2 * Copyright (C) 2015 IT University of Copenhagen
3 * Initial release: Matias Bjorling <m@bjorling.me>
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License version
7 * 2 as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
20 #include <linux/blkdev.h>
21 #include <linux/blk-mq.h>
22 #include <linux/bio.h>
23 #include <linux/module.h>
24 #include <linux/kthread.h>
25 #include <linux/vmalloc.h>
27 #include <linux/lightnvm.h>
29 /* Run only GC if less than 1/X blocks are free */
30 #define GC_LIMIT_INVERSE 10
31 #define GC_TIME_SECS 100
33 #define RRPC_SECTOR (512)
34 #define RRPC_EXPOSED_PAGE_SIZE (4096)
36 #define NR_PHY_IN_LOG (RRPC_EXPOSED_PAGE_SIZE / RRPC_SECTOR)
38 struct rrpc_inflight {
39 struct list_head reqs;
43 struct rrpc_inflight_rq {
44 struct list_head list;
50 struct rrpc_inflight_rq inflight_rq;
55 int id; /* id inside of LUN */
56 struct rrpc_lun *rlun;
58 struct list_head prio; /* LUN CG list */
59 struct list_head list; /* LUN free, used, bb list */
61 #define MAX_INVALID_PAGES_STORAGE 8
62 /* Bitmap for invalid page intries */
63 unsigned long invalid_pages[MAX_INVALID_PAGES_STORAGE];
64 /* points to the next writable page within a block */
65 unsigned int next_page;
66 /* number of pages that are invalid, wrt host page size */
67 unsigned int nr_invalid_pages;
72 atomic_t data_cmnt_size; /* data pages committed to stable storage */
81 struct rrpc_block *cur, *gc_cur;
82 struct rrpc_block *blocks; /* Reference to block allocation */
84 struct list_head prio_list; /* Blocks that may be GC'ed */
85 struct list_head wblk_list; /* Queued blocks to be written to */
88 struct list_head used_list; /* In-use blocks */
89 struct list_head free_list; /* Not used blocks i.e. released
92 struct list_head bb_list; /* Bad blocks. Mutually exclusive with
93 * free_list and used_list
95 unsigned int nr_free_blocks; /* Number of unused blocks */
97 struct work_struct ws_gc;
105 /* instance must be kept in top to resolve rrpc in unprep */
106 struct nvm_tgt_instance instance;
108 struct nvm_tgt_dev *dev;
109 struct gendisk *disk;
111 sector_t soffset; /* logical sector offset */
114 struct rrpc_lun *luns;
116 /* calculated values */
117 unsigned long long nr_sects;
119 /* Write strategy variables. Move these into each for structure for each
122 atomic_t next_lun; /* Whenever a page is written, this is updated
123 * to point to the next write lun
127 struct bio_list requeue_bios;
128 struct work_struct ws_requeue;
130 /* Simple translation map of logical addresses to physical addresses.
131 * The logical addresses is known by the host system, while the physical
132 * addresses are used when writing to the disk block device.
134 struct rrpc_addr *trans_map;
135 /* also store a reverse map for garbage collection */
136 struct rrpc_rev_addr *rev_trans_map;
139 struct rrpc_inflight inflights;
141 mempool_t *addr_pool;
142 mempool_t *page_pool;
146 struct timer_list gc_timer;
147 struct workqueue_struct *krqd_wq;
148 struct workqueue_struct *kgc_wq;
151 struct rrpc_block_gc {
153 struct rrpc_block *rblk;
154 struct work_struct ws_gc;
157 /* Logical to physical mapping */
160 struct rrpc_block *rblk;
163 /* Physical to logical mapping */
164 struct rrpc_rev_addr {
168 static inline struct ppa_addr rrpc_linear_to_generic_addr(struct nvm_geo *geo,
173 sector_t ppa = r.ppa;
177 div_u64_rem(ppa, geo->sec_per_pg, &secs);
180 sector_div(ppa, geo->sec_per_pg);
181 div_u64_rem(ppa, geo->pgs_per_blk, &pgs);
187 static inline struct ppa_addr rrpc_recov_addr(struct nvm_tgt_dev *dev, u64 pba)
189 return linear_to_generic_addr(&dev->geo, pba);
192 static inline u64 rrpc_blk_to_ppa(struct rrpc *rrpc, struct rrpc_block *rblk)
194 struct nvm_tgt_dev *dev = rrpc->dev;
195 struct nvm_geo *geo = &dev->geo;
196 struct rrpc_lun *rlun = rblk->rlun;
198 return (rlun->id * geo->sec_per_lun) + (rblk->id * geo->sec_per_blk);
201 static inline sector_t rrpc_get_laddr(struct bio *bio)
203 return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
206 static inline unsigned int rrpc_get_pages(struct bio *bio)
208 return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
211 static inline sector_t rrpc_get_sector(sector_t laddr)
213 return laddr * NR_PHY_IN_LOG;
216 static inline int request_intersects(struct rrpc_inflight_rq *r,
217 sector_t laddr_start, sector_t laddr_end)
219 return (laddr_end >= r->l_start) && (laddr_start <= r->l_end);
222 static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
223 unsigned int pages, struct rrpc_inflight_rq *r)
225 sector_t laddr_end = laddr + pages - 1;
226 struct rrpc_inflight_rq *rtmp;
228 WARN_ON(irqs_disabled());
230 spin_lock_irq(&rrpc->inflights.lock);
231 list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
232 if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
233 /* existing, overlapping request, come back later */
234 spin_unlock_irq(&rrpc->inflights.lock);
240 r->l_end = laddr_end;
242 list_add_tail(&r->list, &rrpc->inflights.reqs);
243 spin_unlock_irq(&rrpc->inflights.lock);
247 static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
249 struct rrpc_inflight_rq *r)
251 BUG_ON((laddr + pages) > rrpc->nr_sects);
253 return __rrpc_lock_laddr(rrpc, laddr, pages, r);
256 static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd)
258 struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
260 return &rrqd->inflight_rq;
263 static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio,
266 sector_t laddr = rrpc_get_laddr(bio);
267 unsigned int pages = rrpc_get_pages(bio);
268 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
270 return rrpc_lock_laddr(rrpc, laddr, pages, r);
273 static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
274 struct rrpc_inflight_rq *r)
278 spin_lock_irqsave(&rrpc->inflights.lock, flags);
279 list_del_init(&r->list);
280 spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
283 static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd)
285 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
286 uint8_t pages = rqd->nr_ppas;
288 BUG_ON((r->l_start + pages) > rrpc->nr_sects);
290 rrpc_unlock_laddr(rrpc, r);