In prepartion of supporting RAIL, add the RAIL API.
Signed-off-by: Heiner Litz <hlitz@xxxxxxxx>
---
drivers/lightnvm/pblk-rail.c | 808 +++++++++++++++++++++++++++++++++++
drivers/lightnvm/pblk.h | 63 ++-
2 files changed, 870 insertions(+), 1 deletion(-)
create mode 100644 drivers/lightnvm/pblk-rail.c
diff --git a/drivers/lightnvm/pblk-rail.c b/drivers/lightnvm/pblk-rail.c
new file mode 100644
index 000000000000..a48ed31a0ba9
--- /dev/null
+++ b/drivers/lightnvm/pblk-rail.c
@@ -0,0 +1,808 @@
+/*
+ * Copyright (C) 2018 Heiner Litz
+ * Initial release: Heiner Litz <hlitz@xxxxxxxx>
+ *
+ * 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-rail.c - pblk's RAIL path
+ */
+
+#include "pblk.h"
+
+#define PBLK_RAIL_EMPTY ~0x0
+#define PBLK_RAIL_PARITY_WRITE 0x8000
+
+/* RAIL auxiliary functions */
+static unsigned int pblk_rail_nr_parity_luns(struct pblk *pblk)
+{
+ struct pblk_line_meta *lm = &pblk->lm;
+
+ return lm->blk_per_line / PBLK_RAIL_STRIDE_WIDTH;
+}
+
+static unsigned int pblk_rail_nr_data_luns(struct pblk *pblk)
+{
+ struct pblk_line_meta *lm = &pblk->lm;
+
+ return lm->blk_per_line - pblk_rail_nr_parity_luns(pblk);
+}
+
+static unsigned int pblk_rail_sec_per_stripe(struct pblk *pblk)
+{
+ struct pblk_line_meta *lm = &pblk->lm;
+
+ return lm->blk_per_line * pblk->min_write_pgs;
+}
+
+static unsigned int pblk_rail_psec_per_stripe(struct pblk *pblk)
+{
+ return pblk_rail_nr_parity_luns(pblk) * pblk->min_write_pgs;
+}
+
+static unsigned int pblk_rail_dsec_per_stripe(struct pblk *pblk)
+{
+ return pblk_rail_sec_per_stripe(pblk) - pblk_rail_psec_per_stripe(pblk);
+}
+
+static unsigned int pblk_rail_wrap_lun(struct pblk *pblk, unsigned int lun)
+{
+ struct pblk_line_meta *lm = &pblk->lm;
+
+ return (lun & (lm->blk_per_line - 1));
+}
+
+bool pblk_rail_meta_distance(struct pblk_line *data_line)
+{
+ return (data_line->meta_distance % PBLK_RAIL_STRIDE_WIDTH) == 0;
+}
+
+/* Notify readers that LUN is serving high latency operation */
+static void pblk_rail_notify_reader_down(struct pblk *pblk, int lun)
+{
+ WARN_ON(test_and_set_bit(lun, pblk->rail.busy_bitmap));
+ /* Make sure that busy bit is seen by reader before proceeding */
+ smp_mb__after_atomic();
+}
+
+static void pblk_rail_notify_reader_up(struct pblk *pblk, int lun)
+{
+ /* Make sure that write is completed before releasing busy bit */
+ smp_mb__before_atomic();
+ WARN_ON(!test_and_clear_bit(lun, pblk->rail.busy_bitmap));
+}
+
+int pblk_rail_lun_busy(struct pblk *pblk, struct ppa_addr ppa)
+{
+ struct nvm_tgt_dev *dev = pblk->dev;
+ struct nvm_geo *geo = &dev->geo;
+ int lun_pos = pblk_ppa_to_pos(geo, ppa);
+
+ return test_bit(lun_pos, pblk->rail.busy_bitmap);
+}
+
+/* Enforces one writer per stride */
+int pblk_rail_down_stride(struct pblk *pblk, int lun_pos, int timeout)
+{
+ struct pblk_lun *rlun;
+ int strides = pblk_rail_nr_parity_luns(pblk);
+ int stride = lun_pos % strides;
+ int ret;
+
+ rlun = &pblk->luns[stride];
+ ret = down_timeout(&rlun->wr_sem, timeout);
+ pblk_rail_notify_reader_down(pblk, lun_pos);
+
+ return ret;
+}
+
+void pblk_rail_up_stride(struct pblk *pblk, int lun_pos)
+{
+ struct pblk_lun *rlun;
+ int strides = pblk_rail_nr_parity_luns(pblk);
+ int stride = lun_pos % strides;
+
+ pblk_rail_notify_reader_up(pblk, lun_pos);
+ rlun = &pblk->luns[stride];
+ up(&rlun->wr_sem);
+}
+
+/* Determine whether a sector holds data, meta or is bad*/
+bool pblk_rail_valid_sector(struct pblk *pblk, struct pblk_line *line, int pos)
+{
+ struct pblk_line_meta *lm = &pblk->lm;
+ struct nvm_tgt_dev *dev = pblk->dev;
+ struct nvm_geo *geo = &dev->geo;
+ struct ppa_addr ppa;
+ int lun;
+
+ if (pos >= line->smeta_ssec && pos < (line->smeta_ssec + lm->smeta_sec))
+ return false;
+
+ if (pos >= line->emeta_ssec &&
+ pos < (line->emeta_ssec + lm->emeta_sec[0]))
+ return false;
+
+ ppa = addr_to_gen_ppa(pblk, pos, line->id);
+ lun = pblk_ppa_to_pos(geo, ppa);
+
+ return !test_bit(lun, line->blk_bitmap);
+}
+
+/* Delay rb overwrite until whole stride has been written */
+int pblk_rail_rb_delay(struct pblk_rb *rb)
+{
+ struct pblk *pblk = container_of(rb, struct pblk, rwb);
+
+ return pblk_rail_sec_per_stripe(pblk);
+}
+
+static unsigned int pblk_rail_sec_to_stride(struct pblk *pblk, unsigned int sec)
+{
+ unsigned int sec_in_stripe = sec % pblk_rail_sec_per_stripe(pblk);
+ int page = sec_in_stripe / pblk->min_write_pgs;
+
+ return page % pblk_rail_nr_parity_luns(pblk);
+}
+
+static unsigned int pblk_rail_sec_to_idx(struct pblk *pblk, unsigned int sec)
+{
+ unsigned int sec_in_stripe = sec % pblk_rail_sec_per_stripe(pblk);
+
+ return sec_in_stripe / pblk_rail_psec_per_stripe(pblk);
+}
+
+static void pblk_rail_data_parity(void *dest, void *src)
+{
+ unsigned int i;
+
+ for (i = 0; i < PBLK_EXPOSED_PAGE_SIZE / sizeof(unsigned long); i++)
+ ((unsigned long *)dest)[i] ^= ((unsigned long *)src)[i];
+}
+
+static void pblk_rail_lba_parity(u64 *dest, u64 *src)
+{
+ *dest ^= *src;
+}
+
+/* Tracks where a sector is located in the rwb */
+void pblk_rail_track_sec(struct pblk *pblk, struct pblk_line *line, int cur_sec,
+ int sentry, int nr_valid)
+{
+ int stride, idx, pos;
+
+ stride = pblk_rail_sec_to_stride(pblk, cur_sec);
+ idx = pblk_rail_sec_to_idx(pblk, cur_sec);
+ pos = pblk_rb_wrap_pos(&pblk->rwb, sentry);
+ pblk->rail.p2b[stride][idx].pos = pos;
+ pblk->rail.p2b[stride][idx].nr_valid = nr_valid;
+}
+
+/* RAIL's sector mapping function */
+static void pblk_rail_map_sec(struct pblk *pblk, struct pblk_line *line,
+ int sentry, struct pblk_sec_meta *meta_list,
+ __le64 *lba_list, struct ppa_addr ppa)
+{
+ struct pblk_w_ctx *w_ctx;
+ __le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+
+ kref_get(&line->ref);
+
+ if (sentry & PBLK_RAIL_PARITY_WRITE) {
+ u64 *lba;
+
+ sentry &= ~PBLK_RAIL_PARITY_WRITE;
+ lba = &pblk->rail.lba[sentry];
+ meta_list->lba = cpu_to_le64(*lba);
+ *lba_list = cpu_to_le64(*lba);
+ line->nr_valid_lbas++;
+ } else {
+ w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry);
+ w_ctx->ppa = ppa;
+ meta_list->lba = cpu_to_le64(w_ctx->lba);
+ *lba_list = cpu_to_le64(w_ctx->lba);
+
+ if (*lba_list != addr_empty)
