1 .. SPDX-License-Identifier: GPL-2.0
3 =========================================================
4 BusLogic MultiMaster and FlashPoint SCSI Driver for Linux
5 =========================================================
7 Version 2.0.15 for Linux 2.0
9 Version 2.1.15 for Linux 2.1
21 Copyright 1995-1998 by Leonard N. Zubkoff <lnz@dandelion.com>
27 BusLogic, Inc. designed and manufactured a variety of high performance SCSI
28 host adapters which share a common programming interface across a diverse
29 collection of bus architectures by virtue of their MultiMaster ASIC technology.
30 BusLogic was acquired by Mylex Corporation in February 1996, but the products
31 supported by this driver originated under the BusLogic name and so that name is
32 retained in the source code and documentation.
34 This driver supports all present BusLogic MultiMaster Host Adapters, and should
35 support any future MultiMaster designs with little or no modification. More
36 recently, BusLogic introduced the FlashPoint Host Adapters, which are less
37 costly and rely on the host CPU, rather than including an onboard processor.
38 Despite not having an onboard CPU, the FlashPoint Host Adapters perform very
39 well and have very low command latency. BusLogic has recently provided me with
40 the FlashPoint Driver Developer's Kit, which comprises documentation and freely
41 redistributable source code for the FlashPoint SCCB Manager. The SCCB Manager
42 is the library of code that runs on the host CPU and performs functions
43 analogous to the firmware on the MultiMaster Host Adapters. Thanks to their
44 having provided the SCCB Manager, this driver now supports the FlashPoint Host
47 My primary goals in writing this completely new BusLogic driver for Linux are
48 to achieve the full performance that BusLogic SCSI Host Adapters and modern
49 SCSI peripherals are capable of, and to provide a highly robust driver that can
50 be depended upon for high performance mission critical applications. All of
51 the major performance features can be configured from the Linux kernel command
52 line or at module initialization time, allowing individual installations to
53 tune driver performance and error recovery to their particular needs.
55 The latest information on Linux support for BusLogic SCSI Host Adapters, as
56 well as the most recent release of this driver and the latest firmware for the
57 BT-948/958/958D, will always be available from my Linux Home Page at URL
58 "http://sourceforge.net/projects/dandelion/".
60 Bug reports should be sent via electronic mail to "lnz@dandelion.com". Please
61 include with the bug report the complete configuration messages reported by the
62 driver and SCSI subsystem at startup, along with any subsequent system messages
63 relevant to SCSI operations, and a detailed description of your system's
64 hardware configuration.
66 Mylex has been an excellent company to work with and I highly recommend their
67 products to the Linux community. In November 1995, I was offered the
68 opportunity to become a beta test site for their latest MultiMaster product,
69 the BT-948 PCI Ultra SCSI Host Adapter, and then again for the BT-958 PCI Wide
70 Ultra SCSI Host Adapter in January 1996. This was mutually beneficial since
71 Mylex received a degree and kind of testing that their own testing group cannot
72 readily achieve, and the Linux community has available high performance host
73 adapters that have been well tested with Linux even before being brought to
74 market. This relationship has also given me the opportunity to interact
75 directly with their technical staff, to understand more about the internal
76 workings of their products, and in turn to educate them about the needs and
77 potential of the Linux community.
79 More recently, Mylex has reaffirmed the company's interest in supporting the
80 Linux community, and I am now working on a Linux driver for the DAC960 PCI RAID
81 Controllers. Mylex's interest and support is greatly appreciated.
83 Unlike some other vendors, if you contact Mylex Technical Support with a
84 problem and are running Linux, they will not tell you that your use of their
85 products is unsupported. Their latest product marketing literature even states
86 "Mylex SCSI host adapters are compatible with all major operating systems
87 including: ... Linux ...".
89 Mylex Corporation is located at 34551 Ardenwood Blvd., Fremont, California
90 94555, USA and can be reached at 510/796-6100 or on the World Wide Web at
91 http://www.mylex.com. Mylex HBA Technical Support can be reached by electronic
92 mail at techsup@mylex.com, by Voice at 510/608-2400, or by FAX at 510/745-7715.
93 Contact information for offices in Europe and Japan is available on the Web
100 Configuration Reporting and Testing
101 -----------------------------------
103 During system initialization, the driver reports extensively on the host
104 adapter hardware configuration, including the synchronous transfer parameters
105 requested and negotiated with each target device. AutoSCSI settings for
106 Synchronous Negotiation, Wide Negotiation, and Disconnect/Reconnect are
107 reported for each target device, as well as the status of Tagged Queuing.
108 If the same setting is in effect for all target devices, then a single word
109 or phrase is used; otherwise, a letter is provided for each target device to
110 indicate the individual status. The following examples
111 should clarify this reporting format:
113 Synchronous Negotiation: Ultra
115 Synchronous negotiation is enabled for all target devices and the host
116 adapter will attempt to negotiate for 20.0 mega-transfers/second.
118 Synchronous Negotiation: Fast
120 Synchronous negotiation is enabled for all target devices and the host
121 adapter will attempt to negotiate for 10.0 mega-transfers/second.
123 Synchronous Negotiation: Slow
125 Synchronous negotiation is enabled for all target devices and the host
126 adapter will attempt to negotiate for 5.0 mega-transfers/second.
128 Synchronous Negotiation: Disabled
130 Synchronous negotiation is disabled and all target devices are limited to
131 asynchronous operation.
133 Synchronous Negotiation: UFSNUUU#UUUUUUUU
135 Synchronous negotiation to Ultra speed is enabled for target devices 0
136 and 4 through 15, to Fast speed for target device 1, to Slow speed for
137 target device 2, and is not permitted to target device 3. The host
138 adapter's SCSI ID is represented by the "#".
140 The status of Wide Negotiation, Disconnect/Reconnect, and Tagged Queuing
141 are reported as "Enabled", Disabled", or a sequence of "Y" and "N" letters.
146 BusLogic SCSI Host Adapters directly implement SCSI-2 Tagged Queuing, and so
147 support has been included in the driver to utilize tagged queuing with any
148 target devices that report having the tagged queuing capability. Tagged
149 queuing allows for multiple outstanding commands to be issued to each target
150 device or logical unit, and can improve I/O performance substantially. In
151 addition, BusLogic's Strict Round Robin Mode is used to optimize host adapter
152 performance, and scatter/gather I/O can support as many segments as can be
153 effectively utilized by the Linux I/O subsystem. Control over the use of
154 tagged queuing for each target device as well as individual selection of the
155 tagged queue depth is available through driver options provided on the kernel
156 command line or at module initialization time. By default, the queue depth
157 is determined automatically based on the host adapter's total queue depth and
158 the number, type, speed, and capabilities of the target devices found. In
159 addition, tagged queuing is automatically disabled whenever the host adapter
160 firmware version is known not to implement it correctly, or whenever a tagged
161 queue depth of 1 is selected. Tagged queuing is also disabled for individual
162 target devices if disconnect/reconnect is disabled for that device.
167 The driver implements extensive error recovery procedures. When the higher
168 level parts of the SCSI subsystem request that a timed out command be reset,
169 a selection is made between a full host adapter hard reset and SCSI bus reset
170 versus sending a bus device reset message to the individual target device
171 based on the recommendation of the SCSI subsystem. Error recovery strategies
172 are selectable through driver options individually for each target device,
173 and also include sending a bus device reset to the specific target device
174 associated with the command being reset, as well as suppressing error
175 recovery entirely to avoid perturbing an improperly functioning device. If
176 the bus device reset error recovery strategy is selected and sending a bus
177 device reset does not restore correct operation, the next command that is
178 reset will force a full host adapter hard reset and SCSI bus reset. SCSI bus
179 resets caused by other devices and detected by the host adapter are also
180 handled by issuing a soft reset to the host adapter and re-initialization.
181 Finally, if tagged queuing is active and more than one command reset occurs
182 in a 10 minute interval, or if a command reset occurs within the first 10
183 minutes of operation, then tagged queuing will be disabled for that target
184 device. These error recovery options improve overall system robustness by
185 preventing individual errant devices from causing the system as a whole to
186 lock up or crash, and thereby allowing a clean shutdown and restart after the
187 offending component is removed.
