1 files changed, 562 insertions, 0 deletions

diff --git a/drivers/lightnvm/sysblk.c b/drivers/lightnvm/sysblk.c
new file mode 100644
index 000000000000..b8489f425b05
--- /dev/null
+++ b/drivers/lightnvm/sysblk.c
@@ -0,0 +1,562 @@
+/*
+ * Copyright (C) 2015 Matias Bjorling. All rights reserved.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/lightnvm.h>
+
+#define MAX_SYSBLKS 3	/* remember to update mapping scheme on change */
+#define MAX_BLKS_PR_SYSBLK 2 /* 2 blks with 256 pages and 3000 erases
+			      * enables ~1.5M updates per sysblk unit
+			      */
+
+struct sysblk_scan {
+	/* A row is a collection of flash blocks for a system block. */
+	int nr_rows;
+	int row;
+	int act_blk[MAX_SYSBLKS];
+
+	int nr_ppas;
+	struct ppa_addr ppas[MAX_SYSBLKS * MAX_BLKS_PR_SYSBLK];/* all sysblks */
+};
+
+static inline int scan_ppa_idx(int row, int blkid)
+{
+	return (row * MAX_BLKS_PR_SYSBLK) + blkid;
+}
+
+void nvm_sysblk_to_cpu(struct nvm_sb_info *info, struct nvm_system_block *sb)
+{
+	info->seqnr = be32_to_cpu(sb->seqnr);
+	info->erase_cnt = be32_to_cpu(sb->erase_cnt);
+	info->version = be16_to_cpu(sb->version);
+	strncpy(info->mmtype, sb->mmtype, NVM_MMTYPE_LEN);
+	info->fs_ppa.ppa = be64_to_cpu(sb->fs_ppa);
+}
+
+void nvm_cpu_to_sysblk(struct nvm_system_block *sb, struct nvm_sb_info *info)
+{
+	sb->magic = cpu_to_be32(NVM_SYSBLK_MAGIC);
+	sb->seqnr = cpu_to_be32(info->seqnr);
+	sb->erase_cnt = cpu_to_be32(info->erase_cnt);
+	sb->version = cpu_to_be16(info->version);
+	strncpy(sb->mmtype, info->mmtype, NVM_MMTYPE_LEN);
+	sb->fs_ppa = cpu_to_be64(info->fs_ppa.ppa);
+}
+
+static int nvm_setup_sysblks(struct nvm_dev *dev, struct ppa_addr *sysblk_ppas)
+{
+	int nr_rows = min_t(int, MAX_SYSBLKS, dev->nr_chnls);
+	int i;
+
+	for (i = 0; i < nr_rows; i++)
+		sysblk_ppas[i].ppa = 0;
+
+	/* if possible, place sysblk at first channel, middle channel and last
+	 * channel of the device. If not, create only one or two sys blocks
+	 */
+	switch (dev->nr_chnls) {
+	case 2:
+		sysblk_ppas[1].g.ch = 1;
+		/* fall-through */
+	case 1:
+		sysblk_ppas[0].g.ch = 0;
+		break;
+	default:
+		sysblk_ppas[0].g.ch = 0;
+		sysblk_ppas[1].g.ch = dev->nr_chnls / 2;
+		sysblk_ppas[2].g.ch = dev->nr_chnls - 1;
+		break;
+	}
+
+	return nr_rows;
+}
+
+void nvm_setup_sysblk_scan(struct nvm_dev *dev, struct sysblk_scan *s,
+						struct ppa_addr *sysblk_ppas)
+{
+	memset(s, 0, sizeof(struct sysblk_scan));
+	s->nr_rows = nvm_setup_sysblks(dev, sysblk_ppas);
+}
+
+static int sysblk_get_host_blks(struct ppa_addr ppa, int nr_blks, u8 *blks,
+								void *private)
+{
+	struct sysblk_scan *s = private;
+	int i, nr_sysblk = 0;
+
