ide-floppy: use scatterlists for pio transfers

Use hwif->sg_table for pio transfers instead of fumbling
with block layer internals in the driver. Also, make debug
statements more informative in .._do_request() while at it.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
[bart: fixup pc->b_count in idefloppy_blockpc_cmd()]
[bart: add missing include (noticed by Stephen Rothwell)]
[bart: map hwif->sg_{table,nents} on pc->{sg,sg_cnt} (multi-IRQs-per-sg fix)]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index 84c333e443491c3446ac4995e660469b19c09d6c..06db5edf9ceec7b7656a5057ccafbe142f5796f5 100644 (file)
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -36,6 +36,7 @@
 #include <linux/hdreg.h>
 #include <linux/bitops.h>
 #include <linux/mutex.h>
+#include <linux/scatterlist.h>
 
 #include <scsi/scsi_ioctl.h>
 
@@ -226,29 +227,36 @@ 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;
-       struct request *rq = pc->rq;
-       struct req_iterator iter;
-       struct bio_vec *bvec;
-       unsigned long flags;
+       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;
-       char *data;
-
-       rq_for_each_segment(bvec, rq, iter) {
-               if (!bcount)
-                       break;
-
-               count = min(bvec->bv_len, bcount);
-
-               data = bvec_kmap_irq(bvec, &flags);
-               if (direction)
-                       hwif->tp_ops->output_data(drive, NULL, data, count);
-               else
-                       hwif->tp_ops->input_data(drive, NULL, data, count);
-               bvec_kunmap_irq(data, &flags);
 
+       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);
@@ -571,7 +579,7 @@ static void idefloppy_create_rw_cmd(idefloppy_floppy_t *floppy,
        memcpy(rq->cmd, pc->c, 12);
 
        pc->rq = rq;
-       pc->b_count = cmd == READ ? 0 : rq->bio->bi_size;
+       pc->b_count = 0;
        if (rq->cmd_flags & REQ_RW)
                pc->flags |= PC_FLAG_WRITING;
        pc->buf = NULL;
@@ -585,7 +593,7 @@ static void idefloppy_blockpc_cmd(idefloppy_floppy_t *floppy,
        idefloppy_init_pc(pc);
        memcpy(pc->c, rq->cmd, sizeof(pc->c));
        pc->rq = rq;
-       pc->b_count = rq->data_len;
+       pc->b_count = 0;
        if (rq->data_len && rq_data_dir(rq) == WRITE)
                pc->flags |= PC_FLAG_WRITING;
        pc->buf = rq->data;
@@ -602,15 +610,17 @@ static ide_startstop_t idefloppy_do_request(ide_drive_t *drive,
                struct request *rq, sector_t block_s)
 {
        idefloppy_floppy_t *floppy = drive->driver_data;
+       ide_hwif_t *hwif = drive->hwif;
        struct ide_atapi_pc *pc;
        unsigned long block = (unsigned long)block_s;
 
-       debug_log("dev: %s, cmd_type: %x, errors: %d\n",
-                       rq->rq_disk ? rq->rq_disk->disk_name : "?",
-                       rq->cmd_type, rq->errors);
-       debug_log("sector: %ld, nr_sectors: %ld, "
-                       "current_nr_sectors: %d\n", (long)rq->sector,
-                       rq->nr_sectors, rq->current_nr_sectors);
+       debug_log("%s: dev: %s, cmd: 0x%x, cmd_type: %x, errors: %d\n",
+                 __func__, rq->rq_disk ? rq->rq_disk->disk_name : "?",
+                 rq->cmd[0], rq->cmd_type, rq->errors);
+
+       debug_log("%s: sector: %ld, nr_sectors: %ld, current_nr_sectors: %d\n",
+                 __func__, (long)rq->sector, rq->nr_sectors,
+                 rq->current_nr_sectors);
 
        if (rq->errors >= ERROR_MAX) {
                if (floppy->failed_pc)
@@ -643,6 +653,12 @@ static ide_startstop_t idefloppy_do_request(ide_drive_t *drive,
                return ide_stopped;
        }
 
+       ide_init_sg_cmd(drive, rq);
+       ide_map_sg(drive, rq);
+
+       pc->sg = hwif->sg_table;
+       pc->sg_cnt = hwif->sg_nents;
+
        pc->rq = rq;
 
        return idefloppy_issue_pc(drive, pc);