tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
21static void 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 line = pblk_line_replace_data(pblk);
39 pblk_line_close_meta(pblk, prev_line);
40 }
41
42 emeta = line->emeta;
43 lba_list = emeta_to_lbas(pblk, emeta->buf);
44
45 paddr = pblk_alloc_page(pblk, line, nr_secs);
46
47 for (i = 0; i < nr_secs; i++, paddr++) {
48 __le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
49
50 /* ppa to be sent to the device */
51 ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
52
53 /* Write context for target bio completion on write buffer. Note
54 * that the write buffer is protected by the sync backpointer,
55 * and a single writer thread have access to each specific entry
56 * at a time. Thus, it is safe to modify the context for the
57 * entry we are setting up for submission without taking any
58 * lock or memory barrier.
59 */
60 if (i < valid_secs) {
61 kref_get(&line->ref);
62 w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
63 w_ctx->ppa = ppa_list[i];
64 meta_list[i].lba = cpu_to_le64(w_ctx->lba);
65 lba_list[paddr] = cpu_to_le64(w_ctx->lba);
66 if (lba_list[paddr] != addr_empty)
67 line->nr_valid_lbas++;
68 } else {
69 lba_list[paddr] = meta_list[i].lba = addr_empty;
70 __pblk_map_invalidate(pblk, line, paddr);
71 }
72 }
73
74 pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
75}
76
77void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
78 unsigned long *lun_bitmap, unsigned int valid_secs,
79 unsigned int off)
80{
81 struct pblk_sec_meta *meta_list = rqd->meta_list;
82 unsigned int map_secs;
83 int min = pblk->min_write_pgs;
84 int i;
85
86 for (i = off; i < rqd->nr_ppas; i += min) {
87 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
88 pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
89 lun_bitmap, &meta_list[i], map_secs);
90 }
91}
92
93/* only if erase_ppa is set, acquire erase semaphore */
94void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
95 unsigned int sentry, unsigned long *lun_bitmap,
96 unsigned int valid_secs, struct ppa_addr *erase_ppa)
97{
98 struct nvm_tgt_dev *dev = pblk->dev;
99 struct nvm_geo *geo = &dev->geo;
100 struct pblk_line_meta *lm = &pblk->lm;
101 struct pblk_sec_meta *meta_list = rqd->meta_list;
102 struct pblk_line *e_line, *d_line;
103 unsigned int map_secs;
104 int min = pblk->min_write_pgs;
105 int i, erase_lun;
106
107 for (i = 0; i < rqd->nr_ppas; i += min) {
108 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
109 pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
110 lun_bitmap, &meta_list[i], map_secs);
111
112 erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
113
114 /* line can change after page map. We might also be writing the
115 * last line.
116 */
117 e_line = pblk_line_get_erase(pblk);
118 if (!e_line)
119 return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
120 valid_secs, i + min);
121
122 spin_lock(&e_line->lock);
123 if (!test_bit(erase_lun, e_line->erase_bitmap)) {
124 set_bit(erase_lun, e_line->erase_bitmap);
125 atomic_dec(&e_line->left_eblks);
126
127 *erase_ppa = rqd->ppa_list[i];
128 erase_ppa->g.blk = e_line->id;
129
130 spin_unlock(&e_line->lock);
131
132 /* Avoid evaluating e_line->left_eblks */
133 return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
134 valid_secs, i + min);
135 }
136 spin_unlock(&e_line->lock);
137 }
138
139 d_line = pblk_line_get_data(pblk);
140
141 /* line can change after page map. We might also be writing the
142 * last line.
143 */
144 e_line = pblk_line_get_erase(pblk);
145 if (!e_line)
146 return;
147
148 /* Erase blocks that are bad in this line but might not be in next */
149 if (unlikely(ppa_empty(*erase_ppa)) &&
150 bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
151 int bit = -1;
152
153retry:
154 bit = find_next_bit(d_line->blk_bitmap,
155 lm->blk_per_line, bit + 1);
156 if (bit >= lm->blk_per_line)
157 return;
158
159 spin_lock(&e_line->lock);
160 if (test_bit(bit, e_line->erase_bitmap)) {
161 spin_unlock(&e_line->lock);
162 goto retry;
163 }
164 spin_unlock(&e_line->lock);
165
166 set_bit(bit, e_line->erase_bitmap);
167 atomic_dec(&e_line->left_eblks);
168 *erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
169 erase_ppa->g.blk = e_line->id;
170 }
171}