Copyright (c) 1995, 1996, 1997, 1998, 2000
Justin T. Gibbs. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
$FreeBSD: src/share/man/man4/ahc.4,v 1.22 2000/02/14 16:40:58 gibbs Exp $
.Dd February 13, 2000 .Dt AHC 4 .Os .Os FreeBSD
.Sh NAME .Nm ahc .Nd Adaptec VL/EISA/PCI/CardBus SCSI host adapter driver .Sh SYNOPSIS For one or more VL/EISA cards: .Cd device eisa .Cd device ahc \} \{For VL cards: .Cd ahc0 at isa? port ? irq ?
p For EISA cards: .Cd ahc* at eisa? slot ?\}
p For one or more PCI cards: .Cd device pci .Cd device ahc \} \{For PCI cards: .Cd ahc* at pci? dev ? function ?
p For CardBus cards: .Cd ahc* at cardbus? dev ? function ?\}
p To allow PCI adapters to use memory mapped I/O if enabled: .Cd options AHC_ALLOW_MEMIO
p To configure one or more controllers to assume the target role: .Cd options AHC_TMODE_ENABLE <bitmask of units>
p \} For one or more SCSI busses: .Cd device scbus0 at ahc0 \} \{For .Tn SCSI busses: .Cd scsibus* at ahc?\} .Sh DESCRIPTION This driver provides access to the .Tn SCSI bus(es) connected to Adaptec .Tn AIC7770, .Tn AIC7850, .Tn AIC7860, .Tn AIC7870, .Tn AIC7880, .Tn AIC7890, .Tn AIC7891, .Tn AIC7892, .Tn AIC7895, .Tn AIC7896, .Tn AIC7897 and .Tn AIC7899 host adapter chips. These chips are found on many motherboards as well as the following Adaptec SCSI controller cards: .Tn 274X(W), .Tn 274X(T), .Tn 284X, .Tn 2910, .Tn 2915, .Tn 2920, .Tn 2930C, .Tn 2930U2, .Tn 2940, .Tn 2940U, .Tn 2940AU, .Tn 2940UW, .Tn 2940UW Dual, .Tn 2940UW Pro, .Tn 2940U2W, .Tn 2940U2B, .Tn 2950U2W, .Tn 2950U2B, .Tn 19160B, .Tn 29160B, .Tn 29160N, .Tn 3940, .Tn 3940U, .Tn 3940AU, .Tn 3940UW, .Tn 3940AUW, .Tn 3940U2W, .Tn 3950U2, .Tn 3960, .Tn 39160, .Tn 3985, and .Tn 4944UW. \} \{The .Nm device driver supports .Tn SCSI controllers based on .Tn Adaptec .Tn AIC77xx and .Tn AIC78xx .Tn SCSI host adapter chips found on many motherboards as well as .Tn Adaptec .Tn SCSI controller cards.\}
p Driver features include support for twin and wide busses, fast, ultra or ultra2 synchronous transfers depending on controller type, tagged queuing, SCB paging, and target mode. \} \{ tagged queuing and SCB paging.\}
p Memory mapped I/O can be enabled for PCI devices with the .Dq Dv AHC_ALLOW_MEMIO configuration option. Memory mapped I/O is more efficient than the alternative, programmed I/O. Most PCI BIOSes will map devices so that either technique for communicating with the card is available. In some cases, usually when the PCI device is sitting behind a PCI->PCI bridge, the BIOS may fail to properly initialize the chip for memory mapped I/O. The typical symptom of this problem is a system hang if memory mapped I/O is attempted. Most modern motherboards perform the initialization correctly and work fine with this option enabled.
p Individual controllers may be configured to operate in the target role through the .Dq Dv AHC_TMODE_ENABLE configuration option. The value assigned to this option should be a bitmap of all units where target mode is desired. For example, a value of 0x25, would enable target mode on units 0, 2, and 5.
p \} Per target configuration performed in the .Tn SCSI-Select menu, accessible at boot in .No non- Ns Tn EISA models, or through an .Tn EISA configuration utility for .Tn EISA models, is honored by this driver. This includes synchronous/asynchronous transfers, maximum synchronous negotiation rate, wide transfers, disconnection, the host adapter's SCSI ID, and, in the case of .Tn EISA Twin Channel controllers, the primary channel selection. For systems that store non-volatile settings in a system specific manner rather than a serial eeprom directly connected to the aic7xxx controller, the .Tn BIOS must be enabled for the driver to access this information. This restriction applies to all .Tn EISA and many motherboard configurations.
p Note that I/O addresses are determined automatically by the probe routines, but care should be taken when using a 284x
q Tn VESA No local bus controller in an .Tn EISA system. The jumpers setting the I/O area for the 284x should match the .Tn EISA slot into which the card is inserted to prevent conflicts with other .Tn EISA cards.
