With devices which have a dense and small register map but placed at a large
offset the global cache_present bitmap imposes a huge memory overhead. Making
the cache_present per rbtree node avoids the issue and easily reduces the memory
footprint by a factor of ten. For devices with a more sparse map or without a
large base register offset the memory usage might increase slightly by a few
bytes, but not significantly. E.g. for a device which has ~50 registers at
offset 0x4000 the memory footprint of the register cache goes down form 2496
bytes to 175 bytes.
Moving the bitmap to a per node basis means that the handling of the bitmap is
now cache implementation specific and can no longer be managed by the core. The
regcache_sync_block() function is extended by a additional parameter so that the
cache implementation can tell the core which registers in the block are set and
which are not. The parameter is optional and if NULL the core assumes that all
registers are set. The rbtree cache also needs to implement its own drop
callback instead of relying on the core to handle this.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Support for reducing the number of nodes and memory consumption of the rbtree
cache by allowing for small unused holes in the node's register cache block was
initially added in commit 0c7ed856 ("regmap: Cut down on the average # of nodes
in the rbtree cache"). But the commit had problems and so its effect was
reverted again in commit 4e67fb5 ("regmap: rbtree: Fix overlapping rbnodes.").
This patch brings the feature back of reducing the average number of nodes,
which will speedup node look-up, while at the same time also reducing the memory
usage of the rbtree cache. This patch takes a slightly different approach than
the original patch though. It modifies the adjacent node look-up to not only
consider nodes that are just one to the left or the right of the register but
any node that falls in a certain range around the register. The range is
calculated based on how much memory it would take to allocate a new node
compared to how much memory it takes adding a set of unused registers to an
existing node. E.g. if a node takes up 24 bytes and each register in a block
uses 1 byte the range will be from the register address - 24 to the register
address + 24. If we find a node that falls within this range it is cheaper or as
expensive to add the register to the existing node and have a couple of unused
registers in the node's cache compared to allocating a new node.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
A register which is adjacent to a node will either be left to the first
register or right to the last register. It will not be within the node's range,
so there is no point in checking for each register cached by the node whether
the new register is next to it. It is sufficient to check whether the register
comes before the first register or after the last register of the node.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
The regmap_debugfs_get_dump_start() function maps from a file offset to the
register that can be found at that position in the file. This is done using a
look-up table. Commit d6814a7d ("regmap: debugfs: Suppress cache for partial
register files") added a check to bypass the look-up table for partial register
files, since the offsets in that table are only correct for the full register
file. The check incorrectly uses the file offset instead of the register base
address and returns it. This will cause the file offset to be interpreted as a
register address which will result in a incorrect output from the registers file
for all reads except at position 0.
The issue can easily be reproduced by doing small reads the registers file, e.g.
`dd if=registers bs=10 count=5`.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org
There are a couple of calculations, which convert between register addresses and
block indices, in regcache_rbtree_sync() and regcache_rbtree_node_alloc() which
assume that reg_stride is 1. This will break the rb cache for configurations
which do not use a reg_stride of 1.
Also rename 'base' in regcache_rbtree_sync() to 'start' to avoid confusion with
'base_reg'.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
It may be useful to register multiple patches with regmap, for example
one that depends on the device revision and one that depends on the system
configuration. Add support for doing this, appending any new patches to
the existing patches.
Signed-off-by: Mark Brown <broonie@linaro.org>
The regmap_writeable() check should not be done in
regcache_write() because this prevents read-only
registers to be cached. After a read on a read-only
register its value will not be stored in the cache
and the next time someone will try to read it the
value will be read from the bus instead of the
cache.
Instead the regmap_writeable() check should be done
in _regmap_write() to prevent callers from writing
to read-only registers.
Signed-off-by: Ionut Nicu <ioan.nicu.ext@nsn.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
In the initial case when no reg_defaults values are
provided and no register value was added to the cache
yet, the cache_present bitmap is NULL. If this function
is invoked for any register it should return false
(i.e. the register is not cached) instead of true.
Signed-off-by: Ionut Nicu <ioan.nicu.ext@nsn.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
I see no reason why a virtual range shouldn't be allowed to cover its
own data window if the page selection register is in the same place
on every page.
For chips which use paged access for all of their registers, but only
when connected via I2C, and which can access the whole register space
directly when connected via SPI, this allows to avoid acrobatics with
the register ranges by simply mapping the I2C ranges over the data
window beginning at 0x0, and then using linear access for the SPI
variant.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
regcache_sync_block_raw_flush() expects the address of the register after last
register that needs to be synced as its parameter. But the last call to
regcache_sync_block_raw_flush() in regcache_sync_block_raw() passes the address
of the last register in the block. This effectively always skips over the last
register in a block, even if it needs to be synced. In order to fix it increase
the address by one register.
The issue was introduced in commit 75a5f89 ("regmap: cache: Write consecutive
registers in a single block write").
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
In case the hardware interrupt mask register does not prevent the chip level
irq from being asserted by the corresponding interrupt status bit, already
set interrupt bits should to be cleared once after masking them during
initialization. Add a flag to let drivers enable this behavior.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Pull driver core patches from Greg KH:
"Here are some driver core patches for 3.11-rc2. They aren't really
bugfixes, but a bunch of new helper macros for drivers to properly
create attribute groups, which drivers and subsystems need to fix up a
ton of race issues with incorrectly creating sysfs files (binary and
normal) after userspace has been told that the device is present.
Also here is the ability to create binary files as attribute groups,
to solve that race condition, which was impossible to do before this,
so that's my fault the drivers were broken.
The majority of the .c changes is indenting and moving code around a
bit. It affects no existing code, but allows the large backlog of 70+
patches that I already have created to start flowing into the
different subtrees, instead of having to live in my driver-core tree,
causing merge nightmares in linux-next for the next few months.
These were finalized too late for the -rc1 merge window, which is why
they were didn't make that pull request, testing and review from
others didn't happen until a few weeks ago, and then there's the whole
distraction of the past few days, which prevented these from getting
to you sooner, sorry about that.
Oh, and there's a bugfix for the documentation build warning in here
as well. All of these have been in linux-next this week, with no
reported problems"
* tag 'driver-core-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
driver-core: fix new kernel-doc warning in base/platform.c
sysfs: use file mode defines from stat.h
sysfs: add more helper macro's for (bin_)attribute(_groups)
driver core: add default groups to struct class
driver core: Introduce device_create_groups
sysfs: prevent warning when only using binary attributes
sysfs: add support for binary attributes in groups
driver core: device.h: add RW and RO attribute macros
sysfs.h: add BIN_ATTR macro
sysfs.h: add ATTRIBUTE_GROUPS() macro
sysfs.h: add __ATTR_RW() macro
Pull phase two of __cpuinit removal from Paul Gortmaker:
"With the __cpuinit infrastructure removed earlier, this group of
commits only removes the function/data tagging that was done with the
various (now no-op) __cpuinit related prefixes.
Now that the dust has settled with yesterday's v3.11-rc1, there
hopefully shouldn't be any new users leaking back in tree, but I think
we can leave the harmless no-op stubs there for a release as a
courtesy to those who still have out of tree stuff and weren't paying
attention.
Although the commits are against the recent tag to allow for minor
context refreshes for things like yesterday's v3.11-rc1~ slab content,
the patches have been largely unchanged for weeks, aside from such
trivial updates.
For detail junkies, the largely boring and mostly irrelevant history
of the patches can be viewed at:
http://git.kernel.org/cgit/linux/kernel/git/paulg/cpuinit-delete.git
If nothing else, I guess it does at least demonstrate the level of
involvement required to shepherd such a treewide change to completion.
This is the same repository of patches that has been applied to the
end of the daily linux-next branches for the past several weeks"
* 'cpuinit_phase2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (28 commits)
block: delete __cpuinit usage from all block files
drivers: delete __cpuinit usage from all remaining drivers files
kernel: delete __cpuinit usage from all core kernel files
rcu: delete __cpuinit usage from all rcu files
net: delete __cpuinit usage from all net files
acpi: delete __cpuinit usage from all acpi files
hwmon: delete __cpuinit usage from all hwmon files
cpufreq: delete __cpuinit usage from all cpufreq files
clocksource+irqchip: delete __cpuinit usage from all related files
x86: delete __cpuinit usage from all x86 files
score: delete __cpuinit usage from all score files
xtensa: delete __cpuinit usage from all xtensa files
openrisc: delete __cpuinit usage from all openrisc files
m32r: delete __cpuinit usage from all m32r files
hexagon: delete __cpuinit usage from all hexagon files
frv: delete __cpuinit usage from all frv files
cris: delete __cpuinit usage from all cris files
metag: delete __cpuinit usage from all metag files
tile: delete __cpuinit usage from all tile files
sh: delete __cpuinit usage from all sh files
...
Fix new kernel-doc warning in drivers/base/platform.c:
Warning(drivers/base/platform.c:528): No description found for parameter 'owner'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should be using groups, not attribute lists, for classes to allow
subdirectories, and soon, binary files. Groups are just more flexible
overall, so add them.
The dev_attrs list will go away after all in-kernel users are converted
to use dev_groups.
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
device_create_groups lets callers create devices as well as associated
sysfs attributes with a single call. This avoids race conditions seen
if sysfs attributes on new devices are created later.
[fixed up comment block placement and add checks for printk buffer
formats - gregkh]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the following sparse warnings:
drivers/base/regmap/regmap.c:305:13: warning: context imbalance in 'regmap_lock_spinlock' - wrong count at exit
drivers/base/regmap/regmap.c:314:13: warning: context imbalance in 'regmap_unlock_spinlock' - unexpected unlock
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Pull regmap fix from Mark Brown:
"Fix regmap crash for async operation on busless maps
This fixes a crash if something tries to do an asynchronous operation
on busless maps which was introduced during the merge window"
* tag 'regmap-v3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: cache: bail in regmap_async_complete() for bus-less maps
Mark Brown
Lars-Peter Clausen
Ionut Nicu
Philipp Zabel
Linus Torvalds
Randy Dunlap
Greg Kroah-Hartman
Guenter Roeck
Fabio Estevam