189 PCI Configuration Support
190 -------------------------
192 On PCI systems running kernels compiled with PCI BIOS support enabled, this
193 driver will interrogate the PCI configuration space and use the I/O port
194 addresses assigned by the system BIOS, rather than the ISA compatible I/O
195 port addresses. The ISA compatible I/O port address is then disabled by the
196 driver. On PCI systems it is also recommended that the AutoSCSI utility be
197 used to disable the ISA compatible I/O port entirely as it is not necessary.
198 The ISA compatible I/O port is disabled by default on the BT-948/958/958D.
200 /proc File System Support
201 -------------------------
203 Copies of the host adapter configuration information together with updated
204 data transfer and error recovery statistics are available through the
205 /proc/scsi/BusLogic/<N> interface.
207 Shared Interrupts Support
208 -------------------------
210 On systems that support shared interrupts, any number of BusLogic Host
211 Adapters may share the same interrupt request channel.
214 Supported Host Adapters
215 =======================
217 The following list comprises the supported BusLogic SCSI Host Adapters as of
218 the date of this document. It is recommended that anyone purchasing a BusLogic
219 Host Adapter not in the following table contact the author beforehand to verify
220 that it is or will be supported.
222 FlashPoint Series PCI Host Adapters:
224 ======================= =============================================
225 FlashPoint LT (BT-930) Ultra SCSI-3
226 FlashPoint LT (BT-930R) Ultra SCSI-3 with RAIDPlus
227 FlashPoint LT (BT-920) Ultra SCSI-3 (BT-930 without BIOS)
228 FlashPoint DL (BT-932) Dual Channel Ultra SCSI-3
229 FlashPoint DL (BT-932R) Dual Channel Ultra SCSI-3 with RAIDPlus
230 FlashPoint LW (BT-950) Wide Ultra SCSI-3
231 FlashPoint LW (BT-950R) Wide Ultra SCSI-3 with RAIDPlus
232 FlashPoint DW (BT-952) Dual Channel Wide Ultra SCSI-3
233 FlashPoint DW (BT-952R) Dual Channel Wide Ultra SCSI-3 with RAIDPlus
234 ======================= =============================================
236 MultiMaster "W" Series Host Adapters:
238 ======= === ==============================
239 BT-948 PCI Ultra SCSI-3
240 BT-958 PCI Wide Ultra SCSI-3
241 BT-958D PCI Wide Differential Ultra SCSI-3
242 ======= === ==============================
244 MultiMaster "C" Series Host Adapters:
246 ======== ==== ==============================
247 BT-946C PCI Fast SCSI-2
248 BT-956C PCI Wide Fast SCSI-2
249 BT-956CD PCI Wide Differential Fast SCSI-2
250 BT-445C VLB Fast SCSI-2
251 BT-747C EISA Fast SCSI-2
252 BT-757C EISA Wide Fast SCSI-2
253 BT-757CD EISA Wide Differential Fast SCSI-2
254 ======== ==== ==============================
256 MultiMaster "S" Series Host Adapters:
258 ======= ==== ==============================
259 BT-445S VLB Fast SCSI-2
260 BT-747S EISA Fast SCSI-2
261 BT-747D EISA Differential Fast SCSI-2
262 BT-757S EISA Wide Fast SCSI-2
263 BT-757D EISA Wide Differential Fast SCSI-2
264 BT-742A EISA SCSI-2 (742A revision H)
265 ======= ==== ==============================
267 MultiMaster "A" Series Host Adapters:
269 ======= ==== ==============================
270 BT-742A EISA SCSI-2 (742A revisions A - G)
271 ======= ==== ==============================
273 AMI FastDisk Host Adapters that are true BusLogic MultiMaster clones are also
274 supported by this driver.
276 BusLogic SCSI Host Adapters are available packaged both as bare boards and as
277 retail kits. The BT- model numbers above refer to the bare board packaging.
278 The retail kit model numbers are found by replacing BT- with KT- in the above
279 list. The retail kit includes the bare board and manual as well as cabling and
280 driver media and documentation that are not provided with bare boards.
