diff options
Diffstat (limited to 'arch/m68k/atari/stram.c')
| -rw-r--r-- | arch/m68k/atari/stram.c | 918 |
1 files changed, 15 insertions, 903 deletions
diff --git a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c index 5a3c106..22e0481 100644 --- a/arch/m68k/atari/stram.c +++ b/arch/m68k/atari/stram.c @@ -15,11 +15,9 @@ #include <linux/kdev_t.h> #include <linux/major.h> #include <linux/init.h> -#include <linux/swap.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/pagemap.h> -#include <linux/shm.h> #include <linux/bootmem.h> #include <linux/mount.h> #include <linux/blkdev.h> @@ -33,8 +31,6 @@ #include <asm/io.h> #include <asm/semaphore.h> -#include <linux/swapops.h> - #undef DEBUG #ifdef DEBUG @@ -49,8 +45,7 @@ #include <linux/proc_fs.h> #endif -/* Pre-swapping comments: - * +/* * ++roman: * * New version of ST-Ram buffer allocation. Instead of using the @@ -75,76 +70,6 @@ * */ -/* - * New Nov 1997: Use ST-RAM as swap space! - * - * In the past, there were often problems with modules that require ST-RAM - * buffers. Such drivers have to use __get_dma_pages(), which unfortunately - * often isn't very successful in allocating more than 1 page :-( [1] The net - * result was that most of the time you couldn't insmod such modules (ataflop, - * ACSI, SCSI on Falcon, Atari internal framebuffer, not to speak of acsi_slm, - * which needs a 1 MB buffer... :-). - * - * To overcome this limitation, ST-RAM can now be turned into a very - * high-speed swap space. If a request for an ST-RAM buffer comes, the kernel - * now tries to unswap some pages on that swap device to make some free (and - * contiguous) space. This works much better in comparison to - * __get_dma_pages(), since used swap pages can be selectively freed by either - * moving them to somewhere else in swap space, or by reading them back into - * system memory. Ok, there operation of unswapping isn't really cheap (for - * each page, one has to go through the page tables of all processes), but it - * doesn't happen that often (only when allocation ST-RAM, i.e. when loading a - * module that needs ST-RAM). But it at least makes it possible to load such - * modules! - * - * It could also be that overall system performance increases a bit due to - * ST-RAM swapping, since slow ST-RAM isn't used anymore for holding data or - * executing code in. It's then just a (very fast, compared to disk) back - * storage for not-so-often needed data. (But this effect must be compared - * with the loss of total memory...) Don't know if the effect is already - * visible on a TT, where the speed difference between ST- and TT-RAM isn't - * that dramatic, but it should on machines where TT-RAM is really much faster - * (e.g. Afterburner). - * - * [1]: __get_free_pages() does a fine job if you only want one page, but if - * you want more (contiguous) pages, it can give you such a block only if - * there's already a free one. The algorithm can't try to free buffers or swap - * out something in order to make more free space, since all that page-freeing - * mechanisms work "target-less", i.e. they just free something, but not in a - * specific place. I.e., __get_free_pages() can't do anything to free - * *adjacent* pages :-( This situation becomes even worse for DMA memory, - * since the freeing algorithms are also blind to DMA capability of pages. - */ - -/* 1998-10-20: ++andreas - unswap_by_move disabled because it does not handle swapped shm pages. -*/ - -/* 2000-05-01: ++andreas - Integrated with bootmem. Remove all traces of unswap_by_move. -*/ - -#ifdef CONFIG_STRAM_SWAP -#define ALIGN_IF_SWAP(x) PAGE_ALIGN(x) -#else -#define ALIGN_IF_SWAP(x) (x) -#endif - -/* get index of swap page at address 'addr' */ -#define SWAP_NR(addr) (((addr) - swap_start) >> PAGE_SHIFT) - -/* get address of swap page #'nr' */ -#define SWAP_ADDR(nr) (swap_start + ((nr) << PAGE_SHIFT)) - -/* get number of pages for 'n' bytes (already page-aligned) */ -#define N_PAGES(n) ((n) >> PAGE_SHIFT) - -/* The following two numbers define the maximum fraction of ST-RAM in total - * memory, below that the kernel would automatically use ST-RAM as swap - * space. This decision can be overridden with stram_swap= */ -#define MAX_STRAM_FRACTION_NOM 1 -#define MAX_STRAM_FRACTION_DENOM 3 - /* Start and end (virtual) of ST-RAM */ static void *stram_start, *stram_end; @@ -164,10 +89,9 @@ typedef struct stram_block { } BLOCK; /* values for flags field */ -#define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */ +#define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */ #define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */ -#define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */ -#define BLOCK_INSWAP 0x10 /* block allocated in swap space */ +#define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */ /* list of allocated blocks */ static BLOCK *alloc_list; @@ -179,60 +103,8 @@ static BLOCK *alloc_list; #define N_STATIC_BLOCKS 20 static BLOCK static_blocks[N_STATIC_BLOCKS]; -#ifdef CONFIG_STRAM_SWAP -/* max. number of bytes to use for swapping - * 0 = no ST-RAM swapping - * -1 = do swapping (to whole ST-RAM) if it's less than MAX_STRAM_FRACTION of - * total memory - */ -static int max_swap_size = -1; - -/* start and end of swapping area */ -static void *swap_start, *swap_end; - -/* The ST-RAM's swap info structure */ -static struct swap_info_struct *stram_swap_info; - -/* The ST-RAM's swap type */ -static int stram_swap_type; - -/* Semaphore for get_stram_region. */ -static DECLARE_MUTEX(stram_swap_sem); - -/* major and minor device number of the ST-RAM device; for the major, we use - * the same as Amiga z2ram, which is really similar and impossible on Atari, - * and for the minor a relatively odd number to avoid the user creating and - * using that device. */ -#define STRAM_MAJOR Z2RAM_MAJOR -#define STRAM_MINOR 13 - -/* Some impossible pointer value */ -#define MAGIC_FILE_P (struct file *)0xffffdead - -#ifdef DO_PROC -static unsigned stat_swap_read; -static unsigned stat_swap_write; -static unsigned stat_swap_force; -#endif /* DO_PROC */ - -#endif /* CONFIG_STRAM_SWAP */ - /***************************** Prototypes *****************************/ -#ifdef CONFIG_STRAM_SWAP -static int swap_init(void *start_mem, void *swap_data); -static void *get_stram_region( unsigned long n_pages ); -static void free_stram_region( unsigned long offset, unsigned long n_pages - ); -static int in_some_region(void *addr); -static unsigned long find_free_region( unsigned long n_pages, unsigned long - *total_free, unsigned long - *region_free ); -static void do_stram_request(request_queue_t *); -static int stram_open( struct inode *inode, struct file *filp ); -static int stram_release( struct inode *inode, struct file *filp ); -static void reserve_region(void *start, void *end); -#endif static BLOCK *add_region( void *addr, unsigned long size ); static BLOCK *find_region( void *addr ); static int remove_region( BLOCK *block ); @@ -279,84 +151,11 @@ void __init atari_stram_init(void) */ void __init atari_stram_reserve_pages(void *start_mem) { -#ifdef CONFIG_STRAM_SWAP - /* if max_swap_size is negative (i.e. no stram_swap= option given), - * determine at run time whether to use ST-RAM swapping */ - if (max_swap_size < 0) - /* Use swapping if ST-RAM doesn't make up more than MAX_STRAM_FRACTION - * of total memory. In that case, the max. size is set to 16 MB, - * because ST-RAM can never be bigger than that. - * Also, never use swapping on a Hades, there's no separate ST-RAM in - * that machine. */ - max_swap_size = - (!MACH_IS_HADES && - (N_PAGES(stram_end-stram_start)*MAX_STRAM_FRACTION_DENOM <= - ((unsigned long)high_memory>>PAGE_SHIFT)*MAX_STRAM_FRACTION_NOM)) ? 