Alexey Gladkov says:
The modules.builtin.modinfo file is used by userspace (kmod to be specific) to
get information about builtin modules. Among other information about the module,
information about module aliases is stored. This is very important to determine
that a particular modalias will be handled by a module that is inside the
kernel.
There are several mechanisms for creating modalias for modules:
The first is to explicitly specify the MODULE_ALIAS of the macro. In this case,
the aliases go into the '.modinfo' section of the module if it is compiled
separately or into vmlinux.o if it is builtin into the kernel.
The second is the use of MODULE_DEVICE_TABLE followed by the use of the
modpost utility. In this case, vmlinux.o no longer has this information and
does not get it into modules.builtin.modinfo.
For example:
$ modinfo pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30
modinfo: ERROR: Module pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30 not found.
$ modinfo xhci_pci
name: xhci_pci
filename: (builtin)
license: GPL
file: drivers/usb/host/xhci-pci
description: xHCI PCI Host Controller Driver
The builtin module is missing alias "pci:v*d*sv*sd*bc0Csc03i30*" which will be
generated by modpost if the module is built separately.
To fix this it is necessary to add the generated by modpost modalias to
modules.builtin.modinfo. Fortunately modpost already generates .vmlinux.export.c
for exported symbols. It is possible to add `.modinfo` for builtin modules and
modify the build system so that `.modinfo` section is extracted from the
intermediate vmlinux after modpost is executed.
Link: https://patch.msgid.link/cover.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Since .vmlinux.export.c is used to add generated by modpost modaliases
for builtin modules the .vmlinux.export.o is no longer optional and
should always be created. The generation of this file is not dependent
on CONFIG_MODULES.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/0e63a9c7741fe8217e4fd7c60afcf057ffa2ef5a.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
For some modules, modalias is generated using the modpost utility and
the section is added to the module file.
When a module is added inside vmlinux, modpost does not generate
modalias for such modules and the information is lost.
As a result kmod (which uses modules.builtin.modinfo in userspace)
cannot determine that modalias is handled by a builtin kernel module.
$ cat /sys/devices/pci0000:00/0000:00:14.0/modalias
pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30
$ modinfo xhci_pci
name: xhci_pci
filename: (builtin)
license: GPL
file: drivers/usb/host/xhci-pci
description: xHCI PCI Host Controller Driver
Missing modalias "pci:v*d*sv*sd*bc0Csc03i30*" which will be generated by
modpost if the module is built separately.
To fix this it is necessary to generate the same modalias for vmlinux as
for the individual modules. Fortunately '.vmlinux.export.o' is already
generated from which '.modinfo' can be extracted in the same way as for
vmlinux.o.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/28d4da3b0e3fc8474142746bcf469e03752c3208.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
At this point, if a symbol is compiled as part of the kernel,
information about which module the symbol belongs to is lost.
To save this it is possible to add the module name to the alias name.
It's not very pretty, but it's possible for now.
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: rust-for-linux@vger.kernel.org
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/1a0d0bd87a4981d465b9ed21e14f4e78eaa03ded.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
The blogic_pci_tbl structure is used by the MODULE_DEVICE_TABLE macro.
There is no longer a need to protect it with the MODULE condition, since
this no longer causes the compiler to warn about an unused variable.
To avoid warnings when -Wunused-const-variable option is used, mark it
as __maybe_unused for such configuration.
Cc: Khalid Aziz <khalid@gonehiking.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://patch.msgid.link/fd8e30de07de79a4923ae967eaee5ba2f2fcef00.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Currently, we assume all the data for modules.builtin.modinfo are
available in vmlinux.o.
This makes it impossible for modpost, which is invoked after vmlinux.o,
to add additional module info.
This commit moves the modules.builtin.modinfo rule after modpost.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/cdb3e5b9a739666b755cd0097dc34ab69c350e51.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Keep the .modinfo section during linking, but strip it from the final
vmlinux.
Adjust scripts/mksysmap to exclude modinfo symbols from kallsyms.
This change will allow the next commit to extract the .modinfo section
from the vmlinux.unstripped intermediate.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/aaf67c07447215463300fccaa758904bac42f992.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Generate the intermediate vmlinux.unstripped regardless of
CONFIG_ARCH_VMLINUX_NEEDS_RELOCS.
