1719c555fSJens Axboe /* bounce buffer handling for block devices 2719c555fSJens Axboe * 3719c555fSJens Axboe * - Split from highmem.c 4719c555fSJens Axboe */ 5719c555fSJens Axboe 6b1de0d13SMitchel Humpherys #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 7b1de0d13SMitchel Humpherys 8719c555fSJens Axboe #include <linux/mm.h> 9719c555fSJens Axboe #include <linux/export.h> 10719c555fSJens Axboe #include <linux/swap.h> 11719c555fSJens Axboe #include <linux/gfp.h> 12719c555fSJens Axboe #include <linux/bio.h> 13719c555fSJens Axboe #include <linux/pagemap.h> 14719c555fSJens Axboe #include <linux/mempool.h> 15719c555fSJens Axboe #include <linux/blkdev.h> 1666114cadSTejun Heo #include <linux/backing-dev.h> 17719c555fSJens Axboe #include <linux/init.h> 18719c555fSJens Axboe #include <linux/hash.h> 19719c555fSJens Axboe #include <linux/highmem.h> 20719c555fSJens Axboe #include <linux/bootmem.h> 21b1de0d13SMitchel Humpherys #include <linux/printk.h> 22719c555fSJens Axboe #include <asm/tlbflush.h> 23719c555fSJens Axboe 24719c555fSJens Axboe #include <trace/events/block.h> 25719c555fSJens Axboe 26719c555fSJens Axboe #define POOL_SIZE 64 27719c555fSJens Axboe #define ISA_POOL_SIZE 16 28719c555fSJens Axboe 29e0fc443aSBart Van Assche static struct bio_set *bounce_bio_set, *bounce_bio_split; 30719c555fSJens Axboe static mempool_t *page_pool, *isa_page_pool; 31719c555fSJens Axboe 32719c555fSJens Axboe #if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL) 33719c555fSJens Axboe static __init int init_emergency_pool(void) 34719c555fSJens Axboe { 35719c555fSJens Axboe #if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG) 36719c555fSJens Axboe if (max_pfn <= max_low_pfn) 37719c555fSJens Axboe return 0; 38719c555fSJens Axboe #endif 39719c555fSJens Axboe 40719c555fSJens Axboe page_pool = mempool_create_page_pool(POOL_SIZE, 0); 41719c555fSJens Axboe BUG_ON(!page_pool); 42b1de0d13SMitchel Humpherys pr_info("pool size: %d pages\n", POOL_SIZE); 43719c555fSJens Axboe 44a8821f3fSNeilBrown bounce_bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); 45a8821f3fSNeilBrown BUG_ON(!bounce_bio_set); 46a8821f3fSNeilBrown if (bioset_integrity_create(bounce_bio_set, BIO_POOL_SIZE)) 47a8821f3fSNeilBrown BUG_ON(1); 48a8821f3fSNeilBrown 49a8821f3fSNeilBrown bounce_bio_split = bioset_create(BIO_POOL_SIZE, 0, 0); 50a8821f3fSNeilBrown BUG_ON(!bounce_bio_split); 51a8821f3fSNeilBrown 52719c555fSJens Axboe return 0; 53719c555fSJens Axboe } 54719c555fSJens Axboe 55719c555fSJens Axboe __initcall(init_emergency_pool); 56719c555fSJens Axboe #endif 57719c555fSJens Axboe 58719c555fSJens Axboe #ifdef CONFIG_HIGHMEM 59719c555fSJens Axboe /* 60719c555fSJens Axboe * highmem version, map in to vec 61719c555fSJens Axboe */ 62719c555fSJens Axboe static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) 63719c555fSJens Axboe { 64719c555fSJens Axboe unsigned long flags; 65719c555fSJens Axboe unsigned char *vto; 66719c555fSJens Axboe 67719c555fSJens Axboe local_irq_save(flags); 68719c555fSJens Axboe vto = kmap_atomic(to->bv_page); 69719c555fSJens Axboe memcpy(vto + to->bv_offset, vfrom, to->bv_len); 70719c555fSJens Axboe kunmap_atomic(vto); 71719c555fSJens Axboe local_irq_restore(flags); 