This fixes a regression introduced by faa16bc404 ("lib: Use
existing define with polynomial").
The cleanup added a dependency on include/linux, which broke the PowerPC
boot wrapper/decompresser when KERNEL_XZ is enabled:
BOOTCC arch/powerpc/boot/decompress.o
In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:233,
from arch/powerpc/boot/decompress.c:42:
arch/powerpc/boot/../../../lib/xz/xz_crc32.c:18:10: fatal error:
linux/crc32poly.h: No such file or directory
#include <linux/crc32poly.h>
^~~~~~~~~~~~~~~~~~~
The powerpc decompresser is a hairy corner of the kernel. Even while building
a 64-bit kernel it needs to build a 32-bit binary and therefore avoid including
files from include/linux.
This allows users of the xz library to avoid including headers from
'include/linux/' while still achieving the cleanup of the magic number.
Fixes: faa16bc404 ("lib: Use existing define with polynomial")
Reported-by: Meelis Roos <mroos@linux.ee>
Reported-by: kbuild test robot <lkp@intel.com>
Suggested-by: Christophe LEROY <christophe.leroy@c-s.fr>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit b2d35fa5fc ("selftests: add headers_install to lib.mk")
introduced a requirement that Makefiles more than one level below the
selftests directory need to define top_srcdir, but it didn't update
any of the powerpc Makefiles.
This broke building all the powerpc selftests with eg:
make[1]: Entering directory '/src/linux/tools/testing/selftests/powerpc'
BUILD_TARGET=/src/linux/tools/testing/selftests/powerpc/alignment; mkdir -p $BUILD_TARGET; make OUTPUT=$BUILD_TARGET -k -C alignment all
make[2]: Entering directory '/src/linux/tools/testing/selftests/powerpc/alignment'
../../lib.mk:20: ../../../../scripts/subarch.include: No such file or directory
make[2]: *** No rule to make target '../../../../scripts/subarch.include'.
make[2]: Failed to remake makefile '../../../../scripts/subarch.include'.
Makefile:38: recipe for target 'alignment' failed
Fix it by setting top_srcdir in the affected Makefiles.
Fixes: b2d35fa5fc ("selftests: add headers_install to lib.mk")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Current we store the userspace r1 to PACATMSCRATCH before finally
saving it to the thread struct.
In theory an exception could be taken here (like a machine check or
SLB miss) that could write PACATMSCRATCH and hence corrupt the
userspace r1. The SLB fault currently doesn't touch PACATMSCRATCH, but
others do.
We've never actually seen this happen but it's theoretically
possible. Either way, the code is fragile as it is.
This patch saves r1 to the kernel stack (which can't fault) before we
turn MSR[RI] back on. PACATMSCRATCH is still used but only with
MSR[RI] off. We then copy r1 from the kernel stack to the thread
struct once we have MSR[RI] back on.
Suggested-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we treclaim we store the userspace checkpointed r13 to a scratch
SPR and then later save the scratch SPR to the user thread struct.
Unfortunately, this doesn't work as accessing the user thread struct
can take an SLB fault and the SLB fault handler will write the same
scratch SPRG that now contains the userspace r13.
To fix this, we store r13 to the kernel stack (which can't fault)
before we access the user thread struct.
Found by running P8 guest + powervm + disable_1tb_segments + TM. Seen
as a random userspace segfault with r13 looking like a kernel address.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
After migration of a powerpc LPAR, the kernel executes code to
update the system state to reflect new platform characteristics.
Such changes include modifications to device tree properties provided
to the system by PHYP. Property notifications received by the
post_mobility_fixup() code are passed along to the kernel in general
through a call to of_update_property() which in turn passes such
events back to all modules through entries like the '.notifier_call'
function within the NUMA module.
When the NUMA module updates its state, it resets its event timer. If
this occurs after a previous call to stop_topology_update() or on a
system without VPHN enabled, the code runs into an unitialized timer
structure and crashes. This patch adds a safety check along this path
toward the problem code.
An example crash log is as follows.
ibmvscsi 30000081: Re-enabling adapter!
