diff options
Diffstat (limited to 'kernel/drivers/lightnvm/rrpc.c')
| -rw-r--r-- | kernel/drivers/lightnvm/rrpc.c | 1371 |
1 files changed, 1371 insertions, 0 deletions
diff --git a/kernel/drivers/lightnvm/rrpc.c b/kernel/drivers/lightnvm/rrpc.c new file mode 100644 index 000000000..134e4faba --- /dev/null +++ b/kernel/drivers/lightnvm/rrpc.c @@ -0,0 +1,1371 @@ +/* + * Copyright (C) 2015 IT University of Copenhagen + * Initial release: Matias Bjorling <m@bjorling.me> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs. + */ + +#include "rrpc.h" + +static struct kmem_cache *rrpc_gcb_cache, *rrpc_rq_cache; +static DECLARE_RWSEM(rrpc_lock); + +static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio, + struct nvm_rq *rqd, unsigned long flags); + +#define rrpc_for_each_lun(rrpc, rlun, i) \ + for ((i) = 0, rlun = &(rrpc)->luns[0]; \ + (i) < (rrpc)->nr_luns; (i)++, rlun = &(rrpc)->luns[(i)]) + +static void rrpc_page_invalidate(struct rrpc *rrpc, struct rrpc_addr *a) +{ + struct rrpc_block *rblk = a->rblk; + unsigned int pg_offset; + + lockdep_assert_held(&rrpc->rev_lock); + + if (a->addr == ADDR_EMPTY || !rblk) + return; + + spin_lock(&rblk->lock); + + div_u64_rem(a->addr, rrpc->dev->pgs_per_blk, &pg_offset); + WARN_ON(test_and_set_bit(pg_offset, rblk->invalid_pages)); + rblk->nr_invalid_pages++; + + spin_unlock(&rblk->lock); + + rrpc->rev_trans_map[a->addr - rrpc->poffset].addr = ADDR_EMPTY; +} + +static void rrpc_invalidate_range(struct rrpc *rrpc, sector_t slba, + unsigned len) +{ + sector_t i; + + spin_lock(&rrpc->rev_lock); + for (i = slba; i < slba + len; i++) { + struct rrpc_addr *gp = &rrpc->trans_map[i]; + + rrpc_page_invalidate(rrpc, gp); + gp->rblk = NULL; + } + spin_unlock(&rrpc->rev_lock); +} + +static struct nvm_rq *rrpc_inflight_laddr_acquire(struct rrpc *rrpc, + sector_t laddr, unsigned int pages) +{ + struct nvm_rq *rqd; + struct rrpc_inflight_rq *inf; + + rqd = mempool_alloc(rrpc->rq_pool, GFP_ATOMIC); + if (!rqd) + return ERR_PTR(-ENOMEM); + + inf = rrpc_get_inflight_rq(rqd); + if (rrpc_lock_laddr(rrpc, laddr, pages, inf)) { + mempool_free(rqd, rrpc->rq_pool); + return NULL; + } + + return rqd; +} + +static void rrpc_inflight_laddr_release(struct rrpc *rrpc, struct nvm_rq *rqd) +{ + struct rrpc_inflight_rq *inf = rrpc_get_inflight_rq(rqd); + + rrpc_unlock_laddr(rrpc, inf); + + mempool_free(rqd, rrpc->rq_pool); +} + +static void rrpc_discard(struct rrpc *rrpc, struct bio *bio) +{ + sector_t slba = bio->bi_iter.bi_sector / NR_PHY_IN_LOG; + sector_t len = bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE; + struct nvm_rq *rqd; + + do { + rqd = rrpc_inflight_laddr_acquire(rrpc, slba, len); + schedule(); + } while (!rqd); + + if (IS_ERR(rqd)) { + pr_err("rrpc: unable to acquire inflight IO\n"); + bio_io_error(bio); + return; + } + + rrpc_invalidate_range(rrpc, slba, len); + rrpc_inflight_laddr_release(rrpc, rqd); +} + +static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk) +{ + return (rblk->next_page == rrpc->dev->pgs_per_blk); +} + +static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk) +{ + struct nvm_block *blk = rblk->parent; + + return blk->id * rrpc->dev->pgs_per_blk; +} + +static struct ppa_addr linear_to_generic_addr(struct nvm_dev *dev, + struct ppa_addr r) +{ + struct ppa_addr l; + int secs, pgs, blks, luns; + sector_t ppa = r.ppa; + + l.ppa = 0; + + div_u64_rem(ppa, dev->sec_per_pg, &secs); + l.g.sec = secs; + + sector_div(ppa, dev->sec_per_pg); + div_u64_rem(ppa, dev->sec_per_blk, &pgs); + l.g.pg = pgs; + + sector_div(ppa, dev->pgs_per_blk); + div_u64_rem(ppa, dev->blks_per_lun, &blks); + l.g.blk = blks; + + sector_div(ppa, dev->blks_per_lun); + div_u64_rem(ppa, dev->luns_per_chnl, &luns); + l.g.lun = luns; + + sector_div(ppa, dev->luns_per_chnl); + l.g.ch = ppa; + + return l; +} + +static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr) +{ + struct ppa_addr paddr; + + paddr.ppa = addr; + return linear_to_generic_addr(dev, paddr); +} + +/* requires lun->lock taken */ +static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *rblk) +{ + struct rrpc *rrpc = rlun->rrpc; + + BUG_ON(!rblk); + + if (rlun->cur) { + spin_lock(&rlun->cur->lock); + WARN_ON(!block_is_full(rrpc, rlun->cur)); + spin_unlock(&rlun->cur->lock); + } + rlun->cur = rblk; +} + +static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun, + unsigned long flags) +{ + struct nvm_block *blk; + struct rrpc_block *rblk; + + blk = nvm_get_blk(rrpc->dev, rlun->parent, flags); + if (!blk) + return NULL; + + rblk = &rlun->blocks[blk->id]; + blk->priv = rblk; + + bitmap_zero(rblk->invalid_pages, rrpc->dev->pgs_per_blk); + rblk->next_page = 0; + rblk->nr_invalid_pages = 0; + atomic_set(&rblk->data_cmnt_size, 0); + + return rblk; +} + +static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk) +{ + nvm_put_blk(rrpc->dev, rblk->parent); +} + +static void rrpc_put_blks(struct rrpc *rrpc) +{ + struct rrpc_lun *rlun; + int i; + + for (i = 0; i < rrpc->nr_luns; i++) { + rlun = &rrpc->luns[i]; + if (rlun->cur) + rrpc_put_blk(rrpc, rlun->cur); + if (rlun->gc_cur) + rrpc_put_blk(rrpc, rlun->gc_cur); + } +} + +static struct rrpc_lun *get_next_lun(struct rrpc *rrpc) +{ + int next = atomic_inc_return(&rrpc->next_lun); + + return &rrpc->luns[next % rrpc->nr_luns]; +} + +static void rrpc_gc_kick(struct rrpc *rrpc) +{ + struct rrpc_lun *rlun; + unsigned int i; + + for (i = 0; i < rrpc->nr_luns; i++) { + rlun = &rrpc->luns[i]; + queue_work(rrpc->krqd_wq, &rlun->ws_gc); + } +} + +/* + * timed GC every interval. + */ +static void rrpc_gc_timer(unsigned long data) +{ + struct rrpc *rrpc = (struct rrpc *)data; + + rrpc_gc_kick(rrpc); + mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10)); +} + +static void rrpc_end_sync_bio(struct bio *bio) +{ + struct completion *waiting = bio->bi_private; + + if (bio->bi_error) + pr_err("nvm: gc request failed (%u).\n", bio->bi_error); + + complete(waiting); +} + +/* + * rrpc_move_valid_pages -- migrate live data off the block + * @rrpc: the 'rrpc' structure + * @block: the block from which to migrate live pages + * + * Description: + * GC algorithms may call this function to migrate remaining live + * pages off the block prior to erasing it. This function blocks + * further execution until the operation is complete. + */ +static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk) +{ + struct request_queue *q = rrpc->dev->q; + struct rrpc_rev_addr *rev; + struct nvm_rq *rqd; + struct bio *bio; + struct page *page; + int slot; + int nr_pgs_per_blk = rrpc->dev->pgs_per_blk; + u64 phys_addr; + DECLARE_COMPLETION_ONSTACK(wait); + + if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) + return 0; + + bio = bio_alloc(GFP_NOIO, 1); + if (!bio) { + pr_err("nvm: could not alloc bio to gc\n"); + return -ENOMEM; + } + + page = mempool_alloc(rrpc->page_pool, GFP_NOIO); + + while ((slot = find_first_zero_bit(rblk->invalid_pages, + nr_pgs_per_blk)) < nr_pgs_per_blk) { + + /* Lock laddr */ + phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot; + +try: + spin_lock(&rrpc->rev_lock); + /* Get logical address from physical to logical table */ + rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset]; + /* already updated by previous regular write */ + if (rev->addr == ADDR_EMPTY) { + spin_unlock(&rrpc->rev_lock); + continue; + } + + rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1); + if (IS_ERR_OR_NULL(rqd)) { + spin_unlock(&rrpc->rev_lock); + schedule(); + goto try; + } + + spin_unlock(&rrpc->rev_lock); + + /* Perform read to do GC */ + bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr); + bio->bi_rw = READ; + bio->bi_private = &wait; + bio->bi_end_io = rrpc_end_sync_bio; + + /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */ + bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0); + + if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) { + pr_err("rrpc: gc read failed.