Add missing multithreading fields of SYSIB 1.2.2 (Basic-Machine CPUs)
to the output of /proc/sysinfo.
Also use bitfields for SYSIB 2.2.2 to simplify the C code a bit.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use CONFIG_TOPOLOGY which selects CONFIG_SCHED_* all over the place to
reduce the random usage of the previous config options.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Replace the current semi-arbitrary distribution of inline assemblies:
- Inline assemblies used by CIO go into ioasm.h
- Data definitions used by inline assemblies go into cio.h
Beyond cleaning up the current structure this is also required for
use of tracepoints in inline assemblies introduced by a follow-on
patch.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Over time some machine flags got unused (e.g. MACHINE_FLAG_MVPG)
or are available on all 64bit systems (MACHINE_FLAG_CSP,
MACHINE_FLAG_IEEE) - let's remove them.
Reorder the other ones to match the order of the MACHINE_HAS_*
macros and renumber all bits to avoid holes.
Also fix the comment about where the flags are detected.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If configured for z13 assume the kernel makes use of the instructions
that are part of the load-and-zero-rightmost-byte facility and
load/store-on-condition facility 2.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
test_facility() can be optimized for bits which must be set anyway,
due to the check in head.S. This removes a couple of superfluous
runtime checks.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The facility lists contain a lot of bits which are not necessary to
run the kernel. Therefore remove them and keep only those bits which
are required for the kernel.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Modifying the architecture level set facility lists was always very
error prone. Given the numbering of the facility bits within the
Principles of Operation, where the most significant bit number is 0,
it happened a lot of times that wrong bits were set or cleared.
Therefore this patch adds a tool "gen_facilities" which generates
include/generated/facilites.h. The definition of the bits to be set
is contained within arch/s390/include/asm/facilities_src.h and can be
easily extended to e.g. also generate such lists for the KVM module.
The generated file looks like this:
#define FACILITIES_ALS _AC(0xc1006450f0040000,UL)
#define FACILITIES_ALS_DWORDS 1
The facility bits defined in this patch match 1:1 to the current masks
that can be found in head.S.
That is if the tool gets executed with -march=z990 then the generated
masks will equal the masks in head.S for CONFIG_MARCH_Z990.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Now that 31 bit support is gone, the assembler always knows about the
stfl instruction. Therefore lets use a readable mnemonic. Also remove
the not needed extable entry for the inline assembly and fix the
output constraint.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
It does not make sense to try to relinquish the time slice with diag 0x9c
to a CPU in a state that does not allow to schedule the CPU. The scenario
where this can happen is a CPU waiting in udelay/mdelay while holding a
spin-lock.
Add a CIF bit to tag a CPU in enabled wait and use it to detect that the
yield of a CPU will not be successful and skip the diagnose call.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
is_32bit_task() used to be helpful when we still had CONFIG_32BIT.
Since that is gone, it is nowadays identical to is_compat_task().
So remove it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When running under qemu with the default configuration (-nographic),
there is only a VT220 SCLP console, no line-mode SCLP console. Add
VT220 support to the early SCLP console so the user has a chance to
see critical error messages during early boot.
None of the existing users of _sclp_print_early() check the return
code. Instead of trying to come up with return code semantics when
printing to multiple consoles (any or all of which may fail), we just
drop the return code entirely.
Tested on z/VM (line mode console) and LPAR (VT220 and line mode
console). Tested on qemu/KVM with VT220 console and / or line mode
console.
Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
DMA addresses returned from map_page() are calculated by using an iommu
bitmap plus a start_dma offset. The size of this bitmap is based on the main
memory size. If we have more than (4 TB - start_dma) main memory, the DMA
address calculation will also produce addresses > 4 TB. Such addresses
cannot be inserted in the 3-level DMA page table, instead the entries
modulo 4 TB will be overwritten.
Fix this by restricting the iommu bitmap size to (4 TB - start_dma).
Also set zdev->end_dma to the actual end address of the usable
range, instead of the theoretical maximum as reported by the hardware,
which fixes a sanity check in dma_map() and also the IOMMU API domain
geometry aperture calculation.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce save_area_alloc(), save_area_boot_cpu(), save_area_add_regs()
and save_area_add_vxrs to deal with storing the CPU state in case of a
system dump. Remove struct save_area and save_area_ext, and create a new
struct save_area as a local definition to arch/s390/kernel/crash_dump.c.
