Commit | Line | Data |
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831058de DH |
1 | /* bounce buffer handling for block devices |
2 | * | |
3 | * - Split from highmem.c | |
4 | */ | |
5 | ||
6 | #include <linux/mm.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/swap.h> | |
9 | #include <linux/bio.h> | |
10 | #include <linux/pagemap.h> | |
11 | #include <linux/mempool.h> | |
12 | #include <linux/blkdev.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/hash.h> | |
15 | #include <linux/highmem.h> | |
831058de DH |
16 | #include <asm/tlbflush.h> |
17 | ||
55782138 LZ |
18 | #include <trace/events/block.h> |
19 | ||
831058de DH |
20 | #define POOL_SIZE 64 |
21 | #define ISA_POOL_SIZE 16 | |
22 | ||
23 | static mempool_t *page_pool, *isa_page_pool; | |
24 | ||
25 | #ifdef CONFIG_HIGHMEM | |
26 | static __init int init_emergency_pool(void) | |
27 | { | |
28 | struct sysinfo i; | |
29 | si_meminfo(&i); | |
30 | si_swapinfo(&i); | |
31 | ||
32 | if (!i.totalhigh) | |
33 | return 0; | |
34 | ||
35 | page_pool = mempool_create_page_pool(POOL_SIZE, 0); | |
36 | BUG_ON(!page_pool); | |
37 | printk("highmem bounce pool size: %d pages\n", POOL_SIZE); | |
38 | ||
39 | return 0; | |
40 | } | |
41 | ||
42 | __initcall(init_emergency_pool); | |
43 | ||
44 | /* | |
45 | * highmem version, map in to vec | |
46 | */ | |
47 | static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) | |
48 | { | |
49 | unsigned long flags; | |
50 | unsigned char *vto; | |
51 | ||
52 | local_irq_save(flags); | |
53 | vto = kmap_atomic(to->bv_page, KM_BOUNCE_READ); | |
54 | memcpy(vto + to->bv_offset, vfrom, to->bv_len); | |
55 | kunmap_atomic(vto, KM_BOUNCE_READ); | |
56 | local_irq_restore(flags); | |
57 | } | |
58 | ||
59 | #else /* CONFIG_HIGHMEM */ | |
60 | ||
61 | #define bounce_copy_vec(to, vfrom) \ | |
62 | memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) | |
63 | ||
64 | #endif /* CONFIG_HIGHMEM */ | |
65 | ||
66 | /* | |
67 | * allocate pages in the DMA region for the ISA pool | |
68 | */ | |
69 | static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) | |
70 | { | |
71 | return mempool_alloc_pages(gfp_mask | GFP_DMA, data); | |
72 | } | |
73 | ||
74 | /* | |
75 | * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA | |
76 | * as the max address, so check if the pool has already been created. | |
77 | */ | |
78 | int init_emergency_isa_pool(void) | |
79 | { | |
80 | if (isa_page_pool) | |
81 | return 0; | |
82 | ||
83 | isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, | |
84 | mempool_free_pages, (void *) 0); | |
85 | BUG_ON(!isa_page_pool); | |
86 | ||
87 | printk("isa bounce pool size: %d pages\n", ISA_POOL_SIZE); | |
88 | return 0; | |
89 | } | |
90 | ||
91 | /* | |
92 | * Simple bounce buffer support for highmem pages. Depending on the | |
93 | * queue gfp mask set, *to may or may not be a highmem page. kmap it | |
94 | * always, it will do the Right Thing | |
95 | */ | |
96 | static void copy_to_high_bio_irq(struct bio *to, struct bio *from) | |
97 | { | |
98 | unsigned char *vfrom; | |
99 | struct bio_vec *tovec, *fromvec; | |
100 | int i; | |
101 | ||
102 | __bio_for_each_segment(tovec, to, i, 0) { | |
