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Commit 8cbd6df1 authored by Albert Lee's avatar Albert Lee Committed by Jeff Garzik
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[PATCH] libata CHS: calculate read/write commands and protocol on the fly (revise #6) 



     - merge ata_prot_to_cmd() and ata_dev_set_protocol() as
       ata_rwcmd_protocol()
     - pave road for read/write multiple support
     - remove usage of pre-cached command and protocol values and call
       ata_rwcmd_protocol() instead

Signed-off-by: default avatarAlbert Lee <albertcc@tw.ibm.com>

==============
Signed-off-by: default avatarJeff Garzik <jgarzik@pobox.com>
parent 07506697

drivers/scsi/libata-core.c

+37 −68
Original line number Diff line number Diff line
@@ -616,79 +616,53 @@ void ata_tf_from_fis(u8 *fis, struct ata_taskfile *tf) 
	tf->hob_nsect	= fis[13];

}



/**

 *	ata_prot_to_cmd - determine which read/write opcodes to use

 *	@protocol: ATA_PROT_xxx taskfile protocol

 *	@lba48: true is lba48 is present

 *

 *	Given necessary input, determine which read/write commands

 *	to use to transfer data.

 *

 *	LOCKING:

 *	None.

 */

static int ata_prot_to_cmd(int protocol, int lba48)

{

	int rcmd = 0, wcmd = 0;



	switch (protocol) {

	case ATA_PROT_PIO:

		if (lba48) {

			rcmd = ATA_CMD_PIO_READ_EXT;

			wcmd = ATA_CMD_PIO_WRITE_EXT;

		} else {

			rcmd = ATA_CMD_PIO_READ;

			wcmd = ATA_CMD_PIO_WRITE;

		}

		break;



	case ATA_PROT_DMA:

		if (lba48) {

			rcmd = ATA_CMD_READ_EXT;

			wcmd = ATA_CMD_WRITE_EXT;

		} else {

			rcmd = ATA_CMD_READ;

			wcmd = ATA_CMD_WRITE;

		}

		break;



	default:

		return -1;

	}



	return rcmd | (wcmd << 8);

}

static const u8 ata_rw_cmds[] = {

	/* pio multi */

	ATA_CMD_READ_MULTI,

	ATA_CMD_WRITE_MULTI,

	ATA_CMD_READ_MULTI_EXT,

	ATA_CMD_WRITE_MULTI_EXT,

	/* pio */

	ATA_CMD_PIO_READ,

	ATA_CMD_PIO_WRITE,

	ATA_CMD_PIO_READ_EXT,

	ATA_CMD_PIO_WRITE_EXT,

	/* dma */

	ATA_CMD_READ,

	ATA_CMD_WRITE,

	ATA_CMD_READ_EXT,

	ATA_CMD_WRITE_EXT

};



/**

 *	ata_dev_set_protocol - set taskfile protocol and r/w commands

 *	@dev: device to examine and configure

 *	ata_rwcmd_protocol - set taskfile r/w commands and protocol

 *	@qc: command to examine and configure

 *

 *	Examine the device configuration, after we have

 *	read the identify-device page and configured the

 *	data transfer mode.  Set internal state related to

 *	the ATA taskfile protocol (pio, pio mult, dma, etc.)

 *	and calculate the proper read/write commands to use.

 *	Examine the device configuration and tf->flags to calculate 

 *	the proper read/write commands and protocol to use.

 *

 *	LOCKING:

 *	caller.

 */

static void ata_dev_set_protocol(struct ata_device *dev)

void ata_rwcmd_protocol(struct ata_queued_cmd *qc)

{

	int pio = (dev->flags & ATA_DFLAG_PIO);

	int lba48 = (dev->flags & ATA_DFLAG_LBA48);

	int proto, cmd;

	struct ata_taskfile *tf = &qc->tf;

	struct ata_device *dev = qc->dev;



	if (pio)

		proto = dev->xfer_protocol = ATA_PROT_PIO;

	else

		proto = dev->xfer_protocol = ATA_PROT_DMA;

	int index, lba48, write;

 

	cmd = ata_prot_to_cmd(proto, lba48);

	if (cmd < 0)

		BUG();

	lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;

	write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;



	if (dev->flags & ATA_DFLAG_PIO) {

		tf->protocol = ATA_PROT_PIO;

		index = dev->multi_count ? 0 : 4;

