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170 commits

Author SHA1 Message Date
H. Peter Anvin
f026cfa82f Revert "x86-64/efi: Use EFI to deal with platform wall clock"
This reverts commit bacef661ac.

This commit has been found to cause serious regressions on a number of
ASUS machines at the least.  We probably need to provide a 1:1 map in
addition to the EFI virtual memory map in order for this to work.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Reported-and-bisected-by: Jérôme Carretero <cJ-ko@zougloub.eu>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120805172903.5f8bb24c@zougloub.eu
2012-08-14 09:58:25 -07:00
Linus Torvalds
0a2fe19ccc Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pul x86/efi changes from Ingo Molnar:
 "This tree adds an EFI bootloader handover protocol, which, once
  supported on the bootloader side, will make bootup faster and might
  result in simpler bootloaders.

  The other change activates the EFI wall clock time accessors on x86-64
  as well, instead of the legacy RTC readout."

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: Handover Protocol
  x86-64/efi: Use EFI to deal with platform wall clock
2012-07-26 13:13:25 -07:00
Wanpeng Li
9efc31b81d x86/mm: Fix some kernel-doc warnings
Fix kernel-doc warnings in arch/x86/mm/ioremap.c and
arch/x86/mm/pageattr.c, just like this one:

  Warning(arch/x86/mm/ioremap.c:204):
     No description found for parameter 'phys_addr'
  Warning(arch/x86/mm/ioremap.c:204):
     Excess function parameter 'offset' description in 'ioremap_nocache'

Signed-off-by: Wanpeng Li <liwp@linux.vnet.ibm.com>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Cc: Wanpeng Li <liwp.linux@gmail.com>
Link: http://lkml.kernel.org/r/1339296652-2935-1-git-send-email-liwp.linux@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-11 10:54:45 +02:00
Jan Beulich
bacef661ac x86-64/efi: Use EFI to deal with platform wall clock
Other than ix86, x86-64 on EFI so far didn't set the
{g,s}et_wallclock accessors to the EFI routines, thus
incorrectly using raw RTC accesses instead.

Simply removing the #ifdef around the respective code isn't
enough, however: While so far early get-time calls were done in
physical mode, this doesn't work properly for x86-64, as virtual
addresses would still need to be set up for all runtime regions
(which wasn't the case on the system I have access to), so
instead the patch moves the call to efi_enter_virtual_mode()
ahead (which in turn allows to drop all code related to calling
efi-get-time in physical mode).

Additionally the earlier calling of efi_set_executable()
requires the CPA code to cope, i.e. during early boot it must be
avoided to call cpa_flush_array(), as the first thing this
function does is a BUG_ON(irqs_disabled()).

Also make the two EFI functions in question here static -
they're not being referenced elsewhere.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Matt Fleming <matt.fleming@intel.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4FBFBF5F020000780008637F@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06 11:48:05 +02:00
Linus Torvalds
d0b9706c20 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/numa: Add constraints check for nid parameters
  mm, x86: Remove debug_pagealloc_enabled
  x86/mm: Initialize high mem before free_all_bootmem()
  arch/x86/kernel/e820.c: quiet sparse noise about plain integer as NULL pointer
  arch/x86/kernel/e820.c: Eliminate bubble sort from sanitize_e820_map()
  x86: Fix mmap random address range
  x86, mm: Unify zone_sizes_init()
  x86, mm: Prepare zone_sizes_init() for unification
  x86, mm: Use max_low_pfn for ZONE_NORMAL on 64-bit
  x86, mm: Wrap ZONE_DMA32 with CONFIG_ZONE_DMA32
  x86, mm: Use max_pfn instead of highend_pfn
  x86, mm: Move zone init from paging_init() on 64-bit
  x86, mm: Use MAX_DMA_PFN for ZONE_DMA on 32-bit
2012-01-11 19:12:10 -08:00
Stanislaw Gruszka
54c29c635a mm, x86: Remove debug_pagealloc_enabled
When (no)bootmem finish operation, it pass pages to buddy
allocator. Since debug_pagealloc_enabled is not set, we will do
not protect pages, what is not what we want with
CONFIG_DEBUG_PAGEALLOC=y.

To fix remove debug_pagealloc_enabled. That variable was
introduced by commit 12d6f21e "x86: do not PSE on
CONFIG_DEBUG_PAGEALLOC=y" to get more CPA (change page
attribude) code testing. But currently we have CONFIG_CPA_DEBUG,
which test CPA.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1322582711-14571-1-git-send-email-sgruszka@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 09:24:07 +01:00
H Hartley Sweeten
2d070eff6b arch/x86/mm/pageattr.c: Quiet sparse noise; local functions should be static
Local functions should be marked static.  This also quiets the
following sparse noise:

  warning: symbol '_set_memory_array' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: hartleys@visionengravers.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-05 17:11:05 +01:00
Lucas De Marchi
0d2eb44f63 x86: Fix common misspellings
They were generated by 'codespell' and then manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: trivial@kernel.org
LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 10:39:30 +01:00
Andrea Arcangeli
a79e53d856 x86/mm: Fix pgd_lock deadlock
It's forbidden to take the page_table_lock with the irq disabled
or if there's contention the IPIs (for tlb flushes) sent with
the page_table_lock held will never run leading to a deadlock.

Nobody takes the pgd_lock from irq context so the _irqsave can be
removed.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <201102162345.p1GNjMjm021738@imap1.linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-10 09:41:57 +01:00
Matthieu CASTET
f12d3d04e8 x86, nx: Don't force pages RW when setting NX bits
Xen want page table pages read only.

But the initial page table (from head_*.S) live in .data or .bss.

That was broken by 64edc8ed5f.  There is
absolutely no reason to force these pages RW after they have already
been marked RO.

Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-02-02 16:02:36 -08:00
Matthieu Castet
5bd5a45266 x86: Add NX protection for kernel data
This patch expands functionality of CONFIG_DEBUG_RODATA to set main
(static) kernel data area as NX.

The following steps are taken to achieve this:

 1. Linker script is adjusted so .text always starts and ends on a page bound
 2. Linker script is adjusted so .rodata always start and end on a page boundary
 3. NX is set for all pages from _etext through _end in mark_rodata_ro.
 4. free_init_pages() sets released memory NX in arch/x86/mm/init.c
 5. bios rom is set to x when pcibios is used.

The results of patch application may be observed in the diff of kernel page
table dumps:

pcibios:

 -- data_nx_pt_before.txt       2009-10-13 07:48:59.000000000 -0400
 ++ data_nx_pt_after.txt        2009-10-13 07:26:46.000000000 -0400
  0x00000000-0xc0000000           3G                           pmd
  ---[ Kernel Mapping ]---
 -0xc0000000-0xc0100000           1M     RW             GLB x  pte
 +0xc0000000-0xc00a0000         640K     RW             GLB NX pte
 +0xc00a0000-0xc0100000         384K     RW             GLB x  pte
 -0xc0100000-0xc03d7000        2908K     ro             GLB x  pte
 +0xc0100000-0xc0318000        2144K     ro             GLB x  pte
 +0xc0318000-0xc03d7000         764K     ro             GLB NX pte
 -0xc03d7000-0xc0600000        2212K     RW             GLB x  pte
 +0xc03d7000-0xc0600000        2212K     RW             GLB NX pte
  0xc0600000-0xf7a00000         884M     RW         PSE GLB NX pmd
  0xf7a00000-0xf7bfe000        2040K     RW             GLB NX pte
  0xf7bfe000-0xf7c00000           8K                           pte

No pcibios:

 -- data_nx_pt_before.txt       2009-10-13 07:48:59.000000000 -0400
 ++ data_nx_pt_after.txt        2009-10-13 07:26:46.000000000 -0400
  0x00000000-0xc0000000           3G                           pmd
  ---[ Kernel Mapping ]---
 -0xc0000000-0xc0100000           1M     RW             GLB x  pte
 +0xc0000000-0xc0100000           1M     RW             GLB NX pte
 -0xc0100000-0xc03d7000        2908K     ro             GLB x  pte
 +0xc0100000-0xc0318000        2144K     ro             GLB x  pte
 +0xc0318000-0xc03d7000         764K     ro             GLB NX pte
 -0xc03d7000-0xc0600000        2212K     RW             GLB x  pte
 +0xc03d7000-0xc0600000        2212K     RW             GLB NX pte
  0xc0600000-0xf7a00000         884M     RW         PSE GLB NX pmd
  0xf7a00000-0xf7bfe000        2040K     RW             GLB NX pte
  0xf7bfe000-0xf7c00000           8K                           pte

The patch has been originally developed for Linux 2.6.34-rc2 x86 by
Siarhei Liakh <sliakh.lkml@gmail.com> and Xuxian Jiang <jiang@cs.ncsu.edu>.

