summaryrefslogtreecommitdiffstats
path: root/arch/parisc/mm/hugetlbpage.c
blob: 5d6eea925cf4ec979e906b118a682f318a199f01 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
/*
 * PARISC64 Huge TLB page support.
 *
 * This parisc implementation is heavily based on the SPARC and x86 code.
 *
 * Copyright (C) 2015 Helge Deller <deller@gmx.de>
 */

#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/sysctl.h>

#include <asm/mman.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>


unsigned long
hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
		unsigned long len, unsigned long pgoff, unsigned long flags)
{
	struct hstate *h = hstate_file(file);

	if (len & ~huge_page_mask(h))
		return -EINVAL;
	if (len > TASK_SIZE)
		return -ENOMEM;

	if (flags & MAP_FIXED)
		if (prepare_hugepage_range(file, addr, len))
			return -EINVAL;

	if (addr)
		addr = ALIGN(addr, huge_page_size(h));

	/* we need to make sure the colouring is OK */
	return arch_get_unmapped_area(file, addr, len, pgoff, flags);
}


pte_t *huge_pte_alloc(struct mm_struct *mm,
			unsigned long addr, unsigned long sz)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte = NULL;

	/* We must align the address, because our caller will run
	 * set_huge_pte_at() on whatever we return, which writes out
	 * all of the sub-ptes for the hugepage range.  So we have
	 * to give it the first such sub-pte.
	 */
	addr &= HPAGE_MASK;

	pgd = pgd_offset(mm, addr);
	pud = pud_alloc(mm, pgd, addr);
	if (pud) {
		pmd = pmd_alloc(mm, pud, addr);
		if (pmd)
			pte = pte_alloc_map(mm, pmd, addr);
	}
	return pte;
}

pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte = NULL;

	addr &= HPAGE_MASK;

	pgd = pgd_offset(mm, addr);
	if (!pgd_none(*pgd)) {
		pud = pud_offset(pgd, addr);
		if (!pud_none(*pud)) {
			pmd = pmd_offset(pud, addr);
			if (!pmd_none(*pmd))
				pte = pte_offset_map(pmd, addr);
		}
	}
	return pte;
}

/* Purge data and instruction TLB entries.  Must be called holding
 * the pa_tlb_lock.  The TLB purge instructions are slow on SMP
 * machines since the purge must be broadcast to all CPUs.
 */
static inline void purge_tlb_entries_huge(struct mm_struct *mm, unsigned long addr)
{
	int i;

	/* We may use multiple physical huge pages (e.g. 2x1 MB) to emulate
	 * Linux standard huge pages (e.g. 2 MB) */
	BUILD_BUG_ON(REAL_HPAGE_SHIFT > HPAGE_SHIFT);

	addr &= HPAGE_MASK;
	addr |= _HUGE_PAGE_SIZE_ENCODING_DEFAULT;

	for (i = 0; i < (1 << (HPAGE_SHIFT-REAL_HPAGE_SHIFT)); i++) {
		purge_tlb_entries(mm, addr);
		addr += (1UL << REAL_HPAGE_SHIFT);
	}
}

/* __set_huge_pte_at() must be called holding the pa_tlb_lock. */
static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
		     pte_t *ptep, pte_t entry)
{
	unsigned long addr_start;
	int i;

	addr &= HPAGE_MASK;
	addr_start = addr;

	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
		set_pte(ptep, entry);
		ptep++;

		addr += PAGE_SIZE;
		pte_val(entry) += PAGE_SIZE;
	}

	purge_tlb_entries_huge(mm, addr_start);
}

void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
		     pte_t *ptep, pte_t entry)
{
	unsigned long flags;

	purge_tlb_start(flags);
	__set_huge_pte_at(mm, addr, ptep, entry);
	purge_tlb_end(flags);
}


pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
			      pte_t *ptep)
{
	unsigned long flags;
	pte_t entry;

	purge_tlb_start(flags);
	entry = *ptep;
	__set_huge_pte_at(mm, addr, ptep, __pte(0));
	purge_tlb_end(flags);

	return entry;
}


void huge_ptep_set_wrprotect(struct mm_struct *mm,
				unsigned long addr, pte_t *ptep)
{
	unsigned long flags;
	pte_t old_pte;

	purge_tlb_start(flags);
	old_pte = *ptep;
	__set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
	purge_tlb_end(flags);
}

int huge_ptep_set_access_flags(struct vm_area_struct *vma,
				unsigned long addr, pte_t *ptep,
				pte_t pte, int dirty)
{
	unsigned long flags;
	int changed;

	purge_tlb_start(flags);
	changed = !pte_same(*ptep, pte);
	if (changed) {
		__set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
	}
	purge_tlb_end(flags);
	return changed;
}


int pmd_huge(pmd_t pmd)
{
	return 0;
}

int pud_huge(pud_t pud)
{
	return 0;
}