[libata] ATAPI PIO data xfer

Abstract out PIO data xfer to xfer-a-sector and other-stuff pieces,
then add new ATAPI code that uses the common xfer-a-sector code.

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index f981c6f95ca354a995cfb18f55575ae1185a2a2f..7187432cf970a6c65f3595cf4b950ab6c1a1e89d 100644 (file)
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2113,6 +2113,81 @@ static void ata_data_xfer(struct ata_port *ap, unsigned char *buf,
                ata_pio_data_xfer(ap, buf, buflen, do_write);
 }
 
+static void ata_pio_sector(struct ata_queued_cmd *qc)
+{
+       int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
+       struct scatterlist *sg = qc->sg;
+       struct ata_port *ap = qc->ap;
+       struct page *page;
+       unsigned char *buf;
+
+       if (qc->cursect == (qc->nsect - 1))
+               ap->pio_task_state = PIO_ST_LAST;
+
+       page = sg[qc->cursg].page;
+       buf = kmap(page) +
+             sg[qc->cursg].offset + (qc->cursg_ofs * ATA_SECT_SIZE);
+
+       qc->cursect++;
+       qc->cursg_ofs++;
+
+       if ((qc->cursg_ofs * ATA_SECT_SIZE) == sg_dma_len(&sg[qc->cursg])) {
+               qc->cursg++;
+               qc->cursg_ofs = 0;
+       }
+
+       DPRINTK("data %s, drv_stat 0x%X\n",
+               qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read",
+               status);
+
+       /* do the actual data transfer */
+       do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
+       ata_data_xfer(ap, buf, ATA_SECT_SIZE, do_write);
+
+       kunmap(page);
+}
+
+static void atapi_pio_sector(struct ata_queued_cmd *qc)
+{
+       struct ata_port *ap = qc->ap;
+       struct ata_device *dev = qc->dev;
+       unsigned int i, ireason, bc_lo, bc_hi, bytes;
+       int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
+
+       ap->ops->tf_read(ap, &qc->tf);
+       ireason = qc->tf.nsect;
+       bc_lo = qc->tf.lbam;
+       bc_hi = qc->tf.lbah;
+       bytes = (bc_hi << 8) | bc_lo;
+
+       /* shall be cleared to zero, indicating xfer of data */
+       if (ireason & (1 << 0))
+               goto err_out;
+       
+       /* make sure transfer direction matches expected */
+       i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
+       if (do_write != i_write)
+               goto err_out;
+
+       /* make sure byte count is multiple of sector size; not
+       * required by standard (warning! warning!), but IDE driver
+       * does this to simplify things a bit.  We are lazy, and
+       * follow suit.
+       */
+       if (bytes & (ATA_SECT_SIZE - 1))
+               goto err_out;
+
+       for (i = 0; i < (bytes >> 9); i++)
+               ata_pio_sector(qc);
+       
+       return;
+
+err_out:
+       printk(KERN_INFO "ata%u: dev %u: ATAPI check failed\n",
+             ap->id, dev->devno);
+       ap->pio_task_state = PIO_ST_ERR;
+}
+
 /**
  *     ata_pio_sector -
  *     @ap:
@@ -2120,14 +2195,10 @@ static void ata_data_xfer(struct ata_port *ap, unsigned char *buf,
  *     LOCKING:
  */
 
-static void ata_pio_sector(struct ata_port *ap)
+static void ata_pio_block(struct ata_port *ap)
 {
        struct ata_queued_cmd *qc;
-       struct scatterlist *sg;
-       struct page *page;
-       unsigned char *buf;
        u8 status;
-       int do_write;
 
        /*
         * This is purely hueristic.  This is a fast path.
@@ -2157,32 +2228,10 @@ static void ata_pio_sector(struct ata_port *ap)
        qc = ata_qc_from_tag(ap, ap->active_tag);
        assert(qc != NULL);
 
-       sg = qc->sg;
-
-       if (qc->cursect == (qc->nsect - 1))
-               ap->pio_task_state = PIO_ST_LAST;
-
-       page = sg[qc->cursg].page;
-       buf = kmap(page) +
-             sg[qc->cursg].offset + (qc->cursg_ofs * ATA_SECT_SIZE);
-
-       qc->cursect++;
-       qc->cursg_ofs++;
-
-       if ((qc->cursg_ofs * ATA_SECT_SIZE) == sg_dma_len(&sg[qc->cursg])) {
-               qc->cursg++;
-               qc->cursg_ofs = 0;
-       }
-
-       DPRINTK("data %s, drv_stat 0x%X\n",
-               qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read",
-               status);
-
-       /* do the actual data transfer */
-       do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
-       ata_data_xfer(ap, buf, ATA_SECT_SIZE, do_write);
-
-       kunmap(page);
+       if (is_atapi_taskfile(&qc->tf))
+               atapi_pio_sector(qc);
+       else
+               ata_pio_sector(qc);
 }
 
 static void ata_pio_error(struct ata_port *ap)
@@ -2211,7 +2260,7 @@ static void ata_pio_task(void *_data)
 
        switch (ap->pio_task_state) {
        case PIO_ST:
-               ata_pio_sector(ap);
+               ata_pio_block(ap);
                break;
 
        case PIO_ST_LAST: