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authorPaul Mackerras <paulus@samba.org>2005-10-30 21:37:12 -0500
committerPaul Mackerras <paulus@samba.org>2005-10-30 21:37:12 -0500
commit23fd07750a789a66fe88cf173d52a18f1a387da4 (patch)
tree06fdd6df35fdb835abdaa9b754d62f6b84b97250 /arch/m68k/atari/stram.c
parentbd787d438a59266af3c9f6351644c85ef1dd21fe (diff)
parented28f96ac1960f30f818374d65be71d2fdf811b0 (diff)
Merge ../linux-2.6 by hand
Diffstat (limited to 'arch/m68k/atari/stram.c')
-rw-r--r--arch/m68k/atari/stram.c918
1 files changed, 15 insertions, 903 deletions
diff --git a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c
index 5a3c106b40c8..22e0481a5f7b 100644
--- a/arch/m68k/atari/stram.c
+++ b/arch/m68k/atari/stram.c
@@ -15,11 +15,9 @@
15#include <linux/kdev_t.h> 15#include <linux/kdev_t.h>
16#include <linux/major.h> 16#include <linux/major.h>
17#include <linux/init.h> 17#include <linux/init.h>
18#include <linux/swap.h>
19#include <linux/slab.h> 18#include <linux/slab.h>
20#include <linux/vmalloc.h> 19#include <linux/vmalloc.h>
21#include <linux/pagemap.h> 20#include <linux/pagemap.h>
22#include <linux/shm.h>
23#include <linux/bootmem.h> 21#include <linux/bootmem.h>
24#include <linux/mount.h> 22#include <linux/mount.h>
25#include <linux/blkdev.h> 23#include <linux/blkdev.h>
@@ -33,8 +31,6 @@
33#include <asm/io.h> 31#include <asm/io.h>
34#include <asm/semaphore.h> 32#include <asm/semaphore.h>
35 33
36#include <linux/swapops.h>
37
38#undef DEBUG 34#undef DEBUG
39 35
40#ifdef DEBUG 36#ifdef DEBUG
@@ -49,8 +45,7 @@
49#include <linux/proc_fs.h> 45#include <linux/proc_fs.h>
50#endif 46#endif
51 47
52/* Pre-swapping comments: 48/*
53 *
54 * ++roman: 49 * ++roman:
55 * 50 *
56 * New version of ST-Ram buffer allocation. Instead of using the 51 * New version of ST-Ram buffer allocation. Instead of using the
@@ -75,76 +70,6 @@
75 * 70 *
76 */ 71 */
77 72
78/*
79 * New Nov 1997: Use ST-RAM as swap space!
80 *
81 * In the past, there were often problems with modules that require ST-RAM
82 * buffers. Such drivers have to use __get_dma_pages(), which unfortunately
83 * often isn't very successful in allocating more than 1 page :-( [1] The net
84 * result was that most of the time you couldn't insmod such modules (ataflop,
85 * ACSI, SCSI on Falcon, Atari internal framebuffer, not to speak of acsi_slm,
86 * which needs a 1 MB buffer... :-).
87 *
88 * To overcome this limitation, ST-RAM can now be turned into a very
89 * high-speed swap space. If a request for an ST-RAM buffer comes, the kernel
90 * now tries to unswap some pages on that swap device to make some free (and
91 * contiguous) space. This works much better in comparison to
92 * __get_dma_pages(), since used swap pages can be selectively freed by either
93 * moving them to somewhere else in swap space, or by reading them back into
94 * system memory. Ok, there operation of unswapping isn't really cheap (for
95 * each page, one has to go through the page tables of all processes), but it
96 * doesn't happen that often (only when allocation ST-RAM, i.e. when loading a
97 * module that needs ST-RAM). But it at least makes it possible to load such
98 * modules!
99 *
100 * It could also be that overall system performance increases a bit due to
101 * ST-RAM swapping, since slow ST-RAM isn't used anymore for holding data or
102 * executing code in. It's then just a (very fast, compared to disk) back
103 * storage for not-so-often needed data. (But this effect must be compared
104 * with the loss of total memory...) Don't know if the effect is already
105 * visible on a TT, where the speed difference between ST- and TT-RAM isn't
106 * that dramatic, but it should on machines where TT-RAM is really much faster
107 * (e.g. Afterburner).
108 *
109 * [1]: __get_free_pages() does a fine job if you only want one page, but if
110 * you want more (contiguous) pages, it can give you such a block only if
111 * there's already a free one. The algorithm can't try to free buffers or swap
112 * out something in order to make more free space, since all that page-freeing
113 * mechanisms work "target-less", i.e. they just free something, but not in a
114 * specific place. I.e., __get_free_pages() can't do anything to free
115 * *adjacent* pages :-( This situation becomes even worse for DMA memory,
116 * since the freeing algorithms are also blind to DMA capability of pages.
117 */
118
119/* 1998-10-20: ++andreas
120 unswap_by_move disabled because it does not handle swapped shm pages.
