diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/DocBook/Makefile | 2 | ||||
| -rw-r--r-- | Documentation/DocBook/kernel-api.tmpl | 13 | ||||
| -rw-r--r-- | Documentation/DocBook/mcabook.tmpl | 107 | ||||
| -rw-r--r-- | Documentation/devices.txt | 8 | ||||
| -rw-r--r-- | Documentation/eisa.txt | 2 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 1 | ||||
| -rw-r--r-- | Documentation/mca.txt | 313 | ||||
| -rw-r--r-- | Documentation/scsi/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/scsi/ibmmca.txt | 1402 | ||||
| -rw-r--r-- | Documentation/scsi/scsi-parameters.txt | 6 | ||||
| -rw-r--r-- | Documentation/scsi/scsi_mid_low_api.txt | 2 | ||||
| -rw-r--r-- | Documentation/serial/stallion.txt | 22 |
13 files changed, 15 insertions, 1867 deletions
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX index 2214f123a97..49c051380da 100644 --- a/Documentation/00-INDEX +++ b/Documentation/00-INDEX @@ -218,8 +218,6 @@ m68k/ - directory with info about Linux on Motorola 68k architecture. magic-number.txt - list of magic numbers used to mark/protect kernel data structures. -mca.txt - - info on supporting Micro Channel Architecture (e.g. PS/2) systems. md.txt - info on boot arguments for the multiple devices driver. memory-barriers.txt diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index 66725a3d30d..bc3d9f8c0a9 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -6,7 +6,7 @@ # To add a new book the only step required is to add the book to the # list of DOCBOOKS. -DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \ +DOCBOOKS := z8530book.xml device-drivers.xml \ kernel-hacking.xml kernel-locking.xml deviceiobook.xml \ writing_usb_driver.xml networking.xml \ kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \ diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index 7160652a873..00687ee9d36 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -212,19 +212,6 @@ X!Edrivers/pci/hotplug.c <sect1><title>PCI Hotplug Support Library</title> !Edrivers/pci/hotplug/pci_hotplug_core.c </sect1> - <sect1><title>MCA Architecture</title> - <sect2><title>MCA Device Functions</title> - <para> - Refer to the file arch/x86/kernel/mca_32.c for more information. - </para> -<!-- FIXME: Removed for now since no structured comments in source -X!Earch/x86/kernel/mca_32.c ---> - </sect2> - <sect2><title>MCA Bus DMA</title> -!Iarch/x86/include/asm/mca_dma.h - </sect2> - </sect1> </chapter> <chapter id="firmware"> diff --git a/Documentation/DocBook/mcabook.tmpl b/Documentation/DocBook/mcabook.tmpl deleted file mode 100644 index 467ccac6ec5..00000000000 --- a/Documentation/DocBook/mcabook.tmpl +++ /dev/null @@ -1,107 +0,0 @@ -<?xml version="1.0" encoding="UTF-8"?> -<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" - "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> - -<book id="MCAGuide"> - <bookinfo> - <title>MCA Driver Programming Interface</title> - - <authorgroup> - <author> - <firstname>Alan</firstname> - <surname>Cox</surname> - <affiliation> - <address> - <email>alan@lxorguk.ukuu.org.uk</email> - </address> - </affiliation> - </author> - <author> - <firstname>David</firstname> - <surname>Weinehall</surname> - </author> - <author> - <firstname>Chris</firstname> - <surname>Beauregard</surname> - </author> - </authorgroup> - - <copyright> - <year>2000</year> - <holder>Alan Cox</holder> - <holder>David Weinehall</holder> - <holder>Chris Beauregard</holder> - </copyright> - - <legalnotice> - <para> - This documentation is free software; you can redistribute - it and/or modify it under the terms of the GNU General Public - License as published by the Free Software Foundation; either - version 2 of the License, or (at your option) any later - version. - </para> - - <para> - This program is distributed in the hope that it will be - useful, but WITHOUT ANY WARRANTY; without even the implied - warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. - See the GNU General Public License for more details. - </para> - - <para> - You should have received a copy of the GNU General Public - License along with this program; if not, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, - MA 02111-1307 USA - </para> - - <para> - For more details see the file COPYING in the source - distribution of