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    Subject[PATCH v14 2/5] gennvm: Generic NVM manager
    Date
    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@bjorling.me>
    ---
    drivers/lightnvm/Kconfig | 7 +
    drivers/lightnvm/Makefile | 1 +
    drivers/lightnvm/gennvm.c | 485 ++++++++++++++++++++++++++++++++++++++++++++++
    drivers/lightnvm/gennvm.h | 46 +++++
    4 files changed, 539 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..ae1fb2b
    --- /dev/null
    +++ b/drivers/lightnvm/gennvm.c
    @@ -0,0 +1,485 @@
    +/*
    + * Copyright (C) 2015 Matias Bjorling <m@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 *blk;
    + 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) {
    + blk = &lun->vlun.blocks[i];
    + if (!blk) {
    + pr_err("gennvm: BB data is out of bounds.\n");
    + return -EINVAL;
    + }
    +
    + list_move_tail(&blk->list, &lun->bb_list);
    + }
    +
    + return 0;
    +}
    +
    +static int gennvm_block_map(u64 slba, u32 nlb, __le64 *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("gennvm: 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("gennvm: 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 = div_u64(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[div_u64(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("gennvm: 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("gennvm: could not read L2P table.\n");
    + pr_warn("gennvm: default block initialization");
    + }
    + }
    +
    + return 0;
    +}
    +
    +static int gennvm_register(struct nvm_dev *dev)
    +{
    + struct gen_nvm *gn;
    + int ret;
    +
    + 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("gennvm: could not initialize luns\n");
    + goto err;
    + }
    +
    + ret = gennvm_blocks_init(dev, gn);
    + if (ret) {
    + pr_err("gennvm: 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;
    +
    + spin_lock(&vlun->lock);
    +
    + if (list_empty(&lun->free_list)) {
    + pr_err_ratelimited("gennvm: 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:
    + WARN_ON_ONCE(1);
    + pr_err("gennvm: erroneous block type (%lu -> %u)\n",
    + blk->id, blk->type);
    + list_move_tail(&blk->list, &lun->bb_list);
    + }
    +
    + 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;
    +
    + if (unlikely(ppa->g.ch > dev->nr_chnls ||
    + ppa->g.lun > dev->luns_per_chnl ||
    + ppa->g.blk > dev->blks_per_lun)) {
    + WARN_ON_ONCE(1);
    + pr_err("gennvm: ppa broken (ch: %u > %u lun: %u > %u blk: %u > %u",
    + ppa->g.ch, dev->nr_chnls,
    + ppa->g.lun, dev->luns_per_chnl,
    + ppa->g.blk, dev->blks_per_lun);
    + return;
    + }
    +
    + 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 int gennvm_end_io(struct nvm_rq *rqd, int error)
    +{
    + struct nvm_tgt_instance *ins = rqd->ins;
    + int ret = 0;
    +
    + switch (error) {
    + case NVM_RSP_SUCCESS:
    + break;
    + case NVM_RSP_ERR_EMPTYPAGE:
    + break;
    + case NVM_RSP_ERR_FAILWRITE:
    + gennvm_mark_blk_bad(rqd->dev, rqd);
    + default:
    + ret++;
    + }
    +
    + ret += ins->tt->end_io(rqd, error);
    +
    + return ret;
    +}
    +
    +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("gennvm: 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("Generic media manager for 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@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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