do a proper idle-wakeup event on HLT as well - some CPUs stop the TSC
in HLT too, not just when going through the ACPI methods.
(the ACPI idle code already does this.)
[ update the 64-bit side too, as noticed by Jiri Slaby. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
scale the sched_clock() cyc_2_nsec scaling factor according to
CPU frequency changes.
[ mingo@elte.hu: simplified it and fixed it for SMP. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
cf http://lkml.org/lkml/2007/10/3/41
To summarize: on Linux, SA_ONSTACK decides whether you are already on the
signal stack based on the value of the SP at the time of a signal. If
you are not already inside the range, you are not "on the signal stack"
and so the new signal handler frame starts over at the base of the signal
stack.
sigaltstack (and sigstack before it) was invented in BSD. There, the
SA_ONSTACK behavior has always been different. It uses a kernel state
flag to decide, rather than the SP value. When you first take an
SA_ONSTACK signal and switch to the alternate signal stack, it sets the
SS_ONSTACK flag in the thread's sigaltstack state in the kernel.
Thereafter you are "on the signal stack" and don't switch SP before
pushing a handler frame no matter what the SP value is. Only when you
sigreturn from the original handler context do you clear the SS_ONSTACK
flag so that a new handler frame will start over at the base of the
alternate signal stack.
The undesireable effect of the Linux behavior is that an overflow of the
alternate signal stack can not only go undetected, but lead to a ring
buffer effect of clobbering the original handler frame at the base of the
signal stack for each successive signal that comes just after the
overflow. This is what Shi Weihua's test case demonstrates. Normally
this does not come up because of the signal mask, but the test case uses
SA_NODEFER for its SIGSEGV handler.
The other subtle part of the existing Linux semantics is that a simple
longjmp out of a signal handler serves to take you off the signal stack
in a safe and reliable fashion without having used sigreturn (nor having
just returned from the handler normally, which means the same). After
the longjmp (or even informal stack switching not via any proper libc or
kernel interface), the alternate signal stack stands ready to be used
again.
A paranoid program would allocate a PROT_NONE red zone around its
alternate signal stack. Then a small overflow would trigger a SIGSEGV in
handler setup, and be fatal (core dump) whether or not SIGSEGV is
blocked. As with thread stack red zones, that cannot catch all overflows
(or underflows). e.g., a local array as large as page size allocated in
a function called from a handler, but not actually touched before more
calls push more stack, could cause an overflow that silently pushes into
some unrelated allocated pages.
The BSD behavior does not do anything in particular about overflow. But
it does at least avoid the wraparound or "ring buffer effect", so you'll
just get a straightforward all-out overflow down your address space past
the low end of the alternate signal stack. I don't know what the BSD
behavior is for longjmp out of an SA_ONSTACK handler.
The POSIX wording relating to sigaltstack is pretty minimal. I don't
think it speaks to this issue one way or another. (The program that
overflows its stack is clearly in undefined behavior territory of one
sort or another anyhow.)
Given the longjmp issue and the potential for highly subtle complications
in existing programs relying on this in arcane ways deep in their code, I
am very dubious about changing the behavior to the BSD style persistent
flag. I think Shi Weihua's patches have a similar effect by tracking the
SP used in the last handler setup.
I think it would be sensible for the signal handler setup code to detect
when it would itself be causing a stack overflow. Maybe something like
the following patch (untested). This issue exists in the same way on all
machines, so ideally they would all do a similar check.
When it's the handler function itself or its callees that cause the
overflow, rather than the signal handler frame setup alone crossing the
boundary, this still won't help. But I don't see any way to distinguish
that from the valid longjmp case.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
add the DMI strings provided by Islam Amer <pharon@gmail.com>, for
the Compaq Presario V6000 (Quanta/30B7).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
make io_delay=0xed the default. This frees up port 0x80 which is
a debug port on some machines and locks up certain laptops.
Testing only for now. Try the io_delay=0x80 boot option if this does not
work for you.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
various changes to the in_p/out_p delay details:
- add the io_delay=none method
- make each method selectable from the kernel config
- simplify the delay code a bit by getting rid of an indirect function call
- add the /proc/sys/kernel/io_delay_type sysctl
- change 'io_delay=standard|alternate' to io_delay=0x80 and io_delay=0xed
- make the io delay config not depend on CONFIG_DEBUG_KERNEL
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: "David P. Reed" <dpreed@reed.com>
x86: provide a DMI based port 0x80 I/O delay override.
Certain (HP) laptops experience trouble from our port 0x80 I/O delay
writes. This patch provides for a DMI based switch to the "alternate
diagnostic port" 0xed (as used by some BIOSes as well) for these.
David P. Reed confirmed that port 0xed works for him and provides a
proper delay. The symptoms of _not_ working are a hanging machine,
with "hwclock" use being a direct trigger.
Earlier versions of this attempted to simply use udelay(2), with the
2 being a value tested to be a nicely conservative upper-bound with
help from many on the linux-kernel mailinglist but that approach has
two problems.
