Blame view
mm/bounce.c
6.41 KB
831058dec [PATCH] BLOCK: Se... |
1 2 3 4 5 6 |
/* bounce buffer handling for block devices * * - Split from highmem.c */ #include <linux/mm.h> |
b95f1b31b mm: Map most file... |
7 |
#include <linux/export.h> |
831058dec [PATCH] BLOCK: Se... |
8 |
#include <linux/swap.h> |
5a0e3ad6a include cleanup: ... |
9 |
#include <linux/gfp.h> |
831058dec [PATCH] BLOCK: Se... |
10 11 12 13 14 15 16 |
#include <linux/bio.h> #include <linux/pagemap.h> #include <linux/mempool.h> #include <linux/blkdev.h> #include <linux/init.h> #include <linux/hash.h> #include <linux/highmem.h> |
3bcfeaf93 block: initialize... |
17 |
#include <linux/bootmem.h> |
831058dec [PATCH] BLOCK: Se... |
18 |
#include <asm/tlbflush.h> |
55782138e tracing/events: c... |
19 |
#include <trace/events/block.h> |
831058dec [PATCH] BLOCK: Se... |
20 21 22 23 |
#define POOL_SIZE 64 #define ISA_POOL_SIZE 16 static mempool_t *page_pool, *isa_page_pool; |
f10062578 bounce: allow use... |
24 |
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL) |
831058dec [PATCH] BLOCK: Se... |
25 26 |
static __init int init_emergency_pool(void) { |
f10062578 bounce: allow use... |
27 |
#if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG) |
3bcfeaf93 block: initialize... |
28 |
if (max_pfn <= max_low_pfn) |
831058dec [PATCH] BLOCK: Se... |
29 |
return 0; |
3bcfeaf93 block: initialize... |
30 |
#endif |
831058dec [PATCH] BLOCK: Se... |
31 32 33 |
page_pool = mempool_create_page_pool(POOL_SIZE, 0); BUG_ON(!page_pool); |
f10062578 bounce: allow use... |
34 35 |
printk("bounce pool size: %d pages ", POOL_SIZE); |
831058dec [PATCH] BLOCK: Se... |
36 37 38 39 40 |
return 0; } __initcall(init_emergency_pool); |
f10062578 bounce: allow use... |
41 |
#endif |
831058dec [PATCH] BLOCK: Se... |
42 |
|
f10062578 bounce: allow use... |
43 |
#ifdef CONFIG_HIGHMEM |
831058dec [PATCH] BLOCK: Se... |
44 45 46 47 48 49 50 51 52 |
/* * highmem version, map in to vec */ static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) { unsigned long flags; unsigned char *vto; local_irq_save(flags); |
9b04c5fec mm: remove the se... |
53 |
vto = kmap_atomic(to->bv_page); |
831058dec [PATCH] BLOCK: Se... |
54 |
memcpy(vto + to->bv_offset, vfrom, to->bv_len); |
9b04c5fec mm: remove the se... |
55 |
kunmap_atomic(vto); |
831058dec [PATCH] BLOCK: Se... |
56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 |
local_irq_restore(flags); } #else /* CONFIG_HIGHMEM */ #define bounce_copy_vec(to, vfrom) \ memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) #endif /* CONFIG_HIGHMEM */ /* * allocate pages in the DMA region for the ISA pool */ static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) { return mempool_alloc_pages(gfp_mask | GFP_DMA, data); } /* * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA * as the max address, so check if the pool has already been created. */ int init_emergency_isa_pool(void) { if (isa_page_pool) return 0; isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, mempool_free_pages, (void *) 0); BUG_ON(!isa_page_pool); printk("isa bounce pool size: %d pages ", ISA_POOL_SIZE); return 0; } /* * Simple bounce buffer support for highmem pages. Depending on the * queue gfp mask set, *to may or may not be a highmem page. kmap it * always, it will do the Right Thing */ static void copy_to_high_bio_irq(struct bio *to, struct bio *from) { unsigned char *vfrom; |
7988613b0 block: Convert bi... |
100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 |
