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124 commits

Author SHA1 Message Date
Suresh Siddha
f7448548a9 x86, mtrr: Avoid MTRR reprogramming on BP during boot on UP platforms
Markus Kohn ran into a hard hang regression on an acer aspire
1310, when acpi is enabled. git bisect showed the following
commit as the bad one that introduced the boot regression.

	commit d0af9eed5a
	Author: Suresh Siddha <suresh.b.siddha@intel.com>
	Date:   Wed Aug 19 18:05:36 2009 -0700

	    x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init

Because of the UP configuration of that platform,
native_smp_prepare_cpus() bailed out (in smp_sanity_check())
before doing the set_mtrr_aps_delayed_init()

Further down the boot path, native_smp_cpus_done() will call the
delayed MTRR initialization for the AP's (mtrr_aps_init()) with
mtrr_aps_delayed_init not set. This resulted in the boot
processor reprogramming its MTRR's to the values seen during the
start of the OS boot. While this is not needed ideally, this
shouldn't have caused any side-effects. This is because the
reprogramming of MTRR's (set_mtrr_state() that gets called via
set_mtrr()) will check if the live register contents are
different from what is being asked to write and will do the actual
write only if they are different.

BP's mtrr state is read during the start of the OS boot and
typically nothing would have changed when we ask to reprogram it
on BP again because of the above scenario on an UP platform. So
on a normal UP platform no reprogramming of BP MTRR MSR's
happens and all is well.

However, on this platform, bios seems to be modifying the fixed
mtrr range registers between the start of OS boot and when we
double check the live registers for reprogramming BP MTRR
registers. And as the live registers are modified, we end up
reprogramming the MTRR's to the state seen during the start of
the OS boot.

During ACPI initialization, something in the bios (probably smi
handler?) don't like this fact and results in a hard lockup.

We didn't see this boot hang issue on this platform before the
commit d0af9eed5a, because only
the AP's (if any) will program its MTRR's to the value that BP
had at the start of the OS boot.

Fix this issue by checking mtrr_aps_delayed_init before
continuing further in the mtrr_aps_init(). Now, only AP's (if
any) will program its MTRR's to the BP values during boot.

Addresses https://bugzilla.novell.com/show_bug.cgi?id=623393

  [ By the way, this behavior of the bios modifying MTRR's after the start
    of the OS boot is not common and the kernel is not prepared to
    handle this situation well. Irrespective of this issue, during
    suspend/resume, linux kernel will try to reprogram the BP's MTRR values
    to the values seen during the start of the OS boot. So suspend/resume might
    be already broken on this platform for all linux kernel versions. ]

Reported-and-bisected-by: Markus Kohn <jabber@gmx.org>
Tested-by: Markus Kohn <jabber@gmx.org>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Thomas Renninger <trenn@novell.com>
Cc: Rafael Wysocki <rjw@novell.com>
Cc: Venkatesh Pallipadi <venki@google.com>
Cc: stable@kernel.org # [v2.6.32+]
LKML-Reference: <1296694975.4418.402.camel@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03 12:10:38 +01:00
Linus Torvalds
d77bdc423d Merge branch 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, mtrr: Support mtrr lookup for range spanning across MTRR range
  x86, mtrr: Refactor MTRR type overlap check code
2010-10-21 13:51:41 -07:00
Andreas Herrmann
3fdbf004c1 x86, mtrr: Assume SYS_CFG[Tom2ForceMemTypeWB] exists on all future AMD CPUs
Instead of adapting the CPU family check in amd_special_default_mtrr()
for each new CPU family assume that all new AMD CPUs support the
necessary bits in SYS_CFG MSR.

Tom2Enabled is architectural (defined in APM Vol.2).
Tom2ForceMemTypeWB is defined in all BKDGs starting with K8 NPT.
In pre K8-NPT BKDG this bit is reserved (read as zero).