Linux. - </para> - </legalnotice> - </bookinfo> - -<toc></toc> - - <chapter id="intro"> - <title>Introduction</title> - <para> - The MCA bus functions provide a generalised interface to find MCA - bus cards, to claim them for a driver, and to read and manipulate POS - registers without being aware of the motherboard internals or - certain deep magic specific to onboard devices. - </para> - <para> - The basic interface to the MCA bus devices is the slot. Each slot - is numbered and virtual slot numbers are assigned to the internal - devices. Using a pci_dev as other busses do does not really make - sense in the MCA context as the MCA bus resources require card - specific interpretation. - </para> - <para> - Finally the MCA bus functions provide a parallel set of DMA - functions mimicing the ISA bus DMA functions as closely as possible, - although also supporting the additional DMA functionality on the - MCA bus controllers. - </para> - </chapter> - <chapter id="bugs"> - <title>Known Bugs And Assumptions</title> - <para> - None. - </para> - </chapter> - - <chapter id="pubfunctions"> - <title>Public Functions Provided</title> -!Edrivers/mca/mca-legacy.c - </chapter> - - <chapter id="dmafunctions"> - <title>DMA Functions Provided</title> -!Iarch/x86/include/asm/mca_dma.h - </chapter> - -</book> diff --git a/Documentation/devices.txt b/Documentation/devices.txt index 5941f5136c6..47a154f3029 100644 --- a/Documentation/devices.txt +++ b/Documentation/devices.txt @@ -847,13 +847,7 @@ Your cooperation is appreciated. ... 31 = /dev/tap15 16th Ethertap device - 36 block MCA ESDI hard disk - 0 = /dev/eda First ESDI disk whole disk - 64 = /dev/edb Second ESDI disk whole disk - ... - - Partitions are handled in the same way as IDE disks - (see major number 3). + 36 block OBSOLETE (was MCA ESDI hard disk) 37 char IDE tape 0 = /dev/ht0 First IDE tape diff --git a/Documentation/eisa.txt b/Documentation/eisa.txt index 38cf0c7b559..a55e4910924 100644 --- a/Documentation/eisa.txt +++ b/Documentation/eisa.txt @@ -179,7 +179,7 @@ CONFIG_ALPHA_JENSEN or CONFIG_EISA_VLB_PRIMING are set. Converting an EISA driver to the new API mostly involves *deleting* code (since probing is now in the core EISA code). Unfortunately, most -drivers share their probing routine between ISA, MCA and EISA. Special +drivers share their probing routine between ISA, and EISA. Special care must be taken when ripping out the EISA code, so other busses won't suffer from these surgical strikes... diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8cb10f77c72..5b6e5849222 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -70,7 +70,6 @@ parameter is applicable: M68k M68k architecture is enabled. These options have more detailed description inside of Documentation/m68k/kernel-options.txt. - MCA MCA bus support is enabled. MDA MDA console support is enabled. MIPS MIPS architecture is enabled. MOUSE Appropriate mouse support is enabled. diff --git a/Documentation/mca.txt b/Documentation/mca.txt deleted file mode 100644 index dfd130c2207..00000000000 --- a/Documentation/mca.txt +++ /dev/null @@ -1,313 +0,0 @@ -i386 Micro Channel Architecture Support -======================================= - -MCA support is enabled using the CONFIG_MCA define. A machine with a MCA -bus will have the kernel variable MCA_bus set, assuming the BIOS feature -bits are set properly (see arch/i386/boot/setup.S for information on -how this detection is done). - -Adapter Detection -================= - -The ideal MCA adapter detection is done through the use of the -Programmable Option Select registers. Generic functions for doing -this have been added in include/linux/mca.h and arch/x86/kernel/mca_32.c. -Everything needed to detect adapters and read (and write) configuration -information is there. A number of MCA-specific drivers already use -this. The typical probe code looks like the following: - - #include <linux/mca.h> - - unsigned char pos2, pos3, pos4, pos5; - struct net_device* dev; - int slot; - - if( MCA_bus ) { - slot = mca_find_adapter( ADAPTER_ID, 0 ); - if( slot == MCA_NOTFOUND ) { - return -ENODEV; - } - /* optional - see below */ - mca_set_adapter_name( slot, "adapter name & description" ); - mca_set_adapter_procfn( slot, dev_getinfo, dev ); - - /* read the POS registers. Most devices only