The prevent_tail_call() macro works around the problem of the compiler
clobbering argument words on the stack, which for asmlinkage functions
is the caller's (user's) struct pt_regs. The tail/sibling-call
optimization is not the only way that the compiler can decide to use
stack argument words as scratch space, which we have to prevent.
Other optimizations can do it too.
Until we have new compiler support to make "asmlinkage" binding on the
compiler's own use of the stack argument frame, we have work around all
the manifestations of this issue that crop up.
More cases seem to be prevented by also keeping the incoming argument
variables live at the end of the function. This makes their original
stack slots attractive places to leave those variables, so the compiler
tends not clobber them for something else. It's still no guarantee, but
it handles some observed cases that prevent_tail_call() did not.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch also resolves hangs on boot:
http://lkml.org/lkml/2008/2/23/263http://bugzilla.kernel.org/show_bug.cgi?id=10093
The bug was causing once-in-few-reboots 10-15 sec wait during boot on
certain laptops.
Earlier commit 40d6a14662 added
smp_call_function in cpu_idle_wait() to kick cpus that are in tickless
idle. Looking at cpu_idle_wait code at that time, code seemed to be
over-engineered for a case which is rarely used (while changing idle
handler).
Below is a simplified version of cpu_idle_wait, which just makes a dummy
smp_call_function to all cpus, to make them come out of old idle handler
and start using the new idle handler. It eliminates code in the idle
loop to handle cpu_idle_wait.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make NOMMU-mode work with base addresses other than 0xC0000000 by:
(1) Giving the code that sets up the protection registers the right address
in __sdram_base. Rather than being hard coded to 0xC0000000, the value
of __page_offset is obtained from the linker script.
(2) Eliminate the check in __switch_to() that verifies the current thread
info is in the 0xCxxxxxxx region.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use traps 120-126 to emulate atomic cmpxchg32, xchg32, and XOR-, OR-, AND-, SUB-
and ADD-to-memory operations for userspace.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gcc expects all toplevel assembly to return to the original section type.
The code in alteranative.c does not do this. This caused some strange bugs
in sched-devel where code would end up in the .rodata section and when
the kernel sets the NX bit on all .rodata, the kernel would crash when
executing this code.
This patch adds a .previous marker to return the code back to the
original section.
Credit goes to Andrew Pinski for telling me it wasn't a gcc bug but a
bug in the toplevel asm code in the kernel. ;-)
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
flush_cache_vmap / flush_cache_vunmap were calling flush_cache_all which -
having been deprecated - turned into a nop ...
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In time_cpufreq_notifier() the cpu id to act upon is held in freq->cpu. Use it
instead of smp_processor_id() in the call to set_cyc2ns_scale().
This makes the preempt_*able() unnecessary and lets set_cyc2ns_scale() update
the intended cpu's cyc2ns.
Related mail/thread: http://lkml.org/lkml/2007/12/7/130
Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
revert:
| commit 47001d6033
| Author: Thomas Gleixner <tglx@linutronix.de>
| Date: Tue Apr 1 19:45:18 2008 +0200
|
| x86: tsc prevent time going backwards
it has been identified to cause suspend regression - and the
commit fixes a longstanding bug that existed before 2.6.25 was
opened - so it can wait some more until the effects are better
understood.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
[SPARC64]: Fix user accesses in regset code.
[SPARC64]: Fix FPU saving in 64-bit signal handling.
We handle a broken tsc these days, so no need to panic. We clear the
TSC bit when tsc_init decides it's unreliable (eg. under lguest w/ bad
host TSC), leading to bogus panic.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Building UP kernel with KGDB enabled produces the following errors and warning
(fatal due to -Werror in arch/mips/kernel/Makefile):
In file included from arch/mips/kernel/gdb-stub.c:142:
include/asm/smp.h:25:1: "raw_smp_processor_id" redefined
In file included from include/linux/sched.h:69,
from arch/mips/kernel/gdb-stub.c:126:
include/linux/smp.h:88:1: this is the location of the previous definition
In file included from arch/mips/kernel/gdb-stub.c:142:
include/asm/smp.h:62: error: redefinition of 'smp_send_reschedule'
include/linux/smp.h:102: error: previous definition of 'smp_send_reschedule' was here
include/asm/smp.h: In function `smp_send_reschedule':
include/asm/smp.h:65: error: dereferencing pointer to incomplete type
arch/mips/kernel/gdb-stub.c: At top level:
arch/mips/kernel/gdb-stub.c:660: warning: 'kgdb_wait' defined but not used
Fix the errors by not directly including <asm/smp.h> (which is already included
by <linux/smp.h>) and the warning by enclosing kgdb_wait() in #ifdef CONFIG_SMP.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Long overdue update of the m68k defconfigs
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The default defconfig should be one from arch/m68k/configs/
arch/m68k/defconfig was not exactly identical to amiga_defconfig but
also considering how long they have been without any update that doesn't
seem to have been on purpose.