283 FlashPoint Installation Notes
284 =============================
289 FlashPoint Host Adapters now include RAIDPlus, Mylex's bootable software
290 RAID. RAIDPlus is not supported on Linux, and there are no plans to support
291 it. The MD driver in Linux 2.0 provides for concatenation (LINEAR) and
292 striping (RAID-0), and support for mirroring (RAID-1), fixed parity (RAID-4),
293 and distributed parity (RAID-5) is available separately. The built-in Linux
294 RAID support is generally more flexible and is expected to perform better
295 than RAIDPlus, so there is little impetus to include RAIDPlus support in the
298 Enabling UltraSCSI Transfers
299 ----------------------------
301 FlashPoint Host Adapters ship with their configuration set to "Factory
302 Default" settings that are conservative and do not allow for UltraSCSI speed
303 to be negotiated. This results in fewer problems when these host adapters
304 are installed in systems with cabling or termination that is not sufficient
305 for UltraSCSI operation, or where existing SCSI devices do not properly
306 respond to synchronous transfer negotiation for UltraSCSI speed. AutoSCSI
307 may be used to load "Optimum Performance" settings which allow UltraSCSI
308 speed to be negotiated with all devices, or UltraSCSI speed can be enabled on
309 an individual basis. It is recommended that SCAM be manually disabled after
310 the "Optimum Performance" settings are loaded.
313 BT-948/958/958D Installation Notes
314 ==================================
316 The BT-948/958/958D PCI Ultra SCSI Host Adapters have some features which may
317 require attention in some circumstances when installing Linux.
319 PCI I/O Port Assignments
320 ------------------------
322 When configured to factory default settings, the BT-948/958/958D will only
323 recognize the PCI I/O port assignments made by the motherboard's PCI BIOS.
324 The BT-948/958/958D will not respond to any of the ISA compatible I/O ports
325 that previous BusLogic SCSI Host Adapters respond to. This driver supports
326 the PCI I/O port assignments, so this is the preferred configuration.
327 However, if the obsolete BusLogic driver must be used for any reason, such as
328 a Linux distribution that does not yet use this driver in its boot kernel,
329 BusLogic has provided an AutoSCSI configuration option to enable a legacy ISA
332 To enable this backward compatibility option, invoke the AutoSCSI utility via
333 Ctrl-B at system startup and select "Adapter Configuration", "View/Modify
334 Configuration", and then change the "ISA Compatible Port" setting from
335 "Disable" to "Primary" or "Alternate". Once this driver has been installed,
336 the "ISA Compatible Port" option should be set back to "Disable" to avoid
337 possible future I/O port conflicts. The older BT-946C/956C/956CD also have
338 this configuration option, but the factory default setting is "Primary".
340 PCI Slot Scanning Order
341 -----------------------
343 In systems with multiple BusLogic PCI Host Adapters, the order in which the
344 PCI slots are scanned may appear reversed with the BT-948/958/958D as
345 compared to the BT-946C/956C/956CD. For booting from a SCSI disk to work
346 correctly, it is necessary that the host adapter's BIOS and the kernel agree
347 on which disk is the boot device, which requires that they recognize the PCI
348 host adapters in the same order. The motherboard's PCI BIOS provides a
349 standard way of enumerating the PCI host adapters, which is used by the Linux
350 kernel. Some PCI BIOS implementations enumerate the PCI slots in order of
351 increasing bus number and device number, while others do so in the opposite
354 Unfortunately, Microsoft decided that Windows 95 would always enumerate the
355 PCI slots in order of increasing bus number and device number regardless of
356 the PCI BIOS enumeration, and requires that their scheme be supported by the
357 host adapter's BIOS to receive Windows 95 certification. Therefore, the
358 factory default settings of the BT-948/958/958D enumerate the host adapters
359 by increasing bus number and device number. To disable this feature, invoke
360 the AutoSCSI utility via Ctrl-B at system startup and select "Adapter
361 Configuration", "View/Modify Configuration", press Ctrl-F10, and then change
362 the "Use Bus And Device # For PCI Scanning Seq." option to OFF.
364 This driver will interrogate the setting of the PCI Scanning Sequence option
365 so as to recognize the host adapters in the same order as they are enumerated
366 by the host adapter's BIOS.