72719c555fSJens Axboe } 73719c555fSJens Axboe 74719c555fSJens Axboe #else /* CONFIG_HIGHMEM */ 75719c555fSJens Axboe 76719c555fSJens Axboe #define bounce_copy_vec(to, vfrom) \ 77719c555fSJens Axboe memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) 78719c555fSJens Axboe 79719c555fSJens Axboe #endif /* CONFIG_HIGHMEM */ 80719c555fSJens Axboe 81719c555fSJens Axboe /* 82719c555fSJens Axboe * allocate pages in the DMA region for the ISA pool 83719c555fSJens Axboe */ 84719c555fSJens Axboe static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) 85719c555fSJens Axboe { 86719c555fSJens Axboe return mempool_alloc_pages(gfp_mask | GFP_DMA, data); 87719c555fSJens Axboe } 88719c555fSJens Axboe 89719c555fSJens Axboe /* 90719c555fSJens Axboe * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA 91719c555fSJens Axboe * as the max address, so check if the pool has already been created. 92719c555fSJens Axboe */ 93719c555fSJens Axboe int init_emergency_isa_pool(void) 94719c555fSJens Axboe { 95719c555fSJens Axboe if (isa_page_pool) 96719c555fSJens Axboe return 0; 97719c555fSJens Axboe 98719c555fSJens Axboe isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, 99719c555fSJens Axboe mempool_free_pages, (void *) 0); 100719c555fSJens Axboe BUG_ON(!isa_page_pool); 101719c555fSJens Axboe 102b1de0d13SMitchel Humpherys pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE); 103719c555fSJens Axboe return 0; 104719c555fSJens Axboe } 105719c555fSJens Axboe 106719c555fSJens Axboe /* 107719c555fSJens Axboe * Simple bounce buffer support for highmem pages. Depending on the 108719c555fSJens Axboe * queue gfp mask set, *to may or may not be a highmem page. kmap it 109719c555fSJens Axboe * always, it will do the Right Thing 110719c555fSJens Axboe */ 111719c555fSJens Axboe static void copy_to_high_bio_irq(struct bio *to, struct bio *from) 112719c555fSJens Axboe { 113719c555fSJens Axboe unsigned char *vfrom; 114719c555fSJens Axboe struct bio_vec tovec, *fromvec = from->bi_io_vec; 115719c555fSJens Axboe struct bvec_iter iter; 116719c555fSJens Axboe 117719c555fSJens Axboe bio_for_each_segment(tovec, to, iter) { 118719c555fSJens Axboe if (tovec.bv_page != fromvec->bv_page) { 119719c555fSJens Axboe /* 120719c555fSJens Axboe * fromvec->bv_offset and fromvec->bv_len might have 121719c555fSJens Axboe * been modified by the block layer, so use the original 122719c555fSJens Axboe * copy, bounce_copy_vec already uses tovec->bv_len 123719c555fSJens Axboe */ 124719c555fSJens Axboe vfrom = page_address(fromvec->bv_page) + 125719c555fSJens Axboe tovec.bv_offset; 126719c555fSJens Axboe 127719c555fSJens Axboe bounce_copy_vec(&tovec, vfrom); 128719c555fSJens Axboe flush_dcache_page(tovec.bv_page); 129719c555fSJens Axboe } 130719c555fSJens Axboe 131719c555fSJens Axboe fromvec++; 132719c555fSJens Axboe } 133719c555fSJens Axboe } 134719c555fSJens Axboe 1354246a0b6SChristoph Hellwig static void bounce_end_io(struct bio *bio, mempool_t *pool) 136719c555fSJens Axboe { 137719c555fSJens Axboe struct bio *bio_orig = bio->bi_private; 138719c555fSJens Axboe struct bio_vec *bvec, *org_vec; 139719c555fSJens Axboe int i; 14099451879SMing Lei int start = bio_orig->bi_iter.bi_idx; 141719c555fSJens