From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Fri, 16 Jan 2009 17:08:43 +0000 (+0200)
Subject: UBI: use nicer 64-bit math
X-Git-Tag: v2.6.29-rc4~102^2~3
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3013ee31b6c5fd9a49a81816d6c13e1cdb7a1288;p=pandora-kernel.git

UBI: use nicer 64-bit math

Get rid of 'do_div()' and use more user-friendly primitives from
'linux/math64.h'.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---

diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 0a2d835fec80..f9631eb3fef3 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -41,8 +41,8 @@
 #include <linux/capability.h>
 #include <linux/uaccess.h>
 #include <linux/compat.h>
+#include <linux/math64.h>
 #include <mtd/ubi-user.h>
-#include <asm/div64.h>
 #include "ubi.h"
 
 /**
@@ -195,7 +195,6 @@ static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 	int err, lnum, off, len,  tbuf_size;
 	size_t count_save = count;
 	void *tbuf;
-	uint64_t tmp;
 
 	dbg_gen("read %zd bytes from offset %lld of volume %d",
 		count, *offp, vol->vol_id);
@@ -225,10 +224,7 @@ static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 		return -ENOMEM;
 
 	len = count > tbuf_size ? tbuf_size : count;
-
-	tmp = *offp;
-	off = do_div(tmp, vol->usable_leb_size);
-	lnum = tmp;
+	lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 
 	do {
 		cond_resched();
@@ -279,7 +275,6 @@ static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 	int lnum, off, len, tbuf_size, err = 0;
 	size_t count_save = count;
 	char *tbuf;
-	uint64_t tmp;
 
 	dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 		count, *offp, vol->vol_id);
@@ -287,10 +282,7 @@ static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 	if (vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;
 
-	tmp = *offp;
-	off = do_div(tmp, vol->usable_leb_size);
-	lnum = tmp;
-
+	lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 	if (off & (ubi->min_io_size - 1)) {
 		dbg_err("unaligned position");
 		return -EINVAL;
@@ -882,7 +874,6 @@ static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 	case UBI_IOCRSVOL:
 	{
 		int pebs;
-		uint64_t tmp;
 		struct ubi_rsvol_req req;
 
 		dbg_gen("re-size volume");
@@ -902,9 +893,8 @@ static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 			break;
 		}
 
-		tmp = req.bytes;
-		pebs = !!do_div(tmp, desc->vol->usable_leb_size);
-		pebs += tmp;
+		pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
+			       desc->vol->usable_leb_size);
 
 		mutex_lock(&ubi->volumes_mutex);
 		err = ubi_resize_volume(desc, pebs);
diff --git a/drivers/mtd/ubi/gluebi.c b/drivers/mtd/ubi/gluebi.c
index 6dd4f5e77f82..49cd55ade9c8 100644
--- a/drivers/mtd/ubi/gluebi.c
+++ b/drivers/mtd/ubi/gluebi.c
@@ -28,7 +28,7 @@
  * eraseblock size is equivalent to the logical eraseblock size of the volume.
  */
 
-#include <asm/div64.h>
+#include <linux/math64.h>
 #include "ubi.h"
 
 /**
@@ -109,7 +109,6 @@ static int gluebi_read(struct mtd_info *mtd, loff_t from, size_t len,
 	int err = 0, lnum, offs, total_read;
 	struct ubi_volume *vol;
 	struct ubi_device *ubi;
-	uint64_t tmp = from;
 
 	dbg_gen("read %zd bytes from offset %lld", len, from);
 
@@ -119,9 +118,7 @@ static int gluebi_read(struct mtd_info *mtd, loff_t from, size_t len,
 	vol = container_of(mtd, struct ubi_volume, gluebi_mtd);
 	ubi = vol->ubi;
 
-	offs = do_div(tmp, mtd->erasesize);
-	lnum = tmp;
-
+	lnum = div_u64_rem(from, mtd->erasesize, &offs);
 	total_read = len;
 	while (total_read) {
 		size_t to_read = mtd->erasesize - offs;
@@ -160,7 +157,6 @@ static int gluebi_write(struct mtd_info *mtd, loff_t to, size_t len,
 	int err = 0, lnum, offs, total_written;
 	struct ubi_volume *vol;
 	struct ubi_device *ubi;
-	uint64_t tmp = to;
 
 	dbg_gen("write %zd bytes to offset %lld", len, to);
 
@@ -173,8 +169,7 @@ static int gluebi_write(struct mtd_info *mtd, loff_t to, size_t len,
 	if (ubi->ro_mode)
 		return -EROFS;
 
-	offs = do_div(tmp, mtd->erasesize);
-	lnum = tmp;
+	lnum = div_u64_rem(to, mtd->erasesize, &offs);
 
 	if (len % mtd->writesize || offs % mtd->writesize)
 		return -EINVAL;
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