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 #include <linux/bootmem.h>
27 
28 extern int mem_init_done;
29 
30 #define pmd_populate_kernel(mm, pmd, pte) \
31 	set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
32 
33 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
34 				struct page *pte)
35 {
36 	set_pmd(pmd, __pmd(_KERNPG_TABLE +
37 		     ((unsigned long)page_to_pfn(pte) <<
38 		     (unsigned long) PAGE_SHIFT)));
39 }
40 
41 /*
42  * Allocate and free page tables.
43  */
44 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
45 {
46 	pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
47 
48 	if (ret) {
49 		memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
50 		memcpy(ret + USER_PTRS_PER_PGD,
51 		       swapper_pg_dir + USER_PTRS_PER_PGD,
52 		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
53 
54 	}
55 	return ret;
56 }
57 
58 #if 0
59 /* FIXME: This seems to be the preferred style, but we are using
60  * current_pgd (from mm->pgd) to load kernel pages so we need it
61  * initialized.  This needs to be looked into.
62  */
63 extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
64 {
65 	return (pgd_t *)get_zeroed_page(GFP_KERNEL);
66 }
67 #endif
68 
69 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
70 {
71 	free_page((unsigned long)pgd);
72 }
73 
74 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address);
75 
76 static inline struct page *pte_alloc_one(struct mm_struct *mm,
77 					 unsigned long address)
78 {
79 	struct page *pte;
80 	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
81 	if (!pte)
82 		return NULL;
83 	clear_page(page_address(pte));
84 	if (!pgtable_page_ctor(pte)) {
85 		__free_page(pte);
86 		return NULL;
87 	}
88 	return pte;
89 }
90 
91 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
92 {
93 	free_page((unsigned long)pte);
94 }
95 
96 static inline void pte_free(struct mm_struct *mm, struct page *pte)
97 {
98 	pgtable_page_dtor(pte);
99 	__free_page(pte);
100 }
101 
102 
103 #define __pte_free_tlb(tlb, pte, addr) tlb_remove_page((tlb), (pte))
104 #define pmd_pgtable(pmd) pmd_page(pmd)
105 
106 #define check_pgt_cache()          do { } while (0)
107 
108 #endif
109