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9a8fd558 CZ |
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 | ||
9a8fd558 CZ |
16 | #include <linux/threads.h> |
17 | #include <linux/highmem.h> | |
18 | #include <asm/processor.h> | |
19 | #include <asm/cacheflush.h> | |
20 | ||
21 | ||
22 | /* Cache aliasing: | |
23 | * | |
24 | * If the cache size for one way is greater than the page size, we have to | |
25 | * deal with cache aliasing. The cache index is wider than the page size: | |
26 | * | |
27 | * |cache | | |
28 | * |pgnum |page| virtual address | |
29 | * |xxxxxX|zzzz| | |
30 | * | | | | |
31 | * \ / | | | |
32 | * trans.| | | |
33 | * / \ | | | |
34 | * |yyyyyY|zzzz| physical address | |
35 | * | |
36 | * When the page number is translated to the physical page address, the lowest | |
37 | * bit(s) (X) that are also part of the cache index are also translated (Y). | |
38 | * If this translation changes this bit (X), the cache index is also afected, | |
39 | * thus resulting in a different cache line than before. | |
40 | * The kernel does not provide a mechanism to ensure that the page color | |
41 | * (represented by this bit) remains the same when allocated or when pages | |
42 | * are remapped. When user pages are mapped into kernel space, the color of | |
43 | * the page might also change. | |
44 | * | |
45 | * We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2 | |
46 | * to temporarily map a patch so we can match the color. | |
47 | */ | |
48 | ||
49 | #if (DCACHE_WAY_SIZE > PAGE_SIZE) | |
50 | # define PAGE_COLOR_MASK (PAGE_MASK & (DCACHE_WAY_SIZE-1)) | |
51 | # define PAGE_COLOR(a) \ | |
52 | (((unsigned long)(a)&PAGE_COLOR_MASK) >> PAGE_SHIFT) | |
53 | # define PAGE_COLOR_EQ(a,b) \ | |
54 | ((((unsigned long)(a) ^ (unsigned long)(b)) & PAGE_COLOR_MASK) == 0) | |
55 | # define PAGE_COLOR_MAP0(v) \ | |
56 | (VMALLOC_END + ((unsigned long)(v) & PAGE_COLOR_MASK)) | |
57 | # define PAGE_COLOR_MAP1(v) \ | |
58 | (VMALLOC_END + ((unsigned long)(v) & PAGE_COLOR_MASK) + DCACHE_WAY_SIZE) | |
59 | #endif | |
60 | ||
61 | /* | |
62 | * Allocating and freeing a pmd is trivial: the 1-entry pmd is | |
63 | * inside the pgd, so has no extra memory associated with it. | |
64 | */ | |
65 | ||
66 | #define pgd_free(pgd) free_page((unsigned long)(pgd)) | |
67 | ||
68 | #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK | |
69 | ||
70 | static inline void | |
71 | pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *pte) | |
72 | { | |
73 | pmd_val(*(pmdp)) = (unsigned long)(pte); | |
74 | __asm__ __volatile__ ("memw; dhwb %0, 0; dsync" :: "a" (pmdp)); | |
75 | } | |
76 | ||
77 | static inline void | |
78 | pmd_populate(struct mm_struct *mm, pmd_t *pmdp, struct page *page) | |
79 | { | |
80 | pmd_val(*(pmdp)) = (unsigned long)page_to_virt(page); | |
81 | __asm__ __volatile__ ("memw; dhwb %0, 0; dsync" :: "a" (pmdp)); | |
82 | } | |
83 | ||
84 | ||
85 | ||
86 | #else | |
87 | ||
88 | # define pmd_populate_kernel(mm, pmdp, pte) \ | |
89 | (pmd_val(*(pmdp)) = (unsigned long)(pte)) | |
90 | # define pmd_populate(mm, pmdp, page) \ | |
91 | (pmd_val(*(pmdp)) = (unsigned long)page_to_virt(page)) | |
92 | ||
93 | #endif | |
94 | ||
95 | static inline pgd_t* | |
96 | pgd_alloc(struct mm_struct *mm) | |
97 | { | |
98 | pgd_t *pgd; | |
99 | ||
100 | pgd = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGD_ORDER); | |
101 | ||
102 | if (likely(pgd != NULL)) | |
103 | __flush_dcache_page((unsigned long)pgd); | |
104 | ||
105 | return pgd; | |
106 | } | |
107 | ||
108 | extern pte_t* pte_alloc_one_kernel(struct mm_struct* mm, unsigned long addr); | |
109 | extern struct page* pte_alloc_one(struct mm_struct* mm, unsigned long addr); | |
110 | ||
111 | #define pte_free_kernel(pte) free_page((unsigned long)pte) | |
112 | #define pte_free(pte) __free_page(pte) | |
113 | ||
114 | #endif /* __KERNEL__ */ | |
115 | #endif /* _XTENSA_PGALLOC_H */ |