+	for (i = 0; i < nr_blks; i++) {
+		if (blks[i] != NVM_BLK_T_HOST)
+			continue;
+
+		if (s->nr_ppas == MAX_BLKS_PR_SYSBLK * MAX_SYSBLKS) {
+			pr_err("nvm: too many host blks\n");
+			return -EINVAL;
+		}
+
+		ppa.g.blk = i;
+
+		s->ppas[scan_ppa_idx(s->row, nr_sysblk)] = ppa;
+		s->nr_ppas++;
+		nr_sysblk++;
+	}
+
+	return 0;
+}
+
+static int nvm_get_all_sysblks(struct nvm_dev *dev, struct sysblk_scan *s,
+				struct ppa_addr *ppas, nvm_bb_update_fn *fn)
+{
+	struct ppa_addr dppa;
+	int i, ret;
+
+	s->nr_ppas = 0;
+
+	for (i = 0; i < s->nr_rows; i++) {
+		dppa = generic_to_dev_addr(dev, ppas[i]);
+		s->row = i;
+
+		ret = dev->ops->get_bb_tbl(dev, dppa, dev->blks_per_lun, fn, s);
+		if (ret) {
+			pr_err("nvm: failed bb tbl for ppa (%u %u)\n",
+							ppas[i].g.ch,
+							ppas[i].g.blk);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * scans a block for latest sysblk.
+ * Returns:
+ *	0 - newer sysblk not found. PPA is updated to latest page.
+ *	1 - newer sysblk found and stored in *cur. PPA is updated to
+ *	    next valid page.
+ *	<0- error.
+ */
+static int nvm_scan_block(struct nvm_dev *dev, struct ppa_addr *ppa,
+						struct nvm_system_block *sblk)
+{
+	struct nvm_system_block *cur;
+	int pg, cursz, ret, found = 0;
+
+	/* the full buffer for a flash page is allocated. Only the first of it
+	 * contains the system block information
+	 */
+	cursz = dev->sec_size * dev->sec_per_pg * dev->nr_planes;
+	cur = kmalloc(cursz, GFP_KERNEL);
+	if (!cur)
+		return -ENOMEM;
+
+	/* perform linear scan through the block */
+	for (pg = 0; pg < dev->lps_per_blk; pg++) {
+		ppa->g.pg = ppa_to_slc(dev, pg);
+
+		ret = nvm_submit_ppa(dev, ppa, 1, NVM_OP_PREAD, NVM_IO_SLC_MODE,
+								cur, cursz);
+		if (ret) {
+			if (ret == NVM_RSP_ERR_EMPTYPAGE) {
+				pr_debug("nvm: sysblk scan empty ppa (%u %u %u %u)\n",
+							ppa->g.ch,
+							ppa->g.lun,
+							ppa->g.blk,
+							ppa->g.pg);
+				break;
+			}
+			pr_err("nvm: read failed (%x) for ppa (%u %u %u %u)",
+							ret,
+							ppa->g.ch,
+							ppa->g.lun,
+							ppa->g.blk,
+							ppa->g.pg);
+			break; /* if we can't read a page, continue to the
+				* next blk
+				*/
+		}
+
+		if (be32_to_cpu(cur->magic) != NVM_SYSBLK_MAGIC) {
+			pr_debug("nvm: scan break for ppa (%u %u %u %u)\n",
+							ppa->g.ch,
+							ppa->g.lun,
+							ppa->g.blk,
+							ppa->g.pg);
+			break; /* last valid page already found */
+		}
+
+		if (be32_to_cpu(cur->seqnr) < be32_to_cpu(sblk->seqnr))
+			continue;
+
+		memcpy(sblk, cur, sizeof(struct nvm_system_block));
+		found = 1;
+	}
+
+	kfree(cur);
+
+	return found;
+}
+
+static int nvm_set_bb_tbl(struct nvm_dev *dev, struct sysblk_scan *s, int type)