16*1024*1024 : 0; - DPRINTK( "atari_stram_reserve_pages: max_swap_size = %d\n", max_swap_size ); -#endif - /* always reserve first page of ST-RAM, the first 2 kB are * supervisor-only! */ if (!kernel_in_stram) reserve_bootmem (0, PAGE_SIZE); -#ifdef CONFIG_STRAM_SWAP - { - void *swap_data; - - start_mem = (void *) PAGE_ALIGN ((unsigned long) start_mem); - /* determine first page to use as swap: if the kernel is - in TT-RAM, this is the first page of (usable) ST-RAM; - otherwise just use the end of kernel data (= start_mem) */ - swap_start = !kernel_in_stram ? stram_start + PAGE_SIZE : start_mem; - /* decrement by one page, rest of kernel assumes that first swap page - * is always reserved and maybe doesn't handle swp_entry == 0 - * correctly */ - swap_start -= PAGE_SIZE; - swap_end = stram_end; - if (swap_end-swap_start > max_swap_size) - swap_end = swap_start + max_swap_size; - DPRINTK( "atari_stram_reserve_pages: swapping enabled; " - "swap=%p-%p\n", swap_start, swap_end); - - /* reserve some amount of memory for maintainance of - * swapping itself: one page for each 2048 (PAGE_SIZE/2) - * swap pages. (2 bytes for each page) */ - swap_data = start_mem; - start_mem += ((SWAP_NR(swap_end) + PAGE_SIZE/2 - 1) - >> (PAGE_SHIFT-1)) << PAGE_SHIFT; - /* correct swap_start if necessary */ - if (swap_start + PAGE_SIZE == swap_data) - swap_start = start_mem - PAGE_SIZE; - - if (!swap_init( start_mem, swap_data )) { - printk( KERN_ERR "ST-RAM swap space initialization failed\n" ); - max_swap_size = 0; - return; - } - /* reserve region for swapping meta-data */ - reserve_region(swap_data, start_mem); - /* reserve swapping area itself */ - reserve_region(swap_start + PAGE_SIZE, swap_end); - - /* - * If the whole ST-RAM is used for swapping, there are no allocatable - * dma pages left. But unfortunately, some shared parts of the kernel - * (particularly the SCSI mid-level) call __get_dma_pages() - * unconditionally :-( These calls then fail, and scsi.c even doesn't - * check for NULL return values and just crashes. The quick fix for - * this (instead of doing much clean up work in the SCSI code) is to - * pretend all pages are DMA-able by setting mach_max_dma_address to - * ULONG_MAX. This doesn't change any functionality so far, since - * get_dma_pages() shouldn't be used on Atari anyway anymore (better - * use atari_stram_alloc()), and the Atari SCSI drivers don't need DMA - * memory. But unfortunately there's now no kind of warning (even not - * a NULL return value) if you use get_dma_pages() nevertheless :-( - * You just will get non-DMA-able memory... - */ - mach_max_dma_address = 0xffffffff; - } -#endif } void atari_stram_mem_init_hook (void) @@ -367,7 +166,6 @@ void atari_stram_mem_init_hook (void) /* * This is main public interface: somehow allocate a ST-RAM block - * There are three strategies: * * - If we're before mem_init(), we have to make a static allocation. The * region is taken in the kernel data area (if the kernel is in ST-RAM) or @@ -375,14 +173,9 @@ void atari_stram_mem_init_hook (void) * rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel * address space in the latter case. * - * - If mem_init() already has been called and ST-RAM swapping is enabled, - * try to get the memory from the (pseudo) swap-space, either free already - * or by moving some other pages out of the swap. - * - * - If mem_init() already has been called, and ST-RAM swapping is not - * enabled, the only possibility is to try with __get_dma_pages(). This has - * the disadvantage that it's very hard to get more than 1 page, and it is - * likely to fail :-( + * - If mem_init() already has been called, try with __get_dma_pages(). + * This has the disadvantage that it's very hard to get more than 1 page, + * and it is likely to fail :-( * */ void *atari_stram_alloc(long size, const char *owner) @@ -393,27 +186,13 @@ void *atari_stram_alloc(long