121*/
122
123/* 2000-05-01: ++andreas
124 Integrated with bootmem. Remove all traces of unswap_by_move.
125*/
126
127#ifdef CONFIG_STRAM_SWAP
128#define ALIGN_IF_SWAP(x) PAGE_ALIGN(x)
129#else
130#define ALIGN_IF_SWAP(x) (x)
131#endif
132
133/* get index of swap page at address 'addr' */
134#define SWAP_NR(addr) (((addr) - swap_start) >> PAGE_SHIFT)
135
136/* get address of swap page #'nr' */
137#define SWAP_ADDR(nr) (swap_start + ((nr) << PAGE_SHIFT))
138
139/* get number of pages for 'n' bytes (already page-aligned) */
140#define N_PAGES(n) ((n) >> PAGE_SHIFT)
141
142/* The following two numbers define the maximum fraction of ST-RAM in total
143 * memory, below that the kernel would automatically use ST-RAM as swap
144 * space. This decision can be overridden with stram_swap= */
145#define MAX_STRAM_FRACTION_NOM 1
146#define MAX_STRAM_FRACTION_DENOM 3
147
148/* Start and end (virtual) of ST-RAM */ 73/* Start and end (virtual) of ST-RAM */
149static void *stram_start, *stram_end; 74static void *stram_start, *stram_end;
150 75
@@ -164,10 +89,9 @@ typedef struct stram_block {
164} BLOCK; 89} BLOCK;
165 90
166/* values for flags field */ 91/* values for flags field */
167#define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */ 92#define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */
168#define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */ 93#define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */
169#define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */ 94#define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */
170#define BLOCK_INSWAP 0x10 /* block allocated in swap space */
171 95
172/* list of allocated blocks */ 96/* list of allocated blocks */
173static BLOCK *alloc_list; 97static BLOCK *alloc_list;
@@ -179,60 +103,8 @@ static BLOCK *alloc_list;
179#define N_STATIC_BLOCKS 20 103#define N_STATIC_BLOCKS 20
180static BLOCK static_blocks[N_STATIC_BLOCKS]; 104static BLOCK static_blocks[N_STATIC_BLOCKS];
181 105
182#ifdef CONFIG_STRAM_SWAP
183/* max. number of bytes to use for swapping
184 * 0 = no ST-RAM swapping
185 * -1 = do swapping (to whole ST-RAM) if it's less than MAX_STRAM_FRACTION of
186 * total memory
187 */
188static int max_swap_size = -1;
189
190/* start and end of swapping area */
191static void *swap_start, *swap_end;
192
193/* The ST-RAM's swap info structure */
194static struct swap_info_struct *stram_swap_info;
195
196/* The ST-RAM's swap type */
197static int stram_swap_type;
198
199/* Semaphore for get_stram_region. */
200static DECLARE_MUTEX(stram_swap_sem);
201
202/* major and minor device number of the ST-RAM device; for the major, we use
203 * the same as Amiga z2ram, which is really similar and impossible on Atari,
204 * and for the minor a relatively odd number to avoid the user creating and
205 * using that device. */
206#define STRAM_MAJOR Z2RAM_MAJOR
207#define STRAM_MINOR 13
208
209/* Some impossible pointer value */
210#define MAGIC_FILE_P (struct file *)0xffffdead
211
212#ifdef DO_PROC
213static unsigned stat_swap_read;
214static unsigned stat_swap_write;
215static unsigned stat_swap_force;
216#endif /* DO_PROC */
217
218#endif /* CONFIG_STRAM_SWAP */
219
220/***************************** Prototypes *****************************/ 106/***************************** Prototypes *****************************/
221 107
222#ifdef CONFIG_STRAM_SWAP
223static int swap_init(void *start_mem, void *swap_data);
224static void *get_stram_region( unsigned long n_pages );
225static void free_stram_region( unsigned long offset, unsigned long n_pages
226 );
227static int in_some_region(void *addr);
228static unsigned long find_free_region( unsigned long n_pages, unsigned long
229 *total_free, unsigned long
230 *region_free );
231static void do_stram_request(request_queue_t *);
232static int stram_open( struct inode *inode, struct file *filp );
233static int stram_release( struct inode *inode, struct file *filp );
234static void reserve_region(void *start, void *end);
235#endif
236static BLOCK *add_region( void *addr, unsigned long size ); 108static BLOCK *add_region( void *addr, unsigned long size );
237static BLOCK *find_region( void *addr ); 109static BLOCK *find_region( void *addr );
238static int remove_region( BLOCK *block ); 110static int remove_region( BLOCK *block );
@@ -279,84 +151,11 @@ void __init atari_stram_init(void)
279 */ 151 */
280void __init atari_stram_reserve_pages(void *start_mem) 152void __init atari_stram_reserve_pages(void *start_mem)
281{ 153{
282#ifdef CONFIG_STRAM_SWAP
283 /* if max_swap_size is negative (i.e. no stram_swap= option given),
284 * determine at run time whether to use ST-RAM swapping */
285 if (max_swap_size < 0)
286 /* Use swapping if ST-RAM doesn't make up more than MAX_STRAM_FRACTION
287 * of total memory. In that case, the max. size is set to 16 MB,
288 * because ST-RAM can never be bigger than that.
