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
Commit f8bd822cb ("regmap: cache: Factor out block sync") made
regcache_rbtree_sync() call regmap_async_complete(), which in turn does
not check for map->bus before dereferencing it.
This causes a NULL pointer dereference on bus-less maps.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: stable@vger.kernel.org [v3.10 only]
Signed-off-by: Mark Brown <broonie@linaro.org>
It is common to access regmap registers at bit level, using
regmap_update_bits or regmap_read functions, however the end user has to
take care of a mask or shifting. This becomes overhead when such use
cases are high. Having a common function to do this is much convenient
and less error prone.
The idea of regmap_field is simple, regmap_field gives a logical
structure to bits of the regmap register, and the driver can use this
logical entity without the knowledge of the bit positions and masks all
over the code. This way code looks much neat and it need not handle the
masks, shifts every time it access the those entities.
With this new regmap_field_read/write apis the end user can setup a
regmap field using regmap_field_init and use the return regmap_field to
read write the register field without worrying about the masks or
shifts.
Also this apis will be useful for drivers which are based on regmaps,
like some clocks or pinctrls which can work on the regmap_fields
directly without having to worry about bit positions.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Currently all register maps with a cache need to provide a volatile
callback since the default is to assume all registers are volatile.
This is not sensible if we have a cache so change the default to be
fully cached if a cache is provided.
Signed-off-by: Mark Brown <broonie@linaro.org>
regmap-mmio uses a spinlock with spin_lock() and spin_unlock() for locking.
To be able to use the regmap API from different contexts (atomic vs non-atomic),
without the risk of race conditions, we need to use spin_lock_irqsave() and
spin_lock_irqrestore() instead. A new field, the spinlock_flags field, is added
to regmap struct to store the flags between regmap_{,un}lock_spinlock(). The
spinlock_flags field itself is also protected by the spinlock.
Thanks to Stephen Warren for the suggestion of this particular solution.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
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>
This reverts commit bc8ce4 (regmap: don't corrupt work buffer in
_regmap_raw_write()) since it turns out that it can cause issues when
taken in isolation from the other changes in -next that lead to its
discovery. On the basis that nobody noticed the problems for quite some
time without that subsequent work let's drop it from v3.9.
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>
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>
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
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>
Trace when we start and complete async writes, and when we start and
finish blocking for their completion. This is useful for performance
analysis of the resulting I/O patterns.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
