This will bring no meaningful benefit by itself, it is done as a separate
commit to aid bisection if there are problems with the following commits
adding support for coalescing adjacent writes.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Mainly useful internally but exported since this is a public API that's
being checked for.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Provide a helper to do the size based index into a block of registers and
use it when reading a value.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This patch aims to bring down the average number of nodes
in the rbtree cache and increase the average number of registers
per node. This should improve general lookup and traversal times.
This is achieved by setting the minimum size of a block within the
rbnode to the size of the rbnode itself. This will essentially
cache possibly non-existent registers so to combat this scenario,
we keep a separate bitmap in memory which keeps track of which register
exists. The memory overhead of this change is likely in the order of
~5-10%, possibly less depending on the register file layout. On my test
system with a bitmap of ~4300 bits and a relatively sparse register
layout, the memory requirements for the entire cache did not increase
(the cutting down of nodes which was about 50% of the original number
compensated the situation).
A second patch that can be built on top of this can look at the
ratio `sizeof(*rbnode) / map->cache_word_size' in order to suitably
adjust the block length of each block.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This allows the cache to sync values directly to the device when stored
in native format and also allows asynchronous I/O.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
_regmap_raw_write() contains code to call regcache_write() to write
values to the cache. That code calls memcpy() to copy the value data to
the start of the work_buf. However, at least when _regmap_raw_write() is
called from _regmap_bus_raw_write(), the value data is in the work_buf,
and this memcpy() operation may over-write part of that value data,
depending on the value of reg_bytes + pad_bytes. At least when using
reg_bytes==1 and pad_bytes==0, corruption of the value data does occur.
To solve this, remove the memcpy() operation, and modify the subsequent
.parse_val() call to parse the original value buffer directly.
At least in the case of 8-bit register address and 16-bit values, and
writes of single registers at a time, this memcpy-then-parse combination
used to cancel each-other out; for a work-buffer containing xx 89 03,
the memcpy changed it to 89 03 03, and the parse_val changed it back to
89 89 03, thus leaving the value uncorrupted. This appears completely
accidental though. Since commit 8a819ff "regmap: core: Split out in
place value parsing", .parse_val only returns the parsed value, and does
not modify the buffer, and hence does not (accidentally) undo the
corruption caused by memcpy(). This caused bogus values to get written
to HW, thus preventing e.g. audio playback on systems with a WM8903
CODEC. This patch fixes that.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Display the name for the chip rather than just the primary IRQ so it is
clearer what exactly has failed.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Whenever a struct device_attribute is registered
with mismatched permissions - read permission without
a show routine or write permission without store
routine - we will issue a big warning so we catch
those early enough.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The last register block, which falls into the specified range, is not handled
correctly. The formula which calculates the number of register which should be
synced is inverse (and off by one). E.g. if all registers in that block should
be synced only one is synced, and if only one should be synced all (but one) are
synced. To calculate the number of registers that need to be synced we need to
subtract the number of the first register in the block from the max register
number and add one. This patch updates the code accordingly.
The issue was introduced in commit ac8d91c ("regmap: Supply ranges to the sync
operations").
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org
Kay tells me the most appropriate place to expose workqueues to
userland would be /sys/devices/virtual/workqueues/WQ_NAME which is
symlinked to /sys/bus/workqueue/devices/WQ_NAME and that we're lacking
a way to do that outside of driver core as virtual_device_parent()
isn't exported and there's no inteface to conveniently create a
virtual subsystem.
This patch implements subsys_virtual_register() by factoring out
subsys_register() from subsys_system_register() and using it with
virtual_device_parent() as the origin directory. It's identical to
subsys_system_register() other than the origin directory but we aren't
gonna restrict the device names which should be used under it.
This will be used to expose workqueue attributes to userland.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
In the rbtree code we are exposing statistics relating to the
number of nodes/registers of the rbtree cache for each of the
devices. Ensure that `map->debugfs' has been initialized before
we attempt to initialize the debugfs entry for the rbtree cache.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org
Pull ACPI and power management fixes from Rafael J Wysocki:
- Two fixes for the new intel_pstate driver from Dirk Brandewie.