368 Enabling UltraSCSI Transfers
369 ----------------------------
371 The BT-948/958/958D ship with their configuration set to "Factory Default"
372 settings that are conservative and do not allow for UltraSCSI speed to be
373 negotiated. This results in fewer problems when these host adapters are
374 installed in systems with cabling or termination that is not sufficient for
375 UltraSCSI operation, or where existing SCSI devices do not properly respond
376 to synchronous transfer negotiation for UltraSCSI speed. AutoSCSI may be
377 used to load "Optimum Performance" settings which allow UltraSCSI speed to be
378 negotiated with all devices, or UltraSCSI speed can be enabled on an
379 individual basis. It is recommended that SCAM be manually disabled after the
380 "Optimum Performance" settings are loaded.
386 BusLogic Driver Options may be specified either via the Linux Kernel Command
387 Line or via the Loadable Kernel Module Installation Facility. Driver Options
388 for multiple host adapters may be specified either by separating the option
389 strings by a semicolon, or by specifying multiple "BusLogic=" strings on the
390 command line. Individual option specifications for a single host adapter are
391 separated by commas. The Probing and Debugging Options apply to all host
392 adapters whereas the remaining options apply individually only to the
393 selected host adapter.
395 The BusLogic Driver Probing Options comprise the following:
399 The "NoProbe" option disables all probing and therefore no BusLogic Host
400 Adapters will be detected.
404 The "NoProbePCI" options disables the interrogation of PCI Configuration
405 Space and therefore only ISA Multimaster Host Adapters will be detected, as
406 well as PCI Multimaster Host Adapters that have their ISA Compatible I/O
407 Port set to "Primary" or "Alternate".
411 The "NoSortPCI" option forces PCI MultiMaster Host Adapters to be
412 enumerated in the order provided by the PCI BIOS, ignoring any setting of
413 the AutoSCSI "Use Bus And Device # For PCI Scanning Seq." option.
417 The "MultiMasterFirst" option forces MultiMaster Host Adapters to be probed
418 before FlashPoint Host Adapters. By default, if both FlashPoint and PCI
419 MultiMaster Host Adapters are present, this driver will probe for
420 FlashPoint Host Adapters first unless the BIOS primary disk is controlled
421 by the first PCI MultiMaster Host Adapter, in which case MultiMaster Host
422 Adapters will be probed first.
426 The "FlashPointFirst" option forces FlashPoint Host Adapters to be probed
427 before MultiMaster Host Adapters.
429 The BusLogic Driver Tagged Queuing Options allow for explicitly specifying
430 the Queue Depth and whether Tagged Queuing is permitted for each Target
431 Device (assuming that the Target Device supports Tagged Queuing). The Queue
432 Depth is the number of SCSI Commands that are allowed to be concurrently
433 presented for execution (either to the Host Adapter or Target Device). Note
434 that explicitly enabling Tagged Queuing may lead to problems; the option to
435 enable or disable Tagged Queuing is provided primarily to allow disabling
436 Tagged Queuing on Target Devices that do not implement it correctly. The
437 following options are available:
441 The "QueueDepth:" or QD:" option specifies the Queue Depth to use for all
442 Target Devices that support Tagged Queuing, as well as the maximum Queue
443 Depth for devices that do not support Tagged Queuing. If no Queue Depth
444 option is provided, the Queue Depth will be determined automatically based
445 on the Host Adapter's Total Queue Depth and the number, type, speed, and
446 capabilities of the detected Target Devices. Target Devices that
447 do not support Tagged Queuing always have their Queue Depth set to
448 BusLogic_UntaggedQueueDepth or BusLogic_UntaggedQueueDepthBB, unless a
449 lower Queue Depth option is provided. A Queue Depth of 1 automatically
450 disables Tagged Queuing.
452 QueueDepth:[<integer>,<integer>...]
454 The "QueueDepth:[...]" or "QD:[...]" option specifies the Queue Depth
455 individually for each Target Device. If an <integer> is omitted, the
456 associated Target Device will have its Queue Depth selected automatically.
