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 29719c555fSJens Axboe static mempool_t *page_pool, *isa_page_pool; 30719c555fSJens Axboe 31719c555fSJens Axboe #if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL) 32719c555fSJens Axboe static __init int init_emergency_pool(void) 33719c555fSJens Axboe { 34719c555fSJens Axboe #if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG) 35719c555fSJens Axboe if (max_pfn <= max_low_pfn) 36719c555fSJens Axboe return 0; 37719c555fSJens Axboe #endif 38719c555fSJens Axboe 39719c555fSJens Axboe page_pool = mempool_create_page_pool(POOL_SIZE, 0); 40719c555fSJens Axboe BUG_ON(!page_pool); 41b1de0d13SMitchel Humpherys pr_info("pool size: %d pages\n", POOL_SIZE); 42719c555fSJens Axboe 43719c555fSJens Axboe return 0; 44719c555fSJens Axboe } 45719c555fSJens Axboe 46719c555fSJens Axboe __initcall(init_emergency_pool); 47719c555fSJens Axboe #endif 48719c555fSJens Axboe 49719c555fSJens Axboe #ifdef CONFIG_HIGHMEM 50719c555fSJens Axboe /* 51719c555fSJens Axboe * highmem version, map in to vec 52719c555fSJens Axboe */ 53719c555fSJens Axboe static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) 54719c555fSJens Axboe { 55719c555fSJens Axboe unsigned long flags; 56719c555fSJens Axboe unsigned char *vto; 57719c555fSJens Axboe 58719c555fSJens Axboe local_irq_save(flags); 59719c555fSJens Axboe vto = kmap_atomic(to->bv_page); 60719c555fSJens Axboe memcpy(vto + to->bv_offset, vfrom, to->bv_len); 61719c555fSJens Axboe kunmap_atomic(vto); 62719c555fSJens Axboe local_irq_restore(flags); 63719c555fSJens Axboe } 64719c555fSJens Axboe 65719c555fSJens Axboe #else /* CONFIG_HIGHMEM */ 66719c555fSJens Axboe 67719c555fSJens Axboe #define bounce_copy_vec(to, vfrom) \ 68719c555fSJens Axboe memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) 69719c555fSJens Axboe 70719c555fSJens Axboe #endif /* CONFIG_HIGHMEM */ 71719c555fSJens Axboe 72719c555fSJens Axboe /* 73719c555fSJens Axboe * allocate pages in the DMA region for the ISA pool 74719c555fSJens Axboe */ 75719c555fSJens Axboe static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) 76719c555fSJens Axboe { 77719c555fSJens Axboe return mempool_alloc_pages(gfp_mask | GFP_DMA, data); 78719c555fSJens Axboe } 79719c555fSJens Axboe 80719c555fSJens Axboe /* 81719c555fSJens Axboe * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA 82719c555fSJens Axboe * as the max address, so check if the pool has already been created. 83719c555fSJens Axboe */ 84719c555fSJens Axboe int init_emergency_isa_pool(void) 85719c555fSJens Axboe { 86719c555fSJens Axboe if (isa_page_pool) 87719c555fSJens Axboe return 0; 88719c555fSJens Axboe 89719c555fSJens Axboe isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, 90719c555fSJens Axboe mempool_free_pages, (void *) 0); 91719c555fSJens Axboe BUG_ON(!isa_page_pool); 92719c555fSJens Axboe 93b1de0d13SMitchel Humpherys pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE); 94719c555fSJens Axboe return 0; 95719c555fSJens Axboe } 96719c555fSJens Axboe 97719c555fSJens Axboe /* 98719c555fSJens Axboe * Simple bounce buffer support for highmem pages. Depending on the 99719c555fSJens Axboe * queue gfp mask set, *to may or may not be a highmem page. kmap it 100719c555fSJens Axboe * always, it will do the Right Thing 101719c555fSJens Axboe */ 102719c555fSJens Axboe static void copy_to_high_bio_irq(struct bio *to, struct bio *from) 103719c555fSJens Axboe { 104719c555fSJens Axboe unsigned char *vfrom; 105719c555fSJens Axboe