Introduction¶

BusLogic, Inc. designed and manufactured a variety of high performance SCSIhost adapters which share a common programming interface across a diversecollection of bus architectures by virtue of their MultiMaster ASIC technology.BusLogic was acquired by Mylex Corporation in February 1996, but the productssupported by this driver originated under the BusLogic name and so that name isretained in the source code and documentation.

This driver supports all present BusLogic MultiMaster Host Adapters, and shouldsupport any future MultiMaster designs with little or no modification. Morerecently, BusLogic introduced the FlashPoint Host Adapters, which are lesscostly and rely on the host CPU, rather than including an onboard processor.Despite not having an onboard CPU, the FlashPoint Host Adapters perform verywell and have very low command latency. BusLogic has recently provided me withthe FlashPoint Driver Developer’s Kit, which comprises documentation and freelyredistributable source code for the FlashPoint SCCB Manager. The SCCB Manageris the library of code that runs on the host CPU and performs functionsanalogous to the firmware on the MultiMaster Host Adapters. Thanks to theirhaving provided the SCCB Manager, this driver now supports the FlashPoint HostAdapters as well.

My primary goals in writing this completely new BusLogic driver for Linux areto achieve the full performance that BusLogic SCSI Host Adapters and modernSCSI peripherals are capable of, and to provide a highly robust driver that canbe depended upon for high performance mission critical applications. All ofthe major performance features can be configured from the Linux kernel commandline or at module initialization time, allowing individual installations totune driver performance and error recovery to their particular needs.

The latest information on Linux support for BusLogic SCSI Host Adapters, aswell as the most recent release of this driver and the latest firmware for theBT-948/958/958D, will always be available from my Linux Home Page at URL“http://sourceforge.net/projects/dandelion/”.

Bug reports should be sent via electronic mail to “lnz@dandelion.com”. Pleaseinclude with the bug report the complete configuration messages reported by thedriver and SCSI subsystem at startup, along with any subsequent system messagesrelevant to SCSI operations, and a detailed description of your system’shardware configuration.

Mylex has been an excellent company to work with and I highly recommend theirproducts to the Linux community. In November 1995, I was offered theopportunity to become a beta test site for their latest MultiMaster product,the BT-948 PCI Ultra SCSI Host Adapter, and then again for the BT-958 PCI WideUltra SCSI Host Adapter in January 1996. This was mutually beneficial sinceMylex received a degree and kind of testing that their own testing group cannotreadily achieve, and the Linux community has available high performance hostadapters that have been well tested with Linux even before being brought tomarket. This relationship has also given me the opportunity to interactdirectly with their technical staff, to understand more about the internalworkings of their products, and in turn to educate them about the needs andpotential of the Linux community.

More recently, Mylex has reaffirmed the company’s interest in supporting theLinux community, and I am now working on a Linux driver for the DAC960 PCI RAIDControllers. Mylex’s interest and support is greatly appreciated.

Unlike some other vendors, if you contact Mylex Technical Support with aproblem and are running Linux, they will not tell you that your use of theirproducts is unsupported. Their latest product marketing literature even states“Mylex SCSI host adapters are compatible with all major operating systemsincluding: … Linux …”.

Mylex Corporation is located at 34551 Ardenwood Blvd., Fremont, California94555, USA and can be reached at 510/796-6100 or on the World Wide Web athttp://www.mylex.com. Mylex HBA Technical Support can be reached by electronicmail attechsup@mylex.com, by Voice at 510/608-2400, or by FAX at 510/745-7715.Contact information for offices in Europe and Japan is available on the Website.

Driver Features¶

Supported Host Adapters¶

The following list comprises the supported BusLogic SCSI Host Adapters as ofthe date of this document. It is recommended that anyone purchasing a BusLogicHost Adapter not in the following table contact the author beforehand to verifythat it is or will be supported.

FlashPoint Series PCI Host Adapters:

MultiMaster “W” Series Host Adapters:

MultiMaster “C” Series Host Adapters:

MultiMaster “S” Series Host Adapters:

MultiMaster “A” Series Host Adapters:

AMI FastDisk Host Adapters that are true BusLogic MultiMaster clones are alsosupported by this driver.

