With /sys/firmware/opal/core support available on OPAL based machines
and an option to the release memory used by kernel in exporting this
core file, update FADump documentation with these details.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821382786.5656.13173494907671241231.stgit@hbathini.in.ibm.com
OPAL loads kernel & initrd at 512MB offset (256MB size), also exported
as ibm,opal/dump/fw-load-area. So, if boot memory size of FADump is
less than 768MB, kernel memory to be exported as '/proc/vmcore' would
be overwritten by f/w while loading kernel & initrd. To avoid such a
scenario, enforce a minimum boot memory size of 768MB on OPAL platform
and skip using FADump if a newer F/W version loads kernel & initrd
above 768MB.
Also, irrespective of RMA size, set the minimum boot memory size
expected on pseries platform at 320MB. This is to avoid inflating the
minimum memory requirements on systems with 512M/1024M RMA size.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821381414.5656.1592867278535469652.stgit@hbathini.in.ibm.com
Export /sys/firmware/opal/core file to analyze opal crashes. Since OPAL
core can be generated independent of CONFIG_FA_DUMP support in kernel,
add this support under a new kernel config option CONFIG_OPAL_CORE.
Also, avoid code duplication by moving common code used while exporting
/proc/vmcore and/or /sys/firmware/opal/core file(s).
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821378503.5656.3693769384945087756.stgit@hbathini.in.ibm.com
Kernel config option CONFIG_PRESERVE_FA_DUMP is introduced to ensure
crash data, from previously crash'ed kernel, is preserved. Update
documentation with this details.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821377195.5656.15840065629705958324.stgit@hbathini.in.ibm.com
Add a new kernel config option, CONFIG_PRESERVE_FA_DUMP that ensures
that crash data, from previously crash'ed kernel, is preserved. This
helps in cases where FADump is not enabled but the subsequent memory
preserving kernel boot is likely to process this crash data. One
typical usecase for this config option is petitboot kernel.
As OPAL allows registering address with it in the first kernel and
retrieving it after MPIPL, use it to store the top of boot memory.
A kernel that intends to preserve crash data retrieves it and avoids
using memory beyond this address.
Move arch_reserved_kernel_pages() function as it is needed for both
FA_DUMP and PRESERVE_FA_DUMP configurations.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821375751.5656.11459483669542541602.stgit@hbathini.in.ibm.com
The size parameter to fadump_reserve_crash_area() function is not needed
as all the memory above boot memory size must be preserved anyway. Update
the function by dropping this redundant parameter.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821374440.5656.2945512543806951766.stgit@hbathini.in.ibm.com
Commit 0962e8004e ("powerpc/prom: Scan reserved-ranges node for
memory reservations") enabled support to parse 'reserved-ranges' DT
node to reserve kernel memory falling in these ranges for firmware
purposes. Along with the preserved area memory, ensure memory in
reserved ranges is not overlapped with memory released by capture
kernel aftering saving vmcore. Also, fix the off-by-one error in
fadump_release_reserved_area function while releasing memory.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821371358.5656.6061214942558818661.stgit@hbathini.in.ibm.com
Make allocate_crash_memory_ranges() and free_crash_memory_ranges()
functions generic to reuse them for memory management of all types of
dynamic memory range arrays. This change helps in memory management
of reserved ranges array to be added later.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821369863.5656.4375667005352155892.stgit@hbathini.in.ibm.com
Firmware provides architected register state data at the time of crash.
Process this data and build CPU notes to append to ELF core. In case
this data is missing or in unsupported format, at least append crashing
CPU's register data, to have something to work with in the vmcore file.
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821367702.5656.5546683836236508389.stgit@hbathini.in.ibm.com
Earlier, memblock_find_in_range() was not used to find the memory to
be reserved for FADump as bottom up allocation mode was not supported.
But since commit 79442ed189 ("mm/memblock.c: introduce bottom-up
allocation mode") bottom up allocation mode is supported for memblock.
So, use it to find the memory to be reserved for FADump.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821364211.5656.14336025460336135194.stgit@hbathini.in.ibm.com
Make OPAL call to indicate that the dump is processed and the metadata
area in OPAL can be cleared/released. Also, setup/initialize FADump
for re-registration.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821356046.5656.12270927048195494911.stgit@hbathini.in.ibm.com
If all kernel boot memory regions are not registered for MPIPL before
system crashes, try processing the partial crashdump but warn the user
before proceeding.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821352793.5656.1734051341024721407.stgit@hbathini.in.ibm.com
Add support in the kernel to process the crash'ed kernel's memory
preserved during MPIPL and export it as /proc/vmcore file for the
userland scripts to filter and analyze it later.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821351482.5656.6255805804744333073.stgit@hbathini.in.ibm.com
Firmware uses a 32-bit field for size while copying/backing-up memory
during MPIPL. So, the maximum value that could be represented with
a PAGE_SIZE aligned 32-bit field will be the maximum copy size for a
region but FADump capture kernel usually needs more memory than that
to be preserved to avoid running into out of memory errors.
