While the modular aspect of the respective i386 patch doesn't apply to
x86-64 (as the top level page directory entry is shared between modules
and the base kernel), handlers registered with register_die_notifier()
are still under similar constraints for touching ioremap()ed or
vmalloc()ed memory. The likelihood of this problem becoming visible is
of course significantly lower, as the assigned virtual addresses would
have to cross a 2**39 byte boundary. This is because the callback gets
invoked
(a) in the page fault path before the top level page table propagation
gets carried out (hence a fault to propagate the top level page table
entry/entries mapping to module's code/data would nest infinitly) and
(b) in the NMI path, where nested faults must absolutely not happen,
since otherwise the IRET from the nested fault re-enables NMIs,
potentially resulting in nested NMI occurences.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The code waits for the GART to clear the TLB flush bit. Use cpu_relax
in this time to allow hypervisors to yield the CPU in this time.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The PM timer path through main_timer_handler doesn't need
the delay variable because it figures it out in a different way.
Don't try to read it from the PIT. With stopped PIT timer
it is even useless.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Minor cleanup to lend better for physical CPU hotplug.
Earlier way of using num_processors as index doesnt
fit if CPUs come and go. This makes the code little bit better
to read, and helps physical hotplug use the same functions as boot.
Reserving CPU0 for BSP is too late to be done in smp_prepare_boot_cpu().
Since logical assignments from MADT is already done via
setup_arch()->acpi_boot_init()->parse lapic
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Touching of the floating point state in a kernel debugger must be
NMI-safe, specifically math_state_restore() must be able to deal with
being called out of an NMI context. In order to do that reliably, the
context switch code must take care to not leave a window open where
the current task's TS_USEDFPU flag and CR0.TS could get out of sync.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
For consistency and to have only a single place of definition, replace
set_debug() uses with set_debugreg(), and eliminate the definition of
thj former.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
While AMD formally permits multi-byte execution breakpoints, Intel
disallows 8-byte as much as 2- or 4-byte ones.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix one place where the previous change of cpu_pda from being an array
to being a macro was not properly carried out.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It conflicts with the struct node in node.h
Actually the x86-64 version was there first, but ..
Suggested by Jan Beulich
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The upcomming gcc 4.2 got a new option -mtune=generic to tune
code for both common AMD and Intel CPUs. Use this option
when available for generic kernels.
On x86-64 it is used with CONFIG_GENERIC_CPU. On i386 it is
enabled with CONFIG_X86_GENERIC. It won't affect the base
line CPU support in any ways and also not the minimum supported CPU.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Memory >39bits has a different PUD.
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] New IA64 core/thread detection patch
[IA64] Increase max node count on SN platforms
[IA64] Increase max node count on SN platforms
[IA64] Increase max node count on SN platforms
[IA64] Increase max node count on SN platforms
[IA64] Tollhouse HP: IA64 arch changes
[IA64] cleanup dig_irq_init
[IA64] MCA recovery: kernel context recovery table
IA64: Use early_parm to handle mvec_name and nomca
[IA64] move patchlist and machvec into init section
[IA64] add init declaration - nolwsys
[IA64] add init declaration - gate page functions
[IA64] add init declaration to memory initialization functions
[IA64] add init declaration to cpu initialization functions
[IA64] add __init declaration to mca functions
[IA64] Ignore disabled Local SAPIC Affinity Structure in SRAT
[IA64] sn_check_intr: use ia64_get_irr()
[IA64] fix ia64 is_hugepage_only_range
* master.kernel.org:/pub/scm/linux/kernel/git/sam/kbuild: (46 commits)
kbuild: remove obsoleted scripts/reference_* files
kbuild: fix make help & make *pkg
kconfig: fix time ordering of writes to .kconfig.d and include/linux/autoconf.h
Kconfig: remove the CONFIG_CC_ALIGN_* options
kbuild: add -fverbose-asm to i386 Makefile
kbuild: clean-up genksyms
kbuild: Lindent genksyms.c
kbuild: fix genksyms build error
kbuild: in makefile.txt note that Makefile is preferred name for kbuild files
kbuild: replace PHONY with FORCE
kbuild: Fix bug in crc symbol generating of kernel and modules
kbuild: change kbuild to not rely on incorrect GNU make behavior
kbuild: when warning symbols exported twice now tell user this is the problem
kbuild: fix make dir/file.xx when asm symlink is missing
kbuild: in the section mismatch check try harder to find symbols
kbuild: fix section mismatch check for unwind on IA64
kbuild: kill false positives from section mismatch warnings for powerpc
kbuild: kill trailing whitespace in modpost & friends
kbuild: small update of allnoconfig description
kbuild: make namespace.pl CROSS_COMPILE happy
...
