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 b6670c6..cb05fe2 100644 (file)
--- 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"
 
 /**
@@ -200,7 +200,6 @@ 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);
@@ -230,10 +229,7 @@ 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();
@@ -284,7 +280,6 @@ 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);
@@ -292,10 +287,7 @@ 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;
@@ -887,7 +879,6 @@ 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");
@@ -907,9 +898,8 @@ 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 605812b..d447466 100644 (file)
--- 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;

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index ecde202..c3d653b 100644 (file)
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -42,7 +42,7 @@
 
 #include <linux/err.h>
 #include <linux/crc32.h>
-#include <asm/div64.h>
+#include <linux/math64.h>
 #include "ubi.h"
 
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
@@ -904,10 +904,8 @@ struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
        dbg_msg("scanning is finished");
 
        /* Calculate mean erase counter */
-       if (si->ec_count) {
-               do_div(si->ec_sum, si->ec_count);
-               si->mean_ec = si->ec_sum;
-       }
+       if (si->ec_count)
+               si->mean_ec = div_u64(si->ec_sum, si->ec_count);
 
        if (si->is_empty)
                ubi_msg("empty MTD device detected");

diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c
index 8b89cc1..6b4d1ae 100644 (file)
--- a/drivers/mtd/ubi/upd.c
+++ b/drivers/mtd/ubi/upd.c
@@ -40,7 +40,7 @@
 
 #include <linux/err.h>
 #include <linux/uaccess.h>
-#include <asm/div64.h>
+#include <linux/math64.h>
 #include "ubi.h"
 
 /**
@@ -89,7 +89,6 @@ static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
                               long long bytes)
 {
        int err;
-       uint64_t tmp;
        struct ubi_vtbl_record vtbl_rec;
 
        dbg_gen("clear update marker for volume %d", vol->vol_id);
@@ -101,9 +100,9 @@ static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
 
        if (vol->vol_type == UBI_STATIC_VOLUME) {
                vol->corrupted = 0;
-               vol->used_bytes = tmp = bytes;
-               vol->last_eb_bytes = do_div(tmp, vol->usable_leb_size);
-               vol->used_ebs = tmp;
+               vol->used_bytes = bytes;
+               vol->used_ebs = div_u64_rem(bytes, vol->usable_leb_size,
+                                           &vol->last_eb_bytes);
                if (vol->last_eb_bytes)
                        vol->used_ebs += 1;
                else
@@ -131,7 +130,6 @@ int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
                     long long bytes)
 {
        int i, err;
-       uint64_t tmp;
 
        dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes);
        ubi_assert(!vol->updating && !vol->changing_leb);
@@ -161,9 +159,8 @@ int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
        if (!vol->upd_buf)
                return -ENOMEM;
 
-       tmp = bytes;
-       vol->upd_ebs = !!do_div(tmp, vol->usable_leb_size);
-       vol->upd_ebs += tmp;
+       vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1,
+                              vol->usable_leb_size);
        vol->upd_bytes = bytes;
        vol->upd_received = 0;
        return 0;
@@ -282,7 +279,6 @@ static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
                         const void __user *buf, int count)
 {
-       uint64_t tmp;
        int lnum, offs, err = 0, len, to_write = count;
 
        dbg_gen("write %d of %lld bytes, %lld already passed",
@@ -291,10 +287,7 @@ int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
        if (ubi->ro_mode)
                return -EROFS;
 
-       tmp = vol->upd_received;
-       offs = do_div(tmp, vol->usable_leb_size);
-       lnum = tmp;
-
+       lnum = div_u64_rem(vol->upd_received,  vol->usable_leb_size, &offs);
        if (vol->upd_received + count > vol->upd_bytes)
                to_write = count = vol->upd_bytes - vol->upd_received;
 

diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 3531ca9..545f3bc 100644 (file)
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -24,7 +24,7 @@
  */
 
 #include <linux/err.h>
-#include <asm/div64.h>
+#include <linux/math64.h>
 #include "ubi.h"
 
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
@@ -205,7 +205,6 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
        int i, err, vol_id = req->vol_id, do_free = 1;
        struct ubi_volume *vol;
        struct ubi_vtbl_record vtbl_rec;
-       uint64_t bytes;
        dev_t dev;
 
        if (ubi->ro_mode)
@@ -255,10 +254,8 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
 
        /* Calculate how many eraseblocks are requested */
        vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
-       bytes = req->bytes;
-       if (do_div(bytes, vol->usable_leb_size))
-               vol->reserved_pebs = 1;
-       vol->reserved_pebs += bytes;
+       vol->reserved_pebs += div_u64(req->bytes + vol->usable_leb_size - 1,
+                                     vol->usable_leb_size);
 
        /* Reserve physical eraseblocks */
        if (vol->reserved_pebs > ubi->avail_pebs) {
@@ -301,10 +298,10 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
                vol->used_bytes =
                        (long long)vol->used_ebs * vol->usable_leb_size;
        } else {
-               bytes = vol->used_bytes;
-               vol->last_eb_bytes = do_div(bytes, vol->usable_leb_size);
-               vol->used_ebs = bytes;
-               if (vol->last_eb_bytes)
+               vol->used_ebs = div_u64_rem(vol->used_bytes,
+                                           vol->usable_leb_size,
+                                           &vol->last_eb_bytes);
+               if (vol->last_eb_bytes != 0)
                        vol->used_ebs += 1;
                else
                        vol->last_eb_bytes = vol->usable_leb_size;