+{
+	struct nvm_rq rqd;
+	int ret;
+
+	if (s->nr_ppas > dev->ops->max_phys_sect) {
+		pr_err("nvm: unable to update all sysblocks atomically\n");
+		return -EINVAL;
+	}
+
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+
+	nvm_set_rqd_ppalist(dev, &rqd, s->ppas, s->nr_ppas);
+	nvm_generic_to_addr_mode(dev, &rqd);
+
+	ret = dev->ops->set_bb_tbl(dev, &rqd, type);
+	nvm_free_rqd_ppalist(dev, &rqd);
+	if (ret) {
+		pr_err("nvm: sysblk failed bb mark\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int sysblk_get_free_blks(struct ppa_addr ppa, int nr_blks, u8 *blks,
+								void *private)
+{
+	struct sysblk_scan *s = private;
+	struct ppa_addr *sppa;
+	int i, blkid = 0;
+
+	for (i = 0; i < nr_blks; i++) {
+		if (blks[i] == NVM_BLK_T_HOST)
+			return -EEXIST;
+
+		if (blks[i] != NVM_BLK_T_FREE)
+			continue;
+
+		sppa = &s->ppas[scan_ppa_idx(s->row, blkid)];
+		sppa->g.ch = ppa.g.ch;
+		sppa->g.lun = ppa.g.lun;
+		sppa->g.blk = i;
+		s->nr_ppas++;
+		blkid++;
+
+		pr_debug("nvm: use (%u %u %u) as sysblk\n",
+					sppa->g.ch, sppa->g.lun, sppa->g.blk);
+		if (blkid > MAX_BLKS_PR_SYSBLK - 1)
+			return 0;
+	}
+
+	pr_err("nvm: sysblk failed get sysblk\n");
+	return -EINVAL;
+}
+
+static int nvm_write_and_verify(struct nvm_dev *dev, struct nvm_sb_info *info,
+							struct sysblk_scan *s)
+{
+	struct nvm_system_block nvmsb;
+	void *buf;
+	int i, sect, ret, bufsz;
+	struct ppa_addr *ppas;
+
+	nvm_cpu_to_sysblk(&nvmsb, info);
+
+	/* buffer for flash page */
+	bufsz = dev->sec_size * dev->sec_per_pg * dev->nr_planes;
+	buf = kzalloc(bufsz, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	memcpy(buf, &nvmsb, sizeof(struct nvm_system_block));
+
+	ppas = kcalloc(dev->sec_per_pg, sizeof(struct ppa_addr), GFP_KERNEL);
+	if (!ppas) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	/* Write and verify */
+	for (i = 0; i < s->nr_rows; i++) {
+		ppas[0] = s->ppas[scan_ppa_idx(i, s->act_blk[i])];
+
+		pr_debug("nvm: writing sysblk to ppa (%u %u %u %u)\n",
+							ppas[0].g.ch,
+							ppas[0].g.lun,
+							ppas[0].g.blk,
+							ppas[0].g.pg);
+
+		/* Expand to all sectors within a flash page */
+		if (dev->sec_per_pg > 1) {
+			for (sect = 1; sect < dev->sec_per_pg; sect++) {
+				ppas[sect].ppa = ppas[0].ppa;
+				ppas[sect].g.sec = sect;
+			}
+		}
+
+		ret = nvm_submit_ppa(dev, ppas, dev->sec_per_pg, NVM_OP_PWRITE,
+						NVM_IO_SLC_MODE, buf, bufsz);
+		if (ret) {
+			pr_err("nvm: sysblk failed program (%u %u %u)\n",
+							ppas[0].g.ch,
+							ppas[0].g.lun,
+							ppas[0].g.blk);
+			break;
+		}
+
+		ret = nvm_submit_ppa(dev, ppas, dev->sec_per_pg, NVM_OP_PREAD,