use 2 and 3 */ - pos2 = mca_read_stored_pos( slot, 2 ); - pos3 = mca_read_stored_pos( slot, 3 ); - pos4 = mca_read_stored_pos( slot, 4 ); - pos5 = mca_read_stored_pos( slot, 5 ); - } else { - return -ENODEV; - } - - /* extract configuration from pos[2345] and set everything up */ - -Loadable modules should modify this to test that the specified IRQ and -IO ports (plus whatever other stuff) match. See 3c523.c for example -code (actually, smc-mca.c has a slightly more complex example that can -handle a list of adapter ids). - -Keep in mind that devices should never directly access the POS registers -(via inb(), outb(), etc). While it's generally safe, there is a small -potential for blowing up hardware when it's done at the wrong time. -Furthermore, accessing a POS register disables a device temporarily. -This is usually okay during startup, but do _you_ want to rely on it? -During initial configuration, mca_init() reads all the POS registers -into memory. mca_read_stored_pos() accesses that data. mca_read_pos() -and mca_write_pos() are also available for (safer) direct POS access, -but their use is _highly_ discouraged. mca_write_pos() is particularly -dangerous, as it is possible for adapters to be put in inconsistent -states (i.e. sharing IO address, etc) and may result in crashes, toasted -hardware, and blindness. - -User level drivers (such as the AGX X server) can use /proc/mca/pos to -find adapters (see below). - -Some MCA adapters can also be detected via the usual ISA-style device -probing (many SCSI adapters, for example). This sort of thing is highly -discouraged. Perfectly good information is available telling you what's -there, so there's no excuse for messing with random IO ports. However, -we MCA people still appreciate any ISA-style driver that will work with -our hardware. You take what you can get... - -Level-Triggered Interrupts -========================== - -Because MCA uses level-triggered interrupts, a few problems arise with -what might best be described as the ISA mindset and its effects on -drivers. These sorts of problems are expected to become less common as -more people use shared IRQs on PCI machines. - -In general, an interrupt must be acknowledged not only at the ICU (which -is done automagically by the kernel), but at the device level. In -particular, IRQ 0 must be reset after a timer interrupt (now done in -arch/x86/kernel/time.c) or the first timer interrupt hangs the system. -There were also problems with the 1.3.x floppy drivers, but that seems -to have been fixed. - -IRQs are also shareable, and most MCA-specific devices should be coded -with shared IRQs in mind. - -/proc/mca -========= - -/proc/mca is a directory containing various files for adapters and -other stuff. - - /proc/mca/pos Straight listing of POS registers - /proc/mca/slot[1-8] Information on adapter in specific slot - /proc/mca/video Same for integrated video - /proc/mca/scsi Same for integrated SCSI - /proc/mca/machine Machine information - -See Appendix A for a sample. - -Device drivers can easily add their own information function for -specific slots (including integrated ones) via the -mca_set_adapter_procfn() call. Drivers that support this are ESDI, IBM -SCSI, and 3c523. If a device is also a module, make sure that the proc -function is removed in the module cleanup. This will require storing -the slot information in a private structure somewhere. See the 3c523 -driver for details. - -Your typical proc function will look something like this: - - static int - dev_getinfo( char* buf, int slot, void* d ) { - struct net_device* dev = (struct net_device*) d; - int len = 0; - - len += sprintf( buf+len, "Device: %s\n", dev->name ); - len += sprintf( buf+len, "IRQ: %d\n", dev->irq ); - len += sprintf( buf+len, "IO Port: %#lx-%#lx\n", ... ); - ... - - return len; - } - -Some of the standard MCA information will already be printed, so don't -bother repeating it. Don't try putting in more than 3K of information. - -Enable this function with: - mca_set_adapter_procfn( slot, dev_getinfo, dev ); - -Disable it with: - mca_set_adapter_procfn( slot, NULL, NULL ); - -It is also recommended that, even if you don't write a proc function, to -set the name of the adapter (i.e. "PS/2 ESDI Controller") via -mca_set_adapter_name( int