Signed-off-by: Adrian Bunk <adrian.bunk@movial.fi>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commits:
commit 37a47db8d7
Author: Balaji Rao <balajirrao@gmail.com>
Date: Wed Jan 30 13:30:03 2008 +0100
x86: assign IRQs to HPET timers, fix
and
commit e3f37a54f6
Author: Balaji Rao <balajirrao@gmail.com>
Date: Wed Jan 30 13:30:03 2008 +0100
x86: assign IRQs to HPET timers
have been identified to cause a regression on some platforms due to
the assignement of legacy IRQs which makes the legacy devices
connected to those IRQs disfunctional.
Revert them.
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=10382
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We already catch most of the TSC problems by sanity checks, but there
is a subtle bug which has been in the code for ever. 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>
Fix obsolete printks in aperture-64. We used not to handle missing
agpgart, but we handle it okay now.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
right now if there's no CPU support for nmi_watchdog=2 we'll just
refuse it silently.
print a useful warning.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
implement nmi_watchdog=2 on this class of CPUs:
cpu family : 15
model : 6
model name : Intel(R) Pentium(R) D CPU 3.00GHz
the watchdog's ->setup() method is safe anyway, so if the CPU
cannot support it we'll bail out safely.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This avoids using wrmsr on MSR_IA32_DEBUGCTLMSR when it's not needed.
No wrmsr ever needs to be done if noone has ever used block stepping.
Without this change, using ptrace on 2.6.25 on an x86 KVM guest
will tickle KVM's missing support for the MSR and crash the guest
kernel. Though host KVM is the buggy one, this makes for a regression
in the guest behavior from 2.6.24->2.6.25 that we can easily avoid.
I also corrected some bad whitespace.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[POWERPC] Fix MPC5200 (not B!) device tree so FEC ethernet works
[POWERPC] mpc5200: Amalgamated DTS fixes and updates
[POWERPC] Fix rtas_flash procfs interface
[POWERPC] Fix deadlock with mmu_hash_lock in hash_page_sync
[POWERPC] Fix iSeries hard irq enabling regression
[POWERPC] Fix CPM2 SCC1 clock initialization.
[POWERPC] Fix defconfigs so we dont set both GENRTC and RTCLIB
[POWERPC] fsldma: Use compatiable binding as spec
[POWERPC] sata_fsl: reduce compatibility to fsl,pq-sata
[POWERPC] 83xx: enable usb in 837x rdb and 83xx defconfigs
[POWERPC] 83xx: Fix wrong USB phy type in mpc837xrdb dts
The calculation of the FPU reg save area pointer
was wrong.
Based upon an OOPS report from Tom Callaway.
Signed-off-by: David S. Miller <davem@davemloft.net>
This gets the FEC ethernet driver working again on the lite5200
platform.
The FEC driver is also compatible with the MPC5200, not only with the
MPC5200B, so this adds a suitable entry to the driver's match list.
Furthermore this adds the settings for the PHY in the dts file for the
Lite5200. Note, that this is not exactly the same as in the
Lite5200B, because the PHY is located at f0003000:01 for the 5200, and
at :00 for the 5200B. This was tested on a Lite5200 and a Lite5200B,
both booted a kernel via tftp and mounted the root via nfs
successfully.
Signed-off-by: René Bürgel <r.buergel@unicontrol.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Handling of the proc_dir_entry->count was changed in 2.6.24-rc5.
After this change, the default value for pde->count is 1 and not 0 as
before. Therefore, if we want to check whether our procfs file is
already opened (already in use), we have to check if pde->count is
greater than 2 rather than 1.
Signed-off-by: Maxim Shchetynin <maxim@de.ibm.com>
Signed-off-by: Jens Osterkamp <jens@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
hash_page_sync() takes and releases the low level mmu hash
lock in order to sync with other processors disposing of page
tables. Because that lock can be needed to service hash misses
triggered by interrupt handlers, taking it must be done with
interrupts off. However, hash_page_sync() appears to be called
with interrupts enabled, thus causing occasional deadlocks.
