Processors synchronization in set_mtrr requires the .gate field to be set
after .count field is properly initialized. Without an explicit barrier,
the compiler was reordering those memory stores. That was sometimes
causing a processor (in ipi_handler) to see the .gate change and decrement
.count before the latter is set by set_mtrr() (which then hangs in a
infinite loop with irqs disabled).
Signed-off-by: Loic Prylli <loic@myri.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 3ebad59056 ("[PATCH] x86: Save and
restore the fixed-range MTRRs of the BSP when suspending") added mtrr
operations without verifying that the CPU has MTRRs. Crashes transmeta
CPUs.
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux@horizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 9215da3320 "fixed" the MTRR range
check to not allow any MTRR's under the 1MB mark (since that's where the
fixed MTRR's are active).
However, that was totally bogus, since it's normal (and almost required)
to have a large variable MTRR that starts at 0, and covers some large
percentage of the whole RAM, and then using the fixed MTRR's to override
that large MTRR to handle the special ISA hole in the 640k-1M region.
The old check was bogus too (checking that no variable MTRR is used that
is entirely under the 1MB range), but at least it wasn't actively
detrimental, because no sane situation would ever trigger such MTRR
usage in the first place.
That said, the whole notion of not allowing variable MTRR's in the low
1MB is just stupid, so rather than revert the commit, this just removes
the whole sad and unnecessary check entirely.
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Luca Palermo <darkmage@sabayonlinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WARNING: arch/x86_64/kernel/built-in.o(.text+0xace9): Section mismatch: reference to .init.text: (between 'get_mtrr_state' and 'mtrr_wrmsr')
WARNING: arch/x86_64/kernel/built-in.o(.text+0xad09): Section mismatch: reference to .init.text: (between 'get_mtrr_state' and 'mtrr_wrmsr')
WARNING: arch/x86_64/kernel/built-in.o(.text+0xad38): Section mismatch: reference to .init.text: (between 'get_mtrr_state' and 'mtrr_wrmsr')
WARNING: drivers/built-in.o(.text+0x3a680): Section mismatch: reference to .init.text:acpi_map_pxm_to_node (between 'acpi_get_node' and 'acpi_lock_ac_dir')
AK: also marked mtrr_bp_init __init to avoid some more warnings
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rafael gets this on an SMP box with kernel preemption enabled, during
hibernation and restore (100% of the time):
Enabling non-boot CPUs ...
BUG: using smp_processor_id() in preemptible [00000001] code: bash/4514
caller is mtrr_save_state+0x9/0x40
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cr4 is a 32-bit register, so casting the mask to an unsigned char is wrong,
as it clears more than the PGE bit.
Signed-off-by: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to
.init.text:mtrr_bp_init from .text between 'id entify_cpu' (at offset 0x6571)
and 'IRQ0x20_interrupt'
It's because identify_cpu() which is __cpuinit calls mtrr_bp_init() which is
__init(). __cpuinit() expands to nothing if CONFIG_HOTPLUG_CPU=y and so the
call is illegal.
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix section mismatch warnings in mtrr code.
Fix line length on one source line.
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data: from .text.get_mtrr_state after 'get_mtrr_state' (at offset 0x103)
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text: from .text.get_mtrr_state after 'get_mtrr_state' (at offset 0x180)
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text: from .text.get_mtrr_state after 'get_mtrr_state' (at offset 0x199)
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text: from .text.get_mtrr_state after 'get_mtrr_state' (at offset 0x1c1)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If our copy of the MTRRs of the BSP has RdMem or WrMem set, and
we are running on an AMD64/K8 system, the boot CPU must have had
MtrrFixDramEn and MtrrFixDramModEn set (otherwise our RDMSR would
have copied these bits cleared), so we set them on this CPU as well.
This allows us to keep the AMD64/K8 RdMem and WrMem bits in sync
across the CPUs of SMP systems in order to fullfill the duty of
system software to "initialize and maintain MTRR consistency
across all processors." as written in the AMD and Intel manuals.
If an WRMSR instruction fails because MtrrFixDramModEn is not
set, I expect that also the Intel-style MTRR bits are not updated.
AK: minor cleanup, moved MSR defines around
Signed-off-by: Bernhard Kaindl <bk@suse.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Dave Jones <davej@codemonkey.org.uk>
Applied fix by Andew Morton:
http://lkml.org/lkml/2007/4/8/88 - Fix `make headers_check'.
