linux.git/drivers/base/regmap, branch v6.6-rc2

regmap: Fix the type used for a bitmap pointer

2023-07-23T22:40:30+00:00

Bitmaps should be defined as 'unsigned long', not 'long'.
Fix the type of 'cache_present' is the 'struct regcache_rbtree_node'.

Signed-off-by: Christophe JAILLET 
Link: https://lore.kernel.org/r/5600df5003d23da10efcfafbda97ca55776d0d29.1689960321.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Mark Brown

regmap: Merge up fixes from mainline

2023-07-23T22:34:06+00:00

There's several things here that will really help my CI.

regmap: Remove dynamic allocation warnings for rbtree and maple

2023-07-21T16:36:09+00:00

Thanks to Dan and Guenter's very prompt updates of the rbtree and maple
caches to support GPF_ATOMIC allocations and since the update shook out
a bunch of users at least some of whom have been suitably careful about
ensuring that the cache is prepoulated so there are no dynamic
allocations after init let's revert the warnings.

Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20230721-regmap-enable-kmalloc-v1-1-f78287e794d3@kernel.org

regmap: rbtree: Use alloc_flags for memory allocations

2023-07-21T16:30:50+00:00

The kunit tests discovered a sleeping in atomic bug.  The allocations
in the regcache-rbtree code should use the map->alloc_flags instead of
GFP_KERNEL.

[    5.005510] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
[    5.005960] in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 117, name: kunit_try_catch
[    5.006219] preempt_count: 1, expected: 0
[    5.006414] 1 lock held by kunit_try_catch/117:
[    5.006590]  #0: 833b9010 (regmap_kunit:86:(config)->lock){....}-{2:2}, at: regmap_lock_spinlock+0x14/0x1c
[    5.007493] irq event stamp: 162
[    5.007627] hardirqs last  enabled at (161): [<80786738>] crng_make_state+0x1a0/0x294
[    5.007871] hardirqs last disabled at (162): [<80c531ec>] _raw_spin_lock_irqsave+0x7c/0x80
[    5.008119] softirqs last  enabled at (0): [<801110ac>] copy_process+0x810/0x2138
[    5.008356] softirqs last disabled at (0): [<00000000>] 0x0
[    5.008688] CPU: 0 PID: 117 Comm: kunit_try_catch Tainted: G                 N 6.4.4-rc3-g0e8d2fdfb188 #1
[    5.009011] Hardware name: Generic DT based system
[    5.009277]  unwind_backtrace from show_stack+0x18/0x1c
[    5.009497]  show_stack from dump_stack_lvl+0x38/0x5c
[    5.009676]  dump_stack_lvl from __might_resched+0x188/0x2d0
[    5.009860]  __might_resched from __kmem_cache_alloc_node+0x1dc/0x25c
[    5.010061]  __kmem_cache_alloc_node from kmalloc_trace+0x30/0xc8
[    5.010254]  kmalloc_trace from regcache_rbtree_write+0x26c/0x468
[    5.010446]  regcache_rbtree_write from _regmap_write+0x88/0x140
[    5.010634]  _regmap_write from regmap_write+0x44/0x68
[    5.010803]  regmap_write from basic_read_write+0x8c/0x270
[    5.010980]  basic_read_write from kunit_try_run_case+0x48/0xa0

Fixes: 28644c809f44 ("regmap: Add the rbtree cache support")
Reported-by: Guenter Roeck 
Closes: https://lore.kernel.org/all/ee59d128-413c-48ad-a3aa-d9d350c80042@roeck-us.net/
Signed-off-by: Dan Carpenter 
Tested-by: Guenter Roeck 
Link: https://lore.kernel.org/r/58f12a07-5f4b-4a8f-ab84-0a42d1908cb9@moroto.mountain
Signed-off-by: Mark Brown

regmap: maple: Use alloc_flags for memory allocations

2023-07-20T19:37:39+00:00

REGCACHE_MAPLE needs to allocate memory for regmap operations.
This results in lockdep splats if used with fast_io since fast_io uses
spinlocks for locking.

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 167, name: kunit_try_catch
preempt_count: 1, expected: 0
1 lock held by kunit_try_catch/167:
 #0: 838e9c10 (regmap_kunit:86:(config)->lock){....}-{2:2}, at: regmap_lock_spinlock+0x14/0x1c
irq event stamp: 146
hardirqs last  enabled at (145): [<8078bfa8>] crng_make_state+0x1a0/0x294
hardirqs last disabled at (146): [<80c5f62c>] _raw_spin_lock_irqsave+0x7c/0x80
softirqs last  enabled at (0): [<80110cc4>] copy_process+0x810/0x216c
softirqs last disabled at (0): [<00000000>] 0x0
CPU: 0 PID: 167 Comm: kunit_try_catch Tainted: G                 N 6.5.0-rc1-00028-gc4be22597a36-dirty #6
Hardware name: Generic DT based system
 unwind_backtrace from show_stack+0x18/0x1c
 show_stack from dump_stack_lvl+0x38/0x5c
 dump_stack_lvl from __might_resched+0x188/0x2d0
 __might_resched from __kmem_cache_alloc_node+0x1f4/0x258
 __kmem_cache_alloc_node from __kmalloc+0x48/0x170
 __kmalloc from regcache_maple_write+0x194/0x248
 regcache_maple_write from _regmap_write+0x88/0x140
 _regmap_write from regmap_write+0x44/0x68
 regmap_write from basic_read_write+0x8c/0x27c
 basic_read_write from kunit_generic_run_threadfn_adapter+0x1c/0x28
 kunit_generic_run_threadfn_adapter from kthread+0xf8/0x120
 kthread from ret_from_fork+0x14/0x3c
Exception stack(0x881a5fb0 to 0x881a5ff8)
5fa0:                                     00000000 00000000 00000000 00000000
5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 00000000 00000000 00000000 00000013 00000000

Use map->alloc_flags instead of GFP_KERNEL for memory allocations to fix
the problem.

Fixes: f033c26de5a5 ("regmap: Add maple tree based register cache")
Cc: Dan Carpenter 
Signed-off-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20230720172021.2617326-1-linux@roeck-us.net
Signed-off-by: Mark Brown

regmap: Reject fast_io regmap configurations with RBTREE and MAPLE caches

2023-07-20T12:57:05+00:00

REGCACHE_RBTREE and REGCACHE_MAPLE dynamically allocate memory for regmap
operations. This is incompatible with spinlock based locking which is used
for fast_io operations. Reject affