1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19#include <linux/mm.h>
20#include <linux/module.h>
21#include <linux/swap.h>
22#include <linux/bio.h>
23#include <linux/pagemap.h>
24#include <linux/mempool.h>
25#include <linux/blkdev.h>
26#include <linux/init.h>
27#include <linux/hash.h>
28#include <linux/highmem.h>
29#include <asm/tlbflush.h>
30
31
32
33
34
35
36
37
38
39#ifdef CONFIG_HIGHMEM
40
41unsigned long totalhigh_pages __read_mostly;
42EXPORT_SYMBOL(totalhigh_pages);
43
44unsigned int nr_free_highpages (void)
45{
46 pg_data_t *pgdat;
47 unsigned int pages = 0;
48
49 for_each_online_pgdat(pgdat) {
50 pages += zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
51 NR_FREE_PAGES);
52 if (zone_movable_is_highmem())
53 pages += zone_page_state(
54 &pgdat->node_zones[ZONE_MOVABLE],
55 NR_FREE_PAGES);
56 }
57
58 return pages;
59}
60
61static int pkmap_count[LAST_PKMAP];
62static unsigned int last_pkmap_nr;
63static __cacheline_aligned_in_smp DEFINE_SPINLOCK(kmap_lock);
64
65pte_t * pkmap_page_table;
66
67static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait);
68
69
70
71
72
73
74#ifdef ARCH_NEEDS_KMAP_HIGH_GET
75#define lock_kmap() spin_lock_irq(&kmap_lock)
76#define unlock_kmap() spin_unlock_irq(&kmap_lock)
77#define lock_kmap_any(flags) spin_lock_irqsave(&kmap_lock, flags)
78#define unlock_kmap_any(flags) spin_unlock_irqrestore(&kmap_lock, flags)
79#else
80#define lock_kmap() spin_lock(&kmap_lock)
81#define unlock_kmap() spin_unlock(&kmap_lock)
82#define lock_kmap_any(flags) \
83 do { spin_lock(&kmap_lock); (void)(flags); } while (0)
84#define unlock_kmap_any(flags) \
85 do { spin_unlock(&kmap_lock); (void)(flags); } while (0)
86#endif
87
88static void flush_all_zero_pkmaps(void)
89{
90 int i;
91 int need_flush = 0;
92
93 flush_cache_kmaps();
94
95 for (i = 0; i < LAST_PKMAP; i++) {
96 struct page *page;
97
98
99
100
101
102
103
104 if (pkmap_count[i] != 1)
105 continue;
106 pkmap_count[i] = 0;
107
108
109 BUG_ON(pte_none(pkmap_page_table[i]));
110
111
112
113
114
115
116
117
118 page = pte_page(pkmap_page_table[i]);
119 pte_clear(&init_mm, (unsigned long)page_address(page),
120 &pkmap_page_table[i]);
121
122 set_page_address(page, NULL);
123 need_flush = 1;
124 }
125 if (need_flush)
126 flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
127}
128
129
130
131
132void kmap_flush_unused(void)
133{
134 lock_kmap();
135 flush_all_zero_pkmaps();
136 unlock_kmap();
137}
138
139static inline unsigned long map_new_virtual(struct page *page)
140{
141 unsigned long vaddr;
142 int count;
143
144start:
145 count = LAST_PKMAP;
146
147 for (;;) {
148 last_pkmap_nr = (last_pkmap_nr + 1) & LAST_PKMAP_MASK;
149 if (!last_pkmap_nr) {
150 flush_all_zero_pkmaps();
151 count = LAST_PKMAP;
152 }
153 if (!pkmap_count[last_pkmap_nr])
154 break;
155 if (--count)
156 continue;
157
158
159
160
161 {
162 DECLARE_WAITQUEUE(wait, current);
163
164 __set_current_state(TASK_UNINTERRUPTIBLE);
165 add_wait_queue(&pkmap_map_wait, &wait);
166 unlock_kmap();
167 schedule();