Trivial conflict in arch/ppc/boot/Makefile manually fixed up
Fix bug identified by Linus Torvalds <torvalds@osdl.org>: the `out'
instruction depends upon the state of memory_data[], so we need to tell gcc
that before executing it. (The opcode, not gcc).
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=5553
Thanks to Antonio Ospite <ospite@studenti.unina.it> for testing.
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Moved check for online cpu out of smp_prepare_cpu()
- Moved default declaration of smp_prepare_cpu() to kernel/cpu.c
- Removed lock_cpu_hotplug() from smp_prepare_cpu() to around it, since
its called from cpu_up() as well now.
- Removed clearing from cpu_present_map during cpu_offline as it breaks
using cpu_up() directly during a subsequent online operation.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds missing bits of collie (sharp sl-5500) PCMCIA support and
MFD support.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The Kconfig text for CONFIG_DEBUG_SLAB and CONFIG_DEBUG_PAGEALLOC have always
seemed a bit confusing. Change them to:
CONFIG_DEBUG_SLAB: "Debug slab memory allocations"
CONFIG_DEBUG_PAGEALLOC: "Debug page memory allocations"
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some BIOSes do not always set CF on error before return from int13. The
patch adds additional check for status being zero (AH == 0).
Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
MODULE_PARM was actually breaking: recent gcc version optimize them out as
unused. It's time to replace the last users, which are generally in the
most unloved drivers anyway.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
DEBUG_PAGEALLOC is not compatible with hugetlb page support. That debug
option turns off PSE. Once it is turned off in CR4, the cpu will ignore
pse bit in the pmd and causing infinite page-not- present faults.
So disable DEBUG_PAGEALLOC if the user selected hugetlbfs.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make CONFIG_HOTPLUG_CPU depend on !X86_PC, so we need to turn on either
CONFIG_GENERICARCH, CONFIG_BIGSMP or any other subarch except X86_PC when
CONFIG_HOTPLUG_CPU=y
With 2.6.15+ kernels when CONFIG_HOTPLUG_CPU is turned on we switch to
bigsmp mode for sending IPI's and ioapic configurations that caused the
following error message.
>> More than 8 CPUs detected and CONFIG_X86_PC cannot handle it.
>> Use CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.
Originally bigsmp was added just to handle >8 cpus, but now with hotplug
cpu support we need to use bigsmp mode (why? see below), that cause the
above error message even if there were less than 8 cpus in the system.
The message is bogus, but we are cannot use logical flat mode due to issues
with broadcast IPI can confuse a CPU just comming up. We use flat physical
mode just like x86_64 case. More details on why bigsmp now uses flat
physical mode (vs. cluster mode) in following link.
http://marc.theaimsgroup.com/?l=linux-kernel&m=113261865814107&w=2
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
alarm() calls the kernel with an unsigend int timeout in seconds. The
value is stored in the tv_sec field of a struct timeval to setup the
itimer. The tv_sec field of struct timeval is of type long, which causes
the tv_sec value to be negative on 32 bit machines if seconds > INT_MAX.
Before the hrtimer merge (pre 2.6.16) such a negative value was converted
to the maximum jiffies timeout by the timeval_to_jiffies conversion. It's
not clear whether this was intended or just happened to be done by the
timeval_to_jiffies code.
hrtimers expect a timeval in canonical form and treat a negative timeout as
already expired. This breaks the legitimate usage of alarm() with a
timeout value > INT_MAX seconds.
For 32 bit machines it is therefor necessary to limit the internal seconds
value to avoid API breakage. Instead of doing this in all implementations
of sys_alarm the duplicated sys_alarm code is moved into a common function
in itimer.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Attached patch fixes invalid pointer arithmetic in DMI code to make onboard
device discovery working again.
akpm: bug has been present since dmi_find_device() was added in 2.6.14.
Affects ipmi only (I think) - the symptoms weren't described.
akpm: changed to use pointer arithmetic rather than open-coded sizeof.
Signed-off-by: Andrey Panin <pazke@donpac.ru>
Cc: Corey Minyard <minyard@acm.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
IPF SDM 2.2 changes definition of PAL_LOGICAL_TO_PHYSICAL to add
proc_number=-1 to get core/thread mapping info on the running processer.
Based on this change, we had better to update existing core/thread
detection in IA64 kernel correspondingly. The attached patch implements
this change. It simplifies detection code and eliminates potential race
condition. It also runs a bit faster and has better scalability especially
when cores and threads number grows up in one package.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Node number are kept in the cpu_to_node_map which is
currently defined as u8. Change to u16 to accomodate
larger node numbers.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Add support in IA64 acpi for platforms that support more than
256 nodes. Currently, ACPI is limited to 256 nodes because the
proximity domain number is 8-bits.
