kernel/linux.git/drivers/base/regmap/regcache-flat.c, branch v6.19.11

regcache: flat: Split ->populate() from ->init()

2025-10-31T12:01:54+00:00

Split ->populate() implementation from ->init() code. This decoupling will help for the further changes. Signed-off-by: Andy Shevchenko Reviewed-by: Charles Keepax Link: https://patch.msgid.link/20251031080540.3970776-5-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown

regcache: flat: Remove unneeded check and error message for -ENOMEM

2025-10-31T12:01:53+00:00

There is a convention in the kernel to avoid error messages in the cases of -ENOMEM errors. Besides that, the idea behind using struct_size() and other macros from overflow.h is to saturate the size that the following allocation call will definitely fail, hence the check and the error messaging added in regcache_flat_init() are redundant. Remove them. Acked-by: Sander Vanheule Signed-off-by: Andy Shevchenko Reviewed-by: Charles Keepax Link: https://patch.msgid.link/20251031080540.3970776-4-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown

regmap: warn users about uninitialized flat cache

2025-10-29T12:54:05+00:00

The standard flat cache did not contain any validity info, so the cache was always considered to be entirely valid. Multiple mechanisms exist to initialize the cache on regmap init (defaults, raw defaults, HW init), but not all drivers are using one of these. As a result, their implementation might currently depend on the zero-initialized cache or contain other workarounds. When reading an uninitialized value from the flat cache, warn the user, but maintain the current behavior. This will allow developers to switch to a sparse (flat) cache independently. Signed-off-by: Sander Vanheule Link: https://patch.msgid.link/20251029081248.52607-3-sander@svanheule.net Signed-off-by: Mark Brown

regmap: add flat cache with sparse validity

2025-10-29T12:54:04+00:00

The flat regcache will always assume the data in the cache is valid. Since the cache is preferred over hardware access, this may shadow the actual state of the device. Add a new containing cache structure with the flat data table and a bitmap indicating cache validity. REGCACHE_FLAT will still behave as before, as the validity is ignored. Define new cache type REGCACHE_FLAT_S: a flat cache with sparse validity. The sparse validity is used to determine if a hardware access should occur to initialize the cache on the fly, vs. at regmap init for REGCACHE_FLAT. Contrary to REGCACHE_FLAT, this allows us to implement regcache_ops.drop. Signed-off-by: Sander Vanheule Link: https://patch.msgid.link/20251029081248.52607-2-sander@svanheule.net Signed-off-by: Mark Brown

regcache: use map->alloc_flags also for allocating cache

2024-08-28T12:52:29+00:00

Commit fd4ebc07b4df ("regmap: Hold the regmap lock when allocating and freeing the cache") introduced a locking around the allocating and freeing a regmap cache, so adjust the memory allocation flags to the ones given in the regmap configuration instead of the hardcoded GFP_KERNEL. This fixes the "BUG: sleeping function called from invalid context" introduced by the mentioned commit. Fixes: fd4ebc07b4df ("regmap: Hold the regmap lock when allocating and freeing the cache") Signed-off-by: Marek Szyprowski Link: https://patch.msgid.link/20240828122834.3778031-1-m.szyprowski@samsung.com Signed-off-by: Mark Brown

regmap: rework ->max_register handling

2024-02-05T14:32:35+00:00

When regmap consists of single register, 'regmap' subsystem is unable to understand whether ->max_register is set or not, because in both cases it is equal to zero. It leads to that the logic based on value of ->max_register doesn't work. For example using of REGCACHE_FLAT fails. This patch introduces an extra parameter to regmap config, indicating that zero value in ->max_register is authentic. Signed-off-by: Jan Dakinevich Link: https://lore.kernel.org/r/20240126200836.1829995-1-jan.dakinevich@salutedevices.com Signed-off-by: Mark Brown

regmap: add proper SPDX identifiers on files that did not have them.

2019-04-25T19:22:15+00:00

There were a few files in the regmap code that did not have SPDX identifiers on them, so fix that up. At the same time, remove the "free form" text that specified the license of the file, as that is impossible for any tool to properly parse. Also, as Mark loves // comment markers, convert all of the headers to be the same to make things look consistent :) Signed-off-by: Greg Kroah-Hartman Signed-off-by: Mark Brown

regcache: flat: Un-inline index lookup from cache access

2018-01-08T12:08:57+00:00

This makes the code slightly more readable and allows for cleaner addition of functionality in later patches. Signed-off-by: Andrew F. Davis Signed-off-by: Mark Brown

regcache: flat: Require max_registers to be set

2016-03-29T16:51:04+00:00

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 Signed-off-by: Mark Brown

regcache: flat: Introduce register strider order

2016-02-19T16:12:32+00:00

Here we introduce regcache_flat_get_index(), which using register stride order and bit rotation, will save some memory spaces for flat cache. Though this will also lost some access performance, since the bit rotation is used to get the index of the cache array, and this could be ingored for memory I/O accessing. Signed-off-by: Xiubo Li Signed-off-by: Mark Brown