 -v1:  initial patch for 2.6.30
 -v2:  patch for 2.6.31-rc7
 -v3:  moved all code into arch/x86, adjusted credits
 -v4:  fixed ifdef, removed credits from CREDITS
 -v5:  fixed an address calculation bug in mark_nxdata_nx()
 -v6:  added acked-by and PT dump diff to commit log
 -v7:  minor adjustments for -tip
 -v8:  rework with the merge of "Set first MB as RW+NX"

Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com>
Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu>
Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: James Morris <jmorris@namei.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dave Jones <davej@redhat.com>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4CE2F82E.60601@free.fr>
[ minor cleanliness edits ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18 12:52:04 +01:00
matthieu castet
64edc8ed5f x86: Fix improper large page preservation
This patch fixes a bug in try_preserve_large_page() which may
result in improper large page preservation and improper
application of page attributes to the memory area outside of the
original change request.

More specifically, the problem manifests itself when set_memory_*()
is called for several pages at the beginning of the large page and
try_preserve_large_page() erroneously concludes that the change can
be applied to whole large page.

The fix consists of 3 parts:

  1. Addition of "required" protection attributes in
     static_protections(), so .data and .bss can be guaranteed to
     stay "RW"

  2. static_protections() is now called for every small
     page within large page to determine compatibility of new
     protection attributes (instead of just small pages within the
     requested range).

  3. Large page can be preserved only if attribute change is
     large-page-aligned and covers whole large page.

 -v1: Try_preserve_large_page() patch for Linux 2.6.34-rc2
 -v2: Replaced pfn check with address check for kernel rw-data

Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com>
Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu>
Reviewed-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: James Morris <jmorris@namei.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dave Jones <davej@redhat.com>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4CE2F7F3.8030809@free.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18 12:52:04 +01:00
Dave Airlie
c2b41276da Merge branch 'drm-ttm-pool' into drm-core-next
* drm-ttm-pool:
  drm/ttm: using kmalloc/kfree requires including slab.h
  drm/ttm: include linux/seq_file.h for seq_printf
  drm/ttm: Add sysfs interface to control pool allocator.
  drm/ttm: Use set_pages_array_wc instead of set_memory_wc.
  arch/x86: Add array variants for setting memory to wc caching.
  drm/nouveau: Add ttm page pool debugfs file.
  drm/radeon/kms: Add ttm page pool debugfs file.
  drm/ttm: Add debugfs output entry to pool allocator.
  drm/ttm: add pool wc/uc page allocator V3
2010-04-20 13:12:28 +10:00
Pauli Nieminen
4f64625412 arch/x86: Add array variants for setting memory to wc caching.
Setting single memory pages at a time to wc takes a lot time in cache flush. To
reduce number of cache flush set_pages_array_wc and set_memory_array_wc can be
used to set multiple pages to WC with single cache flush.

This improves allocation performance for wc cached pages in drm/ttm.

CC: Suresh Siddha <suresh.b.siddha@intel.com>
CC: Venkatesh Pallipadi <venkatesh.pallipadi@gmail.com>
Signed-off-by: Pauli Nieminen <suokkos@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-06 11:36:06 +10:00
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
Suresh Siddha
281ff33b7c x86_64, cpa: Don't work hard in preserving kernel 2M mappings when using 4K already
We currently enforce the !RW mapping for the kernel mapping that maps
holes between different text, rodata and data sections. However, kernel
identity mappings will have different RWX permissions to the pages mapping to
text and to the pages padding (which are freed) the text, rodata sections.
Hence kernel identity mappings will be broken to smaller pages. For 64-bit,
kernel text and kernel identity mappings are different, so we can enable
protection checks that come with CONFIG_DEBUG_RODATA, as well as retain 2MB
large page mappings for kernel text.

Konrad reported a boot failure with the Linux Xen paravirt guest because of
this. In this paravirt guest case, the kernel text mapping and the kernel
identity mapping share the same page-table pages. Thus forcing the !RW mapping
for some of the kernel mappings also cause the kernel identity mappings to be
read-only resulting in the boot failure. Linux Xen paravirt guest also
uses 4k mappings and don't use 2M mapping.

Fix this issue and retain large page performance advantage for native kernels
by not working hard and not enforcing !RW for the kernel text mapping,
if the current mapping is already using small page mapping.

Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1266522700.2909.34.camel@sbs-t61.sc.intel.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: stable@kernel.org	[2.6.32, 2.6.33]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-22 15:09:31 -08:00
H. Peter Anvin
583140afb9 x86, pageattr: Make set_memory_(x|nx) aware of NX support
Make set_memory_x/set_memory_nx directly aware of if NX is supported
in the system or not, rather than requiring that every caller assesses
that support independently.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tim Starling <tstarling@wikimedia.org>
Cc: Hannes Eder <hannes@hanneseder.net>
LKML-Reference: <1258154897-6770-4-git-send-email-hpa@zytor.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
2009-11-16 13:44:58 -08:00
Suresh Siddha
55ca3cc174 x86_64, ftrace: Make ftrace use kernel identity mapping to modify code
On x86_64, kernel text mappings are mapped read-only with
CONFIG_DEBUG_RODATA. So use the kernel identity mapping instead
of the kernel text mapping to modify the kernel text.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20091029024821.080941108@sbs-t61.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-02 17:16:36 +01:00
Suresh Siddha
502f660466 x86, cpa: Fix kernel text RO checks in static_protection()
Steven Rostedt reported that we are unconditionally making the
kernel text mapping as read-only. i.e., if someone does cpa() to
the kernel text area for setting/clearing any page table
attribute, we unconditionally clear the read-write attribute for
the kernel text mapping that is set at compile time.

We should delay (to forbid the write attribute) and enforce only
after the kernel has mapped the text as read-only.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20091029024820.996634347@sbs-t61.sc.intel.com>
[ marked kernel_set_to_readonly as __read_mostly ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-02 17:16:35 +01:00
Steven Rostedt
883242dd0e tracing: allow to change permissions for text with dynamic ftrace enabled
The commit 74e081797b
x86-64: align RODATA kernel section to 2MB with CONFIG_DEBUG_RODATA
prevents text sections from becoming read/write using set_memory_rw.

The dynamic ftrace changes all text pages to read/write just before
converting the calls to tracing to nops, and vice versa.

I orginally just added a flag to allow this transaction when ftrace
did the change, but I also found that when the CPA testing was running
it would remove the read/write as well, and ftrace does not do the text
conversion on boot up, and the CPA changes caused the dynamic tracer
to fail on self tests.

The current solution I have is to simply not to prevent
change_page_attr from setting the RW bit for kernel text pages.

Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-10-27 13:15:11 -04:00
Suresh Siddha
74e081797b x86-64: align RODATA kernel section to 2MB with CONFIG_DEBUG_RODATA
CONFIG_DEBUG_RODATA chops the large pages spanning boundaries of kernel
text/rodata/data to small 4KB pages as they are mapped with different
attributes (text as RO, RODATA as RO and NX etc).

On x86_64, preserve the large page mappings for kernel text/rodata/data
boundaries when CONFIG_DEBUG_RODATA is enabled. This is done by allowing the
RODATA section to be hugepage aligned and having same RWX attributes
for the 2MB page boundaries

Extra Memory pages padding the sections will be freed during the end of the boot
and the kernel identity mappings will have different RWX permissions compared to
the kernel text mappings.

Kernel identity mappings to these physical pages will be mapped with smaller
pages but large page mappings are still retained for kernel text,rodata,data
mappings.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20091014220254.190119924@sbs-t61.sc.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-10-20 14:46:00 +09:00
Linus Torvalds
94e0fb086f Merge branch 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: (57 commits)
  drm/i915: Handle ERESTARTSYS during page fault
  drm/i915: Warn before mmaping a purgeable buffer.
  drm/i915: Track purged state.
  drm/i915: Remove eviction debug spam
  drm/i915: Immediately discard any backing storage for uneeded objects
  drm/i915: Do not mis-classify clean objects as purgeable
  drm/i915: Whitespace correction for madv
  drm/i915: BUG_ON page refleak during unbind
  drm/i915: Search harder for a reusable object
  drm/i915: Clean up evict from list.
  drm/i915: Add tracepoints
  drm/i915: framebuffer compression for GM45+
  drm/i915: split display functions by chip type
  drm/i915: Skip the sanity checks if the current relocation is valid
  drm/i915: Check that the relocation points to within the target
  drm/i915: correct FBC update when pipe base update occurs
  drm/i915: blacklist Acer AspireOne lid status
  ACPI: make ACPI button funcs no-ops if not built in
  drm/i915: prevent FIFO calculation overflows on 32 bits with high dotclocks
  drm/i915: intel_display.c handle latency variable efficiently
  ...

