xref: /openbmc/linux/arch/xtensa/include/asm/pgalloc.h (revision e2c75e76)
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 #ifdef __KERNEL__
15 
16 #include <linux/highmem.h>
17 #include <linux/slab.h>
18 
19 /*
20  * Allocating and freeing a pmd is trivial: the 1-entry pmd is
21  * inside the pgd, so has no extra memory associated with it.
22  */
23 
24 #define pmd_populate_kernel(mm, pmdp, ptep)				     \
25 	(pmd_val(*(pmdp)) = ((unsigned long)ptep))
26 #define pmd_populate(mm, pmdp, page)					     \
27 	(pmd_val(*(pmdp)) = ((unsigned long)page_to_virt(page)))
28 #define pmd_pgtable(pmd) pmd_page(pmd)
29 
30 static inline pgd_t*
31 pgd_alloc(struct mm_struct *mm)
32 {
33 	return (pgd_t*) __get_free_pages(GFP_KERNEL | __GFP_ZERO, PGD_ORDER);
34 }
35 
36 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
37 {
38 	free_page((unsigned long)pgd);
39 }
40 
41 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
42 					 unsigned long address)
43 {
44 	pte_t *ptep;
45 	int i;
46 
47 	ptep = (pte_t *)__get_free_page(GFP_KERNEL);
48 	if (!ptep)
49 		return NULL;
50 	for (i = 0; i < 1024; i++)
51 		pte_clear(NULL, 0, ptep + i);
52 	return ptep;
53 }
54 
55 static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
56 					unsigned long addr)
57 {
58 	pte_t *pte;
59 	struct page *page;
60 
61 	pte = pte_alloc_one_kernel(mm, addr);
62 	if (!pte)
63 		return NULL;
64 	page = virt_to_page(pte);
65 	if (!pgtable_page_ctor(page)) {
66 		__free_page(page);
67 		return NULL;
68 	}
69 	return page;
70 }
71 
72 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
73 {
74 	free_page((unsigned long)pte);
75 }
76 
77 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
78 {
79 	pgtable_page_dtor(pte);
80 	__free_page(pte);
81 }
82 #define pmd_pgtable(pmd) pmd_page(pmd)
83 
84 #endif /* __KERNEL__ */
85 #endif /* _XTENSA_PGALLOC_H */
86