- Fix for incorrect usage of the .find_bridge() callback from struct
acpi_bus_type in the USB core and subsequent removal of that callback
from Rafael J Wysocki.
- ACPI processor driver cleanups from Chen Gang and Syam Sidhardhan.
- ACPI initialization and error messages fix from Joe Perches.
- Operating Performance Points documentation improvement from Nishanth
Menon.
- Fixes for memory leaks and potential concurrency issues and sysfs
attributes leaks during device removal in the core device PM QoS code
from Rafael J Wysocki.
- Calxeda Highbank cpufreq driver simplification from Emilio López.
- cpufreq comment cleanup from Namhyung Kim.
- Fix for a section mismatch in Calxeda Highbank interprocessor
communication code from Mark Langsdorf (this is not a PM fix strictly
speaking, but the code in question went in through the PM tree).
* tag 'pm+acpi-3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq / intel_pstate: Do not load on VM that does not report max P state.
cpufreq / intel_pstate: Fix intel_pstate_init() error path
ACPI / glue: Drop .find_bridge() callback from struct acpi_bus_type
ACPI / glue: Add .match() callback to struct acpi_bus_type
ACPI / porocessor: Beautify code, pr->id is u32 which is never < 0
ACPI / processor: Remove redundant NULL check before kfree
ACPI / Sleep: Avoid interleaved message on errors
PM / QoS: Remove device PM QoS sysfs attributes at the right place
PM / QoS: Fix concurrency issues and memory leaks in device PM QoS
cpufreq: highbank: do not initialize array with a loop
PM / OPP: improve introductory documentation
cpufreq: Fix a typo in comment
mailbox, pl320-ipc: remove __init from probe function
Pull regmap PM fix from Mark Brown:
"A simple fix to stop us leaking a runtime PM reference in the case
where we fail to enable a device."
* tag 'regmap-v3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: irq: call pm_runtime_put in pm_runtime_get_sync failed case
Device PM QoS sysfs attributes, if present during device removal,
are removed from within device_pm_remove(), which is too late,
since dpm_sysfs_remove() has already removed the whole attribute
group they belonged to. However, moving the removal of those
attributes to dpm_sysfs_remove() alone is not sufficient, because
in theory they still can be re-added right after being removed by it
(the device's driver is still bound to it at that point).
For this reason, move the entire desctruction of device PM QoS
constraints to dpm_sysfs_remove() and make it prevent any new
constraints from being added after it has run. Also, move the
initialization of the power.qos field in struct device to
device_pm_init_common() and drop the no longer needed
dev_pm_qos_constraints_init().
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The current device PM QoS code assumes that certain functions will
never be called in parallel with each other (for example, it is
assumed that dev_pm_qos_expose_flags() won't be called in parallel
with dev_pm_qos_hide_flags() for the same device and analogously
for the latency limit), which may be overly optimistic. Moreover,
dev_pm_qos_expose_flags() and dev_pm_qos_expose_latency_limit()
leak memory in error code paths (req needs to be freed on errors)
and __dev_pm_qos_drop_user_request() forgets to free the request.
To fix the above issues put more things under the device PM QoS
mutex to make them mutually exclusive and add the missing freeing
of memory.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This file lists the register ranges in the register map. The condition
to split the range is based on whether the block is readable or not.
Ensure that we lock the `debugfs_off_cache' list whenever we access
and modify the list. There is a possible race otherwise between the
read() operations of the `registers' file and the `range' file.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
We don't need to use any of the file position information
to calculate the base and max register of each block. Just
use the counter directly.
Set `i = base' at the top to avoid GCC flow analysis bugs. The
value of `i' can never be undefined or 0 in the if (c) { ... }.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Currently the value parsing operations both return the parsed value and
modify the passed buffer. This precludes their use in places like the cache
code so split out the in place modification into a new parse_inplace()
operation.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
It's more idiomatic to pass the map structure around and this means we
can use other bits of information from the map.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Mark Brown
Dimitris Papastamos
Stephen Warren
Dmitry Torokhov
Felipe Balbi
Lars-Peter Clausen
Michal Hocko
Tejun Heo
Linus Torvalds
Rafael J. Wysocki