[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: Tejun Heo <htejun@gmail.com>
Cc: Carlos Pardo <Carlos.Pardo@siliconimage.com>
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 56d7e1e..7ff1adf 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1698,6 +1698,22 @@
}
/**
+ * 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.
* @rbuf: Response buffer, to which simulated SCSI cmd output is sent.
@@ -2156,67 +2172,42 @@
* 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;