Axboe 142719c555fSJens Axboe /* 143719c555fSJens Axboe * free up bounce indirect pages used 144719c555fSJens Axboe */ 145719c555fSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 14699451879SMing Lei org_vec = bio_orig->bi_io_vec + i + start; 14799451879SMing Lei 148719c555fSJens Axboe if (bvec->bv_page == org_vec->bv_page) 149719c555fSJens Axboe continue; 150719c555fSJens Axboe 151719c555fSJens Axboe dec_zone_page_state(bvec->bv_page, NR_BOUNCE); 152719c555fSJens Axboe mempool_free(bvec->bv_page, pool); 153719c555fSJens Axboe } 154719c555fSJens Axboe 1554e4cbee9SChristoph Hellwig bio_orig->bi_status = bio->bi_status; 1564246a0b6SChristoph Hellwig bio_endio(bio_orig); 157719c555fSJens Axboe bio_put(bio); 158719c555fSJens Axboe } 159719c555fSJens Axboe 1604246a0b6SChristoph Hellwig static void bounce_end_io_write(struct bio *bio) 161719c555fSJens Axboe { 1624246a0b6SChristoph Hellwig bounce_end_io(bio, page_pool); 163719c555fSJens Axboe } 164719c555fSJens Axboe 1654246a0b6SChristoph Hellwig static void bounce_end_io_write_isa(struct bio *bio) 166719c555fSJens Axboe { 167719c555fSJens Axboe 1684246a0b6SChristoph Hellwig bounce_end_io(bio, isa_page_pool); 169719c555fSJens Axboe } 170719c555fSJens Axboe 1714246a0b6SChristoph Hellwig static void __bounce_end_io_read(struct bio *bio, mempool_t *pool) 172719c555fSJens Axboe { 173719c555fSJens Axboe struct bio *bio_orig = bio->bi_private; 174719c555fSJens Axboe 1754e4cbee9SChristoph Hellwig if (!bio->bi_status) 176719c555fSJens Axboe copy_to_high_bio_irq(bio_orig, bio); 177719c555fSJens Axboe 1784246a0b6SChristoph Hellwig bounce_end_io(bio, pool); 179719c555fSJens Axboe } 180719c555fSJens Axboe 1814246a0b6SChristoph Hellwig static void bounce_end_io_read(struct bio *bio) 182719c555fSJens Axboe { 1834246a0b6SChristoph Hellwig __bounce_end_io_read(bio, page_pool); 184719c555fSJens Axboe } 185719c555fSJens Axboe 1864246a0b6SChristoph Hellwig static void bounce_end_io_read_isa(struct bio *bio) 187719c555fSJens Axboe { 1884246a0b6SChristoph Hellwig __bounce_end_io_read(bio, isa_page_pool); 189719c555fSJens Axboe } 190719c555fSJens Axboe 191719c555fSJens Axboe static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, 192a3ad0a9dSJan Kara mempool_t *pool) 193719c555fSJens Axboe { 194719c555fSJens Axboe struct bio *bio; 195719c555fSJens Axboe int rw = bio_data_dir(*bio_orig); 196719c555fSJens Axboe struct bio_vec *to, from; 197719c555fSJens Axboe struct bvec_iter iter; 198a8821f3fSNeilBrown unsigned i = 0; 199a8821f3fSNeilBrown bool bounce = false; 200a8821f3fSNeilBrown int sectors = 0; 201719c555fSJens Axboe 202a8821f3fSNeilBrown bio_for_each_segment(from, *bio_orig, iter) { 203a8821f3fSNeilBrown if (i++ < BIO_MAX_PAGES) 204a8821f3fSNeilBrown sectors += from.bv_len >> 9; 205719c555fSJens Axboe if (page_to_pfn(from.bv_page) > queue_bounce_pfn(q)) 206a8821f3fSNeilBrown bounce = true; 207a8821f3fSNeilBrown } 208a8821f3fSNeilBrown if (!bounce) 209719c555fSJens Axboe return; 210a8821f3fSNeilBrown 211a8821f3fSNeilBrown if (sectors < bio_sectors(*bio_orig)) { 212a8821f3fSNeilBrown bio = bio_split(*bio_orig, sectors, GFP_NOIO, bounce_bio_split); 213a8821f3fSNeilBrown bio_chain(bio, *bio_orig); 