103 | fromvec = from->bi_io_vec + i; | |
104 | ||
105 | /* | |
106 | * not bounced | |
107 | */ | |
108 | if (tovec->bv_page == fromvec->bv_page) | |
109 | continue; | |
110 | ||
111 | /* | |
112 | * fromvec->bv_offset and fromvec->bv_len might have been | |
113 | * modified by the block layer, so use the original copy, | |
114 | * bounce_copy_vec already uses tovec->bv_len | |
115 | */ | |
116 | vfrom = page_address(fromvec->bv_page) + tovec->bv_offset; | |
117 | ||
118 | flush_dcache_page(tovec->bv_page); | |
119 | bounce_copy_vec(tovec, vfrom); | |
120 | } | |
121 | } | |
122 | ||
123 | static void bounce_end_io(struct bio *bio, mempool_t *pool, int err) | |
124 | { | |
125 | struct bio *bio_orig = bio->bi_private; | |
126 | struct bio_vec *bvec, *org_vec; | |
127 | int i; | |
128 | ||
129 | if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags)) | |
130 | set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags); | |
131 | ||
132 | /* | |
133 | * free up bounce indirect pages used | |
134 | */ | |
135 | __bio_for_each_segment(bvec, bio, i, 0) { | |
136 | org_vec = bio_orig->bi_io_vec + i; | |
137 | if (bvec->bv_page == org_vec->bv_page) | |
138 | continue; | |
139 | ||
140 | dec_zone_page_state(bvec->bv_page, NR_BOUNCE); | |
141 | mempool_free(bvec->bv_page, pool); | |
142 | } | |
143 | ||
6712ecf8 | 144 | bio_endio(bio_orig, err); |
831058de DH |
145 | bio_put(bio); |
146 | } | |
147 | ||
6712ecf8 | 148 | static void bounce_end_io_write(struct bio *bio, int err) |
831058de | 149 | { |
831058de | 150 | bounce_end_io(bio, page_pool, err); |
831058de DH |
151 | } |
152 | ||
6712ecf8 | 153 | static void bounce_end_io_write_isa(struct bio *bio, int err) |
831058de | 154 | { |
831058de DH |
155 | |
156 | bounce_end_io(bio, isa_page_pool, err); | |
831058de DH |
157 | } |
158 | ||
159 | static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err) | |
160 | { | |
161 | struct bio *bio_orig = bio->bi_private; | |
162 | ||
163 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
164 | copy_to_high_bio_irq(bio_orig, bio); | |
165 | ||
166 | bounce_end_io(bio, pool, err); | |
167 | } | |
168 | ||
6712ecf8 | 169 | static void bounce_end_io_read(struct bio *bio, int err) |
831058de | 170 | { |
831058de | 171 | __bounce_end_io_read(bio, page_pool, err); |
831058de DH |
172 | } |
173 | ||
6712ecf8 | 174 | static void bounce_end_io_read_isa(struct bio *bio, int err) |
831058de | 175 | { |
831058de | 176 | __bounce_end_io_read(bio, isa_page_pool, err); |
831058de DH |
177 | } |
178 | ||
165125e1 | 179 | static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, |
831058de DH |
180 | mempool_t *pool) |
181 | { | |
182 | struct page *page; | |
183 | struct bio *bio = NULL; | |
184 | int i, rw = bio_data_dir(*bio_orig); | |
185 | struct bio_vec *to, *from; | |
186 | ||
187 | bio_for_each_segment(from, *bio_orig, i) { | |
188 | page = from->bv_page; | |
189 | ||
190 | /* | |
191 | * is destination page below bounce pfn? | |
192 | */ | |
ae03bf63 | 193 | if (page_to_pfn(page) <= queue_bounce_pfn(q)) |
831058de DH |
194 | continue; |
195 | ||
196 | /* | |
197 | * irk, bounce it | |
198 | */ | |
