Commit Graph

37414 Commits

Author SHA1 Message Date
Paul Mundt
c153a58e71 Merge branch 'sh/dwarf-unwinder' of git://github.com/mfleming/linux-2.6 into sh/dwarf-unwinder 2009-08-22 03:49:58 +09:00
Paul Mundt
4ab8f241f6 sh: Export unwind_stack() to satisfy modular oprofile.
If the oprofile code is built as a module, unwind_stack() as used by the
oprofile backtrace code is not available, causing build breakage.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-22 03:43:15 +09:00
Matt Fleming
5580e9044d sh: Handle the DWARF op, DW_CFA_undefined
Allow a DWARF register to have an undefined value. When applied to the
DWARF return address register this lets lets us label a function as
having no direct caller, e.g. kernel_thread_helper().

Signed-off-by: Matt Fleming <matt@console-pimps.org>
2009-08-21 13:04:11 +01:00
Matt Fleming
5480675dc6 sh: Fix bug calculating the end of the FDE instructions
The 'end' member of struct dwarf_fde denotes one byte past the end of
the CFA instruction stream for an FDE. The value of 'end' was being
calcualted incorrectly, it was being set too high. This resulted in
dwarf_cfa_execute_insns() interpreting data past the end of valid
instructions, thus causing all sorts of weird crashes.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
2009-08-21 13:04:10 +01:00
Matt Fleming
fe98dd31eb sh: Setup the frame pointer in handle_interrupt
When CONFIG_DWARF_UNWINDER is enabled setup r14 in handle_interrupt, so
that we can figure out what function was running when we were
interrupted.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
2009-08-21 13:04:10 +01:00
Matt Fleming
b344e24a8e sh: unwinder: Introduce UNWINDER_BUG() and UNWINDER_BUG_ON()
We can't assume that if we execute the unwinder code and the unwinder
was already running that it has faulted. Clearly two kernel threads can
invoke the unwinder at the same time and may be running simultaneously.

The previous approach used BUG() and BUG_ON() in the unwinder code to
detect whether the unwinder was incapable of unwinding the stack, and
that the next available unwinder should be used instead. A better
approach is to explicitly invoke a trap handler to switch unwinders when
the current unwinder cannot continue.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
2009-08-21 13:02:44 +01:00
Matt Fleming
97efbbd588 sh: unwinder: Set the flags for DW_CFA_val_offset ops as DWARF_VAL_OFFSET
The handling of DW_CFA_val_offset ops was incorrectly using the
DWARF_REG_OFFSET flag but the register's value cannot be calculated
using the DWARF_REG_OFFSET method. Create a new flag to indicate that a
different method must be used to calculate the register's value even
though there is no implementation for DWARF_VAL_OFFSET yet; it's mainly
just a place holder.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
2009-08-21 13:02:44 +01:00
Matt Fleming
fb3f3e7fc6 sh: unwinder: Fix memory leak and create our own kmem cache
Plug a memory leak in dwarf_unwinder_dump() where we didn't free the
memory that we had previously allocated for the DWARF frames and DWARF
registers.

Now is also a opportune time to implement our own mempool and kmem
cache. It's a good idea to have a certain number of frame and register
objects in reserve at all times, so that we are guaranteed to have our
allocation satisfied even when memory is scarce. Since we have pools to
allocate from we can implement the registers for each frame as a linked
list as opposed to a sparsely populated array. Whilst it's true that the
lookup time for a linked list is larger than for arrays, there's only
usually a maximum of 8 registers per frame. So the overhead isn't that
much of a concern.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
2009-08-21 13:02:43 +01:00
Paul Mundt
97f361e249 sh: unwinder: Move initialization to early_initcall() and tidy up locking.
This moves the initialization over to an early_initcall(). This fixes up
some lockdep interaction issues. At the same time, kill off some
superfluous locking in the init path.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-17 05:07:38 +09:00
Matt Fleming
cd7246f0e2 sh: Add support for DWARF GNU extensions
Also, remove the "fix" to DW_CFA_def_cfa_register where we reset the
frame's cfa_offset to 0. This action is incorrect when handling
DW_CFA_def_cfa_register as the DWARF spec specifically states that the
previous contents of cfa_offset should be used with the new
register. The reason that I thought cfa_offset should be reset to 0 was
because it was being assigned a bogus value prior to executing the
DW_CFA_def_cfa_register op. It turns out that the bogus cfa_offset value
came from interpreting .cfi_escape pseudo-ops (those used by the GNU
extensions) as CFA_DW_def_cfa ops.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
2009-08-16 12:48:53 +01:00
Matt Fleming
b955873bf5 sh: Try again at getting the initial return address for an unwind
The previous hack for calculating the return address for the first frame
we unwind (dwarf_unwinder_dump) didn't always work. The problem was that
it assumed once it read the rule for calculating the return address,
there would be no new rules for calculating it. This isn't true because
the way in which the CFA is calculated can change as you progress
through a function and the return address is figured out using the
CFA. Therefore, the way to calculate the return address can change.

