* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc:
Remove DEBUG_SEMAPHORE from Kconfig
Improve semaphore documentation
Simplify semaphore implementation
Add down_timeout and change ACPI to use it
Introduce down_killable()
Generic semaphore implementation
Add semaphore.h to kernel_lock.c
Fix quota.h includes
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Newer s390 models have a breaking-event-address-recording register.
Each time an instruction causes a break in the sequential instruction
execution, the address is saved in that hardware register. On a program
interrupt the address is copied to the lowcore address 272-279, which
makes it software accessible.
This patch changes the program check handler and the stack overflow
checker to copy the value into the pt_regs argument.
The oops output is enhanced to show the last known breaking address.
It might give additional information if the stack trace is corrupted.
The feature is only available on 64 bit.
The new oops output looks like:
[---------snip----------]
Modules linked in: vmcp sunrpc qeth_l2 dm_mod qeth ccwgroup
CPU: 2 Not tainted 2.6.24zlive-host #8
Process modprobe (pid: 4788, task: 00000000bf3d8718, ksp: 00000000b2b0b8e0)
Krnl PSW : 0704200180000000 000003e000020028 (vmcp_init+0x28/0xe4 [vmcp])
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3
Krnl GPRS: 0000000004000002 000003e000020000 0000000000000000 0000000000000001
000000000015734c ffffffffffffffff 000003e0000b3b00 0000000000000000
000003e00007ca30 00000000b5bb5d40 00000000b5bb5800 000003e0000b3b00
000003e0000a2000 00000000003ecf50 00000000b2b0bd50 00000000b2b0bcb0
Krnl Code: 000003e000020018: c0c000040ff4 larl %r12,3e0000a2000
000003e00002001e: e3e0f0000024 stg %r14,0(%r15)
000003e000020024: a7f40001 brc 15,3e000020026
>000003e000020028: e310c0100004 lg %r1,16(%r12)
000003e00002002e: c020000413dc larl %r2,3e0000a27e6
000003e000020034: c0a00004aee6 larl %r10,3e0000b5e00
000003e00002003a: a7490001 lghi %r4,1
000003e00002003e: a75900f0 lghi %r5,240
Call Trace:
([<000000000014b300>] blocking_notifier_call_chain+0x2c/0x40)
[<000000000015735c>] sys_init_module+0x19d8/0x1b08
[<0000000000110afc>] sysc_noemu+0x10/0x16
[<000002000011cda2>] 0x2000011cda2
Last Breaking-Event-Address:
[<000003e000020024>] vmcp_init+0x24/0xe4 [vmcp]
[---------snip----------]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Most noteable part of this commit is the new local header file entry.h
which contains all the function declarations of functions that get only
called from asm code or are arch internal. That way we can avoid extern
declarations in C files.
This is more or less the same that was done for sparc64.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This way we get rid of s390's NO_IDLE_HZ and use the generic dynticks
variant instead. In addition we get high resolution timers for free.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Remove the program check generating monitor calls and use function
calls instead. Theres is no real advantage in using monitor calls,
but they do make debugging harder, because of all the program checks
it generates.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
The new function supports setting of permissions for the debugfs files
created by the debug feature. In addition to that, the function provides
uid and gid as parameters for future use. Currently only root is allowed
for uid and gid.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Add get_clock_xt to read an 8 byte clock value using store clock
extended (STCKE) and use get_clock_xt for sched_clock. STCKE should
be faster than STCK on newer machines.
Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
If vertical cpu polarization is active then the hypervisor will
dispatch certain cpus for a longer time than other cpus for maximum
performance. For example if a guest would have three virtual cpus,
each of them with a share of 33 percent, then in case of vertical
cpu polarization all of the processing time would be combined to a
single cpu which would run all the time, while the other two cpus
would get nearly no cpu time.
There are three different types of vertical cpus: high, medium and
low. Low cpus hardly get any real cpu time, while high cpus get a
full real cpu. Medium cpus get something in between.
In order to switch between the two possible modes (default is
horizontal) a 0 for horizontal polarization or a 1 for vertical
polarization must be written to the dispatching sysfs attribute:
/sys/devices/system/cpu/dispatching
The polarization of each single cpu can be figured out by the
polarization sysfs attribute of each cpu:
/sys/devices/system/cpu/cpuX/polarization
horizontal, vertical:high, vertical:medium, vertical:low or unknown.
When switching polarization the polarization attribute may contain
the value unknown until the configuration change is done and the
kernel has figured out the new polarization of each cpu.
Note that running a system with different types of vertical cpus may
result in significant performance regressions. If possible only one
type of vertical cpus should be used. All other cpus should be
offlined.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Add s390 backend so we can give the scheduler some hints about the
cpu topology.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Make stfle visible so other code can call this.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This is just a port of 83bd01024b
"x86: protect against sigaltstack wraparound".
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
/sys/firmware/reipl/nss/name contains the nss name when defsys or
savesys command has been executed. If the defsys or savesys command
fails the kernel_nss_name has to be cleared since a reipl on that
nss name won't be possible.
Signed-off-by: Hongjie Yang <hongjie@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Normally this should not happen, but it's cleaner to do it that way.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Compile smp.o with -Wno-nonnull so gcc stops warning about memcpy
being used with a null parameter. Also remove the workaround code
and use a char * cast instead of a void * cast to do computations.
Cc: Bastian Blank <bastian@waldi.eu.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If a machine check handling is pending when the idle loop is entered
default_idle will be left with timer ticks and virtual timer disabled.
Fix this by "calling" the idle_chain. Also a BUG_ON(!in_interrupt) in
start_hz_timer must be removed since the function now gets called from
non interrupt context as well.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Since a5fbb6d106
"KVM: fix !SMP build error" smp_call_function isn't a define anymore
that folds into nothing but a define that calls up_smp_call_function
with all parameters. Hence we cannot #ifdef out the unused code
anymore...
This seems to be the preferred method, so do this for s390 as well.
arch/s390/kernel/time.c: In function 'etr_sync_clock':
arch/s390/kernel/time.c:825: error: 'clock_sync_cpu_start' undeclared
arch/s390/kernel/time.c:862: error: 'clock_sync_cpu_end' undeclared
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Just copy the first 512 read-only bytes of the current cpu lowcore if
a new cpu gets onlined. The rest is zeroed out and must be explicitly
initialized. Current code just copies the entire lowcore and
initializes the needed fields.
This should reveal bugs in future enhancements quite early.
Also when the lowcore of the first cpu is replaced this is now done
atomically (no interrupts, no machine checks).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If both NO_IDLE_HZ and VIRT_TIMER are disabled default_idle won't load
an enabled wait psw and busy loop instead. This is because the
idle_chain is empty and the return value of atomic_notifier_call_chain
will be NOTIFY_DONE, which causes default_idle to return instead of
loading an enabled wait psw.
Fix this by calling __atomic_notifier_call_chain instead and add proper
return value handling.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for different number of page table levels dependent
on the highest address used for a process. This will cause a 31 bit
process to use a two level page table instead of the four level page
table that is the default after the pud has been introduced. Likewise
a normal 64 bit process will use three levels instead of four. Only
if a process runs out of the 4 tera bytes which can be addressed with
a three level page table the fourth level is dynamically added. Then
the process can use up to 8 peta byte.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently we possibly lookup the pid in the wrong pid namespace. So
seq_file convert proc_pid_status which ensures the proper pid namespaces is
passed in.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: another build fix]
[akpm@linux-foundation.org: s390 build fix]
[akpm@linux-foundation.org: fix task_name() output]
[akpm@linux-foundation.org: fix nommu build]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andrew Morgan <morgan@kernel.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.
This patch:
Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past. This is to avoid conflicts.
Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
[S390] dcss: Initialize workqueue before using it.
[S390] Remove BUILD_BUG_ON() in vmem code.
[S390] sclp_tty/sclp_vt220: Fix scheduling while atomic
[S390] dasd: fix panic caused by alias device offline
[S390] dasd: add ifcc handling
[S390] latencytop s390 support.
[S390] Implement ext2_find_next_bit.
[S390] Cleanup & optimize bitops.
[S390] Define GENERIC_LOCKBREAK.
[S390] console: allow vt220 console to be the only console
[S390] Fix couple of section mismatches.
[S390] Fix smp_call_function_mask semantics.
[S390] Fix linker script.
[S390] DEBUG_PAGEALLOC support for s390.
[S390] cio: Add shutdown callback for ccwgroup.
[S390] cio: Update documentation.
[S390] cio: Clean up chsc response code handling.
[S390] cio: make sense id procedure work with partial hardware response
This is the new timerfd API as it is implemented by the following patch:
int timerfd_create(int clockid, int flags);
int timerfd_settime(int ufd, int flags,
const struct itimerspec *utmr,
struct itimerspec *otmr);
int timerfd_gettime(int ufd, struct itimerspec *otmr);
The timerfd_create() API creates an un-programmed timerfd fd. The "clockid"
parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME.
The timerfd_settime() API give new settings by the timerfd fd, by optionally
retrieving the previous expiration time (in case the "otmr" parameter is not
NULL).
The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit
is set in the "flags" parameter. Otherwise it's a relative time.
The timerfd_gettime() API returns the next expiration time of the timer, or
{0, 0} if the timerfd has not been set yet.
