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Add two attributes for debug purposes. They can be found under;
/sys/devices/system/cpu/hiperdispatch/
* hd_stime_threshold : allows user to adjust steal time threshold
* hd_delay_factor : allows user to adjust delay factor of hiperdispatch
work (after topology updates, delayed work is
always delayed extra by this factor)
hd_stime_threshold can have values between 0-100 as it represents a
percentage value.
hd_delay_factor can have values greater than 1. It is multiplied with
the default delay to achieve a longer interval, pushing back the next
hiperdispatch adjustment after a topology update.
Ex:
if delay interval is 250ms and the delay factor is 4;
delayed interval is now 1000ms(1sec). After each capacity adjustment
or topology change, work has a delayed interval of 1 sec for one
interval.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Expose hiperdispatch controls via sysctl. The user can now toggle
hiperdispatch via assigning 0 or 1 to s390.hiperdispatch attribute.
When hiperdipatch is toggled on, it tries to adjust CPU capacities,
while system is in vertical polarization to gain performance benefits
from different CPU polarizations. Disabling hiperdispatch reverts the
CPU capacities to their default (HIGH_CAPACITY) and stops the dynamic
adjustments.
Introduce a kconfig option HIPERDISPATCH_ON which allows users to
use hiperdispatch by default on vertical polarization. Using the
sysctl attribute s390.hiperdispatch would overwrite this behavior.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Add trace events to debug hiperdispatch behavior and track domain
rebuilding. Two events provide information about the decision making of
hiperdispatch and the adjustments made.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Co-developed-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The measurements done by hiperdispatch can have sudden spikes and dips
during run time. To prevent these outliers effecting the decision making
process and causing adjustment overhead, use weighted average of the
steal time.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Co-developed-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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When LPAR is in vertical polarization, CPUs get different polarization
values, namely vertical high, vertical medium and vertical low. These
values represent the likelyhood of the CPU getting physical runtime.
Vertical high CPUs will always get runtime and others get varying
runtime depending on the load the CEC is under.
Vertical high and vertical medium CPUs are considered the CPUs which the
current LPAR has the entitlement to run on. The vertical lows are on the
other hand are borrowed CPUs which would only be given to the LPAR by
hipervisor when the other LPARs are not utilizing them.
Using the CPU capacities, hint linux scheduler when it should prioritise
vertical high and vertical medium CPUs over vertical low CPUs.
By tracking various system statistics hiperdispatch determines when to
adjust cpu capacities.
After each adjustment, rebuilding of scheduler domains is necessary to
notify the scheduler about capacity changes but since this operation is
costly it should be done as sparsely as possible.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Co-developed-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Linux scheduler allows architectures to assign capacity values to
individual CPUs. This hints scheduler the performance difference between
CPUs and allows more efficient task distribution them. Implement
helper methods to set and get CPU capacities for s390. This is
particularly helpful in vertical polarization configurations of LPARs.
On vertical polarization an LPARs CPUs can get different polarization
values depending on the CEC configuration. CPUs with different
polarization values can perform different from each other, using CPU
capacities this can be reflected to linux scheduler.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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By default, all systems on s390 start in horizontal cpu polarization.
Selecting the new config option SCHED_TOPOLOGY_VERTICAL allows to build
a kernel that switches to vertical polarization during boot.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Provide an additional path to set the polarization of the system, such
that a user no longer relies on the sysfs interface only and is able
configure the polarization for every reboot via sysctl control files.
The new sysctl can be set as follows:
- s390.polarization=0 for horizontal polarization
- s390.polarization=1 for vertical polarization
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Introduce a new debug file which allows to determine how many warning
track grace periods were missed on each CPU.
The new file can be found as /sys/kernel/debug/s390/wti
It is formatted as:
CPU0 CPU1 [...] CPUx
xyz xyz [...] xyz
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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A virtual CPU that has received a warning-track interrupt may fail to
acknowledge the interrupt within the warning-track grace period.
