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It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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This converts ia64 to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single().
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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As noted by Akinobu Mita alloc_bootmem and related functions never return
NULL and always return a zeroed region of memory. Thus a NULL test or
memset after calls to these functions is unnecessary.
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Call check_sal_cache_flush() after platform_setup() as
check_sal_cache_flush() now relies on being able to call platform
vector code.
Problem was introduced by: 3463a93def55c309f3c0d0a8aaf216be3be42d64
"Update check_sal_cache_flush to use platform_send_ipi()"
Signed-off-by: Jes Sorensen <jes@sgi.com>
Tested-by: Alex Chiang: <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] Fix CONFIG_IA64_SGI_UV build error
[IA64] Update check_sal_cache_flush to use platform_send_ipi()
[IA64] perfmon: fix async exit bug
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check_sal_cache_flush is used to detect broken firmware that drops
pending interrupts.
The old implementation schedules a timer interrupt for itself in
the future by getting the current value of the Interval Timer
Counter + 1000 cycles, waits for the interrupt to be pended, calls
SAL_CACHE_FLUSH, and finally checks to see if the interrupt is
still pending.
This implementation can cause problems for virtual machine code if
the process of scheduling the timer interrupt takes more than 1000
cycles; the virtual machine can end up sleeping for several hundred
years while waiting for the ITC to wrap around.
The fix is to use platform_send_ipi. The processor will still send
an interrupt to itself, using the IA64_IPI_DM_INT delivery mode,
which causes the IPI to look like an external interrupt. The rest
of the SAL_CACHE_FLUSH + checking to see if the interrupt is still
pending remains unchanged.
This fix has been boot tested successfully on:
- intel tiger2
- hp rx6600
- hp rx5670
The rx5670 has known buggy firmware, where SAL_CACHE_FLUSH drops
pending interrupts. A boot test on this machine showed this message
on the console:
SAL: SAL_CACHE_FLUSH drops interrupts; PAL_CACHE_FLUSH will be used instead
Which proves that the self-inflicted IPI approach is viable. And
as expected, the other tested platforms correctly did not display
the warning.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This is a SLIT sanity checking patch. It moves slit_valid() function to
generic ACPI code and does sanity checking for both x86 and ia64. It sets up
node_distance with LOCAL_DISTANCE and REMOTE_DISTANCE when hitting invalid
SLIT table on ia64. It also cleans up unused variable localities in
acpi_parse_slit() on x86.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
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Move the cleanup of the async queue to the close callback from the flush
callback. This avoids losing asynchronous overflow notifications when
the file descriptor is shared by multiple processes and one terminates.
Signed-off-by: Stephane Eranian <eranian@gmail.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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move interrupt, page_fault, non_syscall, dispatch_unaligned_handler and
dispatch_to_fault_handler to avoid lack of instructin space.
The change set 4dcc29e1574d88f4465ba865ed82800032f76418 bloated
SAVE_MIN_WITH_COVER, SAVE_MIN_WITH_COVER_R19 so that it bloated the
functions which uses those macros.
In the native case, only dispatch_illegal_op_fault had to be moved.
When paravirtualized case the all functions which use the macros need
to be moved to avoid the lack of space.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Introduce pv_time_ops which adds hook to steal time accounting.
On virtualized environment, cpus are shared by many guests and
steal time is the time which is used for other guests.
On virtualized environtment, streal time should be accounted.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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introduce pv_irq_ops which adds hooks to paravirtualize irq related
operations.
On virtualized environment, interruption may be replaced by something
virtualization friendly. So the irq related operation also may need
paravirtualization.
This patch adds necessary hooks to paravirtualize irq related operations.
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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add hooks to paravirtualize iosapic which is a real hardware resource.
On virtualized environment it may be replaced something virtualized
friendly.
Define pv_iosapic_ops and add the hooks.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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environment.
define pv_init_ops hooks which represents various initialization
hooks for paravirtualized environment. and add hooks.
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Make NR_IRQ overridable by each pv instances.
Pv instance may need each own number of irqs so that
NR_IRQS should be the maximum number of nr_irqs each
pv instances need.
Cc: Jes Sorensen <jes@sgi.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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paravirtualize ia64_swtich_to, ia64_leave_syscall and ia64_leave_kernel.
They include sensitive or performance critical privileged instructions
so that they need paravirtualization.
To paravirtualize them by single source and multi compile
they are converted into indirect jump. And define each pv instances.