W/o this adaption Linux would unnecessarily complain about bad MTRR
settings on every new AMD CPU family, e.g.

[    0.000000] WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing 4863MB of RAM.

Cc: stable@kernel.org # .32.x, .35.x
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100930123235.GB20545@loge.amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-10-01 16:18:31 -07:00
Venkatesh Pallipadi
351e5a703a x86, mtrr: Support mtrr lookup for range spanning across MTRR range
mtrr_type_lookup [start:end] looked up the resultant MTRR type for that
range, based on fixed and all variable MTRR ranges. It did check for multiple
MTRR var ranges overlapping [start:end] and returned the net type.

However, if the [start:end] range spanned across any var MTRR range,
mtrr_type_lookup would return an error return of 0xFE. This was based on
typical usage of mtrr_type_lookup in PAT mapping, where region being
mapped would not normally span across MTRR ranges and also trying
to keep the code simple.

Mark recently reported the problem with this limitation. When there are
two continguous MTRR's of type "writeback" and if there is a memory mapping
over a region starting in one MTRR range and ending in another MTRR range,
such mapping will fallback to "uncached" due to the above limitation.

Change below adds support for such lookups spanning multiple MTRR ranges.
We now have a wrapper mtrr_type_lookup that dynamically splits such a region
into smaller chunks that fit within one MTRR range and does a
__mtrr_type_lookup on it and combine the results later.

Reported-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
LKML-Reference: <1284159350-19841-3-git-send-email-venki@google.com>
Reviewed-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-09-10 16:11:20 -07:00
Venkatesh Pallipadi
a7f07cfbaa x86, mtrr: Refactor MTRR type overlap check code
Move the MTRR type overlap check into a new function. No functional change in
this patch. Just making it easier to add multiple region overlap check in
the following patch.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
LKML-Reference: <1284159350-19841-2-git-send-email-venki@google.com>
Reviewed-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-09-10 16:11:10 -07:00
Linus Torvalds
75cb5fdce2 Merge branches 'x86-cleanups-for-linus', 'x86-vmware-for-linus', 'x86-mtrr-for-linus', 'x86-apic-for-linus', 'x86-fpu-for-linus' and 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Clean up arch/x86/kernel/cpu/mtrr/cleanup.c: use ";" not "," to terminate statements

* 'x86-vmware-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vmware: Preset lpj values when on VMware.

* 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, mtrr: Use stop machine context to rendezvous all the cpu's

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86/apic/es7000_32: Remove unused variable

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Avoid unnecessary __clear_user() and xrstor in signal handling

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vdso: Unmap vdso pages
2010-08-06 16:22:59 -07:00
Suresh Siddha
68f202e4e8 x86, mtrr: Use stop machine context to rendezvous all the cpu's
Use the stop machine context rather than IPI's to rendezvous all the cpus for
MTRR initialization that happens during cpu bringup or for MTRR modifications
during runtime.

This avoids deadlock scenario (reported by Prarit) like:

cpu A holds a read_lock (tasklist_lock for example) with irqs enabled
cpu B waits for the same lock with irqs disabled using write_lock_irq
cpu C doing set_mtrr() (during AP bringup for example), which will try to
rendezvous all the cpus using IPI's

This will result in C and A come to the rendezvous point and waiting
for B. B is stuck forever waiting for the lock and thus not
reaching the rendezvous point.

Using stop cpu (run in the process context of per cpu based keventd) to do
this rendezvous, avoids this deadlock scenario.

Also make sure all the cpu's are in the rendezvous handler before we proceed
with the local_irq_save() on each cpu. This lock step disabling irqs on all
the cpus will avoid other deadlock scenarios (for example involving
with the blocking smp_call_function's etc).

