* Use new set_cpus_allowed_ptr() function added by previous patch,
which instead of passing the "newly allowed cpus" cpumask_t arg
by value, pass it by pointer:
-int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
+int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)
* Cleanup uses of CPU_MASK_ALL.
* Collapse other NR_CPUS changes to arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
Use pointers to cpumask_t arguments whenever possible.
Depends on:
[sched-devel]: sched: add new set_cpus_allowed_ptr function
Cc: Len Brown <len.brown@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Replace usages of CPU_MASK_NONE, CPU_MASK_ALL, NODE_MASK_NONE,
NODE_MASK_ALL to reduce stack requirements for large NR_CPUS
and MAXNODES counts.
* In some cases, the cpumask variable was initialized but then overwritten
with another value. This is the case for changes like this:
- cpumask_t oldmask = CPU_MASK_ALL;
+ cpumask_t oldmask;
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Change the following static arrays sized by NR_CPUS to
per_cpu data variables:
_cpuid4_info *cpuid4_info[NR_CPUS];
_index_kobject *index_kobject[NR_CPUS];
kobject * cache_kobject[NR_CPUS];
* Remove the local NR_CPUS array with a kmalloc'd region in
show_shared_cpu_map().
Also some minor complaints from checkpatch.pl fixed.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch changes smpboot.c so that it can start slave cpus running
in UV non-unique apicid mode. The SIPI must be sent using a UV-specific
mechanism.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The code in pci-dma_{32,64}.c are now sufficiently
close to each other. We merge them in pci-dma.c.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
if the device hasn't provided a mask, abort allocation.
Note that we're using a fallback device now, so it does not cover
the case of a NULL device: just drivers passing NULL masks around.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Just return our allocation if we don't have an mmu. For i386, where this patch
is being applied, we never have. So our goal is just to have the code to look like
x86_64's.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The claim is that i386 does it. Just it does not.
So remove it.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use the same gfp masks for x86_64 and i386.
It involves using HIGHMEM or DMA32 where necessary, for the sake
of code compatibility, (no real effect), and using the NORETRY
mask for i386.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch puts in the code to retry allocation in case it fails. By its
own, it does not make much sense but making the code look like x86_64.
But later patches in this series will make we try to allocate from
zones other than DMA first, which will possibly fail.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If we fail, we'll loop into the allocation again,
and then allocate in the DMA zone.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We can use a fallback dev for cases of a NULL device being passed (mostly ISA)
This comes from x86_64 implementation.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We can do it here to, in the same way x86_64 does.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
virt_to_bus() is deprecated according to the docs, and moreover,
won't return the right thing in i386 if we're dealing with high memory mappings.
So we make our allocation function return a page, and then use page_address() (for
virtual addr) and page_to_phys() (for physical addr) instead.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We call unmap_single, if available.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
It goes to pci-dma.c, and is removed from the arch-specific files.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
i386 implements the declare coherent memory API, and x86_64 does not
it is reflected in pieces of dma_alloc_coherent and dma_free_coherent.
Those pieces are isolated in separate functions, that are declared
as empty macros in x86_64. This way we can make the code the same.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
They are placed in an ifdef, since they are i386 specific
the structure definition goes to dma-mapping.h.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
we merge the iommu initialization parameters in pci-dma.c
Nice thing, that both architectures at least recognize the same
parameters.
usedac i386 parameter is marked for deprecation
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The code for both arches are very similar, so this patch merge them.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
via_no_dac provides a fixup that is the same for both
architectures. Move it to pci-dma.c.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch moves the bootmem functions, that are largely
x86_64-specific into pci-dma.c. The code goes inside an ifdef.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
initcalls that triggers the various possibiities for
dma subsys are moved to pci-dma.c.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
merge pci-base_32.c and pci-nommu_64.c into pci-nommu.c
Their code were made the same, so now they can be merged.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move dma_ops structure definition to pci-dma.c, where it
belongs.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This is done to get the code closer to x86_64.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In the very same way i386 do, we use WARN_ON functions
in map_simple and map_sg.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
To make the code usable in i386, where we have high memory mappings,
we drop te virt_to_bus(sg_virt()) construction in favour of sg_phys.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds flush_write_buffers() in some functions of pci-nommu_64.c
They are added anywhere i386 would also have it. This is not a problem
for x86_64, since flush_rite_buffers() an nop for it.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch implements mapping_error for pci-nommu_64.c.
