diff options
Diffstat (limited to 'arch/arm/mm/small_page.c')
| -rw-r--r-- | arch/arm/mm/small_page.c | 73 |
1 files changed, 49 insertions, 24 deletions
diff --git a/arch/arm/mm/small_page.c b/arch/arm/mm/small_page.c index 2f8cad9a3..6bdc6cfc7 100644 --- a/arch/arm/mm/small_page.c +++ b/arch/arm/mm/small_page.c @@ -5,6 +5,8 @@ * * Changelog: * 26/01/1996 RMK Cleaned up various areas to make little more generic + * 07/02/1999 RMK Support added for 16K and 32K page sizes + * containing 8K blocks */ #include <linux/signal.h> @@ -19,21 +21,32 @@ #include <linux/swap.h> #include <linux/smp.h> -#define SMALL_ALLOC_SHIFT (10) +#if PAGE_SIZE == 4096 +/* 2K blocks */ +#define SMALL_ALLOC_SHIFT (11) +#define NAME(x) x##_2k +#elif PAGE_SIZE == 32768 || PAGE_SIZE == 16384 +/* 8K blocks */ +#define SMALL_ALLOC_SHIFT (13) +#define NAME(x) x##_8k +#endif + #define SMALL_ALLOC_SIZE (1 << SMALL_ALLOC_SHIFT) #define NR_BLOCKS (PAGE_SIZE / SMALL_ALLOC_SIZE) +#define BLOCK_MASK ((1 << NR_BLOCKS) - 1) -#if NR_BLOCKS != 4 -#error I only support 4 blocks per page! -#endif - -#define USED(pg) ((atomic_read(&(pg)->count) >> 8) & 15) +#define USED(pg) ((atomic_read(&(pg)->count) >> 8) & BLOCK_MASK) #define SET_USED(pg,off) (atomic_read(&(pg)->count) |= 256 << off) #define CLEAR_USED(pg,off) (atomic_read(&(pg)->count) &= ~(256 << off)) +#define ALL_USED BLOCK_MASK #define IS_FREE(pg,off) (!(atomic_read(&(pg)->count) & (256 << off))) -#define PAGE_PTR(page,block) ((struct free_small_page *)((page) + \ +#define SM_PAGE_PTR(page,block) ((struct free_small_page *)((page) + \ ((block) << SMALL_ALLOC_SHIFT))) +#if NR_BLOCKS != 2 && NR_BLOCKS != 4 +#error I only support 2 or 4 blocks per page +#endif + struct free_small_page { unsigned long next; unsigned long prev; @@ -52,6 +65,7 @@ static unsigned char offsets[1<<NR_BLOCKS] = { 1, /* 0001 */ 0, /* 0010 */ 2, /* 0011 */ +#if NR_BLOCKS == 4 0, /* 0100 */ 1, /* 0101 */ 0, /* 0110 */ @@ -64,6 +78,7 @@ static unsigned char offsets[1<<NR_BLOCKS] = { 1, /* 1101 */ 0, /* 1110 */ 4 /* 1111 */ +#endif }; static inline void clear_page_links(unsigned long page) @@ -72,7 +87,7 @@ static inline void clear_page_links(unsigned long page) int i; for (i = 0; i < NR_BLOCKS; i++) { - fsp = PAGE_PTR(page, i); + fsp = SM_PAGE_PTR(page, i); fsp->next = fsp->prev = 0; } } @@ -90,7 +105,7 @@ static inline void set_page_links_prev(unsigned long page, unsigned long prev) for (i = 0; i < NR_BLOCKS; i++) { if (mask & (1 << i)) continue; - fsp = PAGE_PTR(page, i); + fsp = SM_PAGE_PTR(page, i); fsp->prev = prev; } } @@ -108,12 +123,12 @@ static inline void set_page_links_next(unsigned long page, unsigned long next) for (i = 0; i < NR_BLOCKS; i++) { if (mask & (1 << i)) continue; - fsp = PAGE_PTR(page, i); + fsp = SM_PAGE_PTR(page, i); fsp->next = next; } } -unsigned long get_small_page(int priority) +unsigned long NAME(get_page)(int priority) { struct free_small_page *fsp; unsigned long new_page; @@ -129,8 +144,8 @@ again: page = mem_map + MAP_NR(small_page_ptr); offset = offsets[USED(page)]; SET_USED(page, offset); - new_page = (unsigned long)PAGE_PTR(small_page_ptr, offset); - if (USED(page) == 15) { + new_page = (unsigned long)SM_PAGE_PTR(small_page_ptr, offset); + if (USED(page) == ALL_USED) { fsp = (struct free_small_page *)new_page; set_page_links_prev (fsp->next, 0); small_page_ptr = fsp->next; @@ -156,30 +171,31 @@ need_new_page: goto again; } -void free_small_page(unsigned long spage) +void NAME(free_page)(unsigned long spage) { struct free_small_page *ofsp, *cfsp; unsigned long flags; struct page *page; int offset, oldoffset; + if (!spage) + goto none; + offset = (spage >> SMALL_ALLOC_SHIFT) & (NR_BLOCKS - 1); spage -= offset << SMALL_ALLOC_SHIFT; page = mem_map + MAP_NR(spage); - if (!PageReserved(page) || !USED(page)) { - printk ("Trying to free non-small page from %p\n", __builtin_return_address(0)); - return; - } - if (IS_FREE(page, offset)) { - printk ("Trying to free free small page from %p\n", __builtin_return_address(0)); - return; - } + if (!PageReserved(page) || !USED(page)) + goto non_small; + + if (IS_FREE(page, offset)) + goto free; + save_flags_cli (flags); oldoffset = offsets[USED(page)]; CLEAR_USED(page, offset); - ofsp = PAGE_PTR(spage, oldoffset); - cfsp = PAGE_PTR(spage, offset); + ofsp = SM_PAGE_PTR(spage, oldoffset); + cfsp = SM_PAGE_PTR(spage, offset); if (oldoffset == NR_BLOCKS) { /* going from totally used to mostly used */ cfsp->prev = 0; @@ -197,4 +213,13 @@ void free_small_page(unsigned long spage) } else *cfsp = *ofsp; restore_flags(flags); + return; + +non_small: + printk ("Trying to free non-small page from %p\n", __builtin_return_address(0)); + return; +free: + printk ("Trying to free free small page from %p\n", __builtin_return_address(0)); +none: + return; } |