For the 8xx, PVR values defined in arch/powerpc/include/asm/reg.h
are nowhere used.
Remove all defines and add PVR_8xx
Use it in arch/powerpc/kernel/cputable.c
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Two config options exist to define powerpc MPC8xx:
* CONFIG_PPC_8xx
* CONFIG_8xx
arch/powerpc/platforms/Kconfig.cputype has contained the following
comment about CONFIG_8xx item for some years:
"# this is temp to handle compat with arch=ppc"
arch/powerpc is now the only place with remaining use of
CONFIG_8xx: get rid of them.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The 8xx cannot access the TBL and TBU registers using mfspr/mtspr
It must be accessed using mftb/mftbu
Due to this, there is a number of places with #ifdef CONFIG_8xx
This patch defines new macros MFTBL(x) and MFTBU(x) on the same model
as MFTB(x) and tries to make use of them as much as possible.
In arch/powerpc/include/asm/timex.h, we also remove the ifdef
for the asm() operands as the compiler doesn't mind unused operands
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Since commit aa42c69c67 ("[POWERPC] Add support for FP emulation
for the e300c2 core"), program_check_exception() can be called for
math emulation. In that case, 'reason' is 0.
On the 8xx, there is a Software Emulation interrupt which is
called for all unimplemented and illegal instructions. This
interrupt calls SoftwareEmulation() which does almost the
same as program_check_exception() called with reason = 0.
The Software Emulation interrupt sets all reason bits to 0,
it is therefore possible to call program_check_exception()
directly from the interrupt handler.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In the same spirit as what was done for 4xx and 44x, move
the 8xx machine check into platforms/8xx
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we open code the reason codes for program checks. Instead use
the existing SRR1 defines.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We already have mce.c which is built for 64bit and contains other parts
of the machine check code, so move these bits in there too.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Make it clear that the fallback version of machine_check_generic() is
only used on 32-bit configs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
get_mc_reason() no longer provides (if it ever really did) any
meaningful abstraction, so remove it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that we have 4xx platform directory we can move the 4xx machine
check handler in there. Again we drop get_mc_reason() and replace it
with regs->dsisr directly (which is actually SPRN_ESR).
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We have several 44x machine check handlers defined in traps.c. It would
be preferable if they were split out with the platforms that use them.
Do that.
In the process, drop get_mc_reason() and instead just open code the
lookup of reason from regs->dsisr. This avoids a pointless layer of
abstraction.
We know to use regs->dsisr because 44x enables BOOKE which enables
PPC_ADV_DEBUG_REGS, and FSL_BOOKE is not enabled on 44x builds.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we build the 47x cputable entries even when CONFIG_PPC_47x is
disabled. That means a kernel built without CONFIG_PPC_47x will claim to
support a 47x CPU and start booting, only to break somewhere later
because it doesn't have 47x support compiled in.
So guard the 47x cputable entries with CONFIG_PPC_47x. Note that this is
inside the #ifdef CONFIG_44x section, because 47x depends on 44x.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds an irq counter for the watchdog soft-NMI. This interrupt
only fires when interrupts are soft-disabled, so it will not
increment much even when the watchdog is running. However it's
useful for debugging and sanity checking.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The powerpc kernel/watchdog.o should be built when HARDLOCKUP_DETECTOR
and HAVE_HARDLOCKUP_DETECTOR_ARCH are both selected. If only the former
is selected, then the generic perf watchdog has been selected.
To simplify this check, introduce a new Kconfig symbol PPC_WATCHDOG that
depends on both. This Kconfig option means the powerpc specific
watchdog is enabled.
Without this patch, Book3E will attempt to build the powerpc watchdog.
Fixes: 2104180a53 ("powerpc/64s: implement arch-specific hardlockup watchdog")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On 64-bit Book3s, when we're in HV mode, we have already counted the
machine check exception in machine_check_early().