It takes care to keep the same compatible behaviour it already
had. Although this file is not (yet) used for i386, we introduce
the i386 version here. Again, care is taken, even at the expense of
an ifdef, to keep the same behaviour inconditionally.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This functions are now called conditionally on their
existence in the struct. So just delete them, instead
of keeping an empty implementation.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch introduces pci-dma.c, a common file for pci dma
between i386 and x86_64. As a start, dma_set_mask() is the same
between architectures, and is placed there.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
ERROR: "dma_supported" [drivers/ssb/ssb.ko] undefined!
ERROR: "dma_set_mask" [drivers/scsi/qla2xxx/qla2xxx.ko] undefined!
ERROR: "dma_set_mask" [drivers/scsi/aic7xxx/aic7xxx.ko] undefined!
ERROR: "dma_set_mask" [drivers/scsi/aic7xxx/aic79xx.ko] undefined!
ERROR: "dma_supported" [drivers/net/pcnet32.ko] undefined!
ERROR: "dma_supported" [drivers/media/video/saa7134/saa7134.ko] undefined!
ERROR: "dma_set_mask" [drivers/media/video/meye.ko] undefined!
ERROR: "dma_supported" [drivers/media/video/cx88/cx8802.ko] undefined!
ERROR: "dma_supported" [drivers/media/video/cx88/cx8800.ko] undefined!
ERROR: "dma_supported" [drivers/media/video/cx88/cx88-alsa.ko] undefined!
ERROR: "dma_supported" [drivers/media/video/cx23885/cx23885.ko] undefined!
They just need to be exported like on x86_64.
dma_supported() and dma_set_mask() were previously inlined,
but are now moved to pci-dma_32.c.
Since they're used by various drivers, they need to be
exported.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We provide a map_error function in pci-base_32.c to make
sure i386 keeps with the same behaviour it used to.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
It's initially 0, since we don't expect any DMA there.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This is the way x86_64 does, so this make them equal. They have
to be extern now in the header, and the extern definition is moved to
the common dma-mapping.h header.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
the old i386 implementation is moved to pci-base_32.c
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
i386 base does not need it, so it gets an empty function.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
That's already the name of the game for x86_64. For i386,
we add a pci-base_32.c, that will hold the default operations.
The function call itself goes through dma-mapping.h , the common
header
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
a system with 256 GB of RAM, when NUMA is disabled crashes the
following way:
Your BIOS doesn't leave a aperture memory hole
Please enable the IOMMU option in the BIOS setup
This costs you 64 MB of RAM
Cannot allocate aperture memory hole (ffff8101c0000000,65536K)
Kernel panic - not syncing: Not enough memory for aperture
Pid: 0, comm: swapper Not tainted 2.6.25-rc4-x86-latest.git #33
Call Trace:
[<ffffffff84037c62>] panic+0xb2/0x190
[<ffffffff840381fc>] ? release_console_sem+0x7c/0x250
[<ffffffff847b1628>] ? __alloc_bootmem_nopanic+0x48/0x90
[<ffffffff847b0ac9>] ? free_bootmem+0x29/0x50
[<ffffffff847ac1f7>] gart_iommu_hole_init+0x5e7/0x680
[<ffffffff847b255b>] ? alloc_large_system_hash+0x16b/0x310
[<ffffffff84506a2f>] ? _etext+0x0/0x1
[<ffffffff847a2e8c>] pci_iommu_alloc+0x1c/0x40
[<ffffffff847ac795>] mem_init+0x45/0x1a0
[<ffffffff8479ff35>] start_kernel+0x295/0x380
[<ffffffff8479f1c2>] _sinittext+0x1c2/0x230
the root cause is : memmap PMD is too big,
[ffffe200e0600000-ffffe200e07fffff] PMD ->ffff81383c000000 on node 0
almost near 4G..., and vmemmap_alloc_block will use up the ram under 4G.
solution will be:
1. make memmap allocation get memory above 4G...
2. reserve some dma32 range early before we try to set up memmap for all.
and release that before pci_iommu_alloc, so gart or swiotlb could get some
range under 4g limit for sure.
the patch is using method 2.
because method1 may need more code to handle SPARSEMEM and SPASEMEM_VMEMMAP
will get
Your BIOS doesn't leave a aperture memory hole
Please enable the IOMMU option in the BIOS setup
This costs you 64 MB of RAM
Mapping aperture over 65536 KB of RAM @ 4000000
Memory: 264245736k/268959744k available (8484k kernel code, 4187464k reserved, 4004k data, 724k init)
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Only allocate the FPU area when the application actually uses FPU, i.e., in the
first lazy FPU trap. This could save memory for non-fpu using apps.
for example: on my system after boot, there are around 300 processes, with
only 17 using FPU.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Split the FPU save area from the task struct. This allows easy migration
of FPU context, and it's generally cleaner. It also allows the following
two optimizations:
1) only allocate when the application actually uses FPU, so in the first
lazy FPU trap. This could save memory for non-fpu using apps. Next patch
does this lazy allocation.
2) allocate the right size for the actual cpu rather than 512 bytes always.
Patches enabling xsave/xrstor support (coming shortly) will take advantage
of this.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
this function doesnt just 'find' the max_pfn - it also has
other side-effects such as registering sparse memory maps.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We already catch most of the TSC problems by sanity checks, but there
is a subtle bug which has been in the code forever. This can cause
time jumps in the range of hours.
This was reported in:
http://lkml.org/lkml/2007/8/23/96
and
http://lkml.org/lkml/2008/3/31/23
I was able to reproduce the problem with a gettimeofday loop test on a
dual core and a quad core machine which both have sychronized
TSCs. The TSCs seems not to be perfectly in sync though, but the
kernel is not able to detect the slight delta in the sync check. Still
there exists an extremly small window where this delta can be observed
with a real big time jump. So far I was only able to reproduce this
with the vsyscall gettimeofday implementation, but in theory this
might be observable with the syscall based version as well.
CPU 0 updates the clock source variables under xtime/vyscall lock and
CPU1, where the TSC is slighty behind CPU0, is reading the time right
after the seqlock was unlocked.
The clocksource reference data was updated with the TSC from CPU0 and
the value which is read from TSC on CPU1 is less than the reference
data. This results in a huge delta value due to the unsigned
subtraction of the TSC value and the reference value. This algorithm
can not be changed due to the support of wrapping clock sources like
pm timer.
The huge delta is converted to nanoseconds and added to xtime, which
is then observable by the caller. The next gettimeofday call on CPU1
will show the correct time again as now the TSC has advanced above the
reference value.
To prevent this TSC specific wreckage we need to compare the TSC value
against the reference value and return the latter when it is larger
than the actual TSC value.
I pondered to mark the TSC unstable when the readout is smaller than
the reference value, but this would render an otherwise good and fast
clocksource unusable without a real good reason.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch implements the PR_GET_TSC and PR_SET_TSC prctl()
commands on the x86 platform (both 32 and 64 bit.) These
commands control the ability to read the timestamp counter
from userspace (the RDTSC instruction.)
While the RDTSC instuction is a useful profiling tool,
it is also the source of some non-determinism in ring-3.
For deterministic replay applications it is useful to be
able to trap and emulate (and record the outcome of) this
instruction.
This patch uses code earlier used to disable the timestamp
counter for the SECCOMP framework. A side-effect of this
patch is that the SECCOMP environment will now also disable
the timestamp counter on x86_64 due to the addition of the
TIF_NOTSC define on this platform.