289 * Also, never use swapping on a Hades, there's no separate ST-RAM in
290 * that machine. */
291 max_swap_size =
292 (!MACH_IS_HADES &&
293 (N_PAGES(stram_end-stram_start)*MAX_STRAM_FRACTION_DENOM <=
294 ((unsigned long)high_memory>>PAGE_SHIFT)*MAX_STRAM_FRACTION_NOM)) ? 16*1024*1024 : 0;
295 DPRINTK( "atari_stram_reserve_pages: max_swap_size = %d\n", max_swap_size );
296#endif
297
298 /* always reserve first page of ST-RAM, the first 2 kB are 154 /* always reserve first page of ST-RAM, the first 2 kB are
299 * supervisor-only! */ 155 * supervisor-only! */
300 if (!kernel_in_stram) 156 if (!kernel_in_stram)
301 reserve_bootmem (0, PAGE_SIZE); 157 reserve_bootmem (0, PAGE_SIZE);
302 158
303#ifdef CONFIG_STRAM_SWAP
304 {
305 void *swap_data;
306
307 start_mem = (void *) PAGE_ALIGN ((unsigned long) start_mem);
308 /* determine first page to use as swap: if the kernel is
309 in TT-RAM, this is the first page of (usable) ST-RAM;
310 otherwise just use the end of kernel data (= start_mem) */
311 swap_start = !kernel_in_stram ? stram_start + PAGE_SIZE : start_mem;
312 /* decrement by one page, rest of kernel assumes that first swap page
313 * is always reserved and maybe doesn't handle swp_entry == 0
314 * correctly */
315 swap_start -= PAGE_SIZE;
316 swap_end = stram_end;
317 if (swap_end-swap_start > max_swap_size)
318 swap_end = swap_start + max_swap_size;
319 DPRINTK( "atari_stram_reserve_pages: swapping enabled; "
320 "swap=%p-%p\n", swap_start, swap_end);
321
322 /* reserve some amount of memory for maintainance of
323 * swapping itself: one page for each 2048 (PAGE_SIZE/2)
324 * swap pages. (2 bytes for each page) */
325 swap_data = start_mem;
326 start_mem += ((SWAP_NR(swap_end) + PAGE_SIZE/2 - 1)
327 >> (PAGE_SHIFT-1)) << PAGE_SHIFT;
328 /* correct swap_start if necessary */
329 if (swap_start + PAGE_SIZE == swap_data)
330 swap_start = start_mem - PAGE_SIZE;
331
332 if (!swap_init( start_mem, swap_data )) {
333 printk( KERN_ERR "ST-RAM swap space initialization failed\n" );
334 max_swap_size = 0;
335 return;
336 }
337 /* reserve region for swapping meta-data */
338 reserve_region(swap_data, start_mem);
339 /* reserve swapping area itself */
340 reserve_region(swap_start + PAGE_SIZE, swap_end);
341
342 /*
343 * If the whole ST-RAM is used for swapping, there are no allocatable
344 * dma pages left. But unfortunately, some shared parts of the kernel
345 * (particularly the SCSI mid-level) call __get_dma_pages()
346 * unconditionally :-( These calls then fail, and scsi.c even doesn't
347 * check for NULL return values and just crashes. The quick fix for
348 * this (instead of doing much clean up work in the SCSI code) is to
349 * pretend all pages are DMA-able by setting mach_max_dma_address to
350 * ULONG_MAX. This doesn't change any functionality so far, since
351 * get_dma_pages() shouldn't be used on Atari anyway anymore (better
352 * use atari_stram_alloc()), and the Atari SCSI drivers don't need DMA
353 * memory. But unfortunately there's now no kind of warning (even not
354 * a NULL return value) if you use get_dma_pages() nevertheless :-(
355 * You just will get non-DMA-able memory...
356 */
357 mach_max_dma_address = 0xffffffff;
358 }
359#endif
360} 159}
361 160
362void atari_stram_mem_init_hook (void) 161void atari_stram_mem_init_hook (void)
@@ -367,7 +166,6 @@ void atari_stram_mem_init_hook (void)
367 166
368/* 167/*
369 * This is main public interface: somehow allocate a ST-RAM block 168 * This is main public interface: somehow allocate a ST-RAM block
370 * There are three strategies:
371 * 169 *
372 * - If we're before mem_init(), we have to make a static allocation. The 170 * - If we're before mem_init(), we have to make a static allocation. The
373 * region is taken in the kernel data area (if the kernel is in ST-RAM) or 171 * 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)
375 * rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel 173 * rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel
376 * address space in the latter case. 174 * address space in the latter case.
377 * 175 *
378 * - If mem_init() already has been called and ST-RAM swapping is enabled, 176 * - If mem_init() already has been called, try with __get_dma_pages().
