History log of /linux-master/arch/x86/kernel/cpu/mtrr/mtrr.h
Revision Date Author Comments
# 7c1dee73 31-May-2023 Borislav Petkov (AMD) <bp@alien8.de>

x86/mtrr: Unify debugging printing

Put all the debugging output behind "mtrr=debug" and get rid of
"mtrr_cleanup_debug" which wasn't even documented anywhere.

No functional changes.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230531174857.GDZHeIib57h5lT5Vh1@fat_crate.local


# 061b984a 02-May-2023 Juergen Gross <jgross@suse.com>

x86/mtrr: Construct a memory map with cache modes

After MTRR initialization construct a memory map with cache modes from
MTRR values. This will speed up lookups via mtrr_lookup_type()
especially in case of overlapping MTRRs.

This will be needed when switching the semantics of the "uniform"
parameter of mtrr_lookup_type() from "only covered by one MTRR" to
"memory range has a uniform cache mode", which is the data the callers
really want to know. Today this information is not easily available,
in case MTRRs are not well sorted regarding base address.

The map will be built in __initdata. When memory management is up, the
map will be moved to dynamically allocated memory, in order to avoid
the need of an overly large array. The size of this array is calculated
using the number of variable MTRR registers and the needed size for
fixed entries.

Only add the map creation and expansion for now. The lookup will be
added later.

When writing new MTRR entries in the running system rebuild the map
inside the call from mtrr_rendezvous_handler() in order to avoid nasty
race conditions with concurrent lookups.

[ bp: Move out rebuild_map() call and rename it. ]

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230502120931.20719-12-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>


# b5d3c728 02-May-2023 Juergen Gross <jgross@suse.com>

x86/mtrr: Move 32-bit code from mtrr.c to legacy.c

There is some code in mtrr.c which is relevant for old 32-bit CPUs
only. Move it to a new source legacy.c.

While modifying mtrr_init_finalize() fix spelling of its name.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230502120931.20719-9-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>


# 03409069 02-May-2023 Juergen Gross <jgross@suse.com>

x86/mtrr: Replace vendor tests in MTRR code

Modern CPUs all share the same MTRR interface implemented via
generic_mtrr_ops.

At several places in MTRR code this generic interface is deduced via
is_cpu(INTEL) tests, which is only working due to X86_VENDOR_INTEL
being 0 (the is_cpu() macro is testing mtrr_if->vendor, which isn't
explicitly set in generic_mtrr_ops).

Test the generic CPU feature X86_FEATURE_MTRR instead.

The only other place where the .vendor member of struct mtrr_ops is
being used is in set_num_var_ranges(), where depending on the vendor
the number of MTRR registers is determined. This can easily be changed
by replacing .vendor with the static number of MTRR registers.

It should be noted that the test "is_cpu(HYGON)" wasn't ever returning
true, as there is no struct mtrr_ops with that vendor information.

[ bp: Use mtrr_enabled() before doing mtrr_if-> accesses, esp. in
mtrr_trim_uncached_memory() which gets called independently from
whether mtrr_if is set or not. ]

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230502120931.20719-7-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>


# d053b481 02-May-2023 Juergen Gross <jgross@suse.com>

x86/mtrr: Replace size_or_mask and size_and_mask with a much easier concept

Replace size_or_mask and size_and_mask with the much easier concept of
high reserved bits.

While at it, instead of using constants in the MTRR code, use some new

[ bp:
- Drop mtrr_set_mask()
- Unbreak long lines
- Move struct mtrr_state_type out of the uapi header as it doesn't
belong there. It also fixes a HDRTEST breakage "unknown type name ‘bool’"
as Reported-by: kernel test robot <lkp@intel.com>
- Massage.
]

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230502120931.20719-3-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>


# f6b98064 02-May-2023 Juergen Gross <jgross@suse.com>

x86/mtrr: Remove physical address size calculation

The physical address width calculation in mtrr_bp_init() can easily be
replaced with using the already available value x86_phys_bits from
struct cpuinfo_x86.

The same information source can be used in mtrr/cleanup.c, removing the
need to pass that value on to mtrr_cleanup().

In print_mtrr_state() use x86_phys_bits instead of recalculating it
from size_or_mask.

Move setting of size_or_mask and size_and_mask into a dedicated new
function in mtrr/generic.c, enabling to make those 2 variables static,
as they are used in generic.c only now.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230502120931.20719-2-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>


# f8bd9f25 02-Nov-2022 Juergen Gross <jgross@suse.com>

x86/mtrr: Simplify mtrr_ops initialization

The way mtrr_if is initialized with the correct mtrr_ops structure is
quite weird.

Simplify that by dropping the vendor specific init functions and the
mtrr_ops[] array. Replace those with direct assignments of the related
vendor specific ops array to mtrr_if.