So, instead of using some offset from the beginning of
dwarf_unwind_stack which is just a flakey approach, and instead of
executing instructions from the FDE until the return address is setup,
we now figure out the pc in dwarf_unwind_stack() just before we call
dwarf_cfa_execute_insns().

Signed-off-by: Matt Fleming <matt@console-pimps.org>
2009-08-16 12:48:53 +01:00
Paul Mundt
38f9ddf441 sh: Merge the _32/_64 variants of arch/sh/kernel/Makefile.
This uses the BITS export as per x86 in order to allow the same Makefile
to be used.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-16 03:35:26 +09:00
Paul Mundt
60e0a4c7ad Merge branch 'sh/stable-updates' 2009-08-15 12:59:42 +09:00
Magnus Damm
237674e050 sh: sh7724 ddr self-refresh changes
This patch updates the SuperH Mobile sleep assembly code with
support for DBSC memory controller found in the sh7724 processor.

Without this fix the memory hooked up to the sh7724 processor
will never enter self-refresh mode before suspending to ram. The
effect of this is that the memory contents most likeley will be
lost upon resume which may or may not be what you want.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-15 12:58:50 +09:00
Magnus Damm
9747e78b30 sh: use in-soc KEYSC on se7724
This patch updates the Solution Engine 7724 board code to use
in-SoC KEYSC resources for the keyboard platform device. Using
the in-SoC key scan controller fixes a crash-during-resume issue.

Without this patch the KEYSC hardware block located in the board
specific FPGA is used together with an external IRQ which is
routed through the FPGA and handled by some board specific demux
code. This board specific FPGA interrupt code does not implement
desc->set_wake() so the enable_irq_wake() call in the sh_keysc
driver will fail at suspend-to-ram time and the disable_irq_wake()
will bomb out when resuming.

Changing the platform data to use the in-SoC KEYSC hardware makes
the se7724 board support code less special which is a good thing.
Also, the board specific KEYSC pin setup code selects in-SoC pin
functions already which makes the current FPGA platform device data
look like a typo.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-15 12:58:47 +09:00
Matt Fleming
180aa6e6aa sh: Set the cfa_offset to 0 if we see a DW_CFA_def_cfa_register op
The way that the CFA is calculated can change as we progress through a
function. If we see a DW_CFA_def_cfa_register op we need to reset the
frame's cfa_offset value which may have been previously setup.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-15 08:07:43 +09:00
Paul Mundt
7dd6662a92 sh: delay slot future proofing via EXPMASK on SH-4A parts.
This implements EXPMASK initialization code for SH-4A parts, where it is
possible to disable compat features that will go away in newer cores.
Presently this includes disabling support for non-nop instructions in the
rte delay slot, as well as a sleep instruction being placed in a delay
slot (neither of which the kernel does any longer). As a result of this,
any future offenders will have illegal slot exceptions generated for
them.

Associative writes for the memory-mapped cache array are still left
enabled, until such a point that special cache operations for SH-4A are
provided to move off of the current (and rather dated) SH-4 versions.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-15 07:43:21 +09:00
Paul Mundt
7a90e00dda sh: Make sure rte delay slots are nopped out on all parts.
Future SH parts do not support any instruction but a nop in the rte delay
slot, so make the change for all offending parts. SH-5 is excluded from
this, and already has its own set of restrictions with regards to rte
delay slot handling.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-15 07:41:45 +09:00
Paul Mundt
606b4c992f sh: stacktrace: Properly terminate the trace entry buffer.
This inserts a ULONG_MAX entry at the end of the valid entries in the
stack trace buffer so the default code doesn't need to scan to the end of
available slots. This also makes the trace buffer termination behaviour
consistent with the other architectures.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-15 01:11:37 +09:00
Paul Mundt
f9967e23c1 sh: flag the default unwinder as reliable.
This flags the default unwinder as reliable, as it tends to be reliable
enough for the purposes of the stacktrace buffer. We leave the unreliable
cases for the unwind methods that we know to be completely broken.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-15 01:09:03 +09:00
Paul Mundt
48e4d4604b sh: stacktrace: Add reliability checks in address saving ops.
This adopts the reliability checks from the x86 stacktrace code so known
bad addresses are not recorded in the stack trace buffer.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-15 01:05:46 +09:00
Paul Mundt
0fc11e3618 sh: unwinder: Convert frame allocations to GFP_ATOMIC.
save_stack_trace_tsk() and friends can be called from atomic context (as
triggered by latencytop), and subsequently hit two problematic allocation
points that were using GFP_KERNEL (these were dwarf_unwind_stack() and
dwarf_frame_alloc_regs()). Convert these over to GFP_ATOMIC and get
latencytop working with the DWARF unwinder.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-14 23:58:37 +09:00
Paul Mundt
718dbf376a Merge branch 'sh/dwarf-unwinder' 2009-08-14 05:10:57 +09:00
Matt Fleming
f826466772 sh: Delete DWARF_ARCH_UNWIND_OFFSET
Trying to figure out the best value for DWARF_ARCH_UNWIND_OFFSET is
tricky at best. Various things can change the size (and offset from the
beginning of the function) of the prologue. Notably, turning on ftrace
adds calls to mcount at the beginning of functions, thereby pushing the
prologue further into the function.

So replace DWARF_ARCH_UNWIND_OFFSET with some code that continues to
execute CFA instructions until the value of return address register is
defined. This is safe to do because we know that the return address must
have been pushed onto the frame before our first function call; we just
can't figure out where at compile-time.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-14 05:00:21 +09:00
Paul Mundt
f54aab4a74 sh: oprofile: Kill off dead valid_kernel_stack().
This is no longer used, kill it off.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-14 04:59:50 +09:00
Linus Torvalds
3493e84de6 Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf_counter: Report the cloning task as parent on perf_counter_fork()
  perf_counter: Fix an ipi-deadlock
  perf: Rework/fix the whole read vs group stuff
  perf_counter: Fix swcounter context invariance
  perf report: Don't show unresolved DSOs and symbols when -S/-d is used
  perf tools: Add a general option to enable raw sample records
  perf tools: Add a per tracepoint counter attribute to get raw sample
  perf_counter: Provide hw_perf_counter_setup_online() APIs
  perf list: Fix large list output by using the pager
  perf_counter, x86: Fix/improve apic fallback
  perf record: Add missing -C option support for specifying profile cpu
  perf tools: Fix dso__new handle() to handle deleted DSOs
  perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not available
  perf report: Show the tid too in -D
  perf record: Fix .tid and .pid fill-in when synthesizing events
  perf_counter, x86: Fix generic cache events on P6-mobile CPUs
  perf_counter, x86: Fix lapic printk message
2009-08-13 12:24:33 -07:00
Linus Torvalds
1c2ffff407 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix oops in identify_cpu() on CPUs without CPUID
  x86: Clear incorrectly forced X86_FEATURE_LAHF_LM flag
  x86, mce: therm_throt - change when we print messages
  x86: Add reboot quirk for every 5 series MacBook/Pro
2009-08-13 12:08:44 -07:00
Paul Mundt
bf43a160ff sh: unwinder: Restore put_unaligned() for an unaligned destination.
The destination address might be unaligned, so set it with
put_unaligned() for safety. This restores the previous behaviour, albeit
through the proper API.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-14 03:06:13 +09:00
Paul Mundt
3497447f15 sh: unwinder: Fix up usage of unaligned accessors.
This was using internal symbols for unaligned accesses, bypassing the
exposed interface for variable sized safe accesses. This converts all of
the __get_unaligned_cpuXX() users over to get_unaligned() directly,
relying on the cast to select the proper internal routine.