379 * try to get the memory from the (pseudo) swap-space, either free already 177 * This has the disadvantage that it's very hard to get more than 1 page,
380 * or by moving some other pages out of the swap. 178 * and it is likely to fail :-(
381 *
382 * - If mem_init() already has been called, and ST-RAM swapping is not
383 * enabled, the only possibility is to try with __get_dma_pages(). This has
384 * the disadvantage that it's very hard to get more than 1 page, and it is
385 * likely to fail :-(
386 * 179 *
387 */ 180 */
388void *atari_stram_alloc(long size, const char *owner) 181void *atari_stram_alloc(long size, const char *owner)
@@ -393,27 +186,13 @@ void *atari_stram_alloc(long size, const char *owner)
393 186
394 DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner); 187 DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner);
395 188
396 size = ALIGN_IF_SWAP(size);
397 DPRINTK( "atari_stram_alloc: rounded size = %08lx\n", size );
398#ifdef CONFIG_STRAM_SWAP
399 if (max_swap_size) {
400 /* If swapping is active: make some free space in the swap
401 "device". */
402 DPRINTK( "atari_stram_alloc: after mem_init, swapping ok, "
403 "calling get_region\n" );
404 addr = get_stram_region( N_PAGES(size) );
405 flags = BLOCK_INSWAP;
406 }
407 else
408#endif
409 if (!mem_init_done) 189 if (!mem_init_done)
410 return alloc_bootmem_low(size); 190 return alloc_bootmem_low(size);
411 else { 191 else {
412 /* After mem_init() and no swapping: can only resort to 192 /* After mem_init(): can only resort to __get_dma_pages() */
413 * __get_dma_pages() */
414 addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size)); 193 addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size));
415 flags = BLOCK_GFP; 194 flags = BLOCK_GFP;
416 DPRINTK( "atari_stram_alloc: after mem_init, swapping off, " 195 DPRINTK( "atari_stram_alloc: after mem_init, "
417 "get_pages=%p\n", addr ); 196 "get_pages=%p\n", addr );
418 } 197 }
419 198
@@ -422,12 +201,7 @@ void *atari_stram_alloc(long size, const char *owner)
422 /* out of memory for BLOCK structure :-( */ 201 /* out of memory for BLOCK structure :-( */
423 DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- " 202 DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- "
424 "freeing again\n" ); 203 "freeing again\n" );
425#ifdef CONFIG_STRAM_SWAP 204 free_pages((unsigned long)addr, get_order(size));
426 if (flags == BLOCK_INSWAP)
427 free_stram_region( SWAP_NR(addr), N_PAGES(size) );
428 else
429#endif
430 free_pages((unsigned long)addr, get_order(size));
431 return( NULL ); 205 return( NULL );
432 } 206 }
433 block->owner = owner; 207 block->owner = owner;
@@ -451,25 +225,12 @@ void atari_stram_free( void *addr )
451 DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, " 225 DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, "
452 "flags=%02x\n", block, block->size, block->owner, block->flags ); 226 "flags=%02x\n", block, block->size, block->owner, block->flags );
453 227
454#ifdef CONFIG_STRAM_SWAP 228 if (!(block->flags & BLOCK_GFP))
455 if (!max_swap_size) {
456#endif
457 if (block->flags & BLOCK_GFP) {
458 DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n",
459 get_order(block->size));
460 free_pages((unsigned long)addr, get_order(block->size));
461 }
462 else
463 goto fail;
464#ifdef CONFIG_STRAM_SWAP
465 }
466 else if (block->flags & BLOCK_INSWAP) {
467 DPRINTK( "atari_stram_free: is swap-alloced\n" );
468 free_stram_region( SWAP_NR(block->start), N_PAGES(block->size) );
469 }
470 else
471 goto fail; 229 goto fail;
472#endif 230
231 DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n",
232 get_order(block->size));
233 free_pages((unsigned long)addr, get_order(block->size));
473 remove_region( block ); 234 remove_region( block );
474 return; 235 return;
475 236
@@ -478,612 +239,6 @@ void atari_stram_free( void *addr )
478 "(called from %p)\n", addr, __builtin_return_address(0) ); 239 "(called from %p)\n", addr, __builtin_return_address(0) );
479} 240}
480 241
481
482#ifdef CONFIG_STRAM_SWAP
483
484
485/* ------------------------------------------------------------------------ */
486/* Main Swapping Functions */
487/* ------------------------------------------------------------------------ */
488
489
490/*
491 * Initialize ST-RAM swap device
492 * (lots copied and modified from sys_swapon() in mm/swapfile.c)
493 */
494static int __init swap_init(void *start_mem, void *swap_data)
495{
496 static struct dentry fake_dentry;
497 static struct vfsmount fake_vfsmnt;
498 struct swap_info_struct *p;
499 struct inode swap_inode;
500 unsigned int type;
501 void *addr;
502 int i, j, k, prev;
503
504 DPRINTK("swap_init(start_mem=%p, swap_data=%p)\n",
505 start_mem, swap_data);
506
507 /* need at least one page for swapping to (and this also isn't very
508 * much... :-) */
509 if (swap_end - swap_start < 2*PAGE_SIZE) {
510 printk( KERN_WARNING "stram_swap_init: swap space too small\n" );
511 return( 0 );
512 }
513
514 /* find free slot in swap_info */
515 for( p = swap_info, type = 0; type < nr_swapfiles; type++, p++ )
516 if (!(p->flags & SWP_USED))
517 break;
518 if (type >= MAX_SWAPFILES) {
519 printk( KERN_WARNING "stram_swap_init: max. number of "
520 "swap devices exhausted\n" );
521 return( 0 );
522 }
523 if (type >= nr_swapfiles)
524 nr_swapfiles = type+1;
525
526 stram_swap_info = p;
527 stram_swap_type = type;
528
