arch/x86/mtrr.rst

55   The CONFIG_MTRR option creates a /proc/mtrr file which may be used
61 There are two interfaces to /proc/mtrr: one is an ASCII interface
72   % cat /proc/mtrr
78   # echo "base=0xf8000000 size=0x400000 type=write-combining" >! /proc/mtrr
82   # echo "base=0xf8000000 size=0x400000 type=write-combining" >| /proc/mtrr
86   % cat /proc/mtrr
109 in other words the X server will manipulate /proc/mtrr using the
118   %echo "base=0xfb000000 size=0x1000000 type=write-combining" >/proc/mtrr
119   %echo "base=0xfb000000 size=0x1000 type=uncachable" >/proc/mtrr
123   % cat /proc/mtrr
140   % echo "disable=2" >! /proc/mtrr
144   % echo "disable=2" >| /proc/mtrr
151   /*  mtrr-show.c
153       Source file for mtrr-show (example program to show MTRRs using ioctl()'s)
177       This program will use an ioctl() on /proc/mtrr to show the current MTRR
178       settings. This is an alternative to reading /proc/mtrr.
195   #include <asm/mtrr.h>
217       if ( ( fd = open ("/proc/mtrr", O_RDONLY, 0) ) == -1 )
221         fputs ("/proc/mtrr not found: not supported or you don't have a PPro?\n",
225     fprintf (stderr, "Error opening /proc/mtrr\t%s\n", ERRSTRING);
241       fprintf (stderr, "Error doing ioctl(2) on /dev/mtrr\t%s\n", ERRSTRING);
250   /*  mtrr-add.c
252       Source file for mtrr-add (example programme to add an MTRRs using ioctl())
276       This programme will use an ioctl() on /proc/mtrr to add an entry. The first
277       available mtrr is used. This is an alternative to writing /proc/mtrr.
295   #include <asm/mtrr.h>
333       if ( ( fd = open ("/proc/mtrr", O_WRONLY, 0) ) == -1 )
337         fputs ("/proc/mtrr not found: not supported or you don't have a PPro?\n",
341     fprintf (stderr, "Error opening /proc/mtrr\t%s\n", ERRSTRING);
346     fprintf (stderr, "Error doing ioctl(2) on /dev/mtrr\t%s\n", ERRSTRING);
352       fputs ("I've just closed /proc/mtrr so now the new entry should be gone\n",