The code which enables/disables the RDTSC instruction during
context switches is in the __switch_to_xtra function, which
already handles other unusual conditions, so normal
performance should not have to suffer from this change.
Signed-off-by: Erik Bosman <ejbosman@cs.vu.nl>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This annotates NMI functions with notrace. Some tracers may be able
to live with this, but some cannot. The safest is to turn it off,
it's not particularly interesting anyway.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
- noexec32 is on by default for years already
- add noexec32 to kernel-parameters and fix noexec typo in there
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
fix section mismatch warnings which occurs on my x86_64 box while compiling
linux-next-20080410:
Warning messages:
WARNING: arch/x86/kernel/built-in.o(.text+0x7bc2): Section mismatch in reference from the function bad_addr() to the
variable .init.data:early_res
The function bad_addr() references
the variable __initdata early_res.
This is often because bad_addr lacks a __initdata
annotation or the annotation of early_res is wrong.
WARNING: arch/x86/kernel/built-in.o(.text+0x7c3b): Section mismatch in reference from the function bad_addr_size() to
the variable .init.data:early_res
The function bad_addr_size() references
the variable __initdata early_res.
This is often because bad_addr_size lacks a __initdata
annotation or the annotation of early_res is wrong.
Signed-off-by: Jacek Luczak <luczak.jacek@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
I've made a small investigation about vm86.h inclusion rules and it
looks like everything is more or less ok.
Files that rely on asm/vm86.h symbols are:
- kprobes.c
- process_32.c
- signal_32.c
- traps_32.c
- vm86_32.c
File process_32.c includes vm86.h explicitly. We can remove that
include and it won't break anything.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Remove old comments that include the old arch/i386 directory.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
ramdisk is reserved via reserve_early in x86_64_start_kernel,
later early_res_to_bootmem() will convert to reservation in bootmem.
so don't need to reserve that again.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Make x86 EFI code works when EFI_PAGE_SHIFT != PAGE_SHIFT. The
memrage_efi_to_native() provided in this patch can be used on other
EFI platform such as IA64 too.
This patch has been tested on Intel x86_64 platform with EFI 64/32
firmware.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
None of these files use any of the functionality promised by
asm/semaphore.h. It's possible that they rely on it dragging in some
unrelated header file, but I can't build all these files, so we'll have
fix any build failures as they come up.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
TF_MASK is no longer defined, use X86_EFLAGS_TF.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kgdb core fixes:
- Check to see that mm->mmap_cache is not null before calling
flush_cache_range(), else on arch=ARM it will cause a fatal
fault.
- Breakpoints should only be restored if they are in the BP_ACTIVE
state.
- Fix a typo in comments to "kgdb_register_io_module"
x86 kgdb fixes:
- Fix the x86 arch handler such that on a kill or detach that the
appropriate cleanup on the single stepping flags gets run.
- Add in the DIE_NMIWATCHDOG call for x86_64
- Touch the nmi watchdog before returning the system to normal
operation after performing any kind of kgdb operation, else
the possibility exists to trigger the watchdog.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add HW breakpoints into the arch specific portion of x86 kgdb. In the
current x86 kernel.org kernels HW breakpoints are changed out in lazy
fashion because there is no infrastructure around changing them when
changing to a kernel task or entering the kernel mode via a system
call. This lazy approach means that if a user process uses HW
breakpoints the kgdb will loose out. This is an acceptable trade off
because the developer debugging the kernel is assumed to know what is
going on system wide and would be aware of this trade off.
There is a minor bug fix to the kgdb core so as to correctly call the
hw breakpoint functions with a valid value from the enum.
There is also a minor change to the x86_64 startup code when using
early HW breakpoints. When the debugger is connected, the cpu startup
code must not zero out the HW breakpoint registers or you cannot hit
the breakpoints you are interested in, in the first place.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes the hang regression with kgdb when the NMI interrupt
comes in while the master core is returning from an exception.
