[PATCH] libata: interrupt driven pio for libata-core
- add PIO_ST_FIRST for the state before sending ATAPI CDB or sending
"ATA PIO data out" first data block.
- add ATA_TFLAG_POLLING and ATA_DFLAG_CDB_INTR flags
- remove the ATA_FLAG_NOINTR flag since the interrupt handler is now
aware of the states
- modify ata_pio_sector() and atapi_pio_bytes() to work in the interrupt
context
- modify the ata_host_intr() to handle PIO interrupts
- modify ata_qc_issue_prot() to initialize states
- atapi_packet_task() changed to handle "ATA PIO data out" first data block
- support the pre-ATA4 ATAPI device which raise interrupt when ready to
receive CDB
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index c4fcdc3..cc2d130 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1292,6 +1292,9 @@
ap->cdb_len = (unsigned int) rc;
ap->host->max_cmd_len = (unsigned char) ap->cdb_len;
+ if (ata_id_cdb_intr(dev->id))
+ dev->flags |= ATA_DFLAG_CDB_INTR;
+
/* print device info to dmesg */
printk(KERN_INFO "ata%u: dev %u ATAPI, max %s\n",
ap->id, device,
@@ -2405,7 +2408,6 @@
unsigned long flags;
spin_lock_irqsave(&ap->host_set->lock, flags);
- ap->flags &= ~ATA_FLAG_NOINTR;
ata_irq_on(ap);
ata_qc_complete(qc, drv_stat);
spin_unlock_irqrestore(&ap->host_set->lock, flags);
@@ -2660,6 +2662,7 @@
struct page *page;
unsigned int offset;
unsigned char *buf;
+ unsigned long flags;
if (qc->cursect == (qc->nsect - 1))
ap->hsm_task_state = HSM_ST_LAST;
@@ -2671,7 +2674,8 @@
page = nth_page(page, (offset >> PAGE_SHIFT));
offset %= PAGE_SIZE;
- buf = kmap(page) + offset;
+ local_irq_save(flags);
+ buf = kmap_atomic(page, KM_IRQ0) + offset;
qc->cursect++;
qc->cursg_ofs++;
@@ -2687,7 +2691,8 @@
do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
ata_data_xfer(ap, buf, ATA_SECT_SIZE, do_write);
- kunmap(page);
+ kunmap_atomic(buf - offset, KM_IRQ0);
+ local_irq_restore(flags);
}
/**
@@ -2710,6 +2715,7 @@
struct page *page;
unsigned char *buf;
unsigned int offset, count;
+ unsigned long flags;
if (qc->curbytes + bytes >= qc->nbytes)
ap->hsm_task_state = HSM_ST_LAST;
@@ -2753,7 +2759,8 @@
/* don't cross page boundaries */
count = min(count, (unsigned int)PAGE_SIZE - offset);
- buf = kmap(page) + offset;
+ local_irq_save(flags);
+ buf = kmap_atomic(page, KM_IRQ0) + offset;
bytes -= count;
qc->curbytes += count;
@@ -2769,7 +2776,8 @@
/* do the actual data transfer */
ata_data_xfer(ap, buf, count, do_write);
- kunmap(page);
+ kunmap_atomic(buf - offset, KM_IRQ0);
+ local_irq_restore(flags);
if (bytes)
goto next_sg;
@@ -2808,6 +2816,8 @@
if (do_write != i_write)
goto err_out;
+ VPRINTK("ata%u: xfering %d bytes\n", ap->id, bytes);
+
__atapi_pio_bytes(qc, bytes);
return;
@@ -3054,6 +3064,8 @@
printk(KERN_ERR "ata%u: command 0x%x timeout, stat 0x%x host_stat 0x%x\n",
ap->id, qc->tf.command, drv_stat, host_stat);
+ ap->hsm_task_state = HSM_ST_IDLE;
+
/* complete taskfile transaction */
ata_qc_complete(qc, drv_stat);
break;
@@ -3344,43 +3356,96 @@
{
struct ata_port *ap = qc->ap;
+ /* select the device */
ata_dev_select(ap, qc->dev->devno, 1, 0);
+ /* start the command */
switch (qc->tf.protocol) {
case ATA_PROT_NODATA:
+ if (qc->tf.flags & ATA_TFLAG_POLLING)
+ ata_qc_set_polling(qc);
+
ata_tf_to_host_nolock(ap, &qc->tf);
+ ap->hsm_task_state = HSM_ST_LAST;
+
+ if (qc->tf.flags & ATA_TFLAG_POLLING)
