commit c13f20ac48 upstream.
The VSX MSR bit in the user context indicates if the context contains VSX
state. Currently we set this when the process has touched VSX at any stage.
Unfortunately, if the user has not provided enough space to save the VSX state,
we can't save it but we currently still set the MSR VSX bit.
This patch changes this to clear the MSR VSX bit when the user doesn't provide
enough space. This indicates that there is no valid VSX state in the user
context.
This is needed to support get/set/make/swapcontext for applications that use
VSX but only provide a small context. For example, getcontext in glibc
provides a smaller context since the VSX registers don't need to be saved over
the glibc function call. But since the program calling getcontext may have
used VSX, the kernel currently says the VSX state is valid when it's not. If
the returned context is then used in setcontext (ie. a small context without
VSX but with MSR VSX set), the kernel will refuse the context. This situation
has been reported by the glibc community.
Based on patch from Carlos O'Donell.
Tested-by: Haren Myneni <haren@linux.vnet.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5a049f1490 upstream.
Commit fba2369e6c (mm: use vm_unmapped_area() on powerpc architecture)
has a bug in slice_scan_available() where we compare an unsigned long
(high_slices) against a shifted int. As a result, comparisons against
the top 32 bits of high_slices (representing the top 32TB) always
returns 0 and the top of our mmap region is clamped at 32TB
This also breaks mmap randomisation since the randomised address is
always up near the top of the address space and it gets clamped down
to 32TB.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 631ad691b5 upstream.
We need add PE to its own PELTV. Otherwise, the errors originated
from the PE might contribute to other PEs. In the result, we can't
clear up the error successfully even we're checking and clearing
errors during access to PCI config space.
Reported-by: kalshett@in.ibm.com
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2bf75084f6 upstream.
The MPC5200 LPBFIFO driver requires the bestcomm module to be
enabled, otherwise building will fail. Fix it.
Reported-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cfc860253a upstream.
This fixes a typo in the code that saves the guest DSCR (Data Stream
Control Register) into the kvm_vcpu_arch struct on guest exit. The
effect of the typo was that the DSCR value was saved in the wrong place,
so changes to the DSCR by the guest didn't persist across guest exit
and entry, and some host kernel memory got corrupted.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8f21bd0090 upstream.
The csum_partial_copy_generic() function saves the PowerPC non-volatile
r14, r15, and r16 registers for the main checksum-and-copy loop.
Unfortunately, it fails to restore them upon error exit from this loop,
which results in silent corruption of these registers in the presumably
rare event of an access exception within that loop.
This commit therefore restores these register on error exit from the loop.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d1211af304 upstream.
arch/powerpc/kernel/sysfs.c exports PURR with write permission.
This may be valid for kernel in phyp mode. But writing to
the file in guest mode causes crash due to a priviledge violation
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d9813c3681 upstream.
The csum_partial_copy_generic() uses register r7 to adjust the remaining
bytes to process. Unfortunately, r7 also holds a parameter, namely the
address of the flag to set in case of access exceptions while reading
the source buffer. Lacking a quantum implementation of PowerPC, this
commit instead uses register r9 to do the adjusting, leaving r7's
pointer uncorrupted.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e82b89a6f1 upstream.
modalias_show() should return an empty string on error, not -ENODEV.
This causes the following false and annoying error:
> find /sys/devices -name modalias -print0 | xargs -0 cat >/dev/null
cat: /sys/devices/vio/4000/modalias: No such device
cat: /sys/devices/vio/4001/modalias: No such device
cat: /sys/devices/vio/4002/modalias: No such device
cat: /sys/devices/vio/4004/modalias: No such device
cat: /sys/devices/vio/modalias: No such device
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e9bdc3d614 upstream.
When we do a treclaim or trecheckpoint we end up running with userspace
PPR and DSCR values. Currently we don't do anything special to avoid
running with user values which could cause a severe performance
degradation.
This patch moves the PPR and DSCR save and restore around treclaim and
trecheckpoint so that we run with user values for a much shorter period.
More care is taken with the PPR as it's impact is greater than the DSCR.
This is similar to user exceptions, where we run HTM_MEDIUM early to
ensure that we don't run with a userspace PPR values in the kernel.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a53b27b3ab upstream.