Adjust the NMI logic such that KGDB will not stop NMI exceptions from
occurring by in general returning NOTIFY_DONE. It is not possible to
distinguish the debug NMI sync vs the normal NMI apic interrupt so
kgdb needs to catch the unknown NMI if it the debugger was previously
active on one of the cpus.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
simplified and streamlined kgdb support on x86, both 32-bit and 64-bit,
based on patch from:
Subject: kgdb: core-lite
From: Jason Wessel <jason.wessel@windriver.com>
[ and countless other authors - see the patch for details. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Move wakeup code to .c, so that video mode setting code can be shared
between boot and wakeup. Remove nasty assembly code in 64-bit case by
re-using trampoline code. Stack setup was fixed to clear high 16bits
of %esp, maybe that fixes some machines.
.c code sharing and morse code was done H. Peter Anvin, Sam Ravnborg
reviewed kbuild related stuff, and it seems okay to him. Rafael did
some cleanups.
[rjw:
* Made the patch stop breaking compilation on x86-32
* Added arch/x86/kernel/acpi/sleep.h
* Got rid of compiler warnings in arch/x86/kernel/acpi/sleep.c
* Fixed 32-bit compilation on x86-64 systems
* Added include/asm-x86/trampoline.h and fixed the non-SMP
compilation on 64-bit x86
* Removed arch/x86/kernel/acpi/sleep_32.c which was not used
* Fixed some breakage caused by the integration of smpboot.c done
under us in the meantime]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
this patch fixes section mismatch warnings (on x86_64 host) in setup_trampoline(),
which was referencing __initdata variables trampoline_data and trampoline_end.
Warning messages:
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x2b6a): Section mismatch in reference from the function setup_trampoline()
to the variable .init.data:trampoline_data
The function __cpuinit setup_trampoline() references
a variable __initdata trampoline_data.
If trampoline_data is only used by setup_trampoline then
annotate trampoline_data with a matching annotation.
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x2b71): Section mismatch in reference from the function setup_trampoline()
to the variable .init.data:trampoline_end
The function __cpuinit setup_trampoline() references
a variable __initdata trampoline_end.
If trampoline_end is only used by setup_trampoline then
annotate trampoline_end with a matching annotation.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes mismatch warnings in smp_checks() (in arch/x86/kernel/smpboot.c):
WARNING: arch/x86/kernel/built-in.o(.text+0x11922): Section mismatch in reference from the function smp_checks()
to the variable .cpuinit.data:smp_b_stepping
The function smp_checks() references
the variable __cpuinitdata smp_b_stepping.
This is often because smp_checks lacks a __cpuinitdata
annotation or the annotation of smp_b_stepping is wrong.
Signed-off-by: Jacek Luczak <luczak.jacek@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
> > Make sure that we clear the "shutdown status flag" in the CMOS
> > register after each CPU is brought up. This fixes a problem where the
> > "shutdown status flag" may remain set when a CPU is brought up after
> > booting.
>
> btw., what problem does this result in, exactly?
The shutdown status flag set to "0xA", corresponds to "JMP double word
request without INT init".
This JMP at reboot time is at an unintended location. And results in
Triple faults in our case.
Though this error at reboot can be safely ignored in a VM environment,
am not sure what the effect would be on a physical system. May be it
will result in a triple fault and an eventual hardware reset thus
masking this BUG in the kernel.
This fix just makes sure that we reset that status flag after
initialization is done.
Fix paranoia about using BIOS quickboot mechanism.
Make sure that we clear the "shutdown status flag" in the CMOS register
after each CPU is brought up. This fixes a problem where the "shutdown
status flag" may remain set when a CPU is brought up after booting.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Arai <arai@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use cpumask_of_cpu() rather than the pair of cpus_clear() and cpu_set().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
No need to clear the memory allocated by alloc_bootmem().
It is already filled with zero.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove duplicate code by using ioapic_read_entry() and ioapic_write_entry()
in io_apic_{32,64}.c
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If one can find an ack pending pin, there is no need to check
the rest of them.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We should call for kfree if only we really need it.
Though it's safe to call kfree with NULL pointer passed
in this code we've already tested the pointer and can
eliminate the call
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Yinghai Lu pointed out a bug in the previous patches,
fix double-shift of apicid.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cleanup references to the early cpu maps for the non-SMP configuration
and remove some functions called for SMP configurations only.
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
UV supports really big systems. So big, in fact, that the APICID register
does not contain enough bits to contain an APICID that is unique across all
cpus.
The UV BIOS supports 3 APICID modes:
- legacy mode. This mode uses the old APIC mode where
APICID is in bits [31:24] of the APICID register.
- x2apic mode. This mode is whitebox-compatible. APICIDs
are unique across all cpus. Standard x2apic APIC operations
(Intel-defined) can be used for IPIs. The node identifier
fits within the Intel-defined portion of the APICID register.
- x2apic-uv mode. In this mode, the APICIDs on each node have
unique IDs, but IDs on different node are not unique. For example,
if each mode has 32 cpus, the APICIDs on each node might be
0 - 31. Every node has the same set of IDs.
The UV hub is used to route IPIs/interrupts to the correct node.
Traditional APIC operations WILL NOT WORK.
In x2apic-uv mode, the ACPI tables all contain a full unique ID (note:
exact bit layout still changing but the following is close):
nnnnnnnnnnlc0cch
n = unique node number
l = socket number on board
c = core
h = hyperthread
Only the "lc0cch" bits are written to the APICID register. The remaining bits are
supplied by having the get_apic_id() function "OR" the extra bits into the value
read from the APICID register. (Hmmm.. why not keep the ENTIRE APICID register
in per-cpu data....)
The x2apic-uv mode is recognized by the MADT table containing:
oem_id = "SGI"
oem_table_id = "UV-X"
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add kernel support for new ACPI "sapic" tables that contain 16-bit APICIDs.
This patch simply adds parsing of an optional SAPIC table if present.
Otherwise, the traditional local APIC table is used.
Note: the SAPIC table is not a new ACPI table - it exists on other architectures
but is not currently recognized by x86_64.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Increase the number of bits in an apicid from 8 to 32.
By default, MP_processor_info() gets the APICID from the
mpc_config_processor structure. However, this structure limits
the size of APICID to 8 bits. This patch allows the caller of
MP_processor_info() to optionally pass a larger APICID that will
be used instead of the one in the mpc_config_processor struct.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add functions that can be used to determine if an x86_64
system is a SGI "UV" system. UV systems come in 3 types and
are identified by the OEM ID in the MADT.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Introduce a function to read the local APIC_ID.
This change is in preparation for additional changes to
the APICID functions that will come in a later patch.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch renames VM_MASK to X86_VM_MASK (which
in turn defined as alias to X86_EFLAGS_VM) to better
distinguish from virtual memory flags. We can't just
use X86_EFLAGS_VM instead because it is also used
for conditional compilation
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The memory resource is also used for main memory, and we need it to
allocate physical addresses for memory hotplug. Knobbling io space is
enough to get the job done anyway.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Report when microcode was successfully updated. It used to be there but
now with DEBUG unset it becomes very silent. Also some cosmetic fixes.
Signed-off-by: Ben Castricum <lk08@bencastricum.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Upcoming 64 bit processors from Centaur can use sysenter.
Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Jesse Ahrens <jahrens@centtech.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
By including processor-flags.h we are allowed to use predefined
macroses instead of keeping own ones
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On AMD SMM protected memory is part of the address map, but handled
internally like an MTRR. That leads to large pages getting split
internally which has some performance implications. Check for the
AMD TSEG MSR and split the large page mapping on that area
explicitely if it is part of the direct mapping.
There is also SMM ASEG, but it is in the first 1MB and already covered by
the earlier split first page patch.