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use IS_ENABLED() rather than an #ifdef]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
binutils >= 2.26 now warns about misuse of register expressions in
assembler operands that are actually literals, for example:
arch/powerpc/kernel/entry_64.S:535: Warning: invalid register expression
In practice these are almost all uses of r0 that should just be a
literal 0.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
[mpe: Mention r0 is almost always the culprit, fold in purgatory change]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When CPUs start and stop the watchdog, they manipulate shared data
that is normally protected by the lock. Other CPUs can be running
concurrently at this time, so it's a good idea to use locking here
to be on the safe side.
Remove the barrier which is undocumented and didn't do anything.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the SMP detector finds other CPUs stuck, it iterates over
them and marks them as stuck. This pulls them out of the pending
mask and allows the detector to continue with remaining good
CPUs (if nmi_watchdog=panic is not enabled).
The code to dothat was buggy because when setting a CPU stuck,
if the pending mask became empty, it resets it to keep the
watchdog running. However the iterator will continue to run
over the new pending mask and mark remaining good CPUs sas stuck.
Fix this by doing it with cpumask bitwise operations.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the watchdog decides to panic, it takes the lock and double
checks everything (to avoid races with the CPU being unstuck or
panic()ed by something else).
The exit label was misplaced and would result in all-CPUs backtrace
and watchdog panic even in the case that the condition was found to be
resolved.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Some code can go into a tight loop calling touch_nmi_watchdog (e.g.,
stop_machine CPU hotplug code). This can cause contention on watchdog
locks particularly if all CPUs with watchdog enabled are spinning in
the loops.
Avoid this storm of activity by running the watchdog timer callback
from this path if we have exceeded the timer period since it was last
run.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- Hard-disable interrupts before taking the lock, which prevents
soft-NMI re-entrancy and therefore can prevent deadlocks.
- Use raw_ variants of local_irq_disable to avoid irq debugging.
- When the lock is contended, spin at low SMT priority, using
loads only, and with interrupts enabled (where possible).
Some stalls have been noticed at high loads that go away with improved
locking. There should not be so much locking contention in the first
place (which is addressed in a subsequent patch), but locking should
still be improved.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the NMI IPI lock is contended, spin at low SMT priority, using
loads only, and with interrupts enabled (where possible). This
improves behaviour under high contention (e.g., a system crash when
a number of CPUs are trying to enter the debugger).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit d300627c6a ("powerpc/6xx: Handle DABR match before calling
do_page_fault") breaks non 6xx platforms.
Failed to execute /init (error -14)
Starting init: /bin/sh exists but couldn't execute it (error -14)
Kernel panic - not syncing: No working init found. Try passing init= ...
CPU: 0 PID: 1 Comm: init Not tainted 4.13.0-rc3-s3k-dev-00143-g7aa62e972a56 #56
Call Trace:
panic+0x108/0x250 (unreliable)
rootfs_mount+0x0/0x58
ret_from_kernel_thread+0x5c/0x64
Rebooting in 180 seconds..
This is because in handle_page_fault(), the call to do_page_fault() has been
mistakenly enclosed inside an #ifdef CONFIG_6xx
Fixes: d300627c6a ("powerpc/6xx: Handle DABR match before calling do_page_fault")
Brown-paper-bag-to-be-worn-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If the decrementer wraps again and de-asserts the decrementer
exception while hard-disabled, __check_irq_replay() has a test to
notice the wrap when interrupts are re-enabled.
The decrementer check must be done when clearing the PACA_IRQ_HARD_DIS
flag, not when the PACA_IRQ_DEC flag is tested. Previously this worked
because the decrementer interrupt was always the first one checked
after clearing the hard disable flag, but HMI check was moved ahead of
that, which introduced this bug.
This can cause a missed decrementer interrupt if we soft-disable
interrupts then take an HMI which is recorded in irq_happened, then
hard-disable interrupts for > 4s to wrap the decrementer.
