Commit | Line | Data |
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736d2169 HD |
1 | /* |
2 | * PARISC64 Huge TLB page support. | |
3 | * | |
4 | * This parisc implementation is heavily based on the SPARC and x86 code. | |
5 | * | |
6 | * Copyright (C) 2015 Helge Deller <deller@gmx.de> | |
7 | */ | |
8 | ||
9 | #include <linux/fs.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/hugetlb.h> | |
12 | #include <linux/pagemap.h> | |
13 | #include <linux/sysctl.h> | |
14 | ||
15 | #include <asm/mman.h> | |
16 | #include <asm/pgalloc.h> | |
17 | #include <asm/tlb.h> | |
18 | #include <asm/tlbflush.h> | |
19 | #include <asm/cacheflush.h> | |
20 | #include <asm/mmu_context.h> | |
21 | ||
22 | ||
23 | unsigned long | |
24 | hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
25 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
26 | { | |
27 | struct hstate *h = hstate_file(file); | |
28 | ||
29 | if (len & ~huge_page_mask(h)) | |
30 | return -EINVAL; | |
31 | if (len > TASK_SIZE) | |
32 | return -ENOMEM; | |
33 | ||
34 | if (flags & MAP_FIXED) | |
35 | if (prepare_hugepage_range(file, addr, len)) | |
36 | return -EINVAL; | |
37 | ||
38 | if (addr) | |
39 | addr = ALIGN(addr, huge_page_size(h)); | |
40 | ||
41 | /* we need to make sure the colouring is OK */ | |
42 | return arch_get_unmapped_area(file, addr, len, pgoff, flags); | |
43 | } | |
44 | ||
45 | ||
46 | pte_t *huge_pte_alloc(struct mm_struct *mm, | |
47 | unsigned long addr, unsigned long sz) | |
48 | { | |
49 | pgd_t *pgd; | |
50 | pud_t *pud; | |
51 | pmd_t *pmd; | |
52 | pte_t *pte = NULL; | |
53 | ||
54 | /* We must align the address, because our caller will run | |
55 | * set_huge_pte_at() on whatever we return, which writes out | |
56 | * all of the sub-ptes for the hugepage range. So we have | |
57 | * to give it the first such sub-pte. | |
58 | */ | |
59 | addr &= HPAGE_MASK; | |
60 | ||
61 | pgd = pgd_offset(mm, addr); | |
62 | pud = pud_alloc(mm, pgd, addr); | |
63 | if (pud) { | |
64 | pmd = pmd_alloc(mm, pud, addr); | |
65 | if (pmd) | |
66 | pte = pte_alloc_map(mm, NULL, pmd, addr); | |
67 | } | |
68 | return pte; | |
69 | } | |
70 | ||
71 | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) | |
72 | { | |
73 | pgd_t *pgd; | |
74 | pud_t *pud; | |
75 | pmd_t *pmd; | |
76 | pte_t *pte = NULL; | |
77 | ||
78 | addr &= HPAGE_MASK; | |
79 | ||
80 | pgd = pgd_offset(mm, addr); | |
81 | if (!pgd_none(*pgd)) { | |
82 | pud = pud_offset(pgd, addr); | |
83 | if (!pud_none(*pud)) { | |
84 | pmd = pmd_offset(pud, addr); | |
85 | if (!pmd_none(*pmd)) | |
86 | pte = pte_offset_map(pmd, addr); | |
87 | } | |
88 | } | |
89 | return pte; | |
90 | } | |
91 | ||
92 | /* Purge data and instruction TLB entries. Must be called holding | |
93 | * the pa_tlb_lock. The TLB purge instructions are slow on SMP | |
94 | * machines since the purge must be broadcast to all CPUs. | |
95 | */ | |
96 | static inline void purge_tlb_entries_huge(struct mm_struct *mm, unsigned long addr) | |
