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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-23 17:12:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-23 17:12:06 -0700
commitd5b4bb4d103cd601d8009f2d3a7e44586c9ae7cc (patch)
tree0f3b6da2b66fc7a4278764982279c2815c913010 /Documentation
parentc80ddb526331a72c9e9d1480f85f6fd7c74e3d2d (diff)
parentbb8187d35f820671d6dd76700d77a6b55f95e2c5 (diff)
Merge branch 'delete-mca' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
Pull the MCA deletion branch from Paul Gortmaker: "It was good that we could support MCA machines back in the day, but realistically, nobody is using them anymore. They were mostly limited to 386-sx 16MHz CPU and some 486 class machines and never more than 64MB of RAM. Even the enthusiast hobbyist community seems to have dried up close to ten years ago, based on what you can find searching various websites dedicated to the relatively short lived hardware. So lets remove the support relating to CONFIG_MCA. There is no point carrying this forward, wasting cycles doing routine maintenance on it; wasting allyesconfig build time on validating it, wasting I/O on git grep'ping over it, and so on." Let's see if anybody screams. It generally has compiled, and James Bottomley pointed out that there was a MCA extension from NCR that allowed for up to 4GB of memory and PPro-class machines. So in *theory* there may be users out there. But even James (technically listed as a maintainer) doesn't actually have a system, and while Alan Cox claims to have a machine in his cellar that he offered to anybody who wants to take it off his hands, he didn't argue for keeping MCA support either. So we could bring it back. But somebody had better speak up and talk about how they have actually been using said MCA hardware with modern kernels for us to do that. And David already took the patch to delete all the networking driver code (commit a5e371f61ad3: "drivers/net: delete all code/drivers depending on CONFIG_MCA"). * 'delete-mca' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: MCA: delete all remaining traces of microchannel bus support. scsi: delete the MCA specific drivers and driver code serial: delete the MCA specific 8250 support. arm: remove ability to select CONFIG_MCA
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/00-INDEX2
-rw-r--r--Documentation/DocBook/Makefile2
-rw-r--r--Documentation/DocBook/kernel-api.tmpl13
-rw-r--r--Documentation/DocBook/mcabook.tmpl107
-rw-r--r--Documentation/devices.txt8
-rw-r--r--Documentation/eisa.txt2
-rw-r--r--Documentation/kernel-parameters.txt1
-rw-r--r--Documentation/mca.txt313
-rw-r--r--Documentation/scsi/00-INDEX2
-rw-r--r--Documentation/scsi/ibmmca.txt1402
-rw-r--r--Documentation/scsi/scsi-parameters.txt6
-rw-r--r--Documentation/scsi/scsi_mid_low_api.txt2
-rw-r--r--Documentation/serial/stallion.txt22
13 files changed, 15 insertions, 1867 deletions
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 2214f123a976..49c051380daf 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 66725a3d30dc..bc3d9f8c0a90 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 7160652a8736..00687ee9d363 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 467ccac6ec50..000000000000
--- 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 5941f5136c6b..47a154f30290 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 38cf0c7b559f..a55e4910924e 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 8cb10f77c723..5b6e58492229 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 dfd130c2207d..000000000000
--- 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 b7dd6502bec5..9b0787f965e9 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 ac41a9fcac77..000000000000
--- 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.