Write-while-program support v2

This is from Adrian hunter and modified for write_ops operation.

It's similar with read-while-program method.
but it's write side performance improvement.

Here's *updated* brief performance results.
Note: Measured from OMAP3 with async OneNAND mode. (not sync mode)

=================================================================
speedtest: dev = 3
speedtest: Size=16777216 EB size=131072 Write size=2048 EB count=128

                Pages per EB=64  Page size=2048

speedtest: scanning for bad blocks
speedtest: scanned 0
speedtest: scanned 128, found 0 bad
speedtest: erasing
speedtest: erased 0
speedtest: erased 128
speedtest: Testing eraseblock write speed
eraseblock write speed is 2592 KiB/s
speedtest: Testing eraseblock read speed
eraseblock read speed is 16786 KiB/s
speedtest: Testing page write speed
page write speed is 2966 KiB/s
speedtest: Testing page read speed
page read speed is 13277 KiB/s
speedtest: Testing 2 page write speed
2 page write speed is 3182 KiB/s
speedtest: Testing 2 page read speed
2 page read speed is 14773 KiB/s
speedtest: Testing erase speed
erase speed is 192752 KiB/s
speedtest: speedtest finished
=================================================================

Also it's passed all nand-tests.

index aaf3504..5a27adb 100644
@@ -1455,7 +1455,8 @@ static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
 				struct mtd_oob_ops *ops)
 {
 	struct onenand_chip *this = mtd->priv;
-	int written = 0, column, thislen, subpage;
+	int written = 0, column, thislen = 0, subpage = 0;
+	int prev = 0, prevlen = 0, prev_subpage = 0, first = 1;
 	int oobwritten = 0, oobcolumn, thisooblen, oobsize;
 	size_t len = ops->len;
 	size_t ooblen = ops->ooblen;

@@ -1482,6 +1483,10 @@ static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
                 return -EINVAL;
         }
 
+	/* Check zero length */
+	if (!len)
+		return 0;
+
 	if (ops->mode == MTD_OOB_AUTO)
 		oobsize = this->ecclayout->oobavail;
 	else

@@ -1492,79 +1497,125 @@ static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
 	column = to & (mtd->writesize - 1);
 
 	/* Loop until all data write */
-	while (written < len) {
-		u_char *wbuf = (u_char *) buf;
+	while (1) {
+		if (written < len) {
+			u_char *wbuf = (u_char *) buf;
 
-		thislen = min_t(int, mtd->writesize - column, len - written);
-		thisooblen = min_t(int, oobsize - oobcolumn, ooblen - oobwritten);
+			thislen = min_t(int, mtd->writesize - column, len - written);
+			thisooblen = min_t(int, oobsize - oobcolumn, ooblen - oobwritten);
 
-		cond_resched();
+			cond_resched();
 
-		this->command(mtd, ONENAND_CMD_BUFFERRAM, to, thislen);
+			this->command(mtd, ONENAND_CMD_BUFFERRAM, to, thislen);
 
-		/* Partial page write */
-		subpage = thislen < mtd->writesize;
-		if (subpage) {
-			memset(this->page_buf, 0xff, mtd->writesize);
-			memcpy(this->page_buf + column, buf, thislen);
-			wbuf = this->page_buf;
-		}
+			/* Partial page write */
+			subpage = thislen < mtd->writesize;
+			if (subpage) {
+				memset(this->page_buf, 0xff, mtd->writesize);
+				memcpy(this->page_buf + column, buf, thislen);
+				wbuf = this->page_buf;
+			}
 
-		this->write_bufferram(mtd, ONENAND_DATARAM, wbuf, 0, mtd->writesize);
+			this->write_bufferram(mtd, ONENAND_DATARAM, wbuf, 0, mtd->writesize);
 
-		if (oob) {
-			oobbuf = this->oob_buf;
+			if (oob) {
+				oobbuf = this->oob_buf;
 
-			/* We send data to spare ram with oobsize
-			 * to prevent byte access */
-			memset(oobbuf, 0xff, mtd->oobsize);
-			if (ops->mode == MTD_OOB_AUTO)
-				onenand_fill_auto_oob(mtd, oobbuf, oob, oobcolumn, thisooblen);
-			else
-				memcpy(oobbuf + oobcolumn, oob, thisooblen);
+				/* We send data to spare ram with oobsize
+				 * to prevent byte access */
+				memset(oobbuf, 0xff, mtd->oobsize);
+				if (ops->mode == MTD_OOB_AUTO)
+					onenand_fill_auto_oob(mtd, oobbuf, oob, oobcolumn, thisooblen);
+				else
+					memcpy(oobbuf + oobcolumn, oob, thisooblen);
 