So, request firmware to copy multiple kernel boot memory regions
instead of just one (which worked fine for pseries as 64-bit field
was used for size there).
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821350193.5656.3664853158523582019.stgit@hbathini.in.ibm.com
During kexec boot, metadata address needs to be reset to avoid running
into errors interpreting stale metadata address, in case the kexec'ed
kernel crashes before metadata address could be setup again.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821346629.5656.10783321582005237813.stgit@hbathini.in.ibm.com
OPAL allows registering address with it in the first kernel and
retrieving it after MPIPL. Setup kernel metadata and register its
address with OPAL to use it for processing the crash dump.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821345011.5656.13567765019032928471.stgit@hbathini.in.ibm.com
MPIPL is Memory Preserving IPL supported from POWER9. This enables the
kernel to reset the system with memory 'preserved'. Also, it supports
copying memory from a source address to some destination address during
MPIPL boot. Add MPIPL interface definitions here to leverage these f/w
features in adding FADump support for PowerNV platform.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821340710.5656.10071829040515662624.stgit@hbathini.in.ibm.com
Except for Reserved dump area (see Documentation/powerpc/firmware-
assisted-dump.rst) which is permanent reserved, all memory above boot
memory size, where boot memory size is the memory required for the
kernel to boot successfully when booted with restricted memory (memory
for capture kernel), is released when the dump is invalidated. Make
this a bit more explicit in the code.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821336092.5656.1079046285366041687.stgit@hbathini.in.ibm.com
Move platform specific register/un-register code, the RTAS calls, to
register/un-register callback functions. This would also mean moving
code that initializes and prints the platform specific FADump data.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821332856.5656.16380417702046411631.stgit@hbathini.in.ibm.com
Introduce callback functions for platform specific operations like
register, unregister, invalidate & such. Also, define place-holders
for the same on pSeries platform.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821330286.5656.15538934400074110770.stgit@hbathini.in.ibm.com
Currently, FADump is only supported on pSeries but that is going to
change soon with FADump support being added on PowerNV platform. So,
move rtas specific definitions to platform code to allow FADump
to have multiple platforms support.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821328494.5656.16219929140866195511.stgit@hbathini.in.ibm.com
The figures depicting FADump's (Firmware-Assisted Dump) memory layout
are missing some finer details like different memory regions and what
they represent. Improve the documentation by updating those details.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821322070.5656.8194734198500730487.stgit@hbathini.in.ibm.com
Add helper functions to setup & free CPU notes buffer and to find if a
given memory area is contiguous. Also, use boolean as return type for
the function that finds if boot memory area is contiguous. While at
it, save the virtual address of CPU notes buffer instead of physical
address as virtual address is used often.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821318971.5656.9281936950510635858.stgit@hbathini.in.ibm.com
Though asm/fadump.h is meant to be used by other components dealing
with FADump, it also has macros/definitions internal to FADump code.
Move them to a new header file used within FADump code. This also
makes way for refactoring platform specific FADump code.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821313134.5656.6597770626574392140.stgit@hbathini.in.ibm.com
This slightly improves the prom_init_check rule.
[1] Avoid needless check
Currently, prom_init_check.sh is invoked every time you run 'make'
even if you have changed nothing in prom_init.c. With this commit,
the script is re-run only when prom_init.o is recompiled.
[2] Beautify the build log
Currently, the O= build shows the absolute path to the script:
CALL /abs/path/to/source/of/linux/arch/powerpc/kernel/prom_init_check.sh
With this commit, it is always a relative path to the timestamp file:
PROMCHK arch/powerpc/kernel/prom_init_check
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912074037.13813-1-yamada.masahiro@socionext.com
Some of the templates used for KVM patching are only used on certain
platforms, but currently they are always built-in, fix that.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911115746.12433-4-mpe@ellerman.id.au
All the code in kvm.c can be marked __init. Most of it is already
inlined into the initcall, but not all. So instead of relying on the
inlining, mark it all as __init. This saves ~280 bytes of text for my
configuration.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911115746.12433-3-mpe@ellerman.id.au
In some configurations of KVM, guests binary patch themselves to
avoid/reduce trapping into the hypervisor. For some instructions this
requires replacing one instruction with a sequence of instructions.
For those cases we need to write the sequence of instructions
somewhere and then patch the location of the original instruction to
branch to the sequence. That requires that the location of the
sequence be within 32MB of the original instruction.
The current solution for this is that we create a 1MB array in BSS,
write sequences into there, and then free the remainder of the array.
This has a few problems:
- it confuses kmemleak.
- it confuses lockdep.
- it requires mapping kvm_tmp executable, which can cause adjacent
areas to also be mapped executable if we're using 16M pages for the
linear mapping.