529 /* fake some dir cache entries to give us some name in /dev/swaps */
530 fake_dentry.d_parent = &fake_dentry;
531 fake_dentry.d_name.name = "stram (internal)";
532 fake_dentry.d_name.len = 16;
533 fake_vfsmnt.mnt_parent = &fake_vfsmnt;
534
535 p->flags = SWP_USED;
536 p->swap_file = &fake_dentry;
537 p->swap_vfsmnt = &fake_vfsmnt;
538 p->swap_map = swap_data;
539 p->cluster_nr = 0;
540 p->next = -1;
541 p->prio = 0x7ff0; /* a rather high priority, but not the higest
542 * to give the user a chance to override */
543
544 /* call stram_open() directly, avoids at least the overhead in
545 * constructing a dummy file structure... */
546 swap_inode.i_rdev = MKDEV( STRAM_MAJOR, STRAM_MINOR );
547 stram_open( &swap_inode, MAGIC_FILE_P );
548 p->max = SWAP_NR(swap_end);
549
550 /* initialize swap_map: set regions that are already allocated or belong
551 * to kernel data space to SWAP_MAP_BAD, otherwise to free */
552 j = 0; /* # of free pages */
553 k = 0; /* # of already allocated pages (from pre-mem_init stram_alloc()) */
554 p->lowest_bit = 0;
555 p->highest_bit = 0;
556 for( i = 1, addr = SWAP_ADDR(1); i < p->max;
557 i++, addr += PAGE_SIZE ) {
558 if (in_some_region( addr )) {
559 p->swap_map[i] = SWAP_MAP_BAD;
560 ++k;
561 }
562 else if (kernel_in_stram && addr < start_mem ) {
563 p->swap_map[i] = SWAP_MAP_BAD;
564 }
565 else {
566 p->swap_map[i] = 0;
567 ++j;
568 if (!p->lowest_bit) p->lowest_bit = i;
569 p->highest_bit = i;
570 }
571 }
572 /* first page always reserved (and doesn't really belong to swap space) */
573 p->swap_map[0] = SWAP_MAP_BAD;
574
575 /* now swapping to this device ok */
576 p->pages = j + k;
577 swap_list_lock();
578 nr_swap_pages += j;
579 p->flags = SWP_WRITEOK;
580
581 /* insert swap space into swap_list */
582 prev = -1;
583 for (i = swap_list.head; i >= 0; i = swap_info[i].next) {
584 if (p->prio >= swap_info[i].prio) {
585 break;
586 }
587 prev = i;
588 }
589 p->next = i;
590 if (prev < 0) {
591 swap_list.head = swap_list.next = p - swap_info;
592 } else {
593 swap_info[prev].next = p - swap_info;
594 }
595 swap_list_unlock();
596
597 printk( KERN_INFO "Using %dk (%d pages) of ST-RAM as swap space.\n",
598 p->pages << 2, p->pages );
599 return( 1 );
600}
601
602
603/*
604 * The swap entry has been read in advance, and we return 1 to indicate
605 * that the page has been used or is no longer needed.
606 *
607 * Always set the resulting pte to be nowrite (the same as COW pages
608 * after one process has exited). We don't know just how many PTEs will
609 * share this swap entry, so be cautious and let do_wp_page work out
610 * what to do if a write is requested later.
611 */
612static inline void unswap_pte(struct vm_area_struct * vma, unsigned long
613 address, pte_t *dir, swp_entry_t entry,
614 struct page *page)
615{
616 pte_t pte = *dir;
617
618 if (pte_none(pte))
619 return;
620 if (pte_present(pte)) {
621 /* If this entry is swap-cached, then page must already
622 hold the right address for any copies in physical
623 memory */
624 if (pte_page(pte) != page)
625 return;
626 /* We will be removing the swap cache in a moment, so... */
627 set_pte(dir, pte_mkdirty(pte));
628 return;
629 }
630 if (pte_val(pte) != entry.val)
631 return;
632
633 DPRINTK("unswap_pte: replacing entry %08lx by new page %p",
634 entry.val, page);
635 set_pte(dir, pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
636 swap_free(entry);
637 get_page(page);
638 inc_mm_counter(vma->vm_mm, rss);
639}
640
641static inline void unswap_pmd(struct vm_area_struct * vma, pmd_t *dir,
642 unsigned long address, unsigned long size,
643 unsigned long offset, swp_entry_t entry,
644 struct page *page)
645{
646 pte_t * pte;
647 unsigned long end;
648
649 if (pmd_none(*dir))
650 return;
651 if (pmd_bad(*dir)) {
652 pmd_ERROR(*dir);
653 pmd_clear(dir);
654 return;
655 }
656 pte = pte_offset_kernel(dir, address);
657 offset += address & PMD_MASK;
658 address &= ~PMD_MASK;
659 end = address + size;
660 if (end > PMD_SIZE)
661 end = PMD_SIZE;
662 do {
663 unswap_pte(vma, offset+address-vma->vm_start, pte, entry, page);
664 address += PAGE_SIZE;
665 pte++;
666 } while (address < end);
667}
668
669static inline void unswap_pgd(struct vm_area_struct * vma, pgd_t *dir,
670 unsigned long address, unsigned long size,
671 swp_entry_t entry, struct page *page)
672{
673 pmd_t * pmd;
674 unsigned long offset, end;
675
676 if (pgd_none(*dir))
677 return;
678 if (pgd_bad(*dir)) {
679 pgd_ERROR(*dir);
680 pgd_clear(dir);
681 return;
682 }
683 pmd = pmd_offset(dir, address);
684 offset = address & PGDIR_MASK;
685 address &= ~PGDIR_MASK;
686 end = address + size;
687 if (end > PGDIR_SIZE)
688 end = PGDIR_SIZE;
689 do {
690 unswap_pmd(vma, pmd, address, end - address, offset, entry,
691 page);
692 address = (address + PMD_SIZE) & PMD_MASK;
693 pmd++;
694 } while (address < end);
695}
696
697static void unswap_vma(struct vm_area_struct * vma, pgd_t *pgdir,
698 swp_entry_t entry, struct page *page)
699{
700 unsigned long start = vma->vm_start, end = vma->vm_end;
701
702 do {
703 unswap_pgd(vma, pgdir, start, end - start, entry, page);
704 start = (start + PGDIR_SIZE) & PGDIR_MASK;
705 pgdir++;
706 } while (start < end);
707}
708
709static void unswap_process(struct mm_struct * mm, swp_entry_t entry,
710 struct page *page)
711{
712 struct vm_area_struct* vma;
713
714 /*
715 * Go through process' page directory.