-			oobwritten += thisooblen;
-			oob += thisooblen;
-			oobcolumn = 0;
+				oobwritten += thisooblen;
+				oob += thisooblen;
+				oobcolumn = 0;
+			} else
+				oobbuf = (u_char *) ffchars;
+
+			this->write_bufferram(mtd, ONENAND_SPARERAM, oobbuf, 0, mtd->oobsize);
 		} else
-			oobbuf = (u_char *) ffchars;
+			ONENAND_SET_NEXT_BUFFERRAM(this);
 
-		this->write_bufferram(mtd, ONENAND_SPARERAM, oobbuf, 0, mtd->oobsize);
+		/*
+		 * 2 PLANE, MLC, and Flex-OneNAND doesn't support
+		 * write-while-programe feature.
+		 */
+		if (!ONENAND_IS_2PLANE(this) && !first) {
+			ONENAND_SET_PREV_BUFFERRAM(this);
 
-		this->command(mtd, ONENAND_CMD_PROG, to, mtd->writesize);
+			ret = this->wait(mtd, FL_WRITING);
 
-		ret = this->wait(mtd, FL_WRITING);
+			/* In partial page write we don't update bufferram */
+			onenand_update_bufferram(mtd, prev, !ret && !prev_subpage);
+			if (ret) {
+				written -= prevlen;
+				printk(KERN_ERR "onenand_write_ops_nolock: write filaed %d\n", ret);
+				break;
+			}
 
-		/* In partial page write we don't update bufferram */
-		onenand_update_bufferram(mtd, to, !ret && !subpage);
-		if (ONENAND_IS_2PLANE(this)) {
-			ONENAND_SET_BUFFERRAM1(this);
-			onenand_update_bufferram(mtd, to + this->writesize, !ret && !subpage);
-		}
+			if (written == len) {
+				/* Only check verify write turn on */
+				ret = onenand_verify(mtd, buf - len, to - len, len);
+				if (ret) {
+					printk(KERN_ERR "onenand_write_ops_nolock: verify failed %d\n", ret);
+					break;
+				}
+			}
 
-		if (ret) {
-			printk(KERN_ERR "onenand_write_ops_nolock: write filaed %d\n", ret);
-			break;
-		}
+			if (written == len)
+				break;
 
-		/* Only check verify write turn on */
-		ret = onenand_verify(mtd, buf, to, thislen);
-		if (ret) {
-			printk(KERN_ERR "onenand_write_ops_nolock: verify failed %d\n", ret);
-			break;
+			ONENAND_SET_NEXT_BUFFERRAM(this);
 		}
 
-		written += thislen;
+		this->command(mtd, ONENAND_CMD_PROG, to, mtd->writesize);
 
-		if (written == len)
-			break;
+		/*
+		 * 2 PLANE, MLC, and Flex-OneNAND wait here
+		 */
+		if (ONENAND_IS_2PLANE(this)) {
+			ret = this->wait(mtd, FL_WRITING);
+
+			/* In partial page write we don't update bufferram */
+			onenand_update_bufferram(mtd, to, !ret && !subpage);
+			if (ret) {
+				printk(KERN_ERR "onenand_write_ops_nolock: write filaed %d\n", ret);
+				break;
+			}
+
+			/* Only check verify write turn on */
+			ret = onenand_verify(mtd, buf, to, thislen);
+			if (ret) {
+				printk(KERN_ERR "onenand_write_ops_nolock: verify failed %d\n", ret);
+				break;
+			}
+
+			written += thislen;
+
+			if (written == len)
+				break;
+
+		} else
+			written += thislen;
 
 		column = 0;
+		prev_subpage = subpage;
+		prev = to;
+		prevlen = thislen;
 		to += thislen;
 		buf += thislen;
+		first = 0;
 	}
 
+	/* In error case, clear all bufferrams */
+	if (written != len)
+		onenand_invalidate_bufferram(mtd, to - written, len);
+
 	ops->retlen = written;
+	ops->oobretlen = oobwritten;
 
 	return ret;
 }

From: Kyungmin Park <[email protected]>
Date: Mon, 17 Nov 2008 17:54:28 +0900

It's similar with read-while-program method.
but it's write side performance improvement.

