The existing cpumap_print_to_pagebuf() is used by cpu topology and other
drivers to export hexadecimal bitmask and decimal list to userspace by
sysfs ABI.
Right now, those drivers are using a normal attribute for this kind of
ABIs. A normal attribute typically has show entry as below:
static ssize_t example_dev_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
...
return cpumap_print_to_pagebuf(true, buf, &pmu_mmdc->cpu);
}
show entry of attribute has no offset and count parameters and this
means the file is limited to one page only.
cpumap_print_to_pagebuf() API works terribly well for this kind of
normal attribute with buf parameter and without offset, count:
static inline ssize_t
cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
{
return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
nr_cpu_ids);
}
The problem is once we have many cpus, we have a chance to make bitmask
or list more than one page. Especially for list, it could be as complex
as 0,3,5,7,9,...... We have no simple way to know it exact size.
It turns out bin_attribute is a way to break this limit. bin_attribute
has show entry as below:
static ssize_t
example_bin_attribute_show(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t offset, size_t count)
{
...
}
With the new offset and count parameters, this makes sysfs ABI be able
to support file size more than one page. For example, offset could be
>= 4096.
This patch introduces cpumap_print_bitmask/list_to_buf() and their bitmap
infrastructure bitmap_print_bitmask/list_to_buf() so that those drivers
can move to bin_attribute to support large bitmask and list. At the same
time, we have to pass those corresponding parameters such as offset, count
from bin_attribute to this new API.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: "Ma, Jianpeng" <jianpeng.ma@intel.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Link: https://lore.kernel.org/r/20210806110251.560-2-song.bao.hua@hisilicon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull gpio updates from Bartosz Golaszewski:
"One new driver, support for new models in existing ones, dt-bindings
conversions for several modules and improvements all over the place.
Summary:
- new driver for the IDT 79RC3243x GPIO controller
- device tree bindings coversion to YAML for the following drivers:
gpio-rk3328-grf, gpio-omap, gpio-davinci, gpio-zynq, gpio-stp,
gpio-pcf857x
- cleanup of probe functions in many drivers from Alexandru Ardelean,
mostly dropping unnecessary calls to platform_set_drvdata() and
removing error messages where none are needed (handled by the
subsystem already)
- several improvements to the core gpiolib and the sysfs interface
code from Andy Shevchenko
- conversion of the gpio-xilinx driver to using the bitmap API +
improvements of suspend/resume handling + minor tweaks
- convert the gpio-stmpe to using devres helpers exclusively in probe
for improved robustness
- updates for the generic gpio-regmap driver
- updates for the gpio-dwapb driver
- support for a new model in gpio-pca953x
- cleanups in gpio-tegra186, gpio-104-idio-16, gpio-mxs & gpio-xgene
- slight code refactoring of the gpio-zynq driver
- documentation fixes from Mauro Carvalho Chehab
- a bunch of minor tweaks and improvements all over the place"
* tag 'gpio-updates-for-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (57 commits)
docs: driver-api: gpio: using-gpio.rst: avoid using ReST :doc:`foo` markup
dt-bindings: gpio: pcf857x: Convert to json-schema
gpio: mxs: Prefer unsigned int to bare use of unsigned
dt-bindings: gpio: stp: convert to json-schema
dt-bindings: gpio: zynq: convert bindings to YAML
dt-bindings: gpio: gpio-davinci: Convert to json-schema
gpio: pca953x: Add support for the On Semi pca9655
gpio: gpio-xilinx: update on suspend and resume calls
gpio: zynq: Check return value of irq_get_irq_data
gpio: zynq: Check return value of pm_runtime_get_sync
gpio: zynq: use module_platform_driver to simplify the code
gpio: idt3243x: Fix return value check in idt_gpio_probe()
MAINTAINERS: update ti,omap-gpio.yaml reference
dt-bindings: gpio: Add devicetree binding for IDT 79RC32434 GPIO controller
gpio: Add support for IDT 79RC3243x GPIO controller
gpio: regmap: move drvdata to config data
gpio-dwapb: Drop unused headers and sort the rest
gpio: gpio-regmap: Use devm_add_action_or_reset()
gpio: dwapb: Switch to use fwnode_irq_get()
gpio: dwapb: Drop redundant check in dwapb_irq_set_type()
...
Currently the bitmap_remap() and bitmap_bitremap() are available
only for CONFIG_NUMA=y case, while some users may benefit out of it
and being independent to NUMA code. Make them available to users
by moving out of ifdeffery and exporting for modules.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Neeli Srinivas <sneeli@xilinx.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
RCU code supports an 'all' group as a special case when parsing rcu_nocbs
parameter. This patch moves the 'all' support to the core bitmap_parse
code, so that all bitmap users can enjoy this extension.