Copy each individual field from the hardware status area to the save area,
storing the minimum of required data.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
To collect the CPU registers of the crashed system allocated a single
page with memblock_alloc_base and use it as a copy buffer. Replace the
stop-and-store-status sigp with a store-status-at-address sigp in
smp_save_dump_cpus() and smp_store_status(). In both cases the target
CPU is already stopped and store-status-at-address avoids the detour
via the absolute zero page.
For kexec simplify s390_reset_system and call store_status() before
the prefix register of the boot CPU has been set to zero. Use STPX
to store the prefix register and remove dump_prefix_page.
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce two copy functions for the memory of the dumped system,
copy_oldmem_kernel() to copy to the virtual kernel address space
and copy_oldmem_user() to copy to user space.
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The s390 architecture can store the CPU registers of the crashed system
after the kdump kernel has been started and this is the preferred way.
Remove the remaining code fragments that deal with storing CPU registers
while the crashed system is still active.
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
New versions of the SCSI dumper use the /dev/vmcore interface instead
of zcore mem. Remove the outdated interface.
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The /sys/kernel/debug/zcore/mem interface delivers the memory of the
old system with the CPU registers stored to the assigned locations in
each prefix page.
For the vector registers the prefix page of each CPU has an address of
a 1024 byte save area at 0x11b0. But the /sys/kernel/debug/zcore/mem
interface fails copy the vector registers saved at boot of the zfcpdump
kernel into the dump image.
Copy the saved vector registers of a CPU to the outout buffer if the
memory area that is read via /sys/kernel/debug/zcore/mem intersects
with the vector register save area of this CPU.
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit 1f6b83e5e4 ("s390: avoid z13 cache aliasing") checks for the
machine type to optimize address space randomization and zero page
allocation to avoid cache aliases.
This check might fail under a hypervisor with migration support.
z/VMs "Single System Image and Live Guest Relocation" facility will
"fake" the machine type of the oldest system in the group. For example
in a group of zEC12 and Z13 the guest appears to run on a zEC12
(architecture fencing within the relocation domain)
Remove the machine type detection and always use cache aliasing
rules that are known to work for all machines. These are the z13
aliasing rules.
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Allow to ipl from CCW based devices residing in any subchannel set.
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We use lazy allocation for translation table entries but don't handle
allocation (and other) failures during translation table updates.
Handle these failures and undo translation table updates when it's
meaningful.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Documentation/trace/tracepoints.txt states that the naming scheme
for tracepoints is "subsys_event" to avoid collisions. Rename
the 'diagnose' tracepoint to 's390_diagnose'.
Reported-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
handling.
PPC: Mostly bug fixes.
ARM: No big features, but many small fixes and prerequisites including:
- a number of fixes for the arch-timer
- introducing proper level-triggered semantics for the arch-timers
- a series of patches to synchronously halt a guest (prerequisite for
IRQ forwarding)
- some tracepoint improvements
- a tweak for the EL2 panic handlers
- some more VGIC cleanups getting rid of redundant state
x86: quite a few changes:
- support for VT-d posted interrupts (i.e. PCI devices can inject
interrupts directly into vCPUs). This introduces a new component (in
virt/lib/) that connects VFIO and KVM together. The same infrastructure
will be used for ARM interrupt forwarding as well.
- more Hyper-V features, though the main one Hyper-V synthetic interrupt
controller will have to wait for 4.5. These will let KVM expose Hyper-V
devices.
- nested virtualization now supports VPID (same as PCID but for vCPUs)
which makes it quite a bit faster
- for future hardware that supports NVDIMM, there is support for clflushopt,
clwb, pcommit
- support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in
userspace, which reduces the attack surface of the hypervisor
- obligatory smattering of SMM fixes
- on the guest side, stable scheduler clock support was rewritten to not
require help from the hypervisor.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"First batch of KVM changes for 4.4.
s390:
A bunch of fixes and optimizations for interrupt and time handling.
