kernel/arch/arm/mach-rpc, branch linux-6.2.y

ARM: Kconfig: clean up platform selection

2022-08-18T14:44:59Z

The top-level platform selection is mostly meaningless these days after almost everything is sorted below the CONFIG_ARCH_MULTIPLATFORM, with the only exception being the 20+ year old StrongARM based machines. Make this more consistent by removing the entire choice statement and moving the StrongARM specific options into regular platform specific Kconfig files. The three platforms (footbridge, rpc and sa1100) are still mutually exclusive and cannot coexist with other ARMv4/v5 machines, but since there are only three of them and we will not add more, this can be expressed using Kconfig 'depends on' statements. Signed-off-by: Arnd Bergmann

ARM: remove obsolete Makefile.boot infrastructure

2022-08-18T14:44:59Z

There are a number of old Makefile.boot files that remain from the multiplatform conversion, and three that are still in use. These provide the "ZRELADDR", "PARAMS_PHYS" and "INITRD_PHYS" values that are platform specific. It turns out that we can generally just derive this from information that is available elsewhere: - ZRELADDR is normally detected at runtime with the CONFIG_AUTO_ZRELADDR flag, but also needed to be passed to for 'make uImage'. In a multiplatform kernel, one always has to pass this as the $(LOADADDR) variable, but in the StrongARM kernels we can derive it from the sum of $(CONFIG_PHYS_OFFSET) and $(TEXT_OFFSET) that are already known. - PARAMS_PHYS and INITRD_PHYS are only used for bootpImage, which in turn is only used for the pre-ATAGS 'param_struct' based boot interface on StrongARM based machines with old boot loaders. They can both be derived from CONFIG_PHYS_OFFSET and a machine specific offset for the initrd, so all of the logic for these can be part of arch/arm/boot/bootp/Makefile. Signed-off-by: Arnd Bergmann

ARM: riscpc: use GENERIC_IRQ_MULTI_HANDLER

2021-12-03T17:43:38Z

This is one of the last platforms using the old entry path. While this code path is spread over a few files, it is fairly straightforward to convert it into an equivalent C version, leaving the existing algorithm and all the priority handling the same. Unlike most irqchip drivers, this means reading the status register(s) in a loop and always handling the highest-priority irq first. The IOMD_IRQREQC and IOMD_IRQREQD registers are not actaully used here, but I left the code in place for the time being, to keep the conversion as direct as possible. It could be removed in a cleanup on top. Signed-off-by: Arnd Bergmann [ardb: drop obsolete IOMD_IRQREQC/IOMD_IRQREQD handling] Signed-off-by: Ard Biesheuvel Tested-by: Marc Zyngier Tested-by: Vladimir Murzin # ARMv7M

Merge tag 'printk-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2021-09-02T01:41:13Z

Pull printk updates from Petr Mladek: - Optionally, provide an index of possible printk messages via /printk/index/. It can be used when monitoring important kernel messages on a farm of various hosts. The monitor has to be updated when some messages has changed or are not longer available by a newly deployed kernel. - Add printk.console_no_auto_verbose boot parameter. It allows to generate crash dump even with slow consoles in a reasonable time frame. - Remove printk_safe buffers. The messages are always stored directly to the main logbuffer, even in NMI or recursive context. Also it allows to serialize syslog operations by a mutex instead of a spin lock. - Misc clean up and build fixes. * tag 'printk-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk/index: Fix -Wunused-function warning lib/nmi_backtrace: Serialize even messages about idle CPUs printk: Add printk.console_no_auto_verbose boot parameter printk: Remove console_silent() lib/test_scanf: Handle n_bits == 0 in random tests printk: syslog: close window between wait and read printk: convert @syslog_lock to mutex printk: remove NMI tracking printk: remove safe buffers printk: track/limit recursion lib/nmi_backtrace: explicitly serialize banner and regs printk: Move the printk() kerneldoc comment to its new home printk/index: Fix warning about missing prototypes MIPS/asm/printk: Fix build failure caused by printk printk: index: Add indexing support to dev_printk printk: Userspace format indexing support printk: Rework parse_prefix into printk_parse_prefix printk: Straighten out log_flags into printk_info_flags string_helpers: Escape double quotes in escape_special printk/console: Check consistent sequence number when handling race in console_unlock()