+ line->nr_valid_lbas++;
+ else
+ atomic64_inc(&pblk->pad_wa);
+ }
+}
+
+int pblk_rail_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;
+ __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;
+
+ /* If we cannot allocate a new line, make sure to store metadata
+ * on current line and then fail
+ */
+ line = pblk_line_replace_data(pblk);
+ pblk_line_close_meta(pblk, prev_line);
+
+ if (!line)
+ return -EINTR;
+ }
+
+ emeta = line->emeta;
+ lba_list = emeta_to_lbas(pblk, emeta->buf);
+
+ paddr = pblk_alloc_page(pblk, line, nr_secs);
+
+ pblk_rail_track_sec(pblk, line, paddr, sentry, valid_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) {
+ pblk_rail_map_sec(pblk, line, sentry + i, &meta_list[i],
+ &lba_list[paddr], ppa_list[i]);
+ } else {
+ lba_list[paddr] = meta_list[i].lba = addr_empty;
+ __pblk_map_invalidate(pblk, line, paddr);
+ }
+ }
+
+ pblk_down_rq(pblk, ppa_list[0], lun_bitmap);
+ return 0;
+}
+
+/* RAIL Initialization and tear down */
+int pblk_rail_init(struct pblk *pblk)
+{
+ struct pblk_line_meta *lm = &pblk->lm;
+ int i, p2be;
+ unsigned int nr_strides;
+ unsigned int psecs;
+ void *kaddr;
+
+ if (!PBLK_RAIL_STRIDE_WIDTH)
+ return 0;
+
+ if (((lm->blk_per_line % PBLK_RAIL_STRIDE_WIDTH) != 0) ||
+ (lm->blk_per_line < PBLK_RAIL_STRIDE_WIDTH)) {
+ pr_err("pblk: unsupported RAIL stride %i\n", lm->blk_per_line);
+ return -EINVAL;
+ }
+
+ psecs = pblk_rail_psec_per_stripe(pblk);
+ nr_strides = pblk_rail_sec_per_stripe(pblk) / PBLK_RAIL_STRIDE_WIDTH;
+
+ pblk->rail.p2b = kmalloc_array(nr_strides, sizeof(struct p2b_entry *),
+ GFP_KERNEL);
+ if (!pblk->rail.p2b)
+ return -ENOMEM;
+
+ for (p2be = 0; p2be < nr_strides; p2be++) {
+ pblk->rail.p2b[p2be] = kmalloc_array(PBLK_RAIL_STRIDE_WIDTH - 1,
+ sizeof(struct p2b_entry),
+ GFP_KERNEL);
+ if (!pblk->rail.p2b[p2be])
+ goto free_p2b_entries;
+ }
+
+ pblk->rail.data = kmalloc(psecs * sizeof(void *), GFP_KERNEL);
+ if (!pblk->rail.data)
+ goto free_p2b_entries;
+
+ pblk->rail.pages = alloc_pages(GFP_KERNEL, get_count_order(psecs));
+ if (!pblk->rail.pages)
+ goto free_data;
+
+ kaddr = page_address(pblk->rail.pages);
+ for (i = 0; i < psecs; i++)
+ pblk->rail.data[i] = kaddr + i * PBLK_EXPOSED_PAGE_SIZE;
+
+ pblk->rail.lba = kmalloc_array(psecs, sizeof(u64 *), GFP_KERNEL);
+ if (!pblk->rail.lba)
+ goto free_pages;
+
+ /* Subtract parity bits from device capacity */
+ pblk->capacity = pblk->capacity * (PBLK_RAIL_STRIDE_WIDTH - 1) /
+ PBLK_RAIL_STRIDE_WIDTH;
+
+ pblk->map_page = pblk_rail_map_page_data;
+
+ return 0;
+
+free_pages:
+ free_pages((unsigned long)page_address(pblk->rail.pages),
+ get_count_order(psecs));
+free_data:
+ kfree(pblk->rail.data);
+free_p2b_entries:
+ for (p2be = p2be - 1; p2be >= 0; p2be--)
+ kfree(pblk->rail.p2b[p2be]);
+ kfree(pblk->rail.p2b);
+
+ return -ENOMEM;
+}
+
+void pblk_rail_free(struct pblk *pblk)
+{
+ unsigned int i;
+ unsigned int nr_strides;
+ unsigned int psecs;
+
+ psecs = pblk_rail_psec_per_stripe(pblk);
+ nr_strides = pblk_rail_sec_per_stripe(pblk) / PBLK_RAIL_STRIDE_WIDTH;
+