Fix up trivial conflicts in drivers/gpu/drm/i915/{i915_dma.c|i915_drv.h}
2009-09-24 10:30:41 -07:00
Linus Torvalds
ada3fa1505 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
  powerpc64: convert to dynamic percpu allocator
  sparc64: use embedding percpu first chunk allocator
  percpu: kill lpage first chunk allocator
  x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
  percpu: update embedding first chunk allocator to handle sparse units
  percpu: use group information to allocate vmap areas sparsely
  vmalloc: implement pcpu_get_vm_areas()
  vmalloc: separate out insert_vmalloc_vm()
  percpu: add chunk->base_addr
  percpu: add pcpu_unit_offsets[]
  percpu: introduce pcpu_alloc_info and pcpu_group_info
  percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
  percpu: add @align to pcpu_fc_alloc_fn_t
  percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
  percpu: drop @static_size from first chunk allocators
  percpu: generalize first chunk allocator selection
  percpu: build first chunk allocators selectively
  percpu: rename 4k first chunk allocator to page
  percpu: improve boot messages
  percpu: fix pcpu_reclaim() locking
  ...

Fix trivial conflict as by Tejun Heo in kernel/sched.c
2009-09-15 09:39:44 -07:00
Eric Anholt
e517a5e970 agp/intel: Fix the pre-9xx chipset flush.
Ever since we enabled GEM, the pre-9xx chipsets (particularly 865) have had
serious stability issues.  Back in May a wbinvd was added to the DRM to
work around much of the problem.  Some failure remained -- easily visible
by dragging a window around on an X -retro desktop, or by looking at bugzilla.

The chipset flush was on the right track -- hitting the right amount of
memory, and it appears to be the only way to flush on these chipsets, but the
flush page was mapped uncached.  As a result, the writes trying to clear the
writeback cache ended up bypassing the cache, and not flushing anything!  The
wbinvd would flush out other writeback data and often cause the data we wanted
to get flushed, but not always.  By removing the setting of the page to UC
and instead just clflushing the data we write to try to flush it, we get the
desired behavior with no wbinvd.

This exports clflush_cache_range(), which was laying around and happened to
basically match the code I was otherwise going to copy from the DRM.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org>
Cc: stable@kernel.org
2009-09-11 11:39:23 -07:00
Jack Steiner
fa526d0d64 x86, pat: Fix cacheflush address in change_page_attr_set_clr()
Fix address passed to cpa_flush_range() when changing page
attributes from WB to UC. The address (*addr) is
modified by __change_page_attr_set_clr(). The result is that
the pages being flushed start at the _end_ of the changed range
instead of the beginning.

This should be considered for 2.6.30-stable and 2.6.31-stable.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Stable team <stable@kernel.org>
2009-09-09 14:05:24 -07:00
Tejun Heo
e933a73f48 percpu: kill lpage first chunk allocator
With x86 converted to embedding allocator, lpage doesn't have any user
left.  Kill it along with cpa handling code.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
2009-08-14 15:00:53 +09:00
Tejun Heo
384be2b18a Merge branch 'percpu-for-linus' into percpu-for-next
Conflicts:
	arch/sparc/kernel/smp_64.c
	arch/x86/kernel/cpu/perf_counter.c
	arch/x86/kernel/setup_percpu.c
	drivers/cpufreq/cpufreq_ondemand.c
	mm/percpu.c

Conflicts in core and arch percpu codes are mostly from commit
ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many
num_possible_cpus() with nr_cpu_ids.  As for-next branch has moved all
the first chunk allocators into mm/percpu.c, the changes are moved
from arch code to mm/percpu.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-08-14 14:45:31 +09:00
Thomas Hellstrom
8523acfe40 x86: Fix CPA memtype reserving in the set_pages_array*() cases
The code was incorrectly reserving memtypes using the page
virtual address instead of the physical address. Furthermore,
the code was not ignoring highmem pages as it ought to.

( upstream does not pass in highmem pages yet - but upcoming
  graphics code will do it and there's no reason to not handle
  this properly in the CPA APIs.)

Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=13884

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: <stable@kernel.org>
Cc: dri-devel@lists.sourceforge.net
Cc: venkatesh.pallipadi@intel.com
LKML-Reference: <1249284345-7654-1-git-send-email-thellstrom@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-03 19:36:09 +02:00
Pallipadi, Venkatesh
bdc6340f4e x86, pat: Fix set_memory_wc related corruption
Changeset 3869c4aa18
that went in after 2.6.30-rc1 was a seemingly small change to _set_memory_wc()
to make it complaint with SDM requirements. But, introduced a nasty bug, which
can result in crash and/or strange corruptions when set_memory_wc is used.
One such crash reported here
http://lkml.org/lkml/2009/7/30/94

Actually, that changeset introduced two bugs.
* change_page_attr_set() takes &addr as first argument and can the addr value
  might have changed on return, even for single page change_page_attr_set()
  call. That will make the second change_page_attr_set() in this routine
  operate on unrelated addr, that can eventually cause strange corruptions
  and bad page state crash.
* The second change_page_attr_set() call, before setting _PAGE_CACHE_WC, should
  clear the earlier _PAGE_CACHE_UC_MINUS, as otherwise cache attribute will not
  be WC (will be UC instead).

The patch below fixes both these problems. Sending a single patch to fix both
the problems, as the change is to the same line of code. The change to have a
addr_copy is not very clean. But, it is simpler than making more changes
through various routines in pageattr.c.

A huge thanks to Jerome for reporting this problem and providing a simple test
case that helped us root cause the problem.

Reported-by: Jerome Glisse <glisse@freedesktop.org>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090730214319.GA1889@linux-os.sc.intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-07-30 17:48:34 -07:00
Tejun Heo
8c4bfc6e88 x86,percpu: generalize lpage first chunk allocator
Generalize and move x86 setup_pcpu_lpage() into
pcpu_lpage_first_chunk().  setup_pcpu_lpage() now is a simple wrapper
around the generalized version.  Other than taking size parameters and
using arch supplied callbacks to allocate/free/map memory,
pcpu_lpage_first_chunk() is identical to the original implementation.

This simplifies arch code and will help converting more archs to
dynamic percpu allocator.

While at it, factor out pcpu_calc_fc_sizes() which is common to
pcpu_embed_first_chunk() and pcpu_lpage_first_chunk().

[ Impact: code reorganization and generalization ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-07-04 08:10:59 +09:00
Tejun Heo
e59a1bb2fd x86: fix pageattr handling for lpage percpu allocator and re-enable it
lpage allocator aliases a PMD page for each cpu and returns whatever
is unused to the page allocator.  When the pageattr of the recycled
pages are changed, this makes the two aliases point to the overlapping
regions with different attributes which isn't allowed and known to
cause subtle data corruption in certain cases.

This can be handled in simliar manner to the x86_64 highmap alias.
pageattr code should detect if the target pages have PMD alias and
split the PMD alias and synchronize the attributes.

pcpur allocator is updated to keep the allocated PMD pages map sorted
in ascending address order and provide pcpu_lpage_remapped() function
which binary searches the array to determine whether the given address
is aliased and if so to which address.  pageattr is updated to use
pcpu_lpage_remapped() to detect the PMD alias and split it up as
necessary from cpa_process_alias().

Jan Beulich spotted the original problem and incorrect usage of vaddr
instead of laddr for lookup.

With this, lpage percpu allocator should work correctly.  Re-enable
it.

[ Impact: fix subtle lpage pageattr bug and re-enable lpage ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-22 11:56:24 +09:00
Tejun Heo
992f4c1c2c x86: reorganize cpa_process_alias()
Reorganize cpa_process_alias() so that new alias condition can be
added easily.

Jan Beulich spotted problem in the original cleanup thread which
incorrectly assumed the two existing conditions were mutially
exclusive.

[ Impact: code reorganization ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-22 11:56:24 +09:00
Vegard Nossum
9e730237c2 kmemcheck: don't track page tables
As these are allocated using the page allocator, we need to pass
__GFP_NOTRACK before we add page allocator support to kmemcheck.

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2009-06-15 12:40:11 +02:00
Linus Torvalds
be15f9d63b Merge branch 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits)
  xen: cache cr0 value to avoid trap'n'emulate for read_cr0
  xen/x86-64: clean up warnings about IST-using traps
  xen/x86-64: fix breakpoints and hardware watchpoints
  xen: reserve Xen start_info rather than e820 reserving
  xen: add FIX_TEXT_POKE to fixmap
  lguest: update lazy mmu changes to match lguest's use of kvm hypercalls
  xen: honour VCPU availability on boot
  xen: add "capabilities" file
  xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet
  xen/sys/hypervisor: change writable_pt to features
  xen: add /sys/hypervisor support
  xen/xenbus: export xenbus_dev_changed
  xen: use device model for suspending xenbus devices
  xen: remove suspend_cancel hook
  xen/dev-evtchn: clean up locking in evtchn
  xen: export ioctl headers to userspace
  xen: add /dev/xen/evtchn driver
  xen: add irq_from_evtchn
  xen: clean up gate trap/interrupt constants
  xen: set _PAGE_NX in __supported_pte_mask before pagetable construction
  ...
2009-06-10 16:16:27 -07:00
Pallipadi, Venkatesh
2171787be2 x86: avoid back to back on_each_cpu in cpa_flush_array
Cleanup cpa_flush_array() to avoid back to back on_each_cpu() calls.

