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[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>
This commit is contained in:
Albert Lee 2005-09-27 17:38:03 +08:00 committed by Jeff Garzik
parent 14be71f4c5
commit 312f7da282
3 changed files with 271 additions and 69 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

333
drivers/scsi/libata-core.c
View File

@ -1292,6 +1292,9 @@ retry:
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 @@ void ata_poll_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
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 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
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 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
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 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
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 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
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 @@ next_sg:
/* 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 @@ next_sg:
/* 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 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc)
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 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
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 @@ int ata_qc_issue_prot(struct ata_queued_cmd *qc)
{
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:
@ -3622,6 +3687,42 @@ void ata_bmdma_stop(struct ata_queued_cmd *qc)
ata_altstatus(ap); /* dummy read */
}
/**
* 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...)
@ -3641,47 +3742,142 @@ void ata_bmdma_stop(struct ata_queued_cmd *qc)
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 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
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 @@ static void atapi_packet_task(void *_data)
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 @@ static void atapi_packet_task(void *_data)
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);
}

3
include/linux/ata.h
View File

@ -181,6 +181,7 @@ enum {
ATA_TFLAG_ISADDR = (1 << 1), /* enable r/w to nsect/lba regs */
ATA_TFLAG_DEVICE = (1 << 2), /* enable r/w to device reg */
ATA_TFLAG_WRITE = (1 << 3), /* data dir: host->dev==1 (write) */
ATA_TFLAG_POLLING = (1 << 4), /* set nIEN to 1 and use polling */
};
enum ata_tf_protocols {
@ -250,6 +251,8 @@ struct ata_taskfile {
((u64) (id)[(n) + 1] << 16) | \
((u64) (id)[(n) + 0]) )
#define ata_id_cdb_intr(id) (((id)[0] & 0x60) == 0x20)
static inline int atapi_cdb_len(u16 *dev_id)
{
u16 tmp = dev_id[0] & 0x3;

4
include/linux/libata.h
View File

@ -97,6 +97,7 @@ enum {
ATA_DFLAG_LBA48 = (1 << 0), /* device supports LBA48 */
ATA_DFLAG_PIO = (1 << 1), /* device currently in PIO mode */
ATA_DFLAG_LOCK_SECTORS = (1 << 2), /* don't adjust max_sectors */
ATA_DFLAG_CDB_INTR = (1 << 3), /* device asserts INTRQ when ready for CDB */
ATA_DEV_UNKNOWN = 0, /* unknown device */
ATA_DEV_ATA = 1, /* ATA device */
@ -115,8 +116,6 @@ enum {
ATA_FLAG_MMIO = (1 << 6), /* use MMIO, not PIO */
ATA_FLAG_SATA_RESET = (1 << 7), /* use COMRESET */
ATA_FLAG_PIO_DMA = (1 << 8), /* PIO cmds via DMA */
ATA_FLAG_NOINTR = (1 << 9), /* FIXME: Remove this once
* proper HSM is in place. */
ATA_QCFLAG_ACTIVE = (1 << 1), /* cmd not yet ack'd to scsi lyer */
ATA_QCFLAG_SG = (1 << 3), /* have s/g table? */
@ -165,6 +164,7 @@ enum hsm_task_states {
HSM_ST_LAST,
HSM_ST_LAST_POLL,
HSM_ST_ERR,
HSM_ST_FIRST,
};
/* forward declarations */