[PATCH v9 2/5] gennvm: Generic NVM manager
Matias Bjørling
m at bjorling.me
Wed Oct 14 07:42:15 PDT 2015
The implementation for Open-Channel SSDs is divided into media
management and targets. This patch implements a generic media manager
for open-channel SSDs. After a media manager has been initialized,
single or multiple targets can be instantiated with the media managed as
the backend.
Signed-off-by: Matias Bjørling <m at bjorling.me>
---
drivers/lightnvm/Kconfig | 7 +
drivers/lightnvm/Makefile | 1 +
drivers/lightnvm/gennvm.c | 467 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/lightnvm/gennvm.h | 46 +++++
4 files changed, 521 insertions(+)
create mode 100644 drivers/lightnvm/gennvm.c
create mode 100644 drivers/lightnvm/gennvm.h
diff --git a/drivers/lightnvm/Kconfig b/drivers/lightnvm/Kconfig
index d4f309f..2a27971 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_GENNVM
+ tristate "Generic NVM manager for Open-Channel SSDs"
+ ---help---
+ NVM media manager for Open-Channel SSDs that offload management
+ functionality to 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..e2428e0 100644
--- a/drivers/lightnvm/Makefile
+++ b/drivers/lightnvm/Makefile
@@ -3,3 +3,4 @@
#
obj-$(CONFIG_NVM) := core.o
+obj-$(CONFIG_NVM_GENNVM) += gennvm.o
diff --git a/drivers/lightnvm/gennvm.c b/drivers/lightnvm/gennvm.c
new file mode 100644
index 0000000..b12c1b2
--- /dev/null
+++ b/drivers/lightnvm/gennvm.c
@@ -0,0 +1,467 @@
+/*
+ * 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 generic nvm manager for Open-Channel SSDs.
+ */
+
+#include "gennvm.h"
+
+static void gennvm_blocks_free(struct nvm_dev *dev)
+{
+ struct gen_nvm *gn = dev->mp;
+ struct gen_lun *lun;
+ int i;
+
+ gennvm_for_each_lun(gn, lun, i) {
+ if (!lun->vlun.blocks)
+ break;
+ vfree(lun->vlun.blocks);
+ }
+}
+
+static void gennvm_luns_free(struct nvm_dev *dev)
+{
+ struct gen_nvm *gn = dev->mp;
+
+ kfree(gn->luns);
+}
+
+static int gennvm_luns_init(struct nvm_dev *dev, struct gen_nvm *gn)
+{
+ struct gen_lun *lun;
+ int i;
+
+ gn->luns = kcalloc(dev->nr_luns, sizeof(struct gen_lun), GFP_KERNEL);
+ if (!gn->luns)
+ return -ENOMEM;
+
+ gennvm_for_each_lun(gn, lun, i) {
+ 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->reserved_blocks = 2; /* for GC only */
+ lun->vlun.id = i;
+ lun->vlun.lun_id = i % dev->luns_per_chnl;
+ lun->vlun.chnl_id = i / dev->luns_per_chnl;
+ lun->vlun.nr_free_blocks = dev->blks_per_lun;
+ }
+ return 0;
+}
+
+static int gennvm_block_bb(u32 lun_id, void *bb_bitmap, unsigned int nr_blocks,
+ void *private)
+{
+ struct gen_nvm *gn = private;
+ struct gen_lun *lun = &gn->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("gen_nvm: BB data is out of bounds.\n");
+ return -EINVAL;
+ }
+ list_move_tail(&block->list, &lun->bb_list);
+ }
+
+ return 0;
+}
+
+static int gennvm_block_map(u64 slba, u64 nlb, u64 *entries, void *private)
+{
+ struct nvm_dev *dev = private;
+ struct gen_nvm *gn = dev->mp;
+ sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
+ u64 elba = slba + nlb;
+ struct gen_lun *lun;
+ struct nvm_block *blk;
+ u64 i;
+ int lun_id;
+
+ if (unlikely(elba > dev->total_pages)) {
+ pr_err("gen_nvm: 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("gen_nvm: L2P data entry is out of bounds!\n");
+ return -EINVAL;
+ }
+
+ /* Address zero is a special one. The first page on a disk is
+ * protected. It often holds internal device boot
+ * information.