If CONFIG_ARCH_VMLINUX_NEEDS_RELOCS is unset, vmlinux.unstripped and
vmlinux are identiacal.
This simplifies the build rule, and allows to strip more sections
by adding them to remove-section-y.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/a48ca543fa2305bd17324f41606dcaed9b19f2d4.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
In the upcoming changes, the ELF_DETAILS macro will be extended with
the ".modinfo" section, which will cause an error:
>> s390x-linux-ld: .tmp_vmlinux1: warning: allocated section `.modinfo' not in segment
>> s390x-linux-ld: .tmp_vmlinux2: warning: allocated section `.modinfo' not in segment
>> s390x-linux-ld: vmlinux.unstripped: warning: allocated section `.modinfo' not in segment
This happens because the .vmlinux.info use :NONE to override the default
segment and tell the linker to not put the section in any segment at all.
To avoid this, we need to change the sections order that will be placed
in the default segment.
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506062053.zbkFBEnJ-lkp@intel.com/
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://patch.msgid.link/20d40a7a3a053ba06a54155e777dcde7fdada1db.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
The kexec code will call set_pages_state() after tearing down all the GHCBs,
which will therefore result in a call to early_set_pages_state().
This means the __init annotation is wrong, and must be dropped.
Fixes: c5c30a3736 ("x86/boot: Move startup code out of __head section")
Reported-by: Srikanth Aithal <Srikanth.Aithal@amd.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Srikanth Aithal <Srikanth.Aithal@amd.com>
./arch/arm64/kernel/cpufeature.c: asm/mmu.h is included more than once.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>
* for-next/selftests:
kselftest/arm64: Add lsfe to the hwcaps test
kselftest/arm64: Check that unsupported regsets fail in sve-ptrace
kselftest/arm64: Verify that we reject out of bounds VLs in sve-ptrace
kselftest/arm64/gcs/basic-gcs: Respect parent directory CFLAGS
selftests/arm64: Fix grammatical error in string literals
kselftest/arm64: Add parentheses around sizeof for clarity
kselftest/arm64: Supress warning and improve readability
kselftest/arm64: Remove extra blank line
kselftest/arm64/gcs: Use nolibc's getauxval()
kselftest/arm64/gcs: Correctly check return value when disabling GCS
selftests: arm64: Fix -Waddress warning in tpidr2 test
kselftest/arm64: Log error codes in sve-ptrace
selftests: arm64: Check fread return value in exec_target
* for-next/perf: (29 commits)
perf/dwc_pcie: Fix use of uninitialized variable
Documentation: hisi-pmu: Add introduction to HiSilicon V3 PMU
Documentation: hisi-pmu: Fix of minor format error
drivers/perf: hisi: Add support for L3C PMU v3
drivers/perf: hisi: Refactor the event configuration of L3C PMU
drivers/perf: hisi: Extend the field of tt_core
drivers/perf: hisi: Extract the event filter check of L3C PMU
drivers/perf: hisi: Simplify the probe process of each L3C PMU version
drivers/perf: hisi: Export hisi_uncore_pmu_isr()
drivers/perf: hisi: Relax the event ID check in the framework
perf: Fujitsu: Add the Uncore PMU driver
perf/arm-cmn: Fix CMN S3 DTM offset
perf: arm_spe: Prevent overflow in PERF_IDX2OFF()
coresight: trbe: Prevent overflow in PERF_IDX2OFF()
MAINTAINERS: Remove myself from HiSilicon PMU maintainers
drivers/perf: hisi: Add support for HiSilicon MN PMU driver
drivers/perf: hisi: Add support for HiSilicon NoC PMU
perf: arm_pmuv3: Factor out PMCCNTR_EL0 use conditions
arm64/boot: Enable EL2 requirements for SPE_FEAT_FDS
arm64/boot: Factor out a macro to check SPE version
...
* for-next/misc:
arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN
arm64: Kconfig: Spell out "ARMv9.4" in menuconfig text
arm64/fpsimd: simplify sme_setup()
* for-next/entry:
arm/syscalls: mark syscall invocation as likely in invoke_syscall
arm64: entry: Switch to generic IRQ entry
arm64: entry: Move arm64_preempt_schedule_irq() into __exit_to_kernel_mode()
arm64: entry: Refactor preempt_schedule_irq() check code
entry: Add arch_irqentry_exit_need_resched() for arm64
arm64: entry: Use preempt_count() and need_resched() helper
arm64: entry: Rework arm64_preempt_schedule_irq()
arm64: entry: Refactor the entry and exit for exceptions from EL1
arm64: ptrace: Replace interrupts_enabled() with regs_irqs_disabled()
* for-next/fixes:
arm64: ftrace: fix unreachable PLT for ftrace_caller in init_module with CONFIG_DYNAMIC_FTRACE
ACPI/IORT: Fix memory leak in iort_rmr_alloc_sids()
arm64: uapi: Provide correct __BITS_PER_LONG for the compat vDSO
kselftest/arm64: Don't open code SVE_PT_SIZE() in fp-ptrace
arm64: mm: Fix CFI failure due to kpti_ng_pgd_alloc function signature
Big-endian arm64 configurations are vanishingly rare, yet we still claim
to support them in Linux despite very limited testing or visible
interest. Supporting big-endian adds unnecessary burden to reviewers and
contributors which, without any known active users, is hard to justify.
For example, recent work to improve our futex routines and to implement
nested virtualisation support is non-trivially complicated by having to
support both big- and little-endianness.
Back in 2019 [1], it was claimed that Huawei were using arm64 big-endian
machines in their telecommunication products but I don't know whether
that's still the case and certainly haven't seen any patch contributions
to help support or maintain it.
Make CPU_BIG_ENDIAN depend on BROKEN as an initial deprecation step
towards its removal.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/linux-arm-kernel/73701e9f-bee1-7ae8-2277-7a3576171cd4@huawei.com/ [1]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Vincent Mailhol <mailhol@kernel.org> says:
In November last year, I sent an RFC to introduce CAN XL [1]. That
RFC, despite positive feedback, was put on hold due to some unanswered
question concerning the PWM encoding [2].
While stuck, some small preparation work was done in parallel in [3]
by refactoring the struct can_priv and doing some trivial clean-up and
renaming. Initially, [3] received zero feedback but was eventually
merged after splitting it in smaller parts and resending it.
Finally, in July this year, we clarified the remaining mysteries about
PWM calculation, thus unlocking the series. Summer being a bit busy
because of some personal matters brings us to now.
After doing all the refactoring and adding all the CAN XL features,
the final result is more than 30 patches, definitively too much for a
single series. So I am splitting the remaining changes three:
- can: rework the CAN MTU logic [4]
- can: netlink: preparation before introduction of CAN XL (this series)
- CAN XL (will come right after the two preparation series get merged)
And thus, this series continues and finishes the preparation work done
in [3] and [4]. It contains all the refactoring needed to smoothly
introduce CAN XL. The goal is to:
- split the functions in smaller pieces: CAN XL will introduce a
fair amount of code. And some functions which are already fairly
long (86 lines for can_validate(), 215 lines for can_changelink())
would grow to disproportionate sizes if the CAN XL logic were to
be inlined in those functions.
- repurpose the existing code to handle both CAN FD and CAN XL: a
huge part of CAN XL simply reuses the CAN FD logic. All the
existing CAN FD logic is made more generic to handle both CAN FD
and XL.
In more details:
- Patch #1 moves struct data_bittiming_params from dev.h to
bittiming.h and patch #2 makes can_get_relative_tdco() FD agnostic
before also moving it to bittiming.h.
- Patch #3 adds some comments to netlink.h tagging which IFLA
symbols are FD specific.
- Patches #4 to #6 are refactoring can_validate() and
can_validate_bittiming().
- Patches #7 to #11 are refactoring can_changelink() and
can_tdc_changelink().
- Patches #12 and #13 are refactoring can_get_size() and
can_tdc_get_size().
- Patches #14 to #17 are refactoring can_fill_info() and
can_tdc_fill_info().
- Patch #18 makes can_calc_tdco() FD agnostic.
- Patch #19 adds can_get_ctrlmode_str() which converts control mode
flags into strings. This is done in preparation of patch #20.
- Patch #20 is the final patch and improves the user experience by
providing detailed error messages whenever invalid parameters are
provided. All those error messages came into handy when debugging
the upcoming CAN XL patches.
