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Commit c91af2c8 authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
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[PATCH] libata: pass qc around intead of ap during PIO 



The current code passes pointer to ap around and repeatedly performs
ata_qc_from_tag() to access the ongoing qc.  This is unnatural and
makes EH synchronization cumbersome.  Make PIO codes deal with qc
instead of ap.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 27197367

drivers/scsi/libata-core.c

+26 −45
Original line number Diff line number Diff line
@@ -3416,7 +3416,7 @@ void ata_poll_qc_complete(struct ata_queued_cmd *qc) 


/**

 *	ata_pio_poll - poll using PIO, depending on current state

 *	@ap: the target ata_port

 *	@qc: qc in progress

 *

 *	LOCKING:

 *	None.  (executing in kernel thread context)
@@ -3424,17 +3424,13 @@ void ata_poll_qc_complete(struct ata_queued_cmd *qc) 
 *	RETURNS:

 *	timeout value to use

 */



static unsigned long ata_pio_poll(struct ata_port *ap)

static unsigned long ata_pio_poll(struct ata_queued_cmd *qc)

{

	struct ata_queued_cmd *qc;

	struct ata_port *ap = qc->ap;

	u8 status;

	unsigned int poll_state = HSM_ST_UNKNOWN;

	unsigned int reg_state = HSM_ST_UNKNOWN;



	qc = ata_qc_from_tag(ap, ap->active_tag);

	WARN_ON(qc == NULL);



	switch (ap->hsm_task_state) {

	case HSM_ST:

	case HSM_ST_POLL:
@@ -3468,7 +3464,7 @@ static unsigned long ata_pio_poll(struct ata_port *ap) 


/**

 *	ata_pio_complete - check if drive is busy or idle

 *	@ap: the target ata_port

 *	@qc: qc to complete

 *

 *	LOCKING:

 *	None.  (executing in kernel thread context)
@@ -3476,10 +3472,9 @@ static unsigned long ata_pio_poll(struct ata_port *ap) 
 *	RETURNS:

 *	Non-zero if qc completed, zero otherwise.

 */



static int ata_pio_complete (struct ata_port *ap)

static int ata_pio_complete(struct ata_queued_cmd *qc)

{

	struct ata_queued_cmd *qc;

	struct ata_port *ap = qc->ap;

	u8 drv_stat;



	/*
@@ -3500,9 +3495,6 @@ static int ata_pio_complete (struct ata_port *ap) 
		}

	}



	qc = ata_qc_from_tag(ap, ap->active_tag);

	WARN_ON(qc == NULL);



	drv_stat = ata_wait_idle(ap);

	if (!ata_ok(drv_stat)) {

		qc->err_mask |= __ac_err_mask(drv_stat);
@@ -3838,15 +3830,14 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc) 


/**

 *	ata_pio_block - start PIO on a block

 *	@ap: the target ata_port

 *	@qc: qc to transfer block for

 *

 *	LOCKING:

 *	None.  (executing in kernel thread context)

 */



static void ata_pio_block(struct ata_port *ap)

static void ata_pio_block(struct ata_queued_cmd *qc)

{

	struct ata_queued_cmd *qc;

	struct ata_port *ap = qc->ap;

	u8 status;



	/*
@@ -3868,9 +3859,6 @@ static void ata_pio_block(struct ata_port *ap) 
		}

	}



	qc = ata_qc_from_tag(ap, ap->active_tag);

	WARN_ON(qc == NULL);



	/* check error */

	if (status & (ATA_ERR | ATA_DF)) {

		qc->err_mask |= AC_ERR_DEV;
@@ -3899,12 +3887,9 @@ static void ata_pio_block(struct ata_port *ap) 
	}

}



static void ata_pio_error(struct ata_port *ap)

static void ata_pio_error(struct ata_queued_cmd *qc)

{

	struct ata_queued_cmd *qc;



	qc = ata_qc_from_tag(ap, ap->active_tag);