Merge 5.14-rc5 into driver-core-next

2021-08-09T07:03:47Z

We need the driver core fixes in here as well. Signed-off-by: Greg Kroah-Hartman

ARM: riscpc: Fix fall-through warning for Clang

2021-07-29T17:51:00Z

Fix the following fallthrough warning: arch/arm/mach-rpc/riscpc.c:52:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough] default: ^ arch/arm/mach-rpc/riscpc.c:52:2: note: insert 'break;' to avoid fall-through default: ^ break; Reported-by: kernel test robot Link: https://lore.kernel.org/lkml/202107260355.bF00i5bi-lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva

bus: Make remove callback return void

2021-07-21T09:53:42Z

The driver core ignores the return value of this callback because there is only little it can do when a device disappears. This is the final bit of a long lasting cleanup quest where several buses were converted to also return void from their remove callback. Additionally some resource leaks were fixed that were caused by drivers returning an error code in the expectation that the driver won't go away. With struct bus_type::remove returning void it's prevented that newly implemented buses return an ignored error code and so don't anticipate wrong expectations for driver authors. Reviewed-by: Tom Rix (For fpga) Reviewed-by: Mathieu Poirier Reviewed-by: Cornelia Huck (For drivers/s390 and drivers/vfio) Acked-by: Russell King (Oracle) (For ARM, Amba and related parts) Acked-by: Mark Brown Acked-by: Chen-Yu Tsai (for sunxi-rsb) Acked-by: Pali Rohár Acked-by: Mauro Carvalho Chehab (for media) Acked-by: Hans de Goede (For drivers/platform) Acked-by: Alexandre Belloni Acked-By: Vinod Koul Acked-by: Juergen Gross (For xen) Acked-by: Lee Jones (For mfd) Acked-by: Johannes Thumshirn (For mcb) Acked-by: Johan Hovold Acked-by: Srinivas Kandagatla (For slimbus) Acked-by: Kirti Wankhede (For vfio) Acked-by: Maximilian Luz Acked-by: Heikki Krogerus (For ulpi and typec) Acked-by: Samuel Iglesias Gonsálvez (For ipack) Acked-by: Geoff Levand (For ps3) Acked-by: Yehezkel Bernat (For thunderbolt) Acked-by: Alexander Shishkin (For intel_th) Acked-by: Dominik Brodowski (For pcmcia) Acked-by: Rafael J. Wysocki (For ACPI) Acked-by: Bjorn Andersson (rpmsg and apr) Acked-by: Srinivas Pandruvada (For intel-ish-hid) Acked-by: Dan Williams (For CXL, DAX, and NVDIMM) Acked-by: William Breathitt Gray (For isa) Acked-by: Stefan Richter (For firewire) Acked-by: Benjamin Tissoires (For hid) Acked-by: Thorsten Scherer (For siox) Acked-by: Sven Van Asbroeck (For anybuss) Acked-by: Ulf Hansson (For MMC) Acked-by: Wolfram Sang # for I2C Acked-by: Sudeep Holla Acked-by: Geert Uytterhoeven Acked-by: Dmitry Torokhov Acked-by: Finn Thain Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

