On each machine check all registers are revalidated. The save area for
the clock comparator however only contains the upper most seven bytes
of the former contents, if valid.
Therefore the machine check handler uses a store clock instruction to
get the current time and writes that to the clock comparator register
which in turn will generate an immediate timer interrupt.
However within the lowcore the expected time of the next timer
interrupt is stored. If the interrupt happens before that time the
handler won't be called. In turn the clock comparator won't be
reprogrammed and therefore the interrupt condition stays pending which
causes an interrupt loop until the expected time is reached.
On NOHZ machines this can result in unresponsive machines since the
time of the next expected interrupted can be a couple of days in the
future.
To fix this just revalidate the clock comparator register with the
expected value.
In addition the special handling for udelay must be changed as well.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Analog to git commit 737480a0d5
fix the return address of subsequent kretprobes when multiple
kretprobes are set on the same function.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Execute the kprobe exception and fault handler with interrupts disabled.
To disable the interrupts only while a single step is in progress is not
good enough, a kprobe from interrupt context while another kprobe is
handled can confuse the internal house keeping.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Provide the devmem_is_allowed() routine to restrict access to
kernel memory from userspace.
Set the CONFIG_STRICT_DEVMEM config option to switch on checking.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The check for the _PAGE_RO bit in get_user_pages_fast for write==1 is
the wrong way around. It must not be set for the fast path.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix kprobes after git commit 1e54622e04
broke it. The kprobe_handler is now called with interrupts in the state
at the time of the breakpoint. The single step of the replaced instruction
is done with interrupts off which makes it necessary to enable and disable
the interupts in the kprobes code.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The BIODASDSNID ioctl executes a 'Sense Path Group ID'
command on a DASD ECKD device. The returned path group data
allows user space programs to determine path state and
path group ID of the channel paths to the device.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Select HAVE_C_RECORDMCOUNT for the fast C version of recordmcount.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The CLOCK_* defines in asm-offsets.c are only used for the vdso code
however in the meantime they cause other trouble.
Just rename them to get permanently rid of this:
In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/asm-offsets.h:1:0,
from arch/s390/mm/fault.c:33:
include/generated/asm-offsets.h:53:0: warning: "CLOCK_REALTIME" redefined
include/linux/time.h:286:0: note: this is the location of the previous definition
include/generated/asm-offsets.h:54:0: warning: "CLOCK_MONOTONIC" redefined
include/linux/time.h:287:0: note: this is the location of the previous definition
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix the following two error handling bugs in hypfs_diag_init():
* No need for calling diag204_free_buffer()
* Initialize name table only in case of LPAR and prevent error message
on non-LPAR systems.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix cpu masks for 'topology=off' case. Folding of the scheduling domains
happen in such a way that everything belongs to the MC domain instead
of the CPU doimain.
This should fix a performance regression introduced with
eafd2b6d "[S390] topology: use default MC domain initializer" and also
makes sure we have the same behavious as if CONFIG_SCHED_MC was not
selected at all.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This allows us to easily check for performance differences seen with
!CONFIG_SCHED_MC and topology=off.
Actually there shouldn't be any (besides a small overhead because of
additional code).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add machine type number to code generation options. Also clean up and
shorten quite a lot of help texts with respect to machine type and
architecture terminology.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add machine type for zEnterprise 196 to elf platform detection.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The taskstats interface uses microsecond granularity for the user and
system time values. The conversion from cputime to the taskstats values
uses the cputime_to_msecs primitive which effectively limits the
granularity to milliseconds. Add the cputime_to_usecs primitive for
architectures that have better, more precise CPU time values. Remove
cputime_to_msecs primitive because there are no more users left.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Luck Tony <tony.luck@intel.com>
Cc: Shailabh Nagar <nagar1234@in.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shailabh Nagar <nagar@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since we no longer need to provide KM_type, the whole pte_*map_nested()
API is now redundant, remove it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Export the cpu configuration topology via sysinfo. Two new lines are
introduced:
CPU Topology HW: 0 0 0 4 6 4
CPU Topology SW: 0 0 0 0 4 24
The HW line describes the cpu topology nesting levels when the maximum
nesting level is used to get the corresponding SYSIB.
The SW line describes what Linux is actually using. In this case it
supports only two levels (CONFIG_SCHED_BOOK off) and therefore the
hardware folded the two lower levels in the SYSIB response block.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the topology sysinfo SYSIB definitions to the proper place in
asm/sysinfo.h where they should be.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move cpu topology facility detection to early setup code where it
should be.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Store the facility list once at system startup with stfl/stfle and
reuse the result for all facility tests.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Enable PFPO, floating point extension, distinct-operands,
fast-BCR-serialization, high-word, interlocked-access, load/store-
on-condition, and population-count facilities for guests.
(bits 37, 44 and 45).
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit 050eef364a
[S390] fix tlb flushing vs. concurrent /proc accesses
broke KVM on s390x. On every schedule a
Badness at include/asm/mmu_context.h:83 appears. s390_enable_sie
replaces the mm on the __running__ task, therefore, we have to
increase the attach count of the new mm.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Switch default value of the kernel parameter 'topology' from off to on.
Various performance measurements have finally shown that there are no
(known) regressions anywhere.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Up to now print_cpu_info() uses the cpu address stored in it's local
lowcore to print a message to the console. The cpu address in the
lowcore is (in this case) however not the physical cpu address of the
local cpu. It's the address of the cpu that issued the sigp restart
which started the local cpu.
Fix this by using the store cpu address instruction instead.
It's not that anybody really cares since this is broken since more than
ten years...
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The ieee_instruction_pointer can not be read from user space anymore
since git commit 613e1def6b, the ptrace
interface always returns zero. Remove it from the thread_struct. It
is still present in the user_regs_struct for compatability reasons.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Do the setup of the stack overflow argument for the sixth system
call parameter right before the branch to the system call function.
That simplifies the system call parameter access code.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The store-cpu-id instruction has a minimum alignment of 8. Reflect
that in the definition of struct cpuid.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Read external interrupts parameters from the lowcore in the first
level interrupt handler in entry[64].S.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Read all required fields for program checks from the lowcore in the
first level interrupt handler in entry[64].S. If the context that
caused the fault was enabled for interrupts we can now re-enable the
irqs in entry[64].S.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
All architectures besides s390 have pte_mkhuge() defined in pgtable.h.
So move the function to pgtable.h on s390 as well.
Fixes a compile error introduced with "hugetlb: hugepage migration core"
in linux-next which only happens on s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Raise SIGBUS with a siginfo structure. Deliver BUS_ADRERR as si_code and
the address of the fault in the si_addr field.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds a notification mechanism to inform ccw drivers
about changes to channel paths, which occured while the device
is online.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When the cmm module is compiled into the kernel it will crash when
writing to the R/O data section.
Reason is the lower to upper case conversion of the "sender" module
parameter which ignored the fact that the pointer is preinitialized.
Introduced with 41b42876 "cmm, smsgiucv_app: convert sender to
uppercase"
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
schedule() makes sure that prev != next before calling switch_to().
Therefore remove the redundant check.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If the previous task was a kernel thread there is no need to save the
contents of the fpu and access registers since they aren't used in
kernel mode.
For the same reason it is not necessary to restore these registers if
the next task is a kernel thread.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a kernel config option for the IBM zEnterprise 196. This will
produce faster code on newer compilers using the -march=z196 option.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Display machine capacity adjustment indicator and capacity
change reason if available in /proc/sysinfo.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Improve performance of the sske operation by using the nonquiescing
variant if the affected page has no mappings established. On machines
with no support for the new sske variant the mask bit will be ignored.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the store indication bit in the translation exception code on
page faults to avoid the protection faults that immediatly follow
the page fault if the access has been a write.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There is no difference if cpu_die is called from enabled or disabled
context. Except that the fast_gup code might be called via
cpu_die -> idle_task_exit -> __mm_drop -> crst_table_free. Which in
turn grabs and releases a spinlock using the _bh ops, which is not
allowed in irq disabled context, since spin_unlock_bh will
unconditionally enable interrupts again.
To get rid of the warning emitted by the softirq code just move the
code to enabled context.
In this case this doesn't fix a bug, we just get rid of a warning.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Set ARCH_HAS_SG_CHAIN for scatter lists on s390. Without this flag the
SCSI code limits the maximum number of segments, so set it to make
proper use of the FCP channel hardware.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introducing this Kbuild file allow us to:
make arch/s390/
And thus building all the core part of s390.
Same as on other architectures.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If the zero page is mapped to virtual user space addresses that differ
only in bit 2^12 or 2^13 we get L1 cache synonyms which can affect
performance. Follow the mips model and use multiple zero pages to avoid
the synonyms.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Heiko Carstens