168 remove_wait_queue(&pkmap_map_wait, &wait);
169 lock_kmap();
170
171
172 if (page_address(page))
173 return (unsigned long)page_address(page);
174
175
176 goto start;
177 }
178 }
179 vaddr = PKMAP_ADDR(last_pkmap_nr);
180 set_pte_at(&init_mm, vaddr,
181 &(pkmap_page_table[last_pkmap_nr]), mk_pte(page, kmap_prot));
182
183 pkmap_count[last_pkmap_nr] = 1;
184 set_page_address(page, (void *)vaddr);
185
186 return vaddr;
187}
188
189
190
191
192
193
194
195
196
197void *kmap_high(struct page *page)
198{
199 unsigned long vaddr;
200
201
202
203
204
205 lock_kmap();
206 vaddr = (unsigned long)page_address(page);
207 if (!vaddr)
208 vaddr = map_new_virtual(page);
209 pkmap_count[PKMAP_NR(vaddr)]++;
210 BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 2);
211 unlock_kmap();
212 return (void*) vaddr;
213}
214
215EXPORT_SYMBOL(kmap_high);
216
217#ifdef ARCH_NEEDS_KMAP_HIGH_GET
218
219
220
221
222
223
224
225
226
227
228void *kmap_high_get(struct page *page)
229{
230 unsigned long vaddr, flags;
231
232 lock_kmap_any(flags);
233 vaddr = (unsigned long)page_address(page);
234 if (vaddr) {
235 BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 1);
236 pkmap_count[PKMAP_NR(vaddr)]++;
237 }
238 unlock_kmap_any(flags);
239 return (void*) vaddr;
240}
241#endif
242
243
244
245
246
247
248
249
250void kunmap_high(struct page *page)
251{
252 unsigned long vaddr;
253 unsigned long nr;
254 unsigned long flags;
255 int need_wakeup;
256
257 lock_kmap_any(flags);
258 vaddr = (unsigned long)page_address(page);
259 BUG_ON(!vaddr);
260 nr = PKMAP_NR(vaddr);
261
262
263
264
265
266 need_wakeup = 0;
267 switch (--pkmap_count[nr]) {
268 case 0:
269 BUG();
270 case 1:
271
272
273
274
275
276
277
278
279
280
281 need_wakeup = waitqueue_active(&pkmap_map_wait);
282 }
283 unlock_kmap_any(flags);
284
285
286 if (need_wakeup)
287 wake_up(&pkmap_map_wait);
288}
289
290EXPORT_SYMBOL(kunmap_high);
291#endif
292
293#if defined(HASHED_PAGE_VIRTUAL)
294
295#define PA_HASH_ORDER 7
296
297
298
299
300struct page_address_map {
301 struct page *page;
302 void *virtual;
303 struct list_head list;
304};
305
306
307
308
309static struct list_head page_address_pool;
310static spinlock_t pool_lock;
311
312
313
314
315static struct page_address_slot {
316 struct list_head lh;
317 spinlock_t lock;
318} ____cacheline_aligned_in_smp page_address_htable[1<<PA_HASH_ORDER];
319
320static struct page_address_slot *page_slot(struct page *page)
321{
322 return &page_address_htable[hash_ptr(page, PA_HASH_ORDER)];
323}
324
325
326
327
328
329
330
331void *page_address(struct page *page)
332{
333 unsigned long flags;
334 void *ret;
335 struct page_address_slot *pas;
336
337 if (!PageHighMem(page))
338 return lowmem_page_address(page);
339
340 pas = page_slot(page);
341 ret = NULL;
342 spin_lock_irqsave(&pas->lock, flags);
343 if (!list_empty(&pas->lh)) {
344 struct page_address_map *pam;
345
346 list_for_each_entry(pam, &pas->lh, list) {
347 if (pam->page == page) {
348 ret = pam->virtual;
349 goto done;
350 }
351 }
352 }
353done:
