Commit b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8
SPRs") added a definition of KVM_REG_PPC_WORT with the same register
number as the existing KVM_REG_PPC_VRSAVE (though in fact the
definitions are not identical because of the different register sizes.)
For clarity, this moves KVM_REG_PPC_WORT to the next unused number,
and also adds it to api.txt.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
We worked around some nasty KVM magic page hcall breakages:
1) NX bit not honored, so ignore NX when we detect it
2) LE guests swizzle hypercall instruction
Without these fixes in place, there's no way it would make sense to expose kvm
hypercalls to a guest. Chances are immensely high it would trip over and break.
So add a new CAP that gives user space a hint that we have workarounds for the
bugs above in place. It can use those as hint to disable PV hypercalls when
the guest CPU is anything POWER7 or higher and the host does not have fixes
in place.
Signed-off-by: Alexander Graf <agraf@suse.de>
When we reset the in-kernel MPIC controller, we forget to reset some hidden
state such as destmask and output. This state is usually set when the guest
writes to the IDR register for a specific IRQ line.
To make sure we stay in sync and don't forget hidden state, treat reset of
the IDR register as a simple write of the IDR register. That automatically
updates all the hidden state as well.
Reported-by: Paul Janzen <pcj@pauljanzen.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
There are LE Linux guests out there that don't handle hypercalls correctly.
Instead of interpreting the instruction stream from device tree as big endian
they assume it's a little endian instruction stream and fail.
When we see an illegal instruction from such a byte reversed instruction stream,
bail out graciously and just declare every hcall as error.
Signed-off-by: Alexander Graf <agraf@suse.de>
We get an array of instructions from the hypervisor via device tree that
we write into a buffer that gets executed whenever we want to make an
ePAPR compliant hypercall.
However, the hypervisor passes us these instructions in BE order which
we have to manually convert to LE when we want to run them in LE mode.
With this fixup in place, I can successfully run LE kernels with KVM
PV enabled on PR KVM.
Signed-off-by: Alexander Graf <agraf@suse.de>
Use make_dsisr instead of open coding it. This also have
the added benefit of handling alignment interrupt on additional
instructions.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Although it's optional, IBM POWER cpus always had DAR value set on
alignment interrupt. So don't try to compute these values.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Because old kernels enable the magic page and then choke on NXed trampoline
code we have to disable NX by default in KVM when we use the magic page.
However, since commit b18db0b8 we have successfully fixed that and can now
leave NX enabled, so tell the hypervisor about this.
Signed-off-by: Alexander Graf <agraf@suse.de>
Old guests try to use the magic page, but map their trampoline code inside
of an NX region.
Since we can't fix those old kernels, try to detect whether the guest is sane
or not. If not, just disable NX functionality in KVM so that old guests at
least work at all. For newer guests, add a bit that we can set to keep NX
functionality available.
Signed-off-by: Alexander Graf <agraf@suse.de>
On recent IBM Power CPUs, while the hashed page table is looked up using
the page size from the segmentation hardware (i.e. the SLB), it is
possible to have the HPT entry indicate a larger page size. Thus for
example it is possible to put a 16MB page in a 64kB segment, but since
the hash lookup is done using a 64kB page size, it may be necessary to
put multiple entries in the HPT for a single 16MB page. This
capability is called mixed page-size segment (MPSS). With MPSS,
there are two relevant page sizes: the base page size, which is the
size used in searching the HPT, and the actual page size, which is the
size indicated in the HPT entry. [ Note that the actual page size is
always >= base page size ].
We use "ibm,segment-page-sizes" device tree node to advertise
the MPSS support to PAPR guest. The penc encoding indicates whether
we support a specific combination of base page size and actual
page size in the same segment. We also use the penc value in the
LP encoding of HPTE entry.
This patch exposes MPSS support to KVM guest by advertising the
feature via "ibm,segment-page-sizes". It also adds the necessary changes
to decode the base page size and the actual page size correctly from the
HPTE entry.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Today when KVM tries to reserve memory for the hash page table it
allocates from the normal page allocator first. If that fails it
falls back to CMA's reserved region. One of the side effects of
this is that we could end up exhausting the page allocator and
get linux into OOM conditions while we still have plenty of space
available in CMA.
This patch addresses this issue by first trying hash page table
allocation from CMA's reserved region before falling back to the normal
page allocator. So if we run out of memory, we really are out of memory.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
POWER8 introduces transactional memory which brings along a number of new
registers and MSR bits.
Implementing all of those is a pretty big headache, so for now let's at least
emulate enough to make Linux's context switching code happy.
Signed-off-by: Alexander Graf <agraf@suse.de>
POWER8 introduces a new facility called the "Event Based Branch" facility.
It contains of a few registers that indicate where a guest should branch to
when a defined event occurs and it's in PR mode.
We don't want to really enable EBB as it will create a big mess with !PR guest
mode while hardware is in PR and we don't really emulate the PMU anyway.
So instead, let's just leave it at emulation of all its registers.
Signed-off-by: Alexander Graf <agraf@suse.de>
POWER8 implements a new register called TAR. This register has to be
enabled in FSCR and then from KVM's point of view is mere storage.
This patch enables the guest to use TAR.
Signed-off-by: Alexander Graf <agraf@suse.de>
POWER8 introduced a new interrupt type called "Facility unavailable interrupt"
which contains its status message in a new register called FSCR.
Handle these exits and try to emulate instructions for unhandled facilities.
Follow-on patches enable KVM to expose specific facilities into the guest.
Signed-off-by: Alexander Graf <agraf@suse.de>
In parallel to the Processor ID Register (PIR) threaded POWER8 also adds a
Thread ID Register (TIR). Since PR KVM doesn't emulate more than one thread
per core, we can just always expose 0 here.
Signed-off-by: Alexander Graf <agraf@suse.de>
When we expose a POWER8 CPU into the guest, it will start accessing PMU SPRs
that we don't emulate. Just ignore accesses to them.
Signed-off-by: Alexander Graf <agraf@suse.de>
With the previous patches applied, we can now successfully use PR KVM on
little endian hosts which means we can now allow users to select it.
However, HV KVM still needs some work, so let's keep the kconfig conflict
on that one.
Signed-off-by: Alexander Graf <agraf@suse.de>
When the host CPU we're running on doesn't support dcbz32 itself, but the
guest wants to have dcbz only clear 32 bytes of data, we loop through every
executable mapped page to search for dcbz instructions and patch them with
a special privileged instruction that we emulate as dcbz32.
The only guests that want to see dcbz act as 32byte are book3s_32 guests, so
we don't have to worry about little endian instruction ordering. So let's
just always search for big endian dcbz instructions, also when we're on a
little endian host.
Signed-off-by: Alexander Graf <agraf@suse.de>
The shared (magic) page is a data structure that contains often used
supervisor privileged SPRs accessible via memory to the user to reduce
the number of exits we have to take to read/write them.
When we actually share this structure with the guest we have to maintain
it in guest endianness, because some of the patch tricks only work with
native endian load/store operations.
Since we only share the structure with either host or guest in little
endian on book3s_64 pr mode, we don't have to worry about booke or book3s hv.
For booke, the shared struct stays big endian. For book3s_64 hv we maintain
the struct in host native endian, since it never gets shared with the guest.
For book3s_64 pr we introduce a variable that tells us which endianness the
shared struct is in and route every access to it through helper inline
functions that evaluate this variable.
Signed-off-by: Alexander Graf <agraf@suse.de>
We expose a blob of hypercall instructions to user space that it gives to
the guest via device tree again. That blob should contain a stream of
instructions necessary to do a hypercall in big endian, as it just gets
passed into the guest and old guests use them straight away.
