The asm code assumes the FP regs are at the start of fp_state. While
this is true now, it may not always be the case and there is nothing
enforcing it.
This fixes the asm-offsets to point to the actual FP registers inside
the fp_state. Similarly for VMX.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The P9 PVR bits 12-15 don't indicate a revision but instead different
chip configurations. From BookIV we have:
Bits Configuration
0 : Scale out 12 cores
1 : Scale out 24 cores
2 : Scale up 12 cores
3 : Scale up 24 cores
DD1 doesn't use this but DD2 does. Linux will mostly use the "Scale
out 24 core" configuration (ie. SMT4 not SMT8) which results in a PVR
of 0x004e1200. The reported revision in /proc/cpuinfo is hence
reported incorrectly as "18.0".
This patch fixes this to mask off only the relevant bits for the major
revision (ie. bits 8-11) for POWER9.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Larry Finger reported that his Powerbook G4 was no longer booting with v4.12-rc,
userspace was up but giving weird errors such as:
udevd[64]: starting version 175
udevd[64]: Unable to receive ctrl message: Bad address.
modprobe: chdir(4.12-rc1): No such file or directory
He bisected the problem to commit 3448890c32 ("powerpc: get rid of zeroing,
switch to RAW_COPY_USER").
Al identified that the problem is actually a miscompilation by GCC 4.6.3, which
is exposed by the above commit.
Al also pointed out that inlining copy_to/from_user() is probably of little or
no benefit, which is correct. Using Anton's copy_to_user benchmark, with a
pathological single byte copy, we see a small increase in performance
by *removing* inlining:
Before (inlined):
# time ./copy_to_user -w -l 1 -i 10000000 ( x 3 )
real 0m22.063s
real 0m22.059s
real 0m22.076s
After:
# time ./copy_to_user -w -l 1 -i 10000000 ( x 3 )
real 0m21.325s
real 0m21.299s
real 0m21.364s
So as a small performance improvement and to avoid the miscompilation, drop
inlining copy_to/from_user() on 32-bit.
Fixes: 3448890c32 ("powerpc: get rid of zeroing, switch to RAW_COPY_USER")
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- three fixes for kprobes/ftrace/livepatch interactions.
- properly handle data breakpoints when using the Radix MMU.
- fix for perf sampling of registers during call_usermodehelper().
- properly initialise the thread_info on our emergency stacks
- add an explicit flush when doing TLB invalidations for a process
using NPU2.
Thanks to:
Alistair Popple, Naveen N. Rao, Nicholas Piggin, Ravi Bangoria,
Masami Hiramatsu.
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Merge tag 'powerpc-4.12-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Some more powerpc fixes for 4.12. Most of these actually came in last
week but got held up for some more testing.
- three fixes for kprobes/ftrace/livepatch interactions.
- properly handle data breakpoints when using the Radix MMU.
- fix for perf sampling of registers during call_usermodehelper().
- properly initialise the thread_info on our emergency stacks
- add an explicit flush when doing TLB invalidations for a process
using NPU2.
Thanks to: Alistair Popple, Naveen N. Rao, Nicholas Piggin, Ravi
Bangoria, Masami Hiramatsu"
* tag 'powerpc-4.12-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64: Initialise thread_info for emergency stacks
powerpc/powernv/npu-dma: Add explicit flush when sending an ATSD
powerpc/perf: Fix oops when kthread execs user process
powerpc/64s: Handle data breakpoints in Radix mode
powerpc/kprobes: Skip livepatch_handler() for jprobes
powerpc/ftrace: Pass the correct stack pointer for DYNAMIC_FTRACE_WITH_REGS
powerpc/kprobes: Pause function_graph tracing during jprobes handling
Add a trace point for tlbie(l) (Translation Lookaside Buffer Invalidate
Entry (Local)) instructions.
The tlbie instruction has changed over the years, so not all versions
accept the same operands. Use the ISA v3 field operands because they are
the most verbose, we may change them in future.
Example output:
qemu-system-ppc-5371 [016] 1412.369519: tlbie:
tlbie with lpid 0, local 1, rb=67bd8900174c11c1, rs=0, ric=0 prs=0 r=0
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Add some missing trace_tlbie()s, reword change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Calling arch_update_cpu_topology from a CPU hotplug state machine callback
hits a deadlock because the function tries to get a read lock on
cpu_hotplug_lock while the state machine still holds a write lock on it.
Since all callers of arch_update_cpu_topology except rtasd already hold
cpu_hotplug_lock, this patch changes the function to use
stop_machine_cpuslocked and creates a separate function for rtasd which
still tries to obtain the lock.
Michael Bringmann investigated the bug and provided a detailed analysis
of the deadlock on this previous RFC for an alternate solution:
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: John Allen <jallen@linux.vnet.ibm.com>
Cc: Michael Bringmann <mwb@linux.vnet.ibm.com>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1497996510-4032-1-git-send-email-bauerman@linux.vnet.ibm.com
Link: https://patchwork.ozlabs.org/patch/771293/
Emergency stacks have their thread_info mostly uninitialised, which in
particular means garbage preempt_count values.
Emergency stack code runs with interrupts disabled entirely, and is
used very rarely, so this has been unnoticed so far. It was found by a
proposed new powerpc watchdog that takes a soft-NMI directly from the
masked_interrupt handler and using the emergency stack. That crashed
at BUG_ON(in_nmi()) in nmi_enter(). preempt_count()s were found to be
garbage.
To fix this, zero the entire THREAD_SIZE allocation, and initialize
the thread_info.
Cc: stable@vger.kernel.org
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Move it all into setup_64.c, use a function not a macro. Fix
crashes on Cell by setting preempt_count to 0 not HARDIRQ_OFFSET]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
NPU2 requires an extra explicit flush to an active GPU PID when
sending address translation shoot downs (ATSDs) to reliably flush the
GPU TLB. This patch adds just such a flush at the end of each sequence
of ATSDs.
We can safely use PID 0 which is always reserved and active on the
GPU. PID 0 is only used for init_mm which will never be a user mm on
the GPU. To enforce this we add a check in pnv_npu2_init_context()
just in case someone tries to use PID 0 on the GPU.
Signed-off-by: Alistair Popple <alistair@popple.id.au>
[mpe: Use true/false for bool literals]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This converts the powerpc VDSO time update function to use the new
interface introduced in commit 576094b7f0 ("time: Introduce new
GENERIC_TIME_VSYSCALL", 2012-09-11). Where the old interface gave
us the time as of the last update in seconds and whole nanoseconds,
with the new interface we get the nanoseconds part effectively in
a binary fixed-point format with tk->tkr_mono.shift bits to the
right of the binary point.
With the old interface, the fractional nanoseconds got truncated,
meaning that the value returned by the VDSO clock_gettime function
would have about 1ns of jitter in it compared to the value computed
by the generic timekeeping code in the kernel.
The powerpc VDSO time functions (clock_gettime and gettimeofday)
already work in units of 2^-32 seconds, or 0.23283 ns, because that
makes it simple to split the result into seconds and fractional
seconds, and represent the fractional seconds in either microseconds
or nanoseconds. This is good enough accuracy for now, so this patch
avoids changing how the VDSO works or the interface in the VDSO data
page.
This patch converts the powerpc update_vsyscall_old to be called
update_vsyscall and use the new interface. We convert the fractional
second to units of 2^-32 seconds without truncating to whole nanoseconds.
(There is still a conversion to whole nanoseconds for any legacy users
of the vdso_data/systemcfg stamp_xtime field.)
In addition, this improves the accuracy of the computation of tb_to_xs
for those systems with high-frequency timebase clocks (>= 268.5 MHz)
by doing the right shift in two parts, one before the multiplication and
one after, rather than doing the right shift before the multiplication.
(We can't do all of the right shift after the multiplication unless we
use 128-bit arithmetic.)
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that userspace can set the virtual SMT mode by enabling the
KVM_CAP_PPC_SMT capability, it is useful for userspace to be able
to query the set of possible virtual SMT modes. This provides a
new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this
information. The return value is a bitmap of possible modes, with
bit N set if virtual SMT mode 2^N is available. That is, 1 indicates
SMT1 is available, 2 indicates that SMT2 is available, 3 indicates
that both SMT1 and SMT2 are available, and so on.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Enhance KVM to cause a guest exit with KVM_EXIT_NMI
exit reason upon a machine check exception (MCE) in
the guest address space if the KVM_CAP_PPC_FWNMI
capability is enabled (instead of delivering a 0x200
interrupt to guest). This enables QEMU to build error
log and deliver machine check exception to guest via
guest registered machine check handler.
