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 = line->emeta;
29 struct pblk_w_ctx *w_ctx;
30 __le64 *lba_list = emeta_to_lbas(pblk, emeta->buf);
31 u64 paddr;
32 int nr_secs = pblk->min_write_pgs;
33 int i;
34
35 paddr = pblk_alloc_page(pblk, line, nr_secs);
36
37 for (i = 0; i < nr_secs; i++, paddr++) {
38 /* ppa to be sent to the device */
39 ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
40
41 /* Write context for target bio completion on write buffer. Note
42 * that the write buffer is protected by the sync backpointer,
43 * and a single writer thread have access to each specific entry
44 * at a time. Thus, it is safe to modify the context for the
45 * entry we are setting up for submission without taking any
46 * lock or memory barrier.
47 */
48 if (i < valid_secs) {
49 kref_get(&line->ref);
50 w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
51 w_ctx->ppa = ppa_list[i];
52 meta_list[i].lba = cpu_to_le64(w_ctx->lba);
53 lba_list[paddr] = cpu_to_le64(w_ctx->lba);
54 line->nr_valid_lbas++;
55 } else {
56 __le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
57
58 lba_list[paddr] = meta_list[i].lba = addr_empty;
59 __pblk_map_invalidate(pblk, line, paddr);
60 }
61 }
62
63 if (pblk_line_is_full(line)) {
64 struct pblk_line *prev_line = line;
65
66 pblk_line_replace_data(pblk);
67 pblk_line_close_meta(pblk, prev_line);
68 }
69
70 pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
71}
72
73void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
74 unsigned long *lun_bitmap, unsigned int valid_secs,
75 unsigned int off)
76{
77 struct pblk_sec_meta *meta_list = rqd->meta_list;
78 unsigned int map_secs;
79 int min = pblk->min_write_pgs;
80 int i;
81
82 for (i = off; i < rqd->nr_ppas; i += min) {
83 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
84 pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
85 lun_bitmap, &meta_list[i], map_secs);
86 }
87}
88
89/* only if erase_ppa is set, acquire erase semaphore */
90void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
91 unsigned int sentry, unsigned long *lun_bitmap,
92 unsigned int valid_secs, struct ppa_addr *erase_ppa)
93{
94 struct nvm_tgt_dev *dev = pblk->dev;
95 struct nvm_geo *geo = &dev->geo;
96 struct pblk_line_meta *lm = &pblk->lm;
97 struct pblk_sec_meta *meta_list = rqd->meta_list;
98 struct pblk_line *e_line, *d_line;
99 unsigned int map_secs;
100 int min = pblk->min_write_pgs;
101 int i, erase_lun;
102
103 for (i = 0; i < rqd->nr_ppas; i += min) {
104 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
105 pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
106 lun_bitmap, &meta_list[i], map_secs);
107
108 erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
109
110 /* line can change after page map. We might also be writing the
111 * last line.
112 */
113 e_line = pblk_line_get_erase(pblk);
114 if (!e_line)
115 return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
116 valid_secs, i + min);
117
118 spin_lock(&e_line->lock);
119 if (!test_bit(erase_lun, e_line->erase_bitmap)) {
120 set_bit(erase_lun, e_line->erase_bitmap);
121 atomic_dec(&e_line->left_eblks);
122
123 *erase_ppa = rqd->ppa_list[i];
124 erase_ppa->g.blk = e_line->id;
125
126 spin_unlock(&e_line->lock);
127
128 /* Avoid evaluating e_line->left_eblks */
129 return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
130 valid_secs, i + min);
131 }
132 spin_unlock(&e_line->lock);
133 }
134
135 d_line = pblk_line_get_data(pblk);
136
137 /* line can change after page map. We might also be writing the
138 * last line.
139 */
140 e_line = pblk_line_get_erase(pblk);
141 if (!e_line)
142 return;
143
144 /* Erase blocks that are bad in this line but might not be in next */
145 if (unlikely(ppa_empty(*erase_ppa)) &&
146 bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
147 int bit = -1;
148
149retry:
150 bit = find_next_bit(d_line->blk_bitmap,
151 lm->blk_per_line, bit + 1);
152 if (bit >= lm->blk_per_line)
153 return;
154
155 spin_lock(&e_line->lock);
156 if (test_bit(bit, e_line->erase_bitmap)) {
157 spin_unlock(&e_line->lock);
158 goto retry;
159 }
160 spin_unlock(&e_line->lock);
161
162 set_bit(bit, e_line->erase_bitmap);
163 atomic_dec(&e_line->left_eblks);
164 *erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
165 erase_ppa->g.blk = e_line->id;
166 }
167}