Note that a direct assignment is okay even for 64-bit builds, where the
symbol isn't present, as the related code will be subject to "dead code
elimination" due to how cpu_feature_enabled() is implemented.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221102074713.21493-17-jgross@suse.com
Signed-off-by: Borislav Petkov <bp@suse.de>


# 74069135 02-Nov-2022 Juergen Gross <jgross@suse.com>

x86/mtrr: Simplify mtrr_bp_init()

In case of the generic cache interface being used (Intel CPUs or a
64-bit system), the initialization sequence of the boot CPU is more
complicated than necessary:

- check if MTRR enabled, if yes, call mtrr_bp_pat_init() which will
disable caching, set the PAT MSR, and reenable caching

- call mtrr_cleanup(), in case that changed anything, call
cache_cpu_init() doing the same caching disable/enable dance as
above, but this time with setting the (modified) MTRR state (even
if MTRR was disabled) AND setting the PAT MSR (again even with
disabled MTRR)

The sequence can be simplified a lot while removing potential
inconsistencies:

- check if MTRR enabled, if yes, call mtrr_cleanup() and then
cache_cpu_init()

This ensures to:

- no longer disable/enable caching more than once

- avoid to set MTRRs and/or the PAT MSR on the boot processor in case
of MTRR cleanups even if MTRRs meant to be disabled

With that mtrr_bp_pat_init() can be removed.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221102074713.21493-10-jgross@suse.com
Signed-off-by: Borislav Petkov <bp@suse.de>


# 57df636c 02-Nov-2022 Juergen Gross <jgross@suse.com>

x86/mtrr: Remove set_all callback from struct mtrr_ops

Instead of using an indirect call to mtrr_if->set_all just call the only
possible target cache_cpu_init() directly. Remove the set_all function
pointer from struct mtrr_ops.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221102074713.21493-9-jgross@suse.com
Signed-off-by: Borislav Petkov <bp@suse.de>


# 45fa71f1 02-Nov-2022 Juergen Gross <jgross@suse.com>

x86/mtrr: Replace use_intel() with a local flag

In MTRR code use_intel() is only used in one source file, and the
relevant use_intel_if member of struct mtrr_ops is set only in
generic_mtrr_ops.

Replace use_intel() with a single flag in cacheinfo.c which can be
set when assigning generic_mtrr_ops to mtrr_if. This allows to drop
use_intel_if from mtrr_ops, while preparing to decouple PAT from MTRR.
As another preparation for the PAT/MTRR decoupling use a bit for MTRR
control and one for PAT control. For now set both bits together, this
can be changed later.

As the new flag will be set only if mtrr_enabled is set, the test for
mtrr_enabled can be dropped at some places.

[ bp: Massage commit message. ]

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221102074713.21493-4-jgross@suse.com
Signed-off-by: Borislav Petkov <bp@suse.de>


# b2441318 01-Nov-2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 404f6aac 08-Aug-2016 Kees Cook <keescook@chromium.org>

x86: Apply more __ro_after_init and const

Guided by grsecurity's analogous __read_only markings in arch/x86,
this applies several uses of __ro_after_init to structures that are
only updated during __init, and const for some structures that are
never updated. Additionally extends __init markings to some functions
that are only used during __init, and cleans up some missing C99 style
static initializers.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Link: http://lkml.kernel.org/r/20160808232906.GA29731@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>


# ad025a73 23-Mar-2016 Toshi Kani <toshi.kani@hpe.com>

x86/mtrr: Fix PAT init handling when MTRR is disabled

get_mtrr_state() calls pat_init() on BSP even if MTRR is disabled.
This results in calling pat_init() on BSP only since APs do not call
pat_init() when MTRR is disabled. This inconsistency between BSP
and APs leads to undefined behavior.

Make BSP's calling condition to pat_init() consistent with AP's,
mtrr_ap_init() and mtrr_aps_init().

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-6-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>


# f9626104 26-May-2015 Luis R. Rodriguez <mcgrof@suse.com>

x86/mm/mtrr: Generalize runtime disabling of MTRRs

It is possible to enable CONFIG_MTRR and CONFIG_X86_PAT and end
up with a system with MTRR functionality disabled but PAT
functionality enabled. This can happen, for instance, when the
Xen hypervisor is used where MTRRs are not supported but PAT is.
This can happen on Linux as of commit

47591df50512 ("xen: Support Xen pv-domains using PAT")

by Juergen, introduced in v3.19.

Technically, we should assume the proper CPU bits would be set
to disable MTRRs but we can't always rely on this. At least on
the Xen Hypervisor, for instance, only X86_FEATURE_MTRR was
disabled as of Xen 4.4 through Xen commit 586ab6a [0], but not
X86_FEATURE_K6_MTRR, X86_FEATURE_CENTAUR_MCR, or
X86_FEATURE_CYRIX_ARR for instance.