+ kfree(pblk->rail.lba);
+ free_pages((unsigned long)page_address(pblk->rail.pages),
+ get_count_order(psecs));
+ kfree(pblk->rail.data);
+ for (i = 0; i < nr_strides; i++)
+ kfree(pblk->rail.p2b[i]);
+ kfree(pblk->rail.p2b);
+}
+
+/* PBLK supports 64 ppas max. By performing RAIL reads, a sector is read using
+ * multiple ppas which can lead to violation of the 64 ppa limit. In this case,
+ * split the bio
+ */
+static void pblk_rail_bio_split(struct pblk *pblk, struct bio **bio, int sec)
+{
+ struct nvm_tgt_dev *dev = pblk->dev;
+ struct bio *split;
+
+ sec *= (dev->geo.csecs >> 9);
+
+ split = bio_split(*bio, sec, GFP_KERNEL, &pblk_bio_set);
+ /* there isn't chance to merge the split bio */
+ split->bi_opf |= REQ_NOMERGE;
+ bio_set_flag(*bio, BIO_QUEUE_ENTERED);
+ bio_chain(split, *bio);
+ generic_make_request(*bio);
+ *bio = split;
+}
+
+/* RAIL's Write Path */
+static int pblk_rail_sched_parity(struct pblk *pblk)
+{
+ struct pblk_line *line = pblk_line_get_data(pblk);
+ unsigned int sec_in_stripe;
+
+ while (1) {
+ sec_in_stripe = line->cur_sec % pblk_rail_sec_per_stripe(pblk);
+
+ /* Schedule parity write at end of data section */
+ if (sec_in_stripe >= pblk_rail_dsec_per_stripe(pblk))
+ return 1;
+
+ /* Skip bad blocks and meta sectors until we find a valid sec */
+ if (test_bit(line->cur_sec, line->map_bitmap))
+ line->cur_sec += pblk->min_write_pgs;
+ else
+ break;
+ }
+
+ return 0;
+}
+
+/* Mark RAIL parity sectors as invalid sectors so they will be gc'ed */
+void pblk_rail_line_close(struct pblk *pblk, struct pblk_line *line)
+{
+ int off, bit;
+
+ for (off = pblk_rail_dsec_per_stripe(pblk);
+ off < pblk->lm.sec_per_line;
+ off += pblk_rail_sec_per_stripe(pblk)) {
+ for (bit = 0; bit < pblk_rail_psec_per_stripe(pblk); bit++)
+ set_bit(off + bit, line->invalid_bitmap);
+ }
+}
+
+void pblk_rail_end_io_write(struct nvm_rq *rqd)
+{
+ struct pblk *pblk = rqd->private;
+ struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+
+ if (rqd->error) {
+ pblk_log_write_err(pblk, rqd);
+ return pblk_end_w_fail(pblk, rqd);
+ }
+#ifdef CONFIG_NVM_DEBUG
+ else
+ WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
+#endif
+
+ pblk_up_rq(pblk, c_ctx->lun_bitmap);
+
+ pblk_rq_to_line_put(pblk, rqd);
+ bio_put(rqd->bio);
+ pblk_free_rqd(pblk, rqd, PBLK_WRITE);
+
+ atomic_dec(&pblk->inflight_io);
+}
+
+static int pblk_rail_read_to_bio(struct pblk *pblk, struct nvm_rq *rqd,
+ struct bio *bio, unsigned int stride,
+ unsigned int nr_secs, unsigned int paddr)
+{
+ struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+ int sec, i;
+ int nr_data = PBLK_RAIL_STRIDE_WIDTH - 1;
+ struct pblk_line *line = pblk_line_get_data(pblk);
+
+ c_ctx->nr_valid = nr_secs;
+ /* sentry indexes rail page buffer, instead of rwb */
+ c_ctx->sentry = stride * pblk->min_write_pgs;
+ c_ctx->sentry |= PBLK_RAIL_PARITY_WRITE;
+
+ for (sec = 0; sec < pblk->min_write_pgs; sec++) {
+ void *pg_addr;
+ struct page *page;
+ u64 *lba;
+
+ lba = &pblk->rail.lba[stride * pblk->min_write_pgs + sec];
+ pg_addr = pblk->rail.data[stride * pblk->min_write_pgs + sec];