Signed-off-by: Alexander Graf <agraf@suse.de>
When the guest does an RTAS hypercall it keeps all RTAS variables inside a
big endian data structure.
To make sure we don't have to bother about endianness inside the actual RTAS
handlers, let's just convert the whole structure to host endian before we
call our RTAS handlers and back to big endian when we return to the guest.
Signed-off-by: Alexander Graf <agraf@suse.de>
The HTAB on PPC is always in big endian. When we access it via hypercalls
on behalf of the guest and we're running on a little endian host, we need
to make sure we swap the bits accordingly.
Signed-off-by: Alexander Graf <agraf@suse.de>
The default MSR when user space does not define anything should be identical
on little and big endian hosts, so remove MSR_LE from it.
Signed-off-by: Alexander Graf <agraf@suse.de>
The "shadow SLB" in the PACA is shared with the hypervisor, so it has to
be big endian. We access the shadow SLB during world switch, so let's make
sure we access it in big endian even when we're on a little endian host.
Signed-off-by: Alexander Graf <agraf@suse.de>
The HTAB is always big endian. We access the guest's HTAB using
copy_from/to_user, but don't yet take care of the fact that we might
be running on an LE host.
Wrap all accesses to the guest HTAB with big endian accessors.
Signed-off-by: Alexander Graf <agraf@suse.de>
The HTAB is always big endian. We access the guest's HTAB using
copy_from/to_user, but don't yet take care of the fact that we might
be running on an LE host.
Wrap all accesses to the guest HTAB with big endian accessors.
Signed-off-by: Alexander Graf <agraf@suse.de>
Commit 9308ab8e2d made C/R HTAB updates go byte-wise into the target HTAB.
However, it didn't update the guest's copy of the HTAB, but instead the
host local copy of it.
Write to the guest's HTAB instead.
Signed-off-by: Alexander Graf <agraf@suse.de>
CC: Paul Mackerras <paulus@samba.org>
Acked-by: Paul Mackerras <paulus@samba.org>
This patch make sure we inherit the LE bit correctly in different case
so that we can run Little Endian distro in PR mode
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The dcbtls instruction is able to lock data inside the L1 cache.
We don't want to give the guest actual access to hardware cache locks,
as that could influence other VMs on the same system. But we can tell
the guest that its locking attempt failed.
By implementing the instruction we at least don't give the guest a
program exception which it definitely does not expect.
Signed-off-by: Alexander Graf <agraf@suse.de>
The L1 instruction cache control register contains bits that indicate
that we're still handling a request. Mask those out when we set the SPR
so that a read doesn't assume we're still doing something.
Signed-off-by: Alexander Graf <agraf@suse.de>
Commit 8f619b5429 ("powerpc/ppc64: Do not turn AIL (reloc-on
interrupts) too early") added code to set the AIL bit in the LPCR
without checking whether the kernel is running in hypervisor mode. The
result is that when the kernel is running as a guest (i.e., under
PowerKVM or PowerVM), the processor takes a privileged instruction
interrupt at that point, causing a panic. The visible result is that
the kernel hangs after printing "returning from prom_init".
This fixes it by checking for hypervisor mode being available before
setting LPCR. If we are not in hypervisor mode, we enable relocation-on
interrupts later in pSeries_setup_arch using the H_SET_MODE hcall.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs updates from Al Viro:
"The first vfs pile, with deep apologies for being very late in this
window.
Assorted cleanups and fixes, plus a large preparatory part of iov_iter
work. There's a lot more of that, but it'll probably go into the next
merge window - it *does* shape up nicely, removes a lot of
boilerplate, gets rid of locking inconsistencie between aio_write and
splice_write and I hope to get Kent's direct-io rewrite merged into
the same queue, but some of the stuff after this point is having
(mostly trivial) conflicts with the things already merged into
mainline and with some I want more testing.
