1 /*
2  * OpenRISC Linux
3  *
4  * Linux architectural port borrowing liberally from similar works of
5  * others.  All original copyrights apply as per the original source
6  * declaration.
7  *
8  * OpenRISC implementation:
9  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
11  * et al.
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  */
18 
19 #ifndef __ASM_OPENRISC_PGALLOC_H
20 #define __ASM_OPENRISC_PGALLOC_H
21 
22 #include <asm/page.h>
23 #include <linux/threads.h>
24 #include <linux/mm.h>
25 #include <linux/memblock.h>
26 
27 extern int mem_init_done;
28 
29 #define pmd_populate_kernel(mm, pmd, pte) \
30 	set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
31 
32 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
33 				struct page *pte)
34 {
35 	set_pmd(pmd, __pmd(_KERNPG_TABLE +
36 		     ((unsigned long)page_to_pfn(pte) <<
37 		     (unsigned long) PAGE_SHIFT)));
38 }
39 
40 /*
41  * Allocate and free page tables.
42  */
43 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
44 {
45 	pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
46 
47 	if (ret) {
48 		memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
49 		memcpy(ret + USER_PTRS_PER_PGD,
50 		       swapper_pg_dir + USER_PTRS_PER_PGD,
51 		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
52 
53 	}
54 	return ret;
55 }
56 
57 #if 0
58 /* FIXME: This seems to be the preferred style, but we are using
59  * current_pgd (from mm->pgd) to load kernel pages so we need it
60  * initialized.  This needs to be looked into.
61  */
62 extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
63 {
64 	return (pgd_t *)get_zeroed_page(GFP_KERNEL);
65 }
66 #endif
67 
68 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
69 {
70 	free_page((unsigned long)pgd);
71 }
72 
73 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
74 
75 static inline struct page *pte_alloc_one(struct mm_struct *mm)
76 {
77 	struct page *pte;
78 	pte = alloc_pages(GFP_KERNEL, 0);
79 	if (!pte)
80 		return NULL;
81 	clear_page(page_address(pte));
82 	if (!pgtable_page_ctor(pte)) {
83 		__free_page(pte);
84 		return NULL;
85 	}
86 	return pte;
87 }
88 
89 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
90 {
91 	free_page((unsigned long)pte);
92 }
93 
94 static inline void pte_free(struct mm_struct *mm, struct page *pte)
95 {
96 	pgtable_page_dtor(pte);
97 	__free_page(pte);
98 }
99 
100 #define __pte_free_tlb(tlb, pte, addr)	\
101 do {					\
102 	pgtable_page_dtor(pte);		\
103 	tlb_remove_page((tlb), (pte));	\
104 } while (0)
105 
106 #define pmd_pgtable(pmd) pmd_page(pmd)
107 
108 #define check_pgt_cache()          do { } while (0)
109 
110 #endif
111