Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
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linux
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
38struct rrpc_inflight {
39 struct list_head reqs;
40 spinlock_t lock;
41};
42
43struct rrpc_inflight_rq {
44 struct list_head list;
45 sector_t l_start;
46 sector_t l_end;
47};
48
49struct rrpc_rq {
50 struct rrpc_inflight_rq inflight_rq;
51 struct rrpc_addr *addr;
52 unsigned long flags;
53};
54
55struct rrpc_block {
56 struct nvm_block *parent;
57 struct rrpc_lun *rlun;
58 struct list_head prio;
59 struct list_head list;
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
73struct 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 */
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
88 struct work_struct ws_gc;
89
90 spinlock_t lock;
91};
92
93struct 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
100 sector_t soffset; /* logical sector offset */
101 u64 poffset; /* physical page offset */
102 int lun_offset;
103
104 int nr_luns;
105 struct rrpc_lun *luns;
106
107 /* calculated values */
108 unsigned long long nr_sects;
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
143struct 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 */
150struct rrpc_addr {
151 u64 addr;
152 struct rrpc_block *rblk;
153};
154
155/* Physical to logical mapping */
156struct rrpc_rev_addr {
157 u64 addr;
158};
159
160static 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
169static inline sector_t rrpc_get_laddr(struct bio *bio)
170{
171 return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
172}
173
174static inline unsigned int rrpc_get_pages(struct bio *bio)
175{
176 return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
177}
178
179static inline sector_t rrpc_get_sector(sector_t laddr)
180{
181 return laddr * NR_PHY_IN_LOG;
182}
183
184static inline int request_intersects(struct rrpc_inflight_rq *r,
185 sector_t laddr_start, sector_t laddr_end)
186{
187 return (laddr_end >= r->l_start) && (laddr_start <= r->l_end);
188}
189
190static 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
196 WARN_ON(irqs_disabled());
197
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
215static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
216 unsigned pages,
217 struct rrpc_inflight_rq *r)
218{
219 BUG_ON((laddr + pages) > rrpc->nr_sects);
220
221 return __rrpc_lock_laddr(rrpc, laddr, pages, r);
222}
223
224static 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
231static 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
241static 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
251static 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_ppas;
255
256 BUG_ON((r->l_start + pages) > rrpc->nr_sects);
257
258 rrpc_unlock_laddr(rrpc, r);
259}
260
261#endif /* RRPC_H_ */