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/*
* linux/include/asm-xtensa/pgalloc.h
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Copyright (C) 2001-2005 Tensilica Inc.
*/
#ifndef _XTENSA_PGALLOC_H
#define _XTENSA_PGALLOC_H
#ifdef __KERNEL__
#include <linux/config.h>
#include <linux/threads.h>
#include <linux/highmem.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
/* Cache aliasing:
*
* If the cache size for one way is greater than the page size, we have to
* deal with cache aliasing. The cache index is wider than the page size:
*
* |cache |
* |pgnum |page| virtual address
* |xxxxxX|zzzz|
* | | |
* \ / | |
* trans.| |
* / \ | |
* |yyyyyY|zzzz| physical address
*
* When the page number is translated to the physical page address, the lowest
* bit(s) (X) that are also part of the cache index are also translated (Y).
* If this translation changes this bit (X), the cache index is also afected,
* thus resulting in a different cache line than before.
* The kernel does not provide a mechanism to ensure that the page color
* (represented by this bit) remains the same when allocated or when pages
* are remapped. When user pages are mapped into kernel space, the color of
* the page might also change.
*
* We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2
* to temporarily map a patch so we can match the color.
*/
#if (DCACHE_WAY_SIZE > PAGE_SIZE)
# define PAGE_COLOR_MASK (PAGE_MASK & (DCACHE_WAY_SIZE-1))
# define PAGE_COLOR(a) \
(((unsigned long)(a)&PAGE_COLOR_MASK) >> PAGE_SHIFT)
# define PAGE_COLOR_EQ(a,b) \
((((unsigned long)(a) ^ (unsigned long)(b)) & PAGE_COLOR_MASK) == 0)
# define PAGE_COLOR_MAP0(v) \
(VMALLOC_END + ((unsigned long)(v) & PAGE_COLOR_MASK))
# define PAGE_COLOR_MAP1(v) \
(VMALLOC_END + ((unsigned long)(v) & PAGE_COLOR_MASK) + DCACHE_WAY_SIZE)
#endif
/*
* Allocating and freeing a pmd is trivial: the 1-entry pmd is
* inside the pgd, so has no extra memory associated with it.
*/
#define pgd_free(pgd) free_page((unsigned long)(pgd))
#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
static inline void
pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *pte)
{
pmd_val(*(pmdp)) = (unsigned long)(pte);
__asm__ __volatile__ ("memw; dhwb %0, 0; dsync" :: "a" (pmdp));
}
static inline void
pmd_populate(struct mm_struct *mm, pmd_t *pmdp, struct page *page)
{
pmd_val(*(pmdp)) = (unsigned long)page_to_virt(page);
__asm__ __volatile__ ("memw; dhwb %0, 0; dsync" :: "a" (pmdp));
}
#else
# define pmd_populate_kernel(mm, pmdp, pte) \
(pmd_val(*(pmdp)) = (unsigned long)(pte))
# define pmd_populate(mm, pmdp, page) \
(pmd_val(*(pmdp)) = (unsigned long)page_to_virt(page))
#endif
static inline pgd_t*
pgd_alloc(struct mm_struct *mm)
{
pgd_t *pgd;
pgd = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGD_ORDER);
if (likely(pgd != NULL))
__flush_dcache_page((unsigned long)pgd);
return pgd;
}
extern pte_t* pte_alloc_one_kernel(struct mm_struct* mm, unsigned long addr);
extern struct page* pte_alloc_one(struct mm_struct* mm, unsigned long addr);
#define pte_free_kernel(pte) free_page((unsigned long)pte)
#define pte_free(pte) __free_page(pte)
#endif /* __KERNEL__ */
#endif /* _XTENSA_PGALLOC_H */
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