Additionally, the __put_unaligned_cpuXX() case is superfluous given that
the destination address is aligned in all of the current cases, so just
drop that outright.

Furthermore, this switches to the asm/unaligned.h header instead of the
asm-generic version, which was silently bypassing the SH-4A optimized
unaligned ops.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-14 02:10:59 +09:00
Matt Fleming
cafb0ddac6 sh: Add CFI annotations for exception return.
Annotate various assembly code paths with CFI assembler directives so
that DWARF unwind info is available for the unwinder.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-14 02:02:07 +09:00
Matt Fleming
0b930489b8 sh: Setup the frame register in asm code
In order to use DWARF unwinder info the frame register has to contain a
valid value. Whilst GCC takes care of this for C code, we have to do it
ourselves for assembly.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-14 01:59:55 +09:00
Matt Fleming
bd353861c7 sh: dwarf unwinder support.
This is a first cut at a generic DWARF unwinder for the kernel. It's
still lacking DWARF64 support and the DWARF expression support hasn't
been tested very well but it is generating proper stacktraces on SH for
WARN_ON() and NULL dereferences.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-14 01:58:43 +09:00
Matt Fleming
0eff9f66de sh: Use the new stack unwinder API
Instead of implementing our own stack unwinder via dump_trace() we
should use the new stack unwinder API because it is more modular. This
change allows us to decouple the interface for generating stacktraces
from the implementation of a stack unwinder.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-13 19:52:53 +09:00
Matt Fleming
bf61ad1f87 sh: Allow multiple stack unwinders to be setup
Provide an interface for registering stack unwinders, where each
unwinder is given a rating that describes its accuracy and
complexity. The more accurate an unwinder is, the more complex it is.

If a the current stack unwinder faults, then the stack unwinder with the
next highest accuracy will be used in its place (provided one is
available). For example, this allows unwinders, such as the DWARF
unwinder, to liberally sprinkle BUG()s to catch badly formed DWARF debug
info.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-13 19:49:03 +09:00
Matt Fleming
4e14dfc722 sh: Use the generalized stacktrace ops
Copy the stacktrace ops code from x86 and provide a central function for
use by functions that need to dump a callstack.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-13 11:50:08 +09:00
Marcin Slusarz
922b0dc59b sh: use printk_once
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-13 11:48:08 +09:00
Paul Mundt
e290861f99 Merge branch 'sh/stable-updates' 2009-08-13 11:48:01 +09:00
Magnus Damm
dbefd606a3 sh: fix i2c init order on ap325rxa V2
Convert the AP325RXA board code to register devices at
arch_initcall() time instead of device_initcall(). This
fix unbreaks pcf8563 RTC driver support.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-13 11:43:43 +09:00
Magnus Damm
ba3a170191 sh: fix i2c init order on Migo-R V2
Convert the Migo-R board code to register devices at
arch_initcall() time instead of __initcall(). This fix
unbreaks migor_ts touch screen driver support.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-13 11:39:02 +09:00
Magnus Damm
ba9a633787 sh: convert processor device setup functions to arch_initcall()
Convert the processor platform device setup
functions from __initcall() and sometimes
device_initcall() to arch_initcall().

This makes sure that the platform devices are
registered a bit earlier so the devices are
available when drivers register using initcall
levels earlier than device_initcall().

A good example is platform devices needed by
i2c-sh_mobile.c which registers a bit earlier
using subsys_initcall().

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-13 11:36:33 +09:00
Ingo Molnar
04da8a43da perf_counter, x86: Fix/improve apic fallback
Johannes Stezenbach reported that his Pentium-M based
laptop does not have the local APIC enabled by default,
and hence perfcounters do not get initialized.

Add a fallback for this case: allow non-sampled counters
and return with an error on sampled counters. This allows
'perf stat' to work out of box - and allows 'perf top'
and 'perf record' to fall back on a hrtimer based sampling
method.

( Passing 'lapic' on the boot line will allow hardware
  sampling to occur - but if the APIC is disabled
  permanently by the hardware then this fallback still
  allows more systems to use perfcounters. )

Also decouple perfcounter support from X86_LOCAL_APIC.

-v2: fix typo breaking counters on all other systems ...