   [ This problem is very old. Marking -stable only for 2.6.35 as the
     stop_one_cpu_nowait() API is present only in 2.6.35. Any older
     kernel interested in this fix need to do some more work in backporting
     this patch. ]

Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1280515602.2682.10.camel@sbsiddha-MOBL3.sc.intel.com>
Acked-by: Prarit Bhargava <prarit@redhat.com>
Cc: stable@kernel.org	[2.6.35]
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-30 15:59:49 -07:00
Andi Kleen
fa10ba64ac x86, gcc-4.6: Fix set but not read variables
Just some dead code, no real bugs.

Found by gcc 4.6 -Wall

Signed-off-by: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <201007202219.o6KMJnQ0021072@imap1.linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-20 15:38:30 -07:00
Joe Perches
b2691085d1 x86: Clean up arch/x86/kernel/cpu/mtrr/cleanup.c: use ";" not "," to terminate statements
Also needed if pr_<level> becomes a bit more space efficient.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
LKML-Reference: <1277768808.29157.280.camel@Joe-Laptop.home>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-15 18:21:22 +02:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Randy Dunlap
6c550ee415 x86: fix mtrr missing kernel-doc
Fix missing kernel-doc notation in mtrr/main.c:

Warning(arch/x86/kernel/cpu/mtrr/main.c:152): No description found for parameter 'info'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-05 11:46:03 -08:00
Linus Torvalds
a626b46e17 Merge branch 'x86-bootmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-bootmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
  early_res: Need to save the allocation name in drop_range_partial()
  sparsemem: Fix compilation on PowerPC
  early_res: Add free_early_partial()
  x86: Fix non-bootmem compilation on PowerPC
  core: Move early_res from arch/x86 to kernel/
  x86: Add find_fw_memmap_area
  Move round_up/down to kernel.h
  x86: Make 32bit support NO_BOOTMEM
  early_res: Enhance check_and_double_early_res
  x86: Move back find_e820_area to e820.c
  x86: Add find_early_area_size
  x86: Separate early_res related code from e820.c
  x86: Move bios page reserve early to head32/64.c
  sparsemem: Put mem map for one node together.
  sparsemem: Put usemap for one node together
  x86: Make 64 bit use early_res instead of bootmem before slab
  x86: Only call dma32_reserve_bootmem 64bit !CONFIG_NUMA
  x86: Make early_node_mem get mem > 4 GB if possible
  x86: Dynamically increase early_res array size
  x86: Introduce max_early_res and early_res_count
  ...
2010-03-03 08:15:05 -08:00
Linus Torvalds
0091945b47 Merge branch 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Convert set_atomicity_lock to raw_spinlock
  x86, mtrr: Kill over the top warn
  x86, mtrr: Constify struct mtrr_ops
2010-02-28 10:39:16 -08:00
Thomas Gleixner
40d6753e78 x86: Convert set_atomicity_lock to raw_spinlock
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-16 18:03:01 +01:00
Alan Cox
942fa3b63e x86, mtrr: Kill over the top warn
Fixes bugzilla: http://bugzilla.kernel.org/show_bug.cgi?id=12558
Fixes bugzilla: http://bugzilla.kernel.org/show_bug.cgi?id=12317

(and if this really needed to be a warn you'd be responding to the bugs left
in bugzilla from it...)

Signed-off-by: Alan Cox <alan@linux.intel.com>
LKML-Reference: <20100208100239.2568.2940.stgit@localhost.localdomain>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-15 19:38:52 -08:00
Yinghai Lu
e9a0064ad0 x86: Change range end to start+size
So make interface more consistent with early_res.
Later we can share some code with early_res.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-10-git-send-email-yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-10 17:47:17 -08:00
Yinghai Lu
27811d8cab x86: Move range related operation to one file
We have almost the same code for mtrr cleanup and amd_bus checkup, and
this code  will also be used in replacing bootmem with early_res,
so try to move them together and reuse it from different parts.

Also rename update_range to subtract_range as that is what the
function is actually doing.