	WARN_ON(qc == NULL);

	struct ata_port *ap = qc->ap;



	if (qc->tf.command != ATA_CMD_PACKET)

		printk(KERN_WARNING "ata%u: dev %u PIO error\n",
@@ -3922,7 +3907,8 @@ static void ata_pio_error(struct ata_port *ap) 


static void ata_pio_task(void *_data)

{

	struct ata_port *ap = _data;

	struct ata_queued_cmd *qc = _data;

	struct ata_port *ap = qc->ap;

	unsigned long timeout;

	int qc_completed;
@@ -3935,33 +3921,33 @@ static void ata_pio_task(void *_data) 
		return;



	case HSM_ST:

		ata_pio_block(ap);

		ata_pio_block(qc);

		break;



	case HSM_ST_LAST:

		qc_completed = ata_pio_complete(ap);

		qc_completed = ata_pio_complete(qc);

		break;



	case HSM_ST_POLL:

	case HSM_ST_LAST_POLL:

		timeout = ata_pio_poll(ap);

		timeout = ata_pio_poll(qc);

		break;



	case HSM_ST_TMOUT:

	case HSM_ST_ERR:

		ata_pio_error(ap);

		ata_pio_error(qc);

		return;

	}



	if (timeout)

		ata_port_queue_task(ap, ata_pio_task, ap, timeout);

		ata_port_queue_task(ap, ata_pio_task, qc, timeout);

	else if (!qc_completed)

		goto fsm_start;

}



/**

 *	atapi_packet_task - Write CDB bytes to hardware

 *	@_data: Port to which ATAPI device is attached.

 *	@_data: qc in progress

 *

 *	When device has indicated its readiness to accept

 *	a CDB, this function is called.  Send the CDB.
@@ -3972,17 +3958,12 @@ static void ata_pio_task(void *_data) 
 *	LOCKING:

 *	Kernel thread context (may sleep)

 */



static void atapi_packet_task(void *_data)

{

	struct ata_port *ap = _data;

	struct ata_queued_cmd *qc;

	struct ata_queued_cmd *qc = _data;

	struct ata_port *ap = qc->ap;

	u8 status;



	qc = ata_qc_from_tag(ap, ap->active_tag);

	WARN_ON(qc == NULL);

	WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));



	/* sleep-wait for BSY to clear */

	DPRINTK("busy wait\n");

	if (ata_busy_sleep(ap, ATA_TMOUT_CDB_QUICK, ATA_TMOUT_CDB)) {
@@ -4022,7 +4003,7 @@ static void atapi_packet_task(void *_data) 


		/* PIO commands are handled by polling */

		ap->hsm_task_state = HSM_ST;

		ata_port_queue_task(ap, ata_pio_task, ap, 0);

		ata_port_queue_task(ap, ata_pio_task, qc, 0);

	}



	return;
@@ -4328,26 +4309,26 @@ unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc) 
		ata_qc_set_polling(qc);

		ata_tf_to_host(ap, &qc->tf);

		ap->hsm_task_state = HSM_ST;

		ata_port_queue_task(ap, ata_pio_task, ap, 0);

		ata_port_queue_task(ap, ata_pio_task, qc, 0);

		break;



	case ATA_PROT_ATAPI:

		ata_qc_set_polling(qc);

		ata_tf_to_host(ap, &qc->tf);

		ata_port_queue_task(ap, atapi_packet_task, ap, 0);

		ata_port_queue_task(ap, atapi_packet_task, qc, 0);

		break;



	case ATA_PROT_ATAPI_NODATA:

		ap->flags |= ATA_FLAG_NOINTR;

		ata_tf_to_host(ap, &qc->tf);

		ata_port_queue_task(ap, atapi_packet_task, ap, 0);

		ata_port_queue_task(ap, atapi_packet_task, qc, 0);

		break;



	case ATA_PROT_ATAPI_DMA:

		ap->flags |= ATA_FLAG_NOINTR;

		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */

		ap->ops->bmdma_setup(qc);	    /* set up bmdma */

		ata_port_queue_task(ap, atapi_packet_task, ap, 0);

		ata_port_queue_task(ap, atapi_packet_task, qc, 0);

		break;



	default: