Standby memory detected with the sclp interface gets always registered
with add_memory calls without considering the limitationt that the
"mem=" kernel paramater implies.
So fix this and only register standby memory that is below the specified
limit.
This fixes zfcpdump since it uses "mem=32M". In case there is appr.
2GB standby memory present all of usable memory would be used for the
struct pages needed for standby memory.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The extract cpu time instruction (ectg) instruction allows the user
process to get the current thread cputime without calling into the
kernel. The code that uses the instruction needs to switch to the
access registers mode to get access to the per-cpu info page that
contains the two base values that are needed to calculate the current
cputime from the CPU timer with the ectg instruction.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch sets the default console device for s390.
The console= kernel parameter can be still used to switch the preferred
console to some other device. In that case, console messages are also
printed on the default console device (ttyS0).
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add the machine types for z9-bc, z10-ec and z10-bc to the elf_platform
detection in setup_hwcaps.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
stfle will be needed by the ap_bus module to figure out wether the AP
queue adapter interruption facility is installed.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
add_active_range() expects start_pfn + size as end_pfn value, i.e. not
the pfn of the last page frame but the one behind that.
We used the pfn of the last page frame so far, which can lead to a
BUG_ON in move_freepages(), when the kernelcore parameter is specified
(page_zone(start_page) != page_zone(end_page)).
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch enables virtio_console as the default console on kvm for
s390. We currently use the same notify hack as lguest for early
console output. I will try to address this for lguest and s390 later.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Most likely it is broken anyway because of the changes in memory
detection. Since we can't test it and there are probably better ways
that using a P390 card, remove support for it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move memory detection code to own file and also simplify it.
Also add an interface which can be called at any time to get the
current memory layout. This interface is needed by our kernel
internal system dumper.
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Michael Holzheu <holzheu@de.ibm.com>
Cc: Frank Munzert <munzert@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Now it is possible to specify additional kernel parameters on the IPL
command line using the IPL PARM option.
If the Linux system is already running, the new reipl sysfs attribute
'parm' can be used to change kernel parameters for the next reboot.
Examples:
IPL C PARM dasd=1234 root=/dev/dasda1
IPL 1234 PARM savesys=mylnxnss
echo "init=/bin/bash" > /sys/firmware/reipl/ccw/parm
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Using the ipldelay kernel parameter leads to a crash at IPL time.
Since this is broken since a long time it looks like nobody is using
it anymore. So remove it instead of fixing it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This adds hugetlbfs support on System z, using both hardware large page
support if available and software large page emulation on older hardware.
Shared (large) page tables are implemented in software emulation mode,
by using page->index of the first tail page from a compound large page
to store page table information.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
From: Heiko Carstens <heiko.carstens@de.ibm.com>
From: Carsten Otte <cotte@de.ibm.com>
This lets us use defines for the magic bits in machine flags instead
of using plain numbers all over the place.
In addition on newer machines features/facilities are indicated by the
result of the stfl instruction. So we use these bits instead of trying
to execute new instructions and check wether we get an exception or
not.
Also the mvpg instruction is always available when in zArch mode,
whereas the idte instruction is only available in zArch mode. This
results in some minor optimizations.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds functionality to detect if the kernel runs under the KVM
hypervisor. A macro MACHINE_IS_KVM is exported for device drivers. This
allows drivers to skip device detection if the systems runs non-virtualized.
We also define a preferred console to avoid having the ttyS0, which is a line
mode only console.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The SIE instruction on s390 uses the 2nd half of the page table page to
virtualize the storage keys of a guest. This patch offers the s390_enable_sie
function, which reorganizes the page tables of a single-threaded process to
reserve space in the page table:
s390_enable_sie makes sure that the process is single threaded and then uses
dup_mm to create a new mm with reorganized page tables. The old mm is freed
and the process has now a page status extended field after every page table.
Code that wants to exploit pgstes should SELECT CONFIG_PGSTE.
This patch has a small common code hit, namely making dup_mm non-static.
Edit (Carsten): I've modified Martin's patch, following Jeremy Fitzhardinge's
review feedback. Now we do have the prototype for dup_mm in
include/linux/sched.h. Following Martin's suggestion, s390_enable_sie() does now
call task_lock() to prevent race against ptrace modification of mm_users.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@qumranet.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>
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 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>
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>
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>
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>
Add a new interface so that cpus can be put into standby state and
configured state.
Only offline cpus can be put into standby state or configured state.
For that the new percpu sysfs attribute "configure" must be used.
To put a cpu in standby state a "0" must be written to the attribute.
In order to switch it into configured state a "1" must be written to
the attribute.
Only cpus in configured state can be brought online.
In addition this patch introduces a static mapping of physical to
logical cpus. As a result only the sysfs directories of present cpus
will be created. To scan for new cpus the new sysfs attribute "rescan"
must be used.
Writing to /sys/devices/system/cpu/rescan will trigger a rescan of
cpus and will create directories for new cpus.
On IPL only configured cpus will be used. And on reboot/shutdown all
cpus will remain in their current state (configured/standby).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In case of TRACE_IRQFLAGS the restore psw masks will not be
initialized if noexec is turned on. This will lead to an
immediate system crash.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Current support for TRACE_IRQFLAGS and lockdep_sys_exit is broken.
IRQ flag tracing is broken for program checks. Even worse is that
the newly introduced calls to lockdep_sys_exit are in the critical
section code which is not supposed to call any C functions. In
addition the checks if locks are still held are also done when
returning to kernel code which is broken as well.
Fix all this by disabling interrupts and machine checks at the
exit paths and then do the appropriate checks and calls.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When doing an magic sysrq reboot on s390 the following bug message
appears:
SysRq : Resetting
BUG: sleeping function called from invalid context at include/asm/semaphore.h:61
in_atomic():1, irqs_disabled():0
07000000004002a8 000000000fe6bc48 0000000000000002 0000000000000000
000000000fe6bce8 000000000fe6bc60 000000000fe6bc60 000000000012a79a
0000000000000000 07000000004002a8 0000000000000006 0000000000000000
0000000000000000 000000000fe6bc48 000000000000000d 000000000fe6bcb8
00000000004000c8 0000000000103234 000000000fe6bc48 000000000fe6bc90
Call Trace:
(¬<00000000001031b2>| show_trace+0x12e/0x148)
¬<000000000011ffca>| __might_sleep+0x10a/0x118
¬<0000000000129fba>| acquire_console_sem+0x92/0xf4
¬<000000000012a2ca>| console_unblank+0xc2/0xc8
¬<0000000000107bb4>| machine_restart+0x54/0x6c
¬<000000000028e806>| sysrq_handle_reboot+0x26/0x30
¬<000000000028e52a>| __handle_sysrq+0xa6/0x180
¬<0000000000140134>| run_workqueue+0xcc/0x18c
¬<000000000014029a>| worker_thread+0xa6/0x108
¬<00000000001458e4>| kthread+0x64/0x9c
¬<0000000000106f0e>| kernel_thread_starter+0x6/0xc
¬<0000000000106f08>| kernel_thread_starter+0x0/0xc
The only reason for doing a console_unblank on s390 is to flush the
log buffer. We have to check for in_atomic before doing a
console_unblank as the console is otherwise filled with an unrelated
bug message.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When appending the 'cio_ignore' kernel parameter to the command line, a blank
has to be inserted in order to separate 'cio_ignore' from the preceding kernel
parameters.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the __cpuinit instead of __devinit section annotations for code
that deals with cpu hotplug. In addition add some more annotations on
functions that have been left out so far.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Commit c1821c2e97 introduced the
uaccess structure that is used to select the correct set of user
copy functions for the different execution modes (standard vs.
noexec vs. z9 optimized user copy). The uaccess symbol is exported
with EXPORT_SYMBOL_GPL. This breaks all non-gpl modules that use
user copy. To make them work again change the export to
EXPORT_SYMBOL.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390 machines provide hardware support for creating Linux dumps on SCSI
disks. For creating a dump a special purpose dump Linux is used. The first
32 MB of memory are saved by the hardware before the dump Linux is
booted. Via an SCLP interface, the saved memory can be accessed from
Linux. This patch exports memory and registers of the crashed Linux to
userspace via a debugfs file. For more information refer to
Documentation/s390/zfcpdump.txt, which is included in this patch.
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>
With CONFIG_SHARED_KERNEL the kernel text segment that might be in a
read only memory sections starts at 1MB. Memory between 0x12000 and
0x100000 is unused then. Free this, so we have appr. an extra MB
of memory available.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Setup.h has been misused for ipl related stuff in the past. We now move
everything, which has to do with ipl and reipl to a new header file named
"ipl.h".
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Replace two stidp inline assemblies with one global implementation.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Hopefully this will make it more maintainable and less error prone.
Code makes use of search_exception_tables(). Since it calls this
function before the kernel exeception table is sorted, there is an
early call to sort_main_extable().
This way it's easy to use the already present infrastructure of fixup
sections. Also this would allows to easily convert the rest of
head[31|64].S into C code.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Preset the bogomips number to the cpu capacity value reported by
store system information in SYSIB 1.2.2. This value is constant
for a particular machine model and can be used to determine
relative performance differences between machines.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support to boot from a named saved segment (NSS).
Signed-off-by: Hongjie Yang <hongjie@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This provides a noexec protection on s390 hardware. Our hardware does
not have any bits left in the pte for a hw noexec bit, so this is a
different approach using shadow page tables and a special addressing
mode that allows separate address spaces for code and data.
As a special feature of our "secondary-space" addressing mode, separate
page tables can be specified for the translation of data addresses
(storage operands) and instruction addresses. The shadow page table is
used for the instruction addresses and the standard page table for the
data addresses.
The shadow page table is linked to the standard page table by a pointer
in page->lru.next of the struct page corresponding to the page that
contains the standard page table (since page->private is not really
private with the pte_lock and the page table pages are not in the LRU
list).
Depending on the software bits of a pte, it is either inserted into
both page tables or just into the standard (data) page table. Pages of
a vma that does not have the VM_EXEC bit set get mapped only in the
data address space. Any try to execute code on such a page will cause a
page translation exception. The standard reaction to this is a SIGSEGV
with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn)
and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the
kernel to the signal stack frame. Unfortunately, the signal return
mechanism cannot be modified to use an SA_RESTORER because the
exception unwinding code depends on the system call opcode stored
behind the signal stack frame.
This feature requires that user space is executed in secondary-space
mode and the kernel in home-space mode, which means that the addressing
modes need to be switched and that the noexec protection only works
for user space.
After switching the addressing modes, we cannot use the mvcp/mvcs
instructions anymore to copy between kernel and user space. A new
mvcos instruction has been added to the z9 EC/BC hardware which allows
to copy between arbitrary address spaces, but on older hardware the
page tables need to be walked manually.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