458 TaggedQueuing:Default
460 The "TaggedQueuing:Default" or "TQ:Default" option permits Tagged Queuing
461 based on the firmware version of the BusLogic Host Adapter and based on
462 whether the Queue Depth allows queuing multiple commands.
466 The "TaggedQueuing:Enable" or "TQ:Enable" option enables Tagged Queuing for
467 all Target Devices on this Host Adapter, overriding any limitation that
468 would otherwise be imposed based on the Host Adapter firmware version.
470 TaggedQueuing:Disable
472 The "TaggedQueuing:Disable" or "TQ:Disable" option disables Tagged Queuing
473 for all Target Devices on this Host Adapter.
475 TaggedQueuing:<Target-Spec>
477 The "TaggedQueuing:<Target-Spec>" or "TQ:<Target-Spec>" option controls
478 Tagged Queuing individually for each Target Device. <Target-Spec> is a
479 sequence of "Y", "N", and "X" characters. "Y" enables Tagged Queuing, "N"
480 disables Tagged Queuing, and "X" accepts the default based on the firmware
481 version. The first character refers to Target Device 0, the second to
482 Target Device 1, and so on; if the sequence of "Y", "N", and "X" characters
483 does not cover all the Target Devices, unspecified characters are assumed
486 The BusLogic Driver Miscellaneous Options comprise the following:
488 BusSettleTime:<seconds>
490 The "BusSettleTime:" or "BST:" option specifies the Bus Settle Time in
491 seconds. The Bus Settle Time is the amount of time to wait between a Host
492 Adapter Hard Reset which initiates a SCSI Bus Reset and issuing any SCSI
493 Commands. If unspecified, it defaults to BusLogic_DefaultBusSettleTime.
497 The "InhibitTargetInquiry" option inhibits the execution of an Inquire
498 Target Devices or Inquire Installed Devices command on MultiMaster Host
499 Adapters. This may be necessary with some older Target Devices that do not
500 respond correctly when Logical Units above 0 are addressed.
502 The BusLogic Driver Debugging Options comprise the following:
506 The "TraceProbe" option enables tracing of Host Adapter Probing.
510 The "TraceHardwareReset" option enables tracing of Host Adapter Hardware
515 The "TraceConfiguration" option enables tracing of Host Adapter
520 The "TraceErrors" option enables tracing of SCSI Commands that return an
521 error from the Target Device. The CDB and Sense Data will be printed for
522 each SCSI Command that fails.
526 The "Debug" option enables all debugging options.
528 The following examples demonstrate setting the Queue Depth for Target Devices
529 1 and 2 on the first host adapter to 7 and 15, the Queue Depth for all Target
530 Devices on the second host adapter to 31, and the Bus Settle Time on the
531 second host adapter to 30 seconds.
533 Linux Kernel Command Line::
535 linux BusLogic=QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30
537 LILO Linux Boot Loader (in /etc/lilo.conf)::
539 append = "BusLogic=QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30"
541 INSMOD Loadable Kernel Module Installation Facility::
544 'BusLogic="QueueDepth:[,7,15];QueueDepth:31,BusSettleTime:30"'
549 Module Utilities 2.1.71 or later is required for correct parsing
550 of driver options containing commas.
556 This distribution was prepared for Linux kernel version 2.0.35, but should be
557 compatible with 2.0.4 or any later 2.0 series kernel.
559 To install the new BusLogic SCSI driver, you may use the following commands,
560 replacing "/usr/src" with wherever you keep your Linux kernel source tree::
563 tar -xvzf BusLogic-2.0.15.tar.gz
564 mv README.* LICENSE.* BusLogic.[ch] FlashPoint.c linux/drivers/scsi
565 patch -p0 < BusLogic.patch (only for 2.0.33 and below)
570 Then install "arch/x86/boot/zImage" as your standard kernel, run lilo if
571 appropriate, and reboot.
574 BusLogic Announcements Mailing List
575 ===================================
577 The BusLogic Announcements Mailing List provides a forum for informing Linux
578 users of new driver releases and other announcements regarding Linux support
579 for BusLogic SCSI Host Adapters. To join the mailing list, send a message to
580 "buslogic-announce-request@dandelion.com" with the line "subscribe" in the
projects / linux-2.6-microblaze.git / blob