Cc: Keith Owens <kaos@ocs.com.au>
Cc: "Dong, Eddie" <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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paravirtualize ivt.S which implements fault handler in hand written
assembly code.
They includes sensitive or performance critical privileged instructions.
So they need paravirtualization.
Cc: Keith Owens <kaos@ocs.com.au>
Cc: tgingold@free.fr
Cc: Akio Takebe <takebe_akio@jp.fujitsu.com>
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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paravirtualize minstate.h which are hand written assembly code.
They include sensitive or performance critical privileged
instructions. So that they are appropriate for paravirtualization.
Cc: Keith Owens <kaos@ocs.com.au>
Cc: Akio Takebe <takebe_akio@jp.fujitsu.com>
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Preparation for paravirtualization of hand written assembly code.
They are paravirtualized by single source code and compiled multi times.
To tell those files for target (including native), add one defines.
Cc: "Dong, Eddie" <eddie.dong@intel.com>
Cc: Keith Owens <kaos@ocs.com.au>
Cc: tgingold@free.fr
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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introduce pv_cpu_ops to paravirtualize privleged instructions
which are defined by ia64 intrinsics.
make them indirect C function calls by introducing function
tables, pv_cpu_ops.
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This patch adds a setup hook in the very early boot sequence
before start_kernel() to initialize paravirtualization stuff.
The hook will be set by each pv loader code or by using multi entry point.
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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introduce pv_info which describes some randome info about
underlying execution environment.
Cc: Jes Sorensen <jes@sgi.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Move the LOAD_OFFSET definition from vmlinux.lds.S into system.h.
On paravirtualized environments, it is necessary to detect the
execution environment. One of the solutions is the multi entry point.
The multi entry point allows a boot loader to start the kernel execution
from the entry point which is different from the ELF entry point.
The non standard entry point will defined as the specialized elf note
which contains the LMA of the entry point symbol.
The constant, LOAD_OFFSET, is necessary to calculate the symbol's LMA.
Move the definition into the public header file to make it available
to the multi entry point support.
Cc: "He, Qing" <qing.he@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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remove extern declaration of handle_IPI() in irq_ia64.c.
Instead, declare it in asm-ia64/smp.h.
Later handle_IPI() will be referenced from another file.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Problem: An application violating the architectural rules regarding
operation dependencies and having specific Register Stack Engine (RSE)
state at the time of the violation, may result in an illegal operation
fault and invalid RSE state. Such faults may initiate a cascade of
repeated illegal operation faults within OS interruption handlers.
The specific behavior is OS dependent.
Implication: An application causing an illegal operation fault with
specific RSE state may result in a series of illegal operation faults
and an eventual OS stack overflow condition.
Workaround: OS interruption handlers that switch to kernel backing
store implement a check for invalid RSE state to avoid the series
of illegal operation faults.
The core of the workaround is the RSE_WORKAROUND code sequence
inserted into each invocation of the SAVE_MIN_WITH_COVER and
SAVE_MIN_WITH_COVER_R19 macros. This sequence includes hard-coded
constants that depend on the number of stacked physical registers
being 96. The rest of this patch consists of code to disable this
workaround should this not be the case (with the presumption that
if a future Itanium processor increases the number of registers, it
would also remove the need for this patch).
Move the start of the RBS up to a mod32 boundary to avoid some
corner cases.
The dispatch_illegal_op_fault code outgrew the spot it was
squatting in when built with this patch and CONFIG_VIRT_CPU_ACCOUNTING=y
Move it out to the end of the ivt.
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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acpi_unregister_gsi() should "undo" what acpi_register_gsi() does.
On systems that have legacy interrupts, acpi_unregister_gsi erroneously calls
iosapci_unregister_intr() which is wrong to do and causes a loud warning.
acpi_unregister_gsi() should just return in these cases.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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There is only palinfo_handle_smp as (indirect) user of palinfo_smp_call (by
way of smp_call_function_single) and surely palinfo_handle_smp never pass
NULL as parameter for info.
Signed-off-by: Simon Holm Thøgersen <odie@cs.aau.dk>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Fix a typo, and coding style cleanups for pfm_handle_work().
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This patch does:
- make comment at next to resched check more robust
- move "re-check" comments to next to where change predicate regs
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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[Bug-fix for "[BUG?][2.6.25-mm1] sleeping during IRQ disabled"]
This patch does:
- enable interrupts before calling schedule() as same as others, ex. x86
- enable interrupts during ia64_do_signal() and ia64_sync_krbs()
- do_notify_resume_user() is still called with interrupts disabled, since
we can take short path of fsys_mode if-statement quickly.