BusLogic SCSI Host Adapters are available packaged both as bare boards and asretail kits. The BT- model numbers above refer to the bare board packaging.The retail kit model numbers are found by replacing BT- with KT- in the abovelist. The retail kit includes the bare board and manual as well as cabling anddriver media and documentation that are not provided with bare boards.

FlashPoint Installation Notes¶

BT-948/958/958D Installation Notes¶

The BT-948/958/958D PCI Ultra SCSI Host Adapters have some features which mayrequire attention in some circumstances when installing Linux.

Driver Options¶

BusLogic Driver Options may be specified either via the Linux Kernel CommandLine or via the Loadable Kernel Module Installation Facility. Driver Optionsfor multiple host adapters may be specified either by separating the optionstrings by a semicolon, or by specifying multiple “BusLogic=” strings on thecommand line. Individual option specifications for a single host adapter areseparated by commas. The Probing and Debugging Options apply to all hostadapters whereas the remaining options apply individually only to theselected host adapter.

The BusLogic Driver Probing Options comprise the following:

IO:<integer>

The “IO:” option specifies an ISA I/O Address to be probed for a non-PCIMultiMaster Host Adapter. If neither “IO:” nor “NoProbeISA” options arespecified, then the standard list of BusLogic MultiMaster ISA I/O Addresseswill be probed (0x330, 0x334, 0x230, 0x234, 0x130, and 0x134). Multiple“IO:” options may be specified to precisely determine the I/O Addresses tobe probed, but the probe order will always follow the standard list.

NoProbe

The “NoProbe” option disables all probing and therefore no BusLogic HostAdapters will be detected.

NoProbeISA

The “NoProbeISA” option disables probing of the standard BusLogic ISA I/OAddresses and therefore only PCI MultiMaster and FlashPoint Host Adapterswill be detected.

NoProbePCI

The “NoProbePCI” options disables the interrogation of PCI ConfigurationSpace and therefore only ISA Multimaster Host Adapters will be detected, aswell as PCI Multimaster Host Adapters that have their ISA Compatible I/OPort set to “Primary” or “Alternate”.

NoSortPCI

The “NoSortPCI” option forces PCI MultiMaster Host Adapters to beenumerated in the order provided by the PCI BIOS, ignoring any setting ofthe AutoSCSI “Use Bus And Device # For PCI Scanning Seq.” option.

MultiMasterFirst

The “MultiMasterFirst” option forces MultiMaster Host Adapters to be probedbefore FlashPoint Host Adapters. By default, if both FlashPoint and PCIMultiMaster Host Adapters are present, this driver will probe forFlashPoint Host Adapters first unless the BIOS primary disk is controlledby the first PCI MultiMaster Host Adapter, in which case MultiMaster HostAdapters will be probed first.

FlashPointFirst

The “FlashPointFirst” option forces FlashPoint Host Adapters to be probedbefore MultiMaster Host Adapters.

The BusLogic Driver Tagged Queuing Options allow for explicitly specifyingthe Queue Depth and whether Tagged Queuing is permitted for each TargetDevice (assuming that the Target Device supports Tagged Queuing). The QueueDepth is the number of SCSI Commands that are allowed to be concurrentlypresented for execution (either to the Host Adapter or Target Device). Notethat explicitly enabling Tagged Queuing may lead to problems; the option toenable or disable Tagged Queuing is provided primarily to allow disablingTagged Queuing on Target Devices that do not implement it correctly. Thefollowing options are available:

QueueDepth:<integer>

The “QueueDepth:” or QD:” option specifies the Queue Depth to use for allTarget Devices that support Tagged Queuing, as well as the maximum QueueDepth for devices that do not support Tagged Queuing. If no Queue Depthoption is provided, the Queue Depth will be determined automatically basedon the Host Adapter’s Total Queue Depth and the number, type, speed, andcapabilities of the detected Target Devices. For Host Adapters thatrequire ISA Bounce Buffers, the Queue Depth is automatically set by defaultto BusLogic_TaggedQueueDepthBB or BusLogic_UntaggedQueueDepthBB to avoidexcessive preallocation of DMA Bounce Buffer memory. Target Devices thatdo not support Tagged Queuing always have their Queue Depth set toBusLogic_UntaggedQueueDepth or BusLogic_UntaggedQueueDepthBB, unless alower Queue Depth option is provided. A Queue Depth of 1 automaticallydisables Tagged Queuing.