	} else {

		tf->protocol = ATA_PROT_DMA;

		index = 8;

	}



	dev->read_cmd = cmd & 0xff;

	dev->write_cmd = (cmd >> 8) & 0xff;

	tf->command = ata_rw_cmds[index + lba48 + write];

}



static const char * xfer_mode_str[] = {
@@ -1641,7 +1615,7 @@ static void ata_host_set_dma(struct ata_port *ap, u8 xfer_mode, 
 */

static void ata_set_mode(struct ata_port *ap)

{

	unsigned int i, xfer_shift;

	unsigned int xfer_shift;

	u8 xfer_mode;

	int rc;
@@ -1670,11 +1644,6 @@ static void ata_set_mode(struct ata_port *ap) 
	if (ap->ops->post_set_mode)

		ap->ops->post_set_mode(ap);



	for (i = 0; i < 2; i++) {

		struct ata_device *dev = &ap->device[i];

		ata_dev_set_protocol(dev);

	}



	return;



err_out:

drivers/scsi/libata-scsi.c

+6 −7
Original line number Diff line number Diff line
@@ -742,15 +742,10 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, u8 *scsicmd) 
	u32 n_block;



	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;

	tf->protocol = qc->dev->xfer_protocol;



	if (scsicmd[0] == READ_10 || scsicmd[0] == READ_6 ||

	    scsicmd[0] == READ_16) {

		tf->command = qc->dev->read_cmd;

	} else {

		tf->command = qc->dev->write_cmd;

	if (scsicmd[0] == WRITE_10 || scsicmd[0] == WRITE_6 ||

	    scsicmd[0] == WRITE_16)

		tf->flags |= ATA_TFLAG_WRITE;

	}



	/* Calculate the SCSI LBA and transfer length. */

	switch (scsicmd[0]) {
@@ -812,6 +807,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, u8 *scsicmd) 
			tf->device |= (block >> 24) & 0xf;

		}



		ata_rwcmd_protocol(qc);



		qc->nsect = n_block;

		tf->nsect = n_block & 0xff;
@@ -828,6 +825,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, u8 *scsicmd) 
		if ((block >> 28) || (n_block > 256))

			goto out_of_range;



		ata_rwcmd_protocol(qc);



		/* Convert LBA to CHS */

		track = (u32)block / dev->sectors;

		cyl   = track / dev->heads;

drivers/scsi/libata.h

+1 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ extern int atapi_enabled; 
extern int ata_qc_complete_noop(struct ata_queued_cmd *qc, u8 drv_stat);

extern struct ata_queued_cmd *ata_qc_new_init(struct ata_port *ap,

				      struct ata_device *dev);

extern void ata_rwcmd_protocol(struct ata_queued_cmd *qc);

extern void ata_qc_free(struct ata_queued_cmd *qc);

extern int ata_qc_issue(struct ata_queued_cmd *qc);

extern int ata_check_atapi_dma(struct ata_queued_cmd *qc);

include/linux/ata.h

+4 −0
Original line number Diff line number Diff line
@@ -128,6 +128,10 @@ enum { 
	ATA_CMD_PIO_READ_EXT	= 0x24,

	ATA_CMD_PIO_WRITE	= 0x30,

	ATA_CMD_PIO_WRITE_EXT	= 0x34,

	ATA_CMD_READ_MULTI	= 0xC4,

	ATA_CMD_READ_MULTI_EXT	= 0x29,

	ATA_CMD_WRITE_MULTI	= 0xC5,

	ATA_CMD_WRITE_MULTI_EXT	= 0x39,

	ATA_CMD_SET_FEATURES	= 0xEF,

	ATA_CMD_PACKET		= 0xA0,

	ATA_CMD_VERIFY		= 0x40,

include/linux/libata.h

+2 −4
Original line number Diff line number Diff line
@@ -283,10 +283,8 @@ struct ata_device { 
	u8			xfer_mode;

	unsigned int		xfer_shift;	/* ATA_SHIFT_xxx */



	/* cache info about current transfer mode */

	u8			xfer_protocol;	/* taskfile xfer protocol */

	u8			read_cmd;	/* opcode to use on read */

	u8			write_cmd;	/* opcode to use on write */

	unsigned int		multi_count;	/* sectors count for

						   READ/WRITE MULTIPLE */



	/* for CHS addressing */

	u16			cylinders;	/* Number of cylinders */