First, pre-loops_per_jiffy calibration (which is post PIT init while
some implementations of the PIT are actually one of the historically
problematic devices that need the delay) udelay() isn't particularly
well-defined. We could initialise loops_per_jiffy conservatively (and
based on CPU family so as to not unduly delay old machines) which
would sort of work, but...
Second, delaying isn't the only effect that a write to port 0x80 has.
It's also a PCI posting barrier which some devices may be explicitly
or implicitly relying on. Alan Cox did a survey and found evidence
that additionally some drivers may be racy on SMP without the bus
locking outb.
Switching to an inb() makes the timing too unpredictable and as such,
this DMI based switch should be the safest approach for now. Any more
invasive changes should get more rigid testing first. It's moreover
only very few machines with the problem and a DMI based hack seems
to fit that situation.
This also introduces a command-line parameter "io_delay" to override
the DMI based choice again:
io_delay=<standard|alternate>
where "standard" means using the standard port 0x80 and "alternate"
port 0xed.
This retains the udelay method as a config (CONFIG_UDELAY_IO_DELAY) and
command-line ("io_delay=udelay") choice for testing purposes as well.
This does not change the io_delay() in the boot code which is using
the same port 0x80 I/O delay but those do not appear to be a problem
as David P. Reed reported the problem was already gone after using the
udelay version. He moreover reported that booting with "acpi=off" also
fixed things and seeing as how ACPI isn't touched until after this DMI
based I/O port switch I believe it's safe to leave the ones in the boot
code be.
The DMI strings from David's HP Pavilion dv9000z are in there already
and we need to get/verify the DMI info from other machines with the
problem, notably the HP Pavilion dv6000z.
This patch is partly based on earlier patches from Pavel Machek and
David P. Reed.
Signed-off-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Document the fact that __save_processor_state() has to save all CPU
registers referred to by the kernel in case a different kernel is
used to load and restore a hibernation image containing it.
Sigend-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Michael Opdenacker reported:
For backward compatibility with earlier (< 2.6.24) kernels,
arch/i386/boot/bzImage or arch/x86_64/boot/bzImage symbolic links to
arch/x86/boot/bzImage are created when you build an x86 kernel. The
arch/i386 or arch/x86_64 directories are then created for this only
purpose.
Issue: these generated directories and symbolic links are *not cleaned
up* when you run "make mrproper" (and thus "make distclean"). This
disturbs the production of patches, because the source tree is left with
generated files and directories.
Sam has an alternative fix:
The directory is killed during make clean as opposed to make mrproper.
Reported-by: Michael Opdenacker <michael-lists@free-electrons.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Looks like IRQ 31 is assigned to timer 3, even without the patch!
I wonder who wrote the number 31. But the manual says that it is
zero by default.
I think we should check whether the timer has been allocated an IRQ before
proceeding to assign one to it. Here is a patch that does this.
Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Tested-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The userspace API for the HPET (see Documentation/hpet.txt) did not work. The
HPET_IE_ON ioctl was failing as there was no IRQ assigned to the timer
device. This patch fixes it by allocating IRQs to timer blocks in the HPET.
arch/x86/kernel/hpet.c | 13 +++++--------
drivers/char/hpet.c | 45 ++++++++++++++++++++++++++++++++++++++-------
include/linux/hpet.h | 2 +-
3 files changed, 44 insertions(+), 16 deletions(-)
Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The following scenario might leave PIT as a disfunctional clock source:
PIT is registered as clocksource
PM_TIMER is registered as clocksource and enables highres/dyntick mode
PIT is switched to oneshot mode
-> now the readout of PIT is bogus, but the user might select PIT
via the sysfs override, which would break the box as the time
readout is unusable.
Unregister the PIT clocksource when the PIT clock event device is switched
into shutdown / oneshot mode.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On x86 the PIT might become an unusable clocksource. Add an unregister
function to provide a possibilty to remove the PIT from the list of
available clock sources.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
PIT clocksource is registered unconditionally even when HPET is enabled
or when PIT is replaced by the local APIC timer. In both cases PIT can
not be used as it is stopped and the readout would be stale.
Prevent registering PIT in those cases.
patch depends on:
x86: offer is_hpet_enabled() on !CONFIG_HPET_TIMER too
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I was confused by FSEC = 10^15 NSEC statement, plus small whitespace
fixes. When there's copyright, there should be GPL.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
the logic in this function is just crazy. It's recursive, but we
can circumvent the creation for the kobject and whole creation of the
threshold_block if some conditions are met. That's why we see the
allocate_threshold_blocks so many times in the callstack, yet only a few
kobjects created.
Then we blow up in kobject_uevent_env() on the first debug printk.
Which means that we are just passing in garbage.
Man, this is one time that comments in code would have been very nice to
have, and why forward goto's into major code blocks are just evil...
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25: (1470 commits)
[IPV6] ADDRLABEL: Fix double free on label deletion.
[PPP]: Sparse warning fixes.