+ */
+ if (!pba)
+ continue;
+
+ /* resolve block from physical address */
+ lun_id = pba / dev->sec_per_lun;
+ lun = &gn->luns[lun_id];
+
+ /* Calculate block offset into lun */
+ pba = pba - (dev->sec_per_lun * lun_id);
+ blk = &lun->vlun.blocks[pba / dev->sec_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 gennvm_blocks_init(struct nvm_dev *dev, struct gen_nvm *gn)
+{
+ struct gen_lun *lun;
+ struct nvm_block *block;
+ sector_t lun_iter, blk_iter, cur_block_id = 0;
+ int ret;
+
+ gennvm_for_each_lun(gn, lun, lun_iter) {
+ lun->vlun.blocks = vzalloc(sizeof(struct nvm_block) *
+ dev->blks_per_lun);
+ if (!lun->vlun.blocks)
+ return -ENOMEM;
+
+ for (blk_iter = 0; blk_iter < dev->blks_per_lun; 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,
+ dev->blks_per_lun, gennvm_block_bb, gn);
+ if (ret)
+ pr_err("gen_nvm: could not read BB table\n");
+ }
+ }
+
+ if (dev->ops->get_l2p_tbl) {
+ ret = dev->ops->get_l2p_tbl(dev->q, 0, dev->total_pages,
+ gennvm_block_map, dev);
+ if (ret) {
+ pr_err("gen_nvm: could not read L2P table.\n");
+ pr_warn("gen_nvm: default block initialization");
+ }
+ }
+
+ return 0;
+}
+
+static int gennvm_register(struct nvm_dev *dev)
+{
+ struct gen_nvm *gn;
+ int ret;
+
+ if (!(dev->features.rsp & NVM_RSP_L2P))
+ return 0;
+
+ gn = kzalloc(sizeof(struct gen_nvm), GFP_KERNEL);
+ if (!gn)
+ return -ENOMEM;
+
+ gn->nr_luns = dev->nr_luns;
+ dev->mp = gn;
+
+ ret = gennvm_luns_init(dev, gn);
+ if (ret) {
+ pr_err("gen_nvm: could not initialize luns\n");
+ goto err;
+ }
+
+ ret = gennvm_blocks_init(dev, gn);
+ if (ret) {
+ pr_err("gen_nvm: could not initialize blocks\n");
+ goto err;
+ }
+
+ return 1;
+err:
+ kfree(gn);
+ return ret;
+}
+
+static void gennvm_unregister(struct nvm_dev *dev)
+{
+ gennvm_blocks_free(dev);
+ gennvm_luns_free(dev);
+ kfree(dev->mp);
+ dev->mp = NULL;
+}
+
+static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
+ struct nvm_lun *vlun, unsigned long flags)
+{
+ struct gen_lun *lun = container_of(vlun, struct gen_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("gen_nvm: 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);
+ blk->type = 1;
+
+ lun->vlun.nr_free_blocks--;
+
+ spin_unlock(&vlun->lock);
+out:
+ return blk;
+}
+
+static void gennvm_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
+{
+ struct nvm_lun *vlun = blk->lun;
+ struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
+
+ spin_lock(&vlun->lock);
+
+ switch (blk->type) {
+ case 1:
+ list_move_tail(&blk->list, &lun->free_list);
+ lun->vlun.nr_free_blocks++;
+ blk->type = 0;
+ break;
+ case 2:
+ list_move_tail(&blk->list, &lun->bb_list);
+ break;
+ default:
+ BUG();
+ }
+
+ spin_unlock(&vlun->lock);
+}
+
+static void gennvm_addr_to_generic_mode(struct nvm_dev *dev, struct nvm_rq *rqd)
+{
+ int i;
+
+ if (rqd->nr_pages > 1)
+ for (i = 0; i < rqd->nr_pages; i++)
+ rqd->ppa_list[i] = addr_to_generic_mode(dev,
+ rqd->ppa_list[i]);
+ else
+ rqd->ppa_addr = addr_to_generic_mode(dev, rqd->ppa_addr);
+}
+
+static void gennvm_generic_to_addr_mode(struct nvm_dev *dev, struct nvm_rq *rqd)
+{
+ int i;
+
+ if (rqd->nr_pages > 1)
+ for (i = 0; i < rqd->nr_pages; i++)
+ rqd->ppa_list[i] = generic_to_addr_mode(dev,
+ rqd->ppa_list[i]);
+ else
+ rqd->ppa_addr = generic_to_addr_mode(dev, rqd->ppa_addr);
+}
+
+static int gennvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
+{
+ if (!dev->ops->submit_io)
+ return 0;
+
+ /* Convert address space */
+ gennvm_generic_to_addr_mode(dev, rqd);
+
+ rqd->dev = dev;
+ return dev->ops->submit_io(dev->q, rqd);
+}
+
+static void gennvm_blk_set_type(struct nvm_dev *dev, struct ppa_addr *ppa,
+ int type)
+{
+ struct gen_nvm *gn = dev->mp;
+ struct gen_lun *lun;
+ struct nvm_block *blk;
+
+ BUG_ON(ppa->g.ch > dev->nr_chnls);
+ BUG_ON(ppa->g.lun > dev->luns_per_chnl);
+ BUG_ON(ppa->g.blk > dev->blks_per_lun);
+
+ lun = &gn->luns[ppa->g.lun * ppa->g.ch];
+ blk = &lun->vlun.blocks[ppa->g.blk];
+
+ /* will be moved to bb list on put_blk from target */
+ blk->type = type;
+}
+
+/* mark block bad. It is expected the target recover from the error. */
+static void gennvm_mark_blk_bad(struct nvm_dev *dev, struct nvm_rq *rqd)
+{
+ int i;
+
+ if (!dev->ops->set_bb)
+ return;
+
+ if (dev->ops->set_bb(dev->q, rqd, 1))
+ return;
+
+ gennvm_addr_to_generic_mode(dev, rqd);
+
+ /* look up blocks and mark them as bad */
+ if (rqd->nr_pages > 1)
+ for (i = 0; i < rqd->nr_pages; i++)
+ gennvm_blk_set_type(dev, &rqd->ppa_list[i], 2);
+ else
+ gennvm_blk_set_type(dev, &rqd->ppa_addr, 2);
+}
+
+static void gennvm_end_io(struct nvm_rq *rqd, int error)
+{
+ struct nvm_tgt_instance *ins = rqd->ins;
+
+ if (error == NVM_RSP_ERR_FAILWRITE)
+ gennvm_mark_blk_bad(rqd->dev, rqd);
+
+ ins->tt->end_io(rqd, error);
+}
+
+static int gennvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk,
+ unsigned long flags)
+{
+ int plane_cnt = 0, pl_idx, ret;
+ struct ppa_addr addr;
+ struct nvm_rq rqd;
+
+ if (!dev->ops->erase_block)
+ return 0;
+
+ addr = block_to_ppa(dev, blk);
+
+ if (dev->plane_mode == NVM_PLANE_SINGLE) {
+ rqd.nr_pages = 1;
+ rqd.ppa_addr = addr;
+ } else {
+ plane_cnt = (1 << dev->plane_mode);
+ rqd.nr_pages = plane_cnt;
+
+ rqd.ppa_list = nvm_dev_dma_alloc(dev, GFP_KERNEL,
+ &rqd.dma_ppa_list);
+ if (!rqd.ppa_list) {
+ pr_err("gen_nvm: failed to allocate dma memory\n");
+ return -ENOMEM;
+ }
+
+ for (pl_idx = 0; pl_idx < plane_cnt; pl_idx++) {
+ addr.g.pl = pl_idx;
+ rqd.ppa_list[pl_idx] = addr;
+ }
+ }
+
+ gennvm_generic_to_addr_mode(dev, &rqd);
+
+ ret = dev->ops->erase_block(dev->q, &rqd);
+
+ if (plane_cnt)
+ nvm_dev_dma_free(dev, rqd.ppa_list, rqd.dma_ppa_list);
+
+ return ret;
+}
+
+static struct nvm_lun *gennvm_get_lun(struct nvm_dev *dev, int lunid)
+{
+ struct gen_nvm *gn = dev->mp;
+
+ return &gn->luns[lunid].vlun;
+}
+
+static void gennvm_free_blocks_print(struct nvm_dev *dev)
+{
+ struct gen_nvm *gn = dev->mp;
+ struct gen_lun *lun;
+ unsigned int i;
+
+ gennvm_for_each_lun(gn, lun, i)
+ pr_info("%s: lun%8u\t%u\n",
+ dev->name, i, lun->vlun.nr_free_blocks);
+}
+
+static struct nvmm_type gennvm = {
+ .name = "gennvm",
+ .version = {0, 1, 0},
+
+ .register_mgr = gennvm_register,
+ .unregister_mgr = gennvm_unregister,
+
+ .get_blk = gennvm_get_blk,
+ .put_blk = gennvm_put_blk,
+
+ .submit_io = gennvm_submit_io,
+ .end_io = gennvm_end_io,
+ .erase_blk = gennvm_erase_blk,
+
+ .get_lun = gennvm_get_lun,
+ .free_blocks_print = gennvm_free_blocks_print,
+};
+
+static int __init gennvm_module_init(void)
+{
+ return nvm_register_mgr(&gennvm);
+}
+
+static void gennvm_module_exit(void)
+{
+ nvm_unregister_mgr(&gennvm);
+}
+
+module_init(gennvm_module_init);
+module_exit(gennvm_module_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Block manager for Hybrid Open-Channel SSDs");
diff --git a/drivers/lightnvm/gennvm.h b/drivers/lightnvm/gennvm.h
new file mode 100644
index 0000000..d23bd35
--- /dev/null
+++ b/drivers/lightnvm/gennvm.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright: Matias Bjorling <mb 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.
+ *
+ */
+
+#ifndef GENNVM_H_
+#define GENNVM_H_
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+
+#include <linux/lightnvm.h>
+
+struct gen_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 gen_nvm {
+ int nr_luns;
+ struct gen_lun *luns;
+};
+
+#define gennvm_for_each_lun(bm, lun, i) \
+ for ((i) = 0, lun = &(bm)->luns[0]; \
+ (i) < (bm)->nr_luns; (i)++, lun = &(bm)->luns[(i)])
+
+#endif /* GENNVM_H_ */
--
2.1.4
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