------------[ cut here ]------------
kernel BUG at kernel/time/timer.c:958!
Oops: Exception in kernel mode, sig: 5 [#1]
LE SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: nfsv3 nfs_acl nfs tcp_diag udp_diag inet_diag lockd unix_diag af_packet_diag netlink_diag grace fscache sunrpc xts vmx_crypto pseries_rng sg binfmt_misc ip_tables xfs libcrc32c sd_mod ibmvscsi ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod
CPU: 11 PID: 3067 Comm: drmgr Not tainted 4.17.0+ #179
...
NIP mod_timer+0x4c/0x400
LR reset_topology_timer+0x40/0x60
Call Trace:
0xc0000003f9407830 (unreliable)
reset_topology_timer+0x40/0x60
dt_update_callback+0x100/0x120
notifier_call_chain+0x90/0x100
__blocking_notifier_call_chain+0x60/0x90
of_property_notify+0x90/0xd0
of_update_property+0x104/0x150
update_dt_property+0xdc/0x1f0
pseries_devicetree_update+0x2d0/0x510
post_mobility_fixup+0x7c/0xf0
migration_store+0xa4/0xc0
kobj_attr_store+0x30/0x60
sysfs_kf_write+0x64/0xa0
kernfs_fop_write+0x16c/0x240
__vfs_write+0x40/0x200
vfs_write+0xc8/0x240
ksys_write+0x5c/0x100
system_call+0x58/0x6c
Fixes: 5d88aa85c0 ("powerpc/pseries: Update CPU maps when device tree is updated")
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
scan_pkey_feature() uses of_property_read_u32_array() to read the
ibm,processor-storage-keys property and calls be32_to_cpu() on the
value it gets. The problem is that of_property_read_u32_array() already
returns the value converted to the CPU byte order.
The value of pkeys_total ends up more or less sane because there's a min()
call in pkey_initialize() which reduces pkeys_total to 32. So in practice
the kernel ignores the fact that the hypervisor reserved one key for
itself (the device tree advertises 31 keys in my test VM).
This is wrong, but the effect in practice is that when a process tries to
allocate the 32nd key, it gets an -EINVAL error instead of -ENOSPC which
would indicate that there aren't any keys available
Fixes: cf43d3b264 ("powerpc: Enable pkey subsystem")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On little endian platforms, csum_ipv6_magic() keeps len and proto in
CPU byte order. This generates a bad results leading to ICMPv6 packets
from other hosts being dropped by powerpc64le platforms.
In order to fix this, len and proto should be converted to network
byte order ie bigendian byte order. However checksumming 0x12345678
and 0x56341278 provide the exact same result so it is enough to
rotate the sum of len and proto by 1 byte.
PPC32 only support bigendian so the fix is needed for PPC64 only
Fixes: e9c4943a10 ("powerpc: Implement csum_ipv6_magic in assembly")
Reported-by: Jianlin Shi <jishi@redhat.com>
Reported-by: Xin Long <lucien.xin@gmail.com>
Cc: <stable@vger.kernel.org> # 4.18+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
mpe: This was fixed originally in commit d3d4ffaae4
("powerpc/powernv/ioda2: Reduce upper limit for DMA window size"), but
contrary to what the merge commit says was inadvertently lost by me in
commit ce57c6610c ("Merge branch 'topic/ppc-kvm' into next") which
brought in changes that moved the code to a new file. So reapply it to
the new file.
Original commit message follows:
We use PHB in mode1 which uses bit 59 to select a correct DMA window.
However there is mode2 which uses bits 59:55 and allows up to 32 DMA
windows per a PE.
Even though documentation does not clearly specify that, it seems that
the actual hardware does not support bits 59:55 even in mode1, in
other words we can create a window as big as 1<<58 but DMA simply
won't work.
This reduces the upper limit from 59 to 55 bits to let the userspace
know about the hardware limits.
Fixes: ce57c6610c ("Merge branch 'topic/ppc-kvm' into next")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Firmware-Assisted Dump (FADump) needs to be registered again after any
memory hot add/remove operation to update the crash memory ranges. But
currently, the kernel returns '-EEXIST' if we try to register without
uregistering it first. This could expose the system to racing issues
while unregistering and registering FADump from userspace during udev
events. Spare the userspace of this and let it be taken care of in the
kernel space for a simpler interface.