[IPV4] fib_trie: remove unneeded NULL check
[IPV4] fib_trie: More whitespace cleanup.
[NET_SCHED]: Use nla_policy for attribute validation in ematches
[NET_SCHED]: Use nla_policy for attribute validation in actions
[NET_SCHED]: Use nla_policy for attribute validation in classifiers
[NET_SCHED]: Use nla_policy for attribute validation in packet schedulers
[NET_SCHED]: sch_api: introduce constant for rate table size
[NET_SCHED]: Use typeful attribute parsing helpers
[NET_SCHED]: Use typeful attribute construction helpers
[NET_SCHED]: Use NLA_PUT_STRING for string dumping
[NET_SCHED]: Use nla_nest_start/nla_nest_end
[NET_SCHED]: Propagate nla_parse return value
[NET_SCHED]: act_api: use PTR_ERR in tcf_action_init/tcf_action_get
[NET_SCHED]: act_api: use nlmsg_parse
[NET_SCHED]: act_api: fix netlink API conversion bug
[NET_SCHED]: sch_netem: use nla_parse_nested_compat
[NET_SCHED]: sch_atm: fix format string warning
[NETNS]: Add namespace for ICMP replying code.
...
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (68 commits)
[MIPS] remove Documentation/mips/GT64120.README
[MIPS] Malta: remaining bits of the board support code cleanup
[MIPS] Malta: make the helper function static
[MIPS] Malta: fix braces at single statement blocks
[MIPS] Malta, Atlas: move an extern function declaration to the header file
[MIPS] Malta: Use C89 style for comments
[MIPS] Malta: else should follow close brace in malta_int.c
[MIPS] Malta: remove a superfluous comment
[MIPS] Malta: include <linux/cpu.h> instead of <asm/cpu.h>
[MIPS] Malta, Atlas, Sead: remove an extern from .c files
[MIPS] Malta: fix oversized lines in malta_int.c
[MIPS] Malta: remove a dead function declaration
[MIPS] Malta: use tabs not spaces
[MIPS] Malta: set up the screen info in a separate function
[MIPS] Malta: check the PCI clock frequency in a separate function
[MIPS] Malta: use the KERN_ facility level in printk()
[MIPS] Malta: use Linux kernel style for structure initialization
[MIPS]: constify function pointer tables
[MIPS] compat: handle argument endianess of sys32_(f)truncate64 with merge_64
[MIPS] Cobalt 64-bits kernels can be safely unmarked experimental
...
This patch factors out the code, which handles the Bonito system
controller. The case of not supporting the DMA coherency is handled
separately to make the logic obvious. Besides, a couple of empty
lines added to beautify the code even further.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
One helper function can become static. This patch adds the needed
keyword.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch fixes a couple of warnings reported by checkpatch.pl.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This was compile-tested using default configs for the boards
affected by this change.
This patch does not introduce any functional changes.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Remove comments in C99 style and make checkpatch.pl happy.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch fixes two errors reported by checkpatch.pl.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Using the "We die here" comment right before calling the die()
function is an extremely vivid example of overcommenting.
Remove the redundant comment and save one line.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The checkpatch.pl script reported a few warnings about header files.
This patch fixes these warnings.
Compile-tested using the default Malta config.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch moves the "extern" declaration for the function
mips_reboot_setup() from the board setup .c files to the
header file include/asm-mips/mips-boards/generic.h.
This fixes a warning produced by the checkpatch.pl script.
No functional changes introduced.
This was compile-tested by building the kernel for all
three boards affected by this change. All builds finished
successfully.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch fixes all "line over 80 characters" warnings found
in arch/mips/mips-boards/malta/malta_int.c by the checkpatch.pl
script.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Neither is the mips_rtc_get_time() routine defined anywhere in
the MIPS architecture-specific code, nor does anyone call it any
more. This patch removes the extern declaration of this fossil.
This patch does not introduce any functional changes.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch fixes all "use tabs not spaces" warnings reported by
the checkpatch.pl script on the board-specific files.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds a separate short and sweet function to initialize
the screen_info global variable.
This improves readability of the Malta board setup code.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds a separate short and sweet function to check the
PCI clock frequency. This is to improve readability of the Malta
setup code.
Along the way, a couple of coding style violations are fixed.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds the KERN_ macros to printk() calls. Where applicable,
spaces are replaced by tabs.
These changes noticeably reduce the number of errors and warnings
reported by the checkpatch.pl script for the malta_int.c file.
Before the patch: total: 47 errors, 20 warnings, 354 lines checked
After the patch: total: 34 errors, 7 warnings, 355 lines checked
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch reformats the structure initialization code thus
making the latter look idiomatic.
No functional changes introduced.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The Qemu platform was originally implemented to have an easily supportable
platform until Qemu reaches a state where it emulates a real world system.
Since the latest release Qemu is capable of emulating the MIPSsim and
Malta platforms, so this goal has been reached. The Qemu plaform is also
rather underfeatured so less useful than a Malta emulation.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
