1 /*
2 * Copyright (C) 2016 CNEX Labs
3 * Initial release: Javier Gonzalez <javier@cnexlabs.com>
4 * Matias Bjorling <matias@cnexlabs.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * pblk-map.c - pblk's lba-ppa mapping strategy
16 *
17 */
18
19 #include "pblk.h"
20
pblk_map_page_data(struct pblk * pblk,unsigned int sentry,struct ppa_addr * ppa_list,unsigned long * lun_bitmap,struct pblk_sec_meta * meta_list,unsigned int valid_secs)21 static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
22 struct ppa_addr *ppa_list,
23 unsigned long *lun_bitmap,
24 struct pblk_sec_meta *meta_list,
25 unsigned int valid_secs)
26 {
27 struct pblk_line *line = pblk_line_get_data(pblk);
28 struct pblk_emeta *emeta;
29 struct pblk_w_ctx *w_ctx;
30 __le64 *lba_list;
31 u64 paddr;
32 int nr_secs = pblk->min_write_pgs;
33 int i;
34
35 if (pblk_line_is_full(line)) {
36 struct pblk_line *prev_line = line;
37
38 /* If we cannot allocate a new line, make sure to store metadata
39 * on current line and then fail
40 */
41 line = pblk_line_replace_data(pblk);
42 pblk_line_close_meta(pblk, prev_line);
43
44 if (!line)
45 return -EINTR;
46 }
47
48 emeta = line->emeta;
49 lba_list = emeta_to_lbas(pblk, emeta->buf);
50
51 paddr = pblk_alloc_page(pblk, line, nr_secs);
52
53 for (i = 0; i < nr_secs; i++, paddr++) {
54 __le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
55
56 /* ppa to be sent to the device */
57 ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
58
59 /* Write context for target bio completion on write buffer. Note
60 * that the write buffer is protected by the sync backpointer,
61 * and a single writer thread have access to each specific entry
62 * at a time. Thus, it is safe to modify the context for the
63 * entry we are setting up for submission without taking any
64 * lock or memory barrier.
65 */
66 if (i < valid_secs) {
67 kref_get(&line->ref);
68 w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
69 w_ctx->ppa = ppa_list[i];
70 meta_list[i].lba = cpu_to_le64(w_ctx->lba);
71 lba_list[paddr] = cpu_to_le64(w_ctx->lba);
72 if (lba_list[paddr] != addr_empty)
73 line->nr_valid_lbas++;
74 else
75 atomic64_inc(&pblk->pad_wa);
76 } else {
77 lba_list[paddr] = meta_list[i].lba = addr_empty;
78 __pblk_map_invalidate(pblk, line, paddr);
79 }
80 }
81
82 pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
83 return 0;
84 }
85
pblk_map_rq(struct pblk * pblk,struct nvm_rq * rqd,unsigned int sentry,unsigned long * lun_bitmap,unsigned int valid_secs,unsigned int off)86 void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
87 unsigned long *lun_bitmap, unsigned int valid_secs,
88 unsigned int off)
89 {
90 struct pblk_sec_meta *meta_list = rqd->meta_list;
91 unsigned int map_secs;
92 int min = pblk->min_write_pgs;
93 int i;
94
95 for (i = off; i < rqd->nr_ppas; i += min) {
96 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
97 if (pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
98 lun_bitmap, &meta_list[i], map_secs)) {
99 bio_put(rqd->bio);
100 pblk_free_rqd(pblk, rqd, PBLK_WRITE);
101 pblk_pipeline_stop(pblk);
102 }
103 }
104 }
105
106 /* only if erase_ppa is set, acquire erase semaphore */
pblk_map_erase_rq(struct pblk * pblk,struct nvm_rq * rqd,unsigned int sentry,unsigned long * lun_bitmap,unsigned int valid_secs,struct ppa_addr * erase_ppa)107 void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
108 unsigned int sentry, unsigned long *lun_bitmap,
109 unsigned int valid_secs, struct ppa_addr *erase_ppa)
110 {
111 struct nvm_tgt_dev *dev = pblk->dev;
112 struct nvm_geo *geo = &dev->geo;
113 struct pblk_line_meta *lm = &pblk->lm;
114 struct pblk_sec_meta *meta_list = rqd->meta_list;
115 struct pblk_line *e_line, *d_line;
116 unsigned int map_secs;
117 int min = pblk->min_write_pgs;
118 int i, erase_lun;
119
120 for (i = 0; i < rqd->nr_ppas; i += min) {
121 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
122 if (pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
123 lun_bitmap, &meta_list[i], map_secs)) {
124 bio_put(rqd->bio);
125 pblk_free_rqd(pblk, rqd, PBLK_WRITE);
126 pblk_pipeline_stop(pblk);
127 }
128
129 erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
130
131 /* line can change after page map. We might also be writing the
132 * last line.
133 */
134 e_line = pblk_line_get_erase(pblk);
135 if (!e_line)
136 return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
137 valid_secs, i + min);
138
139 spin_lock(&e_line->lock);
140 if (!test_bit(erase_lun, e_line->erase_bitmap)) {
141 set_bit(erase_lun, e_line->erase_bitmap);
142 atomic_dec(&e_line->left_eblks);
143
144 *erase_ppa = rqd->ppa_list[i];
145 erase_ppa->a.blk = e_line->id;
146
147 spin_unlock(&e_line->lock);
148
149 /* Avoid evaluating e_line->left_eblks */
150 return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
151 valid_secs, i + min);
152 }
153 spin_unlock(&e_line->lock);
154 }
155
156 d_line = pblk_line_get_data(pblk);
157
158 /* line can change after page map. We might also be writing the
159 * last line.
160 */
161 e_line = pblk_line_get_erase(pblk);
162 if (!e_line)
163 return;
164
165 /* Erase blocks that are bad in this line but might not be in next */
166 if (unlikely(pblk_ppa_empty(*erase_ppa)) &&
167 bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
168 int bit = -1;
169
170 retry:
171 bit = find_next_bit(d_line->blk_bitmap,
172 lm->blk_per_line, bit + 1);
173 if (bit >= lm->blk_per_line)
174 return;
175
176 spin_lock(&e_line->lock);
177 if (test_bit(bit, e_line->erase_bitmap)) {
178 spin_unlock(&e_line->lock);
179 goto retry;
180 }
181 spin_unlock(&e_line->lock);
182
183 set_bit(bit, e_line->erase_bitmap);
184 atomic_dec(&e_line->left_eblks);
185 *erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
186 erase_ppa->a.blk = e_line->id;
187 }
188 }
189