This one passes LTP and xfstests without regressions, in addition to
usual beating. BTW, readahead02 in ltp syscalls testsuite has started
giving failures since "mm/readahead.c: fix readahead failure for
memoryless NUMA nodes and limit readahead pages" - might be a false
positive, might be a real regression..."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
missing bits of "splice: fix racy pipe->buffers uses"
cifs: fix the race in cifs_writev()
ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
kill generic_file_buffered_write()
ocfs2_file_aio_write(): switch to generic_perform_write()
ceph_aio_write(): switch to generic_perform_write()
xfs_file_buffered_aio_write(): switch to generic_perform_write()
export generic_perform_write(), start getting rid of generic_file_buffer_write()
generic_file_direct_write(): get rid of ppos argument
btrfs_file_aio_write(): get rid of ppos
kill the 5th argument of generic_file_buffered_write()
kill the 4th argument of __generic_file_aio_write()
lustre: don't open-code kernel_recvmsg()
ocfs2: don't open-code kernel_recvmsg()
drbd: don't open-code kernel_recvmsg()
constify blk_rq_map_user_iov() and friends
lustre: switch to kernel_sendmsg()
ocfs2: don't open-code kernel_sendmsg()
take iov_iter stuff to mm/iov_iter.c
process_vm_access: tidy up a bit
...
Pull audit updates from Eric Paris.
* git://git.infradead.org/users/eparis/audit: (28 commits)
AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC
audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range
audit: do not cast audit_rule_data pointers pointlesly
AUDIT: Allow login in non-init namespaces
audit: define audit_is_compat in kernel internal header
kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c
sched: declare pid_alive as inline
audit: use uapi/linux/audit.h for AUDIT_ARCH declarations
syscall_get_arch: remove useless function arguments
audit: remove stray newline from audit_log_execve_info() audit_panic() call
audit: remove stray newlines from audit_log_lost messages
audit: include subject in login records
audit: remove superfluous new- prefix in AUDIT_LOGIN messages
audit: allow user processes to log from another PID namespace
audit: anchor all pid references in the initial pid namespace
audit: convert PPIDs to the inital PID namespace.
pid: get pid_t ppid of task in init_pid_ns
audit: rename the misleading audit_get_context() to audit_take_context()
audit: Add generic compat syscall support
audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
...
- Fix for a recently introduced CPU hotplug regression in ARM KVM
from Ming Lei.
- Fixes for breakage in the at32ap, loongson2_cpufreq, and unicore32
cpufreq drivers introduced during the 3.14 cycle (-stable material)
from Chen Gang and Viresh Kumar.
- New powernv cpufreq driver from Vaidyanathan Srinivasan, with bits
from Gautham R Shenoy and Srivatsa S Bhat.
- Exynos cpufreq driver fix preventing it from being included into
multiplatform builds that aren't supported by it from Sachin Kamat.
- cpufreq cleanups related to the usage of the driver_data field in
struct cpufreq_frequency_table from Viresh Kumar.
- cpufreq ppc driver cleanup from Sachin Kamat.
- Intel BayTrail support for intel_idle and ACPI idle from Len Brown.
- Intel CPU model 54 (Atom N2000 series) support for intel_idle from
Jan Kiszka.
- intel_idle fix for Intel Ivy Town residency targets from Len Brown.
- turbostat updates (Intel Broadwell support and output cleanups)
from Len Brown.
- New cpuidle sysfs attribute for exporting C-states' target residency
information to user space from Daniel Lezcano.
- New kernel command line argument to prevent power domains enabled
by the bootloader from being turned off even if they are not in use
(for diagnostics purposes) from Tushar Behera.
- Fixes for wakeup sysfs attributes documentation from Geert Uytterhoeven.
- New ACPI video blacklist entry for ThinkPad Helix from Stephen Chandler
Paul.
- Assorted ACPI cleanups and a Kconfig help update from Jonghwan Choi,
Zhihui Zhang, Hanjun Guo.