This approach simplifies the delivery of machine
check exception to guest OS compared to the earlier
approach of KVM directly invoking 0x200 guest interrupt
vector.
This design/approach is based on the feedback for the
QEMU patches to handle machine check exception. Details
of earlier approach of handling machine check exception
in QEMU and related discussions can be found at:
https://lists.nongnu.org/archive/html/qemu-devel/2014-11/msg00813.html
Note:
This patch now directly invokes machine_check_print_event_info()
from kvmppc_handle_exit_hv() to print the event to host console
at the time of guest exit before the exception is passed on to the
guest. Hence, the host-side handling which was performed earlier
via machine_check_fwnmi is removed.
The reasons for this approach is (i) it is not possible
to distinguish whether the exception occurred in the
guest or the host from the pt_regs passed on the
machine_check_exception(). Hence machine_check_exception()
calls panic, instead of passing on the exception to
the guest, if the machine check exception is not
recoverable. (ii) the approach introduced in this
patch gives opportunity to the host kernel to perform
actions in virtual mode before passing on the exception
to the guest. This approach does not require complex
tweaks to machine_check_fwnmi and friends.
Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Two entries being added at the same time to the IFLA
policy table, whilst parallel bug fixes to decnet
routing dst handling overlapping with the dst gc removal
in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
Since trace_clock is in a different file and already marked with notrace,
enable tracing in time.c by removing it from the disabled list in Makefile.
Also annotate clocksource read functions and sched_clock with notrace.
Testing: Timer and ftrace selftests run with different trace clocks.
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As for slb_miss_realmode(), rename slb_allocate_realmode() to avoid
confusion over whether it runs in real or virtual mode - it runs in
both.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
slb_miss_realmode() doesn't always runs in real mode, which is what the
name implies. So rename it to avoid confusing people.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
All the callers of slb_miss_realmode currently open code the #ifndef
CONFIG_RELOCATABLE check and the branch via CTR in the RELOCATABLE case.
We have a macro to do this, BRANCH_TO_COMMON(), so use it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
It will be used in arch/powerpc/kvm/book3s_hv.c KVM module.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This introduces a new KVM capability to control how KVM behaves
on machine check exception (MCE) in HV KVM guests.
If this capability has not been enabled, KVM redirects machine check
exceptions to guest's 0x200 vector, if the address in error belongs to
the guest. With this capability enabled, KVM will cause a guest exit
with the exit reason indicating an NMI.
The new capability is required to avoid problems if a new kernel/KVM
is used with an old QEMU, running a guest that doesn't issue
"ibm,nmi-register". As old QEMU does not understand the NMI exit
type, it treats it as a fatal error. However, the guest could have
handled the machine check error if the exception was delivered to
guest's 0x200 interrupt vector instead of NMI exit in case of old
QEMU.
[paulus@ozlabs.org - Reworded the commit message to be clearer,
enable only on HV KVM.]
Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
* fix problems that could cause hangs or crashes in the host on POWER9
* fix problems that could allow guests to potentially affect or disrupt
the execution of the controlling userspace
EX_R3 is used only for a small section of the bad stack handler.
Merge it with EX_DAR.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
EX_LR is used only for a small section of the SLB miss handler.
Merge it with EX_DAR.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rather than open-coding it 4 times.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Move __ASSEMBLY__ guards into head-64.h where they're really needed]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The SLB miss handler uses r3 for the faulting address but r12 is
mostly able to be freed up to save r3 in. It just requires SRR1
be reloaded again on error.
It would be more conventional to use r12 for SRR1 (and use r11 to
save r3), but slb_allocate_realmode clobbers r11 and not r12.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The EXCEPTION_PROLOG_1 used by SLB miss already saves CTR when the
kernel is built with CONFIG_RELOCATABLE. So it does not have to be
saved and reloaded when branching to slb_miss_realmode. It can be
restored from the PACA as usual.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The EX_DAR save area is only used in exceptional cases. With r3 no
longer clobbered by slb_allocate_realmode, saving faulting address to
EX_DAR can be deferred to those cases.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
One fewer registers clobbered by this function means the SLB miss
handler can save one fewer.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Conflicts:
kernel/sched/Makefile
Pick up the waitqueue related renames - it didn't get much feedback,
so it appears to be uncontroversial. Famous last words? ;-)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On a POWER9 system, it is possible for an interrupt to become pending
for a VCPU when that VCPU is about to cede (execute a H_CEDE hypercall)
and has already disabled interrupts, or in the H_CEDE processing up
to the point where the XIVE context is pulled from the hardware. In
such a case, the H_CEDE should not sleep, but should return immediately
to the guest. However, the conditions tested in kvmppc_vcpu_woken()
don't include the condition that a XIVE interrupt is pending, so the
VCPU could sleep until the next decrementer interrupt.
To fix this, we add a new xive_interrupt_pending() helper which looks
in the XIVE context that was pulled from the hardware to see if the
priority of any pending interrupt is higher (numerically lower than)
the CPU priority. If so then kvmppc_vcpu_woken() will return true.
If the XIVE context has never been used, then both the pipr and the
cppr fields will be zero and the test will indicate that no interrupt
is pending.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.
This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.
Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.
One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications. For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).
Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.
Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.
Original-patch-by: Oleg Nesterov <oleg@redhat.com>
Original-patch-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the idle sleep/wake code we know that MSR[EE] is clear, so we can
avoid 2 x mfmsr and 2 x mtmsr by calling the double-underscore
versions of the run latch routines which assume interrupts are already
disabled.
Acked-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In a busy system, idle wakeups can be expected from IPIs and device
interrupts.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Idle code now always runs at the 0xc... effective address whether
in real or virtual mode. This means rfid can be ditched, along
with a lot of SRR manipulations.
In the wakeup path, carry SRR1 around in r12. Use mtmsrd to change
MSR states as required.
This also balances the return prediction for the idle call, by
doing blr rather than rfid to return to the idle caller.
On POWER9, 2-process context switch on different cores, with snooze
disabled, increases performance by 2%.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Incorporate v2 fixes from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Have the system reset idle wakeup handlers branched to in real mode
with the 0xc... kernel address applied. This allows simplifications of
avoiding rfid when switching to virtual mode in the wakeup handler.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The __replay_interrupt() code is branched to with bl, but the caller is
returned to directly with rfid from the interrupt.
Instead, rfid to a stub that returns to the caller with blr, which
should keep the return branch predictor balanced.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
msgsnd doorbell exceptions are cleared when the doorbell interrupt is
taken. However if a doorbell exception causes a system reset interrupt
wake from power saving state, the message is not cleared. Processing
the doorbell from the system reset interrupt requires msgclr to avoid
taking the exception again.
Testing this plus the previous wakup direct patch gives:
original wakeup direct msgclr
Different threads, same core: 315k/s 264k/s 345k/s
Different cores: 235k/s 242k/s 242k/s
Net speedup is +10% for same core, and +3% for different core.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the CPU wakes from low power state, it begins at the system reset
interrupt with the exception that caused the wakeup encoded in SRR1.
Today, powernv idle wakeup ignores the wakeup reason (except a special
case for HMI), and the regular interrupt corresponding to the
exception will fire after the idle wakeup exits.
Change this to replay the interrupt from the idle wakeup before
interrupts are hard-enabled.
Test on POWER8 of context_switch selftests benchmark with polling idle
disabled (e.g., always nap, giving cross-CPU IPIs) gives the following
results:
original wakeup direct
Different threads, same core: 315k/s 264k/s
Different cores: 235k/s 242k/s
There is a slowdown for doorbell IPI (same core) case because system
reset wakeup does not clear the message and the doorbell interrupt
fires again needlessly.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rather than concern ourselves with any soft-mask logic in the CPU
hotplug handler, just hard disable interrupts. This ensures there
are no lazy-irqs pending, which means we can call directly to idle
instruction in order to sleep.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This simplifies the asm and fixes irq-off tracing over sleep
instructions.
Also move powersave_nap check for POWER8 into C code, and move
PSSCR register value calculation for POWER9 into C.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On POWER9, we no longer have the restriction that we had on POWER8
where all threads in a core have to be in the same partition, so
the CPU threads are now independent. However, we still want to be
able to run guests with a virtual SMT topology, if only to allow
migration of guests from POWER8 systems to POWER9.
A guest that has a virtual SMT mode greater than 1 will expect to
be able to use the doorbell facility; it will expect the msgsndp
and msgclrp instructions to work appropriately and to be able to read
sensible values from the TIR (thread identification register) and
DPDES (directed privileged doorbell exception status) special-purpose
registers. However, since each CPU thread is a separate sub-processor
in POWER9, these instructions and registers can only be used within
a single CPU thread.
In order for these instructions to appear to act correctly according
to the guest's virtual SMT mode, we have to trap and emulate them.
We cause them to trap by clearing the HFSCR_MSGP bit in the HFSCR
register. The emulation is triggered by the hypervisor facility
unavailable interrupt that occurs when the guest uses them.
To cause a doorbell interrupt to occur within the guest, we set the
DPDES register to 1. If the guest has interrupts enabled, the CPU
will generate a doorbell interrupt and clear the DPDES register in
hardware. The DPDES hardware register for the guest is saved in the
vcpu->arch.vcore->dpdes field. Since this gets written by the guest
exit code, other VCPUs wishing to cause a doorbell interrupt don't
write that field directly, but instead set a vcpu->arch.doorbell_request
flag. This is consumed and set to 0 by the guest entry code, which
then sets DPDES to 1.
Emulating reads of the DPDES register is somewhat involved, because
it requires reading the doorbell pending interrupt status of all of the
VCPU threads in the virtual core, and if any of those VCPUs are
running, their doorbell status is only up-to-date in the hardware
DPDES registers of the CPUs where they are running. In order to get
a reasonable approximation of the current doorbell status, we send
those CPUs an IPI, causing an exit from the guest which will update
the vcpu->arch.vcore->dpdes field. We then use that value in
constructing the emulated DPDES register value.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This allows userspace to set the desired virtual SMT (simultaneous
multithreading) mode for a VM, that is, the number of VCPUs that
get assigned to each virtual core. Previously, the virtual SMT mode
was fixed to the number of threads per subcore, and if userspace
wanted to have fewer vcpus per vcore, then it would achieve that by
using a sparse CPU numbering. This had the disadvantage that the
vcpu numbers can get quite large, particularly for SMT1 guests on
a POWER8 with 8 threads per core. With this patch, userspace can
set its desired virtual SMT mode and then use contiguous vcpu
numbering.
On POWER8, where the threading mode is "strict", the virtual SMT mode
must be less than or equal to the number of threads per subcore. On
POWER9, which implements a "loose" threading mode, the virtual SMT
mode can be any power of 2 between 1 and 8, even though there is
effectively one thread per subcore, since the threads are independent
and can all be in different partitions.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This adds code to allow us to use a different value for the HFSCR
(Hypervisor Facilities Status and Control Register) when running the
guest from that which applies in the host. The reason for doing this
is to allow us to trap the msgsndp instruction and related operations
in future so that they can be virtualized. We also save the value of
HFSCR when a hypervisor facility unavailable interrupt occurs, because
the high byte of HFSCR indicates which facility the guest attempted to
access.
We save and restore the host value on guest entry/exit because some
bits of it affect host userspace execution.
We only do all this on POWER9, not on POWER8, because we are not
intending to virtualize any of the facilities controlled by HFSCR on
POWER8. In particular, the HFSCR bit that controls execution of
msgsndp and related operations does not exist on POWER8. The HFSCR
doesn't exist at all on POWER7.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
It is possible, through a narrow race condition, for a VCPU to exit
the guest with a H_CEDE hypercall while it has a doorbell interrupt
pending. In this case, the H_CEDE should return immediately, but in
fact it puts the VCPU to sleep until some other interrupt becomes
pending or a prod is received (via another VCPU doing H_PROD).
This fixes it by checking the DPDES (Directed Privileged Doorbell
Exception Status) bit for the thread along with the other interrupt
pending bits.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This allows userspace (e.g. QEMU) to enable large decrementer mode for
the guest when running on a POWER9 host, by setting the LPCR_LD bit in
the guest LPCR value. With this, the guest exit code saves 64 bits of
the guest DEC value on exit. Other places that use the guest DEC
value check the LPCR_LD bit in the guest LPCR value, and if it is set,
omit the 32-bit sign extension that would otherwise be done.
This doesn't change the DEC emulation used by PR KVM because PR KVM
is not supported on POWER9 yet.
This is partly based on an earlier patch by Oliver O'Halloran.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Three small fixes for recently merged code:
- remove a spurious WARN_ON when a PCI device has no of_node, it's allowed in
some circumstances for there to be no of_node.
- fix the offset for store EOI MMIOs in the XIVE interrupt controller.
- fix non-const WARN_ONs which were becoming BUGs due to them losing
BUGFLAG_WARNING in a recent cleanup patch.
Thanks to:
Alexey Kardashevskiy, Alistair Popple, Benjamin Herrenschmidt.
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Merge tag 'powerpc-4.12-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Three small fixes for recently merged code:
- remove a spurious WARN_ON when a PCI device has no of_node, it's
allowed in some circumstances for there to be no of_node.
- fix the offset for store EOI MMIOs in the XIVE interrupt
controller.
- fix non-const WARN_ONs which were becoming BUGs due to them losing
BUGFLAG_WARNING in a recent cleanup patch.
Thanks to: Alexey Kardashevskiy, Alistair Popple, Benjamin
Herrenschmidt"
* tag 'powerpc-4.12-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/debug: Add missing warn flag to WARN_ON's non-builtin path
powerpc/xive: Fix offset for store EOI MMIOs
powerpc/npu-dma: Remove spurious WARN_ON when a PCI device has no of_node
When a kthread calls call_usermodehelper() the steps are:
1. allocate current->mm
2. load_elf_binary()
3. populate current->thread.regs
While doing this, interrupts are not disabled. If there is a perf
interrupt in the middle of this process (i.e. step 1 has completed
but not yet reached to step 3) and if perf tries to read userspace
regs, kernel oops with following log:
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc0000000000da0fc
...
Call Trace:
perf_output_sample_regs+0x6c/0xd0
perf_output_sample+0x4e4/0x830
perf_event_output_forward+0x64/0x90
__perf_event_overflow+0x8c/0x1e0
record_and_restart+0x220/0x5c0
perf_event_interrupt+0x2d8/0x4d0
performance_monitor_exception+0x54/0x70
performance_monitor_common+0x158/0x160
--- interrupt: f01 at avtab_search_node+0x150/0x1a0
LR = avtab_search_node+0x100/0x1a0
...
load_elf_binary+0x6e8/0x15a0
search_binary_handler+0xe8/0x290
do_execveat_common.isra.14+0x5f4/0x840
call_usermodehelper_exec_async+0x170/0x210
ret_from_kernel_thread+0x5c/0x7c
Fix it by setting abi to PERF_SAMPLE_REGS_ABI_NONE when userspace
pt_regs are not set.
Fixes: ed4a4ef85c ("powerpc/perf: Add support for sampling interrupt register state")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On Power9, trying to use data breakpoints throws the splat shown
below. This is because the check for a data breakpoint in DSISR is in
do_hash_page(), which is not called when in Radix mode.
Unable to handle kernel paging request for data at address 0xc000000000e19218
Faulting instruction address: 0xc0000000001155e8
cpu 0x0: Vector: 300 (Data Access) at [c0000000ef1e7b20]
pc: c0000000001155e8: find_pid_ns+0x48/0xe0
lr: c000000000116ac4: find_task_by_vpid+0x44/0x90
sp: c0000000ef1e7da0
msr: 9000000000009033
dar: c000000000e19218
dsisr: 400000
Move the check to handle_page_fault() so as to catch data breakpoints
in both Hash and Radix MMU modes.
We have to change the check in do_hash_page() against 0xa410 to use
0xa450, so as to include the value of (DSISR_DABRMATCH << 16).
There are two sites that call handle_page_fault() when in Radix, both
already pass DSISR in r4.
