291 lines
6.9 KiB
C
291 lines
6.9 KiB
C
/*
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* Copyright (C) 2015 IT University of Copenhagen
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* Initial release: Matias Bjorling <m@bjorling.me>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
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*/
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#ifndef RRPC_H_
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#define RRPC_H_
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#include <linux/blkdev.h>
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#include <linux/blk-mq.h>
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#include <linux/bio.h>
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#include <linux/module.h>
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#include <linux/kthread.h>
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#include <linux/vmalloc.h>
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#include <linux/lightnvm.h>
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/* Run only GC if less than 1/X blocks are free */
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#define GC_LIMIT_INVERSE 10
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#define GC_TIME_SECS 100
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#define RRPC_SECTOR (512)
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#define RRPC_EXPOSED_PAGE_SIZE (4096)
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#define NR_PHY_IN_LOG (RRPC_EXPOSED_PAGE_SIZE / RRPC_SECTOR)
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struct rrpc_inflight {
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struct list_head reqs;
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spinlock_t lock;
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};
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struct rrpc_inflight_rq {
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struct list_head list;
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sector_t l_start;
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sector_t l_end;
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};
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struct rrpc_rq {
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struct rrpc_inflight_rq inflight_rq;
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unsigned long flags;
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};
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struct rrpc_block {
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int id; /* id inside of LUN */
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struct rrpc_lun *rlun;
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struct list_head prio; /* LUN CG list */
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struct list_head list; /* LUN free, used, bb list */
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#define MAX_INVALID_PAGES_STORAGE 8
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/* Bitmap for invalid page intries */
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unsigned long invalid_pages[MAX_INVALID_PAGES_STORAGE];
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/* points to the next writable page within a block */
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unsigned int next_page;
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/* number of pages that are invalid, wrt host page size */
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unsigned int nr_invalid_pages;
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int state;
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spinlock_t lock;
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atomic_t data_cmnt_size; /* data pages committed to stable storage */
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};
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struct rrpc_lun {
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struct rrpc *rrpc;
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int id;
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struct ppa_addr bppa;
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struct rrpc_block *cur, *gc_cur;
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struct rrpc_block *blocks; /* Reference to block allocation */
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struct list_head prio_list; /* Blocks that may be GC'ed */
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struct list_head wblk_list; /* Queued blocks to be written to */
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/* lun block lists */
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struct list_head used_list; /* In-use blocks */
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struct list_head free_list; /* Not used blocks i.e. released
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* and ready for use
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*/
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struct list_head bb_list; /* Bad blocks. Mutually exclusive with
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* free_list and used_list
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*/
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unsigned int nr_free_blocks; /* Number of unused blocks */
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struct work_struct ws_gc;
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int reserved_blocks;
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spinlock_t lock;
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};
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struct rrpc {
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struct nvm_tgt_dev *dev;
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struct gendisk *disk;
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sector_t soffset; /* logical sector offset */
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int nr_luns;
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struct rrpc_lun *luns;
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/* calculated values */
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unsigned long long nr_sects;
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/* Write strategy variables. Move these into each for structure for each
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* strategy
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*/
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atomic_t next_lun; /* Whenever a page is written, this is updated
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* to point to the next write lun
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*/
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spinlock_t bio_lock;
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struct bio_list requeue_bios;
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struct work_struct ws_requeue;
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/* Simple translation map of logical addresses to physical addresses.
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* The logical addresses is known by the host system, while the physical
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* addresses are used when writing to the disk block device.
