[PATCH] mm: m68k kill stram swap

Please, please now delete the Atari CONFIG_STRAM_SWAP code.  It may be
excellent and ingenious code, but its reference to swap_vfsmnt betrays that it
hasn't been built since 2.5.1 (four years old come December), it's delving
deep into matters which are the preserve of core mm code, its only purpose is
to give the more conscientious mm guys an anxiety attack from time to time;
yet we keep on breaking it more and more.

If you want to use RAM for swap, then if the MTD driver does not already
provide just what you need, I'm sure David could be persuaded to add the
extra.  But you'd also like to be able to allocate extents of that swap for
other use: we can give you a core interface for that if you need.  But unbuilt
for four years suggests to me that there's no need at all.

I cannot swear the patch below won't break your build, but believe so.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Documentation/kernel-parameters.txt

@@ -1460,8 +1460,6 @@ running once the system is up.
 	stifb=		[HW]
 			Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
 
-	stram_swap=	[HW,M68k]
-
 	swiotlb=	[IA-64] Number of I/O TLB slabs
 
 	switches=	[HW,M68k]

Documentation/m68k/kernel-options.txt

@@ -626,7 +626,7 @@ ignored (others aren't affected).
     can be performed in optimal order. Not all SCSI devices support
     tagged queuing (:-().
 
-4.6 switches=
+4.5 switches=
 -------------
 
 Syntax: switches=<list of switches>
@@ -661,28 +661,6 @@ correctly.
 earlier initialization ("ov_"-less) takes precedence. But the
 switching-off on reset still happens in this case.
 
-4.5) stram_swap=
-----------------
-
-Syntax: stram_swap=<do_swap>[,<max_swap>]
-
-  This option is available only if the kernel has been compiled with
-CONFIG_STRAM_SWAP enabled. Normally, the kernel then determines
-dynamically whether to actually use ST-RAM as swap space. (Currently,
-the fraction of ST-RAM must be less or equal 1/3 of total memory to
-enable this swapping.) You can override the kernel's decision by
-specifying this option. 1 for <do_swap> means always enable the swap,
-even if you have less alternate RAM. 0 stands for never swap to
-ST-RAM, even if it's small enough compared to the rest of memory.
-
-  If ST-RAM swapping is enabled, the kernel usually uses all free
-ST-RAM as swap "device". If the kernel resides in ST-RAM, the region
-allocated by it is obviously never used for swapping :-) You can also
-limit this amount by specifying the second parameter, <max_swap>, if
-you want to use parts of ST-RAM as normal system memory. <max_swap> is
-in kBytes and the number should be a multiple of 4 (otherwise: rounded
-down).
-
 5) Options for Amiga Only:
 ==========================
 

arch/m68k/Kconfig

@@ -388,33 +388,11 @@ config AMIGA_PCMCIA
 	  Include support in the kernel for pcmcia on Amiga 1200 and Amiga
 	  600. If you intend to use pcmcia cards say Y; otherwise say N.
 
-config STRAM_SWAP
-	bool "Support for ST-RAM as swap space"
-	depends on ATARI && BROKEN
-	---help---
-	  Some Atari 68k machines (including the 520STF and 1020STE) divide
-	  their addressable memory into ST and TT sections.  The TT section
-	  (up to 512MB) is the main memory; the ST section (up to 4MB) is
-	  accessible to the built-in graphics board, runs slower, and is
-	  present mainly for backward compatibility with older machines.
-
-	  This enables support for using (parts of) ST-RAM as swap space,
-	  instead of as normal system memory. This can first enhance system
-	  performance if you have lots of alternate RAM (compared to the size
-	  of ST-RAM), because executable code always will reside in faster
-	  memory. ST-RAM will remain as ultra-fast swap space. On the other
-	  hand, it allows much improved dynamic allocations of ST-RAM buffers
-	  for device driver modules (e.g. floppy, ACSI, SLM printer, DMA
-	  sound). The probability that such allocations at module load time
-	  fail is drastically reduced.
-
 config STRAM_PROC
 	bool "ST-RAM statistics in /proc"
 	depends on ATARI
 	help
-	  Say Y here to report ST-RAM usage statistics in /proc/stram.  See
-	  the help for CONFIG_STRAM_SWAP for discussion of ST-RAM and its
-	  uses.
+	  Say Y here to report ST-RAM usage statistics in /proc/stram.
 
 config HEARTBEAT
 	bool "Use power LED as a heartbeat" if AMIGA || APOLLO || ATARI || MAC ||Q40

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;
 
@@ -167,7 +92,6 @@ typedef struct stram_block {
 #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 */
 
 /* 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 );
 	}
 
@@ -422,11 +201,6 @@ 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));
 			return( NULL );
 		}
@@ -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) {
+	if (!(block->flags & BLOCK_GFP))
+		goto fail;
+
 	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
-		goto fail;
-#endif
 	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, &region_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",
 			   (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" );
 	}