354 spin_unlock_irqrestore(&pas->lock, flags);
355 return ret;
356}
357
358EXPORT_SYMBOL(page_address);
359
360
361
362
363
364
365void set_page_address(struct page *page, void *virtual)
366{
367 unsigned long flags;
368 struct page_address_slot *pas;
369 struct page_address_map *pam;
370
371 BUG_ON(!PageHighMem(page));
372
373 pas = page_slot(page);
374 if (virtual) {
375 BUG_ON(list_empty(&page_address_pool));
376
377 spin_lock_irqsave(&pool_lock, flags);
378 pam = list_entry(page_address_pool.next,
379 struct page_address_map, list);
380 list_del(&pam->list);
381 spin_unlock_irqrestore(&pool_lock, flags);
382
383 pam->page = page;
384 pam->virtual = virtual;
385
386 spin_lock_irqsave(&pas->lock, flags);
387 list_add_tail(&pam->list, &pas->lh);
388 spin_unlock_irqrestore(&pas->lock, flags);
389 } else {
390 spin_lock_irqsave(&pas->lock, flags);
391 list_for_each_entry(pam, &pas->lh, list) {
392 if (pam->page == page) {
393 list_del(&pam->list);
394 spin_unlock_irqrestore(&pas->lock, flags);
395 spin_lock_irqsave(&pool_lock, flags);
396 list_add_tail(&pam->list, &page_address_pool);
397 spin_unlock_irqrestore(&pool_lock, flags);
398 goto done;
399 }
400 }
401 spin_unlock_irqrestore(&pas->lock, flags);
402 }
403done:
404 return;
405}
406
407static struct page_address_map page_address_maps[LAST_PKMAP];
408
409void __init page_address_init(void)
410{
411 int i;
412
413 INIT_LIST_HEAD(&page_address_pool);
414 for (i = 0; i < ARRAY_SIZE(page_address_maps); i++)
415 list_add(&page_address_maps[i].list, &page_address_pool);
416 for (i = 0; i < ARRAY_SIZE(page_address_htable); i++) {
417 INIT_LIST_HEAD(&page_address_htable[i].lh);
418 spin_lock_init(&page_address_htable[i].lock);
419 }
420 spin_lock_init(&pool_lock);
421}
422
423#endif
424
425#if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT)
426
427void debug_kmap_atomic(enum km_type type)
428{
429 static int warn_count = 10;
430
431 if (unlikely(warn_count < 0))
432 return;
433
434 if (unlikely(in_interrupt())) {
435 if (in_nmi()) {
436 if (type != KM_NMI && type != KM_NMI_PTE) {
437 WARN_ON(1);
438 warn_count--;
439 }
440 } else if (in_irq()) {
441 if (type != KM_IRQ0 && type != KM_IRQ1 &&
442 type != KM_BIO_SRC_IRQ && type != KM_BIO_DST_IRQ &&
443 type != KM_BOUNCE_READ && type != KM_IRQ_PTE) {
444 WARN_ON(1);
445 warn_count--;
446 }
447 } else if (!irqs_disabled()) {
448 if (type != KM_IRQ0 && type != KM_IRQ1 &&
449 type != KM_SOFTIRQ0 && type != KM_SOFTIRQ1 &&
450 type != KM_SKB_SUNRPC_DATA &&
451 type != KM_SKB_DATA_SOFTIRQ &&
452 type != KM_BOUNCE_READ) {
453 WARN_ON(1);
454 warn_count--;
455 }
456 }
457 }
458
459 if (type == KM_IRQ0 || type == KM_IRQ1 || type == KM_BOUNCE_READ ||
460 type == KM_BIO_SRC_IRQ || type == KM_BIO_DST_IRQ ||
461 type == KM_IRQ_PTE || type == KM_NMI ||
462 type == KM_NMI_PTE ) {
463 if (!irqs_disabled()) {
464 WARN_ON(1);
465 warn_count--;
466 }
467 } else if (type == KM_SOFTIRQ0 || type == KM_SOFTIRQ1) {
468 if (irq_count() == 0 && !irqs_disabled()) {
469 WARN_ON(1);
470 warn_count--;
471 }
472 }
473}
474
475#endif
476