\n"); + rrpc_inflight_laddr_release(rrpc, rqd); + goto finished; + } + wait_for_completion_io(&wait); + + bio_reset(bio); + reinit_completion(&wait); + + bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr); + bio->bi_rw = WRITE; + bio->bi_private = &wait; + bio->bi_end_io = rrpc_end_sync_bio; + + bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0); + + /* turn the command around and write the data back to a new + * address + */ + if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) { + pr_err("rrpc: gc write failed.\n"); + rrpc_inflight_laddr_release(rrpc, rqd); + goto finished; + } + wait_for_completion_io(&wait); + + rrpc_inflight_laddr_release(rrpc, rqd); + + bio_reset(bio); + } + +finished: + mempool_free(page, rrpc->page_pool); + bio_put(bio); + + if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) { + pr_err("nvm: failed to garbage collect block\n"); + return -EIO; + } + + return 0; +} + +static void rrpc_block_gc(struct work_struct *work) +{ + struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc, + ws_gc); + struct rrpc *rrpc = gcb->rrpc; + struct rrpc_block *rblk = gcb->rblk; + struct nvm_dev *dev = rrpc->dev; + + pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id); + + if (rrpc_move_valid_pages(rrpc, rblk)) + goto done; + + nvm_erase_blk(dev, rblk->parent); + rrpc_put_blk(rrpc, rblk); +done: + mempool_free(gcb, rrpc->gcb_pool); +} + +/* the block with highest number of invalid pages, will be in the beginning + * of the list + */ +static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra, + struct rrpc_block *rb) +{ + if (ra->nr_invalid_pages == rb->nr_invalid_pages) + return ra; + + return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra; +} + +/* linearly find the block with highest number of invalid pages + * requires lun->lock + */ +static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun) +{ + struct list_head *prio_list = &rlun->prio_list; + struct rrpc_block *rblock, *max; + + BUG_ON(list_empty(prio_list)); + + max = list_first_entry(prio_list, struct rrpc_block, prio); + list_for_each_entry(rblock, prio_list, prio) + max = rblock_max_invalid(max, rblock); + + return max; +} + +static void rrpc_lun_gc(struct work_struct *work) +{ + struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc); + struct rrpc *rrpc = rlun->rrpc; + struct nvm_lun *lun = rlun->parent; + struct rrpc_block_gc *gcb; + unsigned int nr_blocks_need; + + nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE; + + if (nr_blocks_need < rrpc->nr_luns) + nr_blocks_need = rrpc->nr_luns; + + spin_lock(&lun->lock); + while (nr_blocks_need > lun->nr_free_blocks && + !list_empty(&rlun->prio_list)) { + struct rrpc_block *rblock = block_prio_find_max(rlun); + struct nvm_block *block = rblock->parent; + + if (!rblock->nr_invalid_pages) + break; + + list_del_init(&rblock->prio); + + BUG_ON(!block_is_full(rrpc, rblock)); + + pr_debug("rrpc: selected block '%lu' for GC\n", block->id); + + gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC); + if (!gcb) + break; + + gcb->rrpc = rrpc; + gcb->rblk = rblock; + INIT_WORK(&gcb->ws_gc, rrpc_block_gc); + + queue_work(rrpc->kgc_wq, &gcb->ws_gc); + + nr_blocks_need--; + } + spin_unlock(&lun->lock); + + /* TODO: Hint that request queue can be started again */ +} + +static void rrpc_gc_queue(struct work_struct *work) +{ + struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc, + ws_gc); + struct rrpc *rrpc = gcb->rrpc; + struct rrpc_block *rblk = gcb->rblk; + struct nvm_lun *lun = rblk->parent->lun; + struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset]; + + spin_lock(&rlun->lock); + list_add_tail(&rblk->prio, &rlun->prio_list); + spin_unlock(&rlun->lock); + + mempool_free(gcb, rrpc->gcb_pool); + pr_debug("nvm: block '%lu' is full, allow GC (sched)\n", + rblk->parent->id); +} + +static const struct block_device_operations rrpc_fops = { + .owner = THIS_MODULE, +}; + +static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc) +{ + unsigned int i; + struct rrpc_lun *rlun, *max_free; + + if (!is_gc) + return get_next_lun(rrpc); + + /* during GC, we don't care about RR, instead we want to make + * sure that we maintain evenness between the block luns. + */ + max_free = &rrpc->luns[0]; + /* prevent