v2.6.22.24-op1
[linux-2.6.22.y-op.git] / include / asm-xtensa / pgalloc.h
blobd56ddf2055e12c263ad468391bbe4168985d0de1
1 /*
2 * linux/include/asm-xtensa/pgalloc.h
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.
8 * Copyright (C) 2001-2005 Tensilica Inc.
9 */
11 #ifndef _XTENSA_PGALLOC_H
12 #define _XTENSA_PGALLOC_H
14 #ifdef __KERNEL__
16 #include <linux/threads.h>
17 #include <linux/highmem.h>
18 #include <asm/processor.h>
19 #include <asm/cacheflush.h>
22 /* Cache aliasing:
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:
27 * |cache |
28 * |pgnum |page| virtual address
29 * |xxxxxX|zzzz|
30 * | | |
31 * \ / | |
32 * trans.| |
33 * / \ | |
34 * |yyyyyY|zzzz| physical address
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.
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.
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
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.
66 #define pgd_free(pgd) free_page((unsigned long)(pgd))
68 #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
70 static inline void
71 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *pte)
73 pmd_val(*(pmdp)) = (unsigned long)(pte);
74 __asm__ __volatile__ ("memw; dhwb %0, 0; dsync" :: "a" (pmdp));
77 static inline void
78 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, struct page *page)
80 pmd_val(*(pmdp)) = (unsigned long)page_to_virt(page);
81 __asm__ __volatile__ ("memw; dhwb %0, 0; dsync" :: "a" (pmdp));
86 #else
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))
93 #endif
95 static inline pgd_t*
96 pgd_alloc(struct mm_struct *mm)
98 pgd_t *pgd;
100 pgd = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGD_ORDER);
102 if (likely(pgd != NULL))
103 __flush_dcache_page((unsigned long)pgd);
105 return pgd;
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);
111 #define pte_free_kernel(pte) free_page((unsigned long)pte)
112 #define pte_free(pte) __free_page(pte)
114 #endif /* __KERNEL__ */
115 #endif /* _XTENSA_PGALLOC_H */