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Commit | Line | Data |
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831058de DH |
1 | /* bounce buffer handling for block devices |
2 | * | |
3 | * - Split from highmem.c | |
4 | */ | |
5 | ||
b1de0d13 MH |
6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
7 | ||
831058de | 8 | #include <linux/mm.h> |
b95f1b31 | 9 | #include <linux/export.h> |
831058de | 10 | #include <linux/swap.h> |
5a0e3ad6 | 11 | #include <linux/gfp.h> |
831058de DH |
12 | #include <linux/bio.h> |
13 | #include <linux/pagemap.h> | |
14 | #include <linux/mempool.h> | |
15 | #include <linux/blkdev.h> | |
66114cad | 16 | #include <linux/backing-dev.h> |
831058de DH |
17 | #include <linux/init.h> |
18 | #include <linux/hash.h> | |
19 | #include <linux/highmem.h> | |
3bcfeaf9 | 20 | #include <linux/bootmem.h> |
b1de0d13 | 21 | #include <linux/printk.h> |
831058de DH |
22 | #include <asm/tlbflush.h> |
23 | ||
55782138 LZ |
24 | #include <trace/events/block.h> |
25 | ||
831058de DH |
26 | #define POOL_SIZE 64 |
27 | #define ISA_POOL_SIZE 16 | |
28 | ||
e0fc443a | 29 | static struct bio_set *bounce_bio_set, *bounce_bio_split; |
831058de DH |
30 | static mempool_t *page_pool, *isa_page_pool; |
31 | ||
f1006257 | 32 | #if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL) |
831058de DH |
33 | static __init int init_emergency_pool(void) |
34 | { | |
f1006257 | 35 | #if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG) |
3bcfeaf9 | 36 | if (max_pfn <= max_low_pfn) |
831058de | 37 | return 0; |
3bcfeaf9 | 38 | #endif |
831058de DH |
39 | |
40 | page_pool = mempool_create_page_pool(POOL_SIZE, 0); | |
41 | BUG_ON(!page_pool); | |
b1de0d13 | 42 | pr_info("pool size: %d pages\n", POOL_SIZE); |
831058de | 43 | |
a8821f3f N |
44 | bounce_bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); |
45 | BUG_ON(!bounce_bio_set); | |
46 | if (bioset_integrity_create(bounce_bio_set, BIO_POOL_SIZE)) | |
47 | BUG_ON(1); | |
48 | ||
49 | bounce_bio_split = bioset_create(BIO_POOL_SIZE, 0, 0); | |
50 | BUG_ON(!bounce_bio_split); | |
51 | ||
831058de DH |
52 | return 0; |
53 | } | |
54 | ||
55 | __initcall(init_emergency_pool); | |
f1006257 | 56 | #endif |
831058de | 57 | |
f1006257 | 58 | #ifdef CONFIG_HIGHMEM |
831058de DH |
59 | /* |
60 | * highmem version, map in to vec | |
61 | */ | |
62 | static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) | |
63 | { | |
64 | unsigned long flags; | |
65 | unsigned char *vto; | |
66 | ||
67 | local_irq_save(flags); | |
9b04c5fe | 68 | vto = kmap_atomic(to->bv_page); |
831058de | 69 | memcpy(vto + to->bv_offset, vfrom, to->bv_len); |
9b04c5fe | 70 | kunmap_atomic(vto); |
831058de DH |
71 | local_irq_restore(flags); |
72 | } | |
73 | ||
74 | #else /* CONFIG_HIGHMEM */ | |
75 | ||
76 | #define bounce_copy_vec(to, vfrom) \ | |
77 | memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) | |
78 | ||
79 | #endif /* CONFIG_HIGHMEM */ | |
80 | ||
81 | /* | |
82 | * allocate pages in the DMA region for the ISA pool | |
83 | */ | |
84 | static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) | |
85 | { | |
86 | return mempool_alloc_pages(gfp_mask | GFP_DMA, data); | |
87 | } | |
88 | ||
89 | /* | |
90 | * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA | |
91 | * as the max address, so check if the pool has already been created. | |
92 | */ | |
93 | int init_emergency_isa_pool(void) | |
94 | { | |
95 | if (isa_page_pool) | |
96 | return 0; | |
97 | ||
98 | isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, | |
99 | mempool_free_pages, (void *) 0); | |
100 | BUG_ON(!isa_page_pool); | |
101 | ||
b1de0d13 | 102 | pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE); |
831058de DH |
103 | return 0; |
104 | } | |
105 | ||
106 | /* | |
107 | * Simple bounce buffer support for highmem pages. Depending on the | |
108 | * queue gfp mask set, *to may or may not be a highmem page. kmap it | |
109 | * always, it will do the Right Thing | |
110 | */ | |
111 | static void copy_to_high_bio_irq(struct bio *to, struct bio *from) | |
112 | { | |
113 | unsigned char *vfrom; | |
7988613b KO |
114 | struct bio_vec tovec, *fromvec = from->bi_io_vec; |
115 | struct bvec_iter iter; | |
116 | ||
117 | bio_for_each_segment(tovec, to, iter) { | |
118 | if (tovec.bv_page != fromvec->bv_page) { | |
119 | /* | |
120 | * fromvec->bv_offset and fromvec->bv_len might have | |
121 | * been modified by the block layer, so use the original | |
122 | * copy, bounce_copy_vec already uses tovec->bv_len | |
123 | */ | |
124 | vfrom = page_address(fromvec->bv_page) + | |
125 | tovec.bv_offset; | |
126 | ||
127 | bounce_copy_vec(&tovec, vfrom); | |
128 | flush_dcache_page(tovec.bv_page); | |
129 | } | |
831058de | 130 | |
7988613b | 131 | fromvec++; |
831058de DH |
132 | } |
133 | } | |
134 | ||
4246a0b6 | 135 | static void bounce_end_io(struct bio *bio, mempool_t *pool) |
831058de DH |
136 | { |
137 | struct bio *bio_orig = bio->bi_private; | |
138 | struct bio_vec *bvec, *org_vec; | |
139 | int i; | |
99451879 | 140 | int start = bio_orig->bi_iter.bi_idx; |
831058de | 141 | |
831058de DH |
142 | /* |
143 | * free up bounce indirect pages used | |
144 | */ | |
d74c6d51 | 145 | bio_for_each_segment_all(bvec, bio, i) { |
99451879 ML |
146 | org_vec = bio_orig->bi_io_vec + i + start; |
147 | ||
831058de DH |
148 | if (bvec->bv_page == org_vec->bv_page) |
149 | continue; | |
150 | ||
151 | dec_zone_page_state(bvec->bv_page, NR_BOUNCE); | |
152 | mempool_free(bvec->bv_page, pool); | |
153 | } | |
154 | ||
4e4cbee9 | 155 | bio_orig->bi_status = bio->bi_status; |
4246a0b6 | 156 | bio_endio(bio_orig); |
831058de DH |
157 | bio_put(bio); |
158 | } | |
159 | ||
4246a0b6 | 160 | static void bounce_end_io_write(struct bio *bio) |
831058de | 161 | { |
4246a0b6 | 162 | bounce_end_io(bio, page_pool); |
831058de DH |
163 | } |
164 | ||
4246a0b6 | 165 | static void bounce_end_io_write_isa(struct bio *bio) |
831058de | 166 | { |
831058de | 167 | |
4246a0b6 | 168 | bounce_end_io(bio, isa_page_pool); |
831058de DH |
169 | } |
170 | ||
4246a0b6 | 171 | static void __bounce_end_io_read(struct bio *bio, mempool_t *pool) |
831058de DH |
172 | { |
173 | struct bio *bio_orig = bio->bi_private; | |
174 | ||
4e4cbee9 | 175 | if (!bio->bi_status) |
831058de DH |
176 | copy_to_high_bio_irq(bio_orig, bio); |
177 | ||
4246a0b6 | 178 | bounce_end_io(bio, pool); |
831058de DH |
179 | } |
180 | ||
4246a0b6 | 181 | static void bounce_end_io_read(struct bio *bio) |
831058de | 182 | { |
4246a0b6 | 183 | __bounce_end_io_read(bio, page_pool); |
831058de DH |
184 | } |
185 | ||
4246a0b6 | 186 | static void bounce_end_io_read_isa(struct bio *bio) |
831058de | 187 | { |
4246a0b6 | 188 | __bounce_end_io_read(bio, isa_page_pool); |
831058de DH |
189 | } |
190 | ||