printk: Userspace format indexing support

2021-07-19T09:57:48Z

We have a number of systems industry-wide that have a subset of their functionality that works as follows: 1. Receive a message from local kmsg, serial console, or netconsole; 2. Apply a set of rules to classify the message; 3. Do something based on this classification (like scheduling a remediation for the machine), rinse, and repeat. As a couple of examples of places we have this implemented just inside Facebook, although this isn't a Facebook-specific problem, we have this inside our netconsole processing (for alarm classification), and as part of our machine health checking. We use these messages to determine fairly important metrics around production health, and it's important that we get them right. While for some kinds of issues we have counters, tracepoints, or metrics with a stable interface which can reliably indicate the issue, in order to react to production issues quickly we need to work with the interface which most kernel developers naturally use when developing: printk. Most production issues come from unexpected phenomena, and as such usually the code in question doesn't have easily usable tracepoints or other counters available for the specific problem being mitigated. We have a number of lines of monitoring defence against problems in production (host metrics, process metrics, service metrics, etc), and where it's not feasible to reliably monitor at another level, this kind of pragmatic netconsole monitoring is essential. As one would expect, monitoring using printk is rather brittle for a number of reasons -- most notably that the message might disappear entirely in a new version of the kernel, or that the message may change in some way that the regex or other classification methods start to silently fail. One factor that makes this even harder is that, under normal operation, many of these messages are never expected to be hit. For example, there may be a rare hardware bug which one wants to detect if it was to ever happen again, but its recurrence is not likely or anticipated. This precludes using something like checking whether the printk in question was printed somewhere fleetwide recently to determine whether the message in question is still present or not, since we don't anticipate that it should be printed anywhere, but still need to monitor for its future presence in the long-term. This class of issue has happened on a number of occasions, causing unhealthy machines with hardware issues to remain in production for longer than ideal. As a recent example, some monitoring around blk_update_request fell out of date and caused semi-broken machines to remain in production for longer than would be desirable. Searching through the codebase to find the message is also extremely fragile, because many of the messages are further constructed beyond their callsite (eg. btrfs_printk and other module-specific wrappers, each with their own functionality). Even if they aren't, guessing the format and formulation of the underlying message based on the aesthetics of the message emitted is not a recipe for success at scale, and our previous issues with fleetwide machine health checking demonstrate as much. This provides a solution to the issue of silently changed or deleted printks: we record pointers to all printk format strings known at compile time into a new .printk_index section, both in vmlinux and modules. At runtime, this can then be iterated by looking at /printk/index/, which emits the following format, both readable by humans and able to be parsed by machines: $ head -1 vmlinux; shuf -n 5 vmlinux # filename:line function "format" <5> block/blk-settings.c:661 disk_stack_limits "%s: Warning: Device %s is misaligned\n" <4> kernel/trace/trace.c:8296 trace_create_file "Could not create tracefs '%s' entry\n" <6> arch/x86/kernel/hpet.c:144 _hpet_print_config "hpet: %s(%d):\n" <6> init/do_mounts.c:605 prepare_namespace "Waiting for root device %s...\n" <6> drivers/acpi/osl.c:1410 acpi_no_auto_serialize_setup "ACPI: auto-serialization disabled\n" This mitigates the majority of cases where we have a highly-specific printk which we want to match on, as we can now enumerate and check whether the format changed or the printk callsite disappeared entirely in userspace. This allows us to catch changes to printks we monitor earlier and decide what to do about it before it becomes problematic. There is no additional runtime cost for printk callers or printk itself, and the assembly generated is exactly the same. Signed-off-by: Chris Down Cc: Petr Mladek Cc: Jessica Yu Cc: Sergey Senozhatsky Cc: John Ogness Cc: Steven Rostedt Cc: Greg Kroah-Hartman Cc: Johannes Weiner Cc: Kees Cook Reviewed-by: Petr Mladek Tested-by: Petr Mladek Reported-by: kernel test robot Acked-by: Andy Shevchenko Acked-by: Jessica Yu # for module.{c,h} Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/e42070983637ac5e384f17fbdbe86d19c7b212a5.1623775748.git.chris@chrisdown.name

ARM: rpc: use legacy_timer_tick

2020-10-30T20:57:05Z

rpc is the only user of the timer_tick() function now, and can just call the newly added generic version instead. Reviewed-by: Linus Walleij Signed-off-by: Arnd Bergmann

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva