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SubjectRe: [PATCH v13 2/5] gennvm: Generic NVM manager
On 10/28/2015 08:30 AM, Matias Bjørling wrote:
> The implementation for Open-Channel SSDs is divided into media
[...]
> + 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;

Please use do_div(). % would be not supported in some platforms, as
the kbuild pointed in V12.

Yang

> + 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, 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("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 = 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("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;
> +
> + 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 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("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@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_ */
>



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