/
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Merge tag 'pm+acpi-3.15-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more ACPI and power management fixes and updates from Rafael Wysocki:
"This is PM and ACPI material that has emerged over the last two weeks
and one fix for a CPU hotplug regression introduced by the recent CPU
hotplug notifiers registration series.
Included are intel_idle and turbostat updates from Len Brown (these
have been in linux-next for quite some time), a new cpufreq driver for
powernv (that might spend some more time in linux-next, but BenH was
asking me so nicely to push it for 3.15 that I couldn't resist), some
cpufreq fixes and cleanups (including fixes for some silly breakage in
a couple of cpufreq drivers introduced during the 3.14 cycle),
assorted ACPI cleanups, wakeup framework documentation fixes, a new
sysfs attribute for cpuidle and a new command line argument for power
domains diagnostics.
Specifics:
- Fix for a recently introduced CPU hotplug regression in ARM KVM
from Ming Lei.
- Fixes for breakage in the at32ap, loongson2_cpufreq, and unicore32
cpufreq drivers introduced during the 3.14 cycle (-stable material)
from Chen Gang and Viresh Kumar.
- New powernv cpufreq driver from Vaidyanathan Srinivasan, with bits
from Gautham R Shenoy and Srivatsa S Bhat.
- Exynos cpufreq driver fix preventing it from being included into
multiplatform builds that aren't supported by it from Sachin Kamat.
- cpufreq cleanups related to the usage of the driver_data field in
struct cpufreq_frequency_table from Viresh Kumar.
- cpufreq ppc driver cleanup from Sachin Kamat.
- Intel BayTrail support for intel_idle and ACPI idle from Len Brown.
- Intel CPU model 54 (Atom N2000 series) support for intel_idle from
Jan Kiszka.
- intel_idle fix for Intel Ivy Town residency targets from Len Brown.
- turbostat updates (Intel Broadwell support and output cleanups)
from Len Brown.
- New cpuidle sysfs attribute for exporting C-states' target
residency information to user space from Daniel Lezcano.
- New kernel command line argument to prevent power domains enabled
by the bootloader from being turned off even if they are not in use
(for diagnostics purposes) from Tushar Behera.
- Fixes for wakeup sysfs attributes documentation from Geert
Uytterhoeven.
- New ACPI video blacklist entry for ThinkPad Helix from Stephen
Chandler Paul.
- Assorted ACPI cleanups and a Kconfig help update from Jonghwan
Choi, Zhihui Zhang, Hanjun Guo"
* tag 'pm+acpi-3.15-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (28 commits)
ACPI: Update the ACPI spec information in Kconfig
arm, kvm: fix double lock on cpu_add_remove_lock
cpuidle: sysfs: Export target residency information
cpufreq: ppc: Remove duplicate inclusion of fsl_soc.h
cpufreq: create another field .flags in cpufreq_frequency_table
cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table
cpufreq: don't print value of .driver_data from core
cpufreq: ia64: don't set .driver_data to index
cpufreq: powernv: Select CPUFreq related Kconfig options for powernv
cpufreq: powernv: Use cpufreq_frequency_table.driver_data to store pstate ids
cpufreq: powernv: cpufreq driver for powernv platform
cpufreq: at32ap: don't declare local variable as static
cpufreq: loongson2_cpufreq: don't declare local variable as static
cpufreq: unicore32: fix typo issue for 'clk'
cpufreq: exynos: Disable on multiplatform build
PM / wakeup: Correct presence vs. emptiness of wakeup_* attributes
PM / domains: Add pd_ignore_unused to keep power domains enabled
ACPI / dock: Drop dock_device_ids[] table
ACPI / video: Favor native backlight interface for ThinkPad Helix
ACPI / thermal: Fix wrong variable usage in debug statement
...
Pull more powerpc updates from Ben Herrenschmidt:
"Here are a few more powerpc things for you.
