1 files changed, 414 insertions, 0 deletions
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
new file mode 100644
index 000000000000..aef6fd7c4a0c
--- /dev/null
+++ b/drivers/lightnvm/pblk-write.c
@@ -0,0 +1,414 @@
+/*
+ * 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-write.c - pblk's write path from write buffer to media
+ */
+
+#include "pblk.h"
+
+static void pblk_sync_line(struct pblk *pblk, struct pblk_line *line)
+{
+#ifdef CONFIG_NVM_DEBUG
+	atomic_long_inc(&pblk->sync_writes);
+#endif
+
+	/* Counter protected by rb sync lock */
+	line->left_ssecs--;
+	if (!line->left_ssecs)
+		pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws);
+}
+
+static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
+				    struct pblk_c_ctx *c_ctx)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+	struct bio *original_bio;
+	unsigned long ret;
+	int i;
+
+	for (i = 0; i < c_ctx->nr_valid; i++) {
+		struct pblk_w_ctx *w_ctx;
+		struct ppa_addr p;
+		struct pblk_line *line;
+
+		w_ctx = pblk_rb_w_ctx(&pblk->rwb, c_ctx->sentry + i);
+
+		p = rqd->ppa_list[i];
+		line = &pblk->lines[pblk_dev_ppa_to_line(p)];
+		pblk_sync_line(pblk, line);
+
+		while ((original_bio = bio_list_pop(&w_ctx->bios)))
+			bio_endio(original_bio);
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_long_add(c_ctx->nr_valid, &pblk->compl_writes);
+#endif
+
+	ret = pblk_rb_sync_advance(&pblk->rwb, c_ctx->nr_valid);
+
+	if (rqd->meta_list)
+		nvm_dev_dma_free(dev->parent, rqd->meta_list,
+							rqd->dma_meta_list);
+
+	bio_put(rqd->bio);
+	pblk_free_rqd(pblk, rqd, WRITE);
+
+	return ret;
+}
+
+static unsigned long pblk_end_queued_w_bio(struct pblk *pblk,
+					   struct nvm_rq *rqd,
+					   struct pblk_c_ctx *c_ctx)
+{
+	list_del(&c_ctx->list);
+	return pblk_end_w_bio(pblk, rqd, c_ctx);
+}
+
+static void pblk_complete_write(struct pblk *pblk, struct nvm_rq *rqd,
+				struct pblk_c_ctx *c_ctx)
+{
+	struct pblk_c_ctx *c, *r;
+	unsigned long flags;
+	unsigned long pos;
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_long_sub(c_ctx->nr_valid, &pblk->inflight_writes);
+#endif
+
+	pblk_up_rq(pblk, rqd->ppa_list, rqd->nr_ppas, c_ctx->lun_bitmap);
+
+	pos = pblk_rb_sync_init(&pblk->rwb, &flags);
+	if (pos == c_ctx->sentry) {
+		pos = pblk_end_w_bio(pblk, rqd, c_ctx);
+
+retry:
+		list_for_each_entry_safe(c, r, &pblk->compl_list, list) {
+			rqd = nvm_rq_from_c_ctx(c);
+			if (c->sentry == pos) {
+				pos = pblk_end_queued_w_bio(pblk, rqd, c);
+				goto retry;
+			}
+		}
+	} else {
+		WARN_ON(nvm_rq_from_c_ctx(c_ctx) != rqd);
+		list_add_tail(&c_ctx->list, &pblk->compl_list);
+	}
+	pblk_rb_sync_end(&pblk->rwb, &flags);
+}
+
+/* When a write fails, we are not sure whether the block has grown bad or a page
+ * range is more susceptible to write errors. If a high number of pages fail, we
+ * assume that the block is bad and we mark it accordingly. In all cases, we
+ * remap and resubmit the failed entries as fast as possible; if a flush is
+ * waiting on a completion, the whole stack would stall otherwise.
+ */
+static void pblk_end_w_fail(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	void *comp_bits = &rqd->ppa_status;
+	struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_rec_ctx *recovery;
+	struct ppa_addr *ppa_list = rqd->ppa_list;
+	int nr_ppas = rqd->nr_ppas;
+	unsigned int c_entries;
+	int bit, ret;
+
+	if (unlikely(nr_ppas == 1))
+		ppa_list = &rqd->ppa_addr;
+
+	recovery = mempool_alloc(pblk->rec_pool, GFP_ATOMIC);
+	if (!recovery) {
+		pr_err("pblk: could not allocate recovery context\n");
+		return;
+	}
+	INIT_LIST_HEAD(&recovery->failed);
+
+	bit = -1;
+	while ((bit = find_next_bit(comp_bits, nr_ppas, bit + 1)) < nr_ppas) {
+		struct pblk_rb_entry *entry;
+		struct ppa_addr ppa;
+
+		/* Logic error */
+		if (bit > c_ctx->nr_valid) {
+			WARN_ONCE(1, "pblk: corrupted write request\n");
+			mempool_free(recovery, pblk->rec_pool);
+			goto out;
+		}
+
+		ppa = ppa_list[bit];
+		entry = pblk_rb_sync_scan_entry(&pblk->rwb, &ppa);
+		if (!entry) {
+			pr_err("pblk: could not scan entry on write failure\n");
+			mempool_free(recovery, pblk->rec_pool);
+			goto out;
+		}
+
+		/* The list is filled first and emptied afterwards. No need for
+		 * protecting it with a lock
+		 */
+		list_add_tail(&entry->index, &recovery->failed);
+	}
+
+	c_entries = find_first_bit(comp_bits, nr_ppas);
+	ret = pblk_recov_setup_rq(pblk, c_ctx, recovery, comp_bits, c_entries);
+	if (ret) {
+		pr_err("pblk: could not recover from write failure\n");
+		mempool_free(recovery, pblk->rec_pool);
+		goto out;
+	}
+
+	INIT_WORK(&recovery->ws_rec, pblk_submit_rec);
+	queue_work(pblk->kw_wq, &recovery->ws_rec);
+
+out:
+	pblk_complete_write(pblk, rqd, c_ctx);
+}
+
+static void pblk_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_error, "pblk: corrupted write error\n");
+#endif
+
+	pblk_complete_write(pblk, rqd, c_ctx);
+}
+
+static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			   unsigned int nr_secs)
+{
+	struct nvm_tgt_dev *dev = pblk->dev;
+
+	/* Setup write request */
+	rqd->opcode = NVM_OP_PWRITE;
+	rqd->nr_ppas = nr_secs;
+	rqd->flags = pblk_set_progr_mode(pblk, WRITE);
+	rqd->private = pblk;
+	rqd->end_io = pblk_end_io_write;
+
+	rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
+							&rqd->dma_meta_list);
+	if (!rqd->meta_list)
+		return -ENOMEM;
+
+	if (unlikely(nr_secs == 1))
+		return 0;
+
+	rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
+	rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
+
+	return 0;
+}
+
+static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			   struct pblk_c_ctx *c_ctx)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	struct pblk_line *e_line = pblk_line_get_data_next(pblk);
+	struct ppa_addr erase_ppa;
+	unsigned int valid = c_ctx->nr_valid;
+	unsigned int padded = c_ctx->nr_padded;
+	unsigned int nr_secs = valid + padded;
+	unsigned long *lun_bitmap;
+	int ret = 0;
+
+	lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
+	if (!lun_bitmap) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	c_ctx->lun_bitmap = lun_bitmap;
+
+	ret = pblk_alloc_w_rq(pblk, rqd, nr_secs);
+	if (ret) {
+		kfree(lun_bitmap);
+		goto out;
+	}
+
+	ppa_set_empty(&erase_ppa);
+	if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
+		pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
+	else
+		pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
+							valid, &erase_ppa);
+
+out:
+	if (unlikely(e_line && !ppa_empty(erase_ppa))) {
+		if (pblk_blk_erase_async(pblk, erase_ppa)) {
+			struct nvm_tgt_dev *dev = pblk->dev;
+			struct nvm_geo *geo = &dev->geo;
+			int bit;
+
+			atomic_inc(&e_line->left_eblks);
+			bit = erase_ppa.g.lun * geo->nr_chnls + erase_ppa.g.ch;
+			WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
+			up(&pblk->erase_sem);
+		}
+	}
+
+	return ret;
+}
+
+int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
+			struct pblk_c_ctx *c_ctx)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	unsigned long *lun_bitmap;
+	int ret;
+
+	lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
+	if (!lun_bitmap)
+		return -ENOMEM;
+
+	c_ctx->lun_bitmap = lun_bitmap;
+
+	ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas);
+	if (ret)
+		return ret;
+
+	pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, c_ctx->nr_valid, 0);
+
+	rqd->ppa_status = (u64)0;
+	rqd->flags = pblk_set_progr_mode(pblk, WRITE);
+
+	return ret;
+}
+
+static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
+				  unsigned int secs_to_flush)
+{
+	int secs_to_sync;
+
+	secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
+
+#ifdef CONFIG_NVM_DEBUG
+	if ((!secs_to_sync && secs_to_flush)
+			|| (secs_to_sync < 0)
+			|| (secs_to_sync > secs_avail && !secs_to_flush)) {
+		pr_err("pblk: bad sector calculation (a:%d,s:%d,f:%d)\n",
+				secs_avail, secs_to_sync, secs_to_flush);
+	}
+#endif
+
+	return secs_to_sync;
+}
+
+static int pblk_submit_write(struct pblk *pblk)
+{
+	struct bio *bio;
+	struct nvm_rq *rqd;
+	struct pblk_c_ctx *c_ctx;
+	unsigned int pgs_read;
+	unsigned int secs_avail, secs_to_sync, secs_to_com;
+	unsigned int secs_to_flush;
+	unsigned long pos;
+	int err;
+
+	/* If there are no sectors in the cache, flushes (bios without data)
+	 * will be cleared on the cache threads
+	 */
+	secs_avail = pblk_rb_read_count(&pblk->rwb);
+	if (!secs_avail)
+		return 1;
+
+	secs_to_flush = pblk_rb_sync_point_count(&pblk->rwb);
+	if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
+		return 1;
+
+	rqd = pblk_alloc_rqd(pblk, WRITE);
+	if (IS_ERR(rqd)) {
+		pr_err("pblk: cannot allocate write req.\n");
+		return 1;
+	}
+	c_ctx = nvm_rq_to_pdu(rqd);
+
+	bio = bio_alloc(GFP_KERNEL, pblk->max_write_pgs);
+	if (!bio) {
+		pr_err("pblk: cannot allocate write bio\n");
+		goto fail_free_rqd;
+	}
+	bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+	rqd->bio = bio;
+
+	secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail, secs_to_flush);
+	if (secs_to_sync > pblk->max_write_pgs) {
+		pr_err("pblk: bad buffer sync calculation\n");
+		goto fail_put_bio;
+	}
+
+	secs_to_com = (secs_to_sync > secs_avail) ? secs_avail : secs_to_sync;
+	pos = pblk_rb_read_commit(&pblk->rwb, secs_to_com);
+
+	pgs_read = pblk_rb_read_to_bio(&pblk->rwb, bio, c_ctx, pos,
+						secs_to_sync, secs_avail);
+	if (!pgs_read) {
+		pr_err("pblk: corrupted write bio\n");
+		goto fail_put_bio;
+	}
+
+	if (c_ctx->nr_padded)
+		if (pblk_bio_add_pages(pblk, bio, GFP_KERNEL, c_ctx->nr_padded))
+			goto fail_put_bio;
+
+	/* Assign lbas to ppas and populate request structure */
+	err = pblk_setup_w_rq(pblk, rqd, c_ctx);
+	if (err) {
+		pr_err("pblk: could not setup write request\n");
+		goto fail_free_bio;
+	}
+
+	err = pblk_submit_io(pblk, rqd);
+	if (err) {
+		pr_err("pblk: I/O submission failed: %d\n", err);
+		goto fail_free_bio;
+	}
+
+#ifdef CONFIG_NVM_DEBUG
+	atomic_long_add(secs_to_sync, &pblk->sub_writes);
+#endif
+
+	return 0;
+
+fail_free_bio:
+	if (c_ctx->nr_padded)
+		pblk_bio_free_pages(pblk, bio, secs_to_sync, c_ctx->nr_padded);
+fail_put_bio:
+	bio_put(bio);
+fail_free_rqd:
+	pblk_free_rqd(pblk, rqd, WRITE);
+
+	return 1;
+}
+
+int pblk_write_ts(void *data)
+{
+	struct pblk *pblk = data;
+
+	while (!kthread_should_stop()) {
+		if (!pblk_submit_write(pblk))
+			continue;
+		set_current_state(TASK_INTERRUPTIBLE);
+		io_schedule();
+	}
+
+	return 0;
+}