1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * PARISC64 Huge TLB page support.
4 *
5 * This parisc implementation is heavily based on the SPARC and x86 code.
6 *
7 * Copyright (C) 2015 Helge Deller <deller@gmx.de>
8 */
9
10 #include <linux/fs.h>
11 #include <linux/mm.h>
12 #include <linux/sched/mm.h>
13 #include <linux/hugetlb.h>
14 #include <linux/pagemap.h>
15 #include <linux/sysctl.h>
16
17 #include <asm/mman.h>
18 #include <asm/pgalloc.h>
19 #include <asm/tlb.h>
20 #include <asm/tlbflush.h>
21 #include <asm/cacheflush.h>
22 #include <asm/mmu_context.h>
23
24
25 unsigned long
hugetlb_get_unmapped_area(struct file * file,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)26 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
27 unsigned long len, unsigned long pgoff, unsigned long flags)
28 {
29 struct hstate *h = hstate_file(file);
30
31 if (len & ~huge_page_mask(h))
32 return -EINVAL;
33 if (len > TASK_SIZE)
34 return -ENOMEM;
35
36 if (flags & MAP_FIXED)
37 if (prepare_hugepage_range(file, addr, len))
38 return -EINVAL;
39
40 if (addr)
41 addr = ALIGN(addr, huge_page_size(h));
42
43 /* we need to make sure the colouring is OK */
44 return arch_get_unmapped_area(file, addr, len, pgoff, flags);
45 }
46
47
huge_pte_alloc(struct mm_struct * mm,unsigned long addr,unsigned long sz)48 pte_t *huge_pte_alloc(struct mm_struct *mm,
49 unsigned long addr, unsigned long sz)
50 {
51 pgd_t *pgd;
52 pud_t *pud;
53 pmd_t *pmd;
54 pte_t *pte = NULL;
55
56 /* We must align the address, because our caller will run
57 * set_huge_pte_at() on whatever we return, which writes out
58 * all of the sub-ptes for the hugepage range. So we have
59 * to give it the first such sub-pte.
60 */
61 addr &= HPAGE_MASK;
62
63 pgd = pgd_offset(mm, addr);
64 pud = pud_alloc(mm, pgd, addr);
65 if (pud) {
66 pmd = pmd_alloc(mm, pud, addr);
67 if (pmd)
68 pte = pte_alloc_map(mm, pmd, addr);
69 }
70 return pte;
71 }
72
huge_pte_offset(struct mm_struct * mm,unsigned long addr,unsigned long sz)73 pte_t *huge_pte_offset(struct mm_struct *mm,
74 unsigned long addr, unsigned long sz)
75 {
76 pgd_t *pgd;
77 pud_t *pud;
78 pmd_t *pmd;
79 pte_t *pte = NULL;
80
81 addr &= HPAGE_MASK;
82
83 pgd = pgd_offset(mm, addr);
84 if (!pgd_none(*pgd)) {
85 pud = pud_offset(pgd, addr);
86 if (!pud_none(*pud)) {
87 pmd = pmd_offset(pud, addr);
88 if (!pmd_none(*pmd))
89 pte = pte_offset_map(pmd, addr);
90 }
91 }
92 return pte;
93 }
94
95 /* Purge data and instruction TLB entries. Must be called holding
96 * the pa_tlb_lock. The TLB purge instructions are slow on SMP
97 * machines since the purge must be broadcast to all CPUs.
98 */
purge_tlb_entries_huge(struct mm_struct * mm,unsigned long addr)99 static inline void purge_tlb_entries_huge(struct mm_struct *mm, unsigned long addr)
100 {
101 int i;
102
103 /* We may use multiple physical huge pages (e.g. 2x1 MB) to emulate
104 * Linux standard huge pages (e.g. 2 MB) */
105 BUILD_BUG_ON(REAL_HPAGE_SHIFT > HPAGE_SHIFT);
106
107 addr &= HPAGE_MASK;
108 addr |= _HUGE_PAGE_SIZE_ENCODING_DEFAULT;
109
110 for (i = 0; i < (1 << (HPAGE_SHIFT-REAL_HPAGE_SHIFT)); i++) {
111 purge_tlb_entries(mm, addr);
112 addr += (1UL << REAL_HPAGE_SHIFT);
113 }
114 }
115
116 /* __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)117 static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
118 pte_t *ptep, pte_t entry)
119 {
120 unsigned long addr_start;
121 int i;
122
123 addr &= HPAGE_MASK;
124 addr_start = addr;
125
126 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
127 set_pte(ptep, entry);
128 ptep++;
129
130 addr += PAGE_SIZE;
131 pte_val(entry) += PAGE_SIZE;
132 }
133
134 purge_tlb_entries_huge(mm, addr_start);
135 }
136
set_huge_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t entry)137 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
138 pte_t *ptep, pte_t entry)
139 {
140 unsigned long flags;
141
142 spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);
143 __set_huge_pte_at(mm, addr, ptep, entry);
144 spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);
145 }
146
147
huge_ptep_get_and_clear(struct mm_struct * mm,unsigned long addr,pte_t * ptep)148 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
149 pte_t *ptep)
150 {
151 unsigned long flags;
152 pte_t entry;
153
154 spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);
155 entry = *ptep;
156 __set_huge_pte_at(mm, addr, ptep, __pte(0));
157 spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);
158
159 return entry;
160 }
161
162
huge_ptep_set_wrprotect(struct mm_struct * mm,unsigned long addr,pte_t * ptep)163 void huge_ptep_set_wrprotect(struct mm_struct *mm,
164 unsigned long addr, pte_t *ptep)
165 {
166 unsigned long flags;
167 pte_t old_pte;
168
169 spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);
170 old_pte = *ptep;
171 __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
172 spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);
173 }
174
huge_ptep_set_access_flags(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep,pte_t pte,int dirty)175 int huge_ptep_set_access_flags(struct vm_area_struct *vma,
176 unsigned long addr, pte_t *ptep,
177 pte_t pte, int dirty)
178 {
179 unsigned long flags;
180 int changed;
181 struct mm_struct *mm = vma->vm_mm;
182
183 spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);
184 changed = !pte_same(*ptep, pte);
185 if (changed) {
186 __set_huge_pte_at(mm, addr, ptep, pte);
187 }
188 spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);
189 return changed;
190 }
191
192
pmd_huge(pmd_t pmd)193 int pmd_huge(pmd_t pmd)
194 {
195 return 0;
196 }
197
pud_huge(pud_t pud)198 int pud_huge(pud_t pud)
199 {
200 return 0;
201 }
202
