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