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*/
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struct rrpc_addr *trans_map;
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/* also store a reverse map for garbage collection */
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struct rrpc_rev_addr *rev_trans_map;
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spinlock_t rev_lock;
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struct rrpc_inflight inflights;
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mempool_t *addr_pool;
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mempool_t *page_pool;
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mempool_t *gcb_pool;
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mempool_t *rq_pool;
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struct timer_list gc_timer;
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struct workqueue_struct *krqd_wq;
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struct workqueue_struct *kgc_wq;
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};
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struct rrpc_block_gc {
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struct rrpc *rrpc;
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struct rrpc_block *rblk;
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struct work_struct ws_gc;
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};
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/* Logical to physical mapping */
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struct rrpc_addr {
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u64 addr;
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struct rrpc_block *rblk;
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};
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/* Physical to logical mapping */
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struct rrpc_rev_addr {
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u64 addr;
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};
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static inline struct ppa_addr rrpc_linear_to_generic_addr(struct nvm_geo *geo,
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struct ppa_addr r)
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{
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struct ppa_addr l;
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int secs, pgs;
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sector_t ppa = r.ppa;
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l.ppa = 0;
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div_u64_rem(ppa, geo->sec_per_pg, &secs);
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l.g.sec = secs;
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sector_div(ppa, geo->sec_per_pg);
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div_u64_rem(ppa, geo->pgs_per_blk, &pgs);
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l.g.pg = pgs;
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return l;
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}
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static inline struct ppa_addr rrpc_recov_addr(struct nvm_tgt_dev *dev, u64 pba)
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{
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return linear_to_generic_addr(&dev->geo, pba);
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}
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static inline u64 rrpc_blk_to_ppa(struct rrpc *rrpc, struct rrpc_block *rblk)
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{
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struct nvm_tgt_dev *dev = rrpc->dev;
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struct nvm_geo *geo = &dev->geo;
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struct rrpc_lun *rlun = rblk->rlun;
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return (rlun->id * geo->sec_per_lun) + (rblk->id * geo->sec_per_blk);
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}
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static inline sector_t rrpc_get_laddr(struct bio *bio)
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{
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return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
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}
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static inline unsigned int rrpc_get_pages(struct bio *bio)
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{
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return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
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}
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static inline sector_t rrpc_get_sector(sector_t laddr)
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{
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return laddr * NR_PHY_IN_LOG;
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}
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static inline int request_intersects(struct rrpc_inflight_rq *r,
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sector_t laddr_start, sector_t laddr_end)
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{
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return (laddr_end >= r->l_start) && (laddr_start <= r->l_end);
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}
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static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
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unsigned int pages, struct rrpc_inflight_rq *r)
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{
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sector_t laddr_end = laddr + pages - 1;
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struct rrpc_inflight_rq *rtmp;
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WARN_ON(irqs_disabled());
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spin_lock_irq(&rrpc->inflights.lock);
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list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
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if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
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/* existing, overlapping request, come back later */
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spin_unlock_irq(&rrpc->inflights.lock);
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return 1;
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}
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}
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r->l_start = laddr;
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r->l_end = laddr_end;
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list_add_tail(&r->list, &rrpc->inflights.reqs);
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spin_unlock_irq(&rrpc->inflights.lock);
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return 0;
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}
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static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
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unsigned int pages,
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struct rrpc_inflight_rq *r)
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{
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BUG_ON((laddr + pages) > rrpc->nr_sects);
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return __rrpc_lock_laddr(rrpc, laddr, pages, r);
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}
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static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd)
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{
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struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
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return &rrqd->inflight_rq;
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}
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static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio,
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struct nvm_rq *rqd)
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{
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sector_t laddr = rrpc_get_laddr(bio);
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unsigned int pages = rrpc_get_pages(bio);
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struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
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return rrpc_lock_laddr(rrpc, laddr, pages, r);
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}
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static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
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struct rrpc_inflight_rq *r)
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{
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unsigned long flags;
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spin_lock_irqsave(&rrpc->inflights.lock, flags);
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list_del_init(&r->list);
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spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
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}
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static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd)
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{
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struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
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uint8_t pages = rqd->nr_ppas;
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BUG_ON((r->l_start + pages) > rrpc->nr_sects);
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rrpc_unlock_laddr(rrpc, r);
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}
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#endif /* RRPC_H_ */
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