Documentation: x86: convert mtrr.txt to reST

This converts the plain text documentation to reStructuredText format and
add it to Sphinx TOC tree. No essential content change.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/x86/index.rst

@@ -16,3 +16,4 @@ x86-specific Documentation
    earlyprintk
    zero-page
    tlb
+   mtrr

Documentation/x86/mtrr.txt → Documentation/x86/mtrr.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+=========================================
 MTRR (Memory Type Range Register) control
+=========================================
+
+:Authors: - Richard Gooch <rgooch@atnf.csiro.au> - 3 Jun 1999
+          - Luis R. Rodriguez <mcgrof@do-not-panic.com> - April 9, 2015
 
-Richard Gooch <rgooch@atnf.csiro.au> - 3 Jun 1999
-Luis R. Rodriguez <mcgrof@do-not-panic.com> - April 9, 2015
 
-===============================================================================
 Phasing out MTRR use
+====================
 
 MTRR use is replaced on modern x86 hardware with PAT. Direct MTRR use by
 drivers on Linux is now completely phased out, device drivers should use
@@ -23,10 +28,9 @@ are aligned with platform MTRR setup. If MTRRs are only set up by the platform
 firmware code though and the OS does not make any specific MTRR mapping
 requests mtrr_type_lookup() should always return MTRR_TYPE_INVALID.
 
-For details refer to Documentation/x86/pat.txt.
-
-===============================================================================
+For details refer to :doc:`pat`.
 
+.. tip::
   On Intel P6 family processors (Pentium Pro, Pentium II and later)
   the Memory Type Range Registers (MTRRs) may be used to control
   processor access to memory ranges. This is most useful when you have
@@ -54,62 +58,72 @@ For details refer to Documentation/x86/pat.txt.
   similar control registers on other processors can be easily
   supported.
 
-
 There are two interfaces to /proc/mtrr: one is an ASCII interface
 which allows you to read and write. The other is an ioctl()
 interface. The ASCII interface is meant for administration. The
 ioctl() interface is meant for C programs (i.e. the X server). The
 interfaces are described below, with sample commands and C code.
 
-===============================================================================
-Reading MTRRs from the shell:
 
-% cat /proc/mtrr
-reg00: base=0x00000000 (   0MB), size= 128MB: write-back, count=1
-reg01: base=0x08000000 ( 128MB), size=  64MB: write-back, count=1
-===============================================================================
-Creating MTRRs from the C-shell:
-# echo "base=0xf8000000 size=0x400000 type=write-combining" >! /proc/mtrr
-or if you use bash:
-# echo "base=0xf8000000 size=0x400000 type=write-combining" >| /proc/mtrr
+Reading MTRRs from the shell
+============================
+::
+
+  % cat /proc/mtrr
+  reg00: base=0x00000000 (   0MB), size= 128MB: write-back, count=1
+  reg01: base=0x08000000 ( 128MB), size=  64MB: write-back, count=1
+
+Creating MTRRs from the C-shell::
+
+  # echo "base=0xf8000000 size=0x400000 type=write-combining" >! /proc/mtrr
 
-And the result thereof:
-% cat /proc/mtrr
-reg00: base=0x00000000 (   0MB), size= 128MB: write-back, count=1
-reg01: base=0x08000000 ( 128MB), size=  64MB: write-back, count=1
-reg02: base=0xf8000000 (3968MB), size=   4MB: write-combining, count=1
+or if you use bash::
+
+  # echo "base=0xf8000000 size=0x400000 type=write-combining" >| /proc/mtrr
+
+And the result thereof::
+
+  % cat /proc/mtrr
+  reg00: base=0x00000000 (   0MB), size= 128MB: write-back, count=1
+  reg01: base=0x08000000 ( 128MB), size=  64MB: write-back, count=1
+  reg02: base=0xf8000000 (3968MB), size=   4MB: write-combining, count=1
 
 This is for video RAM at base address 0xf8000000 and size 4 megabytes. To
 find out your base address, you need to look at the output of your X
 server, which tells you where the linear framebuffer address is. A
-typical line that you may get is:
+typical line that you may get is::
 
-(--) S3: PCI: 968 rev 0, Linear FB @ 0xf8000000
+  (--) S3: PCI: 968 rev 0, Linear FB @ 0xf8000000
 
 Note that you should only use the value from the X server, as it may
 move the framebuffer base address, so the only value you can trust is
 that reported by the X server.
 
