Commit Graph

90976 Commits

Author SHA1 Message Date
Glauber Costa
d09d815c1b x86: isolate coherent mapping functions
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>
2008-04-19 19:19:58 +02:00
Glauber Costa
8e8edc6401 x86: move dma_coherent functions to pci-dma.c
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
fae9a0d8ca x86: merge iommu initialization parameters
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
8e0c379718 x86: merge dma_supported
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
bca5c09663 x86: move pci fixup to pci-dma.c
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
116890d556 x86: move x86_64-specific to common code.
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
cb5867a5d8 x86: move initialization functions to pci-dma.c
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
f9c258de34 x86: unify pci-nommu
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
85c246ee16 x86: move definition to pci-dma.c
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
d741bde26d x86: use dma_length in i386
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
5b3e5b7273 x86: use WARN_ON in mapping functions
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
30db2cbf38 x86: use sg_phys in x86_64
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
e4dcdd6b4f x86: Add flush_write_buffers in nommu functions
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
9f9ab46d55 x86: implement mapping_error in pci-nommu_64.c
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
d5df63f48a x86: delete empty functions from pci-nommu_64.c
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
459121c9ec x86: introduce pci-dma.c
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>
2008-04-19 19:19:57 +02:00
Mark McLoughlin
19e395afb4 x86: move dma_supported and dma_set_mask to pci-dma_32.c, fix
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
b7107a3d9d x86: delete the arch-specific dma-mapping headers.
all the code that is left is ready to be merged as-is
in 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>
2008-04-19 19:19:57 +02:00
Glauber Costa
ae17a63b09 x86: move ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY to dma-mapping.h
define it conditionally to 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>
2008-04-19 19:19:57 +02:00
Glauber Costa
c786df08f6 x86: unify dma_mapping_error
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>
2008-04-19 19:19:57 +02:00
Glauber Costa
7c18341665 x86: provide a bad_dma_address symbol for i386
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>
2008-04-19 19:19:56 +02:00
Glauber Costa
b48ee71352 x86: align to clflush size
Do it instead of using the conservative approach we're currently
doing. This is the way x86_64 does, and this patch makes this piece
of code the same between them, ready to be integrated.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:56 +02:00
Glauber Costa
802c1f6648 x86: move dma_supported and dma_set_mask to pci-dma_32.c
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>
2008-04-19 19:19:56 +02:00
Glauber Costa
3cb6a91711 x86: move dma_cache_sync to common header
they are the same in both architectures.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:56 +02:00
Ingo Molnar
2be621498d x86: dma-ops on highmem fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:56 +02:00
Glauber Costa
4d92fbf231 x86: move dma_map_page and dma_unmap_page to common header
They are similar enough to do this move.
the macro version is ugly, and we use inline functions 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
8d396ded71 x86: move alloc and free coherent to common header
they are the same between architectures. (except for the fact
that x86_64 has duplicate code)

move them 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
e7f3a913f9 x86: move dma_sync_sg_for_device to common header
i386 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
ed435dee9c x86: move dma_sync_sg_for_cpu to common header
i386 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
713623326c x86: move dma_sync_single_range_for_device to common header
i386 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
627610fcb7 x86: move dma_sync_single_range_for_cpu to common header
i386 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
9231b269e0 x86: move dma_sync_single_for_device to common header
i386 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
c01dd8cf7d x86: move dma_sync_single_for_cpu to common header
i386 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
72c784f82c x86: move dma_unmap_sg to common header
i386 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>
2008-04-19 19:19:56 +02:00
Glauber Costa
16a3ce9bae x86: move dma_map_sg to common header
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>
2008-04-19 19:19:56 +02:00
Glauber Costa
0cb0ae6832 x86: move dma_unmap_single to common header
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>
2008-04-19 19:19:56 +02:00
Glauber Costa
22456b9714 x86: implement dma_map_single through dma_ops
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>
2008-04-19 19:19:56 +02:00
Glauber Costa
6f5366354b x86: move dma_ops struct definition to dma-mapping.h
take it off the x86_64 specific 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>
2008-04-19 19:19:56 +02:00
Yinghai Lu
752bea4abb x86: reserve dma32 early for gart
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>
2008-04-19 19:19:55 +02:00
Suresh Siddha
6ec6e0d9f2 srat, x86: add support for nodes spanning other nodes
For example, If the physical address layout on a two node system with 8 GB
memory is something like:
node 0: 0-2GB, 4-6GB
node 1: 2-4GB, 6-8GB

Current kernels fail to boot/detect this NUMA topology.

ACPI SRAT tables can expose such a topology which needs to be supported.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00
Roland McGrath
8705a49c35 x86 vDSO: compile with -g, 64-bit
The 64-bit vDSO's sources are compiled with -g0 for no good reason.
Using -g when enabled lets their separate debug files be used at
runtime via build ID matching, same as we can see 32-bit vDSO's
assembly sources.

Signed-off-by: Roland McGrath <roland@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00
Suresh Siddha
2adee9b30d x86: fpu xstate split fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00
Suresh Siddha
1679f2710a x86: fpu xstate split cleanup
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00
Suresh Siddha
aa283f4927 x86, fpu: lazy allocation of FPU area - v5
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>
2008-04-19 19:19:55 +02:00
Suresh Siddha
61c4628b53 x86, fpu: split FPU state from task struct - v5
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>
2008-04-19 19:19:55 +02:00
Ingo Molnar
fa5c463941 x86: rename find_max_pfn() to propagate_e820_map()
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>
2008-04-19 19:19:55 +02:00
Thomas Gleixner
d8bb6f4c16 x86: tsc prevent time going backwards
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>
2008-04-19 19:19:55 +02:00
Erik Bosman
f132697326 generic, x86: add tests for prctl PR_GET_TSC and PR_SET_TSC
This patch adds three tests that test whether the PR_GET_TSC and
PR_SET_TSC commands have the desirable effect.

The tests check whether the control register is updated correctly
at context switches and try to discover bugs while enabling/disabling
the timestamp counter.

Signed-off-by: Erik Bosman <ejbosman@cs.vu.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00
Erik Bosman
529e25f646 x86: implement prctl PR_GET_TSC and PR_SET_TSC
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>
2008-04-19 19:19:55 +02:00
Erik Bosman
8fb402bccf generic, x86: add prctl commands PR_GET_TSC and PR_SET_TSC
This patch adds prctl commands that make it possible
to deny the execution of timestamp counters in userspace.
If this is not implemented on a specific architecture,
prctl will return -EINVAL.

ned-off-by: Erik Bosman <ejbosman@cs.vu.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00