summaryrefslogtreecommitdiff
path: root/drivers/lightnvm/pblk-map.c
blob: 20dbaa89c9dfe3e4837e7d64acecaea4a0ba616e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/*
 * Copyright (C) 2016 CNEX Labs
 * Initial release: Javier Gonzalez <javier@cnexlabs.com>
 *                  Matias Bjorling <matias@cnexlabs.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * pblk-map.c - pblk's lba-ppa mapping strategy
 *
 */

#include "pblk.h"

static void 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)
{
	struct pblk_line *line = pblk_line_get_data(pblk);
	struct pblk_emeta *emeta;
	struct pblk_w_ctx *w_ctx;
	__le64 *lba_list;
	u64 paddr;
	int nr_secs = pblk->min_write_pgs;
	int i;

	if (pblk_line_is_full(line)) {
		struct pblk_line *prev_line = line;

		line = pblk_line_replace_data(pblk);
		pblk_line_close_meta(pblk, prev_line);
	}

	emeta = line->emeta;
	lba_list = emeta_to_lbas(pblk, emeta->buf);

	paddr = pblk_alloc_page(pblk, line, nr_secs);

	for (i = 0; i < nr_secs; i++, paddr++) {
		__le64 addr_empty = cpu_to_le64(ADDR_EMPTY);

		/* ppa to be sent to the device */
		ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);

		/* Write context for target bio completion on write buffer. Note
		 * that the write buffer is protected by the sync backpointer,
		 * and a single writer thread have access to each specific entry
		 * at a time. Thus, it is safe to modify the context for the
		 * entry we are setting up for submission without taking any
		 * lock or memory barrier.
		 */
		if (i < valid_secs) {
			kref_get(&line->ref);
			w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
			w_ctx->ppa = ppa_list[i];
			meta_list[i].lba = cpu_to_le64(w_ctx->lba);
			lba_list[paddr] = cpu_to_le64(w_ctx->lba);
			if (lba_list[paddr] != addr_empty)
				line->nr_valid_lbas++;
			else
				atomic64_inc(&pblk->pad_wa);
		} else {
			lba_list[paddr] = meta_list[i].lba = addr_empty;
			__pblk_map_invalidate(pblk, line, paddr);
		}
	}

	pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
}

void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
		 unsigned long *lun_bitmap, unsigned int valid_secs,
		 unsigned int off)
{
	struct pblk_sec_meta *meta_list = rqd->meta_list;
	unsigned int map_secs;
	int min = pblk->min_write_pgs;
	int i;

	for (i = off; i < rqd->nr_ppas; i += min) {
		map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
		pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
					lun_bitmap, &meta_list[i], map_secs);
	}
}

/* only if erase_ppa is set, acquire erase semaphore */
void 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)
{
	struct nvm_tgt_dev *dev = pblk->dev;
	struct nvm_geo *geo = &dev->geo;
	struct pblk_line_meta *lm = &pblk->lm;
	struct pblk_sec_meta *meta_list = rqd->meta_list;
	struct pblk_line *e_line, *d_line;
	unsigned int map_secs;
	int min = pblk->min_write_pgs;
	int i, erase_lun;

	for (i = 0; i < rqd->nr_ppas; i += min) {
		map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
		pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
					lun_bitmap, &meta_list[i], map_secs);

		erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);

		/* line can change after page map. We might also be writing the
		 * last line.
		 */
		e_line = pblk_line_get_erase(pblk);
		if (!e_line)
			return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
							valid_secs, i + min);

		spin_lock(&e_line->lock);
		if (!test_bit(erase_lun, e_line->erase_bitmap)) {
			set_bit(erase_lun, e_line->erase_bitmap);
			atomic_dec(&e_line->left_eblks);

			*erase_ppa = rqd->ppa_list[i];
			erase_ppa->a.blk = e_line->id;

			spin_unlock(&e_line->lock);

			/* Avoid evaluating e_line->left_eblks */
			return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
							valid_secs, i + min);
		}
		spin_unlock(&e_line->lock);
	}

	d_line = pblk_line_get_data(pblk);

	/* line can change after page map. We might also be writing the
	 * last line.
	 */
	e_line = pblk_line_get_erase(pblk);
	if (!e_line)
		return;

	/* Erase blocks that are bad in this line but might not be in next */
	if (unlikely(pblk_ppa_empty(*erase_ppa)) &&
			bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
		int bit = -1;

retry:
		bit = find_next_bit(d_line->blk_bitmap,
						lm->blk_per_line, bit + 1);
		if (bit >= lm->blk_per_line)
			return;

		spin_lock(&e_line->lock);
		if (test_bit(bit, e_line->erase_bitmap)) {
			spin_unlock(&e_line->lock);
			goto retry;
		}
		spin_unlock(&e_line->lock);

		set_bit(bit, e_line->erase_bitmap);
		atomic_dec(&e_line->left_eblks);
		*erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
		erase_ppa->a.blk = e_line->id;
	}
}