- pfm_handle_work() is also called with interrupts disabled, since
it can deal interrupt mask within itself.
- fix/add some comments/notes
Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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The sequence executed in check_sal_cache_flush:
- pend a timer interrupt
- call SAL_CACHE_FLUSH
- see if interrupt is still pending
can hang HP machines with buggy SAL_CACHE_FLUSH implementations.
Provide a kernel command-line argument to allow users skip this
check if desired. Using this parameter will force ia64_sal_cache_flush
to call ia64_pal_cache_flush() instead of SAL_CACHE_FLUSH.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Some IA64 machines map all cell-local memory above 4 GB (32 bit limit).
However, in most cases, the kernel needs some memory below that limit that is
DMA-capable. So in this machine configuration, the crashkernel will be reserved
above 4 GB.
For machines that use SWIOTLB implementation because they lack an I/O MMU
the low memory is required by the SWIOTLB implementation. In that case,
it doesn't make sense to reserve the crashkernel at all because it's unusable
for kdump.
A special case is the "hpzx1" machine vector. In theory, it has a I/O MMU, so
it can be booted above 4 GB. However, in the kdump case that is not possible
because of changeset 51b58e3e26ebfb8cd56825c4b396ed251f51dec9:
On HP zx1 machines, the 'machvec=dig' parameter is needed for the kdump
kernel to avoid problems with the HP sba iommu. The problem is that during
the boot of the kdump kernel, the iommu is re-initialized, so in-flight DMA
from improperly shutdown drivers causes an IOTLB miss which leads to an
MCA. With kdump, the idea is to get into the kdump kernel with as little
code as we can, so shutting down drivers properly is not an option.
The workaround is to add 'machvec=dig' to the kdump kernel boot parameters.
This makes the kdump kernel avoid using the sba iommu altogether, leaving
the IOTLB intact. Any ongoing DMA falls harmlessly outside the kdump
kernel. After the kdump kernel reboots, all devices will have been
shutdown properly and DMA stopped.
This patch pushes that functionality into the sba iommu initialization
code, so that users won't have to find the obscure documentation telling
them about 'machvec=dig'.
This means that also for hpzx1 it's not possible to boot when all
memory is above the 4 GB limit. So the only machine vectors that can handle
this case are "sn2" and "uv".
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This patch adds the basic IA64 machvec infrastructure to support
the SGI "UV" platform.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Races galore... General rule: as soon as it's in descriptor table,
it's over; another thread might have started IO on it/dup2() it
elsewhere/dup2() something *over* it/etc. fd_install() is the very
last step one should take - it's a point of no return.
Besides, the damn thing leaked on failure exits...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Replace TIF_RESTORE_SIGMASK with TS_RESTORE_SIGMASK and define
our own set_restore_sigmask() function. This saves the costly
SMP-safe set_bit operation, which we do not need for the sigmask
flag since TIF_SIGPENDING always has to be set too.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Fix indenting of switch statement to follow CodingStyle, and
pull out handling of call_data into an inlined function.
I confirmed that applying this fix doesn't affect assembled code.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This patch silences:
WARNING: vmlinux.o(.text+0x44672): Section mismatch in
reference from the function arch_register_cpu() to the
function .cpuinit.text:register_cpu()
Changes are based on codes in arch/x86/kernel/topology.c
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This patch removes following warning:
WARNING: vmlinux.o(.exit.text+0xb1): Section mismatch in
reference from the function palinfo_exit() to the variable
.cpuinit.data:palinfo_cpu_notifier
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This patch shuts up the following:
WARNING: vmlinux.o(.text+0x7102): Section mismatch in
reference from the function fixup_irqs() to the function
.devinit.text:ia64_disable_timer()
Removing ia64_disable_timer() is safe because there are no functions
calling it other than the fixup_irqs(),
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This patch kills:
WARNING: vmlinux.o(.text+0x1702): Section mismatch in
reference from the function acpi_register_ioapic() to the
function .devinit.text:iosapic_init()
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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TIF_RESTORE_SIGMASK no longer needs to be in the _TIF_WORK_* masks.
Those low bits are scarce. Renumber TIF_RESTORE_SIGMASK to free one up.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Legacy HP ia64 platforms currently cannot provide
/proc/cpuinfo/physical_id due to legacy SAL/PAL implementations.