PPC:
Mostly bug fixes.
ARM:
No big features, but many small fixes and prerequisites including:
- a number of fixes for the arch-timer
- introducing proper level-triggered semantics for the arch-timers
- a series of patches to synchronously halt a guest (prerequisite
for IRQ forwarding)
- some tracepoint improvements
- a tweak for the EL2 panic handlers
- some more VGIC cleanups getting rid of redundant state
x86:
Quite a few changes:
- support for VT-d posted interrupts (i.e. PCI devices can inject
interrupts directly into vCPUs). This introduces a new
component (in virt/lib/) that connects VFIO and KVM together.
The same infrastructure will be used for ARM interrupt
forwarding as well.
- more Hyper-V features, though the main one Hyper-V synthetic
interrupt controller will have to wait for 4.5. These will let
KVM expose Hyper-V devices.
- nested virtualization now supports VPID (same as PCID but for
vCPUs) which makes it quite a bit faster
- for future hardware that supports NVDIMM, there is support for
clflushopt, clwb, pcommit
- support for "split irqchip", i.e. LAPIC in kernel +
IOAPIC/PIC/PIT in userspace, which reduces the attack surface of
the hypervisor
- obligatory smattering of SMM fixes
- on the guest side, stable scheduler clock support was rewritten
to not require help from the hypervisor"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits)
KVM: VMX: Fix commit which broke PML
KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0()
KVM: x86: allow RSM from 64-bit mode
KVM: VMX: fix SMEP and SMAP without EPT
KVM: x86: move kvm_set_irq_inatomic to legacy device assignment
KVM: device assignment: remove pointless #ifdefs
KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic
KVM: x86: zero apic_arb_prio on reset
drivers/hv: share Hyper-V SynIC constants with userspace
KVM: x86: handle SMBASE as physical address in RSM
KVM: x86: add read_phys to x86_emulate_ops
KVM: x86: removing unused variable
KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs
KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()
KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings
KVM: arm/arm64: Optimize away redundant LR tracking
KVM: s390: use simple switch statement as multiplexer
KVM: s390: drop useless newline in debugging data
KVM: s390: SCA must not cross page boundaries
KVM: arm: Do not indent the arguments of DECLARE_BITMAP
...
This time including:
* A new IOMMU driver for s390 pci devices
* Common dma-ops support based on iommu-api for ARM64. The plan is to
use this as a basis for ARM32 and hopefully other architectures as
well in the future.
* MSI support for ARM-SMMUv3
* Cleanups and dead code removal in the AMD IOMMU driver
* Better RMRR handling for the Intel VT-d driver
* Various other cleanups and small fixes
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Merge tag 'iommu-updates-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull iommu updates from Joerg Roedel:
"This time including:
- A new IOMMU driver for s390 pci devices
- Common dma-ops support based on iommu-api for ARM64. The plan is
to use this as a basis for ARM32 and hopefully other architectures
as well in the future.
- MSI support for ARM-SMMUv3
- Cleanups and dead code removal in the AMD IOMMU driver
- Better RMRR handling for the Intel VT-d driver
- Various other cleanups and small fixes"
* tag 'iommu-updates-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (41 commits)
iommu/vt-d: Fix return value check of parse_ioapics_under_ir()
iommu/vt-d: Propagate error-value from ir_parse_ioapic_hpet_scope()
iommu/vt-d: Adjust the return value of the parse_ioapics_under_ir
iommu: Move default domain allocation to iommu_group_get_for_dev()
iommu: Remove is_pci_dev() fall-back from iommu_group_get_for_dev
iommu/arm-smmu: Switch to device_group call-back
iommu/fsl: Convert to device_group call-back
iommu: Add device_group call-back to x86 iommu drivers
iommu: Add generic_device_group() function
iommu: Export and rename iommu_group_get_for_pci_dev()
iommu: Revive device_group iommu-ops call-back
iommu/amd: Remove find_last_devid_on_pci()
iommu/amd: Remove first/last_device handling
iommu/amd: Initialize amd_iommu_last_bdf for DEV_ALL
iommu/amd: Cleanup buffer allocation
iommu/amd: Remove cmd_buf_size and evt_buf_size from struct amd_iommu
iommu/amd: Align DTE flag definitions
iommu/amd: Remove old alias handling code
iommu/amd: Set alias DTE in do_attach/do_detach
iommu/amd: WARN when __[attach|detach]_device are called with irqs enabled
...
