Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
2.37.90.20220207) the following build error shows up:

  {standard input}: Assembler messages:
  {standard input}:1190: Error: unrecognized opcode: `stbcix'
  {standard input}:1433: Error: unrecognized opcode: `lwzcix'
  {standard input}:1453: Error: unrecognized opcode: `stbcix'
  {standard input}:1460: Error: unrecognized opcode: `stwcix'
  {standard input}:1596: Error: unrecognized opcode: `stbcix'
  ...

Rework to add assembler directives [1] around the instruction. Going
through them one by one shows that the changes should be safe.  Like
__get_user_atomic_128_aligned() is only called in p9_hmi_special_emu(),
which according to the name is specific to power9.  And __raw_rm_read*()
are only called in things that are powernv or book3s_hv specific.

[1] https://sourceware.org/binutils/docs/as/PowerPC_002dPseudo.html#PowerPC_002dPseudo



Cc: stable@vger.kernel.org
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
[mpe: Make commit subject more descriptive]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224162215.3406642-2-anders.roxell@linaro.org

Looks like there been a copy paste mistake when added the instruction
'stbcx' twice and one was probably meant to be 'sthcx'. Changing to
'sthcx' from 'stbcx'.

Fixes: 350779a2

 ("powerpc: Handle most loads and stores in instruction emulation code")
Cc: stable@vger.kernel.org # v4.14+
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224162215.3406642-1-anders.roxell@linaro.org

When CONFIG_GENERIC_CPU=y (true for all our defconfigs) we pass
-mcpu=powerpc64 to the compiler, even when we're building a 32-bit
kernel.

This happens because we have an ifdef CONFIG_PPC_BOOK3S_64/else block in
the Makefile that was written before 32-bit supported GENERIC_CPU. Prior
to that the else block only applied to 64-bit Book3E.

The GCC man page says -mcpu=powerpc64 "[specifies] a pure ... 64-bit big
endian PowerPC ... architecture machine [type], with an appropriate,
generic processor model assumed for scheduling purposes."

It's unclear how that interacts with -m32, which we are also passing,
although obviously -m32 is taking precedence in some sense, as the
32-bit kernel only contains 32-bit instructions.

This was noticed by inspection, not via any bug reports, but it does
affect code generation. Comparing before/after code generation, there
are some changes to instruction scheduling, and the after case (with
-mcpu=powerpc64 removed) the compiler seems more keen to use r8.

Fix it by making the else case only apply to Book3E 64, which excludes
32-bit.

Fixes: 0e00a8c9

 ("powerpc: Allow CPU selection also on PPC32")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220215112858.304779-1-mpe@ellerman.id.au

Executing node_set_online() when nid = NUMA_NO_NODE results in an
undefined behavior. node_set_online() will call node_set_state(), into
__node_set(), into set_bit(), and since NUMA_NO_NODE is -1 we'll end up
doing a negative shift operation inside
arch/powerpc/include/asm/bitops.h. This potential UB was detected
running a kernel with CONFIG_UBSAN.

The behavior was introduced by commit 10f78fd0 ("powerpc/numa: Fix a
regression on memoryless node 0"), where the check for nid > 0 was
removed to fix a problem that was happening with nid = 0, but the result
is that now we're trying to online NUMA_NO_NODE nids as well.

Checking for nid >= 0 will allow node 0 to be onlined while avoiding
this UB with NUMA_NO_NODE.

Fixes: 10f78fd0

 ("powerpc/numa: Fix a regression on memoryless node 0")
Reported-by: Ping Fang <pifang@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224182312.1012527-1-danielhb413@gmail.com

Since commit ceff77ef

 ("powerpc/64e/interrupt: Use new interrupt
context tracking scheme") struct interrupt_state has been empty and
unused.

Remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1d862ce3eab3da6ca7ac47d4a78a18f154462511.1645806970.git.christophe.leroy@csgroup.eu

Crash recovery (fadump) is setup in the userspace by some service. This
service rebuilds initrd with dump capture capability, if it is not
already dump capture capable before proceeding to register for firmware
assisted dump (echo 1 > /sys/kernel/fadump/registered). But arming the
kernel with crash recovery support does not have to wait for userspace
configuration. So, register for fadump while setting it up itself. This
can at worst lead to a scenario, where /proc/vmcore is ready afer crash
but the initrd does not know how/where to offload it, which is always
better than not having a /proc/vmcore at all due to incomplete
configuration in the userspace at the time of crash.

Commit 0823c68b

 ("powerpc/fadump: re-register firmware-assisted dump
if already registered") ensures this change does not break userspace.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
[mpe: Reword comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220201105305.155511-1-hbathini@linux.ibm.com

The testcase uses event code 0x35340401e0 to verify the settings for
different fields in Monitor Mode Control Register A (MMCRA). The fields
include thresh_start, thresh_stop thresh_select, sdar mode, sample and
marked bit. Checks if these fields are translated correctly via perf
interface to MMCRA.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-21-kjain@linux.ibm.com

The testcase uses event code 0x1340000001c040 to verify the settings for
different src fields in Monitor Mode Control Register 3 (MMCR3). Checks
if these fields are translated correctly via perf interface to MMCR3 on
ISA v3.1 platform.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-20-kjain@linux.ibm.com

The testcases uses cycles event to verify the freeze counter settings in
Monitor Mode Control Register 2 (MMCR2). Event modifier (exclude_kernel)
setting is used for the event attribute to check the FCxS and FCxH (
Freeze counter in privileged and hypervisor state ) settings via perf
interface.

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
[mpe: Add error checking, check MSR for MSR_HV, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-19-kjain@linux.ibm.com

The testcases uses event code 0x010000046080 to verify the l2l3 bit
setting for Monitor Mode Control Register 2 (MMCR2). check if this bit
is set correctly via perf interface in ISA v3.1 platform.

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-18-kjain@linux.ibm.com

The testcase uses event code "0x26880" to verify the settings for
different fields in Monitor Mode Control Register 1 (MMCR1). The field
include PMCxCOMB. Checks if this field are translated correctly via perf
interface to MMCR1

Add selftest for mmcr1 comb field.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-16-kjain@linux.ibm.com

The testcase uses event code 0x500fa to verify the FC5-6 bit setting in
Monitor Mode Control Register 0 (MMCR0). Check if FC5-6 bit is not set
in MMCR0 when using Performance Monitor Counter 5 and 6 (PMC5 and PMC6).

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-15-kjain@linux.ibm.com

The testcase uses event code 0x1001e to verify two bit settings (FC5-6
and PMC1CE) in Monitor Mode Control Register 0 (MMCR0). Check if FC5-6
bit to be set in MMCR0 when not using Performance Monitor Counter 5 and
6 (PMC5 and PMC6). And also PMC1CE is expected to be set when using
PMC1. Test if these fields are programmed correctly via perf interface.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-14-kjain@linux.ibm.com

The testcase uses event code 0x500fa ("instructions") to verify the
PMCjCE bit setting in Monitor Mode Control Register 0 (MMCR0). This bit
is expected to be set in MMCR0 when using Performance Monitor Counter
5 (PMC5). Checks if perf interface sets this bit correctly.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-13-kjain@linux.ibm.com

The testcase uses cycles event to check the PMCCEXT bit setting in
Monitor Mode Control Register 0 (MMCR0). Check if perf interface sets
this control bit in MMCR0 on ISA v3.1 platform.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-12-kjain@linux.ibm.com

The testcase uses event code 0x500fa ("instructions") to check the
CC56RUN bit setting in Monitor Mode Control Register 0(MMCR0). In ISA
v3.1 platform, this bit is expected to be set in MMCR0 when using
Performance Monitor Counter 5 and 6 (PMC5 and PMC6). Verify this is done
correctly by perf interface.

CC56RUN bit makes PMC5 and PMC6 count regardless of the run latch state.
This bit is set in power10 since PMC5 and PMC6 is used in power10 for
counting instructions and cycles. Hence added a check to skip this test
in other platforms

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-11-kjain@linux.ibm.com

The testcase uses "instructions" event to verify two bits(PMAE and PMAO)
in Monitor Mode Control Register 0 (MMCR0). At the time of interrupt,
pmae bit ( which enables performance monitor exception ) is expected to
be cleared and pmao (which indicates performance monitor alert) bit is
expected to be set in MMCR0. And testcases handles these checks.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-10-kjain@linux.ibm.com

Add macro and utility functions to fetch individual fields from Monitor
Mode Control Register 3(MMCR3)and Monitor Mode Control Register A(MMCRA)
PMU registers

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-9-kjain@linux.ibm.com

Add macro and utility functions to fetch individual fields from Monitor
Mode Control Register 0(MMCR0) and Monitor Mode Control Register
1(MMCR1) PMU register.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-8-kjain@linux.ibm.com

Along with it, Add macros and utility functions to fetch individual
fields from Monitor Mode Control Register 2(MMCR2) register.

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-7-kjain@linux.ibm.com

Extended event_init_opts() to include initialization of sampling
testcases. Patch adds an event_init_sampling() wrapper to initialize
event attribute fields for sampling events. This includes initializing
sample period, sample type and event type.

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-6-kjain@linux.ibm.com

Add couple of basic utility functions to post process the mmap buffer.
It includes function to read the total number of samples present in the
mmap buffer and function to get the address of the first sample.

Add function "get_intr_regs" which will return pointer to interrupt
registers present in the sample, incase sample type
PERF_SAMPLE_REGS_INTR is set.

Add functions "get_reg_value" which can be used to read any interrupt
register value from a given sample.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-5-kjain@linux.ibm.com

Each platform has raw event encoding format which specifies the bit
positions for different fields. The fields from event code gets
translated into performance monitoring mode control register (MMCRx)
settings. Patch add macros to extract individual fields from the event
code.

Add functions for sanity checks, since testcases currently are only
supported in power9 and power10.

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
[mpe: Read PVR directly rather than using /proc/cpuinfo]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-4-kjain@linux.ibm.com

Add support functions for enabling perf sampling test in a new folder
"sampling_tests" under "selftests/powerpc/pmu". This includes support
functions for allocating and processing the mmap buffer. These functions
are added/defined in "sampling_tests/misc.*" files.

Also updates the corresponding Makefiles in "selftests/powerpc" and
"sampling_tests" folder.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Drop unneeded bits from the Makefile]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-3-kjain@linux.ibm.com

To enable the capturing of samples as part of perf event, add a new
field "mmap_buffer" to "struct event". This field is a place-holder for
sample collection

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-2-kjain@linux.ibm.com

Fix following coccicheck warning:
./arch/powerpc/kernel/module_64.c:432:40-41: WARNING: Use ARRAY_SIZE.

ARRAY_SIZE(arr) is a macro provided by the kernel. It makes sure that arr
is an array, so it's safer than sizeof(arr) / sizeof(arr[0]) and more
standard.

Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220223075426.20939-1-guozhengkui@vivo.com

Hash faults are not resoved in NMI context, instead causing the access
to fail. This is done because perf interrupts can get backtraces
including walking the user stack, and taking a hash fault on those could
deadlock on the HPTE lock if the perf interrupt hits while the same HPTE
lock is being held by the hash fault code. The user-access for the stack
walking will notice the access failed and deal with that in the perf
code.

The reason to allow perf interrupts in is to better profile hash faults.

The problem with this is any hash fault on a kernel access that happens
in NMI context will crash, because kernel accesses must not fail.

Hard lockups, system reset, machine checks that access vmalloc space
including modules and including stack backtracing and symbol lookup in
modules, per-cpu data, etc could all run into this problem.

Fix this by disallowing perf interrupts in the hash fault code (the
direct hash fault is covered by MSR[EE]=0 so the PMI disable just needs
to extend to the preload case). This simplifies the tricky logic in hash
faults and perf, at the cost of reduced profiling of hash faults.

perf can still latch addresses when interrupts are disabled, it just
won't get the stack trace at that point, so it would still find hot
spots, just sometimes with confusing stack chains.

An alternative could be to allow perf interrupts here but always do the
slowpath stack walk if we are in nmi context, but that slows down all
perf interrupt stack walking on hash though and it does not remove as
much tricky code.

Reported-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220204035348.545435-1-npiggin@gmail.com

Following commit 12318163

 ("powerpc/32: Remove remaining .stabs
annotations"), stabs code are not used anymore.

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d8b33342d7454f6ca4f368f5206896558dfa06f4.1645538722.git.christophe.leroy@csgroup.eu

Presently PAPR doesn't support injecting smart errors on an
NVDIMM. This makes testing the NVDIMM health reporting functionality
difficult as simulating NVDIMM health related events need a hacked up
qemu version.

To solve this problem this patch proposes simulating certain set of
NVDIMM health related events in papr_scm. Specifically 'fatal' health
state and 'dirty' shutdown state. These error can be injected via the
user-space 'ndctl-inject-smart(1)' command. With the proposed patch and
corresponding ndctl patches following command flow is expected:

$ sudo ndctl list -DH -d nmem0
...
      "health_state":"ok",
      "shutdown_state":"clean",
...
 # inject unsafe shutdown and fatal health error
$ sudo ndctl inject-smart nmem0 -Uf
...
      "health_state":"fatal",
      "shutdown_state":"dirty",
...
 # uninject all errors
$ sudo ndctl inject-smart nmem0 -N
...
      "health_state":"ok",
      "shutdown_state":"clean",
...

The patch adds a new member 'health_bitmap_inject_mask' inside struct
papr_scm_priv which is then bitwise ANDed to the health bitmap fetched from the
hypervisor. The value for 'health_bitmap_inject_mask' is accessible from sysfs
at nmemX/papr/health_bitmap_inject.

A new PDSM named 'SMART_INJECT' is proposed that accepts newly
introduced 'struct nd_papr_pdsm_smart_inject' as payload thats
exchanged between libndctl and papr_scm to indicate the requested
smart-error states.

When the processing the PDSM 'SMART_INJECT', papr_pdsm_smart_inject()
constructs a pair or 'inject_mask' and 'clear_mask' bitmaps from the payload
and bit-blt it to the 'health_bitmap_inject_mask'. This ensures the after being
fetched from the hypervisor, the health_bitmap reflects requested smart-error
states.

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220124202204.1488346-1-vaibhav@linux.ibm.com

Add some line breaks to better match the file's style, add
some space after comma and fix a couple of misplaced blanks.

Suggested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/973506292d0c7b05c06530c8e11803ce38e5eda2.1644949750.git.christophe.leroy@csgroup.eu

When FL_SAVE_REGS is not set we get here via ftrace_caller()
which doesn't save all registers.

ftrace_caller() explicitely clears regs.msr, so we can rely
on it to know where we come from. We don't expect MSR register
to be 0 at all when involving ftrace.

Fixes: 40b035ef

 ("powerpc/ftrace: Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS")
Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2f9a7e898c93cc7438ef5ccd47cb9c3a9c5b53ef.1644949750.git.christophe.leroy@csgroup.eu

The function_graph_enter() does not provide any recursion protection.

Add a protection in prepare_ftrace_return() in case
function_graph_enter() calls something that gets
function graph traced.

Fixes: 83021378

 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller")
Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/74edf2ff0a60e66b0d9225a137100a86a0557032.1644949750.git.christophe.leroy@csgroup.eu

Also save r1 in ftrace_caller()

r1 is needed during unwinding when the function_graph tracer
is active.

Fixes: 83021378

 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller")
Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ff535e86d3a69376a6d89168511d4e403835f18b.1644949750.git.christophe.leroy@csgroup.eu

Currently, `git status` lists the file as untracked by git, so tell git
to ignore it.

Fixes: aa3bc365

 ("powerpc/ps3: Add check for otheros image size")
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220214065543.198992-1-pmenzel@molgen.mpg.de

Warnings in assembly must use EMIT_WARN_ENTRY in order to generate
the necessary entry in exception table.

Check in EMIT_BUG_ENTRY that flags don't include BUGFLAG_WARNING.

This change avoids problems like the one fixed by
commit fd1eaaaa

 ("powerpc/64s: Use EMIT_WARN_ENTRY for SRR debug
warnings").

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ddcb422102a37eb45f57694c7ef0ec6187964dff.1644742951.git.christophe.leroy@csgroup.eu

Our skiroot_defconfig doesn't enable FTRACE, and so doesn't get
STACKTRACE enabled either. That leads to a build failure since commit
1614b2b1 ("arch: Make ARCH_STACKWALK independent of STACKTRACE")
made stacktrace.c build even when STACKTRACE=n.

  arch/powerpc/kernel/stacktrace.c: In function ‘handle_backtrace_ipi’:
  arch/powerpc/kernel/stacktrace.c:171:2: error: implicit declaration of function ‘nmi_cpu_backtrace’
    171 |  nmi_cpu_backtrace(regs);
        |  ^~~~~~~~~~~~~~~~~
  arch/powerpc/kernel/stacktrace.c: In function ‘arch_trigger_cpumask_backtrace’:
  arch/powerpc/kernel/stacktrace.c:226:2: error: implicit declaration of function ‘nmi_trigger_cpumask_backtrace’
    226 |  nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi);
        |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This happens because our headers haven't defined
arch_trigger_cpumask_backtrace, which causes lib/nmi_backtrace.c not to
build nmi_cpu_backtrace().

The code in question doesn't actually depend on STACKTRACE=y, that was
just added because arch_trigger_cpumask_backtrace() lived in
stacktrace.c for convenience. So drop the dependency on
CONFIG_STACKTRACE, that causes lib/nmi_backtrace.c to build
nmi_cpu_backtrace() etc. and fixes the build.

Fixes: 1614b2b1

 ("arch: Make ARCH_STACKWALK independent of STACKTRACE")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220212111349.2806972-1-mpe@ellerman.id.au

commit: d9c23400

 ("Do not depend on MAX_ORDER when grouping pages by mobility")
introduced pageblock_order which will be used to group pages better.
The kernel now groups pages based on the value of HPAGE_SHIFT. Hence HPAGE_SHIFT
should be set before we call set_pageblock_order.

set_pageblock_order happens early in the boot and default hugetlb page size
should be initialized before that to compute the right pageblock_order value.

Currently, default hugetlbe page size is set via arch_initcalls which happens
late in the boot as shown via the below callstack:

[c000000007383b10] [c000000001289328] hugetlbpage_init+0x2b8/0x2f8
[c000000007383bc0] [c0000000012749e4] do_one_initcall+0x14c/0x320
[c000000007383c90] [c00000000127505c] kernel_init_freeable+0x410/0x4e8
[c000000007383da0] [c000000000012664] kernel_init+0x30/0x15c
[c000000007383e10] [c00000000000cf14] ret_from_kernel_thread+0x5c/0x64

and the pageblock_order initialization is done early during the boot.

[c0000000018bfc80] [c0000000012ae120] set_pageblock_order+0x50/0x64
[c0000000018bfca0] [c0000000012b3d94] sparse_init+0x188/0x268
[c0000000018bfd60] [c000000001288bfc] initmem_init+0x28c/0x328
[c0000000018bfe50] [c00000000127b370] setup_arch+0x410/0x480
[c0000000018bfed0] [c00000000127401c] start_kernel+0xb8/0x934
[c0000000018bff90] [c00000000000d984] start_here_common+0x1c/0x98

delaying default hugetlb page size initialization implies the kernel will
initialize pageblock_order to (MAX_ORDER - 1) which is not an optimal
value for mobility grouping. IIUC we always had this issue. But it was not
a problem for hash translation mode because (MAX_ORDER - 1) is the same as
HUGETLB_PAGE_ORDER (8) in the case of hash (16MB). With radix,
HUGETLB_PAGE_ORDER will be 5 (2M size) and hence pageblock_order should be
5 instead of 8.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220211065215.101767-1-aneesh.kumar@linux.ibm.com

While debugging an issue, we wanted to check whether the arch specific
kernel memmove implementation is correct.
This selftest could help test that.

Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/57242c1fe7aba6b7f0fcd0490303bfd5f222ee00.1631512686.git.riteshh@linux.ibm.com

pseries_devicetree_update() has only one call site, in the same file in
which it is defined. Make it static.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220207221247.354454-1-nathanl@linux.ibm.com

Now that gettimeofday.S is unique, move cvdso_call macro
into that file which is the only user.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/72720359d4c58e3a3b96dd74952741225faac3de.1642782130.git.christophe.leroy@csgroup.eu