-v2: update comments as Christoph requested

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-4-git-send-email-yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-10 17:47:17 -08:00
Borislav Petkov
34d2819f20 x86, mtrr: Remove unused mtrr/state.c
The last reference to the helpers in
<arch/x86/kernel/cpu/mtrr/state.c> went away with
9a6b344ea9 leaving unused code.
Remove it.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20100204085128.GA513@liondog.tnic>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-04 10:01:38 +01:00
Emese Revfy
3b9cfc0a99 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>
2010-02-01 11:20:43 -08:00
André Goddard Rosa
e7d2860b69 tree-wide: convert open calls to remove spaces to skip_spaces() lib function
Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.

It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
   text    data     bss     dec     hex filename
  64688     584     592   65864   10148 (TOTALS-BEFORE)
  64641     584     592   65817   10119 (TOTALS-AFTER)

Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".

Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
    drivers/leds/led-class.c
    drivers/leds/ledtrig-timer.c
    drivers/video/output.c

@@
expression str;
@@

( // ignore skip_spaces cases
while (*str &&  isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
Linus Torvalds
e33c019722 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (36 commits)
  x86, mm: Correct the implementation of is_untracked_pat_range()
  x86/pat: Trivial: don't create debugfs for memtype if pat is disabled
  x86, mtrr: Fix sorting of mtrr after subtracting
  x86: Move find_smp_config() earlier and avoid bootmem usage
  x86, platform: Change is_untracked_pat_range() to bool; cleanup init
  x86: Change is_ISA_range() into an inline function
  x86, mm: is_untracked_pat_range() takes a normal semiclosed range
  x86, mm: Call is_untracked_pat_range() rather than is_ISA_range()
  x86: UV SGI: Don't track GRU space in PAT
  x86: SGI UV: Fix BAU initialization
  x86, numa: Use near(er) online node instead of roundrobin for NUMA
  x86, numa, bootmem: Only free bootmem on NUMA failure path
  x86: Change crash kernel to reserve via reserve_early()
  x86: Eliminate redundant/contradicting cache line size config options
  x86: When cleaning MTRRs, do not fold WP into UC
  x86: remove "extern" from function prototypes in <asm/proto.h>
  x86, mm: Report state of NX protections during boot
  x86, mm: Clean up and simplify NX enablement
  x86, pageattr: Make set_memory_(x|nx) aware of NX support
  x86, sleep: Always save the value of EFER
  ...

Fix up conflicts (added both iommu_shutdown and is_untracked_pat_range)
to 'struct x86_platform_ops') in
	arch/x86/include/asm/x86_init.h
	arch/x86/kernel/x86_init.c
2009-12-08 13:27:33 -08:00
Yinghai Lu
5bf65b9ba6 x86, mtrr: Fix sorting of mtrr after subtracting
In some cases we can coalesce MTRR entries after cleanup; this may
allow us to have more entries.  As such, introduce clean_sort_range to
to sort and coaelsce the MTRR entries.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B0BB9A3.5020908@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-11-24 13:06:16 -08:00
Yinghai Lu
508d85c2c6 x86: When cleaning MTRRs, do not fold WP into UC
The current MTRR code treats WP as a form of UC.  This really isn't
desirable behaviour, except possibly in the case of severe MTRR
shortage.  Disable this, to allow legitimate uses of WP to remain
unmolested.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-17 10:26:53 -08:00
Dave Jones
16121d70fd x86: Fix printk message typo in mtrr cleanup code
Trivial typo.

Signed-off-by: Dave Jones <davej@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-02 08:36:18 +01:00
Arjan van de Ven
11879ba5d9 x86: Simplify bound checks in the MTRR code
The current bound checks for copy_from_user in the MTRR driver are
not as obvious as they could be, and gcc agrees with that.

This patch simplifies the boundary checks to the point that gcc can
now prove to itself that the copy_from_user() is never going past
its bounds.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20090926205150.30797709@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-02 19:51:56 +02:00
Joe Perches
9ff6d8e06f x86, mtrr: Convert loop to a while based construct, avoid naked semicolon
Perhaps this is a more readable/standard form.