While this is usually not a problem, it will become necessary to
investigate if there is a large number of such missed warning-track
interrupts. Therefore, it is necessary to track these events.
The information is tracked through the s390 debug facility and can be
found under /sys/kernel/debug/s390dbf/wti/.
The hex_ascii output is formatted as:
<pid> <symbol>
The values pid and current psw are collected when a warning track
interrupt is received. Symbol is either the kernel symbol matching the
collected psw or redacted to <user> when running in user space.
Each line represents the currently executing process when a warning
track interrupt was received which was then not acknowledged within its
grace period.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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When a warning track interrupt is received, the kernel has only a very
limited amount of time to make sure, that the CPU can be yielded as
gracefully as possible before being pre-empted by the hypervisor.
The interrupt handler for the wti therefore unparks a kernel thread
which has being created on boot re-using the CPU hotplug kernel thread
infrastructure. These threads exist per CPU and are assigned the
highest possible real-time priority. This makes sure, that said threads
will execute as soon as possible as the scheduler should pre-empt any
other running user tasks to run the real-time thread.
Furthermore, the interrupt handler disables all I/O interrupts to
prevent additional interrupt processing on the soon-preempted CPU.
Interrupt handlers are likely to take kernel locks, which in the worst
case, will be kept while the interrupt handler is pre-empted from itself
underlying physical CPU. In that case, all tasks or interrupt handlers
on other CPUs would have to wait for the pre-empted CPU being dispatched
again. By preventing further interrupt processing, this risk is
minimized.
Once the CPU gets dispatched again, the real-time kernel thread regains
control, reenables interrupts and parks itself again.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The warning-track interrupt (wti) provides a notification that the
receiving CPU will be pre-empted from its physical CPU within a short
time frame. This time frame is called grace period and depends on the
machine type. Giving up the CPU on time may prevent a task to get stuck
while holding a resource.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The hypfs_dbfs_exit() have been removed since
commit 3325b4d85799 ("s390/hypfs: factor out filesystem code"),
and now it is useless, so remove it.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The only context where ftrace_enable_ftrace_graph_caller()
or ftrace_disable_ftrace_graph_caller() is called also calls
ftrace_arch_code_modify_post_process(), which already performs
text_poke_sync_lock().
ftrace_run_update_code()
arch_ftrace_update_code()
ftrace_modify_all_code()
ftrace_enable_ftrace_graph_caller()/ftrace_disable_ftrace_graph_caller()
ftrace_arch_code_modify_post_process()
text_poke_sync_lock()
Remove the redundant serialization.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Use get/copy_from_kernel_nofault to access the kernel text consistently.
Replace memcmp() in ftrace_init_nop() to ensure that in case of
inconsistencies in the 'mcount' table, the kernel reports a failure
instead of potentially crashing.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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When a sequential instruction fetching facility is present, it is safe
to patch ftrace NOPs in function prologues. All of them are 8-byte
aligned.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Avoid stop machine on kprobes arm/disarm when sequential instruction
fetching is present.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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When sequential instruction fetching facility is present,
certain guarantees are provided for code patching. In particular,
atomic overwrites within 8 aligned bytes is safe from an
instruction-fetching point of view.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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In the past two save areas existed because interrupt handlers
and system call / program check handlers where entered with
interrupts enabled. To prevent a handler from overwriting the
save areas from the previous handler, interrupts used the async
save area, while system call and program check handler used the
sync save area.
Since the removal of critical section cleanup from entry.S, handlers are
entered with interrupts disabled. When the interrupts are re-enabled,
the save area is no longer need. Therefore merge both save areas into one.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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On newer machines the SHA3 performance of CPACF instructions KIMD and
KLMD can be enhanced by using additional modifier bits. This allows the
application to omit initializing the ICV, but also affects the internal
processing of the instructions. Performance is mostly gained when
processing short messages.