Here's brief performance results.
Note: Measured from OMAP3 with async OneNAND mode. (not sync mode)

=================================================================
speedtest: dev = 3
speedtest: Size=16777216 EB size=131072 Write size=2048 EB count=128

               Pages per EB=64  Page size=2048

speedtest: scanning for bad blocks
speedtest: scanned 0
speedtest: scanned 128, found 0 bad
speedtest: erasing
speedtest: erased 0
speedtest: erased 128
speedtest: Testing eraseblock write speed
eraseblock write speed is 2592 KiB/s
speedtest: Testing eraseblock read speed
eraseblock read speed is 16786 KiB/s
speedtest: Testing page write speed
page write speed is 2966 KiB/s
speedtest: Testing page read speed
page read speed is 13277 KiB/s
speedtest: Testing 2 page write speed
2 page write speed is 3182 KiB/s
speedtest: Testing 2 page read speed
2 page read speed is 14773 KiB/s
speedtest: Testing erase speed
erase speed is 192752 KiB/s
speedtest: speedtest finished
=================================================================

Also it's passed all nand-tests.

---

Hi

I have made a couple of tiny changes and tested this. I get a 10% - 25% improvement in write speed when writing more than 1 page.

Regards
Adrian

drivers/mtd/onenand/onenand_base.c | 145 ++++++++++++++++++++++++------------

1 files changed, 96 insertions(+), 49 deletions(-)

index 926cf3a..b369459 100644
@@ -1455,7 +1455,8 @@ static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,

struct mtd_oob_ops *ops)

{
	struct onenand_chip *this = mtd->priv;
-	int written = 0, column, thislen, subpage;
+	int written = 0, column, thislen = 0, subpage = 0;
+	int prev = 0, prevlen = 0, prev_subpage = 0, first = 1;
	int oobwritten = 0, oobcolumn, thisooblen, oobsize;
	size_t len = ops->len;
	size_t ooblen = ops->ooblen;
@@ -1482,6 +1483,10 @@ static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
                return -EINVAL;
        }

+ /* Check zero length */
+ if (!len)
+ return 0;
+

	if (ops->mode == MTD_OOB_AUTO)
		oobsize = this->ecclayout->oobavail;
	else
@@ -1492,79 +1497,121 @@ static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
	column = to & (mtd->writesize - 1);

	/* Loop until all data write */

- while (written < len) {
- u_char *wbuf = (u_char *) buf;
+ while (1) {
+ if (written < len) {
+ u_char *wbuf = (u_char *) buf;

- thislen = min_t(int, mtd->writesize - column, len - written);
- thisooblen = min_t(int, oobsize - oobcolumn, ooblen - oobwritten);
+ thislen = min_t(int, mtd->writesize - column, len - written);
+ thisooblen = min_t(int, oobsize - oobcolumn, ooblen - oobwritten);

- cond_resched();
+ cond_resched();

- this->command(mtd, ONENAND_CMD_BUFFERRAM, to, thislen);
+ this->command(mtd, ONENAND_CMD_BUFFERRAM, to, thislen);

- /* Partial page write */
- subpage = thislen < mtd->writesize;
- if (subpage) {
- memset(this->page_buf, 0xff, mtd->writesize);
- memcpy(this->page_buf + column, buf, thislen);
- wbuf = this->page_buf;
- }
+ /* Partial page write */
+ subpage = thislen < mtd->writesize;
+ if (subpage) {
+ memset(this->page_buf, 0xff, mtd->writesize);
+ memcpy(this->page_buf + column, buf, thislen);
+ wbuf = this->page_buf;
+ }

- this->write_bufferram(mtd, ONENAND_DATARAM, wbuf, 0, mtd->writesize);
+ this->write_bufferram(mtd, ONENAND_DATARAM, wbuf, 0, mtd->writesize);

- if (oob) {
- oobbuf = this->oob_buf;
+ if (oob) {
+ oobbuf = this->oob_buf;

