commit 1bc8da4e143c0fd8807e061a66d91d5972601ab1 upstream.

When searching for a suitable node that should be used for inserting a new
register, which does not fall within the range of any existing node, we not
only looks for nodes which are directly adjacent to the new register, but
for nodes within a certain proximity. This is done to avoid creating lots
of small nodes with just a few registers spacing in between, which would
increase memory usage as well as tree traversal time.

This means there might be multiple node candidates which fall within the
proximity range of the new register. If we choose the first node we
encounter, under certain register insertion patterns it is possible to end
up with overlapping ranges. This will break order in the rbtree and can
cause the cached register value to become corrupted.

E.g. take the simplified example where the proximity range is 2 and the
register insertion sequence is 1, 4, 2, 3, 5.
 * Insert of register 1 creates a new node, this is the root of the rbtree
 * Insert of register 4 creates a new node, which is inserted to the right
   of the root.
 * Insert of register 2 gets inserted to the first node
 * Insert of register 3 gets inserted to the first node
 * Insert of register 5 also gets inserted into the first node since
   this is the first node encountered and it is within the proximity range.
   Now there are two overlapping nodes.

To avoid this always choose the node that is closest to the new register.
This will ensure that nodes will not overlap. The tree traversal is still
done as a binary search, we just don't stop at the first node found. So the
complexity of the algorithm stays within the same order.

Ideally if a new register is in the range of two adjacent blocks those
blocks should be merged, but that is a much more invasive change and left
for later.

The issue was initially introduced in commit 472fdec7380c ("regmap: rbtree:
Reduce number of nodes, take 2"), but became much more exposed by commit
6399aea629b0 ("regmap: rbtree: When adding a reg do a bsearch for target
node") which changed the order in which nodes are looked-up.

Fixes: 6399aea629b0 ("regmap: rbtree: When adding a reg do a bsearch for target node")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Specifically for the case of reads that use the Extended Register
Read Long command, a multi-byte read operation is broken up into
8-byte chunks.  However the call to spmi_ext_register_readl() is
incorrectly passing 'val_size', which if greater than 8 will
always fail.  The argument should instead be 'len'.

Fixes: c9afbb05a9ff ("regmap: spmi: support base and extended register spaces")
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

Otherwise the DT parsing will default to big endian if nothing is
specified.

Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Since we changed to do formatting in the bus we now skip all the format
parsing that the core does for its data marshalling code.  This means
that we skip the DT parsing it does which breaks some systems, we need
to add an explict call in the MMIO code to do this.

Reported-by: Alexander Stein <alexander.stein@systec-electronic.com>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

internal.h is using dev_name() but doesn't include device.h which
defines it.  Add an explicit include to avoid build problems due to
this.

Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

If max_register is unset, regcache_flat_get_index will return 0 and only
memory for 1 unsigned int will be allocated, resulting in writing out
of bounds.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Setting the flag 'cache_bypass' will bypass the cache not the hardware.
Fix this comment here.

Fixes: 0eef6b0415f5 ("regmap: Fix doc comment")
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Currently when selecting value endianness we check the register
endiannes, not the value endianness.

Reported-by: Alexander Stein <alexander.stein@systec-electronic.com>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>