+ queue_work(ata_wq, &ap->pio_task);
+
break;
case ATA_PROT_DMA:
+ assert(!(qc->tf.flags & ATA_TFLAG_POLLING));
+
ap->ops->tf_load(ap, &qc->tf); /* load tf registers */
ap->ops->bmdma_setup(qc); /* set up bmdma */
ap->ops->bmdma_start(qc); /* initiate bmdma */
+ ap->hsm_task_state = HSM_ST_LAST;
break;
- case ATA_PROT_PIO: /* load tf registers, initiate polling pio */
- ata_qc_set_polling(qc);
+ case ATA_PROT_PIO:
+ if (qc->tf.flags & ATA_TFLAG_POLLING)
+ ata_qc_set_polling(qc);
+
ata_tf_to_host_nolock(ap, &qc->tf);
- ap->hsm_task_state = HSM_ST;
- queue_work(ata_wq, &ap->pio_task);
+
+ if (qc->tf.flags & ATA_TFLAG_POLLING) {
+ /* polling PIO */
+ ap->hsm_task_state = HSM_ST;
+ queue_work(ata_wq, &ap->pio_task);
+ } else {
+ /* interrupt driven PIO */
+ if (qc->tf.flags & ATA_TFLAG_WRITE) {
+ /* PIO data out protocol */
+ ap->hsm_task_state = HSM_ST_FIRST;
+ queue_work(ata_wq, &ap->packet_task);
+
+ /* send first data block by polling */
+ } else {
+ /* PIO data in protocol */
+ ap->hsm_task_state = HSM_ST;
+
+ /* interrupt handler takes over from here */
+ }
+ }
+
break;
case ATA_PROT_ATAPI:
- ata_qc_set_polling(qc);
+ if (qc->tf.flags & ATA_TFLAG_POLLING)
+ ata_qc_set_polling(qc);
+
ata_tf_to_host_nolock(ap, &qc->tf);
- queue_work(ata_wq, &ap->packet_task);
+ ap->hsm_task_state = HSM_ST_FIRST;
+
+ /* send cdb by polling if no cdb interrupt */
+ if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
+ (qc->tf.flags & ATA_TFLAG_POLLING))
+ queue_work(ata_wq, &ap->packet_task);
break;
case ATA_PROT_ATAPI_NODATA:
- ap->flags |= ATA_FLAG_NOINTR;
+ if (qc->tf.flags & ATA_TFLAG_POLLING)
+ ata_qc_set_polling(qc);
+
ata_tf_to_host_nolock(ap, &qc->tf);
- queue_work(ata_wq, &ap->packet_task);
+ ap->hsm_task_state = HSM_ST_FIRST;
+
+ /* send cdb by polling if no cdb interrupt */
+ if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
+ (qc->tf.flags & ATA_TFLAG_POLLING))
+ queue_work(ata_wq, &ap->packet_task);
break;
case ATA_PROT_ATAPI_DMA:
- ap->flags |= ATA_FLAG_NOINTR;
+ assert(!(qc->tf.flags & ATA_TFLAG_POLLING));
+
ap->ops->tf_load(ap, &qc->tf); /* load tf registers */
ap->ops->bmdma_setup(qc); /* set up bmdma */
- queue_work(ata_wq, &ap->packet_task);
+ ap->hsm_task_state = HSM_ST_FIRST;
+
+ /* send cdb by polling if no cdb interrupt */
+ if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
+ queue_work(ata_wq, &ap->packet_task);
break;
default:
@@ -3623,6 +3688,42 @@
}
/**
+ * atapi_send_cdb - Write CDB bytes to hardware
+ * @ap: Port to which ATAPI device is attached.
+ * @qc: Taskfile currently active
+ *
+ * When device has indicated its readiness to accept
+ * a CDB, this function is called. Send the CDB.
+ *
+ * LOCKING:
+ * caller.
+ */
+
+static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
+{
+ /* send SCSI cdb */
+ DPRINTK("send cdb\n");
+ assert(ap->cdb_len >= 12);
+
+ ata_data_xfer(ap, qc->cdb, ap->cdb_len, 1);
+ ata_altstatus(ap); /* flush */
+
+ switch (qc->tf.protocol) {
+ case ATA_PROT_ATAPI:
+ ap->hsm_task_state = HSM_ST;
+ break;
+ case ATA_PROT_ATAPI_NODATA:
+ ap->hsm_task_state = HSM_ST_LAST;
+ break;
+ case ATA_PROT_ATAPI_DMA:
+ ap->hsm_task_state = HSM_ST_LAST;
+ /* initiate bmdma */
+ ap->ops->bmdma_start(qc);
+ break;
+ }
+}
+
+/**
* ata_host_intr - Handle host interrupt for given (port, task)
* @ap: Port on which interrupt arrived (possibly...)