Commit 4df4899 "Add power8 EBB support" included a bug in the handling
of the FAB_CRESP_MATCH and FAB_TYPE_MATCH fields.
These values are pulled out of the event code using EVENT_THR_CTL_SHIFT,
however we were then or'ing that value directly into MMCR1.
This meant we were failing to set the FAB fields correctly, and also
potentially corrupting the value for PMC4SEL. Leading to no counts for
the FAB events and incorrect counts for PMC4.
The fix is simply to shift left the FAB value correctly before or'ing it
with MMCR1.
Reported-by: Sooraj Ravindran Nair <soonair3@in.ibm.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1cf389df09 upstream.
Under heavy (DLPAR?) stress, we tripped this panic() in
arch/powerpc/kernel/iommu.c::iommu_init_table():
page = alloc_pages_node(nid, GFP_ATOMIC, get_order(sz));
if (!page)
panic("iommu_init_table: Can't allocate %ld bytes\n", sz);
Before the panic() we got a page allocation failure for an order-2
allocation. There appears to be memory free, but perhaps not in the
ATOMIC context. I looked through all the call-sites of
iommu_init_table() and didn't see any obvious reason to need an ATOMIC
allocation. Most call-sites in fact have an explicit GFP_KERNEL
allocation shortly before the call to iommu_init_table(), indicating we
are not in an atomic context. There is some indirection for some paths,
but I didn't see any locks indicating that GFP_KERNEL is inappropriate.
With this change under the same conditions, we have not been able to
reproduce the panic.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7bfa9ad55d upstream.
Commit 8e44ddc3f3 ("powerpc/kvm/book3s: Add support for H_IPOLL and
H_XIRR_X in XICS emulation") added a call to get_tb() but didn't
include the header that defines it, and on some configs this means
book3s_xics.c fails to compile:
arch/powerpc/kvm/book3s_xics.c: In function ‘kvmppc_xics_hcall’:
arch/powerpc/kvm/book3s_xics.c:812:3: error: implicit declaration of function ‘get_tb’ [-Werror=implicit-function-declaration]
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 363edbe261 upstream.
When adding cpuidle support to pSeries, we introduced two
regressions:
- The new cpuidle backend driver only works under hypervisors
supporting the "SLPLAR" option, which isn't the case of the
old POWER4 hypervisor and the HV "light" used on js2x blades
- The cpuidle driver registers fairly late, meaning that for
a significant portion of the boot process, we end up having
all threads spinning. This slows down the boot process and
increases the overall resource usage if the hypervisor has
shared processors.
This fixes both by implementing a "default" idle that will cede
to the hypervisor when possible, in a very simple way without
all the bells and whisles of cpuidle.
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Acked-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 230aef7a6a upstream.
Normally when we haven't implemented an alignment handler for
a load or store instruction the process will be terminated.
The alignment handler uses the DSISR (or a pseudo one) to locate
the right handler. Unfortunately ldbrx and stdbrx overlap lfs and
stfs so we incorrectly think ldbrx is an lfs and stdbrx is an
stfs.
This bug is particularly nasty - instead of terminating the
process we apply an incorrect fixup and continue on.
With more and more overlapping instructions we should stop
creating a pseudo DSISR and index using the instruction directly,
but for now add a special case to catch ldbrx/stdbrx.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f5f6cbb616 upstream.
/proc/powerpc/lparcfg is an ancient facility (though still actively used)
which allows access to some informations relative to the partition when
running underneath a PAPR compliant hypervisor.
It makes no sense on non-pseries machines. However, currently, not only
can it be created on these if the kernel has pseries support, but accessing
it on such a machine will crash due to trying to do hypervisor calls.
In fact, it should also not do HV calls on older pseries that didn't have
an hypervisor either.
Finally, it has the plumbing to be a module but is a "bool" Kconfig option.
This fixes the whole lot by turning it into a machine_device_initcall
that is only created on pseries, and adding the necessary hypervisor
check before calling the H_GET_EM_PARMS hypercall
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bdbc29c19b upstream.
On 64-bit, __pa(&static_var) gets miscompiled by recent versions of
gcc as something like:
addis 3,2,.LANCHOR1+4611686018427387904@toc@ha
addi 3,3,.LANCHOR1+4611686018427387904@toc@l
This ends up effectively ignoring the offset, since its bottom 32 bits
are zero, and means that the result of __pa() still has 0xC in the top
nibble. This happens with gcc 4.8.1, at least.
