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Commit d277064e authored by Matthieu CASTET's avatar Matthieu CASTET Committed by Greg Kroah-Hartman
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USB: mass storage: emulation of sat scsi_pass_thru with ATACB 

I have got a cypress usb-ide bridge and I would like to tune or monitor
my disk with tools like hdparm, hddtemp or smartctl.

My controller support a way to send raw ATA command to the disk with
something call atacb (see
http://download.cypress.com.edgesuite.net/design_resources/datasheets/contents/cy7c68300c_8.pdf

).

Atacb support can be added for each application, but there is some disadvantages :
- all application need to be patched
- A race is possible if there other accesses, because the emulation can
be split in 2 atacb scsi transactions. One for sending the command, one
for reading the register (if ck_cond is set). 

I have implemented the emulation in usb-storage with a special proto_handler,
and an unsual entry.

Signed-off-by: default avatarMatthieu CASTET <castet.matthieu@free.fr>
Signed-off-by: default avatarMatthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent dda43a0e

drivers/usb/storage/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -145,6 +145,17 @@ config USB_STORAGE_KARMA 
	  on the resulting scsi device node returns the Karma to normal

	  operation.



config USB_STORAGE_CYPRESS_ATACB

	bool "SAT emulation on Cypress USB/ATA Bridge with ATACB"

	depends on USB_STORAGE

	---help---

	  Say Y here if you want to use SAT (ata pass through) on devices based

	  on the Cypress USB/ATA bridge supporting ATACB. This will allow you

	  to use tools to tune and monitor your drive (like hdparm or smartctl).



	  If you say no here your device will still work with the standard usb

	  mass storage class.



config USB_LIBUSUAL

	bool "The shared table of common (or usual) storage devices"

	depends on USB

drivers/usb/storage/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ usb-storage-obj-$(CONFIG_USB_STORAGE_JUMPSHOT) += jumpshot.o 
usb-storage-obj-$(CONFIG_USB_STORAGE_ALAUDA)	+= alauda.o

usb-storage-obj-$(CONFIG_USB_STORAGE_ONETOUCH)	+= onetouch.o

usb-storage-obj-$(CONFIG_USB_STORAGE_KARMA)	+= karma.o

usb-storage-obj-$(CONFIG_USB_STORAGE_CYPRESS_ATACB) += cypress_atacb.o



usb-storage-objs :=	scsiglue.o protocol.o transport.o usb.o \

			initializers.o $(usb-storage-obj-y)

drivers/usb/storage/cypress_atacb.c

0 → 100644
+200 −0
Original line number Diff line number Diff line 
/*

 * Support for emulating SAT (ata pass through) on devices based

 *       on the Cypress USB/ATA bridge supporting ATACB.

 *

 * Copyright (c) 2008 Matthieu Castet (castet.matthieu@free.fr)

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation; either version 2, or (at your option) any

 * later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 675 Mass Ave, Cambridge, MA 02139, USA.

 */



#include <scsi/scsi.h>

#include <scsi/scsi_cmnd.h>

#include <scsi/scsi_eh.h>

#include <linux/ata.h>



#include "usb.h"

#include "protocol.h"

#include "scsiglue.h"

#include "debug.h"



/*

 * ATACB is a protocol used on cypress usb<->ata bridge to

 * send raw ATA command over mass storage

 * There is a ATACB2 protocol that support LBA48 on newer chip.

 * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf

 * datasheet from cypress.com.

 */

void cypress_atacb_passthrough(struct scsi_cmnd *srb, struct us_data *us)

{

	unsigned char save_cmnd[MAX_COMMAND_SIZE];



	if (likely(srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)) {

		usb_stor_transparent_scsi_command(srb, us);

		return;

	}



	memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));

	memset(srb->cmnd, 0, sizeof(srb->cmnd));



	/* check if we support the command */

	if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */

		goto invalid_fld;

	/* check protocol */

	switch((save_cmnd[1] >> 1) & 0xf) {

		case 3: /*no DATA */

		case 4: /* PIO in */

		case 5: /* PIO out */

			break;

		default:

			goto invalid_fld;

	}



	/* first build the ATACB command */

	srb->cmd_len = 16;



	srb->cmnd[0] = 0x24; /* bVSCBSignature : vendor-specific command

	                        this value can change, but most(all ?) manufacturers

							keep the cypress default : 0x24 */

	srb->cmnd[1] = 0x24; /* bVSCBSubCommand : 0x24 for ATACB */



	srb->cmnd[3] = 0xff - 1; /* features, sector count, lba low, lba med

								lba high, device, command are valid */

	srb->cmnd[4] = 1; /* TransferBlockCount : 512 */



	if (save_cmnd[0] == ATA_16) {

		srb->cmnd[ 6] = save_cmnd[ 4]; /* features */

		srb->cmnd[ 7] = save_cmnd[ 6]; /* sector count */

		srb->cmnd[ 8] = save_cmnd[ 8]; /* lba low */

		srb->cmnd[ 9] = save_cmnd[10]; /* lba med */

		srb->cmnd[10] = save_cmnd[12]; /* lba high */

		srb->cmnd[11] = save_cmnd[13]; /* device */

		srb->cmnd[12] = save_cmnd[14]; /* command */



		if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */

			/* this could be supported by atacb2 */

			if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]

					|| save_cmnd[11])

				goto invalid_fld;

		}

	}

	else { /* ATA12 */

		srb->cmnd[ 6] = save_cmnd[3]; /* features */

		srb->cmnd[ 7] = save_cmnd[4]; /* sector count */

		srb->cmnd[ 8] = save_cmnd[5]; /* lba low */

		srb->cmnd[ 9] = save_cmnd[6]; /* lba med */

		srb->cmnd[10] = save_cmnd[7]; /* lba high */

		srb->cmnd[11] = save_cmnd[8]; /* device */

		srb->cmnd[12] = save_cmnd[9]; /* command */



	}

	/* Filter SET_FEATURES - XFER MODE command */

	if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)

			&& (srb->cmnd[6] == SETFEATURES_XFER))

		goto invalid_fld;



	if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)

		srb->cmnd[2] |= (1<<7); /* set  IdentifyPacketDevice for these cmds */





	usb_stor_transparent_scsi_command(srb, us);



	/* if the device doesn't support ATACB

	 */

	if (srb->result == SAM_STAT_CHECK_CONDITION &&

			memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,

				sizeof(usb_stor_sense_invalidCDB)) == 0) {

		US_DEBUGP("cypress atacb not supported ???\n");

		goto end;

	}



	/* if ck_cond flags is set, and there wasn't critical error,

	 * build the special sense

	 */

	if ((srb->result != (DID_ERROR << 16) &&

				srb->result != (DID_ABORT << 16)) &&

			save_cmnd[2] & 0x20) {

		struct scsi_eh_save ses;

		unsigned char regs[8];

		unsigned char *sb = srb->sense_buffer;

		unsigned char *desc = sb + 8;

		int tmp_result;



		/* build the command for

		 * reading the ATA registers */

		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, 0);

		srb->sdb.length = sizeof(regs);

		sg_init_one(&ses.sense_sgl, regs, srb->sdb.length);

		srb->sdb.table.sgl = &ses.sense_sgl;

		srb->sc_data_direction = DMA_FROM_DEVICE;

		srb->sdb.table.nents = 1;

		/* we use the same command as before, but we set

		 * the read taskfile bit, for not executing atacb command,

		 * but reading register selected in srb->cmnd[4]

		 */

		srb->cmnd[2] = 1;



		usb_stor_transparent_scsi_command(srb, us);

		tmp_result = srb->result;

		scsi_eh_restore_cmnd(srb, &ses);

		/* we fail to get registers, report invalid command */

		if (tmp_result != SAM_STAT_GOOD)

			goto invalid_fld;



		/* build the sense */

		memset(sb, 0, SCSI_SENSE_BUFFERSIZE);



		/* set sk, asc for a good command */

		sb[1] = RECOVERED_ERROR;

		sb[2] = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */

		sb[3] = 0x1D;



		/* XXX we should generate sk, asc, ascq from status and error

		 * regs

		 * (see 11.1 Error translation  ATA device error to SCSI error map)

		 * and ata_to_sense_error from libata.

		 */



		/* Sense data is current and format is descriptor. */

		sb[0] = 0x72;

		desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */



		/* set length of additional sense data */

		sb[7] = 14;

		desc[1] = 12;



		/* Copy registers into sense buffer. */

		desc[ 2] = 0x00;

		desc[ 3] = regs[1];  /* features */

		desc[ 5] = regs[2];  /* sector count */

		desc[ 7] = regs[3];  /* lba low */

		desc[ 9] = regs[4];  /* lba med */

		desc[11] = regs[5];  /* lba high */

		desc[12] = regs[6];  /* device */

		desc[13] = regs[7];  /* command */



		srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;

	}

	goto end;

invalid_fld:

	srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;



	memcpy(srb->sense_buffer,

			usb_stor_sense_invalidCDB,

			sizeof(usb_stor_sense_invalidCDB));

end:

	memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));

	if (srb->cmnd[0] == ATA_12)

		srb->cmd_len = 12;

}

drivers/usb/storage/cypress_atacb.h

0 → 100644
+25 −0
Original line number Diff line number Diff line 
/*

 * Support for emulating SAT (ata pass through) on devices based

 *       on the Cypress USB/ATA bridge supporting ATACB.

 *

 * Copyright (c) 2008 Matthieu Castet (castet.matthieu@free.fr)

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation; either version 2, or (at your option) any

 * later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 675 Mass Ave, Cambridge, MA 02139, USA.

 */



#ifndef _CYPRESS_ATACB_H_

#define _CYPRESS_ATACB_H_

extern void cypress_atacb_passthrough(struct scsi_cmnd*, struct us_data*);

#endif

drivers/usb/storage/scsiglue.c

+1 −1
Original line number Diff line number Diff line
@@ -132,7 +132,7 @@ static int slave_configure(struct scsi_device *sdev) 
		/* Disk-type devices use MODE SENSE(6) if the protocol

		 * (SubClass) is Transparent SCSI, otherwise they use

		 * MODE SENSE(10). */

		if (us->subclass != US_SC_SCSI)

		if (us->subclass != US_SC_SCSI && us->subclass != US_SC_CYP_ATACB)

			sdev->use_10_for_ms = 1;



		/* Many disks only accept MODE SENSE transfer lengths of