ide: add support for arbitrary transfer lengths to ide_pio_bytes()

Add support for arbitrary transfer lengths to ide_pio_bytes()
and then inline ide_pio_multi() into ide_pio_datablock().

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 37 insertions, 36 deletions

diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 84532be97c00..8d7e87d04b3b 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -189,7 +189,7 @@ static u8 wait_drive_not_busy(ide_drive_t *drive)
 }
 
 static void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd,
-                          unsigned int write, unsigned int nr_bytes)
+                          unsigned int write, unsigned int len)
 {
         ide_hwif_t *hwif = drive->hwif;
         struct scatterlist *sg = hwif->sg_table;
@@ -202,56 +202,55 @@ static void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd,
         u8 *buf;
 
         cursg = cmd->cursg;
-        if (!cursg) {
-                cursg = sg;
-                cmd->cursg = sg;
-        }
+        if (cursg == NULL)
+                cursg = cmd->cursg = sg;
+
+        while (len) {
+                unsigned nr_bytes = min(len, cursg->length - cmd->cursg_ofs);
 
-        page = sg_page(cursg);
-        offset = cursg->offset + cmd->cursg_ofs;
+                if (nr_bytes > PAGE_SIZE)
+                        nr_bytes = PAGE_SIZE;
 
-        /* get the current page and offset */
-        page = nth_page(page, (offset >> PAGE_SHIFT));
-        offset %= PAGE_SIZE;
+                page = sg_page(cursg);
+                offset = cursg->offset + cmd->cursg_ofs;
+
+                /* get the current page and offset */
+                page = nth_page(page, (offset >> PAGE_SHIFT));
+                offset %= PAGE_SIZE;
 
 #ifdef CONFIG_HIGHMEM
-        local_irq_save(flags);
+                local_irq_save(flags);
 #endif
-        buf = kmap_atomic(page, KM_BIO_SRC_IRQ) + offset;
+                buf = kmap_atomic(page, KM_BIO_SRC_IRQ) + offset;
 
-        cmd->nleft -= nr_bytes;
-        cmd->cursg_ofs += nr_bytes;
+                cmd->nleft -= nr_bytes;
+                cmd->cursg_ofs += nr_bytes;
 
-        if (cmd->cursg_ofs == cursg->length) {
-                cmd->cursg = sg_next(cmd->cursg);
-                cmd->cursg_ofs = 0;
-        }
+                if (cmd->cursg_ofs == cursg->length) {
+                        cursg = cmd->cursg = sg_next(cmd->cursg);
+                        cmd->cursg_ofs = 0;
+                }
 
-        /* do the actual data transfer */
-        if (write)
-                hwif->tp_ops->output_data(drive, cmd, buf, nr_bytes);
-        else
-                hwif->tp_ops->input_data(drive, cmd, buf, nr_bytes);
+                /* do the actual data transfer */
+                if (write)
+                        hwif->tp_ops->output_data(drive, cmd, buf, nr_bytes);
+                else
+                        hwif->tp_ops->input_data(drive, cmd, buf, nr_bytes);
 
-        kunmap_atomic(buf, KM_BIO_SRC_IRQ);
+                kunmap_atomic(buf, KM_BIO_SRC_IRQ);
 #ifdef CONFIG_HIGHMEM
-        local_irq_restore(flags);
+                local_irq_restore(flags);
 #endif
-}
-
-static void ide_pio_multi(ide_drive_t *drive, struct ide_cmd *cmd,
-                          unsigned int write)
-{
-        unsigned int nsect;
 
-        nsect = min_t(unsigned int, cmd->nleft >> 9, drive->mult_count);
-        while (nsect--)
-                ide_pio_bytes(drive, cmd, write, SECTOR_SIZE);
+                len -= nr_bytes;
+        }
 }
 
 static void ide_pio_datablock(ide_drive_t *drive, struct ide_cmd *cmd,
                               unsigned int write)
 {
+        unsigned int nr_bytes;
+
         u8 saved_io_32bit = drive->io_32bit;
 
         if (cmd->tf_flags & IDE_TFLAG_FS)
@@ -263,9 +262,11 @@ static void ide_pio_datablock(ide_drive_t *drive, struct ide_cmd *cmd,
         touch_softlockup_watchdog();
 
         if (cmd->tf_flags & IDE_TFLAG_MULTI_PIO)
-                ide_pio_multi(drive, cmd, write);
+                nr_bytes = min_t(unsigned, cmd->nleft, drive->mult_count << 9);
         else
-                ide_pio_bytes(drive, cmd, write, SECTOR_SIZE);
+                nr_bytes = SECTOR_SIZE;
+
+        ide_pio_bytes(drive, cmd, write, nr_bytes);
 
         drive->io_32bit = saved_io_32bit;
 }