Root/
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/gfp.h> |
10 | #include <linux/bio.h> |
11 | #include <linux/pagemap.h> |
12 | #include <linux/mempool.h> |
13 | #include <linux/blkdev.h> |
14 | #include <linux/init.h> |
15 | #include <linux/hash.h> |
16 | #include <linux/highmem.h> |
17 | #include <asm/tlbflush.h> |
18 | |
19 | #include <trace/events/block.h> |
20 | |
21 | #define POOL_SIZE 64 |
22 | #define ISA_POOL_SIZE 16 |
23 | |
24 | static mempool_t *page_pool, *isa_page_pool; |
25 | |
26 | #ifdef CONFIG_HIGHMEM |
27 | static __init int init_emergency_pool(void) |
28 | { |
29 | struct sysinfo i; |
30 | si_meminfo(&i); |
31 | si_swapinfo(&i); |
32 | |
33 | if (!i.totalhigh) |
34 | return 0; |
35 | |
36 | page_pool = mempool_create_page_pool(POOL_SIZE, 0); |
37 | BUG_ON(!page_pool); |
38 | printk("highmem bounce pool size: %d pages\n", POOL_SIZE); |
39 | |
40 | return 0; |
41 | } |
42 | |
43 | __initcall(init_emergency_pool); |
44 | |
45 | /* |
46 | * highmem version, map in to vec |
47 | */ |
48 | static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) |
49 | { |
50 | unsigned long flags; |
51 | unsigned char *vto; |
52 | |
53 | local_irq_save(flags); |
54 | vto = kmap_atomic(to->bv_page, KM_BOUNCE_READ); |
55 | memcpy(vto + to->bv_offset, vfrom, to->bv_len); |
56 | kunmap_atomic(vto, KM_BOUNCE_READ); |
57 | local_irq_restore(flags); |
58 | } |
59 | |
60 | #else /* CONFIG_HIGHMEM */ |
61 | |
62 | #define bounce_copy_vec(to, vfrom) \ |
63 | memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) |
64 | |
65 | #endif /* CONFIG_HIGHMEM */ |
66 | |
67 | /* |
68 | * allocate pages in the DMA region for the ISA pool |
69 | */ |
70 | static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) |
71 | { |
72 | return mempool_alloc_pages(gfp_mask | GFP_DMA, data); |
73 | } |
74 | |
75 | /* |
76 | * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA |
77 | * as the max address, so check if the pool has already been created. |
78 | */ |
79 | int init_emergency_isa_pool(void) |
80 | { |
81 | if (isa_page_pool) |
82 | return 0; |
83 | |
84 | isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, |
85 | mempool_free_pages, (void *) 0); |
86 | BUG_ON(!isa_page_pool); |
87 | |
88 | printk("isa bounce pool size: %d pages\n", ISA_POOL_SIZE); |
89 | return 0; |
90 | } |
91 | |
92 | /* |
93 | * Simple bounce buffer support for highmem pages. Depending on the |
94 | * queue gfp mask set, *to may or may not be a highmem page. kmap it |
95 | * always, it will do the Right Thing |
96 | */ |
97 | static void copy_to_high_bio_irq(struct bio *to, struct bio *from) |
98 | { |
99 | unsigned char *vfrom; |
100 | struct bio_vec *tovec, *fromvec; |
101 | int i; |
102 | |
103 | __bio_for_each_segment(tovec, to, i, 0) { |
104 | fromvec = from->bi_io_vec + i; |
105 | |
106 | /* |
107 | * not bounced |
108 | */ |
109 | if (tovec->bv_page == fromvec->bv_page) |
110 | continue; |
111 | |
112 | /* |
113 | * fromvec->bv_offset and fromvec->bv_len might have been |
114 | * modified by the block layer, so use the original copy, |
115 | * bounce_copy_vec already uses tovec->bv_len |
116 | */ |
117 | vfrom = page_address(fromvec->bv_page) + tovec->bv_offset; |
118 | |
119 | bounce_copy_vec(tovec, vfrom); |
120 | flush_dcache_page(tovec->bv_page); |
121 | } |
122 | } |
123 | |
124 | static void bounce_end_io(struct bio *bio, mempool_t *pool, int err) |
125 | { |
126 | struct bio *bio_orig = bio->bi_private; |
127 | struct bio_vec *bvec, *org_vec; |
128 | int i; |
129 | |
130 | if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags)) |
131 | set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags); |
132 | |
133 | /* |
134 | * free up bounce indirect pages used |
135 | */ |
136 | __bio_for_each_segment(bvec, bio, i, 0) { |
137 | org_vec = bio_orig->bi_io_vec + i; |
138 | if (bvec->bv_page == org_vec->bv_page) |
139 | continue; |
140 | |
141 | dec_zone_page_state(bvec->bv_page, NR_BOUNCE); |
142 | mempool_free(bvec->bv_page, pool); |
143 | } |
144 | |
145 | bio_endio(bio_orig, err); |
146 | bio_put(bio); |
147 | } |
148 | |
149 | static void bounce_end_io_write(struct bio *bio, int err) |
150 | { |
151 | bounce_end_io(bio, page_pool, err); |