214a8821f3fSNeilBrown generic_make_request(*bio_orig); 215a8821f3fSNeilBrown *bio_orig = bio; 216a8821f3fSNeilBrown } 217a8821f3fSNeilBrown bio = bio_clone_bioset(*bio_orig, GFP_NOIO, bounce_bio_set); 218719c555fSJens Axboe 219719c555fSJens Axboe bio_for_each_segment_all(to, bio, i) { 220719c555fSJens Axboe struct page *page = to->bv_page; 221719c555fSJens Axboe 222a3ad0a9dSJan Kara if (page_to_pfn(page) <= queue_bounce_pfn(q)) 223719c555fSJens Axboe continue; 224719c555fSJens Axboe 225719c555fSJens Axboe to->bv_page = mempool_alloc(pool, q->bounce_gfp); 226393a3397SWang YanQing inc_zone_page_state(to->bv_page, NR_BOUNCE); 227719c555fSJens Axboe 228719c555fSJens Axboe if (rw == WRITE) { 229719c555fSJens Axboe char *vto, *vfrom; 230719c555fSJens Axboe 231719c555fSJens Axboe flush_dcache_page(page); 232719c555fSJens Axboe 233719c555fSJens Axboe vto = page_address(to->bv_page) + to->bv_offset; 234719c555fSJens Axboe vfrom = kmap_atomic(page) + to->bv_offset; 235719c555fSJens Axboe memcpy(vto, vfrom, to->bv_len); 236719c555fSJens Axboe kunmap_atomic(vfrom); 237719c555fSJens Axboe } 238719c555fSJens Axboe } 239719c555fSJens Axboe 240719c555fSJens Axboe trace_block_bio_bounce(q, *bio_orig); 241719c555fSJens Axboe 242719c555fSJens Axboe bio->bi_flags |= (1 << BIO_BOUNCED); 243719c555fSJens Axboe 244719c555fSJens Axboe if (pool == page_pool) { 245719c555fSJens Axboe bio->bi_end_io = bounce_end_io_write; 246719c555fSJens Axboe if (rw == READ) 247719c555fSJens Axboe bio->bi_end_io = bounce_end_io_read; 248719c555fSJens Axboe } else { 249719c555fSJens Axboe bio->bi_end_io = bounce_end_io_write_isa; 250719c555fSJens Axboe if (rw == READ) 251719c555fSJens Axboe bio->bi_end_io = bounce_end_io_read_isa; 252719c555fSJens Axboe } 253719c555fSJens Axboe 254719c555fSJens Axboe bio->bi_private = *bio_orig; 255719c555fSJens Axboe *bio_orig = bio; 256719c555fSJens Axboe } 257719c555fSJens Axboe 258719c555fSJens Axboe void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) 259719c555fSJens Axboe { 260719c555fSJens Axboe mempool_t *pool; 261719c555fSJens Axboe 262719c555fSJens Axboe /* 263719c555fSJens Axboe * Data-less bio, nothing to bounce 264719c555fSJens Axboe */ 265719c555fSJens Axboe if (!bio_has_data(*bio_orig)) 266719c555fSJens Axboe return; 267719c555fSJens Axboe 268719c555fSJens Axboe /* 269719c555fSJens Axboe * for non-isa bounce case, just check if the bounce pfn is equal 270719c555fSJens Axboe * to or bigger than the highest pfn in the system -- in that case, 271719c555fSJens Axboe * don't waste time iterating over bio segments 272719c555fSJens Axboe */ 273719c555fSJens Axboe if (!(q->bounce_gfp & GFP_DMA)) { 274a3ad0a9dSJan Kara if (queue_bounce_pfn(q) >= blk_max_pfn) 275719c555fSJens Axboe return; 276719c555fSJens Axboe pool = page_pool; 277719c555fSJens Axboe } else { 278719c555fSJens Axboe BUG_ON(!isa_page_pool); 279719c555fSJens Axboe pool = isa_page_pool; 280719c555fSJens Axboe } 281719c555fSJens Axboe 282719c555fSJens Axboe /* 283719c555fSJens Axboe * slow path 284719c555fSJens Axboe */ 285a3ad0a9dSJan Kara __blk_queue_bounce(q, bio_orig, pool); 286719c555fSJens Axboe } 287719c555fSJens Axboe 288719c555fSJens Axboe EXPORT_SYMBOL(blk_queue_bounce); 289