Fixes: e0e0d6b739 ("powerpc/64: Replay hypervisor maintenance interrupt first")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
A solution is to set then clear MMCRA[60] after wake from state-loss
idle. MMCRA[60] is a non-architected bit, see the user manual for
details.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This uses the newly defined constants for this rather than open-coded
numbers. There is a side effect on 64-bit which is to pass through
some of the new P9 bits which we didn't before.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We test a number of bits from DSISR/SRR1 before deciding
to call hash_page(). If any of these is set, we go directly
to do_page_fault() as the bit indicate a fault that needs
to be handled there (no hashing needed).
This updates the current open-coded masks to use the new
DSISR definitions.
This *does* change the masks actually used in two ways:
- We used to test various bits that were defined as "always 0"
in the architecture and could be repurposed for something
else. From now on, we just ignore such bits.
- We were missing some new bits defined on P9
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On legacy 6xx 32-bit procesors, we checked for the DABR match bit
in DSISR from do_page_fault(), in the middle of a pile of ifdef's
because all other CPU types do it in assembly prior to calling
do_page_fault. Fix that.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Add #ifdef CONFIG_6xx]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
By filtering the relevant SRR1 bits in the assembly rather than
in do_page_fault() itself, we avoid a conditional branch (since we
already come from different path for data and instruction faults).
This will allow more simplifications later
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Replace the __this_cpu_read() with raw_cpu_read() in
iommu_range_alloc(). Otherwise we get a warning about using
__this_cpu_read() in preemptible code:
BUG: using __this_cpu_read() in preemptible
caller is iommu_range_alloc+0xa8/0x3d0
Preemption doesn't need to be disabled since according to the comment
any CPU can safely use any IOMMU pool.
Signed-off-by: Victor Aoqui <victora@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The stop4 idle state on POWER9 is a deep idle state which loses
hypervisor resources, but whose latency is low enough that it can be
exposed via cpuidle.
Until now, the deep idle states which lose hypervisor resources (eg:
winkle) were only exposed via CPU-Hotplug. Hence currently on wakeup
from such states, barring a few SPRs which need to be restored to
their older value, rest of the SPRS are reinitialized to their values
corresponding to that at boot time.
When stop4 is used in the context of cpuidle, we want these additional
SPRs to be restored to their older value, to ensure that the context
on the CPU coming back from idle is same as it was before going idle.
In this patch, we define a SPR save area in PACA (since we have used
up the volatile register space in the stack) and on POWER9, we restore
SPRN_PID, SPRN_LDBAR, SPRN_FSCR, SPRN_HFSCR, SPRN_MMCRA, SPRN_MMCR1,
SPRN_MMCR2 to the values they had before entering stop.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The watchdog soft-NMI exception stack setup loads a stack pointer
twice, which is an obvious error. It ends up using the system reset
interrupt (true-NMI) stack, which is also a bug because the watchdog
could be preempted by a system reset interrupt that overwrites the
NMI stack.
Change the soft-NMI to use the "emergency stack". The current kernel
stack is not used, because of the longer-term goal to prevent
asynchronous stack access using soft-disable.
Fixes: 2104180a53 ("powerpc/64s: implement arch-specific hardlockup watchdog")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The fixes branch is based off a random pre-rc1 commit, because we had
some fixes that needed to go in before rc1 was released.
However we now need to fix some code that went in after that point, but
before rc1, so merge rc1 to get that code into fixes so we can fix it!
In smp_cpus_done() we need to call smp_ops->setup_cpu() for the boot
CPU, which means it has to run *on* the boot CPU.
In the past we ensured it ran on the boot CPU by changing the CPU
affinity mask of current directly. That was removed in commit
6d11b87d55 ("powerpc/smp: Replace open coded task affinity logic"),
and replaced with a work queue call.
Unfortunately using a work queue leads to a lockdep warning, now that
the CPU hotplug lock is a regular semaphore:
======================================================
WARNING: possible circular locking dependency detected
...
kworker/0:1/971 is trying to acquire lock:
(cpu_hotplug_lock.rw_sem){++++++}, at: [<c000000000100974>] apply_workqueue_attrs+0x34/0xa0
but task is already holding lock:
((&wfc.work)){+.+.+.}, at: [<c0000000000fdb2c>] process_one_work+0x25c/0x800
...
CPU0 CPU1
---- ----
lock((&wfc.work));
lock(cpu_hotplug_lock.rw_sem);
lock((&wfc.work));
lock(cpu_hotplug_lock.rw_sem);
Although the deadlock can't happen in practice, because
smp_cpus_done() only runs in early boot before CPU hotplug is allowed,
lockdep can't tell that.
Luckily in commit 8fb12156b8 ("init: Pin init task to the boot CPU,
initially") tglx changed the generic code to pin init to the boot CPU
to begin with. The unpinning of init from the boot CPU happens in
sched_init_smp(), which is called after smp_cpus_done().
So smp_cpus_done() is always called on the boot CPU, which means we
don't need the work queue call at all - and the lockdep warning goes
away.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Currently flush_tmregs_to_thread() does not save the TM SPRs (TFHAR,
TFIAR, TEXASR) to the thread struct, unless the process is currently
inside a suspended transaction.
If the process is core dumping, and the TM SPRs have changed since the
last time the process was context switched, then we will save stale
values of the TM SPRs to the core dump.
Fix it by saving the live register state to the thread struct in that
case.
Fixes: 08e1c01d6a ("powerpc/ptrace: Enable support for TM SPR state")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
struct siginfo is a union and the kernel since 2.4 has been hiding a union
tag in the high 16bits of si_code using the values:
__SI_KILL
__SI_TIMER
__SI_POLL
__SI_FAULT
__SI_CHLD
__SI_RT
__SI_MESGQ
__SI_SYS
While this looks plausible on the surface, in practice this situation has
not worked well.
- Injected positive signals are not copied to user space properly
unless they have these magic high bits set.
- Injected positive signals are not reported properly by signalfd
unless they have these magic high bits set.
- These kernel internal values leaked to userspace via ptrace_peek_siginfo
- It was possible to inject these kernel internal values and cause the
the kernel to misbehave.
- Kernel developers got confused and expected these kernel internal values
in userspace in kernel self tests.
- Kernel developers got confused and set si_code to __SI_FAULT which
is SI_USER in userspace which causes userspace to think an ordinary user
sent the signal and that it was not kernel generated.
- The values make it impossible to reorganize the code to transform
siginfo_copy_to_user into a plain copy_to_user. As si_code must
be massaged before being passed to userspace.
So remove these kernel internal si codes and make the kernel code simpler
and more maintainable.
To replace these kernel internal magic si_codes introduce the helper
function siginfo_layout, that takes a signal number and an si_code and
computes which union member of siginfo is being used. Have
siginfo_layout return an enumeration so that gcc will have enough
information to warn if a switch statement does not handle all of union
members.
A couple of architectures have a messed up ABI that defines signal
specific duplications of SI_USER which causes more special cases in
siginfo_layout than I would like. The good news is only problem
architectures pay the cost.
Update all of the code that used the previous magic __SI_ values to
use the new SIL_ values and to call siginfo_layout to get those
values. Escept where not all of the cases are handled remove the
defaults in the switch statements so that if a new case is missed in
the future the lack will show up at compile time.
Modify the code that copies siginfo si_code to userspace to just copy
the value and not cast si_code to a short first. The high bits are no
longer used to hold a magic union member.
Fixup the siginfo header files to stop including the __SI_ values in
their constants and for the headers that were missing it to properly
update the number of si_codes for each signal type.
The fixes to copy_siginfo_from_user32 implementations has the
interesting property that several of them perviously should never have
worked as the __SI_ values they depended up where kernel internal.
