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/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 70static inline void 71pmd_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 77static inline void 78pmd_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 95static inline pgd_t* 96pgd_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 108extern pte_t* pte_alloc_one_kernel(struct mm_struct* mm, unsigned long addr); 109extern 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 */ 116