So you'll find here the conversion of the two new firmware sysfs
interfaces to the new API for self-removing files that Greg and Tejun
introduced, so they can finally remove the old one.
I'm also reverting the hwmon driver for powernv. I shouldn't have
merged it, I got a bit carried away here. I hadn't realized it was
never CCed to the relevant maintainer(s) and list(s), and happens to
have some issues so I'm taking it out and it will come back via the
proper channels.
The rest is a bunch of LE fixes (argh, some of the new stuff was
broken on LE, I really need to start testing LE myself !) and various
random fixes here and there.
Finally one bit that's not strictly a fix, which is the HVC OPAL
change to "kick" the HVC thread when the firmware tells us there is
new incoming data. I don't feel like waiting for this one, it's
simple enough, and it makes a big difference in console responsiveness
which is good for my nerves"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (26 commits)
powerpc/powernv Adapt opal-elog and opal-dump to new sysfs_remove_file_self
Revert "powerpc/powernv: hwmon driver for power values, fan rpm and temperature"
power, sched: stop updating inside arch_update_cpu_topology() when nothing to be update
powerpc/le: Avoid creatng R_PPC64_TOCSAVE relocations for modules.
arch/powerpc: Use RCU_INIT_POINTER(x, NULL) in platforms/cell/spu_syscalls.c
powerpc/opal: Add missing include
powerpc: Convert last uses of __FUNCTION__ to __func__
powerpc: Add lq/stq emulation
powerpc/powernv: Add invalid OPAL call
powerpc/powernv: Add OPAL message log interface
powerpc/book3s: Fix mc_recoverable_range buffer overrun issue.
powerpc: Remove dead code in sycall entry
powerpc: Use of_node_init() for the fakenode in msi_bitmap.c
powerpc/mm: NUMA pte should be handled via slow path in get_user_pages_fast()
powerpc/powernv: Fix endian issues with sensor code
powerpc/powernv: Fix endian issues with OPAL async code
tty/hvc_opal: Kick the HVC thread on OPAL console events
powerpc/powernv: Add opal_notifier_unregister() and export to modules
powerpc/ppc64: Do not turn AIL (reloc-on interrupts) too early
powerpc/ppc64: Gracefully handle early interrupts
...
We are currently using sysfs_schedule_callback() which is deprecated
and about to be removed. Switch to the new interface instead.
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Since v1:
Edited the comment according to Srivatsa's suggestion.
During the testing, we encounter below WARN followed by Oops:
WARNING: at kernel/sched/core.c:6218
...
NIP [c000000000101660] .build_sched_domains+0x11d0/0x1200
LR [c000000000101358] .build_sched_domains+0xec8/0x1200
PACATMSCRATCH [800000000000f032]
Call Trace:
[c00000001b103850] [c000000000101358] .build_sched_domains+0xec8/0x1200
[c00000001b1039a0] [c00000000010aad4] .partition_sched_domains+0x484/0x510
[c00000001b103aa0] [c00000000016d0a8] .rebuild_sched_domains+0x68/0xa0
[c00000001b103b30] [c00000000005cbf0] .topology_work_fn+0x10/0x30
...
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [c00000000045c000] .__bitmap_weight+0x60/0xf0
LR [c00000000010132c] .build_sched_domains+0xe9c/0x1200
PACATMSCRATCH [8000000000029032]
Call Trace:
[c00000001b1037a0] [c000000000288ff4] .kmem_cache_alloc_node_trace+0x184/0x3a0
[c00000001b103850] [c00000000010132c] .build_sched_domains+0xe9c/0x1200
[c00000001b1039a0] [c00000000010aad4] .partition_sched_domains+0x484/0x510
[c00000001b103aa0] [c00000000016d0a8] .rebuild_sched_domains+0x68/0xa0
[c00000001b103b30] [c00000000005cbf0] .topology_work_fn+0x10/0x30
...