Includes a number of fixes for the arch-timer, introducing proper
level-triggered semantics for the arch-timers, a series of patches to
synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint
improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups
getting rid of redundant state, and finally a stylistic change that gets rid of
some ctags warnings.
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Merge tag 'kvm-arm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/ARM Changes for v4.4-rc1
Includes a number of fixes for the arch-timer, introducing proper
level-triggered semantics for the arch-timers, a series of patches to
synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint
improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups
getting rid of redundant state, and finally a stylistic change that gets rid of
some ctags warnings.
Conflicts:
arch/x86/include/asm/kvm_host.h
The external interrupts for runtime instrumentation buffer-full
and runtime instrumentation halted are unused and have no current
user. Remove the support and ignore the second parameter of the
s390_runtime_instr system call from now on.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove all the casts to and from the machine check interruption code.
This patch changes struct mci to a union, which contains an anonymous
structure with the already known bits and in addition an unsigned
long field, which contains the raw machine check interruption code.
This allows to simply assign and decoce the interruption code value
without the need for all those casts we had all the time.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The current disabled wait code stores register contents into their
save areas, however it is (at least) missing the new vector registers.
Given the fact that the whole exercise seems to be rather pointless
simply don't save any registers anymore.
In a "live" system it is always possible to inspect register contents,
and in case of a dump the register contents will be stored by the
dump mechanism.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With the removal of 31 bit code we can always assume that the epsw
instruction is available. Therefore use the __extract_psw() function
to disable and enable machine checks.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Some times it is useful for architecture implementations of KVM to know
when the VCPU thread is about to block or when it comes back from
blocking (arm/arm64 needs to know this to properly implement timers, for
example).
Therefore provide a generic architecture callback function in line with
what we do elsewhere for KVM generic-arch interactions.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Split the API and FPU type definitions into separate header files
similar to "x86/fpu: Rename fpu-internal.h to fpu/internal.h" (78f7f1e54b).
The new header files and their meaning are:
asm/fpu/types.h:
FPU related data types, needed for 'struct thread_struct' and
'struct task_struct'.
asm/fpu/api.h:
FPU related 'public' functions for other subsystems and device
drivers.
asm/fpu/internal.h:
FPU internal functions mainly used to convert
FPU register contents in signal handling.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
the kernel locks have aqcuire/release semantics. No operation done
after the lock can be "moved" before the lock and no operation before
the unlock can be moved after the unlock. But it is perfectly fine
that memory accesses which happen code wise after unlock are performed
within the critical section.
On s390x, reads are in-order with other reads (PoP section
"Storage-Operand Fetch References") and writes are in-order with
other writes (PoP section "Storage-Operand Store References"). Writes
are also in-order with reads to the same memory location (PoP section
"Storage-Operand Store References"). To other CPUs (and the channel
subsystem), reads additionally appear to be performed prior to reads or
writes that happen after them in the conceptual sequence (PoP section
"Relation between Operand Accesses").
So at least as observed by other CPUs and the channel subsystem, reads
inside the critical sections will not happen after unlock (and writes
are in-order anyway). That's exactly what we need for "RELEASE
operations" (memory-barriers.txt): "It guarantees that all memory
operations before the RELEASE operation will appear to happen before the
RELEASE operation with respect to the other components of the system."
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com>
[cross-reading and lot of improvements for the patch description]
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The first level machine check handler for etr and stp machine checks may
call queue_work() while in nmi context. This may deadlock e.g. if the
machine check happened when the interrupted context did hold a lock, that
also will be acquired by queue_work().
Therefore split etr and stp machine check handling into first and second
level handling. The second level handling will then issue the queue_work()
call in process context which avoids the potential deadlock.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With the removal of 31 bit support a couple of defines became unused.