Aside from the last patch, the other changes do not impact any of the
existing functionalities.
The follow up series which introduces CAN XL is nearly completed but
will be sent only once this one is approved: one thing at a time, I do
not want to overwhelm people (including myself).
[1] https://lore.kernel.org/linux-can/20241110155902.72807-16-mailhol.vincent@wanadoo.fr/
[2] https://lore.kernel.org/linux-can/c4771c16-c578-4a6d-baee-918fe276dbe9@wanadoo.fr/
[3] https://lore.kernel.org/linux-can/20241110155902.72807-16-mailhol.vincent@wanadoo.fr/
[4] https://lore.kernel.org/linux-can/20250923-can-fix-mtu-v2-0-984f9868db69@kernel.org/
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-0-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Use NL_SET_ERR_MSG() and NL_SET_ERR_MSG_FMT() to return meaningful
error messages to the userland whenever a -EOPNOTSUPP error is
returned due to a failed validation of the CAN netlink arguments.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-20-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In an effort to give more human readable messages when errors occur
because of conflicting options, it can be useful to convert the CAN
control mode flags into text.
Add a function which converts the first set CAN control mode into a
human readable string. The reason to only convert the first one is to
simplify edge cases: imagine that there are several invalid control
modes, we would just return the first invalid one to the user, thus
not having to handle complex string concatenation. The user can then
solve the first problem, call the netlink interface again and see the
next issue.
People who wish to enumerate all the control modes can still do so by,
for example, using this new function in a for_each_set_bit() loop.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-19-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
can_calc_tdco() uses the CAN_CTRLMODE_FD_TDC_MASK and
CAN_CTRLMODE_TDC_AUTO macros making it specific to CAN FD. Add the tdc
mask to the function parameter list. The value of the tdc auto flag
can then be derived from that mask and stored in a local variable.
This way, the function becomes CAN FD agnostic and can be reused later
on for the CAN XL TDC.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-18-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
can_tdc_fill_info() depends on some variables which are specific to CAN
FD. Move these to the function parameters list so that, later on, this
function can be reused for the CAN XL TDC.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-17-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add can_bitrate_const_fill_info() to factorise the logic when filling
the bitrate constant information for Classical CAN and CAN FD. This
function will be reused later on for CAN XL.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-16-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add function can_bittiming_const_fill_info() to factorise the logic
when filling the bittiming constant information for Classical CAN and
CAN FD. This function will be reused later on for CAN XL.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-15-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add can_bittiming_fill_info() to factorise the logic when filling the
bittiming information for Classical CAN and CAN FD. This function will
be reused later on for CAN XL.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-14-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add the can_data_bittiming_get_size() function to factorise the logic
to retrieve the size of below data bittiming parameters:
- data_bittiming
- data_bittiming_const
- data_bitrate_const
- tdc parameters
This function will be reused later on for CAN XL.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-13-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
can_tdc_get_size() needs to access can_priv->fd making it specific to
CAN FD. Change the function parameter from struct can_priv to struct
data_bittiming_params.
can_tdc_get_size() also uses the CAN_CTRLMODE_TDC_MANUAL macro making
it specific to CAN FD. Add the tdc mask to the function parameter
list. The value of the tdc manual flag can then be derived from that
mask and stored in a local variable.
This way, the function becomes CAN FD agnostic and can be reused later
on for the CAN XL TDC.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-12-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Split the control mode change link logic into a new function:
can_ctrlmode_changelink(). The purpose is to increase code readability
by preventing can_changelink() from becoming too big.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-11-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Factorise the databittiming parsing out of can_changelink() and move
it in the new can_dtb_changelink() function. This is a preparation
patch for the introduction of CAN XL because the databittiming
changelink logic will be reused later on.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-10-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
can_tdc_changelink() needs to access can_priv->fd making it
specific to CAN FD. Change the function parameter from struct can_priv
to struct data_bittiming_params. This way, the function becomes CAN FD
agnostic and can be reused later on for the CAN XL TDC.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-9-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
can_tdc_changelink() return -EOPNOTSUPP under this condition:
!tdc_const || !can_fd_tdc_is_enabled(priv)
But this function is only called if the data[IFLA_CAN_TDC] parameters
are provided. At this point, can_validate_tdc() already checked that
either of the tdc auto or tdc manual control modes were provided, that
is to say, can_fd_tdc_is_enabled(priv) must be true.
