Commit 6a36261e authored by Tejun Heo's avatar Tejun Heo
Browse files

[PATCH] libata: fix READ CAPACITY simulation 



* READ CAPACITY (16) implementation fixed.  Result was shifted by two
  bytes.  Carlos Pardo spotted this problem and submitted preliminary
  patch.  Capacity => 2TB is handled correctly now.  (verifid w/ fake
  capacity)

* Use dev->n_sectors instead of re-reading directly from ID data.

* Define and use ATA_SCSI_RBUF_SET() which considers rbuf length.
  This should be done for all simulation functions.  Userland can
  issue any simulated command with arbitrary buffer length.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Cc: Carlos Pardo <Carlos.Pardo@siliconimage.com>
parent 3d3cca37

drivers/ata/libata-scsi.c

+36 −45
Original line number Diff line number Diff line
@@ -1697,6 +1697,22 @@ void ata_scsi_rbuf_fill(struct ata_scsi_args *args, 
	args->done(cmd);

}



/**

 *	ATA_SCSI_RBUF_SET - helper to set values in SCSI response buffer

 *	@idx: byte index into SCSI response buffer

 *	@val: value to set

 *

 *	To be used by SCSI command simulator functions.  This macros

 *	expects two local variables, u8 *rbuf and unsigned int buflen,

 *	are in scope.

 *

 *	LOCKING:

 *	None.

 */

#define ATA_SCSI_RBUF_SET(idx, val) do { \

		if ((idx) < buflen) rbuf[(idx)] = (u8)(val); \

	} while (0)



/**

 *	ata_scsiop_inq_std - Simulate INQUIRY command

 *	@args: device IDENTIFY data / SCSI command of interest.
@@ -2156,67 +2172,42 @@ saving_not_supp: 
 *	Simulate READ CAPACITY commands.

 *

 *	LOCKING:

 *	spin_lock_irqsave(host lock)

 *	None.

 */



unsigned int ata_scsiop_read_cap(struct ata_scsi_args *args, u8 *rbuf,

			        unsigned int buflen)

{

	u64 n_sectors;

	u32 tmp;

	u64 last_lba = args->dev->n_sectors - 1; /* LBA of the last block */



	VPRINTK("ENTER\n");



	if (ata_id_has_lba(args->id)) {

		if (ata_id_has_lba48(args->id))

			n_sectors = ata_id_u64(args->id, 100);

		else

			n_sectors = ata_id_u32(args->id, 60);

	} else {

		/* CHS default translation */

		n_sectors = args->id[1] * args->id[3] * args->id[6];



		if (ata_id_current_chs_valid(args->id))

			/* CHS current translation */

			n_sectors = ata_id_u32(args->id, 57);

	}



	n_sectors--;		/* ATA TotalUserSectors - 1 */



	if (args->cmd->cmnd[0] == READ_CAPACITY) {

		if( n_sectors >= 0xffffffffULL )

			tmp = 0xffffffff ;  /* Return max count on overflow */

		else

			tmp = n_sectors ;

		if (last_lba >= 0xffffffffULL)

			last_lba = 0xffffffff;



		/* sector count, 32-bit */

		rbuf[0] = tmp >> (8 * 3);

		rbuf[1] = tmp >> (8 * 2);

		rbuf[2] = tmp >> (8 * 1);

		rbuf[3] = tmp;

		ATA_SCSI_RBUF_SET(0, last_lba >> (8 * 3));

		ATA_SCSI_RBUF_SET(1, last_lba >> (8 * 2));

		ATA_SCSI_RBUF_SET(2, last_lba >> (8 * 1));

		ATA_SCSI_RBUF_SET(3, last_lba);



		/* sector size */

		tmp = ATA_SECT_SIZE;

		rbuf[6] = tmp >> 8;

		rbuf[7] = tmp;



		ATA_SCSI_RBUF_SET(6, ATA_SECT_SIZE >> 8);

		ATA_SCSI_RBUF_SET(7, ATA_SECT_SIZE);

	} else {

		/* sector count, 64-bit */

		tmp = n_sectors >> (8 * 4);

		rbuf[2] = tmp >> (8 * 3);

		rbuf[3] = tmp >> (8 * 2);

		rbuf[4] = tmp >> (8 * 1);

		rbuf[5] = tmp;

		tmp = n_sectors;

		rbuf[6] = tmp >> (8 * 3);

		rbuf[7] = tmp >> (8 * 2);

		rbuf[8] = tmp >> (8 * 1);

		rbuf[9] = tmp;

		ATA_SCSI_RBUF_SET(0, last_lba >> (8 * 7));

		ATA_SCSI_RBUF_SET(1, last_lba >> (8 * 6));

		ATA_SCSI_RBUF_SET(2, last_lba >> (8 * 5));

		ATA_SCSI_RBUF_SET(3, last_lba >> (8 * 4));

		ATA_SCSI_RBUF_SET(4, last_lba >> (8 * 3));

		ATA_SCSI_RBUF_SET(5, last_lba >> (8 * 2));

		ATA_SCSI_RBUF_SET(6, last_lba >> (8 * 1));

		ATA_SCSI_RBUF_SET(7, last_lba);



		/* sector size */

		tmp = ATA_SECT_SIZE;

		rbuf[12] = tmp >> 8;

		rbuf[13] = tmp;

		ATA_SCSI_RBUF_SET(10, ATA_SECT_SIZE >> 8);

		ATA_SCSI_RBUF_SET(11, ATA_SECT_SIZE);

	}



	return 0;

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