[PATCH v8 2/5] lightnvm: Hybrid Open-Channel SSD block manager
Matias Bjørling
m at bjorling.me
Mon Sep 21 09:05:47 PDT 2015
The host implementation for Open-Channel SSDs is divided into block
management and targets. This patch implements a basic block manager
hybrid open-channel SSDs. On top of the block manager, a target can
be initialized.
Signed-off-by: Matias Bjørling <m at bjorling.me>
---
drivers/lightnvm/Kconfig | 7 +
drivers/lightnvm/Makefile | 1 +
drivers/lightnvm/bm_hb.c | 372 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/lightnvm/bm_hb.h | 46 ++++++
4 files changed, 426 insertions(+)
create mode 100644 drivers/lightnvm/bm_hb.c
create mode 100644 drivers/lightnvm/bm_hb.h
diff --git a/drivers/lightnvm/Kconfig b/drivers/lightnvm/Kconfig
index d4f309f..15e507a 100644
--- a/drivers/lightnvm/Kconfig
+++ b/drivers/lightnvm/Kconfig
@@ -25,4 +25,11 @@ config NVM_DEBUG
It is required to create/remove targets without IOCTLs.
+config NVM_BM_HB
+ tristate "Block manager for Hybrid Open-Channel SSD"
+ ---help---
+ Block manager for SSDs that offload block management off to the device,
+ while keeping data placement and garbage collection decisions on the
+ host.
+
endif # NVM
diff --git a/drivers/lightnvm/Makefile b/drivers/lightnvm/Makefile
index 38185e9..5228f83 100644
--- a/drivers/lightnvm/Makefile
+++ b/drivers/lightnvm/Makefile
@@ -3,3 +3,4 @@
#
obj-$(CONFIG_NVM) := core.o
+obj-$(CONFIG_NVM_BM_HB) += bm_hb.o
diff --git a/drivers/lightnvm/bm_hb.c b/drivers/lightnvm/bm_hb.c
new file mode 100644
index 0000000..22c6db7
--- /dev/null
+++ b/drivers/lightnvm/bm_hb.c
@@ -0,0 +1,372 @@
+/*
+ * Copyright (C) 2015 Matias Bjorling <m at bjorling.me>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ * Implementation of a block manager for hybrid open-channel SSD.
+ */
+
+#include "bm_hb.h"
+
+static void hb_blocks_free(struct nvm_dev *dev)
+{
+ struct bm_hb *bm = dev->bmp;
+ struct bm_lun *lun;
+ int i;
+
+ bm_for_each_lun(bm, lun, i) {
+ if (!lun->vlun.blocks)
+ break;
+ vfree(lun->vlun.blocks);
+ }
+}
+
+static void hb_luns_free(struct nvm_dev *dev)
+{
+ struct bm_hb *bm = dev->bmp;
+
+ kfree(bm->luns);
+}
+
+static int hb_luns_init(struct nvm_dev *dev, struct bm_hb *bm)
+{
+ struct bm_lun *lun;
+ struct nvm_id_chnl *chnl;
+ int i;
+
+ bm->luns = kcalloc(bm->nr_luns, sizeof(struct bm_lun), GFP_KERNEL);
+ if (!bm->luns)
+ return -ENOMEM;
+
+ bm_for_each_lun(bm, lun, i) {
+ chnl = &dev->identity.chnls[i];
+ pr_info("bm_hb: p %u qsize %u gr %u ge %u begin %llu end %llu\n",
+ i, chnl->queue_size, chnl->gran_read, chnl->gran_erase,
+ chnl->laddr_begin, chnl->laddr_end);
+
+ spin_lock_init(&lun->vlun.lock);
+
+ INIT_LIST_HEAD(&lun->free_list);
+ INIT_LIST_HEAD(&lun->used_list);
+ INIT_LIST_HEAD(&lun->bb_list);
+
+ lun->vlun.id = i;
+ lun->chnl = chnl;
+ lun->reserved_blocks = 2; /* for GC only */
+ lun->vlun.nr_blocks =
+ (chnl->laddr_end - chnl->laddr_begin + 1) /
+ (chnl->gran_erase / chnl->gran_read);
+ lun->vlun.nr_free_blocks = lun->vlun.nr_blocks;
+ lun->vlun.nr_pages_per_blk =
+ chnl->gran_erase / chnl->gran_write *
+ (chnl->gran_write / dev->sector_size);
+
+ if (lun->vlun.nr_pages_per_blk > dev->max_pages_per_blk)
+ dev->max_pages_per_blk = lun->vlun.nr_pages_per_blk;
+
+ dev->total_pages += lun->vlun.nr_blocks *
+ lun->vlun.nr_pages_per_blk;
+ dev->total_blocks += lun->vlun.nr_blocks;
+ }
+
+ return 0;
+}
+
+static int hb_block_bb(u32 lun_id, void *bb_bitmap, unsigned int nr_blocks,
+ void *private)
+{
+ struct bm_hb *bm = private;
+ struct bm_lun *lun = &bm->luns[lun_id];
+ struct nvm_block *block;
+ int i;
+
+ if (unlikely(bitmap_empty(bb_bitmap, nr_blocks)))
