ide-cd: prepare cdrom_rw_intr() and cdrom_newpc_intr() to be merged

In cdrom_newpc_intr():
* cleanup variables in the 'transfer data' loop

In cdrom_rw_intr():
* rename 'sectors_to_transfer' to 'thislen'
* rename 'this_transfer' to 'blen'
* keep number of bytes (instead of sectors) in 'thislen' and 'blen'
* call 'xferfunc' only once for 'blen'
* cache 'rq->buffer' in 'ptr' variable
* check for 'rq->bio' before setting 'ptr' and 'blen'
* check for 'ptr' instead of 'rq->current_nr_sectors'

There should be no functionality changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 26 insertions, 21 deletions

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 0f17117c5aa0..2a520bd27a37 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1123,8 +1123,8 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
          * transfer data
          */
         while (thislen > 0) {
-                int blen = blen = rq->data_len;
-                char *ptr = rq->data;
+                u8 *ptr = rq->data;
+                int blen = rq->data_len;
 
                 /*
                  * bio backed?
@@ -1207,7 +1207,7 @@ static ide_startstop_t cdrom_rw_intr(ide_drive_t *drive)
         struct cdrom_info *info = drive->driver_data;
         struct request *rq = HWGROUP(drive)->rq;
         xfer_func_t *xferfunc;
-        int stat, ireason, len, sectors_to_transfer, uptodate, nskip;
+        int stat, ireason, len, thislen, uptodate, nskip;
         int dma_error = 0, dma = info->dma, write = rq_data_dir(rq) == WRITE;
         u8 lowcyl = 0, highcyl = 0;
 
@@ -1262,7 +1262,7 @@ static ide_startstop_t cdrom_rw_intr(ide_drive_t *drive)
                 return ide_stopped;
         }
 
-        sectors_to_transfer = len / SECTOR_SIZE;
+        thislen = len;
 
         /* Check that the drive is expecting to do the same thing we are. */
         if (write) {
@@ -1285,12 +1285,12 @@ static ide_startstop_t cdrom_rw_intr(ide_drive_t *drive)
                  */
                 nskip = min_t(int, rq->current_nr_sectors
                                    - bio_cur_sectors(rq->bio),
-                                   sectors_to_transfer);
+                                   thislen >> 9);
 
                 if (nskip > 0) {
                         ide_cd_drain_data(drive, nskip);
                         rq->current_nr_sectors -= nskip;
-                        sectors_to_transfer -= nskip;
+                        thislen -= (nskip << 9);
                 }
 
                 xferfunc = HWIF(drive)->atapi_input_bytes;
@@ -1299,17 +1299,23 @@ static ide_startstop_t cdrom_rw_intr(ide_drive_t *drive)
         /*
          * now loop and read/write the data
          */
-        while (sectors_to_transfer > 0) {
-                int this_transfer;
+        while (thislen > 0) {
+                u8 *ptr = NULL;
+                int blen;
+
+                if (rq->bio) {
+                        ptr = rq->buffer;
+                        blen = rq->current_nr_sectors << 9;
+                }
 
-                if (!rq->current_nr_sectors) {
+                if (!ptr) {
                         if (!write)
                                 /*
                                  * If the buffers are full, cache the rest
                                  * of the data in our internal buffer.
                                  */
                                 cdrom_buffer_sectors(drive, rq->sector,
-                                                     sectors_to_transfer);
+                                                     thislen >> 9);
                         else
                                 printk(KERN_ERR "%s: %s: confused, missing "
                                                 "data\n",
@@ -1320,17 +1326,16 @@ static ide_startstop_t cdrom_rw_intr(ide_drive_t *drive)
                 /*
                  * Figure out how many sectors we can transfer
                  */
-                this_transfer = min_t(int, sectors_to_transfer, rq->current_nr_sectors);
-
-                while (this_transfer > 0) {
-                        xferfunc(drive, rq->buffer, SECTOR_SIZE);
-                        rq->buffer += SECTOR_SIZE;
-                        --rq->nr_sectors;
-                        --rq->current_nr_sectors;
-                        ++rq->sector;
-                        --this_transfer;
-                        --sectors_to_transfer;
-                }
+                if (blen > thislen)
+                        blen = thislen;
+
+                xferfunc(drive, ptr, blen);
+
+                thislen -= blen;
+                rq->buffer += blen;
+                rq->nr_sectors -= (blen >> 9);
+                rq->current_nr_sectors -= (blen >> 9);
+                rq->sector += (blen >> 9);
 
                 /*
                  * current buffer complete, move on