size, const char *owner) DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner); - size = ALIGN_IF_SWAP(size); - DPRINTK( "atari_stram_alloc: rounded size = %08lx\n", size ); -#ifdef CONFIG_STRAM_SWAP - if (max_swap_size) { - /* If swapping is active: make some free space in the swap - "device". */ - DPRINTK( "atari_stram_alloc: after mem_init, swapping ok, " - "calling get_region\n" ); - addr = get_stram_region( N_PAGES(size) ); - flags = BLOCK_INSWAP; - } - else -#endif if (!mem_init_done) return alloc_bootmem_low(size); else { - /* After mem_init() and no swapping: can only resort to - * __get_dma_pages() */ + /* After mem_init(): can only resort to __get_dma_pages() */ addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size)); flags = BLOCK_GFP; - DPRINTK( "atari_stram_alloc: after mem_init, swapping off, " + DPRINTK( "atari_stram_alloc: after mem_init, " "get_pages=%p\n", addr ); } @@ -422,12 +201,7 @@ void *atari_stram_alloc(long size, const char *owner) /* out of memory for BLOCK structure :-( */ DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- " "freeing again\n" ); -#ifdef CONFIG_STRAM_SWAP - if (flags == BLOCK_INSWAP) - free_stram_region( SWAP_NR(addr), N_PAGES(size) ); - else -#endif - free_pages((unsigned long)addr, get_order(size)); + free_pages((unsigned long)addr, get_order(size)); return( NULL ); } block->owner = owner; @@ -451,25 +225,12 @@ void atari_stram_free( void *addr ) DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, " "flags=%02x\n", block, block->size, block->owner, block->flags ); -#ifdef CONFIG_STRAM_SWAP - if (!max_swap_size) { -#endif - if (block->flags & BLOCK_GFP) { - DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n", - get_order(block->size)); - free_pages((unsigned long)addr, get_order(block->size)); - } - else - goto fail; -#ifdef CONFIG_STRAM_SWAP - } - else if (block->flags & BLOCK_INSWAP) { - DPRINTK( "atari_stram_free: is swap-alloced\n" ); - free_stram_region( SWAP_NR(block->start), N_PAGES(block->size) ); - } - else + if (!(block->flags & BLOCK_GFP)) goto fail; -#endif + + DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n", + get_order(block->size)); + free_pages((unsigned long)addr, get_order(block->size)); remove_region( block ); return; @@ -478,612 +239,6 @@ void atari_stram_free( void *addr ) "(called from %p)\n", addr, __builtin_return_address(0) ); } - -#ifdef CONFIG_STRAM_SWAP - - -/* ------------------------------------------------------------------------ */ -/* Main Swapping Functions */ -/* ------------------------------------------------------------------------ */ - - -/* - * Initialize ST-RAM swap device - * (lots copied and modified from sys_swapon() in mm/swapfile.c) - */ -static int __init swap_init(void *start_mem, void *swap_data) -{ - static struct dentry fake_dentry; - static struct vfsmount fake_vfsmnt; - struct swap_info_struct *p; - struct inode swap_inode; - unsigned int type; - void *addr; - int i, j, k, prev; - - DPRINTK("swap_init(start_mem=%p, swap_data=%p)\n", - start_mem, swap_data); - - /* need at least one page for swapping to (and this also isn't very - * much... :-) */ - if (swap_end - swap_start < 2*PAGE_SIZE) { - printk( KERN_WARNING "stram_swap_init: swap space too small\n" ); - return( 0 ); - } - - /* find free slot in swap_info */ - for( p = swap_info, type = 0; type < nr_swapfiles; type++, p++ ) - if (!