Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * linux/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) 2001-2005 Tensilica Inc.
9 */
10
11#ifndef _XTENSA_PGALLOC_H
12#define _XTENSA_PGALLOC_H
13
14#ifdef __KERNEL__
15
16#include <linux/config.h>
17#include <linux/threads.h>
18#include <linux/highmem.h>
19#include <asm/processor.h>
20#include <asm/cacheflush.h>
21
22
23/* Cache aliasing:
24 *
25 * If the cache size for one way is greater than the page size, we have to
26 * deal with cache aliasing. The cache index is wider than the page size:
27 *
28 * |cache |
29 * |pgnum |page| virtual address
30 * |xxxxxX|zzzz|
31 * | | |
32 * \ / | |
33 * trans.| |
34 * / \ | |
35 * |yyyyyY|zzzz| physical address
36 *
37 * When the page number is translated to the physical page address, the lowest
38 * bit(s) (X) that are also part of the cache index are also translated (Y).
39 * If this translation changes this bit (X), the cache index is also afected,
40 * thus resulting in a different cache line than before.
41 * The kernel does not provide a mechanism to ensure that the page color
42 * (represented by this bit) remains the same when allocated or when pages
43 * are remapped. When user pages are mapped into kernel space, the color of
44 * the page might also change.
45 *
46 * We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2
47 * to temporarily map a patch so we can match the color.
48 */
49
50#if (DCACHE_WAY_SIZE > PAGE_SIZE)
51# define PAGE_COLOR_MASK (PAGE_MASK & (DCACHE_WAY_SIZE-1))
52# define PAGE_COLOR(a) \
53 (((unsigned long)(a)&PAGE_COLOR_MASK) >> PAGE_SHIFT)
54# define PAGE_COLOR_EQ(a,b) \
55 ((((unsigned long)(a) ^ (unsigned long)(b)) & PAGE_COLOR_MASK) == 0)
56# define PAGE_COLOR_MAP0(v) \
57 (VMALLOC_END + ((unsigned long)(v) & PAGE_COLOR_MASK))
58# define PAGE_COLOR_MAP1(v) \
59 (VMALLOC_END + ((unsigned long)(v) & PAGE_COLOR_MASK) + DCACHE_WAY_SIZE)
60#endif
61
62/*
63 * Allocating and freeing a pmd is trivial: the 1-entry pmd is
64 * inside the pgd, so has no extra memory associated with it.
65 */
66
67#define pgd_free(pgd) free_page((unsigned long)(pgd))
68
69#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
70
71static inline void
72pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *pte)
73{
74 pmd_val(*(pmdp)) = (unsigned long)(pte);
75 __asm__ __volatile__ ("memw; dhwb %0, 0; dsync" :: "a" (pmdp));
76}
77
78static inline void
79pmd_populate(struct mm_struct *mm, pmd_t *pmdp, struct page *page)
80{
81 pmd_val(*(pmdp)) = (unsigned long)page_to_virt(page);
82 __asm__ __volatile__ ("memw; dhwb %0, 0; dsync" :: "a" (pmdp));
83}
84
85
86
87#else
88
89# define pmd_populate_kernel(mm, pmdp, pte) \
90 (pmd_val(*(pmdp)) = (unsigned long)(pte))
91# define pmd_populate(mm, pmdp, page) \
92 (pmd_val(*(pmdp)) = (unsigned long)page_to_virt(page))
93
94#endif
95
96static inline pgd_t*
97pgd_alloc(struct mm_struct *mm)
98{
99 pgd_t *pgd;
100
101 pgd = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGD_ORDER);
102
103 if (likely(pgd != NULL))
104 __flush_dcache_page((unsigned long)pgd);
105
106 return pgd;
107}
108
109extern pte_t* pte_alloc_one_kernel(struct mm_struct* mm, unsigned long addr);
110extern struct page* pte_alloc_one(struct mm_struct* mm, unsigned long addr);
111
112#define pte_free_kernel(pte) free_page((unsigned long)pte)
113#define pte_free(pte) __free_page(pte)
114
115#endif /* __KERNEL__ */
116#endif /* _XTENSA_PGALLOC_H */