+						NVM_IO_SLC_MODE, buf, bufsz);
+		if (ret) {
+			pr_err("nvm: sysblk failed read (%u %u %u)\n",
+							ppas[0].g.ch,
+							ppas[0].g.lun,
+							ppas[0].g.blk);
+			break;
+		}
+
+		if (memcmp(buf, &nvmsb, sizeof(struct nvm_system_block))) {
+			pr_err("nvm: sysblk failed verify (%u %u %u)\n",
+							ppas[0].g.ch,
+							ppas[0].g.lun,
+							ppas[0].g.blk);
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	kfree(ppas);
+err:
+	kfree(buf);
+
+	return ret;
+}
+
+static int nvm_prepare_new_sysblks(struct nvm_dev *dev, struct sysblk_scan *s)
+{
+	int i, ret;
+	unsigned long nxt_blk;
+	struct ppa_addr *ppa;
+
+	for (i = 0; i < s->nr_rows; i++) {
+		nxt_blk = (s->act_blk[i] + 1) % MAX_BLKS_PR_SYSBLK;
+		ppa = &s->ppas[scan_ppa_idx(i, nxt_blk)];
+		ppa->g.pg = ppa_to_slc(dev, 0);
+
+		ret = nvm_erase_ppa(dev, ppa, 1);
+		if (ret)
+			return ret;
+
+		s->act_blk[i] = nxt_blk;
+	}
+
+	return 0;
+}
+
+int nvm_get_sysblock(struct nvm_dev *dev, struct nvm_sb_info *info)
+{
+	struct ppa_addr sysblk_ppas[MAX_SYSBLKS];
+	struct sysblk_scan s;
+	struct nvm_system_block *cur;
+	int i, j, found = 0;
+	int ret = -ENOMEM;
+
+	/*
+	 * 1. setup sysblk locations
+	 * 2. get bad block list
+	 * 3. filter on host-specific (type 3)
+	 * 4. iterate through all and find the highest seq nr.
+	 * 5. return superblock information
+	 */
+
+	if (!dev->ops->get_bb_tbl)
+		return -EINVAL;
+
+	nvm_setup_sysblk_scan(dev, &s, sysblk_ppas);
+
+	mutex_lock(&dev->mlock);
+	ret = nvm_get_all_sysblks(dev, &s, sysblk_ppas, sysblk_get_host_blks);
+	if (ret)
+		goto err_sysblk;
+
+	/* no sysblocks initialized */
+	if (!s.nr_ppas)
+		goto err_sysblk;
+
+	cur = kzalloc(sizeof(struct nvm_system_block), GFP_KERNEL);
+	if (!cur)
+		goto err_sysblk;
+
+	/* find the latest block across all sysblocks */
+	for (i = 0; i < s.nr_rows; i++) {
+		for (j = 0; j < MAX_BLKS_PR_SYSBLK; j++) {
+			struct ppa_addr ppa = s.ppas[scan_ppa_idx(i, j)];
+
+			ret = nvm_scan_block(dev, &ppa, cur);
+			if (ret > 0)
+				found = 1;
+			else if (ret < 0)
+				break;
+		}
+	}
+
+	nvm_sysblk_to_cpu(info, cur);
+
+	kfree(cur);
+err_sysblk:
+	mutex_unlock(&dev->mlock);
+
+	if (found)
+		return 1;
+	return ret;
+}
+
+int nvm_update_sysblock(struct nvm_dev *dev, struct nvm_sb_info *new)
+{
+	/* 1. for each latest superblock
+	 * 2. if room
+	 *    a. write new flash page entry with the updated information
+	 * 3. if no room
+	 *    a. find next available block on lun (linear search)
+	 *       if none, continue to next lun
+	 *       if none at all, report error. also report that it wasn't
+	 *       possible to write to all superblocks.
+	 *    c. write data to block.
