1 #ifndef _ASM_POWERPC_BOOK3S_64_PGALLOC_H
2 #define _ASM_POWERPC_BOOK3S_64_PGALLOC_H
3 /*
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 
10 #include <linux/slab.h>
11 #include <linux/cpumask.h>
12 #include <linux/percpu.h>
13 
14 struct vmemmap_backing {
15 	struct vmemmap_backing *list;
16 	unsigned long phys;
17 	unsigned long virt_addr;
18 };
19 extern struct vmemmap_backing *vmemmap_list;
20 
21 /*
22  * Functions that deal with pagetables that could be at any level of
23  * the table need to be passed an "index_size" so they know how to
24  * handle allocation.  For PTE pages (which are linked to a struct
25  * page for now, and drawn from the main get_free_pages() pool), the
26  * allocation size will be (2^index_size * sizeof(pointer)) and
27  * allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
28  *
29  * The maximum index size needs to be big enough to allow any
30  * pagetable sizes we need, but small enough to fit in the low bits of
31  * any page table pointer.  In other words all pagetables, even tiny
32  * ones, must be aligned to allow at least enough low 0 bits to
33  * contain this value.  This value is also used as a mask, so it must
34  * be one less than a power of two.
35  */
36 #define MAX_PGTABLE_INDEX_SIZE	0xf
37 
38 extern struct kmem_cache *pgtable_cache[];
39 #define PGT_CACHE(shift) ({				\
40 			BUG_ON(!(shift));		\
41 			pgtable_cache[(shift) - 1];	\
42 		})
43 
44 extern pte_t *pte_fragment_alloc(struct mm_struct *, unsigned long, int);
45 extern pmd_t *pmd_fragment_alloc(struct mm_struct *, unsigned long);
46 extern void pte_fragment_free(unsigned long *, int);
47 extern void pmd_fragment_free(unsigned long *);
48 extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift);
49 #ifdef CONFIG_SMP
50 extern void __tlb_remove_table(void *_table);
51 #endif
52 
53 static inline pgd_t *radix__pgd_alloc(struct mm_struct *mm)
54 {
55 #ifdef CONFIG_PPC_64K_PAGES
56 	return (pgd_t *)__get_free_page(pgtable_gfp_flags(mm, PGALLOC_GFP));
57 #else
58 	struct page *page;
59 	page = alloc_pages(pgtable_gfp_flags(mm, PGALLOC_GFP | __GFP_RETRY_MAYFAIL),
60 				4);
61 	if (!page)
62 		return NULL;
63 	return (pgd_t *) page_address(page);
64 #endif
65 }
66 
67 static inline void radix__pgd_free(struct mm_struct *mm, pgd_t *pgd)
68 {
69 #ifdef CONFIG_PPC_64K_PAGES
70 	free_page((unsigned long)pgd);
71 #else
72 	free_pages((unsigned long)pgd, 4);
73 #endif
74 }
75 
76 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
77 {
78 	pgd_t *pgd;
79 
80 	if (radix_enabled())
81 		return radix__pgd_alloc(mm);
82 
83 	pgd = kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
84 			       pgtable_gfp_flags(mm, GFP_KERNEL));
85 	/*
86 	 * With hugetlb, we don't clear the second half of the page table.
87 	 * If we share the same slab cache with the pmd or pud level table,
88 	 * we need to make sure we zero out the full table on alloc.
89 	 * With 4K we don't store slot in the second half. Hence we don't
90 	 * need to do this for 4k.
91 	 */
92 #if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_PPC_64K_PAGES) && \
93 	(H_PGD_INDEX_SIZE == H_PUD_CACHE_INDEX)
94 	memset(pgd, 0, PGD_TABLE_SIZE);
95 #endif
96 	return pgd;
97 }
98 
99 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
100 {
101 	if (radix_enabled())
102 		return radix__pgd_free(mm, pgd);
103 	kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
104 }
105 
106 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
107 {
108 	pgd_set(pgd, __pgtable_ptr_val(pud) | PGD_VAL_BITS);
109 }
110 
111 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
112 {
113 	return kmem_cache_alloc(PGT_CACHE(PUD_CACHE_INDEX),
114 		pgtable_gfp_flags(mm, GFP_KERNEL));
115 }
116 
117 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
118 {
119 	kmem_cache_free(PGT_CACHE(PUD_CACHE_INDEX), pud);
120 }
121 
122 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
123 {
124 	pud_set(pud, __pgtable_ptr_val(pmd) | PUD_VAL_BITS);
125 }
126 
127 static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
128 				  unsigned long address)
129 {
130 	/*
131 	 * By now all the pud entries should be none entries. So go
132 	 * ahead and flush the page walk cache
133 	 */
134 	flush_tlb_pgtable(tlb, address);
135 	pgtable_free_tlb(tlb, pud, PUD_INDEX);
136 }
137 
138 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
139 {
140 	return pmd_fragment_alloc(mm, addr);
141 }
142 
143 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
144 {
145 	pmd_fragment_free((unsigned long *)pmd);
146 }
147 
148 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
149 				  unsigned long address)
150 {
151 	/*
152 	 * By now all the pud entries should be none entries. So go
153 	 * ahead and flush the page walk cache
154 	 */
155 	flush_tlb_pgtable(tlb, address);
156 	return pgtable_free_tlb(tlb, pmd, PMD_INDEX);
157 }
158 
159 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
160 				       pte_t *pte)
161 {
162 	pmd_set(pmd, __pgtable_ptr_val(pte) | PMD_VAL_BITS);
163 }
164 
165 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
166 				pgtable_t pte_page)
167 {
168 	pmd_set(pmd, __pgtable_ptr_val(pte_page) | PMD_VAL_BITS);
169 }
170 
171 static inline pgtable_t pmd_pgtable(pmd_t pmd)
172 {
173 	return (pgtable_t)pmd_page_vaddr(pmd);
174 }
175 
176 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
177 					  unsigned long address)
178 {
179 	return (pte_t *)pte_fragment_alloc(mm, address, 1);
180 }
181 
182 static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
183 				      unsigned long address)
184 {
185 	return (pgtable_t)pte_fragment_alloc(mm, address, 0);
186 }
187 
188 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
189 {
190 	pte_fragment_free((unsigned long *)pte, 1);
191 }
192 
193 static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
194 {
195 	pte_fragment_free((unsigned long *)ptepage, 0);
196 }
197 
198 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
199 				  unsigned long address)
200 {
201 	/*
202 	 * By now all the pud entries should be none entries. So go
203 	 * ahead and flush the page walk cache
204 	 */
205 	flush_tlb_pgtable(tlb, address);
206 	pgtable_free_tlb(tlb, table, PTE_INDEX);
207 }
208 
209 #define check_pgt_cache()	do { } while (0)
210 
211 #endif /* _ASM_POWERPC_BOOK3S_64_PGALLOC_H */
212