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;
51 struct rrpc_addr *addr;
56 struct nvm_block *parent;
57 struct rrpc_lun *rlun;
58 struct list_head prio;
60 #define MAX_INVALID_PAGES_STORAGE 8
61 /* Bitmap for invalid page intries */
62 unsigned long invalid_pages[MAX_INVALID_PAGES_STORAGE];
63 /* points to the next writable page within a block */
64 unsigned int next_page;
65 /* number of pages that are invalid, wrt host page size */
66 unsigned int nr_invalid_pages;
69 atomic_t data_cmnt_size; /* data pages committed to stable storage */
74 struct nvm_lun *parent;
75 struct rrpc_block *cur, *gc_cur;
76 struct rrpc_block *blocks; /* Reference to block allocation */
78 struct list_head prio_list; /* Blocks that may be GC'ed */
80 struct work_struct ws_gc;
86 /* instance must be kept in top to resolve rrpc in unprep */
87 struct nvm_tgt_instance instance;
92 sector_t soffset; /* logical sector offset */
93 u64 poffset; /* physical page offset */
97 struct rrpc_lun *luns;
99 /* calculated values */
100 unsigned long long nr_sects;
101 unsigned long total_blocks;
103 /* Write strategy variables. Move these into each for structure for each
106 atomic_t next_lun; /* Whenever a page is written, this is updated
107 * to point to the next write lun
111 struct bio_list requeue_bios;
112 struct work_struct ws_requeue;
114 /* Simple translation map of logical addresses to physical addresses.
115 * The logical addresses is known by the host system, while the physical
116 * addresses are used when writing to the disk block device.
118 struct rrpc_addr *trans_map;
119 /* also store a reverse map for garbage collection */
120 struct rrpc_rev_addr *rev_trans_map;
123 struct rrpc_inflight inflights;
125 mempool_t *addr_pool;
126 mempool_t *page_pool;
130 struct timer_list gc_timer;
131 struct workqueue_struct *krqd_wq;
132 struct workqueue_struct *kgc_wq;
135 struct rrpc_block_gc {
137 struct rrpc_block *rblk;
138 struct work_struct ws_gc;
141 /* Logical to physical mapping */
144 struct rrpc_block *rblk;
147 /* Physical to logical mapping */
148 struct rrpc_rev_addr {
152 static inline struct rrpc_block *rrpc_get_rblk(struct rrpc_lun *rlun,
155 struct rrpc *rrpc = rlun->rrpc;
156 int lun_blk = blk_id % rrpc->dev->blks_per_lun;
158 return &rlun->blocks[lun_blk];
161 static inline sector_t rrpc_get_laddr(struct bio *bio)
163 return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
166 static inline unsigned int rrpc_get_pages(struct bio *bio)
168 return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
171 static inline sector_t rrpc_get_sector(sector_t laddr)
173 return laddr * NR_PHY_IN_LOG;
176 static inline int request_intersects(struct rrpc_inflight_rq *r,
177 sector_t laddr_start, sector_t laddr_end)
179 return (laddr_end >= r->l_start) && (laddr_start <= r->l_end);
182 static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
183 unsigned int pages, struct rrpc_inflight_rq *r)
185 sector_t laddr_end = laddr + pages - 1;
186 struct rrpc_inflight_rq *rtmp;
188 WARN_ON(irqs_disabled());
190 spin_lock_irq(&rrpc->inflights.lock);
191 list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
192 if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
193 /* existing, overlapping request, come back later */
194 spin_unlock_irq(&rrpc->inflights.lock);
200 r->l_end = laddr_end;
202 list_add_tail(&r->list, &rrpc->inflights.reqs);
203 spin_unlock_irq(&rrpc->inflights.lock);
207 static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
209 struct rrpc_inflight_rq *r)
211 BUG_ON((laddr + pages) > rrpc->nr_sects);
213 return __rrpc_lock_laddr(rrpc, laddr, pages, r);
216 static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd)
218 struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
220 return &rrqd->inflight_rq;
223 static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio,
226 sector_t laddr = rrpc_get_laddr(bio);
227 unsigned int pages = rrpc_get_pages(bio);
228 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
230 return rrpc_lock_laddr(rrpc, laddr, pages, r);
233 static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
234 struct rrpc_inflight_rq *r)
238 spin_lock_irqsave(&rrpc->inflights.lock, flags);
239 list_del_init(&r->list);
240 spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
243 static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd)
245 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
246 uint8_t pages = rqd->nr_ppas;
248 BUG_ON((r->l_start + pages) > rrpc->nr_sects);
250 rrpc_unlock_laddr(rrpc, r);