xref: /openbmc/linux/arch/xtensa/include/asm/pgalloc.h (revision 4984dd069f2995f239f075199ee8c0d9f020bcd9)
1 /*
2  * include/asm-xtensa/pgalloc.h
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * Copyright (C) 2001-2007 Tensilica Inc.
9  */
10 
11 #ifndef _XTENSA_PGALLOC_H
12 #define _XTENSA_PGALLOC_H
13 
14 #include <linux/highmem.h>
15 #include <linux/slab.h>
16 
17 /*
18  * Allocating and freeing a pmd is trivial: the 1-entry pmd is
19  * inside the pgd, so has no extra memory associated with it.
20  */
21 
22 #define pmd_populate_kernel(mm, pmdp, ptep)				     \
23 	(pmd_val(*(pmdp)) = ((unsigned long)ptep))
24 #define pmd_populate(mm, pmdp, page)					     \
25 	(pmd_val(*(pmdp)) = ((unsigned long)page_to_virt(page)))
26 #define pmd_pgtable(pmd) pmd_page(pmd)
27 
28 static inline pgd_t*
29 pgd_alloc(struct mm_struct *mm)
30 {
31 	return (pgd_t*) __get_free_pages(GFP_KERNEL | __GFP_ZERO, PGD_ORDER);
32 }
33 
34 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
35 {
36 	free_page((unsigned long)pgd);
37 }
38 
39 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
40 {
41 	pte_t *ptep;
42 	int i;
43 
44 	ptep = (pte_t *)__get_free_page(GFP_KERNEL);
45 	if (!ptep)
46 		return NULL;
47 	for (i = 0; i < 1024; i++)
48 		pte_clear(NULL, 0, ptep + i);
49 	return ptep;
50 }
51 
52 static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
53 {
54 	pte_t *pte;
55 	struct page *page;
56 
57 	pte = pte_alloc_one_kernel(mm);
58 	if (!pte)
59 		return NULL;
60 	page = virt_to_page(pte);
61 	if (!pgtable_page_ctor(page)) {
62 		__free_page(page);
63 		return NULL;
64 	}
65 	return page;
66 }
67 
68 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
69 {
70 	free_page((unsigned long)pte);
71 }
72 
73 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
74 {
75 	pgtable_page_dtor(pte);
76 	__free_page(pte);
77 }
78 #define pmd_pgtable(pmd) pmd_page(pmd)
79 
80 #endif /* _XTENSA_PGALLOC_H */
81