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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
831058de DH |
2 | /* bounce buffer handling for block devices |
3 | * | |
4 | * - Split from highmem.c | |
5 | */ | |
6 | ||
b1de0d13 MH |
7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
8 | ||
831058de | 9 | #include <linux/mm.h> |
b95f1b31 | 10 | #include <linux/export.h> |
831058de | 11 | #include <linux/swap.h> |
5a0e3ad6 | 12 | #include <linux/gfp.h> |
831058de DH |
13 | #include <linux/bio.h> |
14 | #include <linux/pagemap.h> | |
15 | #include <linux/mempool.h> | |
16 | #include <linux/blkdev.h> | |
66114cad | 17 | #include <linux/backing-dev.h> |
831058de DH |
18 | #include <linux/init.h> |
19 | #include <linux/hash.h> | |
20 | #include <linux/highmem.h> | |
3bcfeaf9 | 21 | #include <linux/bootmem.h> |
b1de0d13 | 22 | #include <linux/printk.h> |
831058de DH |
23 | #include <asm/tlbflush.h> |
24 | ||
55782138 | 25 | #include <trace/events/block.h> |
3bce016a | 26 | #include "blk.h" |
55782138 | 27 | |
831058de DH |
28 | #define POOL_SIZE 64 |
29 | #define ISA_POOL_SIZE 16 | |
30 | ||
e0fc443a | 31 | static struct bio_set *bounce_bio_set, *bounce_bio_split; |
831058de DH |
32 | static mempool_t *page_pool, *isa_page_pool; |
33 | ||
f1006257 | 34 | #if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL) |
831058de DH |
35 | static __init int init_emergency_pool(void) |
36 | { | |
f1006257 | 37 | #if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG) |
3bcfeaf9 | 38 | if (max_pfn <= max_low_pfn) |
831058de | 39 | return 0; |
3bcfeaf9 | 40 | #endif |
831058de DH |
41 | |
42 | page_pool = mempool_create_page_pool(POOL_SIZE, 0); | |
43 | BUG_ON(!page_pool); | |
b1de0d13 | 44 | pr_info("pool size: %d pages\n", POOL_SIZE); |
831058de | 45 | |
a8821f3f N |
46 | bounce_bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); |
47 | BUG_ON(!bounce_bio_set); | |
48 | if (bioset_integrity_create(bounce_bio_set, BIO_POOL_SIZE)) | |
49 | BUG_ON(1); | |
50 | ||
51 | bounce_bio_split = bioset_create(BIO_POOL_SIZE, 0, 0); | |
52 | BUG_ON(!bounce_bio_split); | |
53 | ||
831058de DH |
54 | return 0; |
55 | } | |
56 | ||
57 | __initcall(init_emergency_pool); | |
f1006257 | 58 | #endif |
831058de | 59 | |
f1006257 | 60 | #ifdef CONFIG_HIGHMEM |
831058de DH |
61 | /* |
62 | * highmem version, map in to vec | |
63 | */ | |
64 | static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) | |
65 | { | |
66 | unsigned long flags; | |
67 | unsigned char *vto; | |
68 | ||
69 | local_irq_save(flags); | |
9b04c5fe | 70 | vto = kmap_atomic(to->bv_page); |
831058de | 71 | memcpy(vto + to->bv_offset, vfrom, to->bv_len); |
9b04c5fe | 72 | kunmap_atomic(vto); |
831058de DH |
73 | local_irq_restore(flags); |
74 | } | |
75 | ||
76 | #else /* CONFIG_HIGHMEM */ | |
77 | ||
78 | #define bounce_copy_vec(to, vfrom) \ | |
79 | memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) | |
80 | ||
81 | #endif /* CONFIG_HIGHMEM */ | |
82 | ||
83 | /* | |
84 | * allocate pages in the DMA region for the ISA pool | |
85 | */ | |
86 | static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) | |
87 | { | |
88 | return mempool_alloc_pages(gfp_mask | GFP_DMA, data); | |
89 | } | |
90 | ||
91 | /* | |
92 | * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA | |
93 | * as the max address, so check if the pool has already been created. | |
94 | */ | |
