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1 | /* |
2 | * Copyright (C) 2015 IT University of Copenhagen | |
3 | * Initial release: Matias Bjorling <m@bjorling.me> | |
4 | * | |
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. | |
8 | * | |
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. | |
13 | * | |
14 | * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs. | |
15 | */ | |
16 | ||
17 | #ifndef RRPC_H_ | |
18 | #define RRPC_H_ | |
19 | ||
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> | |
26 | ||
27 | #include <linux/lightnvm.h> | |
28 | ||
29 | /* Run only GC if less than 1/X blocks are free */ | |
30 | #define GC_LIMIT_INVERSE 10 | |
31 | #define GC_TIME_SECS 100 | |
32 | ||
33 | #define RRPC_SECTOR (512) | |
34 | #define RRPC_EXPOSED_PAGE_SIZE (4096) | |
35 | ||
36 | #define NR_PHY_IN_LOG (RRPC_EXPOSED_PAGE_SIZE / RRPC_SECTOR) | |
37 | ||
38 | struct rrpc_inflight { | |
39 | struct list_head reqs; | |
40 | spinlock_t lock; | |
41 | }; | |
42 | ||
43 | struct rrpc_inflight_rq { | |
44 | struct list_head list; | |
45 | sector_t l_start; | |
46 | sector_t l_end; | |
47 | }; | |
48 | ||
49 | struct rrpc_rq { | |
50 | struct rrpc_inflight_rq inflight_rq; | |
51 | struct rrpc_addr *addr; | |
52 | unsigned long flags; | |
53 | }; | |
54 | ||
55 | struct rrpc_block { | |
56 | struct nvm_block *parent; | |
d7a64d27 | 57 | struct rrpc_lun *rlun; |
ae1519ec | 58 | struct list_head prio; |
ff0e498b | 59 | struct list_head list; |
ae1519ec MB |
60 | |
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; | |
68 | ||
69 | spinlock_t lock; | |
70 | atomic_t data_cmnt_size; /* data pages committed to stable storage */ | |
71 | }; | |
72 | ||
73 | struct rrpc_lun { | |
74 | struct rrpc *rrpc; | |
75 | struct nvm_lun *parent; | |
76 | struct rrpc_block *cur, *gc_cur; | |
77 | struct rrpc_block *blocks; /* Reference to block allocation */ | |
ff0e498b JG |
78 | |
79 | struct list_head prio_list; /* Blocks that may be GC'ed */ | |
80 | struct list_head open_list; /* In-use open blocks. These are blocks | |
81 | * that can be both written to and read | |
82 | * from | |
83 | */ | |
84 | struct list_head closed_list; /* In-use closed blocks. These are | |
85 | * blocks that can _only_ be read from | |
86 | */ | |
87 | ||
ae1519ec MB |
88 | struct work_struct ws_gc; |
89 | ||
90 | spinlock_t lock; | |
91 | }; | |
92 | ||
93 | struct rrpc { | |
94 | /* instance must be kept in top to resolve rrpc in unprep */ | |
95 | struct nvm_tgt_instance instance; | |
96 | ||
97 | struct nvm_dev *dev; | |
98 | struct gendisk *disk; | |
99 | ||
4c9dacb8 | 100 | sector_t soffset; /* logical sector offset */ |
b7ceb7d5 | 101 | u64 poffset; /* physical page offset */ |
ae1519ec MB |
102 | int lun_offset; |
103 | ||
104 | int nr_luns; | |
105 | struct rrpc_lun *luns; | |
106 | ||
107 | /* calculated values */ | |
4ece44af | 108 | unsigned long long nr_sects; |
ae1519ec MB |
109 | unsigned long total_blocks; |
110 | ||
111 | /* Write strategy variables. Move these into each for structure for each | |
112 | * strategy | |
113 | */ | |
114 | atomic_t next_lun; /* Whenever a page is written, this is updated | |
115 | * to point to the next write lun | |
116 | */ | |
117 | ||
118 | spinlock_t bio_lock; | |
119 | struct bio_list requeue_bios; | |
120 | struct work_struct ws_requeue; | |
121 | ||
122 | /* Simple translation map of logical addresses to physical addresses. | |
123 | * The logical addresses is known by the host system, while the physical | |
124 | * addresses are used when writing to the disk block device. | |
125 | */ | |
126 | struct rrpc_addr *trans_map; | |
127 | /* also store a reverse map for garbage collection */ | |
128 | struct rrpc_rev_addr *rev_trans_map; | |
129 | spinlock_t rev_lock; | |
130 | ||
131 | struct rrpc_inflight inflights; | |
132 | ||
133 | mempool_t *addr_pool; | |
134 | mempool_t *page_pool; | |
135 | mempool_t *gcb_pool; | |
136 | mempool_t *rq_pool; | |
137 | ||
138 | struct timer_list gc_timer; | |
139 | struct workqueue_struct *krqd_wq; | |