Moving 'all' parsing to a bitmap_parse level also allows users to pass
patterns together with 'all' in regular group:pattern format, for example,
"rcu_nocbs=all:1/2" would offload all the even-numbered CPUs regardless
of the number of CPUs on the system.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Pull gpio updates from Bartosz Golaszewski:
- new driver for the Realtek Otto GPIO controller
- ACPI support for gpio-mpc8xxx
- edge event support for gpio-sch (+ Kconfig fixes)
- Kconfig improvements in gpio-ich
- fixes to older issues in gpio-mockup
- ACPI quirk for ignoring EC wakeups on Dell Venue 10 Pro 5055
- improve the GPIO aggregator code by using more generic interfaces
instead of reimplementing them in the driver
- convert the DT bindings for gpio-74x164 to yaml
- documentation improvements
- a slew of other minor fixes and improvements to GPIO drivers
* tag 'gpio-updates-for-v5.13-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (34 commits)
dt-bindings: gpio: add YAML description for rockchip,gpio-bank
gpio: mxs: remove useless function
dt-bindings: gpio: fairchild,74hc595: Convert to json-schema
gpio: it87: remove unused code
gpio: 104-dio-48e: Fix coding style issues
gpio: mpc8xxx: Add ACPI support
gpio: ich: Switch to be dependent on LPC_ICH
gpio: sch: Drop MFD_CORE selection
gpio: sch: depends on LPC_SCH
gpiolib: acpi: Add quirk to ignore EC wakeups on Dell Venue 10 Pro 5055
gpio: sch: Hook into ACPI GPE handler to catch GPIO edge events
gpio: sch: Add edge event support
gpio: aggregator: Replace custom get_arg() with a generic next_arg()
lib/cmdline: Export next_arg() for being used in modules
gpio: omap: Use device_get_match_data() helper
gpio: Add Realtek Otto GPIO support
dt-bindings: gpio: Binding for Realtek Otto GPIO
docs: kernel-parameters: Add gpio_mockup_named_lines
docs: kernel-parameters: Move gpio-mockup for alphabetic order
lib: bitmap: provide devm_bitmap_alloc() and devm_bitmap_zalloc()
...
While this is done for all bitmaps, the original use case in mind was
for CPU masks and cpulist_parse() as described below.
It seems that a common configuration is to use the 1st couple cores for
housekeeping tasks. This tends to leave the remaining ones to form a
pool of similarly configured cores to take on the real workload of
interest to the user.
So on machine A - with 32 cores, it could be 0-3 for "system" and then
4-31 being used in boot args like nohz_full=, or rcu_nocbs= as part of
setting up the worker pool of CPUs.
But then newer machine B is added, and it has 48 cores, and so while
the 0-3 part remains unchanged, the pool setup cpu list becomes 4-47.
Multiple deployment becomes easier when we can just simply replace 31
and 47 with "N" and let the system substitute in the actual number at
boot; a number that it knows better than we do.
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Yury Norov <yury.norov@gmail.com> # move it from CPU code
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
There are two ascii art drawings there. Use a block markup tag there
in order to get rid of those warnings:
./lib/bitmap.c:189: WARNING: Unexpected indentation.
./lib/bitmap.c:190: WARNING: Block quote ends without a blank line; unexpected unindent.
./lib/bitmap.c:190: WARNING: Unexpected indentation.
./lib/bitmap.c:191: WARNING: Line block ends without a blank line.
It should be noticed that there's actually a syntax violation
right now, as something like:
/**
...
@src:
will be handled as a definition for @src parameter, and not as
part of a diagram. So, we need to add something before it, in
order for this to be processed the way it should.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/1e2568fdfa838c1a0d8cc2a1d70dd4b6de99bfb1.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The new bitmap function bitmap_cut() copies bits from source to
destination by removing the region specified by parameters first
and cut, and remapping the bits above the cut region by right
shifting them.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The IPI code of x86 needs to evaluate whether the target cpumask is equal
to the cpu_online_mask or equal except for the calling CPU.
To replace the current implementation which requires the usage of a
temporary cpumask, which might involve allocations, add a new function
which compares a cpumask to the result of two other cpumasks which are
or'ed together before comparison.
This allows to make the required decision in one go and the calling code
then can check for the calling CPU being set in the target mask with
cpumask_test_cpu().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.585449120@linutronix.de