* @qc: Taskfile currently active in engine
@@ -3641,47 +3742,142 @@
inline unsigned int ata_host_intr (struct ata_port *ap,
struct ata_queued_cmd *qc)
{
- u8 status, host_stat;
+ u8 status, host_stat = 0;
- switch (qc->tf.protocol) {
+ VPRINTK("ata%u: protocol %d task_state %d\n",
+ ap->id, qc->tf.protocol, ap->hsm_task_state);
- case ATA_PROT_DMA:
- case ATA_PROT_ATAPI_DMA:
- case ATA_PROT_ATAPI:
- /* check status of DMA engine */
- host_stat = ap->ops->bmdma_status(ap);
- VPRINTK("ata%u: host_stat 0x%X\n", ap->id, host_stat);
-
- /* if it's not our irq... */
- if (!(host_stat & ATA_DMA_INTR))
+ /* Check whether we are expecting interrupt in this state */
+ switch (ap->hsm_task_state) {
+ case HSM_ST_FIRST:
+ /* Check the ATA_DFLAG_CDB_INTR flag is enough here.
+ * The flag was turned on only for atapi devices.
+ * No need to check is_atapi_taskfile(&qc->tf) again.
+ */
+ if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
goto idle_irq;
+ break;
+ case HSM_ST_LAST:
+ if (qc->tf.protocol == ATA_PROT_DMA ||
+ qc->tf.protocol == ATA_PROT_ATAPI_DMA) {
+ /* check status of DMA engine */
+ host_stat = ap->ops->bmdma_status(ap);
+ VPRINTK("ata%u: host_stat 0x%X\n", ap->id, host_stat);
- /* before we do anything else, clear DMA-Start bit */
- ap->ops->bmdma_stop(qc);
+ /* if it's not our irq... */
+ if (!(host_stat & ATA_DMA_INTR))
+ goto idle_irq;
- /* fall through */
+ /* before we do anything else, clear DMA-Start bit */
+ ap->ops->bmdma_stop(qc);
+ }
+ break;
+ case HSM_ST:
+ break;
+ default:
+ goto idle_irq;
+ }
- case ATA_PROT_ATAPI_NODATA:
- case ATA_PROT_NODATA:
- /* check altstatus */
- status = ata_altstatus(ap);
- if (status & ATA_BUSY)
- goto idle_irq;
+ /* check altstatus */
+ status = ata_altstatus(ap);
+ if (status & ATA_BUSY)
+ goto idle_irq;
- /* check main status, clearing INTRQ */
- status = ata_chk_status(ap);
- if (unlikely(status & ATA_BUSY))
- goto idle_irq;
- DPRINTK("ata%u: protocol %d (dev_stat 0x%X)\n",
- ap->id, qc->tf.protocol, status);
+ /* check main status, clearing INTRQ */
+ status = ata_chk_status(ap);
+ if (unlikely(status & ATA_BUSY))
+ goto idle_irq;
- /* ack bmdma irq events */
- ap->ops->irq_clear(ap);
+ DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
+ ap->id, qc->tf.protocol, ap->hsm_task_state, status);
+
+ /* ack bmdma irq events */
+ ap->ops->irq_clear(ap);
+
+ /* check error */
+ if (unlikely((status & ATA_ERR) || (host_stat & ATA_DMA_ERR)))
+ ap->hsm_task_state = HSM_ST_ERR;
+
+fsm_start:
+ switch (ap->hsm_task_state) {
+ case HSM_ST_FIRST:
+ /* Some pre-ATAPI-4 devices assert INTRQ
+ * at this state when ready to receive CDB.