716 */
717 if (!mm)
718 return;
719 for (vma = mm->mmap; vma; vma = vma->vm_next) {
720 pgd_t * pgd = pgd_offset(mm, vma->vm_start);
721 unswap_vma(vma, pgd, entry, page);
722 }
723}
724
725
726static int unswap_by_read(unsigned short *map, unsigned long max,
727 unsigned long start, unsigned long n_pages)
728{
729 struct task_struct *p;
730 struct page *page;
731 swp_entry_t entry;
732 unsigned long i;
733
734 DPRINTK( "unswapping %lu..%lu by reading in\n",
735 start, start+n_pages-1 );
736
737 for( i = start; i < start+n_pages; ++i ) {
738 if (map[i] == SWAP_MAP_BAD) {
739 printk( KERN_ERR "get_stram_region: page %lu already "
740 "reserved??\n", i );
741 continue;
742 }
743
744 if (map[i]) {
745 entry = swp_entry(stram_swap_type, i);
746 DPRINTK("unswap: map[i=%lu]=%u nr_swap=%ld\n",
747 i, map[i], nr_swap_pages);
748
749 swap_device_lock(stram_swap_info);
750 map[i]++;
751 swap_device_unlock(stram_swap_info);
752 /* Get a page for the entry, using the existing
753 swap cache page if there is one. Otherwise,
754 get a clean page and read the swap into it. */
755 page = read_swap_cache_async(entry, NULL, 0);
756 if (!page) {
757 swap_free(entry);
758 return -ENOMEM;
759 }
760 read_lock(&tasklist_lock);
761 for_each_process(p)
762 unswap_process(p->mm, entry, page);
763 read_unlock(&tasklist_lock);
764 shmem_unuse(entry, page);
765 /* Now get rid of the extra reference to the
766 temporary page we've been using. */
767 if (PageSwapCache(page))
768 delete_from_swap_cache(page);
769 __free_page(page);
770 #ifdef DO_PROC
771 stat_swap_force++;
772 #endif
773 }
774
775 DPRINTK( "unswap: map[i=%lu]=%u nr_swap=%ld\n",
776 i, map[i], nr_swap_pages );
777 swap_list_lock();
778 swap_device_lock(stram_swap_info);
779 map[i] = SWAP_MAP_BAD;
780 if (stram_swap_info->lowest_bit == i)
781 stram_swap_info->lowest_bit++;
782 if (stram_swap_info->highest_bit == i)
783 stram_swap_info->highest_bit--;
784 --nr_swap_pages;
785 swap_device_unlock(stram_swap_info);
786 swap_list_unlock();
787 }
788
789 return 0;
790}
791
792/*
793 * reserve a region in ST-RAM swap space for an allocation
794 */
795static void *get_stram_region( unsigned long n_pages )
796{
797 unsigned short *map = stram_swap_info->swap_map;
798 unsigned long max = stram_swap_info->max;
799 unsigned long start, total_free, region_free;
800 int err;
801 void *ret = NULL;
802
803 DPRINTK( "get_stram_region(n_pages=%lu)\n", n_pages );
804
805 down(&stram_swap_sem);
806
807 /* disallow writing to the swap device now */
808 stram_swap_info->flags = SWP_USED;
809
810 /* find a region of n_pages pages in the swap space including as much free
811 * pages as possible (and excluding any already-reserved pages). */
812 if (!(start = find_free_region( n_pages, &total_free, &region_free )))
813 goto end;
814 DPRINTK( "get_stram_region: region starts at %lu, has %lu free pages\n",
815 start, region_free );
816
817 err = unswap_by_read(map, max, start, n_pages);
818 if (err)
819 goto end;
820
821 ret = SWAP_ADDR(start);
822 end:
823 /* allow using swap device again */
824 stram_swap_info->flags = SWP_WRITEOK;
825 up(&stram_swap_sem);
826 DPRINTK( "get_stram_region: returning %p\n", ret );
827 return( ret );
828}
829
830
831/*
832 * free a reserved region in ST-RAM swap space
833 */
834static void free_stram_region( unsigned long offset, unsigned long n_pages )
835{
836 unsigned short *map = stram_swap_info->swap_map;
837
838 DPRINTK( "free_stram_region(offset=%lu,n_pages=%lu)\n", offset, n_pages );
839
840 if (offset < 1 || offset + n_pages > stram_swap_info->max) {
841 printk( KERN_ERR "free_stram_region: Trying to free non-ST-RAM\n" );
842 return;
843 }
844
845 swap_list_lock();
846 swap_device_lock(stram_swap_info);
847 /* un-reserve the freed pages */
848 for( ; n_pages > 0; ++offset, --n_pages ) {
849 if (map[offset] != SWAP_MAP_BAD)
850 printk( KERN_ERR "free_stram_region: Swap page %lu was not "
851 "reserved\n", offset );
852 map[offset] = 0;
853 }
854
855 /* update swapping meta-data */
856 if (offset < stram_swap_info->lowest_bit)
857 stram_swap_info->lowest_bit = offset;
858 if (offset+n_pages-1 > stram_swap_info->highest_bit)
859 stram_swap_info->highest_bit = offset+n_pages-1;
860 if (stram_swap_info->prio > swap_info[swap_list.next].prio)
861 swap_list.next = swap_list.head;
862 nr_swap_pages += n_pages;
863 swap_device_unlock(stram_swap_info);
864 swap_list_unlock();
865}
866
867
868/* ------------------------------------------------------------------------ */
869/* Utility Functions for Swapping */
870/* ------------------------------------------------------------------------ */
871
872
873/* is addr in some of the allocated regions? */
874static int in_some_region(void *addr)
875{
876 BLOCK *p;
877
878 for( p = alloc_list; p; p = p->next ) {
879 if (p->start <= addr && addr < p->start + p->size)
880 return( 1 );
881 }
882 return( 0 );
883}
884
885
886static unsigned long find_free_region(unsigned long n_pages,
887 unsigned long *total_free,
888 unsigned long *region_free)
889{
890 unsigned short *map = stram_swap_info->swap_map;
891 unsigned long max = stram_swap_info->max;
892 unsigned long head, tail, max_start;
893 long nfree, max_free;
894
895 /* first scan the swap space for a suitable place for the allocation */
896 head = 1;
897 max_start = 0;
898 max_free = -1;
899 *total_free = 0;
900
901 start_over:
902 /* increment tail until final window size reached, and count free pages */
903 nfree = 0;
904 for( tail = head; tail-head < n_pages && tail < max; ++tail ) {
905 if (map[tail] == SWAP_MAP_BAD) {
906 head = tail+1;
907 goto start_over;
908 }
909 if (!map[tail]) {
910 ++nfree;
911 ++*total_free;
912 }
913 }
914 if (tail-head < n_pages)
915 goto out;
916 if (nfree > max_free) {
917 max_start = head;
918 max_free = nfree;
919 if (max_free >= n_pages)
920 /* don't need more free pages... :-) */
921 goto out;
922 }
923
924 /* now shift the window and look for the area where as much pages as
925 * possible are free */
926 while( tail < max ) {
927 nfree -= (map[head++] == 0);
928 if (map[tail] == SWAP_MAP_BAD) {
929 head = tail+1;
930 goto start_over;
931 }
932 if (!map[tail]) {
933 ++nfree;
934 ++*total_free;
935 }
936 ++tail;
937 if (nfree > max_free) {
938 max_start = head;
939 max_free = nfree;
940 if (max_free >= n_pages)
941 /* don't need more free pages... :-) */
942 goto out;
943 }
944 }
945
946 out:
947 if (max_free < 0) {
948 printk( KERN_NOTICE "get_stram_region: ST-RAM too full or fragmented "
949 "-- can't allocate %lu pages\n", n_pages );
950 return( 0 );
951 }
952
953 *region_free = max_free;
954 return( max_start );
955}
956
957
958/* setup parameters from command line */
959void __init stram_swap_setup(char *str, int *ints)
960{
961 if (ints[0] >= 1)
962 max_swap_size = ((ints[1] < 0 ? 0 : ints[1]) * 1024) & PAGE_MASK;
963}
964
965
966/* ------------------------------------------------------------------------ */
967/* ST-RAM device */
968/* ------------------------------------------------------------------------ */
969
970static int refcnt;
971
972static void do_stram_request(request_queue_t *q)
973{
974 struct request *req;
975
976 while ((req = elv_next_request(q)) != NULL) {
977 void *start = swap_start + (req->sector << 9);
978 unsigned long len = req->current_nr_sectors << 9;
979 if ((start + len) > swap_end) {
980 printk( KERN_ERR "stram: bad access beyond end of device: "
981 "block=%ld, count=%d\n",
982 req->sector,
983 req->current_nr_sectors );
984 end_request(req, 0);
985 continue;
986 }
987
988 if (req->cmd == READ) {
989 memcpy(req->buffer, start, len);
990#ifdef DO_PROC
991 stat_swap_read += N_PAGES(len);
992#endif
993 }
994 else {
995 memcpy(start, req->buffer, len);
996#ifdef DO_PROC
997 stat_swap_write += N_PAGES(len);
998#endif
999 }
1000 end_request(req, 1);
1001 }
1002}
1003
1004
1005static int stram_open( struct inode *inode, struct file *filp )
1006{
1007 if (filp != MAGIC_FILE_P) {
1008 printk( KERN_NOTICE "Only kernel can open ST-RAM device\n" );
1009 return( -EPERM );
1010 }
1011 if (refcnt)
1012 return( -EBUSY );
1013 ++refcnt;
1014 return( 0 );
1015}
1016