152 | } |
153 | |
154 | static void bounce_end_io_write_isa(struct bio *bio, int err) |
155 | { |
156 | |
157 | bounce_end_io(bio, isa_page_pool, err); |
158 | } |
159 | |
160 | static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err) |
161 | { |
162 | struct bio *bio_orig = bio->bi_private; |
163 | |
164 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) |
165 | copy_to_high_bio_irq(bio_orig, bio); |
166 | |
167 | bounce_end_io(bio, pool, err); |
168 | } |
169 | |
170 | static void bounce_end_io_read(struct bio *bio, int err) |
171 | { |
172 | __bounce_end_io_read(bio, page_pool, err); |
173 | } |
174 | |
175 | static void bounce_end_io_read_isa(struct bio *bio, int err) |
176 | { |
177 | __bounce_end_io_read(bio, isa_page_pool, err); |
178 | } |
179 | |
180 | static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, |
181 | mempool_t *pool) |
182 | { |
183 | struct page *page; |
184 | struct bio *bio = NULL; |
185 | int i, rw = bio_data_dir(*bio_orig); |
186 | struct bio_vec *to, *from; |
187 | |
188 | bio_for_each_segment(from, *bio_orig, i) { |
189 | page = from->bv_page; |
190 | |
191 | /* |
192 | * is destination page below bounce pfn? |
193 | */ |
194 | if (page_to_pfn(page) <= queue_bounce_pfn(q)) |
195 | continue; |
196 | |
197 | /* |
198 | * irk, bounce it |
199 | */ |
200 | if (!bio) { |
201 | unsigned int cnt = (*bio_orig)->bi_vcnt; |
202 | |
203 | bio = bio_alloc(GFP_NOIO, cnt); |
204 | memset(bio->bi_io_vec, 0, cnt * sizeof(struct bio_vec)); |
205 | } |
206 | |
207 | |
208 | to = bio->bi_io_vec + i; |
209 | |
210 | to->bv_page = mempool_alloc(pool, q->bounce_gfp); |
211 | to->bv_len = from->bv_len; |
212 | to->bv_offset = from->bv_offset; |
213 | inc_zone_page_state(to->bv_page, NR_BOUNCE); |
214 | |
215 | if (rw == WRITE) { |
216 | char *vto, *vfrom; |
217 | |
218 | flush_dcache_page(from->bv_page); |
219 | vto = page_address(to->bv_page) + to->bv_offset; |
220 | vfrom = kmap(from->bv_page) + from->bv_offset; |
221 | memcpy(vto, vfrom, to->bv_len); |
222 | kunmap(from->bv_page); |
223 | } |
224 | } |
225 | |
226 | /* |
227 | * no pages bounced |
228 | */ |
229 | if (!bio) |
230 | return; |
231 | |
232 | trace_block_bio_bounce(q, *bio_orig); |
233 | |
234 | /* |
235 | * at least one page was bounced, fill in possible non-highmem |
236 | * pages |
237 | */ |
238 | __bio_for_each_segment(from, *bio_orig, i, 0) { |
239 | to = bio_iovec_idx(bio, i); |
240 | if (!to->bv_page) { |
241 | to->bv_page = from->bv_page; |
242 | to->bv_len = from->bv_len; |
243 | to->bv_offset = from->bv_offset; |
244 | } |
245 | } |
246 | |
247 | bio->bi_bdev = (*bio_orig)->bi_bdev; |
248 | bio->bi_flags |= (1 << BIO_BOUNCED); |
249 | bio->bi_sector = (*bio_orig)->bi_sector; |
250 | bio->bi_rw = (*bio_orig)->bi_rw; |
251 | |
252 | bio->bi_vcnt = (*bio_orig)->bi_vcnt; |
253 | bio->bi_idx = (*bio_orig)->bi_idx; |
254 | bio->bi_size = (*bio_orig)->bi_size; |
255 | |
256 | if (pool == page_pool) { |
257 | bio->bi_end_io = bounce_end_io_write; |
258 | if (rw == READ) |
259 | bio->bi_end_io = bounce_end_io_read; |
260 | } else { |
261 | bio->bi_end_io = bounce_end_io_write_isa; |
262 | if (rw == READ) |
263 | bio->bi_end_io = bounce_end_io_read_isa; |
264 | } |
265 | |
266 | bio->bi_private = *bio_orig; |
267 | *bio_orig = bio; |
268 | } |
269 | |
270 | void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) |
271 | { |
272 | mempool_t *pool; |
273 | |
274 | /* |
275 | * Data-less bio, nothing to bounce |
276 | */ |
277 | if (!bio_has_data(*bio_orig)) |
278 | return; |
279 | |
280 | /* |
281 | * for non-isa bounce case, just check if the bounce pfn is equal |
282 | * to or bigger than the highest pfn in the system -- in that case, |
283 | * don't waste time iterating over bio segments |
284 | */ |
285 | if (!(q->bounce_gfp & GFP_DMA)) { |
286 | if (queue_bounce_pfn(q) >= blk_max_pfn) |
287 | return; |
288 | pool = page_pool; |
289 | } else { |
290 | BUG_ON(!isa_page_pool); |
291 | pool = isa_page_pool; |
292 | } |
293 | |
294 | /* |
295 | * slow path |
296 | */ |
297 | __blk_queue_bounce(q, bio_orig, pool); |
298 | } |
299 | |
300 | EXPORT_SYMBOL(blk_queue_bounce); |
301 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9