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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 MB |
58 | struct list_head prio; |
59 | ||
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; | |
67 | ||
68 | spinlock_t lock; | |
69 | atomic_t data_cmnt_size; /* data pages committed to stable storage */ | |
70 | }; | |
71 | ||
72 | struct rrpc_lun { | |
73 | struct rrpc *rrpc; | |
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; | |
79 | ||
80 | spinlock_t lock; | |
81 | }; | |
82 | ||
83 | struct rrpc { | |
84 | /* instance must be kept in top to resolve rrpc in unprep */ | |
85 | struct nvm_tgt_instance instance; | |
86 | ||
87 | struct nvm_dev *dev; | |
88 | struct gendisk *disk; | |
89 | ||
b7ceb7d5 | 90 | u64 poffset; /* physical page offset */ |
ae1519ec MB |
91 | int lun_offset; |
92 | ||
93 | int nr_luns; | |
94 | struct rrpc_lun *luns; | |
95 | ||
96 | /* calculated values */ | |
97 | unsigned long long nr_pages; | |
98 | unsigned long total_blocks; | |
99 | ||
100 | /* Write strategy variables. Move these into each for structure for each | |
101 | * strategy | |
102 | */ | |
103 | atomic_t next_lun; /* Whenever a page is written, this is updated | |
104 | * to point to the next write lun | |
105 | */ | |
106 | ||
107 | spinlock_t bio_lock; | |
108 | struct bio_list requeue_bios; | |
109 | struct work_struct ws_requeue; | |
110 | ||
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. | |
114 | */ | |
115 | struct rrpc_addr *trans_map; | |
116 | /* also store a reverse map for garbage collection */ | |
117 | struct rrpc_rev_addr *rev_trans_map; | |
118 | spinlock_t rev_lock; | |
119 | ||
120 | struct rrpc_inflight inflights; | |
121 | ||
122 | mempool_t *addr_pool; | |
123 | mempool_t *page_pool; | |
124 | mempool_t *gcb_pool; | |
125 | mempool_t *rq_pool; | |
126 | ||
127 | struct timer_list gc_timer; | |
128 | struct workqueue_struct *krqd_wq; | |
129 | struct workqueue_struct *kgc_wq; | |
130 | }; | |
131 | ||
132 | struct rrpc_block_gc { | |
133 | struct rrpc *rrpc; | |
134 | struct rrpc_block *rblk; | |
135 | struct work_struct ws_gc; | |
136 | }; | |
137 | ||
138 | /* Logical to physical mapping */ | |
139 | struct rrpc_addr { | |
b7ceb7d5 | 140 | u64 addr; |
ae1519ec MB |
141 | struct rrpc_block *rblk; |
142 | }; | |
143 | ||
144 | /* Physical to logical mapping */ | |
145 | struct rrpc_rev_addr { | |
b7ceb7d5 | 146 | u64 addr; |
ae1519ec MB |
147 | }; |
148 | ||
149 | static inline sector_t rrpc_get_laddr(struct bio *bio) | |
150 | { | |
151 | return bio->bi_iter.bi_sector / NR_PHY_IN_LOG; | |
152 | } | |
153 | ||
154 | static inline unsigned int rrpc_get_pages(struct bio *bio) | |
155 | { | |
156 | return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE; | |
157 | } | |
158 | ||
159 | static inline sector_t rrpc_get_sector(sector_t laddr) | |
160 | { | |
161 | return laddr * NR_PHY_IN_LOG; | |
162 | } | |
163 | ||
164 | static inline int request_intersects(struct rrpc_inflight_rq *r, | |
165 | sector_t laddr_start, sector_t laddr_end) | |
166 | { | |
167 | return (laddr_end >= r->l_start && laddr_end <= r->l_end) && | |
168 | (laddr_start >= r->l_start && laddr_start <= r->l_end); | |
169 | } | |
170 | ||
171 | static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr, | |
172 | unsigned pages, struct rrpc_inflight_rq *r) | |
173 | { | |
174 | sector_t laddr_end = laddr + pages - 1; | |
175 | struct rrpc_inflight_rq *rtmp; | |
176 | ||
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); | |
182 | return 1; | |
183 | } | |
184 | } | |
185 | ||
186 | r->l_start = laddr; | |
187 | r->l_end = laddr_end; | |
188 | ||
189 | list_add_tail(&r->list, &rrpc->inflights.reqs); | |
190 | spin_unlock_irq(&rrpc->inflights.lock); | |
191 | return 0; | |
192 | } | |
193 | ||
194 | static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr, | |
195 | unsigned pages, | |
196 | struct rrpc_inflight_rq *r) | |
197 | { | |
198 | BUG_ON((laddr + pages) > rrpc->nr_pages); | |
199 | ||
200 | return __rrpc_lock_laddr(rrpc, laddr, pages, r); | |
201 | } | |
202 | ||
203 | static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd) | |
204 | { | |
205 | struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd); | |
206 | ||
207 | return &rrqd->inflight_rq; | |
208 | } | |
209 | ||
210 | static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio, | |
211 | struct nvm_rq *rqd) | |
212 | { | |
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); | |
216 | ||
217 | return rrpc_lock_laddr(rrpc, laddr, pages, r); | |
218 | } | |
219 | ||
220 | static inline void rrpc_unlock_laddr(struct rrpc *rrpc, | |
221 | struct rrpc_inflight_rq *r) | |
222 | { | |
223 | unsigned long flags; | |
224 | ||
225 | spin_lock_irqsave(&rrpc->inflights.lock, flags); | |
226 | list_del_init(&r->list); | |
227 | spin_unlock_irqrestore(&rrpc->inflights.lock, flags); | |
228 | } | |
229 | ||
230 | static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd) | |
231 | { | |
232 | struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd); | |
233 | uint8_t pages = rqd->nr_pages; | |
234 | ||
235 | BUG_ON((r->l_start + pages) > rrpc->nr_pages); | |
236 | ||
237 | rrpc_unlock_laddr(rrpc, r); | |
238 | } | |
239 | ||
240 | #endif /* RRPC_H_ */ |