p Performance and feature sets vary throughout the aic7xxx product line. The following table provides a comparison of the different chips supported by the .Nm driver. Note that wide and twin channel features, although always supported by a particular chip, may be disabled in a particular motherboard or card design.
p d -filled -offset indent l -column "aic7770 " "10 " "EISA/VL " "10MHz " "16bit " "SCBs " Features .Em "Chip MIPS Bus MaxSync MaxWidth SCBs Features" aic7770 10 EISA/VL 10MHz 16Bit 4 1 aic7850 10 PCI/32 10MHz 8Bit 3 aic7860 10 PCI/32 20MHz 8Bit 3 aic7870 10 PCI/32 10MHz 16Bit 16 aic7880 10 PCI/32 20MHz 16Bit 16 aic7890 20 PCI/32 40MHz 16Bit 16 3 4 5 6 7 8 aic7891 20 PCI/64 40MHz 16Bit 16 3 4 5 6 7 8 aic7892 20 PCI/64 80MHz 16Bit 16 3 4 5 6 7 8 aic7895 15 PCI/32 20MHz 16Bit 16 2 3 4 5 aic7895C 15 PCI/32 20MHz 16Bit 16 2 3 4 5 8 aic7896 20 PCI/32 40MHz 16Bit 16 2 3 4 5 6 7 8 aic7897 20 PCI/64 40MHz 16Bit 16 2 3 4 5 6 7 8 aic7899 20 PCI/64 80MHz 16Bit 16 2 3 4 5 6 7 8 .El l -enum -compact t Multiplexed Twin Channel Device - One controller servicing two busses. t Multi-function Twin Channel Device - Two controllers on one chip. t Command Channel Secondary DMA Engine - Allows scatter gather list and SCB prefetch. t 64 Byte SCB Support - SCSI CDB is embedded in the SCB to eliminate an extra DMA. t Block Move Instruction Support - Doubles the speed of certain sequencer operations. t .Sq Bayonet style Scatter Gather Engine - Improves S/G prefetch performance. t Queuing Registers - Allows queuing of new transactions without pausing the sequencer. t Multiple Target IDs - Allows the controller to respond to selection as a target on multiple SCSI IDs. .El .Ed
p .Sh HARDWARE Supported .Tn SCSI controllers include:
p l -item -offset indent t .Tn Adaptec AHA-2742W EISA Fast Wide SCSI adapter t .Tn Adaptec AHA-274xAT EISA dual channel Fast SCSI adapter t .Tn Adaptec AHA-284x VL Fast SCSI adapter t .Tn Adaptec AHA-2910 PCI Fast SCSI adapter (no SCSI BIOS) t .Tn Adaptec AHA-2915 PCI Fast SCSI adapter (no SCSI BIOS) t .Tn Adaptec AHA-2920 PCI Fast SCSI adapter t .Tn Adaptec AHA-2930C PCI Ultra SCSI adapter t .Tn Adaptec AHA-2930U2 PCI Ultra2 Wide LVD SCSI adapter t .Tn Adaptec AHA-2940 PCI Fast SCSI adapter t .Tn Adaptec AHA-2940U PCI Ultra SCSI adapter t .Tn Adaptec AHA-2940AU PCI Ultra SCSI adapter t .Tn Adaptec AHA-2940UW PCI Ultra Wide SCSI adapter t .Tn Adaptec AHA-2940UW Dual PCI dual channel Ultra Wide SCSI adapter t .Tn Adaptec AHA-2940UW Pro PCI Ultra Wide SCSI adapter t .Tn Adaptec AHA-2940U2W PCI Ultra2 Wide LVD SCSI adapter t .Tn Adaptec AHA-2940U2B PCI Ultra2 Wide LVD SCSI adapter t .Tn Adaptec AHA-2944W PCI Fast Wide Differential SCSI adapter t .Tn Adaptec AHA-2944UW PCI Ultra Wide Differential SCSI adapter t .Tn Adaptec AHA-2950U2W t .Tn Adaptec AHA-2950U2B 64bit PCI Ultra2 Wide LVD SCSI adapter t .Tn Adaptec AHA-19160B PCI Ultra160 Wide LVD SCSI adapter t .Tn Adaptec AHA-29160N PCI Ultra160 Wide LVD SCSI adapter t .Tn Adaptec AHA-29160B 64bit PCI Ultra160 Wide LVD SCSI adapter t .Tn Adaptec AHA-3940 PCI dual channel Fast SCSI adapter t .Tn Adaptec AHA-3940U PCI dual channel Ultra SCSI adapter t .Tn Adaptec AHA-3940AU PCI dual channel Ultra SCSI adapter t .Tn Adaptec AHA-3940UW PCI dual channel Ultra Wide SCSI adapter t .Tn Adaptec AHA-3940AUW PCI dual channel Ultra Wide SCSI adapter t .Tn Adaptec AHA-3940U2W PCI dual channel Ultra2 Wide LVD SCSI adapter t .Tn Adaptec AHA-3950U2 64bit PCI dual channel Ultra2 Wide LVD SCSI adapter t .Tn Adaptec AHA-3960 64bit PCI dual channel Ultra160 Wide LVD SCSI adapter t .Tn Adaptec AHA-3985 PCI dual channel Fast SCSI RAID adapter t .Tn Adaptec AHA-39160 64bit PCI dual channel Ultra160 Wide LVD SCSI adapter t .Tn Adaptec