(p->flags & SWP_USED)) - break; - if (type >= MAX_SWAPFILES) { - printk( KERN_WARNING "stram_swap_init: max. number of " - "swap devices exhausted\n" ); - return( 0 ); - } - if (type >= nr_swapfiles) - nr_swapfiles = type+1; - - stram_swap_info = p; - stram_swap_type = type; - - /* fake some dir cache entries to give us some name in /dev/swaps */ - fake_dentry.d_parent = &fake_dentry; - fake_dentry.d_name.name = "stram (internal)"; - fake_dentry.d_name.len = 16; - fake_vfsmnt.mnt_parent = &fake_vfsmnt; - - p->flags = SWP_USED; - p->swap_file = &fake_dentry; - p->swap_vfsmnt = &fake_vfsmnt; - p->swap_map = swap_data; - p->cluster_nr = 0; - p->next = -1; - p->prio = 0x7ff0; /* a rather high priority, but not the higest - * to give the user a chance to override */ - - /* call stram_open() directly, avoids at least the overhead in - * constructing a dummy file structure... */ - swap_inode.i_rdev = MKDEV( STRAM_MAJOR, STRAM_MINOR ); - stram_open( &swap_inode, MAGIC_FILE_P ); - p->max = SWAP_NR(swap_end); - - /* initialize swap_map: set regions that are already allocated or belong - * to kernel data space to SWAP_MAP_BAD, otherwise to free */ - j = 0; /* # of free pages */ - k = 0; /* # of already allocated pages (from pre-mem_init stram_alloc()) */ - p->lowest_bit = 0; - p->highest_bit = 0; - for( i = 1, addr = SWAP_ADDR(1); i < p->max; - i++, addr += PAGE_SIZE ) { - if (in_some_region( addr )) { - p->swap_map[i] = SWAP_MAP_BAD; - ++k; - } - else if (kernel_in_stram && addr < start_mem ) { - p->swap_map[i] = SWAP_MAP_BAD; - } - else { - p->swap_map[i] = 0; - ++j; - if (!p->lowest_bit) p->lowest_bit = i; - p->highest_bit = i; - } - } - /* first page always reserved (and doesn't really belong to swap space) */ - p->swap_map[0] = SWAP_MAP_BAD; - - /* now swapping to this device ok */ - p->pages = j + k; - swap_list_lock(); - nr_swap_pages += j; - p->flags = SWP_WRITEOK; - - /* insert swap space into swap_list */ - prev = -1; - for (i = swap_list.head; i >= 0; i = swap_info[i].next) { - if (p->prio >= swap_info[i].prio) { - break; - } - prev = i; - } - p->next = i; - if (prev < 0) { - swap_list.head = swap_list.next = p - swap_info; - } else { - swap_info[prev].next = p - swap_info; - } - swap_list_unlock(); - - printk( KERN_INFO "Using %dk (%d pages) of ST-RAM as swap space.\n", - p->pages << 2, p->pages ); - return( 1 ); -} - - -/* - * The swap entry has been read in advance, and we return 1 to indicate - * that the page has been used or is no longer needed. - * - * Always set the resulting pte to be nowrite (the same as COW pages - * after one process has exited). We don't know just how many PTEs will - * share this swap entry, so be cautious and let do_wp_page work out - * what to do if a write is requested later. - */ -static inline void unswap_pte(struct vm_area_struct * vma, unsigned long - address, pte_t *dir, swp_entry_t entry, - struct page *page) -{ - pte_t pte = *dir; - - if (pte_none(pte)) - return; - if (pte_present(pte)) { - /* If this entry is swap-cached, then page must already - hold the right address for any copies in physical - memory */ - if (pte_page(pte) != page) - return; - /* We will be removing the swap cache in a moment, so... */ - set_pte(dir, pte_mkdirty(pte)); - return; - } - if (pte_val(pte) != entry.val) - return; - - DPRINTK("unswap_pte: replacing entry %08lx by new page %p", - entry.val, page); - set_pte(dir, pte_mkdirty(mk_pte(page, vma->vm_page_prot))); - swap_free(entry); - get_page(page); - inc_mm_counter(vma->vm_mm, rss); -} - -static inline void unswap_pmd(struct vm_area_struct * vma, pmd_t *dir, - unsigned long address, unsigned long size, - unsigned long offset, swp_entry_t entry, - struct page *page) -{ - pte_t * pte; - unsigned long end; - - if (pmd_none(*dir)) - return; - if (pmd_bad(*dir)) { - pmd_ERROR(*dir); - pmd_clear(dir); - return; - } - pte = pte_offset_kernel(dir, address); - offset += address & PMD_MASK; - address &= ~PMD_MASK; - end = address + size; - if (end > PMD_SIZE) - end = PMD_SIZE; - do { - unswap_pte(vma, offset+address-vma->vm_start, pte, entry, page); - address += PAGE_SIZE; - pte++; - } while (address < end); -} - -static inline void unswap_pgd(struct vm_area_struct * vma, pgd_t *dir, - unsigned long address, unsigned long size, - swp_entry_t entry, struct page *page) -{ - pmd_t * pmd; - unsigned long