Since this change, running 'echo 1 > /sys/kernel/fadump_registered'
would result in re-regisering (unregistering and registering) FADump,
if it was already registered.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In lparcfg_write we hard code kbuf_sz and then use this as the variable
length of kbuf creating a variable length array. Since we're hard coding
the length anyway just define the array using this as the length and
remove the need for kbuf_sz, thus removing the variable length array.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In prom_check_platform_support() we retrieve and parse the
"ibm,arch-vec-5-platform-support" property of the chosen node.
Currently we use a variable length array however to avoid this use an
array of constant length 8.
This property is used to indicate the supported options of vector 5
bytes 23-26 of the ibm,architecture.vec node. Each of these options
is a pair of bytes, thus for 4 options we have a max length of 8 bytes.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This re-applies commit b91c1e3e7a ("powerpc: Fix duplicate const
clang warning in user access code") (Jun 2015) which was undone in
commits:
f2ca809059 ("powerpc/sparse: Constify the address pointer in __get_user_nosleep()") (Feb 2017)
d466f6c5ca ("powerpc/sparse: Constify the address pointer in __get_user_nocheck()") (Feb 2017)
f84ed59a61 ("powerpc/sparse: Constify the address pointer in __get_user_check()") (Feb 2017)
We see a large number of duplicate const errors in the user access
code when building with llvm/clang:
include/linux/pagemap.h:576:8: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
ret = __get_user(c, uaddr);
The problem is we are doing const __typeof__(*(ptr)), which will hit
the warning if ptr is marked const.
Removing const does not seem to have any effect on GCC code
generation.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When building with clang crt0's _zimage_start is not marked weak, which
breaks the build when linking the kernel image:
$ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
0000000000000058 g .text 0000000000000000 _zimage_start
ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start':
(.text+0x58): multiple definition of '_zimage_start';
arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here
Clang requires the .weak directive to appear after the symbol is
declared. The binutils manual says:
This directive sets the weak attribute on the comma separated list of
symbol names. If the symbols do not already exist, they will be
created.
So it appears this is different with clang. The only reference I could
see for this was an OpenBSD mailing list post[1].
Changing it to be after the declaration fixes building with Clang, and
still works with GCC.
$ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
0000000000000058 w .text 0000000000000000 _zimage_start
Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921
[1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Disable new features from recent releases, and clean out some other
unused options:
- Enable EXPERT, so we can disable some things
- Disable non-powerpc BPF decoders
- Disable TASKSTATS
- Disable unused syscalls
- Set more things to be modules
- Turn off unused network vendors
- PPC_OF_BOOT_TRAMPOLINE and FB_OF are unused on powernv
- Drop unused Radeon and Matrox GPU drivers
- IPV6 support landed in petitboot
- Bringup related command line powersave=off dropped, switch to quiet
Set CONFIG_I2C_CHARDEV=y as the module is not loaded automatically, and
without this i2cget etc. will fail in the skiroot environment.
This defconfig gets us build coverage of KERNEL_XZ, which was broken in
the 4.19 merge window for powerpc.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When performing partition migrations all present CPUs must be online
as all present CPUs must make the H_JOIN call as part of the migration
process. Once all present CPUs make the H_JOIN call, one CPU is returned
to make the rtas call to perform the migration to the destination system.
During testing of migration and changing the SMT state we have found
instances where CPUs are offlined, as part of the SMT state change,
before they make the H_JOIN call. This results in a hung system where
every CPU is either in H_JOIN or offline.
To prevent this this patch disables CPU hotplug during the migration
process.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There are three instances in which dlpar hotplug events are invoked;
handling a hotplug interrupt (in a kvm guest), handling a dlpar
request through sysfs, and updating LMB affinity when handling a
PRRN event. Only in the case of handling a hotplug interrupt do we
have to put the work on a workqueue, the other cases can handle the
dlpar request directly.
This patch exports the handle_dlpar_errorlog() function so that
dlpar hotplug events can be handled directly and updates the two
instances mentioned above to use the direct invocation.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The updates to powerpc numa and memory hotplug code now use the
in-kernel LMB array instead of the device tree. This change allows the
pseries memory DLPAR code to only update the device tree once after
successfully handling a DLPAR request.
Prior to the in-kernel LMB array, the numa code looked up the affinity
for memory being added in the device tree, the code now looks this up
in the LMB array. This change means the memory hotplug code can just
update the affinity for an LMB in the LMB array instead of updating
the device tree.
This also provides a savings in kernel memory. When updating the
device tree old properties are never free'ed since there is no
usecount on properties. This behavior leads to a new copy of the
property being allocated every time a LMB is added or removed (i.e. a
request to add 100 LMBs creates 100 new copies of the property). With
this update only a single new property is created when a DLPAR request
completes successfully.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
GCC 4.6 is the minimum supported now.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When switching processes, currently all user SLBEs are cleared, and a
few (exec_base, pc, and stack) are preloaded. In trivial testing with
small apps, this tends to miss the heap and low 256MB segments, and it
will also miss commonly accessed segments on large memory workloads.
Add a simple round-robin preload cache that just inserts the last SLB
miss into the head of the cache and preloads those at context switch
time. Every 256 context switches, the oldest entry is removed from the
cache to shrink the cache and require fewer slbmte if they are unused.
Much more could go into this, including into the SLB entry reclaim
side to track some LRU information etc, which would require a study of
large memory workloads. But this is a simple thing we can do now that
is an obvious win for common workloads.
With the full series, process switching speed on the context_switch
benchmark on POWER9/hash (with kernel speculation security masures
disabled) increases from 140K/s to 178K/s (27%).
POWER8 does not change much (within 1%), it's unclear why it does not
see a big gain like POWER9.
Booting to busybox init with 256MB segments has SLB misses go down
from 945 to 69, and with 1T segments 900 to 21. These could almost all
be eliminated by preloading a bit more carefully with ELF binary
loading.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This will be used by the SLB code in the next patch, but for now this
sets the slb_addr_limit to the correct size for 32-bit tasks.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add 32-entry bitmaps to track the allocation status of the first 32
SLB entries, and whether they are user or kernel entries. These are
used to allocate free SLB entries first, before resorting to the round
robin allocator.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
User SLB mappig data is copied into the PACA from the mm->context so
it can be accessed by the SLB miss handlers.
After the C conversion, SLB miss handlers now run with relocation on,
and user SLB misses are able to take recursive kernel SLB misses, so
the user SLB mapping data can be removed from the paca and accessed
directly.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch moves SLB miss handlers completely to C, using the standard
exception handler macros to set up the stack and branch to C.
This can be done because the segment containing the kernel stack is
always bolted, so accessing it with relocation on will not cause an
SLB exception.
Arbitrary kernel memory may not be accessed when handling kernel space
SLB misses, so care should be taken there. However user SLB misses can
access any kernel memory, which can be used to move some fields out of
the paca (in later patches).
User SLB misses could quite easily reconcile IRQs and set up a first
class kernel environment and exit via ret_from_except, however that
doesn't seem to be necessary at the moment, so we only do that if a
bad fault is encountered.
[ Credit to Aneesh for bug fixes, error checks, and improvements to bad
address handling, etc ]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Since RFC:
- Added MSR[RI] handling
- Fixed up a register loss bug exposed by irq tracing (Aneesh)
- Reject misses outside the defined kernel regions (Aneesh)
- Added several more sanity checks and error handling (Aneesh), we may
look at consolidating these tests and tightenig up the code but for
a first pass we decided it's better to check carefully.
Since v1:
- Fixed SLB cache corruption (Aneesh)
- Fixed untidy SLBE allocation "leak" in get_vsid error case
- Now survives some stress testing on real hardware
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 introduces SLBIA IH=3, which invalidates all SLB entries and
associated lookaside information that have a class value of 1, which
Linux assigns to user addresses. This matches what switch_slb wants,
and allows a simple fast implementation that avoids the slb_cache
complexity.
As a side-effect, the POWER5 < DD2.1 SLB invalidation workaround is
also avoided on POWER9.
Process context switching rate is improved about 2.2% for a small
process that hits the slb cache which is the best case for the current
code.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The SLBIA IH=1 hint will remove all non-zero SLBEs, but only
invalidate ERAT entries associated with a class value of 1, for
processors that support the hint (e.g., POWER6 and newer), which
Linux assigns to user addresses.
This prevents kernel ERAT entries from being invalidated when
context switchig (if the thread faulted in more than 8 user SLBEs).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Remove the vmalloc segment from bolted SLBEs. This is not required to
be bolted, and seems like it was added to help pre-load the SLB on
context switch. However there are now other segments like the vmemmap
segment and non-zero node memory that often take misses after a context
switch, so it is better to solve this in a more general way.
A subsequent change will track free SLB entries and uses those rather
than round-robin overwrite valid entries, which makes it far less
likely for kernel SLBEs to be evicted after they are installed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The POWER5 < DD2.1 issue is that slbie needs to be issued more than
once. It came in with this change:
ChangeSet@1.1608, 2004-04-29 07:12:31-07:00, david@gibson.dropbear.id.au
[PATCH] POWER5 erratum workaround
Early POWER5 revisions (<DD2.1) have a problem requiring slbie
instructions to be repeated under some circumstances. The patch below
adds a workaround (patch made by Anton Blanchard).
(aka. 3e4520f7605243abf66a7ccd3d2e49e48e8c0483 in the full history tree)
The extra slbie in switch_slb is done even for the case where slbia is
called (slb_flush_and_rebolt). I don't believe that is required
because there are other slb_flush_and_rebolt callers which do not
issue the workaround slbie, which would be broken if it was required.
It also seems to be fine inside the isync with the first slbie, as it
is in the kernel stack switch code.
So move this workaround to where it is required. This is not much of
an optimisation because this is the fast path, but it makes the code
more understandable and neater.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Retain slbie_data initialisation to avoid compiler warning]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
I only have POWER8/9 to test, so just remove it for those.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This causes SLB alloation to start 1 beyond the start of the SLB.
There is no real problem because after it wraps it stats behaving
properly, it's just surprisig to see when looking at SLB traces.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that other platforms also implements real mode mce handler,
lets consolidate the code by sharing existing powernv machine check
early code. Rename machine_check_powernv_early to
machine_check_common_early and reuse the code.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Extract the MCE error details from RTAS extended log and display it to
console.
With this patch you should now see mce logs like below:
[ 142.371818] Severe Machine check interrupt [Recovered]
[ 142.371822] NIP [d00000000ca301b8]: init_module+0x1b8/0x338 [bork_kernel]
[ 142.371822] Initiator: CPU
[ 142.371823] Error type: SLB [Multihit]
[ 142.371824] Effective address: d00000000ca70000
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On pseries, as of today system crashes if we get a machine check
exceptions due to SLB errors. These are soft errors and can be fixed
by flushing the SLBs so the kernel can continue to function instead of
system crash. We do this in real mode before turning on MMU. Otherwise
we would run into nested machine checks. This patch now fetches the
rtas error log in real mode and flushes the SLBs on SLB/ERAT errors.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On pseries, the machine check error details are part of RTAS extended
event log passed under Machine check exception section. This patch adds
the definition of rtas MCE event section and related helper
functions.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There are cases where the test is not expecting to have the transaction
aborted, but, the test process might have been rescheduled, either in the
OS level or by KVM (if it is running on a KVM guest machine). The process
reschedule will cause a treclaim/recheckpoint which will cause the
transaction to doom, aborting the transaction as soon as the process is
rescheduled back to the CPU. This might cause the test to fail, but this is
not a failure in essence.
If that is the case, TEXASR[FC] is indicated with either
TM_CAUSE_RESCHEDULE or TM_CAUSE_KVM_RESCHEDULE for KVM interruptions.
In this scenario, ignore these two failures and avoid the whole test to
return failure.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Gustavo Romero <gromero@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The tbl pointer is being derefenced by IOMMU_PAGE_SIZE prior the check
if it is not NULL.
Just moving the dereference code to after the check, where there will
be guarantee that 'tbl' will not be NULL.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Function xive_native_get_ipi() might use chip_id without it being
initialized, if the CPU node is not found, as reported by smatch:
error: uninitialized symbol 'chip_id'
As suggested by Cédric, we can use xc->chip_id instead of consulting
the device tree for chip id, which is safe since xive_prepare_cpu()
should have initialized ->chip_id by the time xive_native_get_ipi() is
called.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[mpe: Tweak change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The AFU Information DVSEC capability is a means to extract common,
general information about all of the AFUs associated with a Function
independent of the specific functionality that each AFU provides.
Write in the AFU Index field allows to access to the descriptor data
for each AFU.
With the current code, we are not able to access to these specific data
when the index >= 1 because we are writing to the wrong location.
All requests to the data of each AFU are pointing to those of the AFU 0,
which could have impacts when using a card with more than one AFU per
function.
This patch fixes the access to the AFU Descriptor Data indexed by the
AFU Info Index field.
Fixes: 5ef3166e8a ("ocxl: Driver code for 'generic' opencapi devices")
Cc: stable <stable@vger.kernel.org> # 4.16
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When hot-removing memory release_mem_region_adjustable() splits iomem
resources if they are not the exact size of the memory being
hot-deleted. Adding this memory back to the kernel adds a new resource.
Eg a node has memory 0x0 - 0xfffffffff. Hot-removing 1GB from
0xf40000000 results in the single resource 0x0-0xfffffffff being split
into two resources: 0x0-0xf3fffffff and 0xf80000000-0xfffffffff.
When we hot-add the memory back we now have three resources:
0x0-0xf3fffffff, 0xf40000000-0xf7fffffff, and 0xf80000000-0xfffffffff.
This is an issue if we try to remove some memory that overlaps
resources. Eg when trying to remove 2GB at address 0xf40000000,
release_mem_region_adjustable() fails as it expects the chunk of memory
to be within the boundaries of a single resource. We then get the
warning: "Unable to release resource" and attempting to use memtrace
again gives us this error: "bash: echo: write error: Resource
temporarily unavailable"
This patch makes memtrace remove memory in chunks that are always the
same size from an address that is always equal to end_of_memory -
n*size, for some n. So hotremoving and hotadding memory of different
sizes will now not attempt to remove memory that spans multiple
resources.
Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This stops us from doing code patching in init sections after they've
been freed.
In this chain:
kvm_guest_init() ->
kvm_use_magic_page() ->
fault_in_pages_readable() ->
__get_user() ->
__get_user_nocheck() ->
barrier_nospec();
We have a code patching location at barrier_nospec() and
kvm_guest_init() is an init function. This whole chain gets inlined,
so when we free the init section (hence kvm_guest_init()), this code
goes away and hence should no longer be patched.
We seen this as userspace memory corruption when using a memory
checker while doing partition migration testing on powervm (this
starts the code patching post migration via
/sys/kernel/mobility/migration). In theory, it could also happen when
using /sys/kernel/debug/powerpc/barrier_nospec.
Cc: stable@vger.kernel.org # 4.13+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Static branch hints override dynamic branch prediction on recent
POWER CPUs. We should only use them when we are overwhelmingly
sure of the direction.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This hypervisor's call allows to remove up to 8 ptes with only call to
tlbie.
The virtual pages must be all within the same naturally aligned 8 pages
virtual address block and have the same page and segment size encodings.
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This part of code will be called also when dealing with H_BLOCK_REMOVE.
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This feature tells if the hcall H_BLOCK_REMOVE is available.
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch simply fix part of the documentation on the HTM code.
This fixes reference to old fields that were renamed in commit
000ec280e3 ("powerpc: tm: Rename transct_(*) to ck(\1)_state")
It also documents better the flow after commit eb5c3f1c86 ("powerpc:
Always save/restore checkpointed regs during treclaim/trecheckpoint"),
where tm_recheckpoint can recheckpoint what is in ck{fp,vr}_state
blindly.
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