[ Impact: optimizes fix 0af48f42df ]

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-26 13:12:12 -07:00
venkatesh.pallipadi@intel.com
0af48f42df x86: cpa_flush_array wbinvd should be done on all CPUs
cpa_flush_array seems to prefer wbinvd() over clflush at 4M threshold.
clflush needs to be done on only one CPU as per instruction definition.
wbinvd() however, should be done on all CPUs.

[ Impact: fix missing flush which could cause data corruption ]

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-22 13:33:59 -07:00
venkatesh.pallipadi@intel.com
0b827537e3 x86: bugfix wbinvd() model check instead of family check
wbinvd is supported on all CPUs 486 or later. But,
pageattr.c is checking x86_model >= 4 before wbinvd(), which looks like
an oversight bug. It was first introduced at one place by changeset
d7c8f21a8c and got copied over to second
place in the same file later.

[ Impact: fix missing cache flush on early-model CPUs, potential data corruption ]

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-22 13:33:27 -07:00
Ingo Molnar
f066a15533 Merge branch 'x86/urgent' into x86/xen
Conflicts:
	arch/frv/include/asm/pgtable.h
	arch/x86/include/asm/required-features.h
	arch/x86/xen/mmu.c

Merge reason: x86/xen was on a .29 base still, move it to a fresher
              branch and pick up Xen fixes as well, plus resolve
              conflicts

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-08 10:50:00 +02:00
venkatesh.pallipadi@intel.com
3869c4aa18 x86, PAT: Changing memtype to WC ensuring no WB alias
As per SDM, there should not be any aliasing of a WC with any cacheable
type across CPUs. That is if one CPU is changing the identity map
memtype to _WC, no other CPU at the time of this change should not have a
TLB for this page that carries a WB attribute. SDM suggests to make the
page not present. But for that we will have to handle any page faults
that can potentially happen due to these pages being not present.

Other way to deal with this without having any WB mapping is to change
the page first to UC and then to WC. This ensures that we meet the SDM
requirement of no cacheable alais to WC page. This also has same or
lower overhead than marking the page not present and making it present
later.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.797481000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-10 13:55:47 +02:00
venkatesh.pallipadi@intel.com
9fa3ab390a x86, PAT: Handle faults cleanly in set_memory_ APIs
Handle faults and do proper cleanups in set_memory_*() functions. In
some cases, these functions were not doing proper free on failure paths.

With the changes to tracking memtype of RAM pages in struct page instead
of pat list, we do not need the changes in commits c5e147. This patch
reverts that change.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.653222000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-10 13:55:47 +02:00
venkatesh.pallipadi@intel.com
a5593e0b32 x86, PAT: Change order of cpa and free in set_memory_wb
To be free of aliasing due to races, set_memory_* interfaces should
follow ordering of reserving, changing memtype to UC/WC, changing
memtype back to WB followed by free.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.512280000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-10 13:55:46 +02:00
Jeremy Fitzhardinge
38f4b8c0da Merge commit 'origin/master' into for-linus/xen/master
* commit 'origin/master': (4825 commits)
  Fix build errors due to CONFIG_BRANCH_TRACER=y
  parport: Use the PCI IRQ if offered
  tty: jsm cleanups
  Adjust path to gpio headers
  KGDB_SERIAL_CONSOLE check for module
  Change KCONFIG name
  tty: Blackin CTS/RTS
  Change hardware flow control from poll to interrupt driven
  Add support for the MAX3100 SPI UART.
  lanana: assign a device name and numbering for MAX3100
  serqt: initial clean up pass for tty side
  tty: Use the generic RS485 ioctl on CRIS
  tty: Correct inline types for tty_driver_kref_get()
  splice: fix deadlock in splicing to file
  nilfs2: support nanosecond timestamp
  nilfs2: introduce secondary super block
  nilfs2: simplify handling of active state of segments
  nilfs2: mark minor flag for checkpoint created by internal operation
  nilfs2: clean up sketch file
  nilfs2: super block operations fix endian bug
  ...

