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Commit d5b4bb4d authored by Linus Torvalds's avatar Linus Torvalds
Browse files
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 a5e371f6: "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
parents c80ddb52 bb8187d3
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@@ -218,8 +218,6 @@ m68k/
	- directory with info about Linux on Motorola 68k architecture.
	- directory with info about Linux on Motorola 68k architecture.
magic-number.txt
magic-number.txt
	- list of magic numbers used to mark/protect kernel data structures.
	- 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
md.txt
	- info on boot arguments for the multiple devices driver.
	- info on boot arguments for the multiple devices driver.
memory-barriers.txt
memory-barriers.txt
+1 −1
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@@ -6,7 +6,7 @@
# To add a new book the only step required is to add the book to the
# To add a new book the only step required is to add the book to the
# list of DOCBOOKS.
# 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 \
	    kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
	    writing_usb_driver.xml networking.xml \
	    writing_usb_driver.xml networking.xml \
	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
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Original line number Original line Diff line number Diff line
@@ -212,19 +212,6 @@ X!Edrivers/pci/hotplug.c
     <sect1><title>PCI Hotplug Support Library</title>
     <sect1><title>PCI Hotplug Support Library</title>
!Edrivers/pci/hotplug/pci_hotplug_core.c
!Edrivers/pci/hotplug/pci_hotplug_core.c
     </sect1>
     </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>


  <chapter id="firmware">
  <chapter id="firmware">
+0 −107
Original line number Original line Diff line number Diff line
<?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>
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@@ -847,13 +847,7 @@ Your cooperation is appreciated.
		    ...
		    ...
		 31 = /dev/tap15	16th Ethertap device
		 31 = /dev/tap15	16th Ethertap device


 36 block	MCA ESDI hard disk
 36 block	OBSOLETE (was 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).


 37 char	IDE tape
 37 char	IDE tape
		  0 = /dev/ht0		First IDE tape
		  0 = /dev/ht0		First IDE tape
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