This was caused by that 'sd->groups == NULL' after building groups, which
was caused by the empty 'sd->span'.
The cpu's domain contained nothing because the cpu was assigned to a wrong
node, due to the following unfortunate sequence of events:
1. The hypervisor sent a topology update to the guest OS, to notify changes
to the cpu-node mapping. However, the update was actually redundant - i.e.,
the "new" mapping was exactly the same as the old one.
2. Due to this, the 'updated_cpus' mask turned out to be empty after exiting
the 'for-loop' in arch_update_cpu_topology().
3. So we ended up calling stop-machine() with an empty cpumask list, which made
stop-machine internally elect cpumask_first(cpu_online_mask), i.e., CPU0 as
the cpu to run the payload (the update_cpu_topology() function).
4. This causes update_cpu_topology() to be run by CPU0. And since 'updates'
is kzalloc()'ed inside arch_update_cpu_topology(), update_cpu_topology()
finds update->cpu as well as update->new_nid to be 0. In other words, we
end up assigning CPU0 (and eventually its siblings) to node 0, incorrectly.
Along with the following wrong updating, it causes the sched-domain rebuild
code to break and crash the system.
Fix this by skipping the topology update in cases where we find that
the topology has not actually changed in reality (ie., spurious updates).
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: Nathan Fontenot <nfont@linux.vnet.ibm.com>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Robert Jennings <rcj@linux.vnet.ibm.com>
CC: Jesse Larrew <jlarrew@linux.vnet.ibm.com>
CC: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
CC: Alistair Popple <alistair@popple.id.au>
Suggested-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When building modules with a native le toolchain the linker will
generate R_PPC64_TOCSAVE relocations when it's safe to omit saving r2 on
a plt call. This isn't helpful in the conext of a kernel module and the
kernel will fail to load those modules with an error like:
nf_conntrack: Unknown ADD relocation: 109
This patch tells the linker to avoid createing R_PPC64_TOCSAVE
relocations allowing modules to load.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Here rcu_assign_pointer() is ensuring that the
initialization of a structure is carried out before storing a pointer
to that structure.
So, rcu_assign_pointer(p, NULL) can always safely be converted to
RCU_INIT_POINTER(p, NULL).
Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
next-20140324 currently fails compiling celleb_defconfig with:
arch/powerpc/include/asm/opal.h:894:42: error: 'struct notifier_block' declared inside parameter list [-Werror]
arch/powerpc/include/asm/opal.h:894:42: error: its scope is only this definition or declaration, which is probably not what you want [-Werror]
arch/powerpc/include/asm/opal.h:896:14: error: 'struct notifier_block' declared inside parameter list [-Werror]
This is due to a missing include which is added here.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Just about all of these have been converted to __func__,
so convert the last uses.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Recent CPUs support quad word load and store instructions. Add
support to the alignment handler for them.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This call will not be understood by OPAL, and cause it to add an error
to it's log. Among other things, this is useful for testing the
behaviour of the log as it fills up.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
OPAL provides an in-memory circular buffer containing a message log
populated with various runtime messages produced by the firmware.
Provide a sysfs interface /sys/firmware/opal/msglog for userspace to
view the messages.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently we wrongly allocate mc_recoverable_range buffer (to hold
recoverable ranges) based on size of the property "mcheck-recoverable-ranges".
This results in allocating less memory to hold available recoverable range
entries from /proc/device-tree/ibm,opal/mcheck-recoverable-ranges.
This patch fixes this issue by allocating mc_recoverable_range buffer based
on number of entries of recoverable ranges instead of device property size.
Without this change we end up allocating less memory and run into memory
corruption issue.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In:
commit 742415d6b6
Author: Michael Neuling <mikey@neuling.org>
powerpc: Turn syscall handler into macros
We converted the syscall entry code onto macros, but in doing this we
introduced some cruft that's never run and should never have been added.
This removes that code.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We need to handle numa pte via the slow path
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Paul Mackerras