Long term, we expect to use ACPI3.0 to support >256 nodes.
This patch is an interim solution that works with platforms
that pass the high order bits of the proximity domain in
"reserved" fields of the ACPI tables. This code is enabled
ONLY on SN platforms.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Add a configuration option to allow the maximum
number of nodes to be configurable for GENERIC or SN
kernels.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
arch/ia64/sn and include/asm-ia64/sn changes required to support Tollhouse
system PCI hotplug, fixes the ia64_sn_sysctl_ioboard_get call, and introduces
the PRF_HOTPLUG_SUPPORT feature bit.
Signed-off-by: Prarit Bhargava <prarit@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
dig_irq_init is equivalent to machvec_noop, no need to define
another empty function.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Memory errors encountered by user applications may surface
when the CPU is running in kernel context. The current code
will not attempt recovery if the MCA surfaces in kernel
context (privilage mode 0). This patch adds a check for cases
where the user initiated the load that surfaces in kernel
interrupt code.
An example is a user process lauching a load from memory
and the data in memory had bad ECC. Before the bad data
gets to the CPU register, and interrupt comes in. The
code jumps to the IVT interrupt entry point and begins
execution in kernel context. The process of saving the
user registers (SAVE_REST) causes the bad data to be loaded
into a CPU register, triggering the MCA. The MCA surfaces in
kernel context, even though the load was initiated from
user context.
As suggested by David and Tony, this patch uses an exception
table like approach, puting the tagged recovery addresses in
a searchable table. One difference from the exception table
is that MCAs do not surface in precise places (such as with
a TLB miss), so instead of tagging specific instructions,
address ranges are registers. A single macro is used to do
the tagging, with the input parameter being the label
of the starting address and the macro being the ending
address. This limits clutter in the code.
This patch only tags one spot, the interrupt ivt entry.
Testing showed that spot to be a "heavy hitter" with
MCAs surfacing while saving user registers. Other spots
can be added as needed by adding a single macro.
Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: Tony Luck <tony.luck@intel.com>
We need set_page_dirty() to return true if it actually transitioned the page
from a clean to dirty state. This wasn't right in a couple of places. Do a
kernel-wide audit, fix things up.
This leaves open the possibility of returning a negative errno from
set_page_dirty() sometime in the future. But we don't do that at present.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove all trailing tabs and spaces. No other changes.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
include/linux/platform.h contained nothing that was actually used except
the default_idle() prototype, and is therefore removed by this patch.
This patch does the following with the platform specific default_idle()
functions on different architectures:
- remove the unused function:
- parisc
- sparc64
- make the needlessly global function static:
- arm
- h8300
- m68k
- m68knommu
- s390
- v850
- x86_64
- add a prototype in asm/system.h:
- cris
- i386
- ia64
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Patrick Mochel <mochel@digitalimplant.org>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Convert all kmalloc + memset sequences in arch/s390 to kzalloc usage.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Include connector config in the s390 arch Kconfig to get support for
connectors.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Retry starting of new cpu if sigp restart returns condition code 2 (busy).
Signed-off-by: Michael Ryan <ryan@funsoft.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Set permissoin of /proc/sys/vm/cmm_* files to 0644.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use common code parser for early parameters instead of our own.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
While working on these patch set, I found several possible cleanup on x86-64
and ia64.
akpm: I stole this from Andi's queue.
Not only does it clean up bitops. It also unrelatedly changes the prototype
of pci_mmcfg_init() and removes its arch_initcall(). It seems that the wrong
two patches got joined together, but this is the one which has been tested.
This patch fixes the current x86_64 build error (the pci_mmcfg_init()
declaration in arch/i386/pci/pci.h disagrees with the definition in
arch/x86_64/pci/mmconfig.c)
This also means that x86_64's pci_mmcfg_init() gets called in the same (new)
manner as x86's: from arch/i386/pci/init.c:pci_access_init(), rather than via
initcall.
The bitops cleanups came along for free.
All this worked OK in -mm testing (since 2.6.16-rc4-mm1) because x86_64 was
tested with both patches applied.
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Con Kolivas <kernel@kolivas.org>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I screwed up this conversion - we should be iterating across online CPUs, not
possible ones.
Spotted by Joe Perches <joe@perches.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Todo items:
- IRQ_INPROGRESS flag - use sparc64 irq buckets, or generic irq_desc?