+	 */
+	struct ppa_addr sysblk_ppas[MAX_SYSBLKS];
+	struct sysblk_scan s;
+	struct nvm_system_block *cur;
+	int i, j, ppaidx, found = 0;
+	int ret = -ENOMEM;
+
+	if (!dev->ops->get_bb_tbl)
+		return -EINVAL;
+
+	nvm_setup_sysblk_scan(dev, &s, sysblk_ppas);
+
+	mutex_lock(&dev->mlock);
+	ret = nvm_get_all_sysblks(dev, &s, sysblk_ppas, sysblk_get_host_blks);
+	if (ret)
+		goto err_sysblk;
+
+	cur = kzalloc(sizeof(struct nvm_system_block), GFP_KERNEL);
+	if (!cur)
+		goto err_sysblk;
+
+	/* Get the latest sysblk for each sysblk row */
+	for (i = 0; i < s.nr_rows; i++) {
+		found = 0;
+		for (j = 0; j < MAX_BLKS_PR_SYSBLK; j++) {
+			ppaidx = scan_ppa_idx(i, j);
+			ret = nvm_scan_block(dev, &s.ppas[ppaidx], cur);
+			if (ret > 0) {
+				s.act_blk[i] = j;
+				found = 1;
+			} else if (ret < 0)
+				break;
+		}
+	}
+
+	if (!found) {
+		pr_err("nvm: no valid sysblks found to update\n");
+		ret = -EINVAL;
+		goto err_cur;
+	}
+
+	/*
+	 * All sysblocks found. Check that they have same page id in their flash
+	 * blocks
+	 */
+	for (i = 1; i < s.nr_rows; i++) {
+		struct ppa_addr l = s.ppas[scan_ppa_idx(0, s.act_blk[0])];
+		struct ppa_addr r = s.ppas[scan_ppa_idx(i, s.act_blk[i])];
+
+		if (l.g.pg != r.g.pg) {
+			pr_err("nvm: sysblks not on same page. Previous update failed.\n");
+			ret = -EINVAL;
+			goto err_cur;
+		}
+	}
+
+	/*
+	 * Check that there haven't been another update to the seqnr since we
+	 * began
+	 */
+	if ((new->seqnr - 1) != be32_to_cpu(cur->seqnr)) {
+		pr_err("nvm: seq is not sequential\n");
+		ret = -EINVAL;
+		goto err_cur;
+	}
+
+	/*
+	 * When all pages in a block has been written, a new block is selected
+	 * and writing is performed on the new block.
+	 */
+	if (s.ppas[scan_ppa_idx(0, s.act_blk[0])].g.pg ==
+						dev->lps_per_blk - 1) {
+		ret = nvm_prepare_new_sysblks(dev, &s);
+		if (ret)
+			goto err_cur;
+	}
+
+	ret = nvm_write_and_verify(dev, new, &s);
+err_cur:
+	kfree(cur);
+err_sysblk:
+	mutex_unlock(&dev->mlock);
+
+	return ret;
+}
+
+int nvm_init_sysblock(struct nvm_dev *dev, struct nvm_sb_info *info)
+{
+	struct ppa_addr sysblk_ppas[MAX_SYSBLKS];
+	struct sysblk_scan s;
+	int ret;
+
+	/*
+	 * 1. select master blocks and select first available blks
+	 * 2. get bad block list
+	 * 3. mark MAX_SYSBLKS block as host-based device allocated.
+	 * 4. write and verify data to block
+	 */
+
+	if (!dev->ops->get_bb_tbl || !dev->ops->set_bb_tbl)
+		return -EINVAL;
+
+	if (!(dev->mccap & NVM_ID_CAP_SLC) || !dev->lps_per_blk) {
+		pr_err("nvm: memory does not support SLC access\n");
+		return -EINVAL;
+	}
+
+	/* Index all sysblocks and mark them as host-driven */
+	nvm_setup_sysblk_scan(dev, &s, sysblk_ppas);
+
+	mutex_lock(&dev->mlock);
+	ret = nvm_get_all_sysblks(dev, &s, sysblk_ppas, sysblk_get_free_blks);
+	if (ret)
+		goto err_mark;
+
+	ret = nvm_set_bb_tbl(dev, &s, NVM_BLK_T_HOST);
+	if (ret)
+		goto err_mark;
+
+	/* Write to the first block of each row */
+	ret = nvm_write_and_verify(dev, info, &s);
+err_mark:
+	mutex_unlock(&dev->mlock);
+	return ret;
+}