slot, char* name ). - -MCA Device Drivers -================== - -Currently, there are a number of MCA-specific device drivers. - -1) PS/2 SCSI - drivers/scsi/ibmmca.c - drivers/scsi/ibmmca.h - The driver for the IBM SCSI subsystem. Includes both integrated - controllers and adapter cards. May require command-line arg - "ibmmcascsi=io_port" to force detection of an adapter. If you have a - machine with a front-panel display (i.e. model 95), you can use - "ibmmcascsi=display" to enable a drive activity indicator. - -2) 3c523 - drivers/net/3c523.c - drivers/net/3c523.h - 3Com 3c523 Etherlink/MC ethernet driver. - -3) SMC Ultra/MCA and IBM Adapter/A - drivers/net/smc-mca.c - drivers/net/smc-mca.h - Driver for the MCA version of the SMC Ultra and various other - OEM'ed and work-alike cards (Elite, Adapter/A, etc). - -4) NE/2 - driver/net/ne2.c - driver/net/ne2.h - The NE/2 is the MCA version of the NE2000. This may not work - with clones that have a different adapter id than the original - NE/2. - -5) Future Domain MCS-600/700, OEM'd IBM Fast SCSI Adapter/A and - Reply Sound Blaster/SCSI (SCSI part) - Better support for these cards than the driver for ISA. - Supports multiple cards with IRQ sharing. - -Also added boot time option of scsi-probe, which can do reordering of -SCSI host adapters. This will direct the kernel on the order which -SCSI adapter should be detected. Example: - scsi-probe=ibmmca,fd_mcs,adaptec1542,buslogic - -The serial drivers were modified to support the extended IO port range -of the typical MCA system (also #ifdef CONFIG_MCA). - -The following devices work with existing drivers: -1) Token-ring -2) Future Domain SCSI (MCS-600, MCS-700, not MCS-350, OEM'ed IBM SCSI) -3) Adaptec 1640 SCSI (using the aha1542 driver) -4) Bustek/Buslogic SCSI (various) -5) Probably all Arcnet cards. -6) Some, possibly all, MCA IDE controllers. -7) 3Com 3c529 (MCA version of 3c509) (patched) - -8) Intel EtherExpressMC (patched version) - You need to have CONFIG_MCA defined to have EtherExpressMC support. -9) Reply Sound Blaster/SCSI (SB part) (patched version) - -Bugs & Other Weirdness -====================== - -NMIs tend to occur with MCA machines because of various hardware -weirdness, bus timeouts, and many other non-critical things. Some basic -code to handle them (inspired by the NetBSD MCA code) has been added to -detect the guilty device, but it's pretty incomplete. If NMIs are a -persistent problem (on some model 70 or 80s, they occur every couple -shell commands), the CONFIG_IGNORE_NMI flag will take care of that. - -Various Pentium machines have had serious problems with the FPU test in -bugs.h. Basically, the machine hangs after the HLT test. This occurs, -as far as we know, on the Pentium-equipped 85s, 95s, and some PC Servers. -The PCI/MCA PC 750s are fine as far as I can tell. The ``mca-pentium'' -boot-prompt flag will disable the FPU bug check if this is a problem -with your machine. - -The model 80 has a raft of problems that are just too weird and unique -to get into here. Some people have no trouble while others have nothing -but problems. I'd suspect some problems are related to the age of the -average 80 and accompanying hardware deterioration, although others -are definitely design problems with the hardware. Among the problems -include SCSI controller problems, ESDI controller problems, and serious -screw-ups in the floppy controller. Oh, and the parallel port is also -pretty flaky. There were about 5 or 6 different model 80 motherboards -produced to fix various obscure problems. As far as I know, it's pretty -much impossible to tell which bugs a particular model 80 has (other than -triggering them, that is). - -Drivers are required for some MCA memory adapters. If you're suddenly -short a few megs of RAM, this might be the reason. The (I think) Enhanced -Memory Adapter commonly found on the model 70 is one. There's a very -alpha driver floating around, but it's pretty ugly (disassembled from -the DOS driver, actually). See the MCA Linux web page (URL below) -for more current memory info. - -The Thinkpad 700 and 720 will work, but various components are either -non-functional, flaky, or we don't know anything about them. The -graphics controller is supposed to be some WD, but we can't get things -working properly. The PCMCIA slots don't seem to work. Ditto for APM. -The serial ports work, but detection seems to be flaky. - -Credits -======= -A whole pile of people have contributed to the MCA code. I'd include -their names here, but I don't have a list handy. Check the MCA Linux -home page (URL below) for a perpetually out-of-date list. - -===================================================================== -MCA Linux Home Page: http://www.dgmicro.com/mca/ - -Christophe Beauregard -chrisb@truespectra.com -cpbeaure@calum.csclub.uwaterloo.ca - -===================================================================== -Appendix A: Sample /proc/mca - -This is from my model 8595. Slot 1 contains the standard IBM SCSI -adapter, slot 3 is an Adaptec AHA-1640, slot 5 is a XGA-1 video adapter, -and slot 7 is the 3c523 Etherlink/MC. - -/proc/mca/machine: -Model Id: 0xf8 -Submodel Id: 0x14 -BIOS Revision: 0x5 - -/proc/mca/pos: -Slot 1: ff 8e f1 fc a0 ff ff ff IBM SCSI Adapter w/Cache -Slot 2: ff ff ff ff ff ff ff ff -Slot 3: 1f 0f 81 3b bf b6 ff ff -Slot 4: ff ff ff ff ff ff ff ff -Slot 5: db 8f 1d 5e fd c0 00 00 -Slot 6: ff ff ff ff ff ff ff ff -Slot 7: 42 60 ff 08 ff ff ff ff 3Com 3c523 Etherlink/MC -Slot 8: ff ff ff ff ff ff ff ff -Video : ff ff ff ff ff ff ff ff -SCSI : ff ff ff ff ff ff ff ff - -/proc/mca/slot1: -Slot: 1 -Adapter Name: IBM SCSI Adapter w/Cache -Id: 8eff -Enabled: Yes -POS: ff 8e f1 fc a0 ff ff ff -Subsystem PUN: 7 -Detected at boot: Yes - -/proc/mca/slot3: -Slot: 3 -Adapter Name: Unknown -Id: 0f1f -Enabled: Yes -POS: 1f 0f 81 3b bf b6 ff ff - -/proc/mca/slot5: -Slot: 5 -Adapter Name: Unknown -Id: 8fdb -Enabled: Yes -POS: db 8f 1d 5e fd c0 00 00 - -/proc/mca/slot7: -Slot: 7 -Adapter Name: 3Com 3c523 Etherlink/MC -Id: 6042 -Enabled: Yes -POS: 42 60 ff 08 ff ff ff ff -Revision: 0xe -IRQ: 9 -IO Address: 0x3300-0x3308 -Memory: 0xd8000-0xdbfff -Transceiver: External -Device: eth0 -Hardware Address: 02 60 8c 45 c4 2a diff --git a/Documentation/scsi/00-INDEX b/Documentation/scsi/00-INDEX index b7dd6502bec..9b0787f965e 100644 --- a/Documentation/scsi/00-INDEX +++ b/Documentation/scsi/00-INDEX @@ -56,8 +56,6 @@ g_NCR5380.txt - info on driver for NCR5380 and NCR53c400 based adapters hptiop.txt - HIGHPOINT ROCKETRAID 3xxx RAID DRIVER -ibmmca.txt - - info on driver for IBM adapters with MCA bus in2000.txt - info on in2000 driver libsas.txt diff --git a/Documentation/scsi/ibmmca.txt b/Documentation/scsi/ibmmca.txt deleted file mode 100644 index ac41a9fcac7..00000000000 --- a/Documentation/scsi/ibmmca.txt +++ /dev/null @@ -1,1402 +0,0 @@ - - -=< The IBM Microchannel SCSI-Subsystem >=- - - for the IBM PS/2 series - - Low Level Software-Driver for Linux - - Copyright (c) 1995 Strom Systems, Inc. under the terms of the GNU - General Public License. Originally written by Martin Kolinek, December 1995. - Officially modified and maintained by Michael Lang since January 1999. - - Version 4.0a - - Last update: January 3, 2001 - - Before you Start - ---------------- - This is the common README.ibmmca file for all driver releases of the - IBM MCA SCSI driver for Linux. Please note, that driver releases 4.0 - or newer do not work with kernel versions older than 2.4.0, while driver - versions older than 4.0 do not work with kernels 2.4.0 or later! If you - try to compile your kernel with the wrong driver source, the - compilation is aborted and you get a corresponding error message. This is - no bug in the driver; it prevents you from using the wrong source code - with the wrong kernel version. - - Authors of this Driver - ---------------------- - - Chris Beauregard (improvement of the SCSI-device mapping by the driver) - - Martin Kolinek (origin, first release of this driver) - - Klaus Kudielka (multiple SCSI-host management/detection, adaption to - Linux Kernel 2.1.x, module support) - - Michael Lang (assigning original pun/lun mapping, dynamical ldn - assignment, rewritten adapter detection, this file, - patches, official driver maintenance and subsequent - debugging, related with the driver) - - Table of Contents - ----------------- - 1 Abstract - 2 Driver Description - 2.1 IBM SCSI-Subsystem Detection - 2.2 Physical Units, Logical Units, and Logical Devices - 2.3 SCSI-Device Recognition and dynamical ldn Assignment - 2.4 SCSI-Device Order - 2.5 Regular SCSI-Command-Processing - 2.6 Abort & Reset Commands - 2.7 Disk Geometry - 2.8 Kernel Boot Option - 2.9 Driver Module Support - 2.10 Multiple Hostadapter Support - 2.11 /proc/scsi-Filesystem Information - 2.12 /proc/mca-Filesystem Information - 2.13 Supported IBM SCSI-Subsystems - 2.14 Linux Kernel Versions - 3 Code History - 4 To do - 5 Users' Manual - 5.1 Commandline Parameters - 5.2 Troubleshooting - 5.3 Bug reports - 5.4 Support WWW-page - 6 References - 7 Credits to - 7.1 People - 7.2 Sponsors & Supporters - 8 Trademarks - 9 Disclaimer - - * * * - - 1 Abstract - ---------- - This README-file describes the IBM SCSI-subsystem low level driver for - Linux. The descriptions which were formerly kept in the source code have - been taken out of this file to simplify the codes readability. The driver - description has been updated, as most of the former description was already - quite outdated. The history of the driver development is also kept inside - here. Multiple historical developments have been summarized to shorten the - text size a bit. At the end of this file you can find a small manual for - this driver and hints to get it running on your machine. - - 2 Driver Description - -------------------- - 2.1 IBM SCSI-Subsystem Detection - -------------------------------- - This is done in the ibmmca_detect() function. It first checks, if the - Microchannel-bus support is enabled, as the IBM SCSI-subsystem needs the - Microchannel. In a next step, a free interrupt is chosen and the main - interrupt handler is connected to it to handle answers of the SCSI- - subsystem(s). If the F/W SCSI-adapter is forced by the BIOS to use IRQ11 - instead of IRQ14, IRQ11 is used for the IBM SCSI-2 F/W adapter. In a - further step it is checked, if the adapter gets detected by force from - the kernel commandline, where the I/O port and the SCSI-subsystem id can - be specified. The next step checks if there is an integrated SCSI-subsystem - installed. This register area is fixed through all IBM PS/2 MCA-machines - and appears as something like a virtual slot 10 of the MCA-bus. On most - PS/2 machines, the POS registers of slot 10 are set to 0xff or 0x00 if not - integrated SCSI-controller is available. But on certain PS/2s, like model - 9595, this slot 10 is used to store other information which at earlier - stage confused the driver and resulted in the detection of some ghost-SCSI. - If POS-register 2 and 3 are not 0x00 and not 0xff, but all other POS - registers are either 0xff or 0x00, there must be an integrated SCSI- - subsystem present and it will be registered as IBM Integrated SCSI- - Subsystem. The next step checks, if there is a slot-adapter installed on - the MCA-bus. To get this, the first two POS-registers, that represent the - adapter ID are checked. If they fit to one of the ids, stored in the - adapter list, a SCSI-subsystem is assumed to be found in a slot and will be - registered. This check is done through all possible MCA-bus slots to allow - more than one SCSI-adapter to be present in the PS/2-system and this is - already the first point of problems. Looking into the technical reference - manual for the IBM PS/2 common interfaces, the POS2 register must have - different interpretation of its single bits to avoid overlapping I/O - regions. While one can assume, that the integrated subsystem has a fix - I/O-address at 0x3540 - 0x3547, further installed IBM SCSI-adapters must - use a different I/O-address. This is expressed by bit 1 to 3 of POS2 - (multiplied by 8 + 0x3540). Bits 2 and 3 are reserved for the integrated - subsystem, but not for the adapters! The following list shows, how the - bits of POS2 and POS3 should be interpreted. - - The POS2-register of all PS/2 models' integrated SCSI-subsystems has the - following interpretation of bits: - Bit 7 - 4 : Chip Revision ID (Release) - Bit 3 - 2 : Reserved - Bit 1 : 8k NVRAM Disabled - Bit 0 : Chip Enable (EN-Signal) - The POS3-register is interpreted as follows (for most IBM SCSI-subsys.): - Bit 7 - 5 : SCSI ID - Bit 4 - 0 : Reserved = 0 - The slot-adapters have different interpretation of these bits. The IBM SCSI - adapter (w/Cache) and the IBM SCSI-2 F/W adapter use the following - interpretation of the POS2 register: - Bit 7 - 4 : ROM Segment Address Select - Bit 3 - 1 : Adapter I/O Address Select (*8+0x3540) - Bit 0 : Adapter Enable (EN-Signal) - and for the POS3 register: - Bit 7 - 5 : SCSI ID - Bit 4 : Fairness Enable (SCSI ID3 f. F/W) - Bit 3 - 0 : Arbitration Level - The most modern product of the series is the IBM SCSI-2 F/W adapter, it - allows dual-bus SCSI and SCSI-wide addressing, which means, PUNs may be - between 0 and 15. Here, Bit 4 is the high-order bit of the 4-bit wide - adapter PUN expression. In short words, this means, that IBM PS/2 machines - can only support 1 single integrated subsystem by default. Additional - slot-adapters get ports assigned by the automatic configuration tool. - - One day I found a patch in ibmmca_detect(), forcing the I/O-address to be - 0x3540 for integrated SCSI-subsystems, there was a remark placed, that on - integrated IBM SCSI-subsystems of model 56, the POS2 register was showing 5. - This means, that really for these models, POS2 has to be interpreted - sticking to the technical reference guide. In this case, the bit 2 (4) is - a reserved bit and may not be interpreted. These differences between the - adapters and the integrated controllers are taken into account by the - detection routine of the driver on from version >3.0g. - - Every time, a SCSI-subsystem is discovered, the ibmmca_register() function - is called. This function checks first, if the requested area for the I/O- - address of this SCSI-subsystem is still available and assigns this I/O- - area to the SCSI-subsystem. There are always 8 sequential I/O-addresses - taken for each individual SCSI-subsystem found, which are: - - Offset Type Permissions - 0 Command Interface Register 1 Read/Write - 1 Command Interface Register 2 Read/Write - 2 Command Interface Register 3 Read/Write - 3 Command Interface Register 4 Read/Write - 4 Attention Register Read/Write - 5 Basic Control Register Read/Write - 6 Interrupt Status Register Read - 7 Basic Status Register Read - - After the I/O-address range is assigned, the host-adapter is assigned - to a local structure which keeps all adapter information needed for the - driver itself and the mid- and higher-level SCSI-drivers. The SCSI pun/lun - and the adapters' ldn tables are initialized and get probed afterwards by - the check_devices() function. If no further adapters are found, - ibmmca_detect() quits. - - 2.2 Physical Units, Logical Units, and Logical Devices - ------------------------------------------------------ - There can be up to 56 devices on the SCSI bus (besides the adapter): - there are up to 7 "physical units" (each identified by physical unit - number or pun, also called the scsi id, this is the number you select - with hardware jumpers), and each physical unit can have up to 8 - "logical units" (each identified by logical unit number, or lun, - between 0 and 7). The IBM SCSI-2 F/W adapter offers this on up to two - busses and provides support for 30 logical devices at the same time, where - in wide-addressing mode you can have 16 puns with 32 luns on each device. - This section describes the handling of devices on non-F/W adapters. - Just imagine, that you can have 16 * 32 = 512 devices on a F/W adapter - which means a lot of possible devices for such a small machine. - - Typically the adapter has pun=7, so puns of other physical units - are between 0 and 6(15). On a wide-adapter a pun higher than 7 is - possible, but is normally not used. Almost all physical units have only - one logical unit, with lun=0. A CD-ROM jukebox would be an example of a - physical unit with more than one logical unit. - - The embedded microprocessor of the IBM SCSI-subsystem hides the complex - two-dimensional (pun,lun) organization from the operating system. - When the machine is powered-up (or rebooted), the embedded microprocessor - checks, on its own, all 56 possible (pun,lun) combinations, and the first - 15 devices found are assigned into a one-dimensional array of so-called - "logical devices", identified by "logical device numbers" or ldn. The last - ldn=15 is reserved for the subsystem itself. Wide adapters may have - to check up to 15 * 8 = 120 pun/lun combinations. - - 2.3 SCSI-Device Recognition and Dynamical ldn Assignment - -------------------------------------------------------- - One