 To find out the size of your framebuffer (what, you don't actually
-know?), the following line will tell you:
+know?), the following line will tell you::
 
-(--) S3: videoram:  4096k
+  (--) S3: videoram:  4096k
 
 That's 4 megabytes, which is 0x400000 bytes (in hexadecimal).
 A patch is being written for XFree86 which will make this automatic:
 in other words the X server will manipulate /proc/mtrr using the
 ioctl() interface, so users won't have to do anything. If you use a
 commercial X server, lobby your vendor to add support for MTRRs.
-===============================================================================
-Creating overlapping MTRRs:
 
-%echo "base=0xfb000000 size=0x1000000 type=write-combining" >/proc/mtrr
-%echo "base=0xfb000000 size=0x1000 type=uncachable" >/proc/mtrr
 
-And the results: cat /proc/mtrr
-reg00: base=0x00000000 (   0MB), size=  64MB: write-back, count=1
-reg01: base=0xfb000000 (4016MB), size=  16MB: write-combining, count=1
-reg02: base=0xfb000000 (4016MB), size=   4kB: uncachable, count=1
+Creating overlapping MTRRs
+==========================
+::
+
+  %echo "base=0xfb000000 size=0x1000000 type=write-combining" >/proc/mtrr
+  %echo "base=0xfb000000 size=0x1000 type=uncachable" >/proc/mtrr
+
+And the results::
+
+  % cat /proc/mtrr
+  reg00: base=0x00000000 (   0MB), size=  64MB: write-back, count=1
+  reg01: base=0xfb000000 (4016MB), size=  16MB: write-combining, count=1
+  reg02: base=0xfb000000 (4016MB), size=   4kB: uncachable, count=1
 
 Some cards (especially Voodoo Graphics boards) need this 4 kB area
 excluded from the beginning of the region because it is used for
@@ -117,15 +131,24 @@ registers.
 
 NOTE: You can only create type=uncachable region, if the first
 region that you created is type=write-combining.
-===============================================================================
-Removing MTRRs from the C-shell:
-% echo "disable=2" >! /proc/mtrr
-or using bash:
-% echo "disable=2" >| /proc/mtrr
-===============================================================================
-Reading MTRRs from a C program using ioctl()'s:
 
-/*  mtrr-show.c
+
+Removing MTRRs from the C-shel
+==============================
+::
+
+  % echo "disable=2" >! /proc/mtrr
+
+or using bash::
+
+  % echo "disable=2" >| /proc/mtrr
+
+
+Reading MTRRs from a C program using ioctl()'s
+==============================================
+::
+
+  /*  mtrr-show.c
 
       Source file for mtrr-show (example program to show MTRRs using ioctl()'s)
 
@@ -148,9 +171,9 @@ Reading MTRRs from a C program using ioctl()'s:
       Richard Gooch may be reached by email at  rgooch@atnf.csiro.au
       The postal address is:
         Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
-*/
+  */
 
-/*
+  /*
       This program will use an ioctl() on /proc/mtrr to show the current MTRR
       settings. This is an alternative to reading /proc/mtrr.
 
@@ -160,23 +183,23 @@ Reading MTRRs from a C program using ioctl()'s:
       Last updated by Richard Gooch   2-MAY-1998
 
 
-*/
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#include <errno.h>
-#include <asm/mtrr.h>
+  */
+  #include <stdio.h>
+  #include <stdlib.h>
+  #include <string.h>
+  #include <sys/types.h>
+  #include <sys/stat.h>
+  #include <fcntl.h>
+  #include <sys/ioctl.h>
+  #include <errno.h>
+  #include <asm/mtrr.h>
 
-#define TRUE 1
-#define FALSE 0
-#define ERRSTRING strerror (errno)
+  #define TRUE 1
+  #define FALSE 0
+  #define ERRSTRING strerror (errno)
 
-static char *mtrr_strings[MTRR_NUM_TYPES] =
-{
+  static char *mtrr_strings[MTRR_NUM_TYPES] =
+  {
       "uncachable",               /* 0 */
       "write-combining",          /* 1 */
       "?",                        /* 2 */
@@ -184,10 +207,10 @@ static char *mtrr_strings[MTRR_NUM_TYPES] =
       "write-through",            /* 4 */
       "write-protect",            /* 5 */
       "write-back",               /* 6 */
-};
+  };
 
-int main ()
-{
+  int main ()
+  {
       int fd;
       struct mtrr_gentry gentry;
 
@@ -217,11 +240,14 @@ int main ()
       if (errno == EINVAL) exit (0);
       fprintf (stderr, "Error doing ioctl(2) on /dev/mtrr\t%s\n", ERRSTRING);
       exit (3);
-}   /*  End Function main  */
-===============================================================================
-Creating MTRRs from a C programme using ioctl()'s:
+  }   /*  End Function main  */
+
 
-/*  mtrr-add.c
+Creating MTRRs from a C programme using ioctl()'s
+=================================================
+::
+
+  /*  mtrr-add.c
 
       Source file for mtrr-add (example programme to add an MTRRs using ioctl())
 
@@ -244,9 +270,9 @@ Creating MTRRs from a C programme using ioctl()'s:
       Richard Gooch may be reached by email at  rgooch@atnf.csiro.au
       The postal address is:
         Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
-*/
+  */
 
-/*
+  /*
       This programme will use an ioctl() on /proc/mtrr to add an entry. The first
       available mtrr is used. This is an alternative to writing /proc/mtrr.
 
@@ -256,24 +282,24 @@ Creating MTRRs from a C programme using ioctl()'s:
       Last updated by Richard Gooch   2-MAY-1998
 
 
-*/
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#include <errno.h>
-#include <asm/mtrr.h>
-
-#define TRUE 1
-#define FALSE 0
-#define ERRSTRING strerror (errno)
-
-static char *mtrr_strings[MTRR_NUM_TYPES] =
-{
+  */
+  #include <stdio.h>
+  #include <string.h>
+  #include <stdlib.h>
+  #include <unistd.h>
+  #include <sys/types.h>
+  #include <sys/stat.h>
+  #include <fcntl.h>
+  #include <sys/ioctl.h>
+  #include <errno.h>
+  #include <asm/mtrr.h>
+
+  #define TRUE 1
+  #define FALSE 0
+  #define ERRSTRING strerror (errno)
+
+  static char *mtrr_strings[MTRR_NUM_TYPES] =
+  {
       "uncachable",               /* 0 */
       "write-combining",          /* 1 */
       "?",                        /* 2 */
@@ -281,10 +307,10 @@ static char *mtrr_strings[MTRR_NUM_TYPES] =
       "write-through",            /* 4 */
       "write-protect",            /* 5 */
       "write-back",               /* 6 */
-};
+  };
 
-int main (int argc, char **argv)
-{
+  int main (int argc, char **argv)
+  {
       int fd;
       struct mtrr_sentry sentry;
 
@@ -325,5 +351,4 @@ int main (int argc, char **argv)
       close (fd);
       fputs ("I've just closed /proc/mtrr so now the new entry should be gone\n",
       stderr);
-}   /*  End Function main  */
-===============================================================================
+  }   /*  End Function main  */