struct bio_vec tovec, *fromvec = from->bi_io_vec; 106719c555fSJens Axboe struct bvec_iter iter; 107719c555fSJens Axboe 108719c555fSJens Axboe bio_for_each_segment(tovec, to, iter) { 109719c555fSJens Axboe if (tovec.bv_page != fromvec->bv_page) { 110719c555fSJens Axboe /* 111719c555fSJens Axboe * fromvec->bv_offset and fromvec->bv_len might have 112719c555fSJens Axboe * been modified by the block layer, so use the original 113719c555fSJens Axboe * copy, bounce_copy_vec already uses tovec->bv_len 114719c555fSJens Axboe */ 115719c555fSJens Axboe vfrom = page_address(fromvec->bv_page) + 116719c555fSJens Axboe tovec.bv_offset; 117719c555fSJens Axboe 118719c555fSJens Axboe bounce_copy_vec(&tovec, vfrom); 119719c555fSJens Axboe flush_dcache_page(tovec.bv_page); 120719c555fSJens Axboe } 121719c555fSJens Axboe 122719c555fSJens Axboe fromvec++; 123719c555fSJens Axboe } 124719c555fSJens Axboe } 125719c555fSJens Axboe 126719c555fSJens Axboe static void bounce_end_io(struct bio *bio, mempool_t *pool, int err) 127719c555fSJens Axboe { 128719c555fSJens Axboe struct bio *bio_orig = bio->bi_private; 129719c555fSJens Axboe struct bio_vec *bvec, *org_vec; 130719c555fSJens Axboe int i; 131719c555fSJens Axboe 132719c555fSJens Axboe /* 133719c555fSJens Axboe * free up bounce indirect pages used 134719c555fSJens Axboe */ 135719c555fSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 136719c555fSJens Axboe org_vec = bio_orig->bi_io_vec + i; 137719c555fSJens Axboe if (bvec->bv_page == org_vec->bv_page) 138719c555fSJens Axboe continue; 139719c555fSJens Axboe 140719c555fSJens Axboe dec_zone_page_state(bvec->bv_page, NR_BOUNCE); 141719c555fSJens Axboe mempool_free(bvec->bv_page, pool); 142719c555fSJens Axboe } 143719c555fSJens Axboe 144719c555fSJens Axboe bio_endio(bio_orig, err); 145719c555fSJens Axboe bio_put(bio); 146719c555fSJens Axboe } 147719c555fSJens Axboe 148719c555fSJens Axboe static void bounce_end_io_write(struct bio *bio, int err) 149719c555fSJens Axboe { 150719c555fSJens Axboe bounce_end_io(bio, page_pool, err); 151719c555fSJens Axboe } 152719c555fSJens Axboe 153719c555fSJens Axboe static void bounce_end_io_write_isa(struct bio *bio, int err) 154719c555fSJens Axboe { 155719c555fSJens Axboe 156719c555fSJens Axboe bounce_end_io(bio, isa_page_pool, err); 157719c555fSJens Axboe } 158719c555fSJens Axboe 159719c555fSJens Axboe static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err) 160719c555fSJens Axboe { 161719c555fSJens Axboe struct bio *bio_orig = bio->bi_private; 162719c555fSJens Axboe 163719c555fSJens Axboe if (test_bit(BIO_UPTODATE, &bio->bi_flags)) 164719c555fSJens Axboe copy_to_high_bio_irq(bio_orig, bio); 165719c555fSJens Axboe 166719c555fSJens Axboe bounce_end_io(bio, pool, err); 167719c555fSJens Axboe } 168719c555fSJens Axboe 169719c555fSJens Axboe static void bounce_end_io_read(struct bio *bio, int err) 170719c555fSJens Axboe { 171719c555fSJens Axboe __bounce_end_io_read(bio, page_pool, err); 172719c555fSJens Axboe } 173719c555fSJens Axboe 174719c555fSJens Axboe static void bounce_end_io_read_isa(struct bio *bio, int err) 175719c555fSJens Axboe { 176719c555fSJens Axboe __bounce_end_io_read(bio, isa_page_pool, err); 177719c555fSJens Axboe } 178719c555fSJens Axboe 179719c555fSJens Axboe static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, 180a3ad0a9dSJan Kara mempool_t *pool) 181719c555fSJens Axboe { 182719c555fSJens Axboe struct bio *bio; 183719c555fSJens Axboe int rw = bio_data_dir(*bio_orig); 184719c555fSJens