1017static int stram_release( struct inode *inode, struct file *filp )
1018{
1019 if (filp != MAGIC_FILE_P) {
1020 printk( KERN_NOTICE "Only kernel can close ST-RAM device\n" );
1021 return( -EPERM );
1022 }
1023 if (refcnt > 0)
1024 --refcnt;
1025 return( 0 );
1026}
1027
1028
1029static struct block_device_operations stram_fops = {
1030 .open = stram_open,
1031 .release = stram_release,
1032};
1033
1034static struct gendisk *stram_disk;
1035static struct request_queue *stram_queue;
1036static DEFINE_SPINLOCK(stram_lock);
1037
1038int __init stram_device_init(void)
1039{
1040 if (!MACH_IS_ATARI)
1041 /* no point in initializing this, I hope */
1042 return -ENXIO;
1043
1044 if (!max_swap_size)
1045 /* swapping not enabled */
1046 return -ENXIO;
1047 stram_disk = alloc_disk(1);
1048 if (!stram_disk)
1049 return -ENOMEM;
1050
1051 if (register_blkdev(STRAM_MAJOR, "stram")) {
1052 put_disk(stram_disk);
1053 return -ENXIO;
1054 }
1055
1056 stram_queue = blk_init_queue(do_stram_request, &stram_lock);
1057 if (!stram_queue) {
1058 unregister_blkdev(STRAM_MAJOR, "stram");
1059 put_disk(stram_disk);
1060 return -ENOMEM;
1061 }
1062
1063 stram_disk->major = STRAM_MAJOR;
1064 stram_disk->first_minor = STRAM_MINOR;
1065 stram_disk->fops = &stram_fops;
1066 stram_disk->queue = stram_queue;
1067 sprintf(stram_disk->disk_name, "stram");
1068 set_capacity(stram_disk, (swap_end - swap_start)/512);
1069 add_disk(stram_disk);
1070 return 0;
1071}
1072
1073
1074
1075/* ------------------------------------------------------------------------ */
1076/* Misc Utility Functions */
1077/* ------------------------------------------------------------------------ */
1078
1079/* reserve a range of pages */
1080static void reserve_region(void *start, void *end)
1081{
1082 reserve_bootmem (virt_to_phys(start), end - start);
1083}
1084
1085#endif /* CONFIG_STRAM_SWAP */
1086
1087 242
1088/* ------------------------------------------------------------------------ */ 243/* ------------------------------------------------------------------------ */
1089/* Region Management */ 244/* Region Management */
@@ -1173,50 +328,9 @@ int get_stram_list( char *buf )
1173{ 328{
1174 int len = 0; 329 int len = 0;
1175 BLOCK *p; 330 BLOCK *p;
1176#ifdef CONFIG_STRAM_SWAP
1177 int i;
1178 unsigned short *map = stram_swap_info->swap_map;
1179 unsigned long max = stram_swap_info->max;
1180 unsigned free = 0, used = 0, rsvd = 0;
1181#endif
1182 331
1183#ifdef CONFIG_STRAM_SWAP 332 PRINT_PROC("Total ST-RAM: %8u kB\n",
1184 if (max_swap_size) {
1185 for( i = 1; i < max; ++i ) {
1186 if (!map[i])
1187 ++free;
1188 else if (map[i] == SWAP_MAP_BAD)
1189 ++rsvd;
1190 else
1191 ++used;
1192 }
1193 PRINT_PROC(
1194 "Total ST-RAM: %8u kB\n"
1195 "Total ST-RAM swap: %8lu kB\n"
1196 "Free swap: %8u kB\n"
1197 "Used swap: %8u kB\n"
1198 "Allocated swap: %8u kB\n"
1199 "Swap Reads: %8u\n"
1200 "Swap Writes: %8u\n"
1201 "Swap Forced Reads: %8u\n",
1202 (stram_end - stram_start) >> 10,
1203 (max-1) << (PAGE_SHIFT-10),
1204 free << (PAGE_SHIFT-10),
1205 used << (PAGE_SHIFT-10),
1206 rsvd << (PAGE_SHIFT-10),
1207 stat_swap_read,
1208 stat_swap_write,
1209 stat_swap_force );
1210 }
1211 else {
1212#endif
1213 PRINT_PROC( "ST-RAM swapping disabled\n" );
1214 PRINT_PROC("Total ST-RAM: %8u kB\n",
1215 (stram_end - stram_start) >> 10); 333 (stram_end - stram_start) >> 10);
1216#ifdef CONFIG_STRAM_SWAP
1217 }
1218#endif
1219
1220 PRINT_PROC( "Allocated regions:\n" ); 334 PRINT_PROC( "Allocated regions:\n" );
1221 for( p = alloc_list; p; p = p->next ) { 335 for( p = alloc_list; p; p = p->next ) {
1222 if (len + 50 >= PAGE_SIZE) 336 if (len + 50 >= PAGE_SIZE)
@@ -1227,8 +341,6 @@ int get_stram_list( char *buf )
1227 p->owner); 341 p->owner);
1228 if (p->flags & BLOCK_GFP) 342 if (p->flags & BLOCK_GFP)
1229 PRINT_PROC( "page-alloced)\n" ); 343 PRINT_PROC( "page-alloced)\n" );
1230 else if (p->flags & BLOCK_INSWAP)
1231 PRINT_PROC( "in swap)\n" );
1232 else 344 else
1233 PRINT_PROC( "??)\n" ); 345 PRINT_PROC( "??)\n" );
1234 } 346 }
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-01 14:43:13 -0500