To work around this, for 64-bit we make __pa() use an AND operator,
and for symmetry, we make __va() use an OR operator. Using an AND
operator rather than a subtraction ends up with slightly shorter code
since it can be done with a single clrldi instruction, whereas it
takes three instructions to form the constant (-PAGE_OFFSET) and add
it on. (Note that MEMORY_START is always 0 on 64-bit.)
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 28e61cc466 upstream.
If a transaction is rolled back, the Target Address Register (TAR), Processor
Priority Register (PPR) and Data Stream Control Register (DSCR) should be
restored to the checkpointed values before the transaction began. Any changes
to these SPRs inside the transaction should not be visible in the abort
handler.
Currently Linux doesn't save or restore the checkpointed TAR, PPR or DSCR. If
we preempt a processes inside a transaction which has modified any of these, on
process restore, that same transaction may be aborted we but we won't see the
checkpointed versions of these SPRs.
This adds checkpointed versions of these SPRs to the thread_struct and adds the
save/restore of these three SPRs to the treclaim/trechkpt code.
Without this if any of these SPRs are modified during a transaction, users may
incorrectly see a speculated SPR value even if the transaction is aborted.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c2d52644e2 upstream.
This moves us to save the Target Address Register (TAR) a earlier in
__switch_to. It introduces a new function save_tar() to do this.
We need to save the TAR earlier as we will overwrite it in the transactional
memory reclaim/recheckpoint path. We are going to do this in a subsequent
patch which will fix saving the TAR register when it's modified inside a
transaction.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2517617e0d upstream.
POWER8 allows the DSCR to be accessed directly from userspace via a new SPR
number 0x3 (Rather than 0x11. DSCR SPR number 0x11 is still used on POWER8 but
like POWER7, is only accessible in HV and OS modes). Currently, we allow this
by setting H/FSCR DSCR bit on boot.
Unfortunately this doesn't work, as the kernel needs to see the DSCR change so
that it knows to no longer restore the system wide version of DSCR on context
switch (ie. to set thread.dscr_inherit).
This clears the H/FSCR DSCR bit initially. If a process then accesses the DSCR
(via SPR 0x3), it'll trap into the kernel where we set thread.dscr_inherit in
facility_unavailable_exception().
We also change _switch() so that we set or clear the H/FSCR DSCR bit based on
the thread.dscr_inherit.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 74e400cee6 upstream.
This reworks the Facility Status and Control Regsiter (FSCR) config bit
definitions so that we can access the bit numbers. This is needed for a
subsequent patch to fix the userspace DSCR handling.
HFSCR and FSCR bit definitions are the same, so reuse them.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 88f094120b upstream.
Currently if we take hypervisor facility unavaliable (from 0xf80/0x4f80) we
mark it as an OS facility unavaliable (0xf60) as the two share the same code
path.
The becomes a problem in facility_unavailable_exception() as we aren't able to
see the hypervisor facility unavailable exceptions.
Below fixes this by duplication the required macros.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3be7db6ab4 upstream.
When an associativity level change is found for one thread, the
siblings threads need to be updated as well. This is done today
for PRRN in stage_topology_update() but is missing for VPHN in
update_cpu_associativity_changes_mask(). This patch will correctly
update all thread siblings during a topology change.
Without this patch a topology update can result in a CPU in
init_sched_groups_power() getting stuck indefinitely in a loop.
This loop is built in build_sched_groups(). As a result of the thread
moving to a node separate from its siblings the struct sched_group will
have its next pointer set to point to itself rather than the sched_group
struct of the next thread. This happens because we have a domain without
the SD_OVERLAP flag, which is correct, and a topology that doesn't conform
with reality (threads on the same core assigned to different numa nodes).
When this list is traversed by init_sched_groups_power() it will reach
the thread's sched_group structure and loop indefinitely; the cpu will
be stuck at this point.
The bug was exposed when VPHN was enabled in commit b7abef0 (v3.9).
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0e0ed6406e upstream.