+ return 0;
+
+ i = -1;
+ while ((i = find_next_bit(bb_bitmap, nr_blocks, i + 1)) <
+ nr_blocks) {
+ block = &lun->vlun.blocks[i];
+ if (!block) {
+ pr_err("bm_hb: BB data is out of bounds!\n");
+ return -EINVAL;
+ }
+ list_move_tail(&block->list, &lun->bb_list);
+ }
+
+ return 0;
+}
+
+static int hb_block_map(u64 slba, u64 nlb, u64 *entries, void *private)
+{
+ struct nvm_dev *dev = private;
+ struct bm_hb *bm = dev->bmp;
+ sector_t max_pages = dev->total_pages * (dev->sector_size >> 9);
+ u64 elba = slba + nlb;
+ struct bm_lun *lun;
+ struct nvm_block *blk;
+ sector_t total_pgs_per_lun = /* each lun have the same configuration */
+ bm->luns[0].vlun.nr_blocks * bm->luns[0].vlun.nr_pages_per_blk;
+ u64 i;
+ int lun_id;
+
+ if (unlikely(elba > dev->total_pages)) {
+ pr_err("bm_hb: L2P data from device is out of bounds!\n");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < nlb; i++) {
+ u64 pba = le64_to_cpu(entries[i]);
+
+ if (unlikely(pba >= max_pages && pba != U64_MAX)) {
+ pr_err("bm_hb: L2P data entry is out of bounds!\n");
+ return -EINVAL;
+ }
+
+ /* Address zero is a special one. The first page on a disk is
+ * protected. As it often holds internal device boot
+ * information. */
+ if (!pba)
+ continue;
+
+ /* resolve block from physical address */
+ lun_id = pba / total_pgs_per_lun;
+ lun = &bm->luns[lun_id];
+
+ /* Calculate block offset into lun */
+ pba = pba - (total_pgs_per_lun * lun_id);
+ blk = &lun->vlun.blocks[pba / lun->vlun.nr_pages_per_blk];
+
+ if (!blk->type) {
+ /* at this point, we don't know anything about the
+ * block. It's up to the FTL on top to re-etablish the
+ * block state */
+ list_move_tail(&blk->list, &lun->used_list);
+ blk->type = 1;
+ lun->vlun.nr_free_blocks--;
+ }
+ }
+
+ return 0;
+}
+
+static int hb_blocks_init(struct nvm_dev *dev, struct bm_hb *bm)
+{
+ struct bm_lun *lun;
+ struct nvm_block *block;
+ sector_t lun_iter, blk_iter, cur_block_id = 0;
+ int ret;
+
+ bm_for_each_lun(bm, lun, lun_iter) {
+ lun->vlun.blocks = vzalloc(sizeof(struct nvm_block) *
+ lun->vlun.nr_blocks);
+ if (!lun->vlun.blocks)
+ return -ENOMEM;
+
+ for (blk_iter = 0; blk_iter < lun->vlun.nr_blocks; blk_iter++) {
+ block = &lun->vlun.blocks[blk_iter];
+
+ INIT_LIST_HEAD(&block->list);
+
+ block->lun = &lun->vlun;
+ block->id = cur_block_id++;
+
+ /* First block is reserved for device */
+ if (unlikely(lun_iter == 0 && blk_iter == 0))
+ continue;
+
+ list_add_tail(&block->list, &lun->free_list);
+ }
+
+ if (dev->ops->get_bb_tbl) {
+ ret = dev->ops->get_bb_tbl(dev->q, lun->vlun.id,
+ lun->vlun.nr_blocks, hb_block_bb, bm);
+ if (ret)
+ pr_err("bm_hb: could not read BB table\n");
+ }
+ }
+
+ if (dev->ops->get_l2p_tbl) {
+ ret = dev->ops->get_l2p_tbl(dev->q, 0, dev->total_pages,
+ hb_block_map, dev);
+ if (ret) {
+ pr_err("bm_hb: could not read L2P table.\n");
+ pr_warn("bm_hb: default block initialization");
+ }
+ }
+
+ return 0;
+}
+
+static int hb_register(struct nvm_dev *dev)
+{
+ struct bm_hb *bm;
+ int ret;
+
+ if (!(dev->features.rsp & NVM_RSP_L2P))
+ return 0;
+
+ bm = kzalloc(sizeof(struct bm_hb), GFP_KERNEL);
+ if (!bm)
+ return -ENOMEM;
+
+ bm->nr_luns = dev->nr_luns;
+ dev->bmp = bm;
+
+ ret = hb_luns_init(dev, bm);
+ if (ret) {
+ pr_err("bm_hb: could not initialize luns\n");
+ goto err;
+ }
+
+ ret = hb_blocks_init(dev, bm);
+ if (ret) {
+ pr_err("bm_hb: could not initialize blocks\n");
+ goto err;
+ }
+
+ return 1;
+err:
+ kfree(bm);
+ return ret;
+}
+
+static void hb_unregister(struct nvm_dev *dev)
+{
+ hb_blocks_free(dev);
+ hb_luns_free(dev);
+ kfree(dev->bmp);
+ dev->bmp = NULL;
+}
+
+static struct nvm_block *hb_get_blk(struct nvm_dev *dev, struct nvm_lun *vlun,