165125e1 | 191 | static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, |
a3ad0a9d | 192 | mempool_t *pool) |
831058de | 193 | { |
6bc454d1 KO |
194 | struct bio *bio; |
195 | int rw = bio_data_dir(*bio_orig); | |
7988613b KO |
196 | struct bio_vec *to, from; |
197 | struct bvec_iter iter; | |
a8821f3f N |
198 | unsigned i = 0; |
199 | bool bounce = false; | |
200 | int sectors = 0; | |
831058de | 201 | |
a8821f3f N |
202 | bio_for_each_segment(from, *bio_orig, iter) { |
203 | if (i++ < BIO_MAX_PAGES) | |
204 | sectors += from.bv_len >> 9; | |
7988613b | 205 | if (page_to_pfn(from.bv_page) > queue_bounce_pfn(q)) |
a8821f3f N |
206 | bounce = true; |
207 | } | |
208 | if (!bounce) | |
209 | return; | |
210 | ||
211 | if (sectors < bio_sectors(*bio_orig)) { | |
212 | bio = bio_split(*bio_orig, sectors, GFP_NOIO, bounce_bio_split); | |
213 | bio_chain(bio, *bio_orig); | |
214 | generic_make_request(*bio_orig); | |
215 | *bio_orig = bio; | |
216 | } | |
217 | bio = bio_clone_bioset(*bio_orig, GFP_NOIO, bounce_bio_set); | |
831058de | 218 | |
cb34e057 | 219 | bio_for_each_segment_all(to, bio, i) { |
6bc454d1 | 220 | struct page *page = to->bv_page; |
f735b5ee | 221 | |
a3ad0a9d | 222 | if (page_to_pfn(page) <= queue_bounce_pfn(q)) |
6bc454d1 | 223 | continue; |
831058de | 224 | |
6bc454d1 | 225 | to->bv_page = mempool_alloc(pool, q->bounce_gfp); |
393a3397 | 226 | inc_zone_page_state(to->bv_page, NR_BOUNCE); |
831058de DH |
227 | |
228 | if (rw == WRITE) { | |
229 | char *vto, *vfrom; | |
230 | ||
6bc454d1 KO |
231 | flush_dcache_page(page); |
232 | ||
831058de | 233 | vto = page_address(to->bv_page) + to->bv_offset; |
6bc454d1 | 234 | vfrom = kmap_atomic(page) + to->bv_offset; |
831058de | 235 | memcpy(vto, vfrom, to->bv_len); |
6bc454d1 | 236 | kunmap_atomic(vfrom); |
831058de DH |
237 | } |
238 | } | |
239 | ||
5f3ea37c | 240 | trace_block_bio_bounce(q, *bio_orig); |
c43a5082 | 241 | |
831058de | 242 | bio->bi_flags |= (1 << BIO_BOUNCED); |
831058de DH |
243 | |
244 | if (pool == page_pool) { | |
245 | bio->bi_end_io = bounce_end_io_write; | |
246 | if (rw == READ) | |
247 | bio->bi_end_io = bounce_end_io_read; | |
248 | } else { | |
249 | bio->bi_end_io = bounce_end_io_write_isa; | |
250 | if (rw == READ) | |
251 | bio->bi_end_io = bounce_end_io_read_isa; | |
252 | } | |
253 | ||
254 | bio->bi_private = *bio_orig; | |
255 | *bio_orig = bio; | |
256 | } | |
257 | ||
165125e1 | 258 | void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) |
831058de DH |
259 | { |
260 | mempool_t *pool; | |
261 | ||
bf2de6f5 JA |
262 | /* |
263 | * Data-less bio, nothing to bounce | |
264 | */ | |
36144077 | 265 | if (!bio_has_data(*bio_orig)) |
bf2de6f5 JA |
266 | return; |
267 | ||
831058de DH |
268 | /* |
269 | * for non-isa bounce case, just check if the bounce pfn is equal | |
270 | * to or bigger than the highest pfn in the system -- in that case, | |
271 | * don't waste time iterating over bio segments | |
272 | */ | |
273 | if (!(q->bounce_gfp & GFP_DMA)) { | |
a3ad0a9d | 274 | if (queue_bounce_pfn(q) >= blk_max_pfn) |
831058de DH |
275 | return; |
276 | pool = page_pool; | |
277 | } else { | |
278 | BUG_ON(!isa_page_pool); | |
279 | pool = isa_page_pool; | |
280 | } | |
281 | ||
831058de DH |
282 | /* |
283 | * slow path | |
284 | */ | |
a3ad0a9d | 285 | __blk_queue_bounce(q, bio_orig, pool); |
831058de DH |
286 | } |
287 | ||
288 | EXPORT_SYMBOL(blk_queue_bounce); |