Module CRCs are implemented as absolute symbols that get resolved by
a linker script. We build an intermediate .o that contains an
unresolved symbol for each CRC. genksysms parses this .o, calculates
the CRCs and writes a linker script that "resolves" the symbols to
the calculated CRC.
Unfortunately the ppc64 relocatable kernel sees these CRCs as symbols
that need relocating and relocates them at boot. Commit d4703aef
(module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y)
added a hook to reverse the bogus relocations. Part of this patch
created a symbol at 0x0:
# head -2 /proc/kallsyms
0000000000000000 T reloc_start
c000000000000000 T .__start
This reloc_start symbol is causing lots of confusion to perf. It
thinks reloc_start is a massive function that stretches from 0x0 to
0xc000000000000000 and we get various cryptic errors out of perf,
including:
problem incrementing symbol count, skipping event
This patch removes the reloc_start linker script label and instead
defines it as PHYSICAL_START. We also need to wrap it with
CONFIG_PPC64 because the ppc32 kernel can set a non zero
PHYSICAL_START at compile time and we wouldn't want to subtract
it from the CRCs in that case.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4ea355b536 upstream.
In power_pmu_enable() we still enable the PMU even if we have zero
events. This should have no effect but doesn't make much sense. Instead
just return after telling the hypervisor that we are not using the PMCs.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7a7a41f9d5 upstream.
On Power8 we can freeze PMC5 and 6 if we're not using them. Normally they
run all the time.
As noticed by Anshuman, we should unfreeze them when we disable the PMU
as there are legacy tools which expect them to run all the time.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 378a6ee99e upstream.
In pmu_disable() we disable the PMU by setting the FC (Freeze Counters)
bit in MMCR0. In order to do this we have to read/modify/write MMCR0.
It's possible that we read a value from MMCR0 which has PMAO (PMU Alert
Occurred) set. When we write that value back it will cause an interrupt
to occur. We will then end up in the PMU interrupt handler even though
we are supposed to have just disabled the PMU.
We can avoid this by making sure we never write PMAO back. We should not
lose interrupts because when the PMU is re-enabled the overflowed values
will cause another interrupt.
We also reorder the clearing of SAMPLE_ENABLE so that is done after the
PMU is frozen. Otherwise there is a small window between the clearing of
SAMPLE_ENABLE and the setting of FC where we could take an interrupt and
incorrectly see SAMPLE_ENABLE not set. This would for example change the
logic in perf_read_regs().
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d8bec4c9cd upstream.
A mistake we have made in the past is that we pull out the fields we
need from the event code, but don't check that there are no unknown bits
set. This means that we can't ever assign meaning to those unknown bits
in future.
Although we have once again failed to do this at release, it is still
early days for Power8 so I think we can still slip this in and get away
with it.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dd023217e1 upstream.
The topology update code that updates the cpu node registration in sysfs
should not be called while in stop_machine(). The register/unregister
calls take a lock and may sleep.
This patch moves these calls outside of the call to stop_machine().
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8246aca705 upstream.
the smp_release_cpus is a normal funciton and called in normal environments,
but it calls the __initdata spinning_secondaries.
need modify spinning_secondaries to match smp_release_cpus.
the related warning:
(the linker report boot_paca.33377, but it should be spinning_secondaries)
-----------------------------------------------------------------------------
WARNING: arch/powerpc/kernel/built-in.o(.text+0x23176): Section mismatch in reference from the function .smp_release_cpus() to the variable .init.data:boot_paca.33377
The function .smp_release_cpus() references
the variable __initdata boot_paca.33377.
This is often because .smp_release_cpus lacks a __initdata
annotation or the annotation of boot_paca.33377 is wrong.
WARNING: arch/powerpc/kernel/built-in.o(.text+0x231fe): Section mismatch in reference from the function .smp_release_cpus() to the variable .init.data:boot_paca.33377
The function .smp_release_cpus() references
the variable __initdata boot_paca.33377.
This is often because .smp_release_cpus lacks a __initdata
annotation or the annotation of boot_paca.33377 is wrong.
-----------------------------------------------------------------------------
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b14b6260ef upstream.
Similar to the facility unavailble exception, except the facilities are
controlled by HFSCR.
Adapt the facility_unavailable_exception() so it can be called for
either the regular or Hypervisor facility unavailable exceptions.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 021424a1fc upstream.