Like the previous timerfd API implementation, read(2) and poll(2) are
supported (with the same interface). Here's a simple test program I used to
exercise the new timerfd APIs:
http://www.xmailserver.org/timerfd-test2.c
[akpm@linux-foundation.org: coding-style cleanups]
[akpm@linux-foundation.org: fix ia64 build]
[akpm@linux-foundation.org: fix m68k build]
[akpm@linux-foundation.org: fix mips build]
[akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds]
[heiko.carstens@de.ibm.com: fix s390]
[akpm@linux-foundation.org: fix powerpc build]
[akpm@linux-foundation.org: fix sparc64 more]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove BUILD_BUG_ON() in vmem code since it causes build failures if
the size of struct page increases. Instead calculate at compile time
the address of the highest physical address that can be added to the
1:1 mapping.
This supposed to fix a build failure with the page owner tracking leak
detector patches as reported by akpm.
page-owner-tracking-leak-detector-broken-on-s390.patch can be removed
from -mm again when this is merged.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix console detection logic to support configurations in which the
vt220 console is the only available Linux console.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix couple of section mismatches. And since we touch the code
anyway change the IPL code to use C99 initializers.
Cc: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make sure func isn't called on the local cpu just like on all other
architectures that implement this function.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fixes this warning:
vmlinux: warning: allocated section `.text' not in segment
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch consolidate all definitions of .init.text, .init.data
and .exit.text, .exit.data section definitions in
the generic vmlinux.lds.h.
This is a preparational patch - alone it does not buy
us much good.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Git commit 86ef5c9a8e forgot a few
lock_cpu_hotplug/unlock_cpu_hotplug pairs in arch/s390/kernel/smp.c
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds the s390 variant for smp_call_function_mask(). The
implementation is pretty straight forward using the wrapper
__smp_call_function_map() which already takes a cpumask_t argument.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch removes TOPDIR from arch/s390/kernel/Makefile.
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the NOTES and BUG_TABLE section in the linker script to the
read-only sections right after the text section.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch fixes a problem with the following scenario:
1. Linux booted from DASD "A"
2. Reboot from DASD "B" using "/sys/firmware/reipl/ccw/device"
3. Reboot DASD "B"
Without this patch in step 3 on newer s390 systems under LPAR instead of
DASD "B", DASD "A" will be booted. The reason is that in step 2 we use CCW
reipl and in step 3 we use DIAG308 (subcode 3) reipl. DIAG308 does not
notice the CCW reipl and still thinks that it has to reboot DASD "A".
Before applying this fix, ensure to have MCF RJ9967101E or z9 GA3 base driver
installed.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The sclp ipl information has not been initialized. Therefore the ipl loadparm
and the "has_dump" flag have not been set correctly.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
No need to preallocate the per cpu lowcores and stacks.
Savings are 28-32k per offline cpu.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In case of a kernel panic it is currently possible to specify that a dump
should be created, the system should be rebooted or stopped. Virtual sysfs
files under the directory /sys/firmware/ are used for that configuration.
In addition to that, there are kernel parameters 'vmhalt', 'vmpoff'
and 'vmpanic', which can be used to specify z/VM commands, which are
automatically executed in case of halt, power off or a kernel panic.
This patch combines both functionalities and allows to specify the z/VM CP
commands also via sysfs attributes. In addition to that, it enhances the
existing handling of shutdown triggers (e.g. halt or panic) and associated
shutdown actions (e.g. dump or reipl) and makes it more flexible.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
It caused only a lot of confusion. From now on cpu hotplug of up to
NR_CPUS will work by default. If somebody wants to limit that then
the possible_cpus parameter can be used.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Align everything to MAX_ORDER so we can get rid of the extra checks.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Also print PREEMPT and/or SMP if the kernel was configured that way.
Makes s390 look a bit more like other architectures.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently the vmalloc area starts at a dynamic address depending on
the memory size. There was also an 8MB security hole after the
physical memory to catch out-of-bounds accesses.
We can simplify the code by putting the vmalloc area explicitely at
the top of the kernel mapping and setting the vmalloc size to a fixed
value of 128MB/128GB for 31bit/64bit systems. Part of the vmalloc
area will be used for the vmem_map. This leaves an area of 96MB/1GB
for normal vmalloc allocations.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The clear-by-asce operation of the idte instruction gets an asce
(address-space-control-element) as argument to specify which TLBs
need to get flushed. The current code passes a plain pointer to
the start of the pgd without the additional bits which would make
the pointer an asce. The current machines don't mind the difference
but a future model might want to use the designation type control
bits in the asce as a filter for the TLBs to flush.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