However, that physical topology information can be obtained
via ACPI.
Provide an interface that gives ACPI one last chance to provide
physical_id for these legacy platforms. This logic only comes
into play iff:
- ACPI actually provides slot information for the CPU
- we lack a valid socket_id
Otherwise, we don't do anything.
Since x86 uses the ACPI processor driver as well, we provide a nop
stub function for arch_fix_phys_package_id() in asm-x86/topology.h
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Commit 113134fcbca83619be4c68d0ca66db6093777b5d changed the flow of
control when calling PAL_LOGICAL_TO_PHYSICAL and SAL_PHYSICAL_ID_INFO.
With the change, if a platform did not implement the latter, a useless
printk would appear in the boot log:
ia64_sal_pltid failed with -1
So let's check the return code and only printk on a true error, and do
not print anything in the unimplemented case. While we're in there,
clean up some stylistic issues too.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Enable the uncached allocator to allocate multiple pages of contiguous
uncached memory.
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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- remove unused 'irq' argument from pfm_do_interrupt_handler()
- remove pointless cast to void*
- add KERN_xxx prefix to printk()
- remove braces around singleton C statement
- in tioce_provider.c, start tioce_dma_consistent() and
tioce_error_intr_handler() function declarations in column 0
This change's main purpose is to prepare for the patchset in
jgarzik/misc-2.6.git#irq-remove, that explores removal of the
never-used 'irq' argument in each interrupt handler.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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There are many notify_die() and almost all take same style with
ia64_mca_spin(). This patch defines macros and replace them all,
to reduce lines and to improve readability.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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There are 3 hooks in MCA handler, but this DIE_MCA_MONARCH_PROCESS
event does not notified other than for the first monarch.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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While testing with CONFIG_VIRT_CPU_ACCOUNTING=y, I found that
I occasionally get very huge system time in some threads.
So I dug the issue and finally noticed that it was caused
because of an interrupt which interrupt in the following window:
> [arch/ia64/kernel/entry.S: (!CONFIG_PREEMPT && CONFIG_VIRT_CPU_ACCOUNTING)]
>
> ENTRY(ia64_leave_syscall)
> :
> (pUStk) rsm psr.i
> cmp.eq pLvSys,p0=r0,r0 // pLvSys=1: leave from syscall
> (pUStk) cmp.eq.unc p6,p0=r0,r0 // p6 <- pUStk
> .work_processed_syscall:
> adds r2=PT(LOADRS)+16,r12
> (pUStk) mov.m r22=ar.itc // fetch time at leave
> adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
> ;;
> <<< window: from here >>>
> (p6) ld4 r31=[r18] // load current_thread_info()->flags
> ld8 r19=[r2],PT(B6)-PT(LOADRS)
> adds r3=PT(AR_BSPSTORE)+16,r12
> ;;
> mov r16=ar.bsp
> ld8 r18=[r2],PT(R9)-PT(B6)
> (p6) and r15=TIF_WORK_MASK,r31 // any work other than TIF_SYSCALL_TRACE?
> ;;
> ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE)
> (p6) cmp4.ne.unc p6,p0=r15, r0 // any special work pending?
> (p6) br.cond.spnt .work_pending_syscall
> ;;
> ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
> ld8 r11=[r3],PT(CR_IIP)-PT(R11)
> (pNonSys) break 0 // bug check: we shouldn't be here if pNonSys is TRUE!
> ;;
> invala
> <<< window: to here >>>
> rsm psr.i | psr.ic // turn off interrupts and interruption collection
If pUStk is true, it means we are going to return user mode, hence we fetch
ar.itc to get time at leave from system.
It seems that it is not possible to interrupt the window if pUStk is true,
because interrupts are disabled early. And also disabling interrupt makes
sense because it is safe for referring current_thread_info()->flags.
However interrupting the window while pUStk is true was possible.
The route was:
ia64_trace_syscall
-> .work_pending_syscall_end
-> .work_processed_syscall
Only in case entering the window from this route, interrupts are enabled
during in the window even if pUStk is true. I suppose interrupts must be
disabled here anyway if pUStk is true.
I'm not sure but afraid that what kind of bad effect were there, other
than crazy system time which I found.
FYI, there was a commit 6f6d75825dc49b082906b84537b4df28293c2977 that
points out a bug at same point(exit of ia64_trace_syscall) in 2006.
It can be said that there was an another bug.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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