The exception at 0xf60 is not the TM (Transactional Memory) unavailable
exception, it is the "Facility Unavailable Exception", rename it as
such.
Flesh out the handler to acknowledge the fact that it can be called for
many reasons, one of which is TM being unavailable.
Use STD_EXCEPTION_COMMON() for the exception body, for some reason we
had it open-coded, I've checked the generated code is identical.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c9f69518e5 upstream.
KVMTEST is a macro which checks whether we are taking an exception from
guest context, if so we branch out of line and eventually call into the
KVM code to handle the switch.
When running real guests on bare metal (HV KVM) the hardware ensures
that we never take a relocation on exception when transitioning from
guest to host. For PR KVM we disable relocation on exceptions ourself in
kvmppc_core_init_vm(), as of commit a413f47 "Disable relocation on
exceptions whenever PR KVM is active".
So convert all the RELON macros to use NOTEST, and drop the remaining
KVM_HANDLER() definitions we have for 0xe40 and 0xe80.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1d567cb4bd upstream.
We have relocation on exception handlers defined for h_data_storage and
h_instr_storage. However we will never take relocation on exceptions for
these because they can only come from a guest, and we never take
relocation on exceptions when we transition from guest to host.
We also have a handler for hmi_exception (Hypervisor Maintenance) which
is defined in the architecture to never be delivered with relocation on,
see see v2.07 Book III-S section 6.5.
So remove the handlers, leaving a branch to self just to be double extra
paranoid.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 87b4e5393a upstream.
Currently we only restore signals which are transactionally suspended but it's
possible that the transaction can be restored even when it's active. Most
likely this will result in a transactional rollback by the hardware as the
transaction will have been doomed by an earlier treclaim.
The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel. That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
assumptions based on having software rollback.
This changes the signal return code to always restore both contexts on 64 bit
signal return. It also ensures that the MSR TM bits are properly restored from
the signal context which they are not currently.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 55e4341850 upstream.
Currently we only restore signals which are transactionally suspended but it's
possible that the transaction can be restored even when it's active. Most
likely this will result in a transactional rollback by the hardware as the
transaction will have been doomed by an earlier treclaim.
The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel. That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
assumptions based on having software rollback.
This changes the signal return code to always restore both contexts on 32 bit
rt signal return.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2c27a18f87 upstream.
Currently we clear out the MSR TM bits on signal return assuming that the
signal should never return to an active transaction.
This is bogus as the user may do this. It's most likely the transaction will
be doomed due to a treclaim but that's a problem for the HW not the kernel.
The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel. That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
the assumption that it must be returning to a suspended transaction.
This pulls out both MSR TM bits from the user supplied context rather than just
setting TM suspend. We pull out only the bits needed to ensure the user can't
do anything dangerous to the MSR.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fee5545071 upstream.
Currently sys_sigreturn() is TM unaware. Therefore, if we take a 32 bit signal
without SIGINFO (non RT) inside a transaction, on signal return we don't
restore the signal frame correctly.
This checks if the signal frame being restoring is an active transaction, and
if so, it copies the additional state to ptregs so it can be restored.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1d25f11fdb upstream.
The MSR TM controls are in the top 32 bits of the MSR hence on 32 bit signals,
we stick the top half of the MSR in the checkpointed signal context so that the
user can access it.
Unfortunately, we don't currently write anything to the checkpointed signal
context when coming in a from a non transactional process and hence the top MSR
bits can contain junk.
This updates the 32 bit signal handling code to always write something to the
top MSR bits so that users know if the process is transactional or not and the
kernel can use it on signal return.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 74251fe21b upstream.
So because those things always end up in trainwrecks... In 7846de406
we moved back the iommu initialization earlier, essentially undoing
37f02195b which was causing us endless trouble... except that in the
meantime we had merged 959c9bdd58 (to workaround the original breakage)
which is now ... broken :-)
This fixes it by doing a partial revert of the latter (we keep the
ppc_md. path which will be needed in the hotplug case, which happens
also during some EEH error recovery situations).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e2a800beac upstream.
The Data Address Watchpoint Register (DAWR) on POWER8 can take a 512
byte range but this range must not cross a 512 byte boundary.