With that dependency gone those implementations should work much
better.
The idea of not passing the __SI_ values out to userspace and then
not reinserting them has been tested with criu and criu worked without
changes.
Ref: 2.4.0-test1
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull powerpc fixes from Michael Ellerman:
"A handful of fixes, mostly for new code:
- some reworking of the new STRICT_KERNEL_RWX support to make sure we
also remove executable permission from __init memory before it's
freed.
- a fix to some recent optimisations to the hypercall entry where we
were clobbering r12, this was breaking nested guests (PR KVM).
- a fix for the recent patch to opal_configure_cores(). This could
break booting on bare metal Power8 boxes if the kernel was built
without CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG.
- .. and finally a workaround for spurious PMU interrupts on Power9
DD2.
Thanks to: Nicholas Piggin, Anton Blanchard, Balbir Singh"
* tag 'powerpc-4.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/mm: Mark __init memory no-execute when STRICT_KERNEL_RWX=y
powerpc/mm/hash: Refactor hash__mark_rodata_ro()
powerpc/mm/radix: Refactor radix__mark_rodata_ro()
powerpc/64s: Fix hypercall entry clobbering r12 input
powerpc/perf: Avoid spurious PMU interrupts after idle
powerpc/powernv: Fix boot on Power8 bare metal due to opal_configure_cores()
A previous optimisation incorrectly assumed the PAPR hcall does
not use r12, and clobbers it upon entry. In fact it is used as
an input. This can result in KVM guests crashing (observed with
PR KVM).
Instead of using r12 to save r13, tihs patch saves r13 in ctr.
This is more costly, but not as slow as using the SPRG.
Fixes: acd7d8cef0 ("powerpc/64s: Optimize hypercall/syscall entry")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 DD2 can see spurious PMU interrupts after state-loss idle in
some conditions.
A solution is to save and reload MMCR0 over state-loss idle.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull powerpc fixes from Michael Ellerman:
"Nothing that really stands out, just a bunch of fixes that have come
in in the last couple of weeks.
None of these are actually fixes for code that is new in 4.13. It's
roughly half older bugs, with fixes going to stable, and half
fixes/updates for Power9.
Thanks to: Aneesh Kumar K.V, Anton Blanchard, Balbir Singh, Benjamin
Herrenschmidt, Madhavan Srinivasan, Michael Neuling, Nicholas Piggin,
Oliver O'Halloran"
* tag 'powerpc-4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64: Fix atomic64_inc_not_zero() to return an int
powerpc: Fix emulation of mfocrf in emulate_step()
powerpc: Fix emulation of mcrf in emulate_step()
powerpc/perf: Add POWER9 alternate PM_RUN_CYC and PM_RUN_INST_CMPL events
powerpc/perf: Fix SDAR_MODE value for continous sampling on Power9
powerpc/asm: Mark cr0 as clobbered in mftb()
powerpc/powernv: Fix local TLB flush for boot and MCE on POWER9
powerpc/mm/radix: Synchronize updates to the process table
powerpc/mm/radix: Properly clear process table entry
powerpc/powernv: Tell OPAL about our MMU mode on POWER9
powerpc/kexec: Fix radix to hash kexec due to IAMR/AMOR
Implement an arch-speicfic watchdog rather than use the perf-based
hardlockup detector.
The new watchdog takes the soft-NMI directly, rather than going through
perf. Perf interrupts are to be made maskable in future, so that would
prevent the perf detector from working in those regions.
Additionally, implement a SMP based detector where all CPUs watch one
another by pinging a shared cpumask. This is because powerpc Book3S
does not have a true periodic local NMI, but some platforms do implement
a true NMI IPI.
If a CPU is stuck with interrupts hard disabled, the soft-NMI watchdog
does not work, but the SMP watchdog will. Even on platforms without a
true NMI IPI to get a good trace from the stuck CPU, other CPUs will
notice the lockup sufficiently to report it and panic.