struct bio_vec tovec, *fromvec = from->bi_io_vec; struct bvec_iter iter; bio_for_each_segment(tovec, to, iter) { if (tovec.bv_page != fromvec->bv_page) { /* * fromvec->bv_offset and fromvec->bv_len might have * been modified by the block layer, so use the original * copy, bounce_copy_vec already uses tovec->bv_len */ vfrom = page_address(fromvec->bv_page) + tovec.bv_offset; bounce_copy_vec(&tovec, vfrom); flush_dcache_page(tovec.bv_page); } |
831058dec [PATCH] BLOCK: Se... |
116 |
|
7988613b0 block: Convert bi... |
117 |
fromvec++; |
831058dec [PATCH] BLOCK: Se... |
118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 |
} } static void bounce_end_io(struct bio *bio, mempool_t *pool, int err) { struct bio *bio_orig = bio->bi_private; struct bio_vec *bvec, *org_vec; int i; if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags)) set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags); /* * free up bounce indirect pages used */ |
d74c6d514 block: Add bio_fo... |
133 |
bio_for_each_segment_all(bvec, bio, i) { |
831058dec [PATCH] BLOCK: Se... |
134 135 136 137 138 139 140 |
org_vec = bio_orig->bi_io_vec + i; if (bvec->bv_page == org_vec->bv_page) continue; dec_zone_page_state(bvec->bv_page, NR_BOUNCE); mempool_free(bvec->bv_page, pool); } |
6712ecf8f Drop 'size' argum... |
141 |
bio_endio(bio_orig, err); |
831058dec [PATCH] BLOCK: Se... |
142 143 |
bio_put(bio); } |
6712ecf8f Drop 'size' argum... |
144 |
static void bounce_end_io_write(struct bio *bio, int err) |
831058dec [PATCH] BLOCK: Se... |
145 |
{ |
831058dec [PATCH] BLOCK: Se... |
146 |
bounce_end_io(bio, page_pool, err); |
831058dec [PATCH] BLOCK: Se... |
147 |
} |
6712ecf8f Drop 'size' argum... |
148 |
static void bounce_end_io_write_isa(struct bio *bio, int err) |
831058dec [PATCH] BLOCK: Se... |
149 |
{ |
831058dec [PATCH] BLOCK: Se... |
150 151 |
bounce_end_io(bio, isa_page_pool, err); |
831058dec [PATCH] BLOCK: Se... |
152 153 154 155 156 157 158 159 160 161 162 |
} static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err) { struct bio *bio_orig = bio->bi_private; if (test_bit(BIO_UPTODATE, &bio->bi_flags)) copy_to_high_bio_irq(bio_orig, bio); bounce_end_io(bio, pool, err); } |
6712ecf8f Drop 'size' argum... |
163 |
static void bounce_end_io_read(struct bio *bio, int err) |
831058dec [PATCH] BLOCK: Se... |
164 |
{ |
831058dec [PATCH] BLOCK: Se... |
165 |
__bounce_end_io_read(bio, page_pool, err); |
831058dec [PATCH] BLOCK: Se... |
166 |
} |
6712ecf8f Drop 'size' argum... |
167 |
static void bounce_end_io_read_isa(struct bio *bio, int err) |
831058dec [PATCH] BLOCK: Se... |
168 |
{ |
831058dec [PATCH] BLOCK: Se... |
169 |
__bounce_end_io_read(bio, isa_page_pool, err); |
831058dec [PATCH] BLOCK: Se... |
170 |
} |
ffecfd1a7 block: optionally... |
171 172 173 |
#ifdef CONFIG_NEED_BOUNCE_POOL static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio) { |
ffecfd1a7 block: optionally... |
174 175 176 177 178 |
if (bio_data_dir(bio) != WRITE) return 0; if (!bdi_cap_stable_pages_required(&q->backing_dev_info)) return 0; |
713685111 mm: make snapshot... |
179 |
return test_bit(BIO_SNAP_STABLE, &bio->bi_flags); |
ffecfd1a7 block: optionally... |
180 181 182 183 184 185 186 |
} #else static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio) { return 0; } #endif /* CONFIG_NEED_BOUNCE_POOL */ |
165125e1e [BLOCK] Get rid o... |
187 |
static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, |
ffecfd1a7 block: optionally... |
188 |
mempool_t *pool, int force) |
831058dec [PATCH] BLOCK: Se... |
189 |
{ |
6bc454d15 bounce: Refactor ... |
190 191 |
struct bio *bio; int rw = bio_data_dir(*bio_orig); |
7988613b0 block: Convert bi... |
192 193 |