Unfortunately we were off by one when calculating the end of the region,
hence we were not allowing some breakpoint regions which were actually
valid. This fixes this error.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reported-by: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 540e07c67e upstream.
In 9422de3 "powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint
registers" we changed the way we mark extraneous irqs with this:
- info->extraneous_interrupt = !((bp->attr.bp_addr <= dar) &&
- (dar - bp->attr.bp_addr < bp->attr.bp_len));
+ if (!((bp->attr.bp_addr <= dar) &&
+ (dar - bp->attr.bp_addr < bp->attr.bp_len)))
+ info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
Unfortunately this is bogus as it never clears extraneous IRQ if it's already
set.
This correctly clears extraneous IRQ before possibly setting it.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reported-by: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b0b0aa9c7f upstream.
The smallest match region for both the DABR and DAWR is 8 bytes, so the
kernel needs to filter matches when users want to look at regions smaller than
this.
Currently we set the length of PPC_BREAKPOINT_MODE_EXACT breakpoints to 8.
This is wrong as in exact mode we should only match on 1 address, hence the
length should be 1.
This ensures that the kernel will filter out any exact mode hardware breakpoint
matches on any addresses other than the requested one.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reported-by: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While running Linux as guest on top of phyp, we possiblly have
PE that includes single PCI device. However, we didn't return
its PCI bus correctly and it leads to failure on recovery from
EEH errors for single-dev-PE. The patch fixes the issue.
Cc: <stable@vger.kernel.org> # v3.7+
Cc: Steve Best <sbest@us.ibm.com>
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull powerpc fixes from Ben Herrenschmidt:
"We discovered some breakage in our "EEH" (PCI Error Handling) code
while doing error injection, due to a couple of regressions. One of
them is due to a patch (37f02195be "powerpc/pci: fix PCI-e devices
rescan issue on powerpc platform") that, in hindsight, I shouldn't
have merged considering that it caused more problems than it solved.
Please pull those two fixes. One for a simple EEH address cache
initialization issue. The other one is a patch from Guenter that I
had originally planned to put in 3.11 but which happens to also fix
that other regression (a kernel oops during EEH error handling and
possibly hotplug).
With those two, the couple of test machines I've hammered with error
injection are remaining up now. EEH appears to still fail to recover
on some devices, so there is another problem that Gavin is looking
into but at least it's no longer crashing the kernel."
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/pci: Improve device hotplug initialization
powerpc/eeh: Add eeh_dev to the cache during boot
Commit 37f02195b (powerpc/pci: fix PCI-e devices rescan issue on powerpc
platform) fixes a problem with interrupt and DMA initialization on hot
plugged devices. With this commit, interrupt and DMA initialization for
hot plugged devices is handled in the pci device enable function.
This approach has a couple of drawbacks. First, it creates two code paths
for device initialization, one for hot plugged devices and another for devices
known during the initial PCI scan. Second, the initialization code for hot
plugged devices is only called when the device is enabled, ie typically
in the probe function. Also, the platform specific setup code is called each
time pci_enable_device() is called, not only once during device discovery,
meaning it is actually called multiple times, once for devices discovered
during the initial scan and again each time a driver is re-loaded.
The visible result is that interrupt pins are only assigned to hot plugged
devices when the device driver is loaded. Effectively this changes the PCI
probe API, since pci_dev->irq and the device's dma configuration will now
only be valid after pci_enable() was called at least once. A more subtle
change is that platform specific PCI device setup is moved from device
discovery into the driver's probe function, more specifically into the
pci_enable_device() call.
To fix the inconsistencies, add new function pcibios_add_device.
Call pcibios_setup_device from pcibios_setup_bus_devices if device setup
is not complete, and from pcibios_add_device if bus setup is complete.
With this change, device setup code is moved back into device initialization,
and called exactly once for both static and hot plugged devices.
[ This also fixes a regression introduced by the above patch which
causes dev->irq to be overwritten under some cirumstances after
MSIs have been enabled for the device which leads to crashes due
to the MSI core "hijacking" dev->irq to store the base MSI number
and not the LSI. --BenH
]
Cc: Yuanquan Chen <Yuanquan.Chen@freescale.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Hiroo Matsumoto <matsumoto.hiroo@jp.fujitsu.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