Conflicts:
	arch/x86/include/asm/thread_info.h
	arch/x86/lguest/boot.c
	drivers/xen/manage.c
2009-04-07 13:34:16 -07:00
Jeremy Fitzhardinge
b8bcfe997e x86/paravirt: remove lazy mode in interrupts
Impact: simplification, robustness

Make paravirt_lazy_mode() always return PARAVIRT_LAZY_NONE
when in an interrupt.  This prevents interrupt code from
accidentally inheriting an outer lazy state, and instead
does everything synchronously.  Outer batched operations
are left deferred.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
2009-03-29 23:35:38 -07:00
Ingo Molnar
6e15cf0486 Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2
Conflicts:
	arch/parisc/kernel/irq.c
	arch/x86/include/asm/fixmap_64.h
	arch/x86/include/asm/setup.h
	kernel/irq/handle.c

Semantic merge:
        arch/x86/include/asm/fixmap.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-27 17:28:43 +01:00
venkatesh.pallipadi@intel.com
0f3507555f x86, CPA: Add set_pages_arrayuc and set_pages_array_wb
Add new interfaces:

  set_pages_array_uc()
  set_pages_array_wb()

that can be used change the page attribute for a bunch of pages with
flush etc done once at the end of all the changes. These interfaces
are similar to existing set_memory_array_uc() and set_memory_array_wc().

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: arjan@infradead.org
Cc: eric@anholt.net
Cc: airlied@redhat.com
LKML-Reference: <20090319215358.901545000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-20 10:34:49 +01:00
venkatesh.pallipadi@intel.com
9ae2847591 x86, PAT: Add support for struct page pointer array in cpa set_clr
Add struct page array pointer to cpa struct and CPA_PAGES_ARRAY.

With that we can add change_page_attr_set_clr() a parameter to pass
struct page array pointer and that can be handled by the underlying
cpa code.

cpa_flush_array() is also changed to support both addr array or
struct page pointer array, depending on the flag.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: arjan@infradead.org
Cc: eric@anholt.net
Cc: airlied@redhat.com
LKML-Reference: <20090319215358.758513000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-20 10:34:48 +01:00
venkatesh.pallipadi@intel.com
728c951887 x86, CPA: Add a flag parameter to cpa set_clr()
Change change_page_attr_set_clr() array parameter to a flag. This helps
following patches which adds an interface to change attr to uc/wb over a
set of pages referred by struct page.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: arjan@infradead.org
Cc: eric@anholt.net
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: airlied@redhat.com
LKML-Reference: <20090319215358.611346000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-20 10:34:47 +01:00
Jeremy Fitzhardinge
93dbda7cbc x86: add brk allocation for very, very early allocations
Impact: new interface

Add a brk()-like allocator which effectively extends the bss in order
to allow very early code to do dynamic allocations.  This is better than
using statically allocated arrays for data in subsystems which may never
get used.

The space for brk allocations is in the bss ELF segment, so that the
space is mapped properly by the code which maps the kernel, and so
that bootloaders keep the space free rather than putting a ramdisk or
something into it.

The bss itself, delimited by __bss_stop, ends before the brk area
(__brk_base to __brk_limit).  The kernel text, data and bss is reserved
up to __bss_stop.

Any brk-allocated data is reserved separately just before the kernel
pagetable is built, as that code allocates from unreserved spaces
in the e820 map, potentially allocating from any unused brk memory.
Ultimately any unused memory in the brk area is used in the general
kernel memory pool.

Initially the brk space is set to 1MB, which is probably much larger
than any user needs (the largest current user is i386 head_32.S's code
to build the pagetables to map the kernel, which can get fairly large
with a big kernel image and no PSE support).  So long as the system
has sufficient memory for the bootloader to reserve the kernel+1MB brk,
there are no bad effects resulting from an over-large brk.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14 15:37:14 -07:00
Ingo Molnar
a98fe7f342 Merge branches 'x86/asm', 'x86/debug', 'x86/mm', 'x86/setup', 'x86/urgent' and 'linus' into x86/core 2009-03-12 11:50:15 +01:00
Ingo Molnar
211b3d03c7 x86: work around Fedora-11 x86-32 kernel failures on Intel Atom CPUs
Impact: work around boot crash

Work around Intel Atom erratum AAH41 (probabilistically) - it's triggering
in the field.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11 18:22:03 +01:00