offset, end; - - if (pgd_none(*dir)) - return; - if (pgd_bad(*dir)) { - pgd_ERROR(*dir); - pgd_clear(dir); - return; - } - pmd = pmd_offset(dir, address); - offset = address & PGDIR_MASK; - address &= ~PGDIR_MASK; - end = address + size; - if (end > PGDIR_SIZE) - end = PGDIR_SIZE; - do { - unswap_pmd(vma, pmd, address, end - address, offset, entry, - page); - address = (address + PMD_SIZE) & PMD_MASK; - pmd++; - } while (address < end); -} - -static void unswap_vma(struct vm_area_struct * vma, pgd_t *pgdir, - swp_entry_t entry, struct page *page) -{ - unsigned long start = vma->vm_start, end = vma->vm_end; - - do { - unswap_pgd(vma, pgdir, start, end - start, entry, page); - start = (start + PGDIR_SIZE) & PGDIR_MASK; - pgdir++; - } while (start < end); -} - -static void unswap_process(struct mm_struct * mm, swp_entry_t entry, - struct page *page) -{ - struct vm_area_struct* vma; - - /* - * Go through process' page directory. - */ - if (!mm) - return; - for (vma = mm->mmap; vma; vma = vma->vm_next) { - pgd_t * pgd = pgd_offset(mm, vma->vm_start); - unswap_vma(vma, pgd, entry, page); - } -} - - -static int unswap_by_read(unsigned short *map, unsigned long max, - unsigned long start, unsigned long n_pages) -{ - struct task_struct *p; - struct page *page; - swp_entry_t entry; - unsigned long i; - - DPRINTK( "unswapping %lu..%lu by reading in\n", - start, start+n_pages-1 ); - - for( i = start; i < start+n_pages; ++i ) { - if (map[i] == SWAP_MAP_BAD) { - printk( KERN_ERR "get_stram_region: page %lu already " - "reserved??\n", i ); - continue; - } - - if (map[i]) { - entry = swp_entry(stram_swap_type, i); - DPRINTK("unswap: map[i=%lu]=%u nr_swap=%ld\n", - i, map[i], nr_swap_pages); - - swap_device_lock(stram_swap_info); - map[i]++; - swap_device_unlock(stram_swap_info); - /* Get a page for the entry, using the existing - swap cache page if there is one. Otherwise, - get a clean page and read the swap into it. */ - page = read_swap_cache_async(entry, NULL, 0); - if (!page) { - swap_free(entry); - return -ENOMEM; - } - read_lock(&tasklist_lock); - for_each_process(p) - unswap_process(p->mm, entry, page); - read_unlock(&tasklist_lock); - shmem_unuse(entry, page); - /* Now get rid of the extra reference to the - temporary page we've been using. */ - if (PageSwapCache(page)) - delete_from_swap_cache(page); - __free_page(page); - #ifdef DO_PROC - stat_swap_force++; - #endif - } - - DPRINTK( "unswap: map[i=%lu]=%u nr_swap=%ld\n", - i, map[i], nr_swap_pages ); - swap_list_lock(); - swap_device_lock(stram_swap_info); - map[i] = SWAP_MAP_BAD; - if (stram_swap_info->lowest_bit == i) - stram_swap_info->lowest_bit++; - if (stram_swap_info->highest_bit == i) - stram_swap_info->highest_bit--; - --nr_swap_pages; - swap_device_unlock(stram_swap_info); - swap_list_unlock(); - } - - return 0; -} - -/* - * reserve a region in ST-RAM swap space for an allocation - */ -static void *get_stram_region( unsigned long n_pages ) -{ - unsigned short *map = stram_swap_info->swap_map; - unsigned long max = stram_swap_info->max; - unsigned long start, total_free, region_free; - int err; - void *ret = NULL; - - DPRINTK( "get_stram_region(n_pages=%lu)\n", n_pages ); - - down(&stram_swap_sem); - - /* disallow writing to the swap device now */ - stram_swap_info->flags = SWP_USED; - - /* find a region of n_pages pages in the swap space including as much free - * pages as possible (and excluding any already-reserved pages). */ - if (!(start = find_free_region( n_pages, &total_free, ®ion_free ))) - goto end; - DPRINTK( "get_stram_region: region starts at %lu, has %lu free pages\n", - start, region_free ); - - err = unswap_by_read(map, max, start, n_pages); - if (err) - goto end; - - ret = SWAP_ADDR(start); - end: - /* allow using swap device again */ - stram_swap_info->flags = SWP_WRITEOK; - up(&stram_swap_sem); - DPRINTK( "get_stram_region: returning %p\n", ret ); - return( ret ); -} - - -/* - * free a reserved region in ST-RAM swap space - */ -static void free_stram_region( unsigned long offset, unsigned long n_pages ) -{ - unsigned short *map = stram_swap_info->swap_map; - - DPRINTK( "free_stram_region(offset=%lu,n_pages=%lu)\n", offset, n_pages ); - - if (offset < 1 || offset + n_pages > stram_swap_info->max) { - printk( KERN_ERR "free_stram_region: Trying to free non-ST-RAM\n" ); - return; - } - - swap_list_lock(); - swap_device_lock(stram_swap_info); - /* un-reserve the freed pages */ - for( ; n_pages > 0; ++offset, --n_pages ) { - if (map[offset] != SWAP_MAP_BAD) - printk( KERN_ERR "free_stram_region: Swap page %lu was not " - "reserved\n", offset ); - map[offset] = 0; - } - - /* update swapping meta-data */ - if (offset < stram_swap_info->lowest_bit) - stram_swap_info->lowest_bit = offset; - if (offset+n_pages-1 > stram_swap_info->highest_bit) - stram_swap_info->highest_bit = offset+n_pages-1; - if (stram_swap_info->prio > swap_info[swap_list.next].prio) - swap_list.next = swap_list.head; - nr_swap_pages += n_pages; - swap_device_unlock(stram_swap_info); - swap_list_unlock(); -} - - -/* ------------------------------------------------------------------------ */ -/* Utility Functions for Swapping */ -/* ------------------------------------------------------------------------ */ - - -/* is addr in some of the allocated regions? */ -static int in_some_region(void *addr) -{ - BLOCK *p; - - for( p = alloc_list; p; p = p->next ) { - if (p->start <= addr && addr < p->start + p->size) - return( 1 ); - } - return( 0 ); -} - - -static unsigned long find_free_region(unsigned long n_pages, - unsigned long *total_free, - unsigned long *region_free) -{ - unsigned short *map = stram_swap_info->swap_map; - unsigned long max = stram_swap_info->max; - unsigned long head, tail, max_start; - long nfree, max_free; - - /* first scan the swap space for a suitable place for the allocation */ - head = 1; - max_start = 0; - max_free = -1; - *total_free = 0; - - start_over: - /* increment tail until final window size reached, and count free pages */ - nfree = 0; - for( tail = head; tail-head < n_pages && tail < max; ++tail ) { - if (map[tail] == SWAP_MAP_BAD) { - head = tail+1; - goto start_over; - } - if (!map[tail]) { - ++nfree; - ++*total_free; - } - } - if (tail-head < n_pages) - goto out; - if (nfree > max_free) { - max_start = head; - max_free = nfree; - if (max_free >= n_pages) - /* don't need more free pages... :-) */ - goto out; - } - - /* now shift the window and look for the area where as much pages as - * possible are free */ - while( tail < max ) { - nfree -= (map[head++] == 0); - if (map[tail] == SWAP_MAP_BAD) { - head = tail+1; - goto start_over; - } - if (!map[tail]) { - ++nfree; - ++*total_free; - } - ++tail; - if (nfree > max_free) { - max_start = head; - max_free = nfree; - if (max_free >= n_pages) - /* don't need more free pages... :-) */ - goto out; - } - } - - out: - if (max_free < 0) { - printk( KERN_NOTICE "get_stram_region: ST-RAM too full or fragmented " - "-- can't allocate %lu pages\n", n_pages ); - return( 0 ); - } - - *region_free = max_free; - return( max_start ); -} - - -/* setup parameters from command line */ -void __init stram_swap_setup(char *str, int *ints) -{ - if (ints[0] >= 1) - max_swap_size = ((ints[1] < 0 ? 