140 | struct workqueue_struct *kgc_wq; | |
141 | }; | |
142 | ||
143 | struct rrpc_block_gc { | |
144 | struct rrpc *rrpc; | |
145 | struct rrpc_block *rblk; | |
146 | struct work_struct ws_gc; | |
147 | }; | |
148 | ||
149 | /* Logical to physical mapping */ | |
150 | struct rrpc_addr { | |
b7ceb7d5 | 151 | u64 addr; |
ae1519ec MB |
152 | struct rrpc_block *rblk; |
153 | }; | |
154 | ||
155 | /* Physical to logical mapping */ | |
156 | struct rrpc_rev_addr { | |
b7ceb7d5 | 157 | u64 addr; |
ae1519ec MB |
158 | }; |
159 | ||
afb18e0e JG |
160 | static inline struct rrpc_block *rrpc_get_rblk(struct rrpc_lun *rlun, |
161 | int blk_id) | |
162 | { | |
163 | struct rrpc *rrpc = rlun->rrpc; | |
164 | int lun_blk = blk_id % rrpc->dev->blks_per_lun; | |
165 | ||
166 | return &rlun->blocks[lun_blk]; | |
167 | } | |
168 | ||
ae1519ec MB |
169 | static inline sector_t rrpc_get_laddr(struct bio *bio) |
170 | { | |
171 | return bio->bi_iter.bi_sector / NR_PHY_IN_LOG; | |
172 | } | |
173 | ||
174 | static inline unsigned int rrpc_get_pages(struct bio *bio) | |
175 | { | |
176 | return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE; | |
177 | } | |
178 | ||
179 | static inline sector_t rrpc_get_sector(sector_t laddr) | |
180 | { | |
181 | return laddr * NR_PHY_IN_LOG; | |
182 | } | |
183 | ||
184 | static inline int request_intersects(struct rrpc_inflight_rq *r, | |
185 | sector_t laddr_start, sector_t laddr_end) | |
186 | { | |
3704e098 | 187 | return (laddr_end >= r->l_start) && (laddr_start <= r->l_end); |
ae1519ec MB |
188 | } |
189 | ||
190 | static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr, | |
191 | unsigned pages, struct rrpc_inflight_rq *r) | |
192 | { | |
193 | sector_t laddr_end = laddr + pages - 1; | |
194 | struct rrpc_inflight_rq *rtmp; | |
195 | ||
bba7f40a JG |
196 | WARN_ON(irqs_disabled()); |
197 | ||
ae1519ec MB |
198 | spin_lock_irq(&rrpc->inflights.lock); |
199 | list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) { | |
200 | if (unlikely(request_intersects(rtmp, laddr, laddr_end))) { | |
201 | /* existing, overlapping request, come back later */ | |
202 | spin_unlock_irq(&rrpc->inflights.lock); | |
203 | return 1; | |
204 | } | |
205 | } | |
206 | ||
207 | r->l_start = laddr; | |
208 | r->l_end = laddr_end; | |
209 | ||
210 | list_add_tail(&r->list, &rrpc->inflights.reqs); | |
211 | spin_unlock_irq(&rrpc->inflights.lock); | |
212 | return 0; | |
213 | } | |
214 | ||
215 | static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr, | |
216 | unsigned pages, | |
217 | struct rrpc_inflight_rq *r) | |
218 | { | |
4ece44af | 219 | BUG_ON((laddr + pages) > rrpc->nr_sects); |
ae1519ec MB |
220 | |
221 | return __rrpc_lock_laddr(rrpc, laddr, pages, r); | |
222 | } | |
223 | ||
224 | static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd) | |
225 | { | |
226 | struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd); | |
227 | ||
228 | return &rrqd->inflight_rq; | |
229 | } | |
230 | ||
231 | static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio, | |
232 | struct nvm_rq *rqd) | |
233 | { | |
234 | sector_t laddr = rrpc_get_laddr(bio); | |
235 | unsigned int pages = rrpc_get_pages(bio); | |
236 | struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd); | |
237 | ||
238 | return rrpc_lock_laddr(rrpc, laddr, pages, r); | |
239 | } | |
240 | ||
241 | static inline void rrpc_unlock_laddr(struct rrpc *rrpc, | |
242 | struct rrpc_inflight_rq *r) | |
243 | { | |
244 | unsigned long flags; | |
245 | ||
246 | spin_lock_irqsave(&rrpc->inflights.lock, flags); | |
247 | list_del_init(&r->list); | |
248 | spin_unlock_irqrestore(&rrpc->inflights.lock, flags); | |
249 | } | |
250 | ||
251 | static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd) | |
252 | { | |
253 | struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd); | |
254 | uint8_t pages = rqd->nr_pages; | |
255 | ||
4ece44af | 256 | BUG_ON((r->l_start + pages) > rrpc->nr_sects); |
ae1519ec MB |
257 | |
258 | rrpc_unlock_laddr(rrpc, r); | |
259 | } | |
260 | ||
261 | #endif /* RRPC_H_ */ |