AMD and Intel x86 CPU manuals state that it is the responsibility of
system software to initialize and maintain MTRR consistency across
all processors in Multi-Processing Environments.
Quote from page 188 of the AMD64 System Programming manual (Volume 2):
7.6.5 MTRRs in Multi-Processing Environments
"In multi-processing environments, the MTRRs located in all processors must
characterize memory in the same way. Generally, this means that identical
values are written to the MTRRs used by the processors." (short omission here)
"Failure to do so may result in coherency violations or loss of atomicity.
Processor implementations do not check the MTRR settings in other processors
to ensure consistency. It is the responsibility of system software to
initialize and maintain MTRR consistency across all processors."
Current Linux MTRR code already implements the above in the case that the
BIOS does not properly initialize MTRRs on the secondary processors,
but the case where the fixed-range MTRRs of the boot processor are changed
after Linux started to boot, before the initialsation of a secondary
processor, is not handled yet.
In this case, secondary processors are currently initialized by Linux
with MTRRs which the boot processor had very early, when mtrr_bp_init()
did run, but not with the MTRRs which the boot processor uses at the
time when that secondary processors is actually booted,
causing differing MTRR contents on the secondary processors.
Such situation happens on Acer Ferrari 1000 and 5000 notebooks where the
BIOS enables and sets AMD-specific IORR bits in the fixed-range MTRRs
of the boot processor when it transitions the system into ACPI mode.
The SMI handler of the BIOS does this in SMM, entered while Linux ACPI
code runs acpi_enable().
Other occasions where the SMI handler of the BIOS may change bits in
the MTRRs could occur as well. To initialize newly booted secodary
processors with the fixed-range MTRRs which the boot processor uses
at that time, this patch saves the fixed-range MTRRs of the boot
processor before new secondary processors are started. When the
secondary processors run their Linux initialisation code, their
fixed-range MTRRs will be updated with the saved fixed-range MTRRs.
If CONFIG_MTRR is not set, we define mtrr_save_state
as an empty statement because there is nothing to do.
Possible TODOs:
*) CPU-hotplugging outside of SMP suspend/resume is not yet tested
with this patch.
*) If, even in this case, an AP never runs i386/do_boot_cpu or x86_64/cpu_up,
then the calls to mtrr_save_state() could be replaced by calls to
mtrr_save_fixed_ranges(NULL) and mtrr_save_state() would not be
needed.
That would need either verification of the CPU-hotplug code or
at least a test on a >2 CPU machine.
*) The MTRRs of other running processors are not yet checked at this
time but it might be interesting to syncronize the MTTRs of all
processors before booting. That would be an incremental patch,
but of rather low priority since there is no machine known so
far which would require this.
AK: moved prototypes on x86-64 around to fix warnings
Signed-off-by: Bernhard Kaindl <bk@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Dave Jones <davej@codemonkey.org.uk>
In this current implementation which is used in other patches,
mtrr_save_fixed_ranges() accepts a dummy void pointer because
in the current implementation of one of these patches, this
function may be called from smp_call_function_single() which
requires that this function takes a void pointer argument.
This function calls get_fixed_ranges(), passing mtrr_state.fixed_ranges
which is the element of the static struct which stores our current
backup of the fixed-range MTRR values which all CPUs shall be
using.
Because mtrr_save_fixed_ranges calls get_fixed_ranges after
kernel initialisation time, __init needs to be removed from
the declaration of get_fixed_ranges().
If CONFIG_MTRR is not set, we define mtrr_save_fixed_ranges
as an empty statement because there is nothing to do.
AK: Moved prototypes for x86-64 around to fix warnings
Signed-off-by: Bernhard Kaindl <bk@suse.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Dave Jones <davej@codemonkey.org.uk>
Whether a region is below 1Mb is determined by its start rather than
its end.
This hunk got erroneously dropped from a previous patch.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mtrr: fix size_or_mask and size_and_mask
This fixes two bugs in /proc/mtrr interface:
o If physical address size crosses the 44 bit boundary
size_or_mask is evaluated wrong.
o size_and_mask limits width of physical base
address for an MTRR to be less than 44 bits.
TBD: later patch had one more change, but I think that was bogus.