+ unsigned long flags)
+{
+ struct bm_lun *lun = container_of(vlun, struct bm_lun, vlun);
+ struct nvm_block *blk = NULL;
+ int is_gc = flags & NVM_IOTYPE_GC;
+
+ BUG_ON(!lun);
+
+ spin_lock(&vlun->lock);
+
+ if (list_empty(&lun->free_list)) {
+ pr_err_ratelimited("bm_hb: lun %u have no free pages available",
+ lun->vlun.id);
+ spin_unlock(&vlun->lock);
+ goto out;
+ }
+
+ while (!is_gc && lun->vlun.nr_free_blocks < lun->reserved_blocks) {
+ spin_unlock(&vlun->lock);
+ goto out;
+ }
+
+ blk = list_first_entry(&lun->free_list, struct nvm_block, list);
+ list_move_tail(&blk->list, &lun->used_list);
+
+ lun->vlun.nr_free_blocks--;
+
+ spin_unlock(&vlun->lock);
+out:
+ return blk;
+}
+
+static void hb_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
+{
+ struct nvm_lun *vlun = blk->lun;
+ struct bm_lun *lun = container_of(vlun, struct bm_lun, vlun);
+
+ spin_lock(&vlun->lock);
+
+ list_move_tail(&blk->list, &lun->free_list);
+ lun->vlun.nr_free_blocks++;
+
+ spin_unlock(&vlun->lock);
+}
+
+static int hb_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
+{
+ if (!dev->ops->submit_io)
+ return 0;
+
+ return dev->ops->submit_io(dev->q, rqd);
+}
+
+static void hb_end_io(struct nvm_rq *rqd, int error)
+{
+ struct nvm_tgt_instance *ins = rqd->ins;
+
+ ins->tt->end_io(rqd, error);
+}
+
+static int hb_erase_blk(struct nvm_dev *dev, struct nvm_block *blk)
+{
+ if (!dev->ops->erase_block)
+ return 0;
+
+ return dev->ops->erase_block(dev->q, blk->id);
+}
+
+static struct nvm_lun *hb_get_luns(struct nvm_dev *dev, int begin, int end)
+{
+ struct bm_hb *bm = dev->bmp;
+
+ return &bm->luns[begin].vlun;
+}
+
+static void hb_free_blocks_print(struct nvm_dev *dev)
+{
+ struct bm_hb *bm = dev->bmp;
+ struct bm_lun *lun;
+ unsigned int i;
+
+ bm_for_each_lun(bm, lun, i)
+ pr_info("%s: lun%8u\t%u\n",
+ dev->name, i, lun->vlun.nr_free_blocks);
+}
+
+static struct nvm_bm_type bm_hb = {
+ .name = "hb",
+ .version = {0, 1, 0},
+
+ .register_bm = hb_register,
+ .unregister_bm = hb_unregister,
+
+ .get_blk = hb_get_blk,
+ .put_blk = hb_put_blk,
+
+ .submit_io = hb_submit_io,
+ .end_io = hb_end_io,
+ .erase_blk = hb_erase_blk,
+
+ .get_luns = hb_get_luns,
+ .free_blocks_print = hb_free_blocks_print,
+};
+
+static int __init hb_module_init(void)
+{
+ return nvm_register_bm(&bm_hb);
+}
+
+static void hb_module_exit(void)
+{
+ nvm_unregister_bm(&bm_hb);
+}
+
+module_init(hb_module_init);
+module_exit(hb_module_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Block manager for Hybrid Open-Channel SSDs");
diff --git a/drivers/lightnvm/bm_hb.h b/drivers/lightnvm/bm_hb.h
new file mode 100644
index 0000000..b856a70
--- /dev/null
+++ b/drivers/lightnvm/bm_hb.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright: Matias Bjorling <mb at lightnvm.io>
+ *
+ * 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.
+ *
+ */
+
+#ifndef BM_HB_H_
+#define BM_HB_H_
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+
+#include <linux/lightnvm.h>
+
+struct bm_lun {
+ struct nvm_lun vlun;
+
+ int reserved_blocks;
+ /* lun block lists */
+ struct list_head used_list; /* In-use blocks */
+ struct list_head free_list; /* Not used blocks i.e. released
+ * and ready for use */
+ struct list_head bb_list; /* Bad blocks. Mutually exclusive with
+ free_list and used_list */
+
+ struct nvm_id_chnl *chnl;
+};
+
+struct bm_hb {
+ int nr_luns;
+ struct bm_lun *luns;
+};
+
+#define bm_for_each_lun(bm, lun, i) \
+ for ((i) = 0, lun = &(bm)->luns[0]; \
+ (i) < (bm)->nr_luns; (i)++, lun = &(bm)->luns[(i)])
+
+#endif /* BM_HB_H_ */
--
2.1.4
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