Idea for this came from an earlier patch by Andreas Herrmann
On a RevF dual Socket Opteron system kernbench shows a clear
improvement from this:
(together with the earlier patches in this series, especially the
split first 2MB patch)
[lower is better]
no split stddev split stddev delta
Elapsed Time 87.146 (0.727516) 84.296 (1.09098) -3.2%
User Time 274.537 (4.05226) 273.692 (3.34344) -0.3%
System Time 34.907 (0.42492) 34.508 (0.26832) -1.1%
Percent CPU 322.5 (38.3007) 326.5 (44.5128) +1.2%
=> About 3.2% improvement in elapsed time for kernbench.
With GB pages on AMD Fam1h the impact of splitting is much higher of course,
since it would split two full GB pages (together with the first
1MB split patch) instead of two 2MB pages. I could not benchmark
a clear difference in kernbench on gbpages, so I kept it disabled
for that case
That was only limited benchmarking of course, so if someone
was interested in running more tests for the gbpages case
that could be revisited (contributions welcome)
I didn't bother implementing this for 32bit because it is very
unlikely the 32bit lowmem mapping overlaps into the TSEG near 4GB
and the 2MB low split is already handled for both.
[ mingo@elte.hu: do it on gbpages kernels too, there's no clear reason
why it shouldnt help there. ]
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: andreas.herrmann3@amd.com
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Intel recommends to not use large pages for the first 1MB
of the physical memory because there are fixed size MTRRs there
which cause splitups in the TLBs.
On AMD doing so is also a good idea.
The implementation is a little different between 32bit and 64bit.
On 32bit I just taught the initial page table set up about this
because it was very simple to do. This also has the advantage
that the risk of a prefetch ever seeing the page even
if it only exists for a short time is minimized.
On 64bit that is not quite possible, so use set_memory_4k() a little
later (in check_bugs) instead.
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: andreas.herrmann3@amd.com
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When end_pfn is not aligned to 2MB (or 1GB) then the kernel might
map more memory than end_pfn. Account this in max_pfn_mapped.
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: andreas.herrmann3@amd.com
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently they are in .text.head because the rest of head_64.S.
.text.head is not removed as init data, but the early exception handlers
should be because they are not needed after early boot of the BP.
So move them over.
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The early exception handlers are currently set up using a macro
recursion. There is only one user left. Replace the macro with a
standard loop in place.
Noop patch, just a cleanup.
[ tglx@linutronix.de: simplified ]
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
All of early setup runs with interrupts disabled, so there is no
need to set up early exception handlers for vectors >= 32
This saves some minor text size.
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Ingo Molnar (mingo@elte.hu) wrote:
>
> * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
>
> > The shadow vmap for DEBUG_RODATA kernel text modification uses
> > virt_to_page to get the pages from the pointer address.
> >
> > However, I think vmalloc_to_page would be required in case the page is
> > used for modules.
> >
> > Since only the core kernel text is marked read-only, use
> > kernel_text_address() to make sure we only shadow map the core kernel
> > text, not modules.
>
> actually, i think we should mark module text readonly too.
>
Yes, but in the meantime, the x86 tree would need this patch to make
kprobes work correctly on modules.
I suspect that without this fix, with the enhanced hotplug and kprobes
patch, kprobes will use text_poke to insert breakpoints in modules
(vmalloced pages used), which will map the wrong pages and corrupt
random kernel locations instead of updating the correct page.
Work that would write protect the module pages should clearly be done,
but it can come in a later time. We have to make sure we interact
correctly with the page allocation debugging, as an example.
Here is the patch against x86.git 2.6.25-rc5 :
The shadow vmap for DEBUG_RODATA kernel text modification uses virt_to_page to
get the pages from the pointer address.
However, I think vmalloc_to_page would be required in case the page is used for
modules.
Since only the core kernel text is marked read-only, use kernel_text_address()
to make sure we only shadow map the core kernel text, not modules.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: akpm@linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
vSMP detection: access pci config space early in boot to detect if the
system is a vSMPowered box, and cache the result in a flag, so that
is_vsmp_box() retrieves the value of the flag always.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The sysenter path tries to enable interrupts immediately. Unfortunately
this doesn't work in a paravirt environment, because not enough kernel
state has been set up at that point (namely, pointing %fs to the kernel
percpu data segment). To fix this, defer ENABLE_INTERRUPTS until after
the kernel state has been set up.
