diff options
Diffstat (limited to 'pfinet/linux-src/include/linux/pagemap.h')
| -rw-r--r-- | pfinet/linux-src/include/linux/pagemap.h | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/pfinet/linux-src/include/linux/pagemap.h b/pfinet/linux-src/include/linux/pagemap.h new file mode 100644 index 00000000..3e1e89b4 --- /dev/null +++ b/pfinet/linux-src/include/linux/pagemap.h @@ -0,0 +1,153 @@ +#ifndef _LINUX_PAGEMAP_H +#define _LINUX_PAGEMAP_H + +#include <asm/system.h> + +/* + * Page-mapping primitive inline functions + * + * Copyright 1995 Linus Torvalds + */ + +#include <linux/mm.h> +#include <linux/fs.h> + +static inline unsigned long page_address(struct page * page) +{ + return PAGE_OFFSET + PAGE_SIZE * (page - mem_map); +} + +/* + * The page cache can done in larger chunks than + * one page, because it allows for more efficient + * throughput (it can then be mapped into user + * space in smaller chunks for same flexibility). + * + * Or rather, it _will_ be done in larger chunks. + */ +#define PAGE_CACHE_SHIFT PAGE_SHIFT +#define PAGE_CACHE_SIZE PAGE_SIZE +#define PAGE_CACHE_MASK PAGE_MASK + +#define page_cache_alloc() __get_free_page(GFP_USER) +#define page_cache_free(x) free_page(x) +#define page_cache_release(x) __free_page(x) + +/* + * From a kernel address, get the "struct page *" + */ +#define page_cache_entry(x) (mem_map + MAP_NR(x)) + +#define PAGE_HASH_BITS 12 +#define PAGE_HASH_SIZE (1 << PAGE_HASH_BITS) + +extern unsigned long page_cache_size; /* # of pages currently in the hash table */ +extern struct page * page_hash_table[PAGE_HASH_SIZE]; + +/* + * We use a power-of-two hash table to avoid a modulus, + * and get a reasonable hash by knowing roughly how the + * inode pointer and offsets are distributed (ie, we + * roughly know which bits are "significant") + */ +static inline unsigned long _page_hashfn(struct inode * inode, unsigned long offset) +{ +#define i (((unsigned long) inode)/(sizeof(struct inode) & ~ (sizeof(struct inode) - 1))) +#define o (offset >> PAGE_SHIFT) +#define s(x) ((x)+((x)>>PAGE_HASH_BITS)) + return s(i+o) & (PAGE_HASH_SIZE-1); +#undef i +#undef o +#undef s +} + +#define page_hash(inode,offset) (page_hash_table+_page_hashfn(inode,offset)) + +static inline struct page * __find_page(struct inode * inode, unsigned long offset, struct page *page) +{ + goto inside; + for (;;) { + page = page->next_hash; +inside: + if (!page) + goto not_found; + if (page->inode != inode) + continue; + if (page->offset == offset) + break; + } + /* Found the page. */ + atomic_inc(&page->count); + set_bit(PG_referenced, &page->flags); +not_found: + return page; +} + +static inline struct page *find_page(struct inode * inode, unsigned long offset) +{ + return __find_page(inode, offset, *page_hash(inode, offset)); +} + +static inline void remove_page_from_hash_queue(struct page * page) +{ + if(page->pprev_hash) { + if(page->next_hash) + page->next_hash->pprev_hash = page->pprev_hash; + *page->pprev_hash = page->next_hash; + page->pprev_hash = NULL; + } + page_cache_size--; +} + +static inline void __add_page_to_hash_queue(struct page * page, struct page **p) +{ + page_cache_size++; + if((page->next_hash = *p) != NULL) + (*p)->pprev_hash = &page->next_hash; + *p = page; + page->pprev_hash = p; +} + +static inline void add_page_to_hash_queue(struct page * page, struct inode * inode, unsigned long offset) +{ + __add_page_to_hash_queue(page, page_hash(inode,offset)); +} + +static inline void remove_page_from_inode_queue(struct page * page) +{ + struct inode * inode = page->inode; + + page->inode = NULL; + inode->i_nrpages--; + if (inode->i_pages == page) + inode->i_pages = page->next; + if (page->next) + page->next->prev = page->prev; + if (page->prev) + page->prev->next = page->next; + page->next = NULL; + page->prev = NULL; +} + +static inline void add_page_to_inode_queue(struct inode * inode, struct page * page) +{ + struct page **p = &inode->i_pages; + + inode->i_nrpages++; + page->inode = inode; + page->prev = NULL; + if ((page->next = *p) != NULL) + page->next->prev = page; + *p = page; +} + +extern void __wait_on_page(struct page *); +static inline void wait_on_page(struct page * page) +{ + if (PageLocked(page)) + __wait_on_page(page); +} + +extern void update_vm_cache(struct inode *, unsigned long, const char *, int); + +#endif |