- the 32MB limit can be exceeded if the kernel is big enough,
especially with STRICT_KERNEL_RWX enabled, which then prevents the
patching from working at all.
We can fix all those problems by making kvm_tmp just a region of
regular .text. However currently it's 1MB in size, and we don't want
to waste 1MB of text. In practice however I only see ~30KB of kvm_tmp
being used even for an allyes_config. So shrink kvm_tmp to 64K, which
ought to be enough for everyone, and move it into .text.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911115746.12433-1-mpe@ellerman.id.au
The builds breaks when IOMMU_API=n, eg. skiroot_defconfig:
arch/powerpc/platforms/powernv/npu-dma.c:96:28: error: 'get_gpu_pci_dev_and_pe' defined but not used
arch/powerpc/platforms/powernv/npu-dma.c:126:13: error: 'pnv_npu_set_window' defined but not used
Fixes: b4d37a7b69 ("powerpc/powernv: Remove unused pnv_npu_try_dma_set_bypass() function")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The build breaks when STACKTRACE=n, eg. skiroot_defconfig:
arch/powerpc/kernel/eeh_event.c:124:23: error: implicit declaration of function 'stack_trace_save'
Fix it with some ifdefs for now.
Fixes: 25baf3d816 ("powerpc/eeh: Defer printing stack trace")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There's a bug in skiboot that causes the OPAL_XIVE_ALLOCATE_IRQ call
to return the 32-bit value 0xffffffff when OPAL has run out of IRQs.
Unfortunatelty, OPAL return values are signed 64-bit entities and
errors are supposed to be negative. If that happens, the linux code
confusingly treats 0xffffffff as a valid IRQ number and panics at some
point.
A fix was recently merged in skiboot:
e97391ae2bb5 ("xive: fix return value of opal_xive_allocate_irq()")
but we need a workaround anyway to support older skiboots already
in the field.
Internally convert 0xffffffff to OPAL_RESOURCE which is the usual error
returned upon resource exhaustion.
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821713818.1985334.14123187368108582810.stgit@bahia.lan
prep_irq_for_idle() is intended to be called before entering
H_CEDE (and it is used by the pseries cpuidle driver). However the
default pseries idle routine does not call it, leading to mismanaged
lazy irq state when the cpuidle driver isn't in use. Manifestations of
this include:
* Dropped IPIs in the time immediately after a cpu comes
online (before it has installed the cpuidle handler), making the
online operation block indefinitely waiting for the new cpu to
respond.
* Hitting this WARN_ON in arch_local_irq_restore():
/*
* We should already be hard disabled here. We had bugs
* where that wasn't the case so let's dbl check it and
* warn if we are wrong. Only do that when IRQ tracing
* is enabled as mfmsr() can be costly.
*/
if (WARN_ON_ONCE(mfmsr() & MSR_EE))
__hard_irq_disable();
Call prep_irq_for_idle() from pseries_lpar_idle() and honor its
result.
Fixes: 363edbe261 ("powerpc: Default arch idle could cede processor on pseries")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190910225244.25056-1-nathanl@linux.ibm.com
If watchpoint exception is generated by larx/stcx instructions, the
reservation created by larx gets lost while handling exception, and
thus stcx instruction always fails. Generally these instructions are
used in a while(1) loop, for example spinlocks. And because stcx
never succeeds, it loops forever and ultimately hangs the system.
Note that ptrace anyway works in one-shot mode and thus for ptrace
we don't change the behaviour. It's up to ptrace user to take care
of this.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Acked-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/20190910131513.30499-1-ravi.bangoria@linux.ibm.com
We have OPAL_MSG_PRD message type to pass prd related messages from
OPAL to `opal-prd`. It can handle messages upto 64 bytes. We have a
requirement to send bigger than 64 bytes of data from OPAL to
`opal-prd`. Lets add new message type (OPAL_MSG_PRD2) to pass bigger
data.
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Make the error string clear that it's the PRD2 event that failed]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190826065701.8853-2-hegdevasant@linux.vnet.ibm.com
Use "opal-msg-size" device tree property to allocate memory for
"opal_msg".
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: s/uint32_t/u32/ and mark opal_msg_size as __ro_after_init]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190826065701.8853-1-hegdevasant@linux.vnet.ibm.com
Neither pnv_npu_try_dma_set_bypass() nor the pnv_npu_dma_set_32() and
pnv_npu_dma_set_bypass() helpers called by it are used anywhere in the
kernel tree, so remove them.
mpe: They're unused since 2d6ad41b2c ("powerpc/powernv: use the
generic iommu bypass code") removed the last usage.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903165147.11099-1-hch@lst.de
For sizes lesser than 128 bytes, the code branches out early without saving
the stack frame, which when restored later drops frame of the caller.
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903214359.23887-1-santosh@fossix.org
Hari Bathini