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> 253bce016aSChristoph Hellwig #include "blk.h" 26719c555fSJens Axboe 27719c555fSJens Axboe #define POOL_SIZE 64 28719c555fSJens Axboe #define ISA_POOL_SIZE 16 29719c555fSJens Axboe 30e0fc443aSBart Van Assche static struct bio_set *bounce_bio_set, *bounce_bio_split; 31719c555fSJens Axboe static mempool_t *page_pool, *isa_page_pool; 32719c555fSJens Axboe 33719c555fSJens Axboe #if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL) 34719c555fSJens Axboe static __init int init_emergency_pool(void) 35719c555fSJens Axboe { 36719c555fSJens Axboe #if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG) 37719c555fSJens Axboe if (max_pfn <= max_low_pfn) 38719c555fSJens Axboe return 0; 39719c555fSJens Axboe #endif 40719c555fSJens Axboe 41719c555fSJens Axboe page_pool = mempool_create_page_pool(POOL_SIZE, 0); 42719c555fSJens Axboe BUG_ON(!page_pool); 43b1de0d13SMitchel Humpherys pr_info("pool size: %d pages\n", POOL_SIZE); 44719c555fSJens Axboe 45a8821f3fSNeilBrown bounce_bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); 46a8821f3fSNeilBrown BUG_ON(!bounce_bio_set); 47a8821f3fSNeilBrown if (bioset_integrity_create(bounce_bio_set, BIO_POOL_SIZE)) 48a8821f3fSNeilBrown BUG_ON(1); 49a8821f3fSNeilBrown 50a8821f3fSNeilBrown bounce_bio_split = bioset_create(BIO_POOL_SIZE, 0, 0); 51a8821f3fSNeilBrown BUG_ON(!bounce_bio_split); 52a8821f3fSNeilBrown 53719c555fSJens Axboe return 0; 54719c555fSJens Axboe } 55719c555fSJens Axboe 56719c555fSJens Axboe __initcall(init_emergency_pool); 57719c555fSJens Axboe #endif 58719c555fSJens Axboe 59719c555fSJens Axboe #ifdef CONFIG_HIGHMEM 60719c555fSJens Axboe /* 61719c555fSJens Axboe * highmem version, map in to vec 62719c555fSJens Axboe */ 63719c555fSJens Axboe static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) 64719c555fSJens Axboe { 65719c555fSJens Axboe unsigned long flags; 66719c555fSJens Axboe unsigned char *vto; 67719c555fSJens Axboe 68719c555fSJens Axboe local_irq_save(flags); 69719c555fSJens Axboe vto = kmap_atomic(to->bv_page); 70719c555fSJens Axboe memcpy(vto + to->bv_offset, vfrom, to->bv_len); 71719c555fSJens Axboe kunmap_atomic(vto); 72719c555fSJens Axboe local_irq_restore(flags); 73719c555fSJens Axboe } 74719c555fSJens Axboe 75719c555fSJens Axboe #else /* CONFIG_HIGHMEM */ 76719c555fSJens Axboe 77719c555fSJens Axboe #define bounce_copy_vec(to, vfrom) \ 78719c555fSJens Axboe memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) 79719c555fSJens Axboe 80719c555fSJens Axboe #endif /* CONFIG_HIGHMEM */ 81719c555fSJens Axboe 82719c555fSJens Axboe /* 83719c555fSJens Axboe * allocate pages in the DMA region for the ISA pool 84719c555fSJens Axboe */ 85719c555fSJens Axboe static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) 86719c555fSJens Axboe { 87719c555fSJens Axboe return mempool_alloc_pages(gfp_mask | GFP_DMA, data); 88719c555fSJens Axboe } 89719c555fSJens Axboe 90719c555fSJens Axboe /* 91719c555fSJens Axboe * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA 92719c555fSJens Axboe * as the max address, so check if the pool has already been created. 93719c555fSJens Axboe */ 94719c555fSJens Axboe int init_emergency_isa_pool(void) 95719c555fSJens Axboe { 96719c555fSJens Axboe if (isa_page_pool) 97719c555fSJens Axboe return 0; 98719c555fSJens Axboe 99719c555fSJens Axboe isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, 100719c555fSJens Axboe mempool_free_pages, (void *) 0); 101719c555fSJens Axboe BUG_ON(!isa_page_pool); 102719c555fSJens Axboe 103b1de0d13SMitchel Humpherys pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE); 104719c555fSJens Axboe return 0; 105719c555fSJens Axboe } 106719c555fSJens Axboe 107719c555fSJens Axboe /* 108719c555fSJens Axboe * Simple bounce buffer support for highmem pages. Depending on the 109719c555fSJens Axboe * queue gfp mask set, *to may or may not be a highmem page. kmap it 110719c555fSJens