Axboe struct bio_vec *to, from; 185719c555fSJens Axboe struct bvec_iter iter; 186719c555fSJens Axboe unsigned i; 187719c555fSJens Axboe 188719c555fSJens Axboe bio_for_each_segment(from, *bio_orig, iter) 189719c555fSJens Axboe if (page_to_pfn(from.bv_page) > queue_bounce_pfn(q)) 190719c555fSJens Axboe goto bounce; 191719c555fSJens Axboe 192719c555fSJens Axboe return; 193719c555fSJens Axboe bounce: 194719c555fSJens Axboe bio = bio_clone_bioset(*bio_orig, GFP_NOIO, fs_bio_set); 195719c555fSJens Axboe 196719c555fSJens Axboe bio_for_each_segment_all(to, bio, i) { 197719c555fSJens Axboe struct page *page = to->bv_page; 198719c555fSJens Axboe 199a3ad0a9dSJan Kara if (page_to_pfn(page) <= queue_bounce_pfn(q)) 200719c555fSJens Axboe continue; 201719c555fSJens Axboe 202719c555fSJens Axboe to->bv_page = mempool_alloc(pool, q->bounce_gfp); 203393a3397SWang YanQing inc_zone_page_state(to->bv_page, NR_BOUNCE); 204719c555fSJens Axboe 205719c555fSJens Axboe if (rw == WRITE) { 206719c555fSJens Axboe char *vto, *vfrom; 207719c555fSJens Axboe 208719c555fSJens Axboe flush_dcache_page(page); 209719c555fSJens Axboe 210719c555fSJens Axboe vto = page_address(to->bv_page) + to->bv_offset; 211719c555fSJens Axboe vfrom = kmap_atomic(page) + to->bv_offset; 212719c555fSJens Axboe memcpy(vto, vfrom, to->bv_len); 213719c555fSJens Axboe kunmap_atomic(vfrom); 214719c555fSJens Axboe } 215719c555fSJens Axboe } 216719c555fSJens Axboe 217719c555fSJens Axboe trace_block_bio_bounce(q, *bio_orig); 218719c555fSJens Axboe 219719c555fSJens Axboe bio->bi_flags |= (1 << BIO_BOUNCED); 220719c555fSJens Axboe 221719c555fSJens Axboe if (pool == page_pool) { 222719c555fSJens Axboe bio->bi_end_io = bounce_end_io_write; 223719c555fSJens Axboe if (rw == READ) 224719c555fSJens Axboe bio->bi_end_io = bounce_end_io_read; 225719c555fSJens Axboe } else { 226719c555fSJens Axboe bio->bi_end_io = bounce_end_io_write_isa; 227719c555fSJens Axboe if (rw == READ) 228719c555fSJens Axboe bio->bi_end_io = bounce_end_io_read_isa; 229719c555fSJens Axboe } 230719c555fSJens Axboe 231719c555fSJens Axboe bio->bi_private = *bio_orig; 232719c555fSJens Axboe *bio_orig = bio; 233719c555fSJens Axboe } 234719c555fSJens Axboe 235719c555fSJens Axboe void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) 236719c555fSJens Axboe { 237719c555fSJens Axboe mempool_t *pool; 238719c555fSJens Axboe 239719c555fSJens Axboe /* 240719c555fSJens Axboe * Data-less bio, nothing to bounce 241719c555fSJens Axboe */ 242719c555fSJens Axboe if (!bio_has_data(*bio_orig)) 243719c555fSJens Axboe return; 244719c555fSJens Axboe 245719c555fSJens Axboe /* 246719c555fSJens Axboe * for non-isa bounce case, just check if the bounce pfn is equal 247719c555fSJens Axboe * to or bigger than the highest pfn in the system -- in that case, 248719c555fSJens Axboe * don't waste time iterating over bio segments 249719c555fSJens Axboe */ 250719c555fSJens Axboe if (!(q->bounce_gfp & GFP_DMA)) { 251a3ad0a9dSJan Kara if (queue_bounce_pfn(q) >= blk_max_pfn) 252719c555fSJens Axboe return; 253719c555fSJens Axboe pool = page_pool; 254719c555fSJens Axboe } else { 255719c555fSJens Axboe BUG_ON(!isa_page_pool); 256719c555fSJens Axboe pool = isa_page_pool; 257719c555fSJens Axboe } 258719c555fSJens Axboe 259719c555fSJens Axboe /* 260719c555fSJens Axboe * slow path 261719c555fSJens Axboe */ 262a3ad0a9dSJan Kara __blk_queue_bounce(q, bio_orig, pool); 263719c555fSJens Axboe } 264719c555fSJens Axboe 265719c555fSJens Axboe EXPORT_SYMBOL(blk_queue_bounce); 266