ide: add ide_io_buffers() helper

* Make ->io_buffers method return number of bytes transferred.

* Use ide_end_request() instead of idefloppy_end_request()
  in ide_floppy_io_buffers() and then move the call out to
  ide_pc_intr().

* Add ide_io_buffers() helper and convert ide-{floppy,scsi}.c
  to use it instead of ide*_io_buffers().

There should be no functional changes caused by this patch.

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

3 files changed, 63 insertions, 51 deletions

diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 61c52fb665ca..3d44b45650f6 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -61,12 +61,62 @@ int ide_check_atapi_device(ide_drive_t *drive, const char *s)
 }
 EXPORT_SYMBOL_GPL(ide_check_atapi_device);
 
+/* PIO data transfer routine using the scatter gather table. */
+int ide_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
+                    unsigned int bcount, int write)
+{
+        ide_hwif_t *hwif = drive->hwif;
+        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
+        xfer_func_t *xf = write ? tp_ops->output_data : tp_ops->input_data;
+        struct scatterlist *sg = pc->sg;
+        char *buf;
+        int count, done = 0;
+
+        while (bcount) {
+                count = min(sg->length - pc->b_count, bcount);
+
+                if (PageHighMem(sg_page(sg))) {
+                        unsigned long flags;
+
+                        local_irq_save(flags);
+                        buf = kmap_atomic(sg_page(sg), KM_IRQ0) + sg->offset;
+                        xf(drive, NULL, buf + pc->b_count, count);
+                        kunmap_atomic(buf - sg->offset, KM_IRQ0);
+                        local_irq_restore(flags);
+                } else {
+                        buf = sg_virt(sg);
+                        xf(drive, NULL, buf + pc->b_count, count);
+                }
+
+                bcount -= count;
+                pc->b_count += count;
+                done += count;
+
+                if (pc->b_count == sg->length) {
+                        if (!--pc->sg_cnt)
+                                break;
+                        pc->sg = sg = sg_next(sg);
+                        pc->b_count = 0;
+                }
+        }
+
+        if (bcount) {
+                printk(KERN_ERR "%s: %d leftover bytes, %s\n", drive->name,
+                        bcount, write ? "padding with zeros"
+                                      : "discarding data");
+                ide_pad_transfer(drive, write, bcount);
+        }
+
+        return done;
+}
+EXPORT_SYMBOL_GPL(ide_io_buffers);
+
 /* TODO: unify the code thus making some arguments go away */
 ide_startstop_t ide_pc_intr(ide_drive_t *drive, struct ide_atapi_pc *pc,
         ide_handler_t *handler, unsigned int timeout, ide_expiry_t *expiry,
         void (*update_buffers)(ide_drive_t *, struct ide_atapi_pc *),
         void (*retry_pc)(ide_drive_t *), void (*dsc_handle)(ide_drive_t *),
-        void (*io_buffers)(ide_drive_t *, struct ide_atapi_pc *, unsigned, int))
+        int (*io_buffers)(ide_drive_t *, struct ide_atapi_pc *, unsigned, int))
 {
         ide_hwif_t *hwif = drive->hwif;
         struct request *rq = hwif->hwgroup->rq;
@@ -219,9 +269,14 @@ cmd_finished:
 
         if ((drive->media == ide_floppy && !scsi && !pc->buf) ||
             (drive->media == ide_tape && !scsi && pc->bh) ||
-            (scsi && pc->sg))
-                io_buffers(drive, pc, bcount, !!(pc->flags & PC_FLAG_WRITING));
-        else
+            (scsi && pc->sg)) {
+                int done = io_buffers(drive, pc, bcount,
+                                  !!(pc->flags & PC_FLAG_WRITING));
+
+                /* FIXME: don't do partial completions */
+                if (drive->media == ide_floppy && !scsi)
+                        ide_end_request(drive, 1, done >> 9);
+        } else
                 xferfunc(drive, NULL, pc->cur_pos, bcount);
 
         /* Update the current position */
diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index a0a8ad3a3038..38dca45ffd11 100644
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -208,51 +208,6 @@ static int idefloppy_end_request(ide_drive_t *drive, int uptodate, int nsecs)
         return 0;
 }
 
-static void ide_floppy_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
-                                  unsigned int bcount, int direction)
-{
-        ide_hwif_t *hwif = drive->hwif;
-        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
-        xfer_func_t *xf = direction ? tp_ops->output_data : tp_ops->input_data;
-        struct scatterlist *sg = pc->sg;
-        char *buf;
-        int count, done = 0;
-
-        while (bcount) {
-                count = min(sg->length - pc->b_count, bcount);
-                if (PageHighMem(sg_page(sg))) {
-                        unsigned long flags;
-
-                        local_irq_save(flags);
-                        buf = kmap_atomic(sg_page(sg), KM_IRQ0) + sg->offset;
-                        xf(drive, NULL, buf + pc->b_count, count);
-                        kunmap_atomic(buf - sg->offset, KM_IRQ0);
-                        local_irq_restore(flags);
-                } else {
-                        buf = sg_virt(sg);
-                        xf(drive, NULL, buf + pc->b_count, count);
-                }
-                bcount -= count;
-                pc->b_count += count;
-                done += count;
-
-                if (pc->b_count == sg->length) {
-                        if (!--pc->sg_cnt)
-                                break;
-                        pc->sg = sg = sg_next(sg);
-                        pc->b_count = 0;
-                }
-        }
-
-        idefloppy_end_request(drive, 1, done >> 9);
-
-        if (bcount) {
-                printk(KERN_ERR "%s: leftover data in %s, bcount == %d\n",
-                                drive->name, __func__, bcount);
-                ide_pad_transfer(drive, direction, bcount);
-        }
-}
-
 static void idefloppy_update_buffers(ide_drive_t *drive,
                                 struct ide_atapi_pc *pc)
 {
@@ -356,7 +311,7 @@ static ide_startstop_t idefloppy_pc_intr(ide_drive_t *drive)
 
         return ide_pc_intr(drive, floppy->pc, idefloppy_pc_intr,
                            IDEFLOPPY_WAIT_CMD, NULL, idefloppy_update_buffers,
-                           idefloppy_retry_pc, NULL, ide_floppy_io_buffers);
+                           idefloppy_retry_pc, NULL, ide_io_buffers);
 }
 
 /*
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index ba05e03f482b..d4a9c471dd13 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -693,13 +693,15 @@ static void ide_tape_handle_dsc(ide_drive_t *drive)
         idetape_postpone_request(drive);
 }
 
-static void ide_tape_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
+static int ide_tape_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                                 unsigned int bcount, int write)
 {
         if (write)
                 idetape_output_buffers(drive, pc, bcount);
         else
                 idetape_input_buffers(drive, pc, bcount);
+
+        return bcount;
 }
 
 /*