Because the right hand operand of this condition is always true,
remove it.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-8-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
CAN_CTRLMODE_TDC_AUTO and CAN_CTRLMODE_TDC_MANUAL are mutually
exclusive. This means that whenever the user switches from auto to
manual mode (or vice versa), the other flag which was set previously
needs to be cleared.
Currently, this is handled with a masking operation. It can be done in
a simpler manner by clearing any of the previous TDC flags before
copying netlink attributes. The code becomes easier to understand and
will make it easier to add the new upcoming CAN XL flags which will
have a similar reset logic as the current TDC flags.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-7-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Factorise the databittiming validation out of can_validate() and move
it in the new add can_validate_databittiming() function. Also move
can_validate()'s comment because it is specific to CAN FD. This is a
preparation patch for the introduction of CAN XL as this databittiming
validation will be reused later on.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-6-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Factorise the TDC validation out of can_validate() and move it in the
new can_validate_tdc() function. This is a preparation patch for the
introduction of CAN XL because this TDC validation will be reused
later on.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-5-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Whenever can_validate_bittiming() is called, it is always preceded by
some boilerplate code which was copy pasted all over the place. Move
that repeated code directly inside can_validate_bittiming().
Finally, the mempcy() is not needed: the nla attributes are four bytes
aligned which is just enough for struct can_bittiming. Add a
static_assert() to document that the alignment is correct and just use
the pointer returned by nla_data() as-is.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-4-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The CAN XL netlink interface will also have data bitrate and TDC
parameters. The current FD parameters do not have a prefix in their
names to differentiate them.
Because the netlink interface is part of the UAPI, it is unfortunately
not feasible to rename the existing symbols to add an FD_ prefix. The
best alternative is to add a comment for each of the symbols to notify
the reader of which parts are CAN FD specific.
While at it, fix a typo: transiver -> transceiver.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-3-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
can_get_relative_tdco() needs to access can_priv->fd making it
specific to CAN FD. Change the function parameter from struct can_priv
to struct data_bittiming_params. This way, the function becomes CAN FD
agnostic and can be reused later on for the CAN XL TDC.
Now that we dropped the dependency on struct can_priv, also move
can_get_relative_tdco() back to bittiming.h where it was meant to
belong to.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-2-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In commit b803c4a4f7 ("can: dev: add struct data_bittiming_params to
group FD parameters"), struct data_bittiming_params was put into
linux/can/dev.h.
This structure being a collection of bittiming parameters, on second
thought, bittiming.h is actually a better location. This way, users of
struct data_bittiming_params will not have to forcefully include
linux/can/dev.h thus removing some complexity and reducing the risk of
circular dependencies in headers.
Move struct data_bittiming_params from linux/can/dev.h to
linux/can/bittiming.h.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-1-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Vincent Mailhol <mailhol@kernel.org> says:
The CAN MTU logic is currently broken. can_change_mtu() will update
both the MTU and the CAN_CTRLMODE_FD flag.
Back then, commit bc05a8944a ("can: allow to change the device mtu
for CAN FD capable devices") stated that:
The configuration can be done either with the 'fd { on | off }'
option in the 'ip' tool from iproute2 or by setting the CAN
netdevice MTU to CAN_MTU (16) or to CANFD_MTU (72).
Link: https://git.kernel.org/torvalds/c/bc05a8944a34
The problem is that after doing for example:
$ ip link set can0 mtu 72 bittiming 500000
on a CAN FD interface, we are left with a device on which CAN FD is
enabled but which does not have the FD databittiming parameters
configured.
The same goes on when setting the mtu back to 16:
ip link set can0 type can bitrate 500000 fd on dbitrate 5000000
ip link set can0 mtu 16
The device is now in Classical CAN mode but iproute2 is still
reporting the databittiming values (although this time, the issue
seems less critical as it is only a reporting problem).
The only way to resolve the problem and bring the device back to a
coherent state is to call again the netlink interface using the
"fd on" or "fd off" options.
The idea of being able to infer the CAN_CTRLMODE_FD flag from the MTU
value is just incorrect for physical devices. Note that this logic
remains valid on virtual interfaces (vcan and vxcan) because those do
not have control mode flags and thus no conflict occurs.
