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1/*
2 * Page table support for the Hexagon architecture
3 *
4 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 and
8 * only version 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301, USA.
19 */
20
21#ifndef _ASM_PGALLOC_H
22#define _ASM_PGALLOC_H
23
24#include <asm/mem-layout.h>
25#include <asm/atomic.h>
26
27#define check_pgt_cache() do {} while (0)
28
29extern unsigned long long kmap_generation;
30
31/*
32 * Page table creation interface
33 */
34static inline pgd_t *pgd_alloc(struct mm_struct *mm)
35{
36 pgd_t *pgd;
37
38 pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
39
40 /*
41 * There may be better ways to do this, but to ensure
42 * that new address spaces always contain the kernel
43 * base mapping, and to ensure that the user area is
44 * initially marked invalid, initialize the new map
45 * map with a copy of the kernel's persistent map.
46 */
47
48 memcpy(pgd, swapper_pg_dir, PTRS_PER_PGD*sizeof(pgd_t));
49 mm->context.generation = kmap_generation;
50
51 /* Physical version is what is passed to virtual machine on switch */
52 mm->context.ptbase = __pa(pgd);
53
54 return pgd;
55}
56
57static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
58{
59 free_page((unsigned long) pgd);
60}
61
62static inline struct page *pte_alloc_one(struct mm_struct *mm,
63 unsigned long address)
64{
65 struct page *pte;
66
67 pte = alloc_page(GFP_KERNEL | __GFP_ZERO);
68 if (!pte)
69 return NULL;
70 if (!pgtable_page_ctor(pte)) {
71 __free_page(pte);
72 return NULL;
73 }
74 return pte;
75}
76
77/* _kernel variant gets to use a different allocator */
78static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
79 unsigned long address)
80{
81 gfp_t flags = GFP_KERNEL | __GFP_ZERO;
82 return (pte_t *) __get_free_page(flags);
83}
84
85static inline void pte_free(struct mm_struct *mm, struct page *pte)
86{
87 pgtable_page_dtor(pte);
88 __free_page(pte);
89}
90
91static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
92{
93 free_page((unsigned long)pte);
94}
95
96static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
97 pgtable_t pte)
98{
99 /*
100 * Conveniently, zero in 3 LSB means indirect 4K page table.
101 * Not so convenient when you're trying to vary the page size.
102 */
103 set_pmd(pmd, __pmd(((unsigned long)page_to_pfn(pte) << PAGE_SHIFT) |
104 HEXAGON_L1_PTE_SIZE));
105}
106
107/*
108 * Other architectures seem to have ways of making all processes
109 * share the same pmd's for their kernel mappings, but the v0.3
110 * Hexagon VM spec has a "monolithic" L1 table for user and kernel
111 * segments. We track "generations" of the kernel map to minimize
112 * overhead, and update the "slave" copies of the kernel mappings
113 * as part of switch_mm. However, we still need to update the
114 * kernel map of the active thread who's calling pmd_populate_kernel...
115 */
116static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
117 pte_t *pte)
118{
119 extern spinlock_t kmap_gen_lock;
120 pmd_t *ppmd;
121 int pmdindex;
122
123 spin_lock(&kmap_gen_lock);
124 kmap_generation++;
125 mm->context.generation = kmap_generation;
126 current->active_mm->context.generation = kmap_generation;
127 spin_unlock(&kmap_gen_lock);
128
129 set_pmd(pmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
130
131 /*
132 * Now the "slave" copy of the current thread.
133 * This is pointer arithmetic, not byte addresses!
134 */
135 pmdindex = (pgd_t *)pmd - mm->pgd;
136 ppmd = (pmd_t *)current->active_mm->pgd + pmdindex;
137 set_pmd(ppmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
138 if (pmdindex > max_kernel_seg)
139 max_kernel_seg = pmdindex;
140}
141
142#define __pte_free_tlb(tlb, pte, addr) \
143do { \
144 pgtable_page_dtor((pte)); \
145 tlb_remove_page((tlb), (pte)); \
146} while (0)
147
148#endif
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Page table support for the Hexagon architecture
4 *
5 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
6 */
7
8#ifndef _ASM_PGALLOC_H
9#define _ASM_PGALLOC_H
10
11#include <asm/mem-layout.h>
12#include <asm/atomic.h>
13
14#include <asm-generic/pgalloc.h>
15
16extern unsigned long long kmap_generation;
17
18/*
19 * Page table creation interface
20 */
21static inline pgd_t *pgd_alloc(struct mm_struct *mm)
22{
23 pgd_t *pgd;
24
25 pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
26
27 /*
28 * There may be better ways to do this, but to ensure
29 * that new address spaces always contain the kernel
30 * base mapping, and to ensure that the user area is
31 * initially marked invalid, initialize the new map
32 * map with a copy of the kernel's persistent map.
33 */
34
35 memcpy(pgd, swapper_pg_dir, PTRS_PER_PGD*sizeof(pgd_t));
36 mm->context.generation = kmap_generation;
37
38 /* Physical version is what is passed to virtual machine on switch */
39 mm->context.ptbase = __pa(pgd);
40
41 return pgd;
42}
43
44static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
45 pgtable_t pte)
46{
47 /*
48 * Conveniently, zero in 3 LSB means indirect 4K page table.
49 * Not so convenient when you're trying to vary the page size.
50 */
51 set_pmd(pmd, __pmd(((unsigned long)page_to_pfn(pte) << PAGE_SHIFT) |
52 HEXAGON_L1_PTE_SIZE));
53}
54
55/*
56 * Other architectures seem to have ways of making all processes
57 * share the same pmd's for their kernel mappings, but the v0.3
58 * Hexagon VM spec has a "monolithic" L1 table for user and kernel
59 * segments. We track "generations" of the kernel map to minimize
60 * overhead, and update the "slave" copies of the kernel mappings
61 * as part of switch_mm. However, we still need to update the
62 * kernel map of the active thread who's calling pmd_populate_kernel...
63 */
64static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
65 pte_t *pte)
66{
67 extern spinlock_t kmap_gen_lock;
68 pmd_t *ppmd;
69 int pmdindex;
70
71 spin_lock(&kmap_gen_lock);
72 kmap_generation++;
73 mm->context.generation = kmap_generation;
74 current->active_mm->context.generation = kmap_generation;
75 spin_unlock(&kmap_gen_lock);
76
77 set_pmd(pmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
78
79 /*
80 * Now the "slave" copy of the current thread.
81 * This is pointer arithmetic, not byte addresses!
82 */
83 pmdindex = (pgd_t *)pmd - mm->pgd;
84 ppmd = (pmd_t *)current->active_mm->pgd + pmdindex;
85 set_pmd(ppmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
86 if (pmdindex > max_kernel_seg)
87 max_kernel_seg = pmdindex;
88}
89
90#define __pte_free_tlb(tlb, pte, addr) \
91do { \
92 pagetable_pte_dtor((page_ptdesc(pte))); \
93 tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte))); \
94} while (0)
95
96#endif