Reported-by: Johannes Stezenbach <js@sig21.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-12 14:12:49 +02:00
Ondrej Zary
e8055139d9 x86: Fix oops in identify_cpu() on CPUs without CPUID
Kernel is broken for x86 CPUs without CPUID since 2.6.28. It
crashes with NULL pointer dereference in identify_cpu():

766        generic_identify(c);
767
768-->     if (this_cpu->c_identify)
769               this_cpu->c_identify(c);

this_cpu is NULL. This is because it's only initialized in
get_cpu_vendor() function, which is not called if the CPU has
no CPUID instruction.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
LKML-Reference: <200908112000.15993.linux@rainbow-software.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-12 11:49:41 +02:00
Roel Kluin
e7369e01eb arch/ia64/kernel/iosapic: missing test after ioremap()
Missing test after ioremap()

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
2009-08-11 14:52:11 -07:00
Fenghua Yu
5359dffd43 ia64/topology.c: exit cache_add_dev when kobject_init_and_add fails
Make cache_add_dev exit sysfs when kobject_init_and_add returns an error.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
2009-08-11 14:52:11 -07:00
Fenghua Yu
bf2a4c7270 arch/ia64/Makefile: Remove -mtune=merced in IA64 kernel build
Between GCC version 3.4.0 and 4.3.3 (including 3.4.0 and 4.3.3), -mtune=merced
is implemented in GCC. Starting from 4.4.0, -mtune=merced is deprecated.

Even implemented in versions between 3.4.0 and 4.3.3, the -mtune=merced
feature has been broken in some of the versions. For example, GCC 4.1.2 reports
interanl tuning function errors during kernel building with -mtune=merced. Or
GCC Bugzilla 16130 reports another -mtune=merced issue on GCC 3.4.1.

So I would remove the -mtune=merced from IA64 kernel build. Without this option,
kernel on Merced will remain the same except losing an unstable and out-of-date
performance tunning feature.

Since GCC version 3.4.0, -mtune=mckinley has been implemented. The
-mtune=mckinley option functions the same as mtune=itanium2. And mtune=itanium2
is the default option. So we don't need to add mtune=mckinley either since its
been the default option in any GCC version which implements this option.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
2009-08-11 14:52:11 -07:00
Jaswinder Singh Rajput
b5a8879347 IA64: includecheck fix: ia64, pgtable.h
fix the following 'make includecheck' warning:

  arch/ia64/include/asm/pgtable.h: asm/processor.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
2009-08-11 14:52:11 -07:00
Jaswinder Singh Rajput
cfa5f809e3 IA64: includecheck fix: ia64, ia64_ksyms.c
fix the following 'make includecheck' warning:

  arch/ia64/kernel/ia64_ksyms.c: asm/page.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
2009-08-11 14:52:10 -07:00
Johannes Weiner
8d6f9af919 ia64: boolean __test_and_clear_bit
__test_and_clear_bit() returns a bitfield with the tested-for bit set.
Make it consistent with the other bitops - of ia64 but also every
other architecture - and return a boolean value.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
2009-08-11 14:52:10 -07:00
Fenghua Yu
51b89f7a66 Bug Fix arch/ia64/kernel/pci-dma.c: fix recursive dma_supported() call in iommu_dma_supported()
In commit 160c1d8e40,
dma_ops->dma_supported = iommu_dma_supported;

This dma_ops->dma_supported is first called in platform_dma_init() during kernel
boot. Then dma_ops->dma_supported will be called recursively in
iommu_dma_supported.

Kernel can not boot because kernel can not get out of iommu_dma_supported until
it runs out of stack memory.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
2009-08-11 14:52:10 -07:00
Kevin Winchester
fbd8b1819e x86: Clear incorrectly forced X86_FEATURE_LAHF_LM flag
Due to an erratum with certain AMD Athlon 64 processors, the
BIOS may need to force enable the LAHF_LM capability.
Unfortunately, in at least one case, the BIOS does this even
for processors that do not support the functionality.

Add a specific check that will clear the feature bit for
processors known not to support the LAHF/SAHF instructions.

Signed-off-by: Kevin Winchester <kjwinchester@gmail.com>
Acked-by: Borislav Petkov <petkovbb@googlemail.com>
LKML-Reference: <4A80A5AD.2000209@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-11 13:34:54 +02:00