TBD: need to double check
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
[akpm@osdl.org: sparc64 fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Until not so long ago, there were system log messages pointing to
inconsistent MTRR setup of the video frame buffer caused by the way vesafb
and X worked. While vesafb was fixed meanwhile, I believe fixing it there
only hides a shortcoming in the MTRR code itself, in that that code is not
symmetric with respect to the ordering of attempts to set up two (or more)
regions where one contains the other. In the current shape, it permits
only setting up sub-regions of pre-exisiting ones. The patch below makes
this symmetric.
While working on that I noticed a few more inconsistencies in that code,
namely
- use of 'unsigned int' for sizes in many, but not all places (the patch
is converting this to use 'unsigned long' everywhere, which specifically
might be necessary for x86-64 once a processor supporting more than 44
physical address bits would become available)
- the code to correct inconsistent settings during secondary processor
startup tried (if necessary) to correct, among other things, the value
in IA32_MTRR_DEF_TYPE, however the newly computed value would never get
used (i.e. stored in the respective MSR)
- the generic range validation code checked that the end of the
to-be-added range would be above 1MB; the value checked should have been
the start of the range
- when contained regions are detected, previously this was allowed only
when the old region was uncacheable; this can be symmetric (i.e. the new
region can also be uncacheable) and even further as per Intel's
documentation write-trough and write-back for either region is also
compatible with the respective opposite in the other
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Fix checks that failed to realize that values are 4-kB-unit-sized (note the
format strings in this same diff context which *do* realize the unit size,
via appended "000"!). Also fix an incorrect below-1MB area check (as
gathered from Jan Beulich's unapplied patch at
http://www.ussg.iu.edu/hypermail/linux/kernel/0411.1/1378.html ) Update
mtrr_add_page() docu to make 4-kB-sized calculation more obvious.
Given several further items mentioned in Jan's patch mail, all in all MTRR
code seems surprisingly buggy, for a surprisingly long period of time (many
years). Further work/investigation would be useful.
TBD Note that my patch is pretty much UNTESTED, since I can only verify that it
TBD successfully boots my machine, but I cannot test against actual buggy
TBD hardware which would require these (formerly broken) checks. Long -mm
TBD simmering would make sense, especially since these now-working checks might
TBD turn out to have adverse effects on unaffected hardware.
Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
The functions prepare_set and post_set in kernel/cpu/mtrr/generic.c wrap
the spinlock set_atomicity_lock: prepare_set returns with the lock held,
and post_set releases the lock without acquiring it. Add lock annotations
to these two functions so that sparse can check callers for lock pairing,
and so that sparse will not complain about these functions since they
intentionally use locks in this manner.
Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jens Axboe <axboe@suse.de>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Cc: Greg KH <greg@kroah.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arch: Use <linux/capability.h> where capable() is used.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I spotted 'main_lock' whilst grovelling through a vmlinux with objdump.
Even if it is static, it's a horrible name.
Signed-off-by: Dave Jones <davej@redhat.com>
They report 40bit, but only have 36bits of physical address space.
This caused problems with setting up the correct masks for MTRR.
CPUID workaround for steppings 0F33h(supporting x86) and 0F34h(supporting x86
and EM64T). Detail info can be found at:
http://download.intel.com/design/Xeon/specupdt/30240216.pdfhttp://download.intel.com/design/Pentium4/specupdt/30235221.pdf
Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Handle 32-bit mtrr ioctls in the mtrr driver instead of the ia32
compatability layer.
Signed-off-by: Brian Gerst <bgerst@didntduck.org>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix remaining bits of u32 vs. pm_message confusion. Should not break
anything.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There has been some discuss about solving the SMP MTRR suspend/resume
breakage, but I didn't find a patch for it. This is an intent for it. The
basic idea is moving mtrr initializing into cpu_identify for all APs (so it
works for cpu hotplug). For BP, restore_processor_state is responsible for
restoring MTRR.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Another large rollup of various patches from Adrian which make things static
where they were needlessly exported.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Enable write combining for server works LE rev > 6 per
http://www.ussg.iu.edu/hypermail/linux/kernel/0104.3/1007.html
Signed-Off-By: Lee Revell <rlrevell@joe-job.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to use the size_and_mask in set_mtrr_var_ranges(which is called
while programming MTRR's for AP's
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It doesn't make sense to only do this only for AMD K8.
This would support future CPUs with extended address spaces properly.
For i386 and x86-64
Cc: <davej@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