GC-ing lun from devouring pages of a lun with + * little free blocks. We don't take the lock as we only need an + * estimate. + */ + rrpc_for_each_lun(rrpc, rlun, i) { + if (rlun->parent->nr_free_blocks > + max_free->parent->nr_free_blocks) + max_free = rlun; + } + + return max_free; +} + +static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr, + struct rrpc_block *rblk, u64 paddr) +{ + struct rrpc_addr *gp; + struct rrpc_rev_addr *rev; + + BUG_ON(laddr >= rrpc->nr_pages); + + gp = &rrpc->trans_map[laddr]; + spin_lock(&rrpc->rev_lock); + if (gp->rblk) + rrpc_page_invalidate(rrpc, gp); + + gp->addr = paddr; + gp->rblk = rblk; + + rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset]; + rev->addr = laddr; + spin_unlock(&rrpc->rev_lock); + + return gp; +} + +static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk) +{ + u64 addr = ADDR_EMPTY; + + spin_lock(&rblk->lock); + if (block_is_full(rrpc, rblk)) + goto out; + + addr = block_to_addr(rrpc, rblk) + rblk->next_page; + + rblk->next_page++; +out: + spin_unlock(&rblk->lock); + return addr; +} + +/* Simple round-robin Logical to physical address translation. + * + * Retrieve the mapping using the active append point. Then update the ap for + * the next write to the disk. + * + * Returns rrpc_addr with the physical address and block. Remember to return to + * rrpc->addr_cache when request is finished. + */ +static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr, + int is_gc) +{ + struct rrpc_lun *rlun; + struct rrpc_block *rblk; + struct nvm_lun *lun; + u64 paddr; + + rlun = rrpc_get_lun_rr(rrpc, is_gc); + lun = rlun->parent; + + if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4) + return NULL; + + spin_lock(&rlun->lock); + + rblk = rlun->cur; +retry: + paddr = rrpc_alloc_addr(rrpc, rblk); + + if (paddr == ADDR_EMPTY) { + rblk = rrpc_get_blk(rrpc, rlun, 0); + if (rblk) { + rrpc_set_lun_cur(rlun, rblk); + goto retry; + } + + if (is_gc) { + /* retry from emergency gc block */ + paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur); + if (paddr == ADDR_EMPTY) { + rblk = rrpc_get_blk(rrpc, rlun, 1); + if (!rblk) { + pr_err("rrpc: no more blocks"); + goto err; + } + + rlun->gc_cur = rblk; + paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur); + } + rblk = rlun->gc_cur; + } + } + + spin_unlock(&rlun->lock); + return rrpc_update_map(rrpc, laddr, rblk, paddr); +err: + spin_unlock(&rlun->lock); + return NULL; +} + +static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk) +{ + struct rrpc_block_gc *gcb; + + gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC); + if (!gcb) { + pr_err("rrpc: unable to queue block for gc."); + return; + } + + gcb->rrpc = rrpc; + gcb->rblk = rblk; + + INIT_WORK(&gcb->ws_gc, rrpc_gc_queue); + queue_work(rrpc->kgc_wq, &gcb->ws_gc); +} + +static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd, + sector_t laddr, uint8_t npages) +{ + struct rrpc_addr *p; + struct rrpc_block *rblk; + struct nvm_lun *lun; + int cmnt_size, i; + + for (i = 0; i < npages; i++) { + p = &rrpc->trans_map[laddr + i]; + rblk = p->rblk; + lun = rblk->parent->lun; + + cmnt_size = atomic_inc_return(&rblk->data_cmnt_size); + if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk)) + rrpc_run_gc(rrpc, rblk); + } +} + +static int rrpc_end_io(struct nvm_rq *rqd, int error) +{ + struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance); + struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd); + uint8_t npages = rqd->nr_pages; + sector_t laddr = rrpc_get_laddr(rqd->bio) - npages; + + if (bio_data_dir(rqd->bio) == WRITE) + rrpc_end_io_write(rrpc, rrqd, laddr, npages); + + if (rrqd->flags & NVM_IOTYPE_GC) + return 0; + + rrpc_unlock_rq(rrpc, rqd); + bio_put(rqd->bio); + + if (npages > 1) + nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list); + if (rqd->metadata) + nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata); + + mempool_free(rqd, rrpc->rq_pool); + + return 0; +} + +static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio, + struct nvm_rq *rqd, unsigned long flags, int npages) +{ + struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd); + struct rrpc_addr *gp; + sector_t laddr = rrpc_get_laddr(bio); + int is_gc = flags & NVM_IOTYPE_GC; + int i; + + if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) { + nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list); + return NVM_IO_REQUEUE; + } + + for (i = 0; i < npages; i++) { + /* We assume that mapping occurs at 4KB granularity */ + BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages)); + gp = &rrpc->trans_map[laddr + i]; + + if (gp->rblk) { + rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev, + gp->addr); + } else { + BUG_ON(is_gc); + rrpc_unlock_laddr(rrpc, r); + nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, + rqd->dma_ppa_list); + return NVM_IO_DONE; + } + } + + rqd->opcode = NVM_OP_HBREAD; + + return NVM_IO_OK; +} + +static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd, + unsigned long flags) +{ + struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd); + int is_gc = flags & NVM_IOTYPE_GC; + sector_t laddr = rrpc_get_laddr(bio); + struct rrpc_addr *gp; + + if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) + return NVM_IO_REQUEUE; + + BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages)); + gp = &rrpc->trans_map[laddr]; + + if (gp->rblk) { + rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr); + } else { + BUG_ON(is_gc); + rrpc_unlock_rq(rrpc, rqd); + return NVM_IO_DONE; + } + + rqd->opcode = NVM_OP_HBREAD; + rrqd->addr = gp; + + return NVM_IO_OK; +} + +static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio, + struct nvm_rq *rqd, unsigned long flags, int npages) +{ + struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd); + struct rrpc_addr *p; + sector_t laddr = rrpc_get_laddr(bio); + int is_gc = flags & NVM_IOTYPE_GC; + int i; + + if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) { + nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list); + return NVM_IO_REQUEUE; + } + + for (i = 0; i < npages; i++) { + /* We assume that mapping occurs at 4KB granularity */ + p = rrpc_map_page(rrpc, laddr + i, is_gc); + if (!p) { + BUG_ON(is_gc); + rrpc_unlock_laddr(rrpc, r); + nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, + rqd->dma_ppa_list); + rrpc_gc_kick(rrpc); + return NVM_IO_REQUEUE; + } + + rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev, + p->addr); + } + + rqd->opcode = NVM_OP_HBWRITE; + + return NVM_IO_OK; +} + +static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio, + struct nvm_rq *rqd, unsigned long flags) +{ + struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd); + struct rrpc_addr *p; + int is_gc = flags & NVM_IOTYPE_GC; + sector_t laddr = rrpc_get_laddr(bio); + + if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) + return NVM_IO_REQUEUE; + + p = rrpc_map_page(rrpc, laddr, is_gc); + if (!p) { + BUG_ON(is_gc); + rrpc_unlock_rq(rrpc, rqd); + rrpc_gc_kick(rrpc); + return NVM_IO_REQUEUE; + } + + rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr); + rqd->opcode = NVM_OP_HBWRITE; + rrqd->addr = p; + + return NVM_IO_OK; +} + +static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio, + struct nvm_rq *rqd, unsigned long flags, uint8_t npages) +{ + if (npages > 1) { + rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL, + &rqd->dma_ppa_list); + if (!rqd->ppa_list) { + pr_err("rrpc: not able to allocate ppa list\n"); + return NVM_IO_ERR; + } + + if (bio_rw(bio) == WRITE) + return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags, + npages); + + return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages); + } + + if (bio_rw(bio) == WRITE) + return rrpc_write_rq(rrpc, bio, rqd, flags); + + return rrpc_read_rq(rrpc, bio, rqd, flags); +} + +static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio, + struct nvm_rq *rqd, unsigned long flags) +{ + int err; + struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd); + uint8_t nr_pages = rrpc_get_pages(bio); + int bio_size = bio_sectors(bio) << 9; + + if (bio_size < rrpc->dev->sec_size) + return NVM_IO_ERR; + else if (bio_size > rrpc->dev->max_rq_size) + return NVM_IO_ERR; + + err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages); + if (err) + return err; + + bio_get(bio); + rqd->bio = bio; + rqd->ins = &rrpc->instance; + rqd->nr_pages = nr_pages; + rrq->flags = flags; + + err = nvm_submit_io(rrpc->dev, rqd); + if (err) { + pr_err("rrpc: I/O submission failed: %d\n", err); + return NVM_IO_ERR; + } + + return NVM_IO_OK; +} + +static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio) +{ + struct rrpc *rrpc = q->queuedata; + struct nvm_rq *rqd; + int err; + + if (bio->bi_rw & REQ_DISCARD) { + rrpc_discard(rrpc, bio); + return BLK_QC_T_NONE; + } + + rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL); + if (!rqd) { + pr_err_ratelimited("rrpc: not able to queue bio."); + bio_io_error(bio); + return BLK_QC_T_NONE; + } + memset(rqd, 0, sizeof(struct nvm_rq)); + + err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE); + switch (err) { + case NVM_IO_OK: + return BLK_QC_T_NONE; + case NVM_IO_ERR: + bio_io_error(bio); + break; + case NVM_IO_DONE: + bio_endio(bio); + break; + case NVM_IO_REQUEUE: + spin_lock(&rrpc->bio_lock); + bio_list_add(&rrpc->requeue_bios, bio); + spin_unlock(&rrpc->bio_lock); + queue_work(rrpc->kgc_wq, &rrpc->ws_requeue); + break; + } + + mempool_free(rqd, rrpc->rq_pool); + return BLK_QC_T_NONE; +} + +static void rrpc_requeue(struct work_struct *work) +{ + struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue); + struct bio_list bios; + struct bio *bio; + + bio_list_init(&bios); + + spin_lock(&rrpc->bio_lock); + bio_list_merge(&bios, &rrpc->requeue_bios); + bio_list_init(&rrpc->requeue_bios); + spin_unlock(&rrpc->bio_lock); + + while ((bio = bio_list_pop(&bios))) + rrpc_make_rq(rrpc->disk->queue, bio); +} + +static void rrpc_gc_free(struct rrpc *rrpc) +{ + struct rrpc_lun *rlun; + int i; + + if (rrpc->krqd_wq) + destroy_workqueue(rrpc->krqd_wq); + + if (rrpc->kgc_wq) + destroy_workqueue(rrpc->kgc_wq); + + if (!rrpc->luns) + return; + + for (i = 0; i < rrpc->nr_luns; i++) { + rlun = &rrpc->luns[i]; + + if (!rlun->blocks) + break; + vfree(rlun->blocks); + } +} + +static int rrpc_gc_init(struct rrpc *rrpc) +{ + rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND, + rrpc->nr_luns); + if (!rrpc->krqd_wq) + return -ENOMEM; + + rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1); + if (!rrpc->kgc_wq) + return -ENOMEM; + + setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc); + + return 0; +} + +static void rrpc_map_free(struct rrpc *rrpc) +{ + vfree(rrpc->rev_trans_map); + vfree(rrpc->trans_map); +} + +static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private) +{ + struct rrpc *rrpc = (struct rrpc *)private; + struct nvm_dev *dev = rrpc->dev; + struct rrpc_addr *addr = rrpc->trans_map + slba; + struct rrpc_rev_addr *raddr = rrpc->rev_trans_map; + sector_t max_pages = dev->total_pages * (dev->sec_size >> 9); + u64 elba = slba + nlb; + u64 i; + + if (unlikely(elba > dev->total_pages)) { + pr_err("nvm: L2P data from device is out of bounds!\n"); + return -EINVAL; + } + + for (i = 0; i < nlb; i++) { + u64 pba = le64_to_cpu(entries[i]); + /* LNVM treats address-spaces as silos, LBA and PBA are + * equally large and zero-indexed. + */ + if (unlikely(pba >= max_pages && pba != U64_MAX)) { + pr_err("nvm: L2P data entry is out of bounds!\n"); + return -EINVAL; + } + + /* Address zero is a special one. The first page on a disk is + * protected. As it often holds internal device boot + * information. + */ + if (!pba) + continue; + + addr[i].addr = pba; + raddr[pba].addr = slba + i; + } + + return 0; +} + +static int rrpc_map_init(struct rrpc *rrpc) +{ + struct nvm_dev *dev = rrpc->dev; + sector_t i; + int ret; + + rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages); + if (!rrpc->trans_map) + return -ENOMEM; + + rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr) + * rrpc->nr_pages); + if (!rrpc->rev_trans_map) + return -ENOMEM; + + for (i = 0; i < rrpc->nr_pages; i++) { + struct rrpc_addr *p = &rrpc->trans_map[i]; + struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i]; + + p->addr = ADDR_EMPTY; + r->addr = ADDR_EMPTY; + } + + if (!dev->ops->get_l2p_tbl) + return 0; + + /* Bring up the mapping table from device */ + ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages, + rrpc_l2p_update, rrpc); + if (ret) { + pr_err("nvm: rrpc: could not read L2P table.\n"); + return -EINVAL; + } + + return 0; +} + + +/* Minimum pages needed within a lun */ +#define PAGE_POOL_SIZE 16 +#define ADDR_POOL_SIZE 64 + +static int rrpc_core_init(struct rrpc *rrpc) +{ + down_write(&rrpc_lock); + if (!rrpc_gcb_cache) { + rrpc_gcb_cache = kmem_cache_create("rrpc_gcb", + sizeof(struct rrpc_block_gc), 0, 0, NULL); + if (!rrpc_gcb_cache) { + up_write(&rrpc_lock); + return -ENOMEM; + } + + rrpc_rq_cache = kmem_cache_create("rrpc_rq", + sizeof(struct nvm_rq) + sizeof(struct rrpc_rq), + 0, 0, NULL); + if (!rrpc_rq_cache) { + kmem_cache_destroy(rrpc_gcb_cache); + up_write(&rrpc_lock); + return -ENOMEM; + } + } + up_write(&rrpc_lock); + + rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0); + if (!rrpc->page_pool) + return -ENOMEM; + + rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns, + rrpc_gcb_cache); + if (!rrpc->gcb_pool) + return -ENOMEM; + + rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache); + if (!rrpc->rq_pool) + return -ENOMEM; + + spin_lock_init(&rrpc->inflights.lock); + INIT_LIST_HEAD(&rrpc->inflights.reqs); + + return 0; +} + +static void rrpc_core_free(struct rrpc *rrpc) +{ + mempool_destroy(rrpc->page_pool); + mempool_destroy(rrpc->gcb_pool); + mempool_destroy(rrpc->rq_pool); +} + +static void rrpc_luns_free(struct rrpc *rrpc) +{ + kfree(rrpc->luns); +} + +static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end) +{ + struct nvm_dev *dev = rrpc->dev; + struct rrpc_lun *rlun; + int i, j; + + spin_lock_init(&rrpc->rev_lock); + + rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun), + GFP_KERNEL); + if (!rrpc->luns) + return -ENOMEM; + + /* 1:1 mapping */ + for (i = 0; i < rrpc->nr_luns; i++) { + struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i); + + if (dev->pgs_per_blk > + MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) { + pr_err("rrpc: number of pages per block too high."); + goto err; + } + + rlun = &rrpc->luns[i]; + rlun->rrpc = rrpc; + rlun->parent = lun; + INIT_LIST_HEAD(&rlun->prio_list); + INIT_WORK(&rlun->ws_gc, rrpc_lun_gc); + spin_lock_init(&rlun->lock); + + rrpc->total_blocks += dev->blks_per_lun; + rrpc->nr_pages += dev->sec_per_lun; + + rlun->blocks = vzalloc(sizeof(struct rrpc_block) * + rrpc->dev->blks_per_lun); + if (!rlun->blocks) + goto err; + + for (j = 0; j < rrpc->dev->blks_per_lun; j++) { + struct rrpc_block *rblk = &rlun->blocks[j]; + struct nvm_block *blk = &lun->blocks[j]; + + rblk->parent = blk; + INIT_LIST_HEAD(&rblk->prio); + spin_lock_init(&rblk->lock); + } + } + + return 0; +err: + return -ENOMEM; +} + +static void rrpc_free(struct rrpc *rrpc) +{ + rrpc_gc_free(rrpc); + rrpc_map_free(rrpc); + rrpc_core_free(rrpc); + rrpc_luns_free(rrpc); + + kfree(rrpc); +} + +static void rrpc_exit(void *private) +{ + struct rrpc *rrpc = private; + + del_timer(&rrpc->gc_timer); + + flush_workqueue(rrpc->krqd_wq); + flush_workqueue(rrpc->kgc_wq); + + rrpc_free(rrpc); +} + +static sector_t rrpc_capacity(void *private) +{ + struct rrpc *rrpc = private; + struct nvm_dev *dev = rrpc->dev; + sector_t reserved, provisioned; + + /* cur, gc, and two emergency blocks for each lun */ + reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4; + provisioned = rrpc->nr_pages - reserved; + + if (reserved > rrpc->nr_pages) { + pr_err("rrpc: not enough space available to expose storage.