+ */
+
+ /* check device status */
+ if (unlikely((status & (ATA_BUSY | ATA_DRQ)) != ATA_DRQ)) {
+ /* Wrong status. Let EH handle this */
+ ap->hsm_task_state = HSM_ST_ERR;
+ goto fsm_start;
+ }
+
+ atapi_send_cdb(ap, qc);
+
+ break;
+
+ case HSM_ST:
+ /* complete command or read/write the data register */
+ if (qc->tf.protocol == ATA_PROT_ATAPI) {
+ /* ATAPI PIO protocol */
+ if ((status & ATA_DRQ) == 0) {
+ /* no more data to transfer */
+ ap->hsm_task_state = HSM_ST_LAST;
+ goto fsm_start;
+ }
+
+ atapi_pio_bytes(qc);
+
+ if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
+ /* bad ireason reported by device */
+ goto fsm_start;
+
+ } else {
+ /* ATA PIO protocol */
+ if (unlikely((status & ATA_DRQ) == 0)) {
+ /* handle BSY=0, DRQ=0 as error */
+ ap->hsm_task_state = HSM_ST_ERR;
+ goto fsm_start;
+ }
+
+ ata_pio_sector(qc);
+
+ if (ap->hsm_task_state == HSM_ST_LAST &&
+ (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
+ /* all data read */
+ ata_altstatus(ap);
+ status = ata_chk_status(ap);
+ goto fsm_start;
+ }
+ }
+
+ ata_altstatus(ap); /* flush */
+ break;
+
+ case HSM_ST_LAST:
+ if (unlikely(status & ATA_DRQ)) {
+ /* handle DRQ=1 as error */
+ ap->hsm_task_state = HSM_ST_ERR;
+ goto fsm_start;
+ }
+
+ /* no more data to transfer */
+ DPRINTK("ata%u: command complete, drv_stat 0x%x\n",
+ ap->id, status);
+
+ ap->hsm_task_state = HSM_ST_IDLE;
/* complete taskfile transaction */
ata_qc_complete(qc, status);
break;
+ case HSM_ST_ERR:
+ printk(KERN_ERR "ata%u: command error, drv_stat 0x%x host_stat 0x%x\n",
+ ap->id, status, host_stat);
+
+ ap->hsm_task_state = HSM_ST_IDLE;
+ ata_qc_complete(qc, status | ATA_ERR);
+ break;
default:
goto idle_irq;
}
@@ -3733,11 +3929,11 @@
ap = host_set->ports[i];
if (ap &&
- !(ap->flags & (ATA_FLAG_PORT_DISABLED | ATA_FLAG_NOINTR))) {
+ !(ap->flags & ATA_FLAG_PORT_DISABLED)) {
struct ata_queued_cmd *qc;
qc = ata_qc_from_tag(ap, ap->active_tag);
- if (qc && (!(qc->tf.ctl & ATA_NIEN)) &&
+ if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
(qc->flags & ATA_QCFLAG_ACTIVE))
handled |= ata_host_intr(ap, qc);
}
@@ -3767,6 +3963,7 @@
struct ata_port *ap = _data;
struct ata_queued_cmd *qc;
u8 status;
+ unsigned long flags;
qc = ata_qc_from_tag(ap, ap->active_tag);
assert(qc != NULL);
@@ -3782,38 +3979,40 @@
if ((status & (ATA_BUSY | ATA_DRQ)) != ATA_DRQ)
goto err_out;
- /* send SCSI cdb */
- DPRINTK("send cdb\n");
- assert(ap->cdb_len >= 12);
+ /* Send the CDB (atapi) or the first data block (ata pio out).
+ * During the state transition, interrupt handler shouldn't
+ * be invoked before the data transfer is complete and
+ * hsm_task_state is changed. Hence, the following locking.
+ */
+ spin_lock_irqsave(&ap->host_set->lock, flags);
- if (qc->tf.protocol == ATA_PROT_ATAPI_DMA ||
- qc->tf.protocol == ATA_PROT_ATAPI_NODATA) {
- unsigned long flags;
+ if (is_atapi_taskfile(&qc->tf)) {
+ /* send CDB */
+ atapi_send_cdb(ap, qc);
- /* Once we're done issuing command and kicking bmdma,
- * irq handler takes over. To not lose irq, we need
- * to clear NOINTR flag before sending cdb, but
- * interrupt handler shouldn't be invoked before we're
- * finished. Hence, the following locking.
- */
- spin_lock_irqsave(&ap->host_set->lock, flags);
- ap->flags &= ~ATA_FLAG_NOINTR;
- ata_data_xfer(ap, qc->cdb, ap->cdb_len, 1);
- if (qc->tf.protocol == ATA_PROT_ATAPI_DMA)
- ap->ops->bmdma_start(qc); /* initiate bmdma */
- spin_unlock_irqrestore(&ap->host_set->lock, flags);
+ if (qc->tf.flags & ATA_TFLAG_POLLING)
+ queue_work(ata_wq, &ap->pio_task);
} else {
- ata_data_xfer(ap, qc->cdb, ap->cdb_len, 1);
+ /* PIO data out protocol.
+ * send first data block.
+ */
- /* PIO commands are handled by polling */
+ /* ata_pio_sector() might change the state to HSM_ST_LAST.
+ * so, the state is changed here before ata_pio_sector().
+ */
ap->hsm_task_state = HSM_ST;
- queue_work(ata_wq, &ap->pio_task);
+ ata_pio_sector(qc);
+ ata_altstatus(ap); /* flush */
+
+ /* interrupt handler takes over from here */
}
+ spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
return;
err_out:
- ata_poll_qc_complete(qc, ATA_ERR);
+ ata_pio_error(ap);
}