QueueDepth:[<integer>,<integer>…]

The “QueueDepth:[…]” or “QD:[…]” option specifies the Queue Depthindividually for each Target Device. If an <integer> is omitted, theassociated Target Device will have its Queue Depth selected automatically.

TaggedQueuing:Default

The “TaggedQueuing:Default” or “TQ:Default” option permits Tagged Queuingbased on the firmware version of the BusLogic Host Adapter and based onwhether the Queue Depth allows queuing multiple commands.

TaggedQueuing:Enable

The “TaggedQueuing:Enable” or “TQ:Enable” option enables Tagged Queuing forall Target Devices on this Host Adapter, overriding any limitation thatwould otherwise be imposed based on the Host Adapter firmware version.

TaggedQueuing:Disable

The “TaggedQueuing:Disable” or “TQ:Disable” option disables Tagged Queuingfor all Target Devices on this Host Adapter.

TaggedQueuing:<Target-Spec>

The “TaggedQueuing:<Target-Spec>” or “TQ:<Target-Spec>” option controlsTagged Queuing individually for each Target Device. <Target-Spec> is asequence of “Y”, “N”, and “X” characters. “Y” enables Tagged Queuing, “N”disables Tagged Queuing, and “X” accepts the default based on the firmwareversion. The first character refers to Target Device 0, the second toTarget Device 1, and so on; if the sequence of “Y”, “N”, and “X” charactersdoes not cover all the Target Devices, unspecified characters are assumedto be “X”.

The BusLogic Driver Miscellaneous Options comprise the following:

BusSettleTime:<seconds>

The “BusSettleTime:” or “BST:” option specifies the Bus Settle Time inseconds. The Bus Settle Time is the amount of time to wait between a HostAdapter Hard Reset which initiates a SCSI Bus Reset and issuing any SCSICommands. If unspecified, it defaults to BusLogic_DefaultBusSettleTime.

InhibitTargetInquiry

The “InhibitTargetInquiry” option inhibits the execution of an InquireTarget Devices or Inquire Installed Devices command on MultiMaster HostAdapters. This may be necessary with some older Target Devices that do notrespond correctly when Logical Units above 0 are addressed.

The BusLogic Driver Debugging Options comprise the following:

TraceProbe

The “TraceProbe” option enables tracing of Host Adapter Probing.

TraceHardwareReset

The “TraceHardwareReset” option enables tracing of Host Adapter HardwareReset.

TraceConfiguration

The “TraceConfiguration” option enables tracing of Host AdapterConfiguration.

TraceErrors

The “TraceErrors” option enables tracing of SCSI Commands that return anerror from the Target Device. The CDB and Sense Data will be printed foreach SCSI Command that fails.

Debug

The “Debug” option enables all debugging options.

The following examples demonstrate setting the Queue Depth for Target Devices1 and 2 on the first host adapter to 7 and 15, the Queue Depth for all TargetDevices on the second host adapter to 31, and the Bus Settle Time on thesecond host adapter to 30 seconds.

Linux Kernel Command Line:

linux BusLogic=QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30

LILO Linux Boot Loader (in /etc/lilo.conf):

append = "BusLogic=QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30"

INSMOD Loadable Kernel Module Installation Facility:

insmod BusLogic.o \    'BusLogic="QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30"'

Driver Installation¶

This distribution was prepared for Linux kernel version 2.0.35, but should becompatible with 2.0.4 or any later 2.0 series kernel.

To install the new BusLogic SCSI driver, you may use the following commands,replacing “/usr/src” with wherever you keep your Linux kernel source tree:

cd /usr/srctar -xvzf BusLogic-2.0.15.tar.gzmv README.* LICENSE.* BusLogic.[ch] FlashPoint.c linux/drivers/scsipatch -p0 < BusLogic.patch (only for 2.0.33 and below)cd linuxmake configmake zImage

Then install “arch/x86/boot/zImage” as your standard kernel, run lilo ifappropriate, and reboot.

BusLogic Announcements Mailing List¶

The BusLogic Announcements Mailing List provides a forum for informing Linuxusers of new driver releases and other announcements regarding Linux supportfor BusLogic SCSI Host Adapters. To join the mailing list, send a message to“buslogic-announce-request@dandelion.com” with the line “subscribe” in themessage body.