+ 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);
+
+void ide_init_pc(struct ide_atapi_pc *pc)
+{
+ memset(pc, 0, sizeof(*pc));
+ pc->buf = pc->pc_buf;
+ pc->buf_size = IDE_PC_BUFFER_SIZE;
+}
+EXPORT_SYMBOL_GPL(ide_init_pc);
+
+/*
+ * Generate a new packet command request in front of the request queue, before
+ * the current request, so that it will be processed immediately, on the next
+ * pass through the driver.
+ */
+static void ide_queue_pc_head(ide_drive_t *drive, struct gendisk *disk,
+ struct ide_atapi_pc *pc, struct request *rq)
+{
+ blk_rq_init(NULL, rq);
+ rq->cmd_type = REQ_TYPE_SPECIAL;
+ rq->cmd_flags |= REQ_PREEMPT;
+ rq->buffer = (char *)pc;
+ rq->rq_disk = disk;
+ memcpy(rq->cmd, pc->c, 12);
+ if (drive->media == ide_tape)
+ rq->cmd[13] = REQ_IDETAPE_PC1;
+ ide_do_drive_cmd(drive, rq);
+}
+
+/*
+ * Add a special packet command request to the tail of the request queue,
+ * and wait for it to be serviced.
+ */
+int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
+ struct ide_atapi_pc *pc)
+{
+ struct request *rq;
+ int error;
+
+ rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
+ rq->cmd_type = REQ_TYPE_SPECIAL;
+ rq->buffer = (char *)pc;
+ memcpy(rq->cmd, pc->c, 12);
+ if (drive->media == ide_tape)
+ rq->cmd[13] = REQ_IDETAPE_PC1;
+ error = blk_execute_rq(drive->queue, disk, rq, 0);
+ blk_put_request(rq);
+
+ return error;
+}
+EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
+
+int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
+{
+ struct ide_atapi_pc pc;
+
+ ide_init_pc(&pc);
+ pc.c[0] = TEST_UNIT_READY;
+
+ return ide_queue_pc_tail(drive, disk, &pc);
+}
+EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
+
+int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
+{
+ struct ide_atapi_pc pc;
+
+ ide_init_pc(&pc);
+ pc.c[0] = START_STOP;
+ pc.c[4] = start;
+
+ if (drive->media == ide_tape)
+ pc.flags |= PC_FLAG_WAIT_FOR_DSC;
+
+ return ide_queue_pc_tail(drive, disk, &pc);
+}
+EXPORT_SYMBOL_GPL(ide_do_start_stop);
+
+int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
+{
+ struct ide_atapi_pc pc;
+
+ if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
+ return 0;
+
+ ide_init_pc(&pc);
+ pc.c[0] = ALLOW_MEDIUM_REMOVAL;
+ pc.c[4] = on;
+
+ return ide_queue_pc_tail(drive, disk, &pc);
+}
+EXPORT_SYMBOL_GPL(ide_set_media_lock);
+
+void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
+{
+ ide_init_pc(pc);
+ pc->c[0] = REQUEST_SENSE;
+ if (drive->media == ide_floppy) {
+ pc->c[4] = 255;
+ pc->req_xfer = 18;
+ } else {
+ pc->c[4] = 20;
+ pc->req_xfer = 20;
+ }
+}
+EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
+
+/*
+ * Called when an error was detected during the last packet command.
+ * We queue a request sense packet command in the head of the request list.
+ */
+void ide_retry_pc(ide_drive_t *drive, struct gendisk *disk)
+{
+ struct request *rq = &drive->request_sense_rq;
+ struct ide_atapi_pc *pc = &drive->request_sense_pc;
+
+ (void)ide_read_error(drive);
+ ide_create_request_sense_cmd(drive, pc);
+ if (drive->media == ide_tape)
+ set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
+ ide_queue_pc_head(drive, disk, pc, rq);
+}
+EXPORT_SYMBOL_GPL(ide_retry_pc);
+
+int ide_cd_expiry(ide_drive_t *drive)
+{
+ struct request *rq = drive->hwif->rq;
+ unsigned long wait = 0;
+
+ debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);
+
+ /*
+ * Some commands are *slow* and normally take a long time to complete.
+ * Usually we can use the ATAPI "disconnect" to bypass this, but not all
+ * commands/drives support that. Let ide_timer_expiry keep polling us
+ * for these.
+ */
+ switch (rq->cmd[0]) {
+ case GPCMD_BLANK:
+ case GPCMD_FORMAT_UNIT:
+ case GPCMD_RESERVE_RZONE_TRACK:
+ case GPCMD_CLOSE_TRACK:
+ case GPCMD_FLUSH_CACHE:
+ wait = ATAPI_WAIT_PC;
+ break;
+ default:
+ if (!(rq->cmd_flags & REQ_QUIET))
+ printk(KERN_INFO "cmd 0x%x timed out\n",
+ rq->cmd[0]);
+ wait = 0;
+ break;
+ }
+ return wait;
+}
+EXPORT_SYMBOL_GPL(ide_cd_expiry);
+
+int ide_cd_get_xferlen(struct request *rq)
+{
+ if (blk_fs_request(rq))
+ return 32768;
+ else if (blk_sense_request(rq) || blk_pc_request(rq) ||
+ rq->cmd_type == REQ_TYPE_ATA_PC)
+ return rq->data_len;
+ else
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
+
+/*
+ * This is the usual interrupt handler which will be called during a packet
+ * command. We will transfer some of the data (as requested by the drive)
+ * and will re-point interrupt handler to us.
+ */
+static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
+{
+ struct ide_atapi_pc *pc = drive->pc;
+ ide_hwif_t *hwif = drive->hwif;
+ struct request *rq = hwif->rq;
+ const struct ide_tp_ops *tp_ops = hwif->tp_ops;