From 9a8fd5589902153a134111ed7a40f9cca1f83254 Mon Sep 17 00:00:00 2001 From: Chris Zankel Date: Thu, 23 Jun 2005 22:01:26 -0700 Subject: [PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6 The attached patches provides part 6 of an architecture implementation for the Tensilica Xtensa CPU series. Signed-off-by: Chris Zankel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-xtensa/pgalloc.h | 116 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 include/asm-xtensa/pgalloc.h (limited to 'include/asm-xtensa/pgalloc.h') diff --git a/include/asm-xtensa/pgalloc.h b/include/asm-xtensa/pgalloc.h new file mode 100644 index 00000000000..734a8d06039 --- /dev/null +++ b/include/asm-xtensa/pgalloc.h @@ -0,0 +1,116 @@ +/* + * 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 +#include +#include +#include +#include + + +/* 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 */ -- cgit v1.2.3