- sun4d
- re-indent large chunks of sun4m_smp.c
- some places assume sequential cpu numbering (i.e. 0,1 instead of 0,2)
Last I checked (with 2.6.14), random programs segfault with dual
HyperSPARC. And with SuperSPARC II's, it seems stable but will
eventually die from a write lock error (wrong lock owner or something).
I haven't tried the HyperSPARC + highmem combination recently, so that
may still be a problem.
Signed-off-by: David S. Miller <davem@davemloft.net>
"In some cases, especially on modern laptops with a lot of PCI and cardbus
bridges, we're unable to assign correct secondary/subordinate bus numbers
to all cardbus bridges due to BIOS limitations unless we are using
"pci=assign-busses" boot option." -- Ivan Kokshaysky (from a patch comment)
Without it, Cardbus cards inserted are never seen by PCI because the parent
PCI-PCI Bridge of the Cardbus bridge will not pass and translate Type 1 PCI
configuration cycles correctly and the system will fail to find and
initialise the PCI devices in the system.
Reference: PCI-PCI Bridges: PCI Configuration Cycles and PCI Bus Numbering:
http://www.science.unitn.it/~fiorella/guidelinux/tlk/node72.html
The reason for this is that:
``All PCI busses located behind a PCI-PCI bridge must reside between the
secondary bus number and the subordinate bus number (inclusive).''
"pci=assign-busses" makes pcibios_assign_all_busses return 1 and this
turns on PCI renumbering during PCI probing.
Alan suggested to use DMI automatically set assign-busses on problem systems.
The only question for me was where to put it. I put it directly before
scanning PCI bus into pcibios_scan_root() because it's called from legacy,
acpi and numa and so it can be one place for all systems and configurations
which may need it.
AMD64 Laptops are also affected and fixed by assign-busses, and the code is
also incuded from arch/x86_64/pci/ that place will also work for x86_64
kernels, I only ifdef'-ed the x86-only Laptop in this example.
Affected and known or assumed to be fixed with it are (found by googling):
* ASUS Z71V and L3s
* Samsung X20
* Compaq R3140us and all Compaq R3000 series laptops with TI1620 Controller,
also Compaq R4000 series (from a kernel.org bugreport)
* HP zv5000z (AMD64 3700+, known that fixup_parent_subordinate_busnr fixes it)
* HP zv5200z
* IBM ThinkPad 240
* An IBM ThinkPad (1.8 GHz Pentium M) debugged by Pavel Machek
gives the correspondig message which detects the possible problem.
* MSI S260 / Medion SIM 2100 MD 95600
The patch also expands the "try pci=assign-busses" warning so testers will
help us to update the DMI table.
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On Tue, 21 Feb 2006, Ivan Kokshaysky wrote:
> There are two bogus entries in the BIOS memory map table which are
> conflicting with a prefetchable memory range of the AGP bridge:
>
> BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved)
> BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
>
> 0000:00:02.0 PCI bridge: Silicon Integrated Systems [SiS] Virtual PCI-to-PCI bridge (AGP) (prog-if 00 [Normal decode])
> Flags: bus master, fast devsel, latency 0
> Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
> I/O behind bridge: 0000c000-0000cfff
> Memory behind bridge: e7e00000-e7efffff
> Prefetchable memory behind bridge: fec00000-ffcfffff
> ^^^^^^^^^^^^^^^^^
Yes. However, it's pretty clear that the e820 entries are there for a
reason. Probably they are a hack by the BIOS maintainers to keep Windows
from stomping/moving that region, exactly because they want to keep the
bridge where it is (or, it's actually for the BIOS itself - the BIOS
tables are a horrid mess, and BIOS engineers are pretty hacky people:
they'll add random entries to make their own broken algorithms do the
"right thing").
> Starting from 2.6.13, kernel tries to resolve that sort of conflicts,
> so that prefetch window of the bridge and the framebuffer memory behind
> it get moved to 0x10000000.
I think we could (and probably should) solve this another way: consider
the ACPI "reserved regions" from the e820 map exactly the same way that we
do other ACPI hints - they should restrict _new_ allocations, but not
impact stuff we figure out on our own.
Basically, right now we assign _unassigned_ resources at "fs_initcall"
time. If we were to add in the e820 "reserved region" stuff before that
(but after we've done PCI discovery), we'd probably do the right thing.
Right now we do the e820 reserved regions very early indeed: we call
"register_memory()" from setup_arch(). We could move at least part of it
(the part that registers the resources) down a bit.
Here's a test-patch. I'm not saying we should absolutely do this, but it
might be interesting to try...
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: <bjk@luxsci.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