- /* We send data to spare ram with oobsize
- * to prevent byte access */
- memset(oobbuf, 0xff, mtd->oobsize);
- if (ops->mode == MTD_OOB_AUTO)
- onenand_fill_auto_oob(mtd, oobbuf, oob, oobcolumn, thisooblen);
- else
- memcpy(oobbuf + oobcolumn, oob, thisooblen);
+ /* We send data to spare ram with oobsize
+ * to prevent byte access */
+ memset(oobbuf, 0xff, mtd->oobsize);
+ if (ops->mode == MTD_OOB_AUTO)
+ onenand_fill_auto_oob(mtd, oobbuf, oob, oobcolumn, thisooblen);
+ else
+ memcpy(oobbuf + oobcolumn, oob, thisooblen);

- oobwritten += thisooblen;
- oob += thisooblen;
- oobcolumn = 0;
+ oobwritten += thisooblen;
+ oob += thisooblen;
+ oobcolumn = 0;
+ } else
+ oobbuf = (u_char *) ffchars;
+

+			this->write_bufferram(mtd, ONENAND_SPARERAM, oobbuf, 0, mtd->oobsize);
		} else

- oobbuf = (u_char *) ffchars;
+ ONENAND_SET_NEXT_BUFFERRAM(this);

- this->write_bufferram(mtd, ONENAND_SPARERAM, oobbuf, 0, mtd->oobsize);
+ /*
+ * 2 PLANE, MLC, and Flex-OneNAND doesn't support
+ * write-while-programe feature.
+ */
+ if (!ONENAND_IS_2PLANE(this) && !first) {
+ ONENAND_SET_PREV_BUFFERRAM(this);

- this->command(mtd, ONENAND_CMD_PROG, to, mtd->writesize);
+ ret = this->wait(mtd, FL_WRITING);

- ret = this->wait(mtd, FL_WRITING);
+ /* In partial page write we don't update bufferram */
+ onenand_update_bufferram(mtd, prev, !ret && !prev_subpage);
+ if (ret) {
+ written -= prevlen;
+ printk(KERN_ERR "onenand_write_ops_nolock: write filaed %d\n", ret);
+ break;
+ }

- /* In partial page write we don't update bufferram */
- onenand_update_bufferram(mtd, to, !ret && !subpage);
- if (ONENAND_IS_2PLANE(this)) {
- ONENAND_SET_BUFFERRAM1(this);
- onenand_update_bufferram(mtd, to + this->writesize, !ret && !subpage);
- }
+ if (written == len) {
+ /* Only check verify write turn on */
+ ret = onenand_verify(mtd, buf - len, to - len, len);
+ if (ret)
+ printk(KERN_ERR "onenand_write_ops_nolock: verify failed %d\n", ret);
+ break;
+ }

- if (ret) {
- printk(KERN_ERR "onenand_write_ops_nolock: write filaed %d\n", ret);
- break;

+			ONENAND_SET_NEXT_BUFFERRAM(this);
		}

- /* Only check verify write turn on */
- ret = onenand_verify(mtd, buf, to, thislen);
- if (ret) {
- printk(KERN_ERR "onenand_write_ops_nolock: verify failed %d\n", ret);
- break;
- }
+ this->command(mtd, ONENAND_CMD_PROG, to, mtd->writesize);

- written += thislen;
+ /*
+ * 2 PLANE, MLC, and Flex-OneNAND wait here
+ */
+ if (ONENAND_IS_2PLANE(this)) {
+ ret = this->wait(mtd, FL_WRITING);

- if (written == len)
- break;
+ /* In partial page write we don't update bufferram */
+ onenand_update_bufferram(mtd, to, !ret && !subpage);
+ if (ret) {
+ printk(KERN_ERR "onenand_write_ops_nolock: write filaed %d\n", ret);
+ break;
+ }
+
+ /* Only check verify write turn on */
+ ret = onenand_verify(mtd, buf, to, thislen);
+ if (ret) {
+ printk(KERN_ERR "onenand_write_ops_nolock: verify failed %d\n", ret);
+ break;
+ }
+
+ written += thislen;
+
+ if (written == len)
+ break;
+
+ } else
+ written += thislen;

		column = 0;
+		prev_subpage = subpage;
+		prev = to;
+		prevlen = thislen;
		to += thislen;
		buf += thislen;
+		first = 0;
	}

+ /* In error case, clear all bufferrams */
+ if (written != len)
+ onenand_invalidate_bufferram(mtd, 0, -1);
+

	ops->retlen = written;

+ ops->oobretlen = oobwritten;

	return ret;
}

1.5.4.3