This series reworks the CAN MTU logic. The goal is to always maintain
a coherent state between the MTU and the control mode flags as listed
in below table:
fd off, xl off fd on, xl off fd any, xl on
---------------------------------------------------------------------------
default mtu CAN_MTU CANFD_MTU CANXL_MTU
min mtu CAN_MTU CANFD_MTU CANXL_MIN_MTU
max mtu CAN_MTU CANFD_MTU CANXL_MAX_MTU
In order to switch between one column to another, the user must use
the fd/xl on/off flags. Directly modifying the MTU from one column to
the other is not permitted any more.
The CAN XL is not yet supported at the moment, so the last column is
just given as a reference to better understand what is coming up. This
series will just implement the first two columns.
While doing the rewrite, the logic is adjusted to reuse as much as
possible the net core infrastructure. By populating:
net_device->min_mtu
and
net_device->max_mtu
the net core infrastructure will automatically:
1. validate that the user's inputs are in range.
2. report those min and max MTU values through the netlink
interface.
Point 1. will allow us to get rid of the can_change_mtu() in a near
future for all the physical devices and point 2. allows the end user
to see the valid MTU range by doing a:
$ ip --details link show can0
Finally, because using the net core, it will be possible after the
removal of can_change_mtu() to modify the MTU while the device is up.
As stated previously, the only modifications allowed will be within
the MTU range of a given CAN protocol. So for Classical CAN and CAN
FD, the MTU is fixed to, respectively, CAN_MTU and CANFD_MTU. For the
upcoming CAN XL, the user will be able to change the MTU to anything
between CANXL_MIN_MTU and CANXL_MAX_MTU even if the device is up.
The first patch of this series annotates the read access on
net_device->mtu. This preparation is needed to prevent any race
condition to occur when modifying the MTU while the device is up.
The second patch is another preparation change which moves
can_set_static_ctrlmode() from dev.h to dev.c.
The third patch populates the MTU minimum and maximum value.
The fourth patch is just a clean-up to remove the old
can_change_mtu().
The fourth and last patch comes as a bonus content and modifies the
default MTU of the vcan and vxcan so that CAN XL is on by default.
Note that after this series, the old can_change_mtu() becomes
useless. That function can not yet be removed because some pending
changes from other maintainers' trees still depend on it. It will be
removed in the next development window once all those changes reach
net-next.
Link: https://patch.msgid.link/20250923-can-fix-mtu-v3-0-581bde113f52@kernel.org
[mkl: squashed fixup patch into 3]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In commit 97edec3a11 ("can: enable CAN FD for virtual CAN devices by
default"), vcan and vxcan default MTU was set to CANFD_MTU by default.
The reason was that users were confused on how to activate CAN FD on
virtual interfaces.
Following the introduction of CAN XL, the same logic should be
applied. Set the MTU to CANXL_MTU by default.
The users who really wish to use a Classical CAN only or a CAN FD
virtual device can do respectively:
$ ip link set vcan0 mtu 16
or
$ ip link set vcan0 mtu 72
to force the old behaviour.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-can-fix-mtu-v3-4-581bde113f52@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
By populating:
net_device->min_mtu
and
net_device->max_mtu
the net core infrastructure will automatically:
1. validate that the user's inputs are in range.
2. report those min and max MTU values through the netlink
interface.
Add can_set_default_mtu() which sets the default mtu value as well as
the minimum and maximum values. The logic for the default mtu value
remains unchanged:
- CANFD_MTU if the device has a static CAN_CTRLMODE_FD.
- CAN_MTU otherwise.
Call can_set_default_mtu() each time the CAN_CTRLMODE_FD is modified.
This will guarantee that the MTU value is always consistent with the
control mode flags.
With this, the checks done in can_change_mtu() become fully redundant
and will be removed in an upcoming change and it is now possible to
confirm the minimum and maximum MTU values on a physical CAN interface
by doing:
$ ip --details link show can0
The virtual interfaces (vcan and vxcan) are not impacted by this
change.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-can-fix-mtu-v3-3-581bde113f52@kernel.org
[mkl: squashed https://patch.msgid.link/20250924143644.17622-2-mailhol@kernel.org]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
