Linux kernel mirror (for testing)
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linux
1/*
2 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2008-2009 PetaLogix
4 * Copyright (C) 2006 Atmark Techno, Inc.
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10
11#ifndef _ASM_MICROBLAZE_PGALLOC_H
12#define _ASM_MICROBLAZE_PGALLOC_H
13
14#ifdef CONFIG_MMU
15
16#include <linux/kernel.h> /* For min/max macros */
17#include <linux/highmem.h>
18#include <asm/setup.h>
19#include <asm/io.h>
20#include <asm/page.h>
21#include <asm/cache.h>
22
23#define PGDIR_ORDER 0
24
25/*
26 * This is handled very differently on MicroBlaze since out page tables
27 * are all 0's and I want to be able to use these zero'd pages elsewhere
28 * as well - it gives us quite a speedup.
29 * -- Cort
30 */
31extern struct pgtable_cache_struct {
32 unsigned long *pgd_cache;
33 unsigned long *pte_cache;
34 unsigned long pgtable_cache_sz;
35} quicklists;
36
37#define pgd_quicklist (quicklists.pgd_cache)
38#define pmd_quicklist ((unsigned long *)0)
39#define pte_quicklist (quicklists.pte_cache)
40#define pgtable_cache_size (quicklists.pgtable_cache_sz)
41
42extern unsigned long *zero_cache; /* head linked list of pre-zero'd pages */
43extern atomic_t zero_sz; /* # currently pre-zero'd pages */
44extern atomic_t zeropage_hits; /* # zero'd pages request that we've done */
45extern atomic_t zeropage_calls; /* # zero'd pages request that've been made */
46extern atomic_t zerototal; /* # pages zero'd over time */
47
48#define zero_quicklist (zero_cache)
49#define zero_cache_sz (zero_sz)
50#define zero_cache_calls (zeropage_calls)
51#define zero_cache_hits (zeropage_hits)
52#define zero_cache_total (zerototal)
53
54/*
55 * return a pre-zero'd page from the list,
56 * return NULL if none available -- Cort
57 */
58extern unsigned long get_zero_page_fast(void);
59
60extern void __bad_pte(pmd_t *pmd);
61
62extern inline pgd_t *get_pgd_slow(void)
63{
64 pgd_t *ret;
65
66 ret = (pgd_t *)__get_free_pages(GFP_KERNEL, PGDIR_ORDER);
67 if (ret != NULL)
68 clear_page(ret);
69 return ret;
70}
71
72extern inline pgd_t *get_pgd_fast(void)
73{
74 unsigned long *ret;
75
76 ret = pgd_quicklist;
77 if (ret != NULL) {
78 pgd_quicklist = (unsigned long *)(*ret);
79 ret[0] = 0;
80 pgtable_cache_size--;
81 } else
82 ret = (unsigned long *)get_pgd_slow();
83 return (pgd_t *)ret;
84}
85
86extern inline void free_pgd_fast(pgd_t *pgd)
87{
88 *(unsigned long **)pgd = pgd_quicklist;
89 pgd_quicklist = (unsigned long *) pgd;
90 pgtable_cache_size++;
91}
92
93extern inline void free_pgd_slow(pgd_t *pgd)
94{
95 free_page((unsigned long)pgd);
96}
97
98#define pgd_free(mm, pgd) free_pgd_fast(pgd)
99#define pgd_alloc(mm) get_pgd_fast()
100
101#define pmd_pgtable(pmd) pmd_page(pmd)
102
103/*
104 * We don't have any real pmd's, and this code never triggers because
105 * the pgd will always be present..
106 */
107#define pmd_alloc_one_fast(mm, address) ({ BUG(); ((pmd_t *)1); })
108#define pmd_alloc_one(mm, address) ({ BUG(); ((pmd_t *)2); })
109
110static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
111 unsigned long address)
112{
113 pte_t *pte;
114 extern int mem_init_done;
115 extern void *early_get_page(void);
116 if (mem_init_done) {
117 pte = (pte_t *)__get_free_page(GFP_KERNEL |
118 __GFP_REPEAT | __GFP_ZERO);
119 } else {
120 pte = (pte_t *)early_get_page();
121 if (pte)
122 clear_page(pte);
123 }
124 return pte;
125}
126
127static inline struct page *pte_alloc_one(struct mm_struct *mm,
128 unsigned long address)
129{
130 struct page *ptepage;
131
132#ifdef CONFIG_HIGHPTE
133 int flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
134#else
135 int flags = GFP_KERNEL | __GFP_REPEAT;
136#endif
137
138 ptepage = alloc_pages(flags, 0);
139 if (ptepage)
140 clear_highpage(ptepage);
141 return ptepage;
142}
143
144static inline pte_t *pte_alloc_one_fast(struct mm_struct *mm,
145 unsigned long address)
146{
147 unsigned long *ret;
148
149 ret = pte_quicklist;
150 if (ret != NULL) {
151 pte_quicklist = (unsigned long *)(*ret);
152 ret[0] = 0;
153 pgtable_cache_size--;
154 }
155 return (pte_t *)ret;
156}
157
158extern inline void pte_free_fast(pte_t *pte)
159{
160 *(unsigned long **)pte = pte_quicklist;
161 pte_quicklist = (unsigned long *) pte;
162 pgtable_cache_size++;
163}
164
165extern inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
166{
167 free_page((unsigned long)pte);
168}
169
170extern inline void pte_free_slow(struct page *ptepage)
171{
172 __free_page(ptepage);
173}
174
175extern inline void pte_free(struct mm_struct *mm, struct page *ptepage)
176{
177 __free_page(ptepage);
178}
179
180#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, (pte))
181
182#define pmd_populate(mm, pmd, pte) (pmd_val(*(pmd)) = page_address(pte))
183
184#define pmd_populate_kernel(mm, pmd, pte) \
185 (pmd_val(*(pmd)) = (unsigned long) (pte))
186
187/*
188 * We don't have any real pmd's, and this code never triggers because
189 * the pgd will always be present..
190 */
191#define pmd_alloc_one(mm, address) ({ BUG(); ((pmd_t *)2); })
192#define pmd_free(mm, x) do { } while (0)
193#define __pmd_free_tlb(tlb, x, addr) pmd_free((tlb)->mm, x)
194#define pgd_populate(mm, pmd, pte) BUG()
195
196extern int do_check_pgt_cache(int, int);
197
198#endif /* CONFIG_MMU */
199
200#define check_pgt_cache() do { } while (0)
201
202#endif /* _ASM_MICROBLAZE_PGALLOC_H */