Roger Pau Monné has clarified though that although this is
technically true we will never support PVH on these CPU types so
Xen has no need to disable these bits on those systems. As per
Roger, AMD K6, Centaur and VIA chips don't have the necessary
hardware extensions to allow running PVH guests [1].

As per Toshi it is also possible for the BIOS to disable MTRR
support, in such cases get_mtrr_state() would update the MTRR
state as per the BIOS, we need to propagate this information as
well.

x86 MTRR code relies on quite a bit of checks for mtrr_if being
set to check to see if MTRRs did get set up. Instead, lets
provide a generic getter for that. This also adds a few checks
where they were not before which could potentially safeguard
ourselves against incorrect usage of MTRR where this was not
desirable.

Where possible match error codes as if MTRRs were disabled on
arch/x86/include/asm/mtrr.h.

Lastly, since disabling MTRRs can happen at run time and we
could end up with PAT enabled, best record now in our logs when
MTRRs are disabled.

[0] ~/devel/xen (git::stable-4.5)$ git describe --contains 586ab6a 4.4.0-rc1~18
[1] http://lists.xenproject.org/archives/html/xen-devel/2015-03/msg03460.html

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: bhelgaas@google.com
Cc: david.vrabel@citrix.com
Cc: jbeulich@suse.com
Cc: konrad.wilk@oracle.com
Cc: venkatesh.pallipadi@intel.com
Cc: ville.syrjala@linux.intel.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1426893517-2511-3-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1432628901-18044-12-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>


# 3b9cfc0a 31-Jan-2010 Emese Revfy <re.emese@gmail.com>

x86, mtrr: Constify struct mtrr_ops

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime

* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime

* potentially better optimized code as the compiler
can assume that the const data cannot be changed

* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
LKML-Reference: <4B65D712.3080804@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# 3ec8dbcb 03-Jul-2009 Jaswinder Singh Rajput <jaswinder@kernel.org>

x86: Clean up mtrr/mtrr.h

Fix:

ERROR: do not use C99 // comments
ERROR: "foo * bar" should be "foo *bar" X 2

Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090703164225.GA21447@elte.hu>
[ More tidyups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>


# 52650257 13-May-2009 Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

x86, mtrr: replace MTRRdefType_MSR with msr-index's MSR_MTRRdefType

Use standard msr-index.h's MSR declaration and no need to declare again.

[ Impact: cleanup, no object code change ]

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# ba5673ff 13-May-2009 Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

x86, mtrr: replace MTRRfix4K_C0000_MSR with msr-index's MSR_MTRRfix4K_C0000

Use standard msr-index.h's MSR declaration and no need to declare again.

[ Impact: cleanup, no object code change ]

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# 654ac058 13-May-2009 Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

x86, mtrr: remove mtrr MSRs double declaration

Removed MTRR MSR from mtrr/mtrr.h as these are already declared in
msr-index.h and nobody is using them:
MTRRfix16K_A0000_MSR
MTRRfix4K_C8000_MSR
MTRRfix4K_D0000_MSR
MTRRfix4K_D8000_MSR
MTRRfix4K_E0000_MSR
MTRRfix4K_E8000_MSR
MTRRfix4K_F0000_MSR
MTRRfix4K_F8000_MSR

Use standard msr-index.h's MSR declaration and no need to declare again

[ Impact: cleanup, no object code change ]

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# 7d9d55e4 13-May-2009 Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

x86, mtrr: replace MTRRfix16K_80000_MSR with msr-index's MSR_MTRRfix16K_80000

Use standard msr-index.h's MSR declaration and no need to declare again

[ Impact: cleanup, no object code change ]

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# a036c7a3 13-May-2009 Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

x86, mtrr: replace MTRRfix64K_00000_MSR with msr-index's MSR_MTRRfix64K_00000

Use standard msr-index.h's MSR declaration and no need to declare again.

[ Impact: cleanup, no object code change ]

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# d9bcc01d 13-May-2009 Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

x86, mtrr: replace MTRRcap_MSR with msr-index's MSR_MTRRcap

Use standard msr-index.h's MSR declaration and no need to declare again.

[ Impact: cleanup, no object code change ]

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>


# f0348c43 16-Mar-2009 Yinghai Lu <yinghai@kernel.org>

x86: MTRR workaround for system with stange var MTRRs

Impact: don't trim e820 according to wrong mtrr

Ozan reports that his server emits strange warning.
it turns out the BIOS sets the MTRRs incorrectly.