Signed-off-by: Joe Perches <joe@perches.com>
LKML-Reference: <1252945687.3937.14.camel@Joe-Laptop.home>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-20 20:12:21 +02:00
H. Peter Anvin
5400743db5 x86, mtrr: make mtrr_aps_delayed_init static bool
mtr_aps_delayed_init was declared u32 and made global, but it only
ever takes boolean values and is only ever used in
arch/x86/kernel/cpu/mtrr/main.c.  Declare it "static bool" and remove
external references.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
2009-08-21 17:00:02 -07:00
Suresh Siddha
d0af9eed5a x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init
SDM Vol 3a section titled "MTRR considerations in MP systems" specifies
the need for synchronizing the logical cpu's while initializing/updating
MTRR.

Currently Linux kernel does the synchronization of all cpu's only when
a single MTRR register is programmed/updated. During an AP online
(during boot/cpu-online/resume)  where we initialize all the MTRR/PAT registers,
we don't follow this synchronization algorithm.

This can lead to scenarios where during a dynamic cpu online, that logical cpu
is initializing MTRR/PAT with cache disabled (cr0.cd=1) etc while other logical
HT sibling continue to run (also with cache disabled because of cr0.cd=1
on its sibling).

Starting from Westmere, VMX transitions with cr0.cd=1 don't work properly
(because of some VMX performance optimizations) and the above scenario
(with one logical cpu doing VMX activity and another logical cpu coming online)
can result in system crash.

Fix the MTRR initialization by doing rendezvous of all the cpus. During
boot and resume, we delay the MTRR/PAT init for APs till all the
logical cpu's come online and the rendezvous process at the end of AP's bringup,
will initialize the MTRR/PAT for all AP's.

For dynamic single cpu online, we synchronize all the logical cpus and
do the MTRR/PAT init on the AP that is coming online.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-08-21 16:25:55 -07:00
Ingo Molnar
e3d0e69268 x86: Further clean up of mtrr/generic.c
Yinghai noticed that i defined BIOS_BUG_MSG but added no
usage for it. The usage is to clean up this turd in generic.c:

			printk(KERN_WARNING "WARNING: BIOS bug: VAR MTRR %d "
				"contains strange UC entry under 1M, check "
				"with your system vendor!\n", i);

Breaking printk lines in the middle looks ugly, is hard to read
and breaks 'git grep'. Use the BIOS_BUG_MSG instead.

Also complete the moving of structure definitions and variables
to the top of the file.

Reported-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090703164225.GA21447@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-05 09:46:10 +02:00
Jaswinder Singh Rajput
dbd51be026 x86: Clean up mtrr/main.c
Fix following trivial style problems:

  ERROR: trailing whitespace X 25
  WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
  WARNING: Use #include <linux/kvm_para.h> instead of <asm/kvm_para.h>
  ERROR: do not initialise externals to 0 or NULL X 2
  ERROR: "foo * bar" should be "foo *bar" X 5
  ERROR: do not use assignment in if condition X 2
  WARNING: line over 80 characters X 8
  ERROR: return is not a function, parentheses are not required
  WARNING: braces {} are not necessary for any arm of this statement
  ERROR: space required before the open parenthesis '(' X 2
  ERROR: open brace '{' following function declarations go on the next line
  ERROR: space required after that ',' (ctx:VxV) X 8
  ERROR: space required before the open parenthesis '(' X 3
  ERROR: else should follow close brace '}'
  WARNING: space prohibited between function name and open parenthesis '('
  WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable X 2

Also use pr_debug and pr_warning where possible.

total: 50 errors, 14 warnings

arch/x86/kernel/cpu/mtrr/main.o:

   text	   data	    bss	    dec	    hex	filename
   3668	    116	   4156	   7940	   1f04	main.o.before
   3668	    116	   4156	   7940	   1f04	main.o.after

md5:
   e01af2fd28deef77c8d01e71acfbd365  main.o.before.asm
   e01af2fd28deef77c8d01e71acfbd365  main.o.after.asm