Unfortunately this means that we're running with interrupts disabled
for a while without calling the IRQ tracing code, but that can't be
called without setting up %fs either.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch does clean up relocate_kernel_(32|64).S a bit by getting rid
of local PAGE_ALIGNED macro. We should use well-known PAGE_SIZE instead
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
make known_pat_cpu to think amd k8 and fam10h is ok too.
also make tom2 below to be WRBACK
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Sets up pat_init() infrastructure.
PAT MSR has following setting.
PAT
|PCD
||PWT
|||
000 WB _PAGE_CACHE_WB
001 WC _PAGE_CACHE_WC
010 UC- _PAGE_CACHE_UC_MINUS
011 UC _PAGE_CACHE_UC
We are effectively changing WT from boot time setting to WC.
UC_MINUS is used to provide backward compatibility to existing /dev/mem
users(X).
reserve_memtype and free_memtype are new interfaces for maintaining alias-free
mapping. It is currently implemented in a simple way with a linked list and
not optimized. reserve and free tracks the effective memory type, as a result
of PAT and MTRR setting rather than what is actually requested in PAT.
pat_init piggy backs on mtrr_init as the rules for setting both pat and mtrr
are same.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Initializing to zero is generally bad idea, I hope it is right for
__init data, too.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
do simple memtest after init_memory_mapping
use find_e820_area_size to find all ram range that is not reserved.
and do some simple bits test to find some bad ram.
if find some bad ram, use reserve_early to exclude that range.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
After an experimental cleanup of <linux/percpu.h>, these files were
exposed as invoking kmalloc() without including <linux/slab.h>.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I was trying to get the address of instruction to be executed
next after the kprobed instruction. But regs->eip in post_handler()
contains value which is useless to the user. It's pre-corrected value.
This value is difficult to use without access to resume_execution(), which
is not exported anyway.
I moved the invocation of post_handler() to *after* resume_execution().
Now regs->eip contains meaningful value in post_handler().
I do not think this change breaks any backward-compatibility.
To make meaning of the old value, post_handler() would need access to
resume_execution() which is not exported. I have difficulty to believe
that previous, uncorrected, regs->eip can be meaningfully used in
post_handler().
Signed-off-by: Yakov Lerner <iler.ml@gmail.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use force_sig in handle_vm86_trap like other machine traps do.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When we're stopped at syscall entry tracing, ptrace can change the %rax
value from -ENOSYS to something else. If no system call is actually made
because the syscall number (now in orig_rax) is bad, then we now always
reset %rax to -ENOSYS again.
This changes it to leave the return value alone after entry tracing.
That way, the %rax value set by ptrace is there to be seen in user mode
(or in syscall exit tracing). This is consistent with what the 32-bit
kernel does.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch removes the write-only timer_uses_ioapic_pin_0
(gsi can't be <= 15 in the line of it's fake usage in mpparse_32.c).
Spotted by the GNU C compiler.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Indicate TSCs are unreliable as time sources if the platform is
a multi chassi ScaleMP vSMPowered machine.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Re-arrange set_vsmp_pv_ops so that pv_ops are set only if
the platform has capability to support paravirtualized irq ops
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
- Fix the the build breakage when PARAVIRT is defined
but PCI is not
This fixes problem reported at:
http://marc.info/?l=linux-kernel&m=120525966600698&w=2
- Make is_vsmp_box() available even when PARAVIRT is not defined.
This is needed to determine if tsc's are reliable as a time source
even when PARAVIRT is not defined.
- split vsmp_init to use is_vsmp_box() and set_vsmp_pv_ops()
set_vsmp_pv_ops will do nothing if PCI is not enabled in the config.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
is_vsmp_box() currently does not work on vSMPowered systems, as pci cfg
space is not read correctly -- This patch fixes it.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