AHA-4944UW PCI quad channel PCI Ultra Wide Differential SCSI adapter t Other SCSI controllers based on the .Tn Adaptec .Tn AIC7770, .Tn AIC7850, .Tn AIC7860, .Tn AIC7870, .Tn AIC7880, .Tn AIC7890, .Tn AIC7891, .Tn AIC7892, .Tn AIC7895, .Tn AIC7896, .Tn AIC7897 and .Tn AIC7899 .Tn SCSI host adapter chips. .El .Sh SCSI CONTROL BLOCKS (SCBs) Every transaction sent to a device on the SCSI bus is assigned a .Sq SCSI Control Block (SCB). The SCB contains all of the information required by the controller to process a transaction. The chip feature table lists the number of SCBs that can be stored in on-chip memory. All chips with model numbers greater than or equal to 7870 allow for the on chip SCB space to be augmented with external SRAM up to a maximum of 255 SCBs. Very few Adaptec controller configurations have external SRAM.
p If external SRAM is not available, SCBs are a limited resource. Using the SCBs in a straight forward manner would only allow the driver to handle as many concurrent transactions as there are physical SCBs. To fully utilize the SCSI bus and the devices on it, requires much more concurrency. The solution to this problem is .Em SCB Paging , a concept similar to memory paging. SCB paging takes advantage of the fact that devices usually disconnect from the SCSI bus for long periods of time without talking to the controller. The SCBs for disconnected transactions are only of use to the controller when the transfer is resumed. When the host queues another transaction for the controller to execute, the controller firmware will use a free SCB if one is available. Otherwise, the state of the most recently disconnected (and therefor most likely to stay disconnected) SCB is saved, via dma, to host memory, and the local SCB reused to start the new transaction. This allows the controller to queue up to 255 transactions regardless of the amount of SCB space. Since the local SCB space serves as a cache for disconnected transactions, the more SCB space available, the less host bus traffic consumed saving and restoring SCB data. .Sh BUGS Some .Tn Quantum drives (at least the Empire 2100 and 1080s) will not run on an .Tn AIC7870 Rev B in synchronous mode at 10MHz. Controllers with this problem have a 42 MHz clock crystal on them and run slightly above 10MHz. This confuses the drive and hangs the bus. Setting a maximum synchronous negotiation rate of 8MHz in the .Tn SCSI-Select utility will allow normal operation.
p Double Transition clocking is not yet supported for Ultra160 controllers. This limits these controllers to 40MHz or 80MB/s.
p Although the Ultra2 and Ultra160 products have sufficient instruction ram space to support both the initiator and target roles concurrently, this configuration is disabled in favor of allowing the target role to respond on multiple target ids. A method for configuring dual role mode should be provided.
p Tagged Queuing is not supported in target mode.
p Reselection in target mode fails to function correctly on all high voltage differential boards as shipped by Adaptec. Information on how to modify HVD board to work correctly in target mode is available from Adaptec. \} \{Target mode is not supported on .Nx version of this driver.\} .Sh SEE ALSO .Xr intro 4 , .Xr aha 4 , .Xr ahb 4 , .Xr cd 4 , .Xr da 4 , .Xr sa 4 , .Xr scsi 4 \} \{ .Xr cd 4 , .Xr ch 4 , .Xr scsi 4 , .Xr sd 4 , .Xr st 4\} .Sh AUTHORS The .Nm driver, the .Tn AIC7xxx sequencer-code assembler, and the firmware running on the aic7xxx chips was written by .An Justin T. Gibbs . .Nx porting is done by Stefan Grefen, Charles M. Hannum, Michael Graff, Jason R. Thorpe, Pete Bentley, Frank van der Linden and Noriyuki Soda. .Sh HISTORY The .Nm driver appeared in .Fx 2.0 and .Nx 1.1 .