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>
Cc: Avi Kivity <avi@redhat.com> # Avi, please have a look at the kvm_para.h bit
[ More cleanups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:19:55 +02:00
Jaswinder Singh Rajput
09b22c85d5 x86: Clean up mtrr/state.c
Fix:

  WARNING: Use #include <linux/io.h> instead of <asm/io.h>
  WARNING: line over 80 characters X 4

arch/x86/kernel/cpu/mtrr/state.o:

   text	   data	    bss	    dec	    hex	filename
    864	      0	      0	    864	    360	state.o.before
    864	      0	      0	    864	    360	state.o.after

md5:
   c5c4364b9aeac74d70111e1e49667a2c  state.o.before.asm
   c5c4364b9aeac74d70111e1e49667a2c  state.o.after.asm

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 cleanups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:19:53 +02:00
Jaswinder Singh Rajput
3ec8dbcb09 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>
2009-07-04 11:19:52 +02:00
Jaswinder Singh Rajput
26dc67eda1 x86: Clean up mtrr/if.c
Fix:

  WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
  ERROR: trailing whitespace X 7
  ERROR: trailing statements should be on next line X 3
  WARNING: line over 80 characters X 5
  ERROR: space required before the open parenthesis '('

arch/x86/kernel/cpu/mtrr/if.o:

   text	   data	    bss	    dec	    hex	filename
   2239	      4	      0	   2243	    8c3	if.o.before
   2239	      4	      0	   2243	    8c3	if.o.after

md5:
   78d1f2aa4843ec6509c18e2dee54bc7f  if.o.before.asm
   78d1f2aa4843ec6509c18e2dee54bc7f  if.o.after.asm

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 cleanups to make the code more consistent. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:19:48 +02:00
Jaswinder Singh Rajput
a1a499a399 x86: Clean up mtrr/generic.c
Fix following trivial style problems:

  ERROR: trailing whitespace X 4
  WARNING: Use #include <linux/io.h> instead of <asm/io.h>
  WARNING: braces {} are not necessary for single statement blocks X 3
  ERROR: "foo * bar" should be "foo *bar"
  WARNING: line over 80 characters X 6
  ERROR: "foo * bar" should be "foo *bar"
  ERROR: spaces required around that '=' (ctx:VxO)
  ERROR: space required before that '-' (ctx:OxV)
  WARNING: suspect code indent for conditional statements (8, 12)
  ERROR: spaces required around that '=' (ctx:VxV)
  ERROR: do not initialise statics to 0 or NULL
  ERROR: space prohibited after that open parenthesis '(' X 2
  ERROR: space prohibited before that close parenthesis ')' X 2
  ERROR: trailing statements should be on next line
  ERROR: return is not a function, parentheses are not required

Also use pr_debug and pr_warning where possible.

arch/x86/kernel/cpu/mtrr/generic.o:

   text	   data	    bss	    dec	    hex	filename
   5652	     77	   4224	   9953	   26e1	generic.o.before
   5652	     77	   4220	   9949	   26dd	generic.o.after

The md5 changed:
   b34d6c045f06daa4ed092b90cc760e8f  generic.o.before.asm
   a490c6251cfd8442fbffecc0e09a573d  generic.o.after.asm

Because mtrr_state moved from data to bss, changing its
offsets - and also because __LINE__ numbers changed.