Fixes: caca285e5a ("powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code")
Cc: stable@vger.kernel.org # v4.7+
Reported-by: Shriya R. Kulkarni <shriykul@in.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Fix the fall-through case on hash, we need to reload DSISR]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
ftrace_caller() depends on a modified regs->nip to detect if a certain
function has been livepatched. However, with KPROBES_ON_FTRACE, it is
possible for regs->nip to have been modified by the kprobes pre_handler
(jprobes, for instance). In this case, we do not want to invoke the
livepatch_handler so as not to consume the livepatch stack.
To distinguish between the two (kprobes and livepatch), we check if
there is an active kprobe on the current function. If there is, then we
know for sure that it must have modified the NIP as we don't support
livepatching a kprobe'd function. In this case, we simply skip the
livepatch_handler and branch to the new NIP. Otherwise, the
livepatch_handler is invoked.
Fixes: ead514d5fb ("powerpc/kprobes: Add support for KPROBES_ON_FTRACE")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
For DYNAMIC_FTRACE_WITH_REGS, we should be passing-in the original set
of registers in pt_regs, to capture the state _before_ ftrace_caller.
However, we are instead passing the stack pointer *after* allocating a
stack frame in ftrace_caller. Fix this by saving the proper value of r1
in pt_regs. Also, use SAVE_10GPRS() to simplify the code.
Fixes: 153086644f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This fixes a crash when function_graph and jprobes are used together.
This is essentially commit 237d28db03 ("ftrace/jprobes/x86: Fix
conflict between jprobes and function graph tracing"), but for powerpc.
Jprobes breaks function_graph tracing since the jprobe hook needs to use
jprobe_return(), which never returns back to the hook, but instead to
the original jprobe'd function. The solution is to momentarily pause
function_graph tracing before invoking the jprobe hook and re-enable it
when returning back to the original jprobe'd function.
Fixes: 6794c78243 ("powerpc64: port of the function graph tracer")
Cc: stable@vger.kernel.org # v2.6.30+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When trapped on WARN_ON(), report_bug() is expected to return
BUG_TRAP_TYPE_WARN so the caller will increment NIP by 4 and continue.
The __builtin_constant_p() path of the PPC's WARN_ON()
calls (indirectly) __WARN_FLAGS() which has BUGFLAG_WARNING set,
however the other branch does not which makes report_bug() report a
bug rather than a warning.
Fixes: f26dee1510 ("debug: Avoid setting BUGFLAG_WARNING twice")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 DD1 has an erratum where writing to the TBU40 register, which
is used to apply an offset to the timebase, can cause the timebase to
lose counts. This results in the timebase on some CPUs getting out of
sync with other CPUs, which then results in misbehaviour of the
timekeeping code.
To work around the problem, we make KVM ignore the timebase offset for
all guests on POWER9 DD1 machines. This means that live migration
cannot be supported on POWER9 DD1 machines.
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
At present, HV KVM on POWER8 and POWER9 machines loses any instruction
or data breakpoint set in the host whenever a guest is run.
Instruction breakpoints are currently only used by xmon, but ptrace
and the perf_event subsystem can set data breakpoints as well as xmon.
To fix this, we save the host values of the debug registers (CIABR,
DAWR and DAWRX) before entering the guest and restore them on exit.
To provide space to save them in the stack frame, we expand the stack
frame allocated by kvmppc_hv_entry() from 112 to 144 bytes.
Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Architecturally we should apply a 0x400 offset for these. Not doing
it will break future HW implementations.
The offset of 0 is supposed to remain for "triggers" though not all
sources support both trigger and store EOI, and in P9 specifically,
some sources will treat 0 as a store EOI. But future chips will not.
So this makes us use the properly architected offset which should work
always.
Fixes: 243e25112d ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The ISA v3.0B copy-paste facility only requires cpabort when switching
to a process that has foreign real addresses mapped (direct access to
accelerators), to clear a potential copy buffer filled by a previous
thread. There is no accelerator driver implemented yet, so cpabort can
be removed. It can be be re-added when a driver is implemented.
POWER9 DD1 requires the copy buffer to always be cleared on context
switch, but if accelerators are not in use, then an unpaired copy from
a dummy region is sufficient to clear data out of the copy buffer.
This increases context switch performance by about 5% on POWER9.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The sync (aka. hwsync, aka. heavyweight sync) in the context switch
code to prevent MMIO access being reordered from the point of view of
a single process if it gets migrated to a different CPU is not
required because there is an hwsync performed earlier in the context
switch path.
Comment this so it's clear enough if anything changes on the scheduler
or the powerpc sides. Remove the hwsync from _switch.
This improves context switch performance by 2-3% on POWER8.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is no need to explicitly break the reservation in _switch,
because we are guaranteed that the context switch path will include a
larx/stcx.
Comment the guarantee and remove the reservation clear from _switch.
This is worth 1-2% in context switch performance.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 4387e9ff25 ("[POWERPC] Fix PMU + soft interrupt disable bug")
hard disabled interrupts over the low level context switch, because
the SLB management can't cope with a PMU interrupt accesing the stack
in that window.
Radix based kernel mapping does not use the SLB so it does not require
interrupts hard disabled here.
This is worth 1-2% in context switch performance on POWER9.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The syscall exit code that branches to restore_math is quite heavy on
Book3S, consisting of 2 mtmsr instructions. Threads that don't use both
FP and vector can get caught here if the kernel ever uses FP or vector.
Lazy-FP/vec context switching also trips this case.
So check for lazy FP and vector before switching RI for restore_math.
Move most of this case out of line.
For threads that do want to restore math registers, the MSR switches are
still suboptimal. Future direction may be to use a soft-RI bit to avoid
MSR switches in kernel (similar to soft-EE), but for now at least the
no-restore
POWER9 context switch rate increases by about 5% due to sched_yield(2)
return performance. I haven't constructed a test to measure the syscall
cost.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
After bc3551257a ("powerpc/64: Allow for relocation-on interrupts from
guest to host"), a getppid() system call goes from 307 cycles to 358
cycles (+17%) on POWER8. This is due significantly to the scratch SPR
used by the hypercall check.
It turns out there are a some volatile registers common to both system
call and hypercall (in particular, r12, cr0, ctr), which can be used to
avoid the SPR and some other overheads. This brings getppid to 320 cycles
(+4%).
Testing hcall entry performance by running "sc 1" in guest userspace
before this patch is 854 cycles, afterwards is 826. Also a small win
there.
POWER9 syscall is improved by about the same amount, hcall not tested.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we map the whole linear mapping with PAGE_KERNEL_X. Instead we
should check if the page overlaps the kernel text and only then add
PAGE_KERNEL_X.
Note that we still use 1G pages if they're available, so this will
typically still result in a 1G executable page at KERNELBASE. So this fix is
primarily useful for catching stray branches to high linear mapping addresses.
Without this patch, we can execute at 1G in xmon using:
0:mon> m c000000040000000
c000000040000000 00 l
c000000040000000 00000000 01006038
c000000040000004 00000000 2000804e
c000000040000008 00000000 x
0:mon> di c000000040000000
c000000040000000 38600001 li r3,1
c000000040000004 4e800020 blr
0:mon> p c000000040000000
return value is 0x1
After we get a 400 as expected:
0:mon> p c000000040000000
*** 400 exception occurred
Fixes: 2bfd65e45e ("powerpc/mm/radix: Add radix callbacks for early init routines")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
If userspace attempts to call the KVM_RUN ioctl when it has hardware
transactional memory (HTM) enabled, the values that it has put in the
HTM-related SPRs TFHAR, TFIAR and TEXASR will get overwritten by
guest values. To fix this, we detect this condition and save those
SPR values in the thread struct, and disable HTM for the task. If
userspace goes to access those SPRs or the HTM facility in future,
a TM-unavailable interrupt will occur and the handler will reload
those SPRs and re-enable HTM.
If userspace has started a transaction and suspended it, we would
currently lose the transactional state in the guest entry path and
would almost certainly get a "TM Bad Thing" interrupt, which would
cause the host to crash. To avoid this, we detect this case and
return from the KVM_RUN ioctl with an EINVAL error, with the KVM
exit reason set to KVM_EXIT_FAIL_ENTRY.
Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This restores several special-purpose registers (SPRs) to sane values
on guest exit that were missed before.
TAR and VRSAVE are readable and writable by userspace, and we need to
save and restore them to prevent the guest from potentially affecting
userspace execution (not that TAR or VRSAVE are used by any known
program that run uses the KVM_RUN ioctl). We save/restore these
in kvmppc_vcpu_run_hv() rather than on every guest entry/exit.
