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
|
/*
* Page table support for the Hexagon architecture
*
* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#ifndef _ASM_PGALLOC_H
#define _ASM_PGALLOC_H
#include <asm/mem-layout.h>
#include <asm/atomic.h>
#define check_pgt_cache() do {} while (0)
extern unsigned long long kmap_generation;
/*
* Page table creation interface
*/
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *pgd;
pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
/*
* There may be better ways to do this, but to ensure
* that new address spaces always contain the kernel
* base mapping, and to ensure that the user area is
* initially marked invalid, initialize the new map
* map with a copy of the kernel's persistent map.
*/
memcpy(pgd, swapper_pg_dir, PTRS_PER_PGD*sizeof(pgd_t *));
mm->context.generation = kmap_generation;
/* Physical version is what is passed to virtual machine on switch */
mm->context.ptbase = __pa(pgd);
return pgd;
}
static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
free_page((unsigned long) pgd);
}
static inline struct page *pte_alloc_one(struct mm_struct *mm,
unsigned long address)
{
struct page *pte;
pte = alloc_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
if (pte)
pgtable_page_ctor(pte);
return pte;
}
/* _kernel variant gets to use a different allocator */
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
unsigned long address)
{
gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO;
return (pte_t *) __get_free_page(flags);
}
static inline void pte_free(struct mm_struct *mm, struct page *pte)
{
pgtable_page_dtor(pte);
__free_page(pte);
}
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
free_page((unsigned long)pte);
}
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
pgtable_t pte)
{
/*
* Conveniently, zero in 3 LSB means indirect 4K page table.
* Not so convenient when you're trying to vary the page size.
*/
set_pmd(pmd, __pmd(((unsigned long)page_to_pfn(pte) << PAGE_SHIFT) |
HEXAGON_L1_PTE_SIZE));
}
/*
* Other architectures seem to have ways of making all processes
* share the same pmd's for their kernel mappings, but the v0.3
* Hexagon VM spec has a "monolithic" L1 table for user and kernel
* segments. We track "generations" of the kernel map to minimize
* overhead, and update the "slave" copies of the kernel mappings
* as part of switch_mm. However, we still need to update the
* kernel map of the active thread who's calling pmd_populate_kernel...
*/
static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
pte_t *pte)
{
extern spinlock_t kmap_gen_lock;
pmd_t *ppmd;
int pmdindex;
spin_lock(&kmap_gen_lock);
kmap_generation++;
mm->context.generation = kmap_generation;
current->active_mm->context.generation = kmap_generation;
spin_unlock(&kmap_gen_lock);
set_pmd(pmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
/*
* Now the "slave" copy of the current thread.
* This is pointer arithmetic, not byte addresses!
*/
pmdindex = (pgd_t *)pmd - mm->pgd;
ppmd = (pmd_t *)current->active_mm->pgd + pmdindex;
set_pmd(ppmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
if (pmdindex > max_kernel_seg)
max_kernel_seg = pmdindex;
}
#define __pte_free_tlb(tlb, pte, addr) \
do { \
pgtable_page_dtor((pte)); \
tlb_remove_page((tlb), (pte)); \
} while (0)
#endif
|
