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 */
77 struct list_head prio_list; /* Blocks that may be GC'ed */
78 struct work_struct ws_gc;
84 /* instance must be kept in top to resolve rrpc in unprep */
85 struct nvm_tgt_instance instance;
90 u64 poffset; /* physical page offset */
94 struct rrpc_lun *luns;
96 /* calculated values */
97 unsigned long long nr_pages;
98 unsigned long total_blocks;
100 /* Write strategy variables. Move these into each for structure for each
103 atomic_t next_lun; /* Whenever a page is written, this is updated
104 * to point to the next write lun
108 struct bio_list requeue_bios;
109 struct work_struct ws_requeue;
111 /* Simple translation map of logical addresses to physical addresses.
112 * The logical addresses is known by the host system, while the physical
113 * addresses are used when writing to the disk block device.
115 struct rrpc_addr *trans_map;
116 /* also store a reverse map for garbage collection */
117 struct rrpc_rev_addr *rev_trans_map;
120 struct rrpc_inflight inflights;
122 mempool_t *addr_pool;
123 mempool_t *page_pool;
127 struct timer_list gc_timer;
128 struct workqueue_struct *krqd_wq;
129 struct workqueue_struct *kgc_wq;
132 struct rrpc_block_gc {
134 struct rrpc_block *rblk;
135 struct work_struct ws_gc;
138 /* Logical to physical mapping */
141 struct rrpc_block *rblk;
144 /* Physical to logical mapping */
145 struct rrpc_rev_addr {
149 static inline sector_t rrpc_get_laddr(struct bio *bio)
151 return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
154 static inline unsigned int rrpc_get_pages(struct bio *bio)
156 return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
159 static inline sector_t rrpc_get_sector(sector_t laddr)
161 return laddr * NR_PHY_IN_LOG;
164 static inline int request_intersects(struct rrpc_inflight_rq *r,
165 sector_t laddr_start, sector_t laddr_end)
167 return (laddr_end >= r->l_start && laddr_end <= r->l_end) &&
168 (laddr_start >= r->l_start && laddr_start <= r->l_end);
171 static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
172 unsigned pages, struct rrpc_inflight_rq *r)
174 sector_t laddr_end = laddr + pages - 1;
175 struct rrpc_inflight_rq *rtmp;
177 spin_lock_irq(&rrpc->inflights.lock);
178 list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
179 if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
180 /* existing, overlapping request, come back later */
181 spin_unlock_irq(&rrpc->inflights.lock);
187 r->l_end = laddr_end;
189 list_add_tail(&r->list, &rrpc->inflights.reqs);
190 spin_unlock_irq(&rrpc->inflights.lock);
194 static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
196 struct rrpc_inflight_rq *r)
198 BUG_ON((laddr + pages) > rrpc->nr_pages);
200 return __rrpc_lock_laddr(rrpc, laddr, pages, r);
203 static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd)
205 struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
207 return &rrqd->inflight_rq;
210 static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio,
213 sector_t laddr = rrpc_get_laddr(bio);
214 unsigned int pages = rrpc_get_pages(bio);
215 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
217 return rrpc_lock_laddr(rrpc, laddr, pages, r);
220 static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
221 struct rrpc_inflight_rq *r)
225 spin_lock_irqsave(&rrpc->inflights.lock, flags);
226 list_del_init(&r->list);
227 spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
230 static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd)
232 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
233 uint8_t pages = rqd->nr_pages;
235 BUG_ON((r->l_start + pages) > rrpc->nr_pages);
237 rrpc_unlock_laddr(rrpc, r);