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
hugetlb_get_unmapped_area(struct file * file,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)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
huge_pte_alloc(struct mm_struct * mm,unsigned long addr,unsigned long sz)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
huge_pte_offset(struct mm_struct * mm,unsigned long addr)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 */
purge_tlb_entries_huge(struct mm_struct * mm,unsigned long addr)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++) {
108 purge_tlb_entries(mm, addr);
109 addr += (1UL << REAL_HPAGE_SHIFT);
110 }
111 }
112
113 /* __set_huge_pte_at() must be called holding the pa_tlb_lock. */
__set_huge_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t entry)114 static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
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++) {
124 set_pte(ptep, entry);
125 ptep++;
126
127 addr += PAGE_SIZE;
128 pte_val(entry) += PAGE_SIZE;
129 }
130
131 purge_tlb_entries_huge(mm, addr_start);
132 }
133
set_huge_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t entry)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
144
huge_ptep_get_and_clear(struct mm_struct * mm,unsigned long addr,pte_t * ptep)145 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
146 pte_t *ptep)
147 {
148 unsigned long flags;
149 pte_t entry;
150
151 purge_tlb_start(flags);
152 entry = *ptep;
153 __set_huge_pte_at(mm, addr, ptep, __pte(0));
154 purge_tlb_end(flags);
155
156 return entry;
157 }
158
159
huge_ptep_set_wrprotect(struct mm_struct * mm,unsigned long addr,pte_t * ptep)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
huge_ptep_set_access_flags(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep,pte_t pte,int dirty)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
pmd_huge(pmd_t pmd)189 int pmd_huge(pmd_t pmd)
190 {
191 return 0;
192 }
193
pud_huge(pud_t pud)194 int pud_huge(pud_t pud)
195 {
196 return 0;
197 }
198