Axboe * always, it will do the Right Thing 111719c555fSJens Axboe */ 112719c555fSJens Axboe static void copy_to_high_bio_irq(struct bio *to, struct bio *from) 113719c555fSJens Axboe { 114719c555fSJens Axboe unsigned char *vfrom; 115719c555fSJens Axboe struct bio_vec tovec, *fromvec = from->bi_io_vec; 116719c555fSJens Axboe struct bvec_iter iter; 117719c555fSJens Axboe 118719c555fSJens Axboe bio_for_each_segment(tovec, to, iter) { 119719c555fSJens Axboe if (tovec.bv_page != fromvec->bv_page) { 120719c555fSJens Axboe /* 121719c555fSJens Axboe * fromvec->bv_offset and fromvec->bv_len might have 122719c555fSJens Axboe * been modified by the block layer, so use the original 123719c555fSJens Axboe * copy, bounce_copy_vec already uses tovec->bv_len 124719c555fSJens Axboe */ 125719c555fSJens Axboe vfrom = page_address(fromvec->bv_page) + 126719c555fSJens Axboe tovec.bv_offset; 127719c555fSJens Axboe 128719c555fSJens Axboe bounce_copy_vec(&tovec, vfrom); 129719c555fSJens Axboe flush_dcache_page(tovec.bv_page); 130719c555fSJens Axboe } 131719c555fSJens Axboe 132719c555fSJens Axboe fromvec++; 133719c555fSJens Axboe } 134719c555fSJens Axboe } 135719c555fSJens Axboe 1364246a0b6SChristoph Hellwig static void bounce_end_io(struct bio *bio, mempool_t *pool) 137719c555fSJens Axboe { 138719c555fSJens Axboe struct bio *bio_orig = bio->bi_private; 139719c555fSJens Axboe struct bio_vec *bvec, *org_vec; 140719c555fSJens Axboe int i; 14199451879SMing Lei int start = bio_orig->bi_iter.bi_idx; 142719c555fSJens Axboe 143719c555fSJens Axboe /* 144719c555fSJens Axboe * free up bounce indirect pages used 145719c555fSJens Axboe */ 146719c555fSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 14799451879SMing Lei org_vec = bio_orig->bi_io_vec + i + start; 14899451879SMing Lei 149719c555fSJens Axboe if (bvec->bv_page == org_vec->bv_page) 150719c555fSJens Axboe continue; 151719c555fSJens Axboe 152719c555fSJens Axboe dec_zone_page_state(bvec->bv_page, NR_BOUNCE); 153719c555fSJens Axboe mempool_free(bvec->bv_page, pool); 154719c555fSJens Axboe } 155719c555fSJens Axboe 1564e4cbee9SChristoph Hellwig bio_orig->bi_status = bio->bi_status; 1574246a0b6SChristoph Hellwig bio_endio(bio_orig); 158719c555fSJens Axboe bio_put(bio); 159719c555fSJens Axboe } 160719c555fSJens Axboe 1614246a0b6SChristoph Hellwig static void bounce_end_io_write(struct bio *bio) 162719c555fSJens Axboe { 1634246a0b6SChristoph Hellwig bounce_end_io(bio, page_pool); 164719c555fSJens Axboe } 165719c555fSJens Axboe 1664246a0b6SChristoph Hellwig static void bounce_end_io_write_isa(struct bio *bio) 167719c555fSJens Axboe { 168719c555fSJens Axboe 1694246a0b6SChristoph Hellwig bounce_end_io(bio, isa_page_pool); 170719c555fSJens Axboe } 171719c555fSJens Axboe 1724246a0b6SChristoph Hellwig static void __bounce_end_io_read(struct bio *bio, mempool_t *pool) 173719c555fSJens Axboe { 174719c555fSJens Axboe struct bio *bio_orig = bio->bi_private; 175719c555fSJens Axboe 1764e4cbee9SChristoph Hellwig if (!bio->bi_status) 177719c555fSJens Axboe copy_to_high_bio_irq(bio_orig, bio); 178719c555fSJens Axboe 1794246a0b6SChristoph Hellwig bounce_end_io(bio, pool); 180719c555fSJens Axboe } 181719c555fSJens Axboe 1824246a0b6SChristoph Hellwig static void bounce_end_io_read(struct bio *bio) 183719c555fSJens Axboe { 1844246a0b6SChristoph Hellwig __bounce_end_io_read(bio, page_pool); 185719c555fSJens Axboe } 186719c555fSJens Axboe 1874246a0b6SChristoph Hellwig static void bounce_end_io_read_isa(struct bio *bio) 188719c555fSJens Axboe { 1894246a0b6SChristoph Hellwig __bounce_end_io_read(bio, isa_page_pool); 190719c555fSJens Axboe } 191719c555fSJens Axboe 192719c555fSJens Axboe static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, 193a3ad0a9dSJan Kara mempool_t *pool) 194719c555fSJens Axboe { 195719c555fSJens Axboe struct bio *bio; 196719c555fSJens Axboe int rw = bio_data_dir(*bio_orig); 197719c555fSJens Axboe struct bio_vec *to, from; 198719c555fSJens Axboe struct bvec_iter iter; 199a8821f3fSNeilBrown unsigned i = 0; 200a8821f3fSNeilBrown bool bounce = false; 201a8821f3fSNeilBrown int sectors = 0; 202719c555fSJens Axboe 203a8821f3fSNeilBrown bio_for_each_segment(from, *bio_orig, iter) { 204a8821f3fSNeilBrown if (i++ < BIO_MAX_PAGES) 205a8821f3fSNeilBrown sectors += from.bv_len >> 9; 206719c555fSJens Axboe if (page_to_pfn(from.bv_page) > queue_bounce_pfn(q)) 207a8821f3fSNeilBrown bounce = true; 208a8821f3fSNeilBrown } 209a8821f3fSNeilBrown if (!bounce) 210719c555fSJens Axboe return; 211a8821f3fSNeilBrown 212a8821f3fSNeilBrown if (sectors < bio_sectors(*bio_orig)) { 213a8821f3fSNeilBrown bio = bio_split(*bio_orig, sectors, GFP_NOIO, bounce_bio_split); 214a8821f3fSNeilBrown bio_chain(bio, *bio_orig); 215a8821f3fSNeilBrown generic_make_request(*bio_orig); 216a8821f3fSNeilBrown *bio_orig = bio; 217a8821f3fSNeilBrown } 218a8821f3fSNeilBrown bio = bio_clone_bioset(*bio_orig, GFP_NOIO, bounce_bio_set); 219719c555fSJens Axboe 220719c555fSJens Axboe bio_for_each_segment_all(to, bio, i) { 221719c555fSJens Axboe struct page *page = to->bv_page; 222719c555fSJens Axboe 223a3ad0a9dSJan Kara if (page_to_pfn(page) <= queue_bounce_pfn(q)) 224719c555fSJens Axboe continue; 225719c555fSJens Axboe 226719c555fSJens Axboe to->bv_page = mempool_alloc(pool, q->bounce_gfp); 227393a3397SWang YanQing inc_zone_page_state(to->bv_page, NR_BOUNCE); 228719c555fSJens Axboe 229719c555fSJens Axboe if (rw == WRITE) { 230719c555fSJens Axboe char *vto, *vfrom; 231719c555fSJens Axboe 232719c555fSJens Axboe flush_dcache_page(page); 233719c555fSJens Axboe 234719c555fSJens Axboe vto = page_address(to->bv_page) + to->bv_offset; 235719c555fSJens Axboe vfrom = kmap_atomic(page) + to->bv_offset; 236719c555fSJens Axboe memcpy(vto, vfrom, to->bv_len); 237719c555fSJens Axboe kunmap_atomic(vfrom); 238719c555fSJens Axboe } 239719c555fSJens Axboe } 240719c555fSJens Axboe 241719c555fSJens Axboe trace_block_bio_bounce(q, *bio_orig); 242719c555fSJens Axboe 243719c555fSJens Axboe bio->bi_flags |= (1 << BIO_BOUNCED); 244719c555fSJens Axboe 245719c555fSJens Axboe if (pool == page_pool) { 246719c555fSJens Axboe bio->bi_end_io = bounce_end_io_write; 247719c555fSJens Axboe if (rw == READ) 248719c555fSJens Axboe bio->bi_end_io = bounce_end_io_read; 249719c555fSJens Axboe } else { 250719c555fSJens Axboe bio->bi_end_io = bounce_end_io_write_isa; 251719c555fSJens Axboe if (rw == READ) 252719c555fSJens Axboe bio->bi_end_io = bounce_end_io_read_isa; 253719c555fSJens Axboe } 254719c555fSJens Axboe 255719c555fSJens Axboe bio->bi_private = *bio_orig; 256719c555fSJens Axboe *bio_orig = bio; 257719c555fSJens Axboe } 258719c555fSJens Axboe 259719c555fSJens Axboe void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) 260719c555fSJens Axboe { 261719c555fSJens Axboe mempool_t *pool; 262719c555fSJens Axboe 263719c555fSJens Axboe /* 264719c555fSJens Axboe * Data-less bio, nothing to bounce 265719c555fSJens Axboe */ 266719c555fSJens Axboe if (!bio_has_data(*bio_orig)) 267719c555fSJens Axboe return; 268719c555fSJens Axboe 269719c555fSJens Axboe /* 270719c555fSJens Axboe * for non-isa bounce case, just check if the bounce pfn is equal 271719c555fSJens Axboe * to or bigger than the highest pfn in the system -- in that case, 272719c555fSJens Axboe * don't waste time iterating over bio segments 273719c555fSJens Axboe */ 274719c555fSJens Axboe if (!(q->bounce_gfp & GFP_DMA)) { 275a3ad0a9dSJan Kara if (queue_bounce_pfn(q) >= blk_max_pfn) 276719c555fSJens Axboe return; 277719c555fSJens Axboe pool = page_pool; 278719c555fSJens Axboe } else { 279719c555fSJens Axboe BUG_ON(!isa_page_pool); 280719c555fSJens Axboe pool = isa_page_pool; 281719c555fSJens Axboe } 282719c555fSJens Axboe 283719c555fSJens Axboe /* 284719c555fSJens Axboe * slow path 285719c555fSJens Axboe */ 286a3ad0a9dSJan Kara __blk_queue_bounce(q, bio_orig, pool); 287719c555fSJens Axboe } 288