We fix it by making sure hash_page_sync() masks interrupts while
holding the lock.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
A subtle bug sneaked into iSeries recently. On this platform, we must
not normally clear MSR:EE (the hardware external interrupt enable)
except for short periods of time. Taking an interrupt while
soft-disabled doesn't cause us to clear it for example.
The iSeries kernel expects to mostly run with MSR:EE enabled at all
times except in a few exception entry/exit code paths. Thus
local_irq_enable() doesn't check if it needs to hard-enable as it
expects this to be unnecessary on iSeries.
However, hard_irq_disable() _does_ cause MSR:EE to be cleared,
including on iSeries. A call to it was recently added to the
context switch code, thus causing interrupts to become disabled
for a long periods of time, causing the iSeries watchdog to kick
in under some circumstances and other nasty things.
This patch fixes it by making local_irq_enable() properly re-enable
MSR:EE on iSeries. It basically removes a return statement here
to make iSeries use the same code path as everybody else. That does
mean that we might occasionally get spurious decrementer interrupts
but I don't think that matters.
Another option would have been to make hard_irq_disable() a nop
on iSeries but I didn't like it much, in case we have good reasons
to hard-disable.
Part of the patch is fixes to make sure the hard_enabled PACA field
is properly set on iSeries as it used not to be before, since it
was mostly unused.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
A missing break statement in a switch caused cpm2_clk_setup() to initialize
SCC2 instead of SCC1.
Signed-off-by: Laurent Pinchart <laurentp@cse-semaphore.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Fix the problem that makedumpfile sometimes fails on x86_64 machine.
This patch adds the symbol "phys_base" to a vmcoreinfo data. The
vmcoreinfo data has the minimum debugging information only for dump
filtering. makedumpfile (dump filtering command) gets it to distinguish
unnecessary pages, and makedumpfile creates a small dumpfile.
On x86_64 kernel which compiled with CONFIG_PHYSICAL_START=0x0 and
CONFIG_RELOCATABLE=y, makedumpfile fails like the following:
# makedumpfile -d31 /proc/vmcore dumpfile
The kernel version is not supported.
The created dumpfile may be incomplete.
_exclude_free_page: Can't get next online node.
makedumpfile Failed.
#
The cause is the lack of the symbol "phys_base" in a vmcoreinfo data.
If the symbol "phys_base" does not exist, makedumpfile considers an
x86_64 kernel as non relocatable. As the result, makedumpfile
misunderstands the physical address where the kernel is loaded, and it
cannot translate a kernel virtual address to physical address correctly.
To fix this problem, this patch adds the symbol "phys_base" to a
vmcoreinfo data.
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make dma_alloc_coherent respect gfp flags (__GFP_COMP is one that
matters).
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Tested-by: Michael Cree <mcree@orcon.net.nz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/ralf/upstream-linus:
[MIPS] XSS1500: Fix compilation
[MIPS] Bigsur: make defconfig more useful.
[MIPS] Alchemy: work around clock misdetection on early Au1000
[MIPS] Add missing 4KEC TLB refill handler
[MIPS] BCM1480: Fix PCI/HT IO access
[MIPS] Fix the installation condition of MIPS clocksource
[MIPS] Check for GCC r10k-cache-barrier support
[MIPS] I8253: Export i2853_lock to modules.
[MIPS] VPE loader: Check result of memory allocation.
This patch fixes the compilation of the Au1000 XSS1500
board setup and irqmap code.
Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Work around the CPU clock miscalculation on Au1000DA/HA/HB due the
sys_cpupll register being write-only, i.e. actually do what the comment
before cal_r4off() function advertised for years but the code failed at.
This is achieved by just giving user a chance to define the clock
explicitly in the board config. via CONFIG_SOC_AU1000_FREQUENCY option,
defaulting to 396 MHz if the option is not given...
The patch is based on the AMD's big unpublished patch, the issue seems to
be an undocumented errata (or feature :-)...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Early 4KEc were MIPS32r1 and therefore need some love to get a TLB
refill handler.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
- removed check for enable HT-PCI bridges, because some CFE version
init only the needed one and scanning works even with disabled HT
links
- implemented I/O access behind HT PCI busses
- fixed pci_map for IO resource behind PCI bridge
Tested with E100 and Tulip driver.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Check whether gcc supports -mr10-cache-barrier=1 and issue a cleaner
error message if not. This option is needed to build working SGI IP28
kernels.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
And while at it, make it a little cleaner. Issue originally reported by
Tiejun Chen (tiejun.chen@windriver.com).
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
as prescribed in Documentation/powerpc/booting-without-of.txt.
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
