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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/scsi/osst_options.h
Initial import
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+/*
+ The compile-time configurable defaults for the Linux SCSI tape driver.
+
+ Copyright 1995 Kai Makisara.
+
+ Last modified: Wed Sep 2 21:24:07 1998 by root@home
+
+ Changed (and renamed) for OnStream SCSI drives garloff@suse.de
+ 2000-06-21
+
+ $Header: /cvsroot/osst/Driver/osst_options.h,v 1.6 2003/12/23 14:22:12 wriede Exp $
+*/
+
+#ifndef _OSST_OPTIONS_H
+#define _OSST_OPTIONS_H
+
+/* The minimum limit for the number of SCSI tape devices is determined by
+ OSST_MAX_TAPES. If the number of tape devices and the "slack" defined by
+ OSST_EXTRA_DEVS exceeds OSST_MAX_TAPES, the large number is used. */
+#define OSST_MAX_TAPES 4
+
+/* If OSST_IN_FILE_POS is nonzero, the driver positions the tape after the
+ record been read by the user program even if the tape has moved further
+ because of buffered reads. Should be set to zero to support also drives
+ that can't space backwards over records. NOTE: The tape will be
+ spaced backwards over an "accidentally" crossed filemark in any case. */
+#define OSST_IN_FILE_POS 1
+
+/* The tape driver buffer size in kilobytes. */
+/* Don't change, as this is the HW blocksize */
+#define OSST_BUFFER_BLOCKS 32
+
+/* The number of kilobytes of data in the buffer that triggers an
+ asynchronous write in fixed block mode. See also OSST_ASYNC_WRITES
+ below. */
+#define OSST_WRITE_THRESHOLD_BLOCKS 32
+
+/* OSST_EOM_RESERVE defines the number of frames are kept in reserve for
+ * * write error recovery when writing near end of medium. ENOSPC is returned
+ * * when write() is called and the tape write position is within this number
+ * * of blocks from the tape capacity. */
+#define OSST_EOM_RESERVE 300
+
+/* The maximum number of tape buffers the driver allocates. The number
+ is also constrained by the number of drives detected. Determines the
+ maximum number of concurrently active tape drives. */
+#define OSST_MAX_BUFFERS OSST_MAX_TAPES
+
+/* Maximum number of scatter/gather segments */
+/* Fit one buffer in pages and add one for the AUX header */
+#define OSST_MAX_SG (((OSST_BUFFER_BLOCKS*1024) / PAGE_SIZE) + 1)
+
+/* The number of scatter/gather segments to allocate at first try (must be
+ smaller or equal to the maximum). */
+#define OSST_FIRST_SG ((OSST_BUFFER_BLOCKS*1024) / PAGE_SIZE)
+
+/* The size of the first scatter/gather segments (determines the maximum block
+ size for SCSI adapters not supporting scatter/gather). The default is set
+ to try to allocate the buffer as one chunk. */
+#define OSST_FIRST_ORDER (15-PAGE_SHIFT)
+
+
+/* The following lines define defaults for properties that can be set
+ separately for each drive using the MTSTOPTIONS ioctl. */
+
+/* If OSST_TWO_FM is non-zero, the driver writes two filemarks after a
+ file being written. Some drives can't handle two filemarks at the
+ end of data. */
+#define OSST_TWO_FM 0
+
+/* If OSST_BUFFER_WRITES is non-zero, writes in fixed block mode are
+ buffered until the driver buffer is full or asynchronous write is
+ triggered. */
+#define OSST_BUFFER_WRITES 1
+
+/* If OSST_ASYNC_WRITES is non-zero, the SCSI write command may be started
+ without waiting for it to finish. May cause problems in multiple
+ tape backups. */
+#define OSST_ASYNC_WRITES 1
+
+/* If OSST_READ_AHEAD is non-zero, blocks are read ahead in fixed block
+ mode. */
+#define OSST_READ_AHEAD 1
+
+/* If OSST_AUTO_LOCK is non-zero, the drive door is locked at the first
+ read or write command after the device is opened. The door is opened
+ when the device is closed. */
+#define OSST_AUTO_LOCK 0
+
+/* If OSST_FAST_MTEOM is non-zero, the MTEOM ioctl is done using the
+ direct SCSI command. The file number status is lost but this method
+ is fast with some drives. Otherwise MTEOM is done by spacing over
+ files and the file number status is retained. */
+#define OSST_FAST_MTEOM 0
+
+/* If OSST_SCSI2LOGICAL is nonzero, the logical block addresses are used for
+ MTIOCPOS and MTSEEK by default. Vendor addresses are used if OSST_SCSI2LOGICAL
+ is zero. */
+#define OSST_SCSI2LOGICAL 0
+
+/* If OSST_SYSV is non-zero, the tape behaves according to the SYS V semantics.
+ The default is BSD semantics. */
+#define OSST_SYSV 0
+
+
+#endif