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>
[ Further cleanups to make the code more consistent ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:47 +02:00
Jaswinder Singh Rajput
2311037708 x86: Clean up mtrr/cyrix.c
Fix trivial style problems:

  WARNING: Use #include <linux/io.h> instead of <asm/io.h>
  WARNING: line over 80 characters
  ERROR: do not initialise statics to 0 or NULL
  ERROR: space prohibited after that open parenthesis '(' X 2
  ERROR: space prohibited before that close parenthesis ')' X 2
  ERROR: trailing whitespace X 2
  ERROR: trailing statements should be on next line
  ERROR: do not use C99 // comments X 2

arch/x86/kernel/cpu/mtrr/cyrix.o:

   text	   data	    bss	    dec	    hex	filename
   1637	     32	      8	   1677	    68d	cyrix.o.before
   1637	     32	      8	   1677	    68d	cyrix.o.after

md5:
   6f52abd06905be3f4cabb5239f9b0ff0  cyrix.o.before.asm
   6f52abd06905be3f4cabb5239f9b0ff0  cyrix.o.after.asm

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>
[ Made the code more consistent ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:47 +02:00
Jaswinder Singh Rajput
63f9600fad x86: Clean up mtrr/cleanup.c
Fix trivial style problems:

  WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
  WARNING: Use #include <linux/kvm_para.h> instead of <asm/kvm_para.h>

Also, nr_mtrr_spare_reg should be unsigned long.

arch/x86/kernel/cpu/mtrr/cleanup.o:

   text	   data	    bss	    dec	    hex	filename
   6241	   8992	   2056	  17289	   4389	cleanup.o.before
   6241	   8992	   2056	  17289	   4389	cleanup.o.after

The md5 has changed:
   1a7a27513aef1825236daf29110fe657  cleanup.o.before.asm
   bcea358efa2532b6020e338e158447af  cleanup.o.after.asm

Because a WARN_ON()'s __LINE__ value changed by 3 lines.

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>
[ Did lots of other cleanups to make the code look more consistent. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:46 +02:00
Jaswinder Singh Rajput
6c4caa1ab7 x86: Clean up mtrr/centaur.c
Remove dead code and fix trivial style problems:

  ERROR: trailing whitespace X 2
  WARNING: line over 80 characters X 3
  ROR: trailing whitespace
  ERROR: do not use C99 // comments X 2

arch/x86/kernel/cpu/mtrr/centaur.o:

   text	   data	    bss	    dec	    hex	filename
    605	     32	     68	    705	    2c1	centaur.o.before
    605	     32	     68	    705	    2c1	centaur.o.after

md5:
   a4865ea98ce3c163bb1d376a3949b3e3  centaur.o.before.asm
   a4865ea98ce3c163bb1d376a3949b3e3  centaur.o.after.asm

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>
[ Standardized comments, DocBook, curly braces, newlines. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:45 +02:00
Jaswinder Singh Rajput
42204455f1 x86: Clean up mtrr/amd.c:
Fix trivial style problems :

  ERROR: trailing whitespace
  WARNING: line over 80 characters
  ERROR: do not use C99 // comments

arch/x86/kernel/cpu/mtrr/amd.o:

   text	   data	    bss	    dec	    hex	filename
    501	     32	      0	    533	    215	amd.o.before
    501	     32	      0	    533	    215	amd.o.after

md5:
   62f795eb840ee2d17b03df89e789e76c  amd.o.before.asm
   62f795eb840ee2d17b03df89e789e76c  amd.o.after.asm