Ignore those strange ranges, and don't trim e820,
just emit one warning about BIOS

Reported-by: Ozan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49BEE1E7.7020706@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


# 0d890355 11-Mar-2009 Yinghai Lu <yinghai@kernel.org>

x86: separate mtrr cleanup/mtrr_e820 trim to separate file

Impact: cleanup

mtrr main.c is too big, seperate mtrr cleanup and mtrr e820 trim
code to another file.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B87C7B.80809@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


# 932d27a7 09-Oct-2008 Sheng Yang <sheng@linux.intel.com>

x86: Export some definition of MTRR

For KVM can reuse the type define, and need them to support shadow MTRR.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>


# b558bc0a 09-Oct-2008 Sheng Yang <sheng@linux.intel.com>

x86: Rename mtrr_state struct and macro names

Prepare for exporting them.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>


# 95ffa243 29-Apr-2008 Yinghai Lu <yhlu.kernel.send@gmail.com>

x86: mtrr cleanup for converting continuous to discrete layout, v8

some BIOS like to use continus MTRR layout, and X driver can not add
WB entries for graphical cards when 4g or more RAM installed.

the patch will change MTRR to discrete.

mtrr_chunk_size= could be used to have smaller continuous block to hold holes.
default is 256m, could be set according to size of graphics card memory.

mtrr_gran_size= could be used to send smallest mtrr block to avoid run out of MTRRs

v2: fix -1 for UC checking
v3: default to disable, and need use enable_mtrr_cleanup to enable this feature
skip the var state change warning.
remove next_basek in range_to_mtrr()
v4: correct warning mask.
v5: CONFIG_MTRR_SANITIZER
v6: fix 1g, 2g, 512 aligment with extra hole
v7: gran_sizek to prevent running out of MTRRs.
v8: fix hole_basek caculation caused when removing next_basek
gran_sizek using when basek is 0.

need to apply
[PATCH] x86: fix trimming e820 with MTRR holes.
right after this one.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>


# 16c02ed7 04-Feb-2008 Harvey Harrison <harvey.harrison@gmail.com>

x86: add cpu mtrr init function definitions to mtrr.h

mtrr.h was included everywhere needed. Fixes the following sparse
warnings. Also, the return types in the extern definitions were
incorrect.

arch/x86/kernel/cpu/mtrr/amd.c:113:12: warning: symbol 'amd_init_mtrr' was not declared. Should it be static?
arch/x86/kernel/cpu/mtrr/cyrix.c:268:12: warning: symbol 'cyrix_init_mtrr' was not declared. Should it be static?
arch/x86/kernel/cpu/mtrr/centaur.c:218:12: warning: symbol 'centaur_init_mtrr' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>


# 99fc8d42 30-Jan-2008 Jesse Barnes <jesse.barnes@intel.com>

x86, 32-bit: trim memory not covered by wb mtrrs

On some machines, buggy BIOSes don't properly setup WB MTRRs to cover all
available RAM, meaning the last few megs (or even gigs) of memory will be
marked uncached. Since Linux tends to allocate from high memory addresses
first, this causes the machine to be unusably slow as soon as the kernel
starts really using memory (i.e. right around init time).

This patch works around the problem by scanning the MTRRs at boot and
figuring out whether the current end_pfn value (setup by early e820 code)
goes beyond the highest WB MTRR range, and if so, trimming it to match. A
fairly obnoxious KERN_WARNING is printed too, letting the user know that
not all of their memory is available due to a likely BIOS bug.

Something similar could be done on i386 if needed, but the boot ordering
would be slightly different, since the MTRR code on i386 depends on the
boot_cpu_data structure being setup.

This patch fixes a bug in the last patch that caused the code to run on
non-Intel machines (AMD machines apparently don't need it and it's untested
on other non-Intel machines, so best keep it off).

Further enhancements and fixes from:

Yinghai Lu <Yinghai.Lu@Sun.COM>
Andi Kleen <ak@suse.de>

Signed-off-by: Jesse Barnes <jesse.barnes@intel.com>
Tested-by: Justin Piszcz <jpiszcz@lucidpixels.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>


# 2d2ee8de 30-Jan-2008 Paul Jimenez <pj@place.org>

x86: mtrr use type bool [RESEND AGAIN]

This is a janitorish patch to 1) remove private TRUE/FALSE #def's in
favor of using the standard enum from linux/stddef.h and 2) switch the
variables holding those values to type 'bool' (from linux/types.h)
since it both seems more appropriate and allows for potentially better
optimization.

As a truly minor aside, I removed a couple of comments documenting
a 'do_safe' parameter that seems to no longer exist.

Signed-off-by: Paul Jimenez <pj@place.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>


# 2ec1df41 11-Oct-2007 Thomas Gleixner <tglx@linutronix.de>

i386: move kernel/cpu/mtrr

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>