\n"); + return 0; + } + + sector_div(provisioned, 10); + return provisioned * 9 * NR_PHY_IN_LOG; +} + +/* + * Looks up the logical address from reverse trans map and check if its valid by + * comparing the logical to physical address with the physical address. + * Returns 0 on free, otherwise 1 if in use + */ +static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk) +{ + struct nvm_dev *dev = rrpc->dev; + int offset; + struct rrpc_addr *laddr; + u64 paddr, pladdr; + + for (offset = 0; offset < dev->pgs_per_blk; offset++) { + paddr = block_to_addr(rrpc, rblk) + offset; + + pladdr = rrpc->rev_trans_map[paddr].addr; + if (pladdr == ADDR_EMPTY) + continue; + + laddr = &rrpc->trans_map[pladdr]; + + if (paddr == laddr->addr) { + laddr->rblk = rblk; + } else { + set_bit(offset, rblk->invalid_pages); + rblk->nr_invalid_pages++; + } + } +} + +static int rrpc_blocks_init(struct rrpc *rrpc) +{ + struct rrpc_lun *rlun; + struct rrpc_block *rblk; + int lun_iter, blk_iter; + + for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) { + rlun = &rrpc->luns[lun_iter]; + + for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun; + blk_iter++) { + rblk = &rlun->blocks[blk_iter]; + rrpc_block_map_update(rrpc, rblk); + } + } + + return 0; +} + +static int rrpc_luns_configure(struct rrpc *rrpc) +{ + struct rrpc_lun *rlun; + struct rrpc_block *rblk; + int i; + + for (i = 0; i < rrpc->nr_luns; i++) { + rlun = &rrpc->luns[i]; + + rblk = rrpc_get_blk(rrpc, rlun, 0); + if (!rblk) + goto err; + + rrpc_set_lun_cur(rlun, rblk); + + /* Emergency gc block */ + rblk = rrpc_get_blk(rrpc, rlun, 1); + if (!rblk) + goto err; + rlun->gc_cur = rblk; + } + + return 0; +err: + rrpc_put_blks(rrpc); + return -EINVAL; +} + +static struct nvm_tgt_type tt_rrpc; + +static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk, + int lun_begin, int lun_end) +{ + struct request_queue *bqueue = dev->q; + struct request_queue *tqueue = tdisk->queue; + struct rrpc *rrpc; + int ret; + + if (!(dev->identity.dom & NVM_RSP_L2P)) { + pr_err("nvm: rrpc: device does not support l2p (%x)\n", + dev->identity.dom); + return ERR_PTR(-EINVAL); + } + + rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL); + if (!rrpc) + return ERR_PTR(-ENOMEM); + + rrpc->instance.tt = &tt_rrpc; + rrpc->dev = dev; + rrpc->disk = tdisk; + + bio_list_init(&rrpc->requeue_bios); + spin_lock_init(&rrpc->bio_lock); + INIT_WORK(&rrpc->ws_requeue, rrpc_requeue); + + rrpc->nr_luns = lun_end - lun_begin + 1; + + /* simple round-robin strategy */ + atomic_set(&rrpc->next_lun, -1); + + ret = rrpc_luns_init(rrpc, lun_begin, lun_end); + if (ret) { + pr_err("nvm: rrpc: could not initialize luns\n"); + goto err; + } + + rrpc->poffset = dev->sec_per_lun * lun_begin; + rrpc->lun_offset = lun_begin; + + ret = rrpc_core_init(rrpc); + if (ret) { + pr_err("nvm: rrpc: could not initialize core\n"); + goto err; + } + + ret = rrpc_map_init(rrpc); + if (ret) { + pr_err("nvm: rrpc: could not initialize maps\n"); + goto err; + } + + ret = rrpc_blocks_init(rrpc); + if (ret) { + pr_err("nvm: rrpc: could not initialize state for blocks\n"); + goto err; + } + + ret = rrpc_luns_configure(rrpc); + if (ret) { + pr_err("nvm: rrpc: not enough blocks available in LUNs.\n"); + goto err; + } + + ret = rrpc_gc_init(rrpc); + if (ret) { + pr_err("nvm: rrpc: could not initialize gc\n"); + goto err; + } + + /* inherit the size from the underlying device */ + blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue)); + blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue)); + + pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n", + rrpc->nr_luns, (unsigned long long)rrpc->nr_pages); + + mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10)); + + return rrpc; +err: + rrpc_free(rrpc); + return ERR_PTR(ret); +} + +/* round robin, page-based FTL, and cost-based GC */ +static struct nvm_tgt_type tt_rrpc = { + .name = "rrpc", + .version = {1, 0, 0}, + + .make_rq = rrpc_make_rq, + .capacity = rrpc_capacity, + .end_io = rrpc_end_io, + + .init = rrpc_init, + .exit = rrpc_exit, +}; + +static int __init rrpc_module_init(void) +{ + return nvm_register_target(&tt_rrpc); +} + +static void rrpc_module_exit(void) +{ + nvm_unregister_target(&tt_rrpc); +} + +module_init(rrpc_module_init); +module_exit(rrpc_module_exit); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs"); |