
108 	}
109 }
110 
111 #define check_pgt_cache()	do { } while (0)
112 
113 #ifdef CONFIG_SMP
114 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
115 				    void *table, int shift)
116 {
117 	unsigned long pgf = (unsigned long)table;
118 	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
119 	pgf |= shift;
120 	tlb_remove_table(tlb, (void *)pgf);
121 }
122 
123 static inline void __tlb_remove_table(void *_table)
124 {
125 	void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
126 	unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
127 
128 	pgtable_free(table, shift);
129 }
130 #else
131 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
132 				    void *table, int shift)
133 {
134 	pgtable_free(table, shift);
135 }
136 #endif
137 
138 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
139 				  unsigned long address)
140 {
141 	tlb_flush_pgtable(tlb, address);
142 	pgtable_page_dtor(table);
143 	pgtable_free_tlb(tlb, page_address(table), 0);
144 }
145 #endif /* _ASM_POWERPC_PGALLOC_32_H */
146