The new CPACF feature is backwards compatible with older machines, i.e.
the new modifier bits are ignored on older machines. However, to save the
ICV initialization, the application must detect the MSA level and omit
the ICV initialization only if this feature is supported.
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Joerg Schmidbauer <jschmidb@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Introduce pkey base kernel code with a simple pkey handler registry.
Regroup the pkey code into these kernel modules:
- pkey is the pkey api supporting the ioctls, sysfs and in-kernel api.
Also the pkey base code which offers the handler registry and
handler wrapping invocation functions is integrated there. This
module is automatically loaded in via CPU feature if the MSA feature
is available.
- pkey-cca is the CCA related handler code kernel module a offering
CCA specific implementation for pkey. This module is loaded in
via MODULE_DEVICE_TABLE when a CEX[4-8] card becomes available.
- pkey-ep11 is the EP11 related handler code kernel module offering an
EP11 specific implementation for pkey. This module is loaded in via
MODULE_DEVICE_TABLE when a CEX[4-8] card becomes available.
- pkey-pckmo is the PCKMO related handler code kernel module. This
module is loaded in via CPU feature if the MSA feature is available,
but on init a check for availability of the pckmo instruction is
performed.
The handler modules register via a pkey_handler struct at the pkey
base code and the pkey customer (that is currently the pkey api code
fetches a handler via pkey handler registry functions and calls the
unified handler functions via the pkey base handler functions.
As a result the pkey-cca, pkey-ep11 and pkey-pckmo modules get
independent from each other and it becomes possible to write new
handlers which offer another kind of implementation without implicit
dependencies to other handler implementations and/or kernel device
drivers.
For each of these 4 kernel modules there is an individual Kconfig
entry: CONFIG_PKEY for the base and api, CONFIG_PKEY_CCA for the PKEY
CCA support handler, CONFIG_PKEY_EP11 for the EP11 support handler and
CONFIG_PKEY_PCKMO for the pckmo support. The both CEX related handler
modules (PKEY CCA and PKEY EP11) have a dependency to the zcrypt api
of the zcrypt device driver.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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This is a huge rework of all the pkey kernel module code.
The goal is to split the code into individual parts with
a dedicated calling interface:
- move all the sysfs related code into pkey_sysfs.c
- all the CCA related code goes to pkey_cca.c
- the EP11 stuff has been moved to pkey_ep11.c
- the PCKMO related code is now in pkey_pckmo.c
The CCA, EP11 and PCKMO code may be seen as "handlers" with
a similar calling interface. The new header file pkey_base.h
declares this calling interface. The remaining code in
pkey_api.c handles the ioctl, the pkey module things and the
"handler" independent code on top of the calling interface
invoking the handlers.
This regrouping of the code will be the base for a real
pkey kernel module split into a pkey base module which acts
as a dispatcher and handler modules providing their service.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Add new shash exploiting the HMAC hardware accelerations for SHA224,
SHA256, SHA384 and SHA512 introduced with message-security assist
extension 11.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Add new cipher exploiting the full AES-XTS hardware acceleration
introduced with message-security assist extension 10.
The full AES-XTS cipher is registered as preferred cipher in addition
to the discrete AES-XTS variant.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Remove leftover dentry variable after hypfs refactoring.
Before 2fcb3686e160, hypfs_diag.c and other hypfs files were using
debugfs_create_file() explicitly for creating debugfs files and
were storing the returned pointer.
After the refactor, common debugfs file operations and also the
related dentry pointers have been moved into hypfs_dbfs.c and
redefined as new common mechanisms.
Therefore the dentry variable and the debugfs_remove() function
calls in hypfs_diag.c are now redundant.
Current code is not effected since the dentry pointer in
hypfs_diag is implicitly assigned to NULL and debugfs_remove()
returns without an error if the passed pointer is NULL.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Add more instructions to the kernel disassembler.
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Since commit ba05b39d54ee ("s390/expoline: Make modules use kernel
expolines"), there is no longer any reason not to use
CONFIG_EXPOLINE_EXTERN when supported by the compiler.
