v4.19.13 snapshot.
diff --git a/drivers/lightnvm/pblk-cache.c b/drivers/lightnvm/pblk-cache.c
new file mode 100644
index 0000000..f565a56
--- /dev/null
+++ b/drivers/lightnvm/pblk-cache.c
@@ -0,0 +1,134 @@
+/*
+ * 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-cache.c - pblk's write cache
+ */
+
+#include "pblk.h"
+
+int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
+{
+ struct request_queue *q = pblk->dev->q;
+ struct pblk_w_ctx w_ctx;
+ sector_t lba = pblk_get_lba(bio);
+ unsigned long start_time = jiffies;
+ unsigned int bpos, pos;
+ int nr_entries = pblk_get_secs(bio);
+ int i, ret;
+
+ generic_start_io_acct(q, REQ_OP_WRITE, bio_sectors(bio),
+ &pblk->disk->part0);
+
+ /* Update the write buffer head (mem) with the entries that we can
+ * write. The write in itself cannot fail, so there is no need to
+ * rollback from here on.
+ */
+retry:
+ ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
+ switch (ret) {
+ case NVM_IO_REQUEUE:
+ io_schedule();
+ goto retry;
+ case NVM_IO_ERR:
+ pblk_pipeline_stop(pblk);
+ goto out;
+ }
+
+ pblk_ppa_set_empty(&w_ctx.ppa);
+ w_ctx.flags = flags;
+ if (bio->bi_opf & REQ_PREFLUSH) {
+ w_ctx.flags |= PBLK_FLUSH_ENTRY;
+ pblk_write_kick(pblk);
+ }
+
+ if (unlikely(!bio_has_data(bio)))
+ goto out;
+
+ for (i = 0; i < nr_entries; i++) {
+ void *data = bio_data(bio);
+
+ w_ctx.lba = lba + i;
+
+ pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
+ pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
+
+ bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
+ }
+
+ atomic64_add(nr_entries, &pblk->user_wa);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+ atomic_long_add(nr_entries, &pblk->inflight_writes);
+ atomic_long_add(nr_entries, &pblk->req_writes);
+#endif
+
+ pblk_rl_inserted(&pblk->rl, nr_entries);
+
+out:
+ generic_end_io_acct(q, REQ_OP_WRITE, &pblk->disk->part0, start_time);
+ pblk_write_should_kick(pblk);
+ return ret;
+}
+
+/*
+ * On GC the incoming lbas are not necessarily sequential. Also, some of the
+ * lbas might not be valid entries, which are marked as empty by the GC thread
+ */
+int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
+{
+ struct pblk_w_ctx w_ctx;
+ unsigned int bpos, pos;
+ void *data = gc_rq->data;
+ int i, valid_entries;
+
+ /* Update the write buffer head (mem) with the entries that we can
+ * write. The write in itself cannot fail, so there is no need to
+ * rollback from here on.
+ */
+retry:
+ if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
+ io_schedule();
+ goto retry;
+ }
+
+ w_ctx.flags = PBLK_IOTYPE_GC;
+ pblk_ppa_set_empty(&w_ctx.ppa);
+
+ for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
+ if (gc_rq->lba_list[i] == ADDR_EMPTY)
+ continue;
+
+ w_ctx.lba = gc_rq->lba_list[i];
+
+ pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
+ pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
+ gc_rq->paddr_list[i], pos);
+
+ data += PBLK_EXPOSED_PAGE_SIZE;
+ valid_entries++;
+ }
+
+ WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
+ "pblk: inconsistent GC write\n");
+
+ atomic64_add(valid_entries, &pblk->gc_wa);
+
+#ifdef CONFIG_NVM_PBLK_DEBUG
+ atomic_long_add(valid_entries, &pblk->inflight_writes);
+ atomic_long_add(valid_entries, &pblk->recov_gc_writes);
+#endif
+
+ pblk_write_should_kick(pblk);
+ return NVM_IO_OK;
+}