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>
[ Also restructured comments to be standard, removed stray return,
  converted function description to DocBook style, etc. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:45 +02:00
Linus Torvalds
7dc3ca39cb Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, nmi: Use predefined numbers instead of hardcoded one
  x86: asm/processor.h: remove double declaration
  x86, mtrr: replace MTRRdefType_MSR with msr-index's MSR_MTRRdefType
  x86, mtrr: replace MTRRfix4K_C0000_MSR with msr-index's MSR_MTRRfix4K_C0000
  x86, mtrr: remove mtrr MSRs double declaration
  x86, mtrr: replace MTRRfix16K_80000_MSR with msr-index's MSR_MTRRfix16K_80000
  x86, mtrr: replace MTRRfix64K_00000_MSR with msr-index's MSR_MTRRfix64K_00000
  x86, mtrr: replace MTRRcap_MSR with msr-index's MSR_MTRRcap
  x86: mce: remove duplicated #include
  x86: msr-index.h remove duplicate MSR C001_0015 declaration
  x86: clean up arch/x86/kernel/tsc_sync.c a bit
  x86: use symbolic name for VM86_SIGNAL when used as vm86 default return
  x86: added 'ifndef _ASM_X86_IOMAP_H' to iomap.h
  x86: avoid multiple declaration of kstack_depth_to_print
  x86: vdso/vma.c declare vdso_enabled and arch_setup_additional_pages before they get used
  x86: clean up declarations and variables
  x86: apic/x2apic_cluster.c x86_cpu_to_logical_apicid should be static
  x86 early quirks: eliminate unused function
2009-06-10 15:49:36 -07:00
Jaswinder Singh Rajput
52650257ea 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>
2009-05-15 07:49:01 -07:00
Jaswinder Singh Rajput
ba5673ff1f 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>
2009-05-15 07:49:01 -07:00
Jaswinder Singh Rajput
654ac05801 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>
2009-05-15 07:49:01 -07:00
Jaswinder Singh Rajput
7d9d55e449 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>
2009-05-15 07:49:00 -07:00
Jaswinder Singh Rajput
a036c7a358 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>
2009-05-15 07:49:00 -07:00
Jaswinder Singh Rajput
d9bcc01d58 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>
2009-05-15 07:49:00 -07:00
Yinghai Lu
917a015362 x86: mtrr: Fix high_width computation when phys-addr is >= 44bit
found one system where cpu address line is 44bits, mtrr printout
is not right:

 [    0.000000] MTRR variable ranges enabled:
 [    0.000000]   0 base 0   00000000 mask FF0 00000000 write-back
 [    0.000000]   1 base 10  00000000 mask FFF 80000000 write-back
 [    0.000000]   2 base 0   80000000 mask FFF 80000000 uncachable
 [    0.000000]   3 base 0   7F800000 mask FFF FF800000 uncachable

Li Zefan and Frederic pointed out the high_width could be -4 some how.

It turns out when phys_addr is 44bit, size_or_mask will be
ffffffff,00000000 so ffs(size_or_mask) will be 0.

Try to check low 32 bit, to get correct high_width.

Signed-off-by: Yinghai Lu <yinghai@kerne.org>
Also-analyzed-by: Frederic Weisbecker <fweisbec@gmail.com>
Also-analyzed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A026540.8060504@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-11 11:40:43 +02:00
Ingo Molnar
c5c67c7cba x86, mtrr: remove debug message
The MTRR code grew a new debug message which triggers commonly:

[   40.142276]   get_mtrr: cpu0 reg00 base=0000000000 size=0000080000 write-back
[   40.142280]   get_mtrr: cpu0 reg01 base=0000080000 size=0000040000 write-back
[   40.142284]   get_mtrr: cpu0 reg02 base=0000100000 size=0000040000 write-back
[   40.142311]   get_mtrr: cpu0 reg00 base=0000000000 size=0000080000 write-back
[   40.142314]   get_mtrr: cpu0 reg01 base=0000080000 size=0000040000 write-back
[   40.142317]   get_mtrr: cpu0 reg02 base=0000100000 size=0000040000 write-back

Remove this annoyance.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-04 00:31:02 +02:00
Alexey Dobriyan
99b7623380 proc 2/2: remove struct proc_dir_entry::owner
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-03-31 01:14:44 +04:00
Jaswinder Singh Rajput
4e16c88875 x86: cpu/mttr/cleanup.c fix compilation warning
arch/x86/kernel/cpu/mtrr/cleanup.c:197: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1237378015.13488.1.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18 13:14:31 +01:00
Yinghai Lu
f0348c438c 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>
2009-03-17 10:47:47 +01:00