f735b5ee JA |
199 | if (!bio) { |
200 | unsigned int cnt = (*bio_orig)->bi_vcnt; | |
201 | ||
202 | bio = bio_alloc(GFP_NOIO, cnt); | |
203 | memset(bio->bi_io_vec, 0, cnt * sizeof(struct bio_vec)); | |
204 | } | |
205 | ||
831058de DH |
206 | |
207 | to = bio->bi_io_vec + i; | |
208 | ||
209 | to->bv_page = mempool_alloc(pool, q->bounce_gfp); | |
210 | to->bv_len = from->bv_len; | |
211 | to->bv_offset = from->bv_offset; | |
212 | inc_zone_page_state(to->bv_page, NR_BOUNCE); | |
213 | ||
214 | if (rw == WRITE) { | |
215 | char *vto, *vfrom; | |
216 | ||
217 | flush_dcache_page(from->bv_page); | |
218 | vto = page_address(to->bv_page) + to->bv_offset; | |
219 | vfrom = kmap(from->bv_page) + from->bv_offset; | |
220 | memcpy(vto, vfrom, to->bv_len); | |
221 | kunmap(from->bv_page); | |
222 | } | |
223 | } | |
224 | ||
225 | /* | |
226 | * no pages bounced | |
227 | */ | |
228 | if (!bio) | |
229 | return; | |
230 | ||
5f3ea37c | 231 | trace_block_bio_bounce(q, *bio_orig); |
c43a5082 | 232 | |
831058de DH |
233 | /* |
234 | * at least one page was bounced, fill in possible non-highmem | |
235 | * pages | |
236 | */ | |
237 | __bio_for_each_segment(from, *bio_orig, i, 0) { | |
238 | to = bio_iovec_idx(bio, i); | |
239 | if (!to->bv_page) { | |
240 | to->bv_page = from->bv_page; | |
241 | to->bv_len = from->bv_len; | |
242 | to->bv_offset = from->bv_offset; | |
243 | } | |
244 | } | |
245 | ||
246 | bio->bi_bdev = (*bio_orig)->bi_bdev; | |
247 | bio->bi_flags |= (1 << BIO_BOUNCED); | |
248 | bio->bi_sector = (*bio_orig)->bi_sector; | |
249 | bio->bi_rw = (*bio_orig)->bi_rw; | |
250 | ||
251 | bio->bi_vcnt = (*bio_orig)->bi_vcnt; | |
252 | bio->bi_idx = (*bio_orig)->bi_idx; | |
253 | bio->bi_size = (*bio_orig)->bi_size; | |
254 | ||
255 | if (pool == page_pool) { | |
256 | bio->bi_end_io = bounce_end_io_write; | |
257 | if (rw == READ) | |
258 | bio->bi_end_io = bounce_end_io_read; | |
259 | } else { | |
260 | bio->bi_end_io = bounce_end_io_write_isa; | |
261 | if (rw == READ) | |
262 | bio->bi_end_io = bounce_end_io_read_isa; | |
263 | } | |
264 | ||
265 | bio->bi_private = *bio_orig; | |
266 | *bio_orig = bio; | |
267 | } | |
268 | ||
165125e1 | 269 | void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) |
831058de DH |
270 | { |
271 | mempool_t *pool; | |
272 | ||
bf2de6f5 JA |
273 | /* |
274 | * Data-less bio, nothing to bounce | |
275 | */ | |
36144077 | 276 | if (!bio_has_data(*bio_orig)) |
bf2de6f5 JA |
277 | return; |
278 | ||
831058de DH |
279 | /* |
280 | * for non-isa bounce case, just check if the bounce pfn is equal | |
281 | * to or bigger than the highest pfn in the system -- in that case, | |
282 | * don't waste time iterating over bio segments | |
283 | */ | |
284 | if (!(q->bounce_gfp & GFP_DMA)) { | |
ae03bf63 | 285 | if (queue_bounce_pfn(q) >= blk_max_pfn) |
831058de DH |
286 | return; |
287 | pool = page_pool; | |
288 | } else { | |
289 | BUG_ON(!isa_page_pool); | |
290 | pool = isa_page_pool; | |
291 | } | |
292 | ||
831058de DH |
293 | /* |
294 | * slow path | |
295 | */ | |
296 | __blk_queue_bounce(q, bio_orig, pool); | |
297 | } | |
298 | ||
299 | EXPORT_SYMBOL(blk_queue_bounce); |