1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef _ASM_POWERPC_BOOK3S_64_PGALLOC_H
3 #define _ASM_POWERPC_BOOK3S_64_PGALLOC_H
4 /*
5  */
6 
7 #include <linux/slab.h>
8 #include <linux/cpumask.h>
9 #include <linux/kmemleak.h>
10 #include <linux/percpu.h>
11 
12 struct vmemmap_backing {
13 	struct vmemmap_backing *list;
14 	unsigned long phys;
15 	unsigned long virt_addr;
16 };
17 extern struct vmemmap_backing *vmemmap_list;
18 
19 extern pmd_t *pmd_fragment_alloc(struct mm_struct *, unsigned long);
20 extern void pmd_fragment_free(unsigned long *);
21 extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift);
22 extern void __tlb_remove_table(void *_table);
23 void pte_frag_destroy(void *pte_frag);
24 
25 static inline pgd_t *radix__pgd_alloc(struct mm_struct *mm)
26 {
27 #ifdef CONFIG_PPC_64K_PAGES
28 	return (pgd_t *)__get_free_page(pgtable_gfp_flags(mm, PGALLOC_GFP));
29 #else
30 	struct page *page;
31 	page = alloc_pages(pgtable_gfp_flags(mm, PGALLOC_GFP | __GFP_RETRY_MAYFAIL),
32 				4);
33 	if (!page)
34 		return NULL;
35 	return (pgd_t *) page_address(page);
36 #endif
37 }
38 
39 static inline void radix__pgd_free(struct mm_struct *mm, pgd_t *pgd)
40 {
41 #ifdef CONFIG_PPC_64K_PAGES
42 	free_page((unsigned long)pgd);
43 #else
44 	free_pages((unsigned long)pgd, 4);
45 #endif
46 }
47 
48 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
49 {
50 	pgd_t *pgd;
51 
52 	if (radix_enabled())
53 		return radix__pgd_alloc(mm);
54 
55 	pgd = kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
56 			       pgtable_gfp_flags(mm, GFP_KERNEL));
57 	if (unlikely(!pgd))
58 		return pgd;
59 
60 	/*
61 	 * Don't scan the PGD for pointers, it contains references to PUDs but
62 	 * those references are not full pointers and so can't be recognised by
63 	 * kmemleak.
64 	 */
65 	kmemleak_no_scan(pgd);
66 
67 	/*
68 	 * With hugetlb, we don't clear the second half of the page table.
69 	 * If we share the same slab cache with the pmd or pud level table,
70 	 * we need to make sure we zero out the full table on alloc.
71 	 * With 4K we don't store slot in the second half. Hence we don't
72 	 * need to do this for 4k.
73 	 */
74 #if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_PPC_64K_PAGES) && \
75 	(H_PGD_INDEX_SIZE == H_PUD_CACHE_INDEX)
76 	memset(pgd, 0, PGD_TABLE_SIZE);
77 #endif
78 	return pgd;
79 }
80 
81 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
82 {
83 	if (radix_enabled())
84 		return radix__pgd_free(mm, pgd);
85 	kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
86 }
87 
88 static inline void p4d_populate(struct mm_struct *mm, p4d_t *pgd, pud_t *pud)
89 {
90 	*pgd =  __p4d(__pgtable_ptr_val(pud) | PGD_VAL_BITS);
91 }
92 
93 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
94 {
95 	pud_t *pud;
96 
97 	pud = kmem_cache_alloc(PGT_CACHE(PUD_CACHE_INDEX),
98 			       pgtable_gfp_flags(mm, GFP_KERNEL));
99 	/*
100 	 * Tell kmemleak to ignore the PUD, that means don't scan it for
101 	 * pointers and don't consider it a leak. PUDs are typically only
102 	 * referred to by their PGD, but kmemleak is not able to recognise those
103 	 * as pointers, leading to false leak reports.
104 	 */
105 	kmemleak_ignore(pud);
106 
107 	return pud;
108 }
109 
110 static inline void __pud_free(pud_t *pud)
111 {
112 	struct page *page = virt_to_page(pud);
113 
114 	/*
115 	 * Early pud pages allocated via memblock allocator
116 	 * can't be directly freed to slab. KFENCE pages have
117 	 * both reserved and slab flags set so need to be freed
118 	 * kmem_cache_free.
119 	 */
120 	if (PageReserved(page) && !PageSlab(page))
121 		free_reserved_page(page);
122 	else
123 		kmem_cache_free(PGT_CACHE(PUD_CACHE_INDEX), pud);
124 }
125 
126 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
127 {
128 	return __pud_free(pud);
129 }
130 
131 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
132 {
133 	*pud = __pud(__pgtable_ptr_val(pmd) | PUD_VAL_BITS);
134 }
135 
136 static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
137 				  unsigned long address)
138 {
139 	pgtable_free_tlb(tlb, pud, PUD_INDEX);
140 }
141 
142 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
143 {
144 	return pmd_fragment_alloc(mm, addr);
145 }
146 
147 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
148 {
149 	pmd_fragment_free((unsigned long *)pmd);
150 }
151 
152 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
153 				  unsigned long address)
154 {
155 	return pgtable_free_tlb(tlb, pmd, PMD_INDEX);
156 }
157 
158 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
159 				       pte_t *pte)
160 {
161 	*pmd = __pmd(__pgtable_ptr_val(pte) | PMD_VAL_BITS);
162 }
163 
164 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
165 				pgtable_t pte_page)
166 {
167 	*pmd = __pmd(__pgtable_ptr_val(pte_page) | PMD_VAL_BITS);
168 }
169 
170 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
171 				  unsigned long address)
172 {
173 	pgtable_free_tlb(tlb, table, PTE_INDEX);
174 }
175 
176 extern atomic_long_t direct_pages_count[MMU_PAGE_COUNT];
177 static inline void update_page_count(int psize, long count)
178 {
179 	if (IS_ENABLED(CONFIG_PROC_FS))
180 		atomic_long_add(count, &direct_pages_count[psize]);
181 }
182 
183 #endif /* _ASM_POWERPC_BOOK3S_64_PGALLOC_H */
184