On the positive side:
- there is only a single set of expolines generated and used by both the
kernel code and modules,
- it eliminates expolines "comdat" sections, which can confuse tools
like kpatch.
Always enable EXPOLINE_EXTERN if supported by the compiler.
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Over the course of CPU generations a few instructions got extended,
changing their base mnemonic, while keeping the former as an extended
mnemonic. Update the instruction mnemonics in the disassembler to their
latest base mnemonic as documented in the latest IBM z/Architecture
Principles of Operation specification [1].
With the IBM z14 the base mnemonics of the following vector instructions
have been changed:
- Vector FP Load Lengthened (VFLL)
- Vector FP Load Rounded (VFLR)
With Message-Security-Assist Extension 5 Perform Pseudorandom Number
Operation (PPNO) has been renamed to Perform Random Number Operation
(PRNO).
With Vector Enhancements Facility 2 the base mnemonics of the following
vector instructions have been changed:
- Vector FP Convert from Fixed (VCFPS)
- Vector FP Convert from Logical (VCFPL)
- Vector FP Convert to Fixed (VCSFP)
- Vector FP Convert to Logical (VCLFP)
[1] IBM z/Architecture Principles of Operation, SA22-7832-13, IBM z16,
https://publibfp.dhe.ibm.com/epubs/pdf/a227832d.pdf
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Treat register numbers as unsigned. Treat signed operand values as
signed.
This resolves multiple instances of the Cppcheck warning:
warning: %i in format string (no. 1) requires 'int' but the argument
type is 'unsigned int'. [invalidPrintfArgType_sint]
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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ftrace_return_address() is called extremely often from
performance-critical code paths when debugging features like
CONFIG_TRACE_IRQFLAGS are enabled. For example, with debug_defconfig,
ftrace selftests on my LPAR currently execute ftrace_return_address()
as follows:
ftrace_return_address(0) - 0 times (common code uses __builtin_return_address(0) instead)
ftrace_return_address(1) - 2,986,805,401 times (with this patch applied)
ftrace_return_address(2) - 140 times
ftrace_return_address(>2) - 0 times
The use of __builtin_return_address(n) was replaced by return_address()
with an unwinder call by commit cae74ba8c295 ("s390/ftrace:
Use unwinder instead of __builtin_return_address()") because
__builtin_return_address(n) simply walks the stack backchain and doesn't
check for reaching the stack top. For shallow stacks with fewer than
"n" frames, this results in reads at low addresses and random
memory accesses.
While calling the fully functional unwinder "works", it is very slow
for this purpose. Moreover, potentially following stack switches and
walking past IRQ context is simply wrong thing to do for
ftrace_return_address().
Reimplement return_address() to essentially be __builtin_return_address(n)
with checks for reaching the stack top. Since the ftrace_return_address(n)
argument is always a constant, keep the implementation in the header,
allowing both GCC and Clang to unroll the loop and optimize it to the
bare minimum.
Fixes: cae74ba8c295 ("s390/ftrace: Use unwinder instead of __builtin_return_address()")
Cc: stable@vger.kernel.org
Reported-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Since commit 778666df60f0 ("s390: compile relocatable kernel without
-fPIE") the kernel vmlinux ELF file is linked with --emit-relocs to
preserve all relocations, so that all absolute relocations can be
extracted using the 'relocs' tool to adjust them during boot.
Port and adapt Petr Pavlu's x86 commit 9d9173e9ceb6 ("x86/build: Avoid
relocation information in final vmlinux") to s390 to strip all
relocations from the final vmlinux ELF file to optimize its size.
Following is his original commit message with minor adaptions for s390:
The Linux build process on s390 roughly consists of compiling all input
files, statically linking them into a vmlinux ELF file, and then taking
and turning this file into an actual bzImage bootable file.
vmlinux has in this process two main purposes:
1) It is an intermediate build target on the way to produce the final
bootable image.
2) It is a file that is expected to be used by debuggers and standard
ELF tooling to work with the built kernel.
For the second purpose, a vmlinux file is typically collected by various
package build recipes, such as distribution spec files, including the
kernel's own tar-pkg target.
When building the kernel vmlinux contains also relocation information
produced by using the --emit-relocs linker option. This is utilized by
subsequent build steps to create relocs.S and produce a relocatable
image. However, the information is not needed by debuggers and other
standard ELF tooling.
The issue is then that the collected vmlinux file and hence distribution
packages end up unnecessarily large because of this extra data. The
following is a size comparison of vmlinux v6.10 with and without the
relocation information:
| Configuration | With relocs | Stripped relocs |
| defconfig | 696 MB | 320 MB |
| -CONFIG_DEBUG_INFO | 48 MB | 32 MB |
Optimize a resulting vmlinux by adding a postlink step that splits the
relocation information into relocs.S and then strips it from the vmlinux
binary.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Now that both the kernel modules area and the kernel image itself are
located within 4 GB, there is no longer a need to maintain a separate
ftrace_plt trampoline. Use the existing trampoline in the kernel.
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Unused since commit b860b9346e2d ("s390/ftrace: remove dead code").
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:
- Fix KASLR base offset to account for symbol offsets in the vmlinux
ELF file, preventing tool breakages like the drgn debugger
- Fix potential memory corruption of physmem_info during kernel
physical address randomization
- Fix potential memory corruption due to overlap between the relocated
lowcore and identity mapping by correctly reserving lowcore memory
- Fix performance regression and avoid randomizing identity mapping
base by default
- Fix unnecessary delay of AP bus binding complete uevent to prevent
startup lag in KVM guests using AP
* tag 's390-6.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/boot: Fix KASLR base offset off by __START_KERNEL bytes
s390/boot: Avoid possible physmem_info segment corruption
s390/ap: Refine AP bus bindings complete processing
s390/mm: Pin identity mapping base to zero
s390/mm: Prevent lowcore vs identity mapping overlap
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If the early program check handler cannot resolve a program check dump
register contents and a call trace to the console before loading a disabled
wait psw. This makes debugging much easier.
Emit an extra message with early_printk() for cases where regular printk()
via the early console is not yet working so that at least some information
is available.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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__do_early_pgm_check() is a function which is only needed during early
setup code. Mark it __init in order to save a few bytes.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Remove WARN_ON_ONCE statements. These have not triggered in the
past.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Rework debug messages:
- Remove most of the debug_sprintf_event() invocations.
- Do not split string format statements
- Remove colon after function name.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Symbol offsets to the KASLR base do not match symbol address in
the vmlinux image. That is the result of setting the KASLR base
to the beginning of .text section as result of an optimization.
Revert that optimization and allocate virtual memory for the
whole kernel image including __START_KERNEL bytes as per the
linker script. That allows keeping the semantics of the KASLR
base offset in sync with other architectures.
Rename __START_KERNEL to TEXT_OFFSET, since it represents the
offset of the .text section within the kernel image, rather than
a virtual address.
Still skip mapping TEXT_OFFSET bytes to save memory on pgtables
and provoke exceptions in case an attempt to access this area is
made, as no kernel symbol may reside there.
In case CONFIG_KASAN is enabled the location counter might exceed
the value of TEXT_OFFSET, while the decompressor linker script
forcefully resets it to TEXT_OFFSET, which leads to a sections
overlap link failure. Use MAX() expression to avoid that.
Reported-by: Omar Sandoval <osandov@osandov.com>
Closes: https://lore.kernel.org/linux-s390/ZnS8dycxhtXBZVky@telecaster.dhcp.thefacebook.com/
Fixes: 56b1069c40c7 ("s390/boot: Rework deployment of the kernel image")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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When physical memory for the kernel image is allocated it does not
consider extra memory required for offsetting the image start to
match it with the lower 20 bits of KASLR virtual base address. That
might lead to kernel access beyond its memory range.
