diff options
author | Matthieu Herrb <matthieu@cvs.openbsd.org> | 1999-11-20 11:11:29 +0000 |
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committer | Matthieu Herrb <matthieu@cvs.openbsd.org> | 1999-11-20 11:11:29 +0000 |
commit | 100c78df16f1a855aebc02c646996cdaaa22f580 (patch) | |
tree | 4e3559e2b00bdd9cfe875f9ff3f0cfe4ef2334d9 /share/man/man4/man4.i386 | |
parent | 5c49efebb293cf607c240efa71357e01440f9384 (diff) |
add MTRR support from FreeBSD
Diffstat (limited to 'share/man/man4/man4.i386')
-rw-r--r-- | share/man/man4/man4.i386/mtrr.4 | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/share/man/man4/man4.i386/mtrr.4 b/share/man/man4/man4.i386/mtrr.4 new file mode 100644 index 00000000000..8934371e241 --- /dev/null +++ b/share/man/man4/man4.i386/mtrr.4 @@ -0,0 +1,138 @@ +.\" $OpenBSD: mtrr.4,v 1.1 1999/11/20 11:11:28 matthieu Exp $ +.\" +.\" Pentium MTRR driver for OpenBSD. +.\" Copyright 1999 Matthieu Herrb <matthieu@openbsd.org> +.\" +.\" Modification and redistribution in source and binary forms is +.\" permitted provided that due credit is given to the author and the +.\" OpenBSD project (for instance by leaving this copyright notice +.\" intact). +.\" +.Dd November 15, 1999 +.Dt MTRR 4 i386 +.Os +.Sh NAME +.Nm mtrr +.Nd driver for cpu performance counters +.Sh SYNOPSIS +.Cd pseudo-device mtrr +.Sh DESCRIPTION +The +.Nm +device provides access to the memory range attributes supported by the +MTRRs on pentiums. +.Pp +.Ss IOCTL INTERFACE +Several architectures allow attributes to be associated with ranges of physical +memory. These attributes can be manipulated via +.Fn ioctl +calls performed on +.Nm /dev/mem +or +.Nm /dev/xf86 . +Declarations and data types are to be found in +.Pa <memrange.h> +.Pp +The specific attributes, and number of programmable ranges may vary between +architectures. The full set of supported attributes is: +.Bl -tag -width 10 +.It MDF_UNCACHEABLE +The region is not cached. +.It MDF_WRITECOMBINE +Writes to the region may be combined or performed out of order. +.It MDF_WRITETHROUGH +Writes to the region are committed synchronously. +.It MDF_WRITEBACK +Writes to the region are committed asynchronously. +.It MDF_WRITEPROTECT +The region cannot be written to. +.El +.Pp +Memory ranges are described by +.Fa struct mem_range_desc : +.Bd -literal -offset indent +u_int64_t mr_base; /\(** physical base address \(**/ +u_int64_t mr_len; /\(** physical length of region \(**/ +int mr_flags; /\(** attributes of region \(**/ +char mr_owner[8]; +.Ed +.Pp +In addition to the region attributes listed above, the following flags +may also be set in the +.Fa mr_flags +field: +.Bl -tag -width 10 +.It MDF_FIXBASE +The region's base address cannot be changed. +.It MDF_FIXLEN +The region's length cannot be changed. +.It MDF_FIRMWARE +The region is believed to have been established by the system firmare. +.It MDF_ACTIVE +The region is currently active. +.It MDF_BOGUS +We believe the region to be invalid or otherwise erroneous. +.It MDF_FIXACTIVE +The region cannot be disabled. +.It MDF_BUSY +The region is currently owned by another process and may not be +altered. +.El +.Pp +Operations are performed using +.Fa struct mem_range_op : +.Bd -literal -offset indent +struct mem_range_desc *mo_desc; +int mo_arg[2]; +.Ed +.Pp +The +.Fa MEMRANGE_GET +ioctl is used to retrieve current memory range attributes. If +.Fa mo_arg[0] +is set to 0, it will be updated with the total number of memory range +descriptors. If greater than 0, the array at +.Fa mo_desc +will be filled with a corresponding number of descriptor structures, +or the maximum, whichever is less. +.Pp +The +.Fa MEMRANGE_SET +ioctl is used to add, alter and remove memory range attributes. A range +with the MDF_FIXACTIVE flag may not be removed; a range with the MDF_BUSY +flag may not be removed or updated. +.Pp +.Fa mo_arg[0] +should be set to MEMRANGE_SET_UPDATE to update an existing +or establish a new range, or to MEMRANGE_SET_REMOVE to remove a range. +.Pp +.Sh RETURN VALUES +.Bl -tag -width 10 +.It EOPNOTSUPP +Memory range operations are not supported on this architecture. +.It ENXIO +No memory range descriptors are available (eg. firmware has not enabled +any). +.It EINVAL +The memory range supplied as an argument is invalid or overlaps another +range in a fashion not supported by this architecture. +.It EBUSY +An attempt to remove or update a range failed because the range is busy. +.It ENOSPC +An attempt to create a new range failed due to a shortage of hardware +resources (eg. descriptor slots). +.It ENOENT +An attempt to remove a range failed because no range matches the descriptor +base/length supplued. +.It EPERM +An attempt to remove a range failed because the range is permanently +enabled. +.El +.Sh SEE ALSO +.Xr ioctl 2 , +.Xr mem 4 , +.Xr xf86 4 , +.Xr memconfig 8 +.Sh HISTORY +.Nm +support was originally included in FreeBSD 3.3. |