0 : ints[1]) * 1024) & PAGE_MASK; -} - - -/* ------------------------------------------------------------------------ */ -/* ST-RAM device */ -/* ------------------------------------------------------------------------ */ - -static int refcnt; - -static void do_stram_request(request_queue_t *q) -{ - struct request *req; - - while ((req = elv_next_request(q)) != NULL) { - void *start = swap_start + (req->sector << 9); - unsigned long len = req->current_nr_sectors << 9; - if ((start + len) > swap_end) { - printk( KERN_ERR "stram: bad access beyond end of device: " - "block=%ld, count=%d\n", - req->sector, - req->current_nr_sectors ); - end_request(req, 0); - continue; - } - - if (req->cmd == READ) { - memcpy(req->buffer, start, len); -#ifdef DO_PROC - stat_swap_read += N_PAGES(len); -#endif - } - else { - memcpy(start, req->buffer, len); -#ifdef DO_PROC - stat_swap_write += N_PAGES(len); -#endif - } - end_request(req, 1); - } -} - - -static int stram_open( struct inode *inode, struct file *filp ) -{ - if (filp != MAGIC_FILE_P) { - printk( KERN_NOTICE "Only kernel can open ST-RAM device\n" ); - return( -EPERM ); - } - if (refcnt) - return( -EBUSY ); - ++refcnt; - return( 0 ); -} - -static int stram_release( struct inode *inode, struct file *filp ) -{ - if (filp != MAGIC_FILE_P) { - printk( KERN_NOTICE "Only kernel can close ST-RAM device\n" ); - return( -EPERM ); - } - if (refcnt > 0) - --refcnt; - return( 0 ); -} - - -static struct block_device_operations stram_fops = { - .open = stram_open, - .release = stram_release, -}; - -static struct gendisk *stram_disk; -static struct request_queue *stram_queue; -static DEFINE_SPINLOCK(stram_lock); - -int __init stram_device_init(void) -{ - if (!MACH_IS_ATARI) - /* no point in initializing this, I hope */ - return -ENXIO; - - if (!max_swap_size) - /* swapping not enabled */ - return -ENXIO; - stram_disk = alloc_disk(1); - if (!stram_disk) - return -ENOMEM; - - if (register_blkdev(STRAM_MAJOR, "stram")) { - put_disk(stram_disk); - return -ENXIO; - } - - stram_queue = blk_init_queue(do_stram_request, &stram_lock); - if (!stram_queue) { - unregister_blkdev(STRAM_MAJOR, "stram"); - put_disk(stram_disk); - return -ENOMEM; - } - - stram_disk->major = STRAM_MAJOR; - stram_disk->first_minor = STRAM_MINOR; - stram_disk->fops = &stram_fops; - stram_disk->queue = stram_queue; - sprintf(stram_disk->disk_name, "stram"); - set_capacity(stram_disk, (swap_end - swap_start)/512); - add_disk(stram_disk); - return 0; -} - - - -/* ------------------------------------------------------------------------ */ -/* Misc Utility Functions */ -/* ------------------------------------------------------------------------ */ - -/* reserve a range of pages */ -static void reserve_region(void *start, void *end) -{ - reserve_bootmem (virt_to_phys(start), end - start); -} - -#endif /* CONFIG_STRAM_SWAP */ - /* ------------------------------------------------------------------------ */ /* Region Management */ @@ -1173,50 +328,9 @@ int get_stram_list( char *buf ) { int len = 0; BLOCK *p; -#ifdef CONFIG_STRAM_SWAP - int i; - unsigned short *map = stram_swap_info->swap_map; - unsigned long max = stram_swap_info->max; - unsigned free = 0, used = 0, rsvd = 0; -#endif -#ifdef CONFIG_STRAM_SWAP - if (max_swap_size) { - for( i = 1; i < max; ++i ) { - if (!map[i]) - ++free; - else if (map[i] == SWAP_MAP_BAD) - ++rsvd; - else - ++used; - } - PRINT_PROC( - "Total ST-RAM: %8u kB\n" - "Total ST-RAM swap: %8lu kB\n" - "Free swap: %8u kB\n" - "Used swap: %8u kB\n" - "Allocated swap: %8u kB\n" - "Swap Reads: %8u\n" - "Swap Writes: %8u\n" - "Swap Forced Reads: %8u\n", - (stram_end - stram_start) >> 10, - (max-1) << (PAGE_SHIFT-10), - free << (PAGE_SHIFT-10), - used << (PAGE_SHIFT-10), - rsvd << (PAGE_SHIFT-10), - stat_swap_read, - stat_swap_write, - stat_swap_force ); - } - else { -#endif - PRINT_PROC( "ST-RAM swapping disabled\n" ); - PRINT_PROC("Total ST-RAM: %8u kB\n", + PRINT_PROC("Total ST-RAM: %8u kB\n", (stram_end - stram_start) >> 10); -#ifdef CONFIG_STRAM_SWAP - } -#endif - PRINT_PROC( "Allocated regions:\n" ); for( p = alloc_list; p; p = p->next ) { if (len + 50 >= PAGE_SIZE) @@ -1227,8 +341,6 @@ int get_stram_list( char *buf ) p->owner); if (p->flags & BLOCK_GFP) PRINT_PROC( "page-alloced)\n" ); - else if (p->flags & BLOCK_INSWAP) - PRINT_PROC( "in swap)\n" ); else PRINT_PROC( "??)\n" ); } |
