#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>
#include <asm/io.h>
#include <asm/semaphore.h>
-#include <linux/swapops.h>
-
#undef DEBUG
#ifdef DEBUG
#include <linux/proc_fs.h>
#endif
-/* Pre-swapping comments:
- *
+/*
* ++roman:
*
* New version of ST-Ram buffer allocation. Instead of using the
*
*/
-/*
- * 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;
} 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;
#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 );
*/
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)
/*
* 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
* 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)
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 );
}
/* 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;
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;
"(called from %p)\n", addr, __builtin_return_address(0) );
}
-
-#ifdef CONFIG_STRAM_SWAP
-
-\f
-/* ------------------------------------------------------------------------ */
-/* 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();
-}
-
-\f
-/* ------------------------------------------------------------------------ */
-/* 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;
-}
-
-\f
-/* ------------------------------------------------------------------------ */
-/* 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;
-}
-
-
-\f
-/* ------------------------------------------------------------------------ */
-/* 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 */
-
\f
/* ------------------------------------------------------------------------ */
/* Region Management */
{
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)
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" );
}
git://git.onelab.eu / linux-2.6.git / blobdiff