struct bio_vec *to, from; struct bvec_iter iter; |
6bc454d15 bounce: Refactor ... |
194 |
unsigned i; |
831058dec [PATCH] BLOCK: Se... |
195 |
|
83b2944fd mm/bounce.c: fix ... |
196 197 |
if (force) goto bounce; |
7988613b0 block: Convert bi... |
198 199 |
bio_for_each_segment(from, *bio_orig, iter) if (page_to_pfn(from.bv_page) > queue_bounce_pfn(q)) |
6bc454d15 bounce: Refactor ... |
200 |
goto bounce; |
831058dec [PATCH] BLOCK: Se... |
201 |
|
6bc454d15 bounce: Refactor ... |
202 203 204 |
return; bounce: bio = bio_clone_bioset(*bio_orig, GFP_NOIO, fs_bio_set); |
831058dec [PATCH] BLOCK: Se... |
205 |
|
cb34e057a block: Convert so... |
206 |
bio_for_each_segment_all(to, bio, i) { |
6bc454d15 bounce: Refactor ... |
207 |
struct page *page = to->bv_page; |
f735b5eeb bounce: don't rel... |
208 |
|
6bc454d15 bounce: Refactor ... |
209 210 |
if (page_to_pfn(page) <= queue_bounce_pfn(q) && !force) continue; |
831058dec [PATCH] BLOCK: Se... |
211 |
|
831058dec [PATCH] BLOCK: Se... |
212 |
inc_zone_page_state(to->bv_page, NR_BOUNCE); |
6bc454d15 bounce: Refactor ... |
213 |
to->bv_page = mempool_alloc(pool, q->bounce_gfp); |
831058dec [PATCH] BLOCK: Se... |
214 215 216 |
if (rw == WRITE) { char *vto, *vfrom; |
6bc454d15 bounce: Refactor ... |
217 |
flush_dcache_page(page); |
831058dec [PATCH] BLOCK: Se... |
218 |
vto = page_address(to->bv_page) + to->bv_offset; |
6bc454d15 bounce: Refactor ... |
219 |
vfrom = kmap_atomic(page) + to->bv_offset; |
831058dec [PATCH] BLOCK: Se... |
220 |
memcpy(vto, vfrom, to->bv_len); |
6bc454d15 bounce: Refactor ... |
221 |
kunmap_atomic(vfrom); |
831058dec [PATCH] BLOCK: Se... |
222 223 |
} } |
5f3ea37c7 blktrace: port to... |
224 |
trace_block_bio_bounce(q, *bio_orig); |
c43a5082a [PATCH] blktrace:... |
225 |
|
831058dec [PATCH] BLOCK: Se... |
226 |
bio->bi_flags |= (1 << BIO_BOUNCED); |
831058dec [PATCH] BLOCK: Se... |
227 228 229 230 231 232 233 234 235 236 237 238 239 240 |
if (pool == page_pool) { bio->bi_end_io = bounce_end_io_write; if (rw == READ) bio->bi_end_io = bounce_end_io_read; } else { bio->bi_end_io = bounce_end_io_write_isa; if (rw == READ) bio->bi_end_io = bounce_end_io_read_isa; } bio->bi_private = *bio_orig; *bio_orig = bio; } |
165125e1e [BLOCK] Get rid o... |
241 |
void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) |
831058dec [PATCH] BLOCK: Se... |
242 |
{ |
ffecfd1a7 block: optionally... |
243 |
int must_bounce; |
831058dec [PATCH] BLOCK: Se... |
244 245 246 |
mempool_t *pool; /* |
bf2de6f5a block: Initial su... |
247 248 |
* Data-less bio, nothing to bounce */ |
36144077b highmem: use bio_... |
249 |
if (!bio_has_data(*bio_orig)) |
bf2de6f5a block: Initial su... |
250 |
return; |
ffecfd1a7 block: optionally... |
251 |
must_bounce = must_snapshot_stable_pages(q, *bio_orig); |
bf2de6f5a block: Initial su... |
252 |
/* |
831058dec [PATCH] BLOCK: Se... |
253 254 255 256 257 |
* for non-isa bounce case, just check if the bounce pfn is equal * to or bigger than the highest pfn in the system -- in that case, * don't waste time iterating over bio segments */ if (!(q->bounce_gfp & GFP_DMA)) { |
ffecfd1a7 block: optionally... |
258 |
if (queue_bounce_pfn(q) >= blk_max_pfn && !must_bounce) |
831058dec [PATCH] BLOCK: Se... |
259 260 261 262 263 264 |
return; pool = page_pool; } else { BUG_ON(!isa_page_pool); pool = isa_page_pool; } |
831058dec [PATCH] BLOCK: Se... |
265 266 267 |
/* * slow path */ |
ffecfd1a7 block: optionally... |
268 |
__blk_queue_bounce(q, bio_orig, pool, must_bounce); |
831058dec [PATCH] BLOCK: Se... |
269 270 271 |
} EXPORT_SYMBOL(blk_queue_bounce); |