97 | { | |
98 | int i; | |
99 | ||
100 | /* We may use multiple physical huge pages (e.g. 2x1 MB) to emulate | |
101 | * Linux standard huge pages (e.g. 2 MB) */ | |
102 | BUILD_BUG_ON(REAL_HPAGE_SHIFT > HPAGE_SHIFT); | |
103 | ||
104 | addr &= HPAGE_MASK; | |
105 | addr |= _HUGE_PAGE_SIZE_ENCODING_DEFAULT; | |
106 | ||
107 | for (i = 0; i < (1 << (HPAGE_SHIFT-REAL_HPAGE_SHIFT)); i++) { | |
b0e55131 | 108 | purge_tlb_entries(mm, addr); |
736d2169 HD |
109 | addr += (1UL << REAL_HPAGE_SHIFT); |
110 | } | |
111 | } | |
112 | ||
b0e55131 HD |
113 | /* __set_huge_pte_at() must be called holding the pa_tlb_lock. */ |
114 | static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr, | |
736d2169 HD |
115 | pte_t *ptep, pte_t entry) |
116 | { | |
117 | unsigned long addr_start; | |
118 | int i; | |
119 | ||
120 | addr &= HPAGE_MASK; | |
121 | addr_start = addr; | |
122 | ||
123 | for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) { | |
b0e55131 | 124 | set_pte(ptep, entry); |
736d2169 HD |
125 | ptep++; |
126 | ||
736d2169 HD |
127 | addr += PAGE_SIZE; |
128 | pte_val(entry) += PAGE_SIZE; | |
129 | } | |
130 | ||
131 | purge_tlb_entries_huge(mm, addr_start); | |
132 | } | |
133 | ||
b0e55131 HD |
134 | void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, |
135 | pte_t *ptep, pte_t entry) | |
136 | { | |
137 | unsigned long flags; | |
138 | ||
139 | purge_tlb_start(flags); | |
140 | __set_huge_pte_at(mm, addr, ptep, entry); | |
141 | purge_tlb_end(flags); | |
142 | } | |
143 | ||
736d2169 HD |
144 | |
145 | pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, | |
146 | pte_t *ptep) | |
147 | { | |
b0e55131 | 148 | unsigned long flags; |
736d2169 HD |
149 | pte_t entry; |
150 | ||
b0e55131 | 151 | purge_tlb_start(flags); |
736d2169 | 152 | entry = *ptep; |
b0e55131 HD |
153 | __set_huge_pte_at(mm, addr, ptep, __pte(0)); |
154 | purge_tlb_end(flags); | |
736d2169 HD |
155 | |
156 | return entry; | |
157 | } | |
158 | ||
b0e55131 HD |
159 | |
160 | void huge_ptep_set_wrprotect(struct mm_struct *mm, | |
161 | unsigned long addr, pte_t *ptep) | |
162 | { | |
163 | unsigned long flags; | |
164 | pte_t old_pte; | |
165 | ||
166 | purge_tlb_start(flags); | |
167 | old_pte = *ptep; | |
168 | __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte)); | |
169 | purge_tlb_end(flags); | |
170 | } | |
171 | ||
172 | int huge_ptep_set_access_flags(struct vm_area_struct *vma, | |
173 | unsigned long addr, pte_t *ptep, | |
174 | pte_t pte, int dirty) | |
175 | { | |
176 | unsigned long flags; | |
177 | int changed; | |
178 | ||
179 | purge_tlb_start(flags); | |
180 | changed = !pte_same(*ptep, pte); | |
181 | if (changed) { | |
182 | __set_huge_pte_at(vma->vm_mm, addr, ptep, pte); | |
183 | } | |
184 | purge_tlb_end(flags); | |
185 | return changed; | |
186 | } | |
187 | ||
188 | ||
736d2169 HD |
189 | int pmd_huge(pmd_t pmd) |
190 | { | |
191 | return 0; | |
192 | } | |
193 | ||
194 | int pud_huge(pud_t pud) | |
195 | { | |
196 | return 0; | |
197 | } |