95 | int init_emergency_isa_pool(void) | |
96 | { | |
97 | if (isa_page_pool) | |
98 | return 0; | |
99 | ||
100 | isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, | |
101 | mempool_free_pages, (void *) 0); | |
102 | BUG_ON(!isa_page_pool); | |
103 | ||
b1de0d13 | 104 | pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE); |
831058de DH |
105 | return 0; |
106 | } | |
107 | ||
108 | /* | |
109 | * Simple bounce buffer support for highmem pages. Depending on the | |
110 | * queue gfp mask set, *to may or may not be a highmem page. kmap it | |
111 | * always, it will do the Right Thing | |
112 | */ | |
113 | static void copy_to_high_bio_irq(struct bio *to, struct bio *from) | |
114 | { | |
115 | unsigned char *vfrom; | |
7988613b KO |
116 | struct bio_vec tovec, *fromvec = from->bi_io_vec; |
117 | struct bvec_iter iter; | |
118 | ||
119 | bio_for_each_segment(tovec, to, iter) { | |
120 | if (tovec.bv_page != fromvec->bv_page) { | |
121 | /* | |
122 | * fromvec->bv_offset and fromvec->bv_len might have | |
123 | * been modified by the block layer, so use the original | |
124 | * copy, bounce_copy_vec already uses tovec->bv_len | |
125 | */ | |
126 | vfrom = page_address(fromvec->bv_page) + | |
127 | tovec.bv_offset; | |
128 | ||
129 | bounce_copy_vec(&tovec, vfrom); | |
130 | flush_dcache_page(tovec.bv_page); | |
131 | } | |
831058de | 132 | |
7988613b | 133 | fromvec++; |
831058de DH |
134 | } |
135 | } | |
136 | ||
4246a0b6 | 137 | static void bounce_end_io(struct bio *bio, mempool_t *pool) |
831058de DH |
138 | { |
139 | struct bio *bio_orig = bio->bi_private; | |
140 | struct bio_vec *bvec, *org_vec; | |
141 | int i; | |
99451879 | 142 | int start = bio_orig->bi_iter.bi_idx; |
831058de | 143 | |
831058de DH |
144 | /* |
145 | * free up bounce indirect pages used | |
146 | */ | |
d74c6d51 | 147 | bio_for_each_segment_all(bvec, bio, i) { |
99451879 ML |
148 | org_vec = bio_orig->bi_io_vec + i + start; |
149 | ||
831058de DH |
150 | if (bvec->bv_page == org_vec->bv_page) |
151 | continue; | |
152 | ||
153 | dec_zone_page_state(bvec->bv_page, NR_BOUNCE); | |
154 | mempool_free(bvec->bv_page, pool); | |
155 | } | |
156 | ||
4e4cbee9 | 157 | bio_orig->bi_status = bio->bi_status; |
4246a0b6 | 158 | bio_endio(bio_orig); |
831058de DH |
159 | bio_put(bio); |
160 | } | |
161 | ||
4246a0b6 | 162 | static void bounce_end_io_write(struct bio *bio) |
831058de | 163 | { |
4246a0b6 | 164 | bounce_end_io(bio, page_pool); |
831058de DH |
165 | } |
166 | ||
4246a0b6 | 167 | static void bounce_end_io_write_isa(struct bio *bio) |
831058de | 168 | { |
831058de | 169 | |
4246a0b6 | 170 | bounce_end_io(bio, isa_page_pool); |
831058de DH |
171 | } |
172 | ||
4246a0b6 | 173 | static void __bounce_end_io_read(struct bio *bio, mempool_t *pool) |
831058de DH |
174 | { |
175 | struct bio *bio_orig = bio->bi_private; | |
176 | ||
4e4cbee9 | 177 | if (!bio->bi_status) |
831058de DH |
178 | copy_to_high_bio_irq(bio_orig, bio); |
179 | ||
4246a0b6 | 180 | bounce_end_io(bio, pool); |
831058de DH |
181 | } |
182 | ||
4246a0b6 | 183 | static void bounce_end_io_read(struct bio *bio) |
831058de | 184 | { |
4246a0b6 | 185 | __bounce_end_io_read(bio, page_pool); |
831058de DH |
186 | } |
187 | ||
4246a0b6 | 188 | static void bounce_end_io_read_isa(struct bio *bio) |
831058de | 189 | { |
4246a0b6 | 190 | __bounce_end_io_read(bio, isa_page_pool); |
831058de DH |