[npiggin@gmail.com: honor watchdog disable at boot/hotplug]
Link: http://lkml.kernel.org/r/20170621001346.5bb337c9@roar.ozlabs.ibm.com
[npiggin@gmail.com: fix false positive warning at CPU unplug]
Link: http://lkml.kernel.org/r/20170630080740.20766-1-npiggin@gmail.com
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170616065715.18390-6-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Tested-by: Babu Moger <babu.moger@oracle.com> [sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Split SOFTLOCKUP_DETECTOR from LOCKUP_DETECTOR, and split
HARDLOCKUP_DETECTOR_PERF from HARDLOCKUP_DETECTOR.
LOCKUP_DETECTOR implies the general boot, sysctl, and programming
interfaces for the lockup detectors.
An architecture that wants to use a hard lockup detector must define
HAVE_HARDLOCKUP_DETECTOR_PERF or HAVE_HARDLOCKUP_DETECTOR_ARCH.
Alternatively an arch can define HAVE_NMI_WATCHDOG, which provides the
minimum arch_touch_nmi_watchdog, and it otherwise does its own thing and
does not implement the LOCKUP_DETECTOR interfaces.
sparc is unusual in that it has started to implement some of the
interfaces, but not fully yet. It should probably be converted to a full
HAVE_HARDLOCKUP_DETECTOR_ARCH.
[npiggin@gmail.com: fix]
Link: http://lkml.kernel.org/r/20170617223522.66c0ad88@roar.ozlabs.ibm.com
Link: http://lkml.kernel.org/r/20170616065715.18390-4-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Tested-by: Babu Moger <babu.moger@oracle.com> [sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are two cases outside the normal address space management
where a CPU's local TLB is to be flushed:
1. Host boot; in case something has left stale entries in the
TLB (e.g., kexec).
2. Machine check; to clean corrupted TLB entries.
CPU state restore from deep idle states also flushes the TLB.
However this seems to be a side effect of reusing the boot code to set
CPU state, rather than a requirement itself.
The current flushing has a number of problems with ISA v3.0B:
- The current radix mode of the MMU is not taken into account. tlbiel
is undefined if the R field does not match the current radix mode.
- ISA v3.0B hash must flush the partition and process table caches.
- ISA v3.0B radix must flush partition and process scoped translations,
partition and process table caches, and also the page walk cache.
Add POWER9 cases to handle these, with radix vs hash determined by the
host MMU mode.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch fixes a crash seen while doing a kexec from radix mode to
hash mode. Key 0 is special in hash and used in the RPN by default, we
set the key values to 0 today. In radix mode key 0 is used to control
supervisor<->user access. In hash key 0 is used by default, so the
first instruction after the switch causes a crash on kexec.
Commit 3b10d0095a ("powerpc/mm/radix: Prevent kernel execution of
user space") introduced the setting of IAMR and AMOR values to prevent
execution of user mode instructions from supervisor mode. We need to
clean up these SPR's on kexec.
Fixes: 3b10d0095a ("powerpc/mm/radix: Prevent kernel execution of user space")
Cc: stable@vger.kernel.org # v4.10+
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull perf fixes from Thomas Gleixner:
"A couple of fixes for perf and kprobes:
- Add he missing exclude_kernel attribute for the precise_ip level so
!CAP_SYS_ADMIN users get the proper results.
- Warn instead of failing completely when perf has no unwind support
for a particular architectiure built in.
- Ensure that jprobes are at function entry and not at some random
place"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kprobes: Ensure that jprobe probepoints are at function entry
kprobes: Simplify register_jprobes()
kprobes: Rename [arch_]function_offset_within_entry() to [arch_]kprobe_on_func_entry()
perf unwind: Do not fail due to missing unwind support
perf evsel: Set attr.exclude_kernel when probing max attr.precise_ip