+ page = virt_to_page(pg_addr);
+
+ if (!page) {
+ pr_err("pblk: could not allocate RAIL bio page %p\n",
+ pg_addr);
+ return -NVM_IO_ERR;
+ }
+
+ if (bio_add_page(bio, page, pblk->rwb.seg_size, 0) !=
+ pblk->rwb.seg_size) {
+ pr_err("pblk: could not add page to RAIL bio\n");
+ return -NVM_IO_ERR;
+ }
+
+ *lba = 0;
+ memset(pg_addr, 0, PBLK_EXPOSED_PAGE_SIZE);
+
+ for (i = 0; i < nr_data; i++) {
+ struct pblk_rb_entry *entry;
+ struct pblk_w_ctx *w_ctx;
+ u64 lba_src;
+ unsigned int pos;
+ unsigned int cur;
+ int distance = pblk_rail_psec_per_stripe(pblk);
+
+ cur = paddr - distance * (nr_data - i) + sec;
+
+ if (!pblk_rail_valid_sector(pblk, line, cur))
+ continue;
+
+ pos = pblk->rail.p2b[stride][i].pos;
+ pos = pblk_rb_wrap_pos(&pblk->rwb, pos + sec);
+ entry = &pblk->rwb.entries[pos];
+ w_ctx = &entry->w_ctx;
+ lba_src = w_ctx->lba;
+
+ if (sec < pblk->rail.p2b[stride][i].nr_valid &&
+ lba_src != ADDR_EMPTY) {
+ pblk_rail_data_parity(pg_addr, entry->data);
+ pblk_rail_lba_parity(lba, &lba_src);
+ }
+ }
+ }
+
+ return 0;
+}
+
+int pblk_rail_submit_write(struct pblk *pblk)
+{
+ int i;
+ struct nvm_rq *rqd;
+ struct bio *bio;
+ struct pblk_line *line = pblk_line_get_data(pblk);
+ int start, end, bb_offset;
+ unsigned int stride = 0;
+
+ if (!pblk_rail_sched_parity(pblk))
+ return 0;
+
+ start = line->cur_sec;
+ bb_offset = start % pblk_rail_sec_per_stripe(pblk);
+ end = start + pblk_rail_sec_per_stripe(pblk) - bb_offset;
+
+ for (i = start; i < end; i += pblk->min_write_pgs, stride++) {
+ /* Do not generate parity in this slot if the sec is bad
+ * or reserved for meta.
+ * We check on the read path and perform a conventional
+ * read, to avoid reading parity from the bad block
+ */
+ if (!pblk_rail_valid_sector(pblk, line, i))
+ continue;
+
+ rqd = pblk_alloc_rqd(pblk, PBLK_WRITE);
+ if (IS_ERR(rqd)) {
+ pr_err("pblk: cannot allocate parity write req.\n");
+ return -ENOMEM;
+ }
+
+ bio = bio_alloc(GFP_KERNEL, pblk->min_write_pgs);
+ if (!bio) {
+ pr_err("pblk: cannot allocate parity write bio\n");
+ pblk_free_rqd(pblk, rqd, PBLK_WRITE);
+ return -ENOMEM;
+ }
+
+ bio->bi_iter.bi_sector = 0; /* internal bio */
+ bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+ rqd->bio = bio;
+
+ pblk_rail_read_to_bio(pblk, rqd, bio, stride,
+ pblk->min_write_pgs, i);
+
+ if (pblk_submit_io_set(pblk, rqd, pblk_rail_end_io_write)) {
+ bio_put(rqd->bio);
+ pblk_free_rqd(pblk, rqd, PBLK_WRITE);
+
+ return -NVM_IO_ERR;
+ }
+ }
+
+ return 0;
+}
+
+/* RAIL's Read Path */
+static void pblk_rail_end_io_read(struct nvm_rq *rqd)
+{
+ struct pblk *pblk = rqd->private;
+ struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+ struct pblk_pr_ctx *pr_ctx = r_ctx->private;
+ struct bio *new_bio = rqd->bio;
+ struct bio *bio = pr_ctx->orig_bio;
+ struct bio_vec src_bv, dst_bv;
+ struct pblk_sec_meta *meta_list = rqd->meta_list;
+ int bio_init_idx = pr_ctx->bio_init_idx;
+ int nr_secs = pr_ctx->orig_nr_secs;
+ __le64 *lba_list_mem, *lba_list_media;
+ __le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+ void *src_p, *dst_p;
+ int i, r, rail_ppa = 0;
+ unsigned char valid;
+
+ if (unlikely(rqd->nr_ppas == 1)) {
+ struct ppa_addr ppa;
+
+ ppa = rqd->ppa_addr;
+ rqd->ppa_list = pr_ctx->ppa_ptr;
+ rqd->dma_ppa_list = pr_ctx->dma_ppa_list;
+ rqd->ppa_list[0] = ppa;
+ }
+
+ /* Re-use allocated memory for intermediate lbas */
+ lba_list_mem = (((void *)rqd->ppa_list) + pblk_dma_ppa_size);
+ lba_list_media = (((void *)rqd->ppa_list) + 2 * pblk_dma_ppa_size);
+
+ for (i = 0; i < rqd->nr_ppas; i++)
+ lba_list_media[i] = meta_list[i].lba;
+ for (i = 0; i < nr_secs; i++)
+ meta_list[i].lba = lba_list_mem[i];
+
+ for (i = 0; i < nr_secs; i++) {
+ struct pblk_line *line;
+ u64 meta_lba = 0x0UL, mlba;
+
+ line = pblk_ppa_to_line(pblk, rqd->ppa_list[rail_ppa]);
+
+ valid = bitmap_weight(pr_ctx->bitmap, PBLK_RAIL_STRIDE_WIDTH);
+ bitmap_shift_right(pr_ctx->bitmap, pr_ctx->bitmap,
+ PBLK_RAIL_STRIDE_WIDTH, PR_BITMAP_SIZE);
+
+ if (valid == 0) /* Skip cached reads */
+ continue;
+
+ kref_put(&line->ref, pblk_line_put);
+
+ dst_bv = bio->bi_io_vec[bio_init_idx + i];
+ dst_p = kmap_atomic(dst_bv.bv_page);
+
+ memset(dst_p + dst_bv.bv_offset, 0, PBLK_EXPOSED_PAGE_SIZE);
+ meta_list[i].lba = cpu_to_le64(0x0UL);
+
+ for (r = 0; r < valid; r++, rail_ppa++) {
+ src_bv = new_bio->bi_io_vec[rail_ppa];
+
+ if (lba_list_media[rail_ppa] != addr_empty) {
+ src_p = kmap_atomic(src_bv.bv_page);
+ pblk_rail_data_parity(dst_p + dst_bv.bv_offset,
+ src_p + src_bv.bv_offset);
+ mlba = le64_to_cpu(lba_list_media[rail_ppa]);
+ pblk_rail_lba_parity(&meta_lba, &mlba);
+ kunmap_atomic(src_p);
+ }
+
+ mempool_free(src_bv.bv_page, &pblk->page_bio_pool);
+ }
+ meta_list[i].lba = cpu_to_le64(meta_lba);
+ kunmap_atomic(dst_p);
+ }
+
+ bio_put(new_bio);
+ rqd->nr_ppas = pr_ctx->orig_nr_secs;
+ kfree(pr_ctx);
+ rqd->bio = NULL;
+
+ bio_endio(bio);
+ __pblk_end_io_read(pblk, rqd, false);
+}
+
+/* Converts original ppa into ppa list of RAIL reads */
+static int pblk_rail_setup_ppas(struct pblk *pblk, struct ppa_addr ppa,
+ struct ppa_addr *rail_ppas,
+ unsigned char *pvalid, int *nr_rail_ppas,
+ int *rail_reads)
+{
+ struct nvm_tgt_dev *dev = pblk->dev;
+ struct nvm_geo *geo = &dev->geo;
+ struct ppa_addr rail_ppa = ppa;
+ unsigned int lun_pos = pblk_ppa_to_pos(geo, ppa);
+ unsigned int strides = pblk_rail_nr_parity_luns(pblk);
+ struct pblk_line *line;
+ unsigned int i;
+ int ppas = *nr_rail_ppas;
+ int valid = 0;
+
+ for (i = 1; i < PBLK_RAIL_STRIDE_WIDTH; i++) {
+ unsigned int neighbor, lun, chnl;
+ int laddr;
+
+ neighbor = pblk_rail_wrap_lun(pblk, lun_pos + i * strides);
+
+ lun = pblk_pos_to_lun(geo, neighbor);
+ chnl = pblk_pos_to_chnl(geo, neighbor);
+ pblk_dev_ppa_set_lun(&rail_ppa, lun);
+ pblk_dev_ppa_set_chnl(&rail_ppa, chnl);
+
+ line = pblk_ppa_to_line(pblk, rail_ppa);
+ laddr = pblk_dev_ppa_to_line_addr(pblk, rail_ppa);
+
+ /* Do not read from bad blocks */
+ if (!pblk_rail_valid_sector(pblk, line, laddr)) {
+ /* Perform regular read if parity sector is bad */
+ if (neighbor >= pblk_rail_nr_data_luns(pblk))
+ return 0;
+
+ /* If any other neighbor is bad we can just skip it */
+ continue;
+ }
+
+ rail_ppas[ppas++] = rail_ppa;
+ valid++;
+ }
+
+ if (valid == 1)
+ return 0;
+
+ *pvalid = valid;
+ *nr_rail_ppas = ppas;
+ (*rail_reads)++;
+ return 1;
+}
+
+static void pblk_rail_set_bitmap(struct pblk *pblk, struct ppa_addr *ppa_list,
+ int ppa, struct ppa_addr *rail_ppa_list,
+ int *nr_rail_ppas, unsigned long *read_bitmap,
+ unsigned long *pvalid, int *rail_reads)
+{
+ unsigned char valid;
+
+ if (test_bit(ppa, read_bitmap))
+ return;
+
+ if (pblk_rail_lun_busy(pblk, ppa_list[ppa]) &&
+ pblk_rail_setup_ppas(pblk, ppa_list[ppa],
+ rail_ppa_list, &valid,
+ nr_rail_ppas, rail_reads)) {
+ WARN_ON(test_and_set_bit(ppa, read_bitmap));
+ bitmap_set(pvalid, ppa * PBLK_RAIL_STRIDE_WIDTH, valid);
+ } else {
+ rail_ppa_list[(*nr_rail_ppas)++] = ppa_list[ppa];
+ bitmap_set(pvalid, ppa * PBLK_RAIL_STRIDE_WIDTH, 1);
+ }
+}
+
+int pblk_rail_read_bio(struct pblk *pblk, struct nvm_rq *rqd, int blba,
+ unsigned long *read_bitmap, int bio_init_idx,
+ struct bio **bio)
+{
+ struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+ struct pblk_pr_ctx *pr_ctx;
+ struct ppa_addr rail_ppa_list[NVM_MAX_VLBA];
+ DECLARE_BITMAP(pvalid, PR_BITMAP_SIZE);
+ int nr_secs = rqd->nr_ppas;
+ bool read_empty = bitmap_empty(read_bitmap, nr_secs);
+ int nr_rail_ppas = 0, rail_reads = 0;
+ int i;
+ int ret;
+
+ /* Fully cached reads should not enter this path */
+ WARN_ON(bitmap_full(read_bitmap, nr_secs));
+
+ bitmap_zero(pvalid, PR_BITMAP_SIZE);
+ if (rqd->nr_ppas == 1) {
+ pblk_rail_set_bitmap(pblk, &rqd->ppa_addr, 0, rail_ppa_list,
+ &nr_rail_ppas, read_bitmap, pvalid,
+ &rail_reads);
+
+ if (nr_rail_ppas == 1) {
+ memcpy(&rqd->ppa_addr, rail_ppa_list,
+ nr_rail_ppas * sizeof(struct ppa_addr));
+ } else {
+ rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
+ rqd->dma_ppa_list = rqd->dma_meta_list +
+ pblk_dma_meta_size;
+ memcpy(rqd->ppa_list, rail_ppa_list,
+ nr_rail_ppas * sizeof(struct ppa_addr));
+ }
+ } else {
+ for (i = 0; i < rqd->nr_ppas; i++) {
+ pblk_rail_set_bitmap(pblk, rqd->ppa_list, i,
+ rail_ppa_list, &nr_rail_ppas,
+ read_bitmap, pvalid, &rail_reads);
+
+ /* Don't split if this it the last ppa of the rqd */
+ if (((nr_rail_ppas + PBLK_RAIL_STRIDE_WIDTH) >=
+ NVM_MAX_VLBA) && (i + 1 < rqd->nr_ppas)) {
+ struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+
+ pblk_rail_bio_split(pblk, bio, i + 1);
+ rqd->nr_ppas = pblk_get_secs(*bio);
+ r_ctx->private = *bio;
+ break;
+ }
+ }
+ memcpy(rqd->ppa_list, rail_ppa_list,
+ nr_rail_ppas * sizeof(struct ppa_addr));
+ }
+
+ if (bitmap_empty(read_bitmap, rqd->nr_ppas))
+ return NVM_IO_REQUEUE;
+
+ if (read_empty && !bitmap_empty(read_bitmap, rqd->nr_ppas))
+ bio_advance(*bio, (rqd->nr_ppas) * PBLK_EXPOSED_PAGE_SIZE);
+
+ if (pblk_setup_partial_read(pblk, rqd, bio_init_idx, read_bitmap,
+ nr_rail_ppas))
+ return NVM_IO_ERR;
+
+ rqd->end_io = pblk_rail_end_io_read;
+ pr_ctx = r_ctx->private;
+ bitmap_copy(pr_ctx->bitmap, pvalid, PR_BITMAP_SIZE);
+
+ ret = pblk_submit_io(pblk, rqd);
+ if (ret) {
+ bio_put(rqd->bio);
+ pr_err("pblk: partial RAIL read IO submission failed\n");
+ /* Free allocated pages in new bio */
+ pblk_bio_free_pages(pblk, rqd->bio, 0, rqd->bio->bi_vcnt);
+ kfree(pr_ctx);
+ __pblk_end_io_read(pblk, rqd, false);
+ return NVM_IO_ERR;
+ }
+
+ return NVM_IO_OK;
+}
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index bd88784e51d9..01fe4362b27e 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -28,6 +28,7 @@
#include <linux/vmalloc.h>
#include <linux/crc32.h>
#include <linux/uuid.h>
+#include <linux/log2.h>
#include <linux/lightnvm.h>
@@ -45,7 +46,7 @@
#define PBLK_COMMAND_TIMEOUT_MS 30000
/* Max 512 LUNs per device */
-#define PBLK_MAX_LUNS_BITMAP (4)
+#define PBLK_MAX_LUNS_BITMAP (512)
#define NR_PHY_IN_LOG (PBLK_EXPOSED_PAGE_SIZE / PBLK_SECTOR)
@@ -123,6 +124,13 @@ struct pblk_g_ctx {
u64 lba;
};
+#ifdef CONFIG_NVM_PBLK_RAIL
+#define PBLK_RAIL_STRIDE_WIDTH 4
+#define PR_BITMAP_SIZE (NVM_MAX_VLBA * PBLK_RAIL_STRIDE_WIDTH)
+#else
+#define PR_BITMAP_SIZE NVM_MAX_VLBA
+#endif
+
/* partial read context */
struct pblk_pr_ctx {
struct bio *orig_bio;
@@ -604,6 +612,39 @@ struct pblk_addrf {
int sec_ws_stripe;
};
+#ifdef CONFIG_NVM_PBLK_RAIL
+
+struct p2b_entry {
+ int pos;
+ int nr_valid;
+};
+
+struct pblk_rail {
+ struct p2b_entry **p2b; /* Maps RAIL sectors to rb pos */
+ struct page *pages; /* Pages to hold parity writes */
+ void **data; /* Buffer that holds parity pages */
+ DECLARE_BITMAP(busy_bitmap, PBLK_MAX_LUNS_BITMAP);
+ u64 *lba; /* Buffer to compute LBA parity */
+};
+
+/* Initialize and tear down RAIL */
+int pblk_rail_init(struct pblk *pblk);
+void pblk_rail_free(struct pblk *pblk);
+/* Adjust some system parameters */
+bool pblk_rail_meta_distance(struct pblk_line *data_line);
+int pblk_rail_rb_delay(struct pblk_rb *rb);
+/* Core */
+void pblk_rail_line_close(struct pblk *pblk, struct pblk_line *line);
+int pblk_rail_down_stride(struct pblk *pblk, int lun, int timeout);
+void pblk_rail_up_stride(struct pblk *pblk, int lun);
+/* Write path */
+int pblk_rail_submit_write(struct pblk *pblk);
+/* Read Path */
+int pblk_rail_read_bio(struct pblk *pblk, struct nvm_rq *rqd, int blba,
+ unsigned long *read_bitmap, int bio_init_idx,
+ struct bio **bio);
+#endif /* CONFIG_NVM_PBLK_RAIL */
+
typedef int (pblk_map_page_fn)(struct pblk *pblk, unsigned int sentry,
struct ppa_addr *ppa_list,
unsigned long *lun_bitmap,
@@ -1115,6 +1156,26 @@ static inline u64 pblk_dev_ppa_to_line_addr(struct pblk *pblk,
return paddr;
}
+static inline int pblk_pos_to_lun(struct nvm_geo *geo, int pos)
+{
+ return pos >> ilog2(geo->num_ch);
+}
+
+static inline int pblk_pos_to_chnl(struct nvm_geo *geo, int pos)
+{
+ return pos % geo->num_ch;
+}
+
+static inline void pblk_dev_ppa_set_lun(struct ppa_addr *p, int lun)
+{
+ p->a.lun = lun;
+}
+
+static inline void pblk_dev_ppa_set_chnl(struct ppa_addr *p, int chnl)
+{
+ p->a.ch = chnl;
+}
+
static inline struct ppa_addr pblk_ppa32_to_ppa64(struct pblk *pblk, u32 ppa32)
{
struct nvm_tgt_dev *dev = pblk->dev;
--
2.17.1
