1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * OpenRISC Linux
4  *
5  * Linux architectural port borrowing liberally from similar works of
6  * others.  All original copyrights apply as per the original source
7  * declaration.
8  *
9  * OpenRISC implementation:
10  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12  * et al.
13  */
14 
15 #ifndef __ASM_OPENRISC_PGALLOC_H
16 #define __ASM_OPENRISC_PGALLOC_H
17 
18 #include <asm/page.h>
19 #include <linux/threads.h>
20 #include <linux/mm.h>
21 #include <linux/memblock.h>
22 
23 extern int mem_init_done;
24 
25 #define pmd_populate_kernel(mm, pmd, pte) \
26 	set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
27 
28 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
29 				struct page *pte)
30 {
31 	set_pmd(pmd, __pmd(_KERNPG_TABLE +
32 		     ((unsigned long)page_to_pfn(pte) <<
33 		     (unsigned long) PAGE_SHIFT)));
34 }
35 
36 /*
37  * Allocate and free page tables.
38  */
39 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
40 {
41 	pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
42 
43 	if (ret) {
44 		memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
45 		memcpy(ret + USER_PTRS_PER_PGD,
46 		       swapper_pg_dir + USER_PTRS_PER_PGD,
47 		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
48 
49 	}
50 	return ret;
51 }
52 
53 #if 0
54 /* FIXME: This seems to be the preferred style, but we are using
55  * current_pgd (from mm->pgd) to load kernel pages so we need it
56  * initialized.  This needs to be looked into.
57  */
58 extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
59 {
60 	return (pgd_t *)get_zeroed_page(GFP_KERNEL);
61 }
62 #endif
63 
64 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
65 {
66 	free_page((unsigned long)pgd);
67 }
68 
69 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
70 
71 static inline struct page *pte_alloc_one(struct mm_struct *mm)
72 {
73 	struct page *pte;
74 	pte = alloc_pages(GFP_KERNEL, 0);
75 	if (!pte)
76 		return NULL;
77 	clear_page(page_address(pte));
78 	if (!pgtable_page_ctor(pte)) {
79 		__free_page(pte);
80 		return NULL;
81 	}
82 	return pte;
83 }
84 
85 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
86 {
87 	free_page((unsigned long)pte);
88 }
89 
90 static inline void pte_free(struct mm_struct *mm, struct page *pte)
91 {
92 	pgtable_page_dtor(pte);
93 	__free_page(pte);
94 }
95 
96 #define __pte_free_tlb(tlb, pte, addr)	\
97 do {					\
98 	pgtable_page_dtor(pte);		\
99 	tlb_remove_page((tlb), (pte));	\
100 } while (0)
101 
102 #define pmd_pgtable(pmd) pmd_page(pmd)
103 
104 #define check_pgt_cache()          do { } while (0)
105 
106 #endif
107