Remove them.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
For some unknown reason the mcck_interruption_code field is defined
as array of two 32 bit values. Given that this actually is a 64 bit
field according to the architecture, change the type to u64.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The defines that are used in entry.S have been partially converted to
use the _BITUL macro (setup.h). This patch converts the rest.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The cpu flags and pt_regs flags fields are each 64 bits in size. A flag can
be set with helper functions like set_cpu_flags().
These functions create a mask using "1U << flag". This doesn't work if flag
is larger than 31, since 1U << 32 == 0.
So fix this in case we ever will have such flag numbers.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When using systemtap it was observed that our udelay implementation is
rather suboptimal if being called from a kprobe handler installed by
systemtap.
The problem observed when a kprobe was installed on lock_acquired().
When the probe was hit the kprobe handler did call udelay, which set
up an (internal) timer and reenabled interrupts (only the clock comparator
interrupt) and waited for the interrupt.
This is an optimization to avoid that the cpu is busy looping while waiting
that enough time passes. The problem is that the interrupt handler still
does call irq_enter()/irq_exit() which then again can lead to a deadlock,
since some accounting functions may take locks as well.
If one of these locks is the same, which caused lock_acquired() to be
called, we have a nice deadlock.
This patch reworks the udelay code for the interrupts disabled case to
immediately leave the low level interrupt handler when the clock
comparator interrupt happens. That way no C code is being called and the
deadlock cannot happen anymore.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The program parameter can be used to mark hardware samples with
some token. Previously, it was used to mark guest samples only.
Improve the program parameter doubleword by combining two parts,
the leftmost LPP part and the rightmost PID part. Set the PID
part for processes by using the task PID.
To distinguish host and guest samples for the kernel (PID part
is zero), the guest must always set the program paramater to a
non-zero value. Use the leftmost bit in the LPP part of the
program parameter to be able to detect guest kernel samples.
[brueckner@linux.vnet.ibm.com]: Split __LC_CURRENT and introduced
__LC_LPP. Corrected __LC_CURRENT users and adjusted assembler parts.
And updated the commit message accordingly.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Various functions in entry.S perform test-under-mask instructions
to test for particular bits in memory. Because test-under-mask uses
a mask value of one byte, the mask value and the offset into the
memory must be calculated manually. This easily introduces errors
and is hard to review and read.
Introduce the TSTMSK assembler macro to specify a mask constant and
let the macro calculate the offset and the byte mask to generate a
test-under-mask instruction. The benefit is that existing symbolic
constants can now be used for tests. Also the macro checks for
zero mask values and mask values that consist of multiple bytes.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Previously, the init task did not have an allocated FPU save area and
saving an FPU state was not possible. Now if the vector extension is
always enabled, provide a static FPU save area to save FPU states of
vector instructions that can be executed quite early.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If the kernel detects that the s390 hardware supports the vector
facility, it is enabled by default at an early stage. To force
it off, use the novx kernel parameter. Note that there is a small
time window, where the vector facility is enabled before it is
forced to be off.
With enabling the vector facility by default, the FPU save and
restore functions can be improved. They do not longer require
to manage expensive control register updates to enable or disable
the vector enablement control for particular processes.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The call to pgste_set_key in ptep_set_access_flags can be avoided
if the old pte is found to be valid at the time the new access
rights are set. The function that created the old, valid pte already
completed the required storage key operation.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The principles of operation states reads are in order, writes are in
order, writes can be reordered after reads, but no reads can be
reordered after writes.
The atomic and bitops variantes for z196 use the interlocked-access
facility instructions with a memory barrier before and after the
instruction. Because of the memory ordering the first barrier is
unnecessary and can be removed.
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
To be able to analyse problems in regard to hypervisor overhead
add a tracepoing for diagnose calls. It reports the number of
the diagnose issued, e.g.
sshd-1385 [002] .... 42.701431: diagnose: nr=0x9c
<idle>-0 [001] ..s. 43.587528: diagnose: nr=0x9c
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose
calls have been done by each CPU in the system.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The generic implementation for test_and_set_bit_lock in include/asm-generic
uses the standard test_and_set_bit operation. This is done with either a
'csg' or a 'loag' instruction. For both version the cache line is fetched
exclusively, even if the bit is already set. The result is an increase in
cache traffic, for a contented lock this is a bad idea.
Acked-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