191 | } |
192 | ||
165125e1 | 193 | static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, |
a3ad0a9d | 194 | mempool_t *pool) |
831058de | 195 | { |
6bc454d1 KO |
196 | struct bio *bio; |
197 | int rw = bio_data_dir(*bio_orig); | |
7988613b KO |
198 | struct bio_vec *to, from; |
199 | struct bvec_iter iter; | |
a8821f3f N |
200 | unsigned i = 0; |
201 | bool bounce = false; | |
202 | int sectors = 0; | |
831058de | 203 | |
a8821f3f N |
204 | bio_for_each_segment(from, *bio_orig, iter) { |
205 | if (i++ < BIO_MAX_PAGES) | |
206 | sectors += from.bv_len >> 9; | |
1c4bc3ab | 207 | if (page_to_pfn(from.bv_page) > q->limits.bounce_pfn) |
a8821f3f N |
208 | bounce = true; |
209 | } | |
210 | if (!bounce) | |
211 | return; | |
212 | ||
213 | if (sectors < bio_sectors(*bio_orig)) { | |
214 | bio = bio_split(*bio_orig, sectors, GFP_NOIO, bounce_bio_split); | |
215 | bio_chain(bio, *bio_orig); | |
216 | generic_make_request(*bio_orig); | |
217 | *bio_orig = bio; | |
218 | } | |
219 | bio = bio_clone_bioset(*bio_orig, GFP_NOIO, bounce_bio_set); | |
831058de | 220 | |
cb34e057 | 221 | bio_for_each_segment_all(to, bio, i) { |
6bc454d1 | 222 | struct page *page = to->bv_page; |
f735b5ee | 223 | |
1c4bc3ab | 224 | if (page_to_pfn(page) <= q->limits.bounce_pfn) |
6bc454d1 | 225 | continue; |
831058de | 226 | |
6bc454d1 | 227 | to->bv_page = mempool_alloc(pool, q->bounce_gfp); |
393a3397 | 228 | inc_zone_page_state(to->bv_page, NR_BOUNCE); |
831058de DH |
229 | |
230 | if (rw == WRITE) { | |
231 | char *vto, *vfrom; | |
232 | ||
6bc454d1 KO |
233 | flush_dcache_page(page); |
234 | ||
831058de | 235 | vto = page_address(to->bv_page) + to->bv_offset; |
6bc454d1 | 236 | vfrom = kmap_atomic(page) + to->bv_offset; |
831058de | 237 | memcpy(vto, vfrom, to->bv_len); |
6bc454d1 | 238 | kunmap_atomic(vfrom); |
831058de DH |
239 | } |
240 | } | |
241 | ||
5f3ea37c | 242 | trace_block_bio_bounce(q, *bio_orig); |
c43a5082 | 243 | |
831058de | 244 | bio->bi_flags |= (1 << BIO_BOUNCED); |
831058de DH |
245 | |
246 | if (pool == page_pool) { | |
247 | bio->bi_end_io = bounce_end_io_write; | |
248 | if (rw == READ) | |
249 | bio->bi_end_io = bounce_end_io_read; | |
250 | } else { | |
251 | bio->bi_end_io = bounce_end_io_write_isa; | |
252 | if (rw == READ) | |
253 | bio->bi_end_io = bounce_end_io_read_isa; | |
254 | } | |
255 | ||
256 | bio->bi_private = *bio_orig; | |
257 | *bio_orig = bio; | |
258 | } | |
259 | ||
165125e1 | 260 | void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) |
831058de DH |
261 | { |
262 | mempool_t *pool; | |
263 | ||
bf2de6f5 JA |
264 | /* |
265 | * Data-less bio, nothing to bounce | |
266 | */ | |
36144077 | 267 | if (!bio_has_data(*bio_orig)) |
bf2de6f5 JA |
268 | return; |
269 | ||
831058de DH |
270 | /* |
271 | * for non-isa bounce case, just check if the bounce pfn is equal | |
272 | * to or bigger than the highest pfn in the system -- in that case, | |
273 | * don't waste time iterating over bio segments | |
274 | */ | |
275 | if (!(q->bounce_gfp & GFP_DMA)) { | |
1c4bc3ab | 276 | if (q->limits.bounce_pfn >= blk_max_pfn) |
831058de DH |
277 | return; |
278 | pool = page_pool; | |
279 | } else { | |
280 | BUG_ON(!isa_page_pool); | |
281 | pool = isa_page_pool; | |
282 | } | |
283 | ||
831058de DH |
284 | /* |
285 | * slow path | |
286 | */ | |
a3ad0a9d | 287 | __blk_queue_bounce(q, bio_orig, pool); |
831058de | 288 | } |