consequence of information hiding is that the real (pun,lun) - numbers are also hidden. The two possibilities to get around this problem - are to offer fake pun/lun combinations to the operating system or to - delete the whole mapping of the adapter and to reassign the ldns, using - the immediate assign command of the SCSI-subsystem for probing through - all possible pun/lun combinations. An ldn is a "logical device number" - which is used by IBM SCSI-subsystems to access some valid SCSI-device. - At the beginning of the development of this driver, the following approach - was used: - - First, the driver checked the ldn's (0 to 6) to find out which ldn's - have devices assigned. This was done by the functions check_devices() and - device_exists(). The interrupt handler has a special paragraph of code - (see local_checking_phase_flag) to assist in the checking. Assume, for - example, that three logical devices were found assigned at ldn 0, 1, 2. - These are presented to the upper layer of Linux SCSI driver - as devices with bogus (pun, lun) equal to (0,0), (1,0), (2,0). - On the other hand, if the upper layer issues a command to device - say (4,0), this driver returns DID_NO_CONNECT error. - - In a second step of the driver development, the following improvement has - been applied: The first approach limited the number of devices to 7, far - fewer than the 15 that it could use, then it just mapped ldn -> - (ldn/8,ldn%8) for pun,lun. We ended up with a real mishmash of puns - and luns, but it all seemed to work. - - The latest development, which is implemented from the driver version 3.0 - and later, realizes the device recognition in the following way: - The physical SCSI-devices on the SCSI-bus are probed via immediate_assign- - and device_inquiry-commands, that is all implemented in a completely new - made check_devices() subroutine. This delivers an exact map of the physical - SCSI-world that is now stored in the get_scsi[][]-array. This means, - that the once hidden pun,lun assignment is now known to this driver. - It no longer believes in default-settings of the subsystem and maps all - ldns to existing pun,lun "by foot". This assures full control of the ldn - mapping and allows dynamical remapping of ldns to different pun,lun, if - there are more SCSI-devices installed than ldns available (n>15). The - ldns from 0 to 6 get 'hardwired' by this driver to puns 0 to 7 at lun=0, - excluding the pun of the subsystem. This assures, that at least simple - SCSI-installations have optimum access-speed and are not touched by - dynamical remapping. The ldns 7 to 14 are put to existing devices with - lun>0 or to non-existing devices, in order to satisfy the subsystem, if - there are less than 15 SCSI-devices connected. In the case of more than 15 - devices, the dynamical mapping goes active. If the get_scsi[][] reports a - device to be existent, but it has no ldn assigned, it gets an ldn out of 7 - to 14. The numbers are assigned in cyclic order, therefore it takes 8 - dynamical reassignments on the SCSI-devices until a certain device - loses its ldn again. This assures that dynamical remapping is avoided - during intense I/O between up to 15 SCSI-devices (means pun,lun - combinations). A further advantage of this method is that people who - build their kernel without probing on all luns will get what they expect, - because the driver just won't assign everything with lun>0 when - multiple lun probing is inactive. - - 2.4 SCSI-Device Order - --------------------- - Because of the now correct recognition of physical pun,lun, and - their report to mid-level- and higher-level-drivers, the new reported puns - can be different from the old, faked puns. Therefore, Linux will eventually - change /dev/sdXXX assignments and prompt you for corrupted superblock - repair on boottime. In this case DO NOT PANIC, YOUR DISKS ARE STILL OK!!! - You have to reboot (CTRL-D) with an old kernel and set the /etc/fstab-file - entries right. After that, the system should come up as errorfree as before. - If your boot-partition is not coming up, also edit the /etc/lilo.conf-file - in a Linux session booted on old kernel and run lilo before reboot. Check - lilo.conf anyway to get boot on other partitions with foreign OSes right - a |