kernel/linux.git/drivers/base/regmap/regcache-flat.c, branch v7.0-rc7

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

regmap: Add reg_default_cb callback for flat cache defaults

2026-01-27T12:46:10+00:00

Commit e062bdfdd6ad ("regmap: warn users about uninitialized flat cache") warns when REGCACHE_FLAT is used without full defaults. This causes false positives on hardware where many registers reset to zero but are not listed in reg_defaults, forcing drivers to maintain large tables just to silence the warning. Add a reg_default_cb() hook so drivers can supply defaults for registers not present in reg_defaults when populating REGCACHE_FLAT. This keeps the warning quiet for known zero-reset registers without bloating tables. Provide a generic regmap_default_zero_cb() helper for drivers that need zero defaults. The hook is only used for REGCACHE_FLAT; the core does not check readable/writeable access, so drivers must provide readable_reg/ writeable_reg callbacks and handle holes in the register map. Signed-off-by: Sheetal Link: https://patch.msgid.link/20260123095346.1258556-3-sheetal@nvidia.com Signed-off-by: Mark Brown

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