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Fixes: 693d41f7c938 ("s390/mm: Restore mapping of kernel image using large pages")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The hardware DMA limit might not be power of 2. When RAM range starts
above 0, say 4GB, DMA limit of 30 bits should end at 5GB. A single high
bit can not encode this limit.
Use a plain address for the DMA zone limit instead.
Since the DMA zone can now potentially span beyond 4GB physical limit of
DMA32, make sure to use DMA zone for GFP_DMA32 allocations in that case.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Co-developed-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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qsi() executes the instruction qsi (query sample information)
and stores the result of the query in a sample information block
pointed to by the function argument. The instruction does not
change the condition code register. The return code is always
zero. No need to check for errors. Remove now unreferenced
macros PMC_FAILURE and RS_INIT_FAILURE_QSI.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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sf_disable() returns the condition code of instruction lsctl (load
sampling controls). However the parameter to lsctl() in
sf_disable() is a sample control block containing
all zeroes. This invocation of lsctl() does not fail and returns
always zero even when there is no authorization for sampling
on the machine. In short, sampling can be always turned off.
Ignore the return code of sf_disable() and change the function
return to void.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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SIE instruction performs faster when the virtual address of
SIE block matches the physical one. Pin the identity mapping
base to zero for the benefit of SIE and other instructions
that have similar performance impact. Still, randomize the
base when DEBUG_VM kernel configuration option is enabled.
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The identity mapping position in virtual memory is randomized
together with the kernel mapping. That position can never
overlap with the lowcore even when the lowcore is relocated.
Prevent overlapping with the lowcore to allow independent
positioning of the identity mapping. With the current value
of the alternative lowcore address of 0x70000 the overlap
could happen in case the identity mapping is placed at zero.
This is a prerequisite for uncoupling of randomization base
of kernel image and identity mapping in virtual memory.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The __insn32_query() function incorrectly uses the RRF instruction format
for both the SORTL (RRE format) and DFLTCC (RRF format) instructions.
To fix this issue, add separate query functions for SORTL and DFLTCC that
use the appropriate instruction formats.
Additionally pass the query operand as a pointer to the entire array
of 32 elements to slightly optimize performance and readability.
Fixes: d668139718a9 ("KVM: s390: provide query function for instructions returning 32 byte")
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Hariharan Mari <hari55@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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Refactor the list of constant variables into a macro.
This should make it easier to add more constants in the future.
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Instead of getting estimated free pages from memblock directly, we have
introduced an API, memblock_estimated_nr_free_pages(), which is more
friendly for users.
Just replace it with new API, no functional change.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Mike Rapoport <rppt@kernel.org>
CC: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240808001415.6298-3-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
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Bjorn suggests using pdev->dev.groups for attribute_groups constructed on
PCI device enumeration:
"Is it feasible to build an attribute group in pci_doe_init() and
add it to dev->groups so device_add() will automatically add them?"
https://lore.kernel.org/r/20231019165829.GA1381099@bhelgaas
Unfortunately on s390, pcibios_device_add() usurps pdev->dev.groups for
arch-specific attribute_groups, preventing its use for anything else.
Introduce an ARCH_PCI_DEV_GROUPS macro which arches can define in
<asm/pci.h>. The macro is visible in drivers/pci/pci-sysfs.c through the
inclusion of <linux/pci.h>, which in turn includes <asm/pci.h>.
On s390, define the macro to the three attribute_groups previously assigned
to pdev->dev.groups. Thereby pdev->dev.groups is made available for use by
the PCI core.
As a side effect, arch/s390/pci/pci_sysfs.c no longer needs to be compiled
into the kernel if CONFIG_SYSFS=n.
Link: https://lore.kernel.org/r/7b970f7923e373d1b23784721208f93418720485.1722870934.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
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Save some bytes and move early_pgm_check_handler() to init text
section.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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