FSCR affects userspace execution in that it can prohibit access to
certain facilities by userspace. We restore it to the normal value
for the task on exit from the KVM_RUN ioctl.
IAMR is normally 0, and is restored to 0 on guest exit. However,
with a radix host on POWER9, it is set to a value that prevents the
kernel from executing user-accessible memory. On POWER9, we save
IAMR on guest entry and restore it on guest exit to the saved value
rather than 0. On POWER8 we continue to set it to 0 on guest exit.
PSPB is normally 0. We restore it to 0 on guest exit to prevent
userspace taking advantage of the guest having set it non-zero
(which would allow userspace to set its SMT priority to high).
UAMOR is normally 0. We restore it to 0 on guest exit to prevent
the AMR from being used as a covert channel between userspace
processes, since the AMR is not context-switched at present.
Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Commit 4c3b89effc ("powerpc/powernv: Add sanity checks to
pnv_pci_get_{gpu|npu}_dev") introduced explicit warnings in
pnv_pci_get_npu_dev() when a PCIe device has no associated device-tree
node. However not all PCIe devices have an of_node and
pnv_pci_get_npu_dev() gets indirectly called at least once for every
PCIe device in the system. This results in spurious WARN_ON()'s so
remove it.
The same situation should not exist for pnv_pci_get_gpu_dev() as any
NPU based PCIe device requires a device-tree node.
Fixes: 4c3b89effc ("powerpc/powernv: Add sanity checks to pnv_pci_get_{gpu|npu}_dev")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The IBM vNIC protocol provides support for the user to initiate
a failover from the client LPAR in case the current backing infrastructure
is deemed inadequate or in an error state.
Support for two H_VIOCTL sub-commands for vNIC devices are required
to implement this function. These commands are H_GET_SESSION_TOKEN
and H_SESSION_ERR_DETECTED.
"[H_GET_SESSION_TOKEN] is used to obtain a session token from a VNIC client
adapter. This token is opaque to the caller and is intended to be used in
tandem with the SESSION_ERROR_DETECTED vioctl subfunction."
"[H_SESSION_ERR_DETECTED] is used to report that the currently active
backing device for a VNIC client adapter is behaving poorly, and that
the hypervisor should attempt to fail over to a different backing device,
if one is available."
To provide tools access to this functionality the vNIC driver creates a
sysfs file that, when written to, will send a request to pHyp to failover
to a different backing device.
Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch provides all required callbacks required by the generic
get_user_pages_fast() code and switches x86 over - and removes
the platform specific implementation.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170606113133.22974-2-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This adds code to save the values of three SPRs (special-purpose
registers) used by userspace to control event-based branches (EBBs),
which are essentially interrupts that get delivered directly to
userspace. These registers are loaded up with guest values when
entering the guest, and their values are saved when exiting the
guest, but we were not saving the host values and restoring them
before going back to userspace.
On POWER8 this would only affect userspace programs which explicitly
request the use of EBBs and also use the KVM_RUN ioctl, since the
only source of EBBs on POWER8 is the PMU, and there is an explicit
enable bit in the PMU registers (and those PMU registers do get
properly context-switched between host and guest). On POWER9 there
is provision for externally-generated EBBs, and these are not subject
to the control in the PMU registers.
Since these registers only affect userspace, we can save them when
we first come in from userspace and restore them before returning to
userspace, rather than saving/restoring the host values on every
guest entry/exit. Similarly, we don't need to worry about their
values on offline secondary threads since they execute in the context
of the idle task, which never executes in userspace.
Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The dev_attrs field has long been "depreciated" and is finally being
removed, so move the driver to use the "correct" dev_groups field
instead for struct bus_type.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: <linuxppc-dev@lists.ozlabs.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dev_attrs field has long been "depreciated" and is finally being
removed, so move the driver to use the "correct" dev_groups field
instead for struct bus_type.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: <linuxppc-dev@lists.ozlabs.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull key subsystem fixes from James Morris:
"Here are a bunch of fixes for Linux keyrings, including:
- Fix up the refcount handling now that key structs use the
refcount_t type and the refcount_t ops don't allow a 0->1
transition.
- Fix a potential NULL deref after error in x509_cert_parse().
- Don't put data for the crypto algorithms to use on the stack.
- Fix the handling of a null payload being passed to add_key().
- Fix incorrect cleanup an uninitialised key_preparsed_payload in
key_update().
- Explicit sanitisation of potentially secure data before freeing.
- Fixes for the Diffie-Helman code"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
KEYS: fix refcount_inc() on zero
KEYS: Convert KEYCTL_DH_COMPUTE to use the crypto KPP API
crypto : asymmetric_keys : verify_pefile:zero memory content before freeing
KEYS: DH: add __user annotations to keyctl_kdf_params
KEYS: DH: ensure the KDF counter is properly aligned
KEYS: DH: don't feed uninitialized "otherinfo" into KDF
KEYS: DH: forbid using digest_null as the KDF hash
KEYS: sanitize key structs before freeing
KEYS: trusted: sanitize all key material
KEYS: encrypted: sanitize all key material
KEYS: user_defined: sanitize key payloads
KEYS: sanitize add_key() and keyctl() key payloads
KEYS: fix freeing uninitialized memory in key_update()
KEYS: fix dereferencing NULL payload with nonzero length
KEYS: encrypted: use constant-time HMAC comparison
KEYS: encrypted: fix race causing incorrect HMAC calculations
KEYS: encrypted: fix buffer overread in valid_master_desc()
KEYS: encrypted: avoid encrypting/decrypting stack buffers
KEYS: put keyring if install_session_keyring_to_cred() fails
KEYS: Delete an error message for a failed memory allocation in get_derived_key()
...
When opening the slave end of a PTY, it is not possible for userspace to
safely ensure that /dev/pts/$num is actually a slave (in cases where the
mount namespace in which devpts was mounted is controlled by an
untrusted process). In addition, there are several unresolvable
race conditions if userspace were to attempt to detect attacks through
stat(2) and other similar methods [in addition it is not clear how
userspace could detect attacks involving FUSE].
Resolve this by providing an interface for userpace to safely open the
"peer" end of a PTY file descriptor by using the dentry cached by
devpts. Since it is not possible to have an open master PTY without
having its slave exposed in /dev/pts this interface is safe. This
interface currently does not provide a way to get the master pty (since
it is not clear whether such an interface is safe or even useful).
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Valentin Rothberg <vrothberg@suse.com>
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dev_attrs field has long been "depreciated" and is finally being
removed, so move the driver to use the "correct" dev_groups field
instead for struct bus_type.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dev_attrs field has long been "depreciated" and is finally being
removed, so move the driver to use the "correct" dev_groups field
instead for struct bus_type.
Seems-ok: Geoff Levand <geoff@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for
several 64-bit architectures : mips, parisc, tile.
At the moment and for those architectures, calling in 32-bit userspace the
keyctl syscall would return an ENOSYS error.
This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to
make sure the compatibility wrapper is registered by default for any 64-bit
architecture as long as it is configured with CONFIG_COMPAT.
[DH: Modified to remove arm64 compat enablement also as requested by Eric
Biggers]
Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
cc: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
The PPC_DT_CPU_FTRs is a bit misplaced in menuconfig, it shows up with
other general kernel options. It's really more at home in the "Platform
Support" section, so move it there.
Also enable it by default, for Book3s 64. It does mostly nothing unless
the device tree properties are found, and we will want it enabled
eventually in distro kernels, so turn it on to start getting more
testing.
Fixes: 5a61ef74f2 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Supporting 512TB requires us to do a order 3 allocation for level 1 page
table (pgd). This results in page allocation failures with certain workloads.
For now limit 4k linux page size config to 64TB.
Fixes: f6eedbba7a ("powerpc/mm/hash: Increase VA range to 128TB")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There was only 2 remaining users of CLASS_ATTR() so let's finally get
rid of them and force everyone to use the correct RW/RO/WO versions
instead.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add jited_len to struct bpf_prog. It will be
useful for the struct bpf_prog_info which will
be added in the later patch.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 8d911904f3 ('powerpc/perf: Add restrictions to PMC5 in power9 DD1')
was added to restrict the use of PMC5 in Power9 DD1. Intention was to disable
the use of PMC5 using raw event code. But instead of updating the
power9_isa207_pmu structure (used on DD1), the commit incorrectly updated the
power9_pmu structure. Fix it.
Fixes: 8d911904f3 ("powerpc/perf: Add restrictions to PMC5 in power9 DD1")
Reported-by: Shriya <shriyak@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Tested-by: Shriya <shriyak@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In commit 8c27226119 ("powerpc/numa: Enable USE_PERCPU_NUMA_NODE_ID"), we
switched to the generic implementation of cpu_to_node(), which uses a percpu
variable to hold the NUMA node for each CPU.
Unfortunately we neglected to notice that we use cpu_to_node() in the allocation
of our percpu areas, leading to a chicken and egg problem. In practice what
happens is when we are setting up the percpu areas, cpu_to_node() reports that
all CPUs are on node 0, so we allocate all percpu areas on node 0.
This is visible in the dmesg output, as all pcpu allocs being in group 0:
pcpu-alloc: [0] 00 01 02 03 [0] 04 05 06 07
pcpu-alloc: [0] 08 09 10 11 [0] 12 13 14 15
pcpu-alloc: [0] 16 17 18 19 [0] 20 21 22 23
pcpu-alloc: [0] 24 25 26 27 [0] 28 29 30 31
pcpu-alloc: [0] 32 33 34 35 [0] 36 37 38 39
pcpu-alloc: [0] 40 41 42 43 [0] 44 45 46 47
To fix it we need an early_cpu_to_node() which can run prior to percpu being
setup. We already have the numa_cpu_lookup_table we can use, so just plumb it
in. With the patch dmesg output shows two groups, 0 and 1:
pcpu-alloc: [0] 00 01 02 03 [0] 04 05 06 07
pcpu-alloc: [0] 08 09 10 11 [0] 12 13 14 15
pcpu-alloc: [0] 16 17 18 19 [0] 20 21 22 23
pcpu-alloc: [1] 24 25 26 27 [1] 28 29 30 31
pcpu-alloc: [1] 32 33 34 35 [1] 36 37 38 39
pcpu-alloc: [1] 40 41 42 43 [1] 44 45 46 47
We can also check the data_offset in the paca of various CPUs, with the fix we
see:
CPU 0: data_offset = 0x0ffe8b0000
CPU 24: data_offset = 0x1ffe5b0000
And we can see from dmesg that CPU 24 has an allocation on node 1:
node 0: [mem 0x0000000000000000-0x0000000fffffffff]
node 1: [mem 0x0000001000000000-0x0000001fffffffff]
Cc: stable@vger.kernel.org # v3.16+
Fixes: 8c27226119 ("powerpc/numa: Enable USE_PERCPU_NUMA_NODE_ID")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The i-side 0111b machine check, which is "Instruction Fetch to foreign
address space", was missed by 7b9f71f974 ("powerpc/64s: POWER9 machine
check handler").
The POWER9 processor core considers host real addresses with a
nonzero value in RA(8:12) as foreign address space, accessible only
by the copy and paste instructions. The copy and paste instruction
pair can be used to invoke the Nest accelerators via the Virtual
Accelerator Switchboard (VAS).
It is an error for any regular load/store or ifetch to go to a foreign
addresses. When relocation is on, this causes an MMU exception. When
relocation is off, a machine check exception. It is possible to trigger
this machine check by branching to a foreign address with MSR[IR]=0.
Fixes: 7b9f71f974 ("powerpc/64s: POWER9 machine check handler")
Reported-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently tsk->thread.load_tm is not initialized in the task creation
and can contain garbage on a new task.
This is an undesired behaviour, since it affects the timing to enable
and disable the transactional memory laziness (disabling and enabling
the MSR TM bit, which affects TM reclaim and recheckpoint in the
scheduling process).
Fixes: 5d176f751e ("powerpc: tm: Enable transactional memory (TM) lazily for userspace")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These two functions implement the same semantics, so unify their naming so we
can share code that calls them. The longer name is more descriptive so use it.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add support in pte_alloc_one() and pgd_alloc() by
passing __GFP_ACCOUNT in the flags
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Introduce a helper pgtable_gfp_flags() which
just returns the current gfp flags and adds
__GFP_ACCOUNT to account for page table allocation.
The generic helper is added to include/asm/pgalloc.h
and has two variants - WARNING ugly bits ahead
1. If the header is included from a module, no check
for mm == &init_mm is done, since init_mm is not
exported
2. For kernel includes, the check is done and required
see (3e79ec7 arch: x86: charge page tables to kmemcg)
The fundamental assumption is that no module should be
doing pgd/pud/pmd and pte alloc's on behalf of init_mm
directly.
NOTE: This adds an overhead to pmd/pud/pgd allocations
similar to x86. The other alternative was to implement
pmd_alloc_kernel/pud_alloc_kernel and pgd_alloc_kernel
with their offset variants.
For 4k page size, pte_alloc_one no longer calls
pte_alloc_one_kernel.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently in hpte_need_flush() if there is no batch pending we always do a
global TLB flush, which is inefficient if the mm has never run on another
thread.
Instead do the same check that __flush_tlb_pending() does and check if a local
flush is sufficient when batch->active is false. Instead of open-coding it we
use mm_is_thread_local().
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Don't use a local, just inline mm_is_thread_local()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Collation of some spelling fixes from Colin.
Attemping -> Attempting
intialized -> initialized
missmanaged -> mismanaged
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently tsk->thread->load_vec and load_fp are not initialized during
task creation, which can lead to garbage values in these variables (non-zero
values).
These variables will be checked later in restore_math() to validate if the
FP and vector registers are being utilized. Since these values might be
non-zero, the restore_math() will continue to save the FP and vectors even if
they were never utilized by the userspace application. load_fp and load_vec
counters will then overflow (they wrap at 255) and the FP and Altivec will be
finally disabled, but before that condition is reached (counter overflow)
several context switches will have restored FP and vector registers without
need, causing a performance degradation.
Fixes: 70fe3d980f ("powerpc: Restore FPU/VEC/VSX if previously used")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Gustavo Romero <gusbromero@gmail.com>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
A first step in vcpu->requests encapsulation. Additionally, we now
use READ_ONCE() when accessing vcpu->requests, which ensures we
always load vcpu->requests when it's accessed. This is important as
other threads can change it any time. Also, READ_ONCE() documents
that vcpu->requests is used with other threads, likely requiring
memory barriers, which it does.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[ Documented the new use of READ_ONCE() and converted another check
in arch/mips/kvm/vz.c ]
Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Marc Zyngier suggested that we define the arch specific VCPU request
base, rather than requiring each arch to remember to start from 8.
That suggestion, along with Radim Krcmar's recent VCPU request flag
addition, snowballed into defining something of an arch VCPU request
defining API.
No functional change.
(Looks like x86 is running out of arch VCPU request bits. Maybe
someday we'll need to extend to 64.)
Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
The xor_vmx.c file is used for the RAID5 xor operations. In these functions
altivec is enabled to run the operation and then disabled.
The code uses enable_kernel_altivec() around the core of the algorithm, however
the whole file is built with -maltivec, so the compiler is within its rights to
generate altivec code anywhere. This has been seen at least once in the wild:
0:mon> di $xor_altivec_2
c0000000000b97d0 3c4c01d9 addis r2,r12,473
c0000000000b97d4 3842db30 addi r2,r2,-9424
c0000000000b97d8 7c0802a6 mflr r0
c0000000000b97dc f8010010 std r0,16(r1)
c0000000000b97e0 60000000 nop
c0000000000b97e4 7c0802a6 mflr r0
c0000000000b97e8 faa1ffa8 std r21,-88(r1)
...
c0000000000b981c f821ff41 stdu r1,-192(r1)
c0000000000b9820 7f8101ce stvx v28,r1,r0 <-- POP
c0000000000b9824 38000030 li r0,48
c0000000000b9828 7fa101ce stvx v29,r1,r0
...
c0000000000b984c 4bf6a06d bl c0000000000238b8 # enable_kernel_altivec
This patch splits the non-altivec code into xor_vmx_glue.c which calls the
altivec functions in xor_vmx.c. By compiling xor_vmx_glue.c without
-maltivec we can guarantee that altivec instruction will not be executed
outside of the enable/disable block.
Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com>
[mpe: Rework change log and include disassembly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
By default, 5% of system RAM is reserved for preserving boot memory.
Alternatively, a user can specify the amount of memory to reserve.
See Documentation/powerpc/firmware-assisted-dump.txt for details. In
addition to the memory reserved for preserving boot memory, some more
memory is reserved, to save HPTE region, CPU state data and ELF core
headers.
Memory Reservation during first kernel looks like below:
Low memory Top of memory
0 boot memory size |
| | |<--Reserved dump area -->|
V V | Permanent Reservation V
+-----------+----------/ /----------+---+----+-----------+----+
| | |CPU|HPTE| DUMP |ELF |
+-----------+----------/ /----------+---+----+-----------+----+
| ^
| |
\ /
-------------------------------------------
Boot memory content gets transferred to
reserved area by firmware at the time of
crash
This implicitly means that the sum of the sizes of boot memory, CPU
state data, HPTE region, DUMP preserving area and ELF core headers
can't be greater than the total memory size. But currently, a user is
allowed to specify any value as boot memory size. So, the above rule
is violated when a boot memory size around 50% of the total available
memory is specified. As the kernel is not handling this currently, it
may lead to undefined behavior. Fix it by setting an upper limit for
boot memory size to 25% of the total available memory. Also, instead
of using memblock_end_of_DRAM(), which doesn't take the holes, if any,
in the memory layout into account, use memblock_phys_mem_size() to
calculate the percentage of total available memory.
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With commit f6e6bedb77 ("powerpc/fadump: Reserve memory at an offset
closer to bottom of RAM"), memory for fadump is no longer reserved at
the top of RAM. But there are still a few places which say so. Change
them appropriately.
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With commit 11550dc0a0 ("powerpc/fadump: reuse crashkernel parameter
for fadump memory reservation"), 'fadump_reserve_mem=' parameter is
deprecated in favor of 'crashkernel=' parameter. Add a warning if
'fadump_reserve_mem=' is still used.
Fixes: 11550dc0a0 ("powerpc/fadump: reuse crashkernel parameter for fadump memory reservation")
Suggested-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Unsplit long printk strings]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- log an error message when registration fails and no error code listed
in the switch is returned
- translate the hv error code to posix error code and return it from
fw_register
- return the posix error code from fw_register to the process writing
to sysfs
- return EEXIST on re-registration
- return success on deregistration when fadump is not registered
- return ENODEV when no memory is reserved for fadump
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Tested-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Use pr_err() to shrink the error print]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With the ffz() function as defined in arch/powerpc/include/asm/bitops.h
GCC will not optimise the code in case of constant parameter.
This patch replaces ffz() by the generic function.
The generic ffz(x) expects to never be called with ~x == 0
as written in the comment in include/asm-generic/bitops/ffz.h
The only user of ffz() within arch/powerpc/ is
platforms/512x/mpc5121_ads_cpld.c, which checks if x is not 0xff
For non constant calls, the generated code is doing the same:
unsigned long testffz(unsigned long x)
{
return ffz(x);
}
On PPC32, before the patch:
00000018 <testffz>:
18: 7c 63 18 f9 not. r3,r3
1c: 40 82 00 0c bne 28 <testffz+0x10>
20: 38 60 00 20 li r3,32
24: 4e 80 00 20 blr
28: 7d 23 00 d0 neg r9,r3
2c: 7d 23 18 38 and r3,r9,r3
30: 7c 63 00 34 cntlzw r3,r3
34: 20 63 00 1f subfic r3,r3,31
38: 4e 80 00 20 blr
On PPC32, after the patch:
00000018 <testffz>:
18: 39 23 00 01 addi r9,r3,1
1c: 7d 23 18 78 andc r3,r9,r3
20: 7c 63 00 34 cntlzw r3,r3
24: 20 63 00 1f subfic r3,r3,31
28: 4e 80 00 20 blr
On PPC64, before the patch:
0000000000000030 <.testffz>:
30: 7c 60 18 f9 not. r0,r3
34: 38 60 00 40 li r3,64
38: 4d 82 00 20 beqlr
3c: 7c 60 00 d0 neg r3,r0
40: 7c 63 00 38 and r3,r3,r0
44: 7c 63 00 74 cntlzd r3,r3
48: 20 63 00 3f subfic r3,r3,63
4c: 7c 63 07 b4 extsw r3,r3
50: 4e 80 00 20 blr
On PPC64, after the patch:
0000000000000030 <.testffz>:
30: 38 03 00 01 addi r0,r3,1
34: 7c 03 18 78 andc r3,r0,r3
38: 7c 63 00 74 cntlzd r3,r3
3c: 20 63 00 3f subfic r3,r3,63
40: 4e 80 00 20 blr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It often happens to have simultaneous interrupts, for instance
when having double Ethernet attachment. With the current
implementation, we suffer the cost of kernel entry/exit for each
interrupt.
This patch introduces a loop in __do_irq() to handle all interrupts
at once before returning.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
IRQ 0 is a valid HW interrupt. So get_irq() shall return 0 when
there is no irq, instead of returning irq_linear_revmap(... ,0)
Fixes: f2a0bd3753 ("[POWERPC] 8xx: powerpc port of core CPM PIC")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The 8xx has a dedicated exception for breakpoints, that directly
calls do_break()
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The result of (trap == 0x400) is already in is_exec.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Function store_updates_sp() checks whether the faulting
instruction is a store updating r1. Therefore we can limit its calls
to store exceptions.
This patch is an improvement of commit a7a9dcd882 ("powerpc: Avoid
taking a data miss on every userspace instruction miss")
With the same microbenchmark app, run with 500 as argument, on an
MPC885 we get:
Before this patch: 152000 DTLB misses
After this patch: 147000 DTLB misses
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This function has not been used since commit 9494a1e842
("powerpc: use generic fixmap.h)
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The check in hpte_find() should be < and not <= for PAGE_OFFSET
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
asm-generic/socket.h already has an exception for the differences that
powerpc needs, so just include it after defining the differences.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
We are running low on CPU feature bits, so we only want to use them when
it's really necessary.
CPU_FTR_SUBCORE is only used in one place, and only in C, so we don't
need it in order to make asm patching work. It can only be set on
"Power8" CPUs, which in practice means POWER8, POWER8E and POWER8NVL.
There are no plans to implement it on future CPUs, but if there ever
were we could retrofit it then.
Although KVM uses subcores, it never looks at the CPU feature, it either
looks at the ISA level or the threads_per_subcore value.
So drop the CPU feature and do a PVR check instead. Drop the device tree
"subcore" feature as we no longer support doing anything with it, and we
will drop it from skiboot too.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When adding or removing memory, the aa_index (affinity value) for the
memblock must also be converted to match the endianness of the rest
of the 'ibm,dynamic-memory' property. Otherwise, subsequent retrieval
of the attribute will likely lead to non-existent nodes, followed by
using the default node in the code inappropriately.
Fixes: 5f97b2a0d1 ("powerpc/pseries: Implement memory hotplug add in the kernel")
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If a process dumps core while it has SPU contexts active then we have
code to also dump information about the SPU contexts.
Unfortunately it's been broken for 3 1/2 years, and we didn't notice. In
commit 7b1f4020d0 ("spufs: get rid of dump_emit() wrappers") the nread
variable was removed and rc used instead. That means when the loop exits
successfully, rc has the number of bytes read, but it's then used as the
return value for the function, which should return 0 on success.
So fix it by setting rc = 0 before returning in the success case.
Fixes: 7b1f4020d0 ("spufs: get rid of dump_emit() wrappers")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Provide a dt_cpu_ftrs= cmdline option to disable the dt_cpu_ftrs CPU
feature discovery, and fall back to the "cputable" based version.
Also allow control of advertising unknown features to userspace and
with this parameter, and remove the clunky CONFIG option.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add explicit early check of bootargs in dt_cpu_ftrs_init()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
free up BPF_JMP | BPF_CALL | BPF_X opcode to be used by actual
indirect call by register and use kernel internal opcode to
mark call instruction into bpf_tail_call() helper.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add --orphan-handling=warn to final link flags. This ensures we can
handle all sections explicitly. This would have caught subtle breakage
such as 7de3b27bac at build-time.
Also bring existing orphan sections into the fold:
- .text.hot and .text.unlikely are compiler generated sections.
- .sdata2, .dynsbss, .plt are used by PPC32
- We previously did not specify DWARF_DEBUG or STABS_DEBUG
- DWARF_DEBUG did not include all DWARF sections that can be emitted
- A number of sections are unused and can be discarded.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Use a tool to check that the location of "fixed sections" are where
we expected them to be, which catches cases the linker script can't
(stubs being added to start of .text section), and which ends up
being neater.
Sample output:
ERROR: start_text address is c000000000008100, should be c000000000008000
ERROR: see comments in arch/powerpc/tools/head_check.sh
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fold in fix from Nick for 4.6 era toolchains]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Very large kernels may require linker stubs for branches from HEAD
text code. The linker may place these stubs before the HEAD text
sections, which breaks the assumption that HEAD text is located at 0
(or the .text section being located at 0x7000/0x8000 on Book3S
kernels).
Provide an option to create a small section just before the .text
section with an empty 256 - 4 bytes, and adjust the start of the .text
section to match. The linker will tend to put stubs in that section
and not break our relative-to-absolute offset assumptions.
This causes a small waste of space on common kernels, but allows large
kernels to build and boot. For now, it is an EXPERT config option,
defaulting to =n, but a reference is provided for it in the build-time
check for such breakage. This is good enough for allyesconfig and
custom users / hackers.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Direct banches from code below __end_interrupts to code above
__end_interrupts when built with CONFIG_RELOCATABLE are disallowed
because they will break when the kernel is not located at 0.
Sample output:
WARNING: Unrelocated relative branches
c000000000000118 bl-> 0xc000000000038fb8 <pnv_restore_hyp_resource>
c00000000000013c b-> 0xc0000000001068a4 <kvm_start_guest>
c000000000000148 b-> 0xc00000000003919c <pnv_wakeup_loss>
c00000000000014c b-> 0xc00000000003923c <pnv_wakeup_noloss>
c0000000000005a4 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
c000000000001af0 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
c000000000001b24 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
c000000000001b58 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
For final link, the powerpc64 linker generates fpr save/restore
functions on-demand, placing them in the .sfpr section. Starting with
binutils 2.25, these can be provided for non-final links with
--save-restore-funcs. Use that where possible for module links.
This saves about 200 bytes per module (~60kB) on powernv defconfig
build.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is no need to create a new section for these. Consolidate with
32-bit and just use .text.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
crtsaveres.S is empty with 64-bit builds already, so just don't
build and link it to match the vmlinux build.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use CONFIG_PPC64_BOOT_WRAPPER not CONFIG_PPC32 to fix BE build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The 64-bit linker creates save/restore functions on demand with final
links, so vmlinux does not require crtsavres.o.
Make crtsavres.o extra-y on 64-bit (it is still required by modules).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The arch version is identical except for comments and white space.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These are completely obvious as all they do is include the asm-generic
versions.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Prevent a kernel panic caused by unintentionally clearing TCR watchdog
bits. At this point in the kernel boot, the watchdog may have already
been enabled by u-boot. The original code's attempt to write to the TCR
register results in an inadvertent clearing of the watchdog
configuration bits, causing the 476 to reset.
Signed-off-by: Ivan Mikhaylov <ivan@de.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds default FSP2 config for main usage.
Signed-off-by: Ivan Mikhaylov <ivan@de.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add platform code support for FSP2 (476fpe) board.
Signed-off-by: Ivan Mikhaylov <ivan@de.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On Power9 DD1 due to a hardware bug the Power-Saving Level Status
field (PLS) of the PSSCR for a thread waking up from a deep state can
under-report if some other thread in the core is in a shallow stop
state. The scenario in which this can manifest is as follows:
1) All the threads of the core are in deep stop.
2) One of the threads is woken up. The PLS for this thread will
correctly reflect that it is waking up from deep stop.
3) The thread that has woken up now executes a shallow stop.
4) When some other thread in the core is woken, its PLS will reflect
the shallow stop state.
Thus, the subsequent thread for which the PLS is under-reporting the
wakeup state will not restore the hypervisor resources.
Hence, on DD1 systems, use the Requested Level (RL) field as a
workaround to restore the contents of the hypervisor resources on the
wakeup from the stop state.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Some of the SPR values (HID0, MSR, SPRG0) don't change during the run
time of a booted kernel, once they have been initialized.
The contents of these SPRs are lost when the CPUs enter deep stop
states. So instead saving and restoring SPRs from the kernel, use the
stop-api provided by the firmware by which the firmware can restore
the contents of these SPRs to their initialized values after wakeup
from a deep stop state.
Apart from these, program the PSSCR value to that of the deepest stop
state via the stop-api. This will be used to indicate to the
underlying firmware as to what stop state to put the threads that have
been woken up by a special-wakeup.
And while we are at programming SPRs via stop-api, ensure that HID1,
HID4 and HID5 registers which are only available on POWER8 are not
requested to be restored by the firware on POWER9.
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On wakeup from a deep stop state which is supposed to lose the
hypervisor state, we don't restore the LPCR to the old value but set
it to a "sane" value via cur_cpu_spec->cpu_restore().
The problem is that the "sane" value doesn't include UPRT and the HR
bits which are required to run correctly in Radix mode.
Fix this on POWER9 onwards by restoring the LPCR value whatever it was
before executing the stop instruction.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On POWER8, in case of
- nap: both timebase and hypervisor state is retained.
- fast-sleep: timebase is lost. But the hypervisor state is retained.
- winkle: timebase and hypervisor state is lost.
Hence, the current code for handling exit from a idle state assumes
that if the timebase value is retained, then so is the hypervisor
state. Thus, the current code doesn't restore per-core hypervisor
state in such cases.
But that is no longer the case on POWER9 where we do have stop states
in which timebase value is retained, but the hypervisor state is
lost. So we have to ensure that the per-core hypervisor state gets
restored in such cases.
Fix this by ensuring that even in the case when timebase is retained,
we explicitly check if we are waking up from a deep stop that loses
per-core hypervisor state (indicated by cr4 being eq or gt), and if
this is the case, we restore the per-core hypervisor state.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The lower 8 bits of core_idle_state_ptr tracks the number of non-idle
threads in the core. This is supposed to be initialized to bit-map
corresponding to the threads_per_core. However, currently it is
initialized to PNV_CORE_IDLE_THREAD_BITS (0xFF). This is correct for
POWER8 which has 8 threads per core, but not for POWER9 which has 4
threads per core.
As a result, on POWER9, core_idle_state_ptr gets initialized to
0xFF. In case when all the threads of the core are idle, the bits
corresponding tracking the idle-threads are non-zero. As a result, the
idle entry/exit code fails to save/restore per-core hypervisor state
since it assumes that there are threads in the cores which are still
active.
Fix this by correctly initializing the lower bits of the
core_idle_state_ptr on the basis of threads_per_core.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Allow us to enable IRQ_TIME_ACCOUNTING. Even though we currently
use VIRT_CPU_ACCOUNTING_NATIVE, that option is quite heavy
weight and IRQ_TIME_ACCOUNTING might be better in some cases.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the DTS defines two partitions at the same addresses, if you
use one, you will corrupt information on the other one. Fix it by
shifting the second partition.
Signed-off-by: Pavel Machek <pavel@denx.de>
[mpe: Reconstruct change log from email thread]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Experiments with the netperf benchmark indicated that the size selecting
VMX-based copies in __copy_tofrom_user_power7() was suboptimal on POWER8.
Measurements showed that parity was in the neighbourhood of 3328 bytes,
rather than greater than 4096. The change gives a 1.5-2.0% improvement in
performance for 4096-byte buffers, reducing the relative time spent in
__copy_tofrom_user_power7() from approximately 7% to approximately 5% in
the TCP_RR benchmark.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rearrange the code so that mode and badaddr are only defined when
they're used.
Also unsplit the string for easier grepping, and switch from CONFIG_8xx
which is deprecated to CONFIG_PPC_8xx.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fixes: a7cd88da97 ("powerpc/powernv: Move CPU-Offline idle state invocation from smp.c to idle.c")
Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
OPAL_CALL uses SRR[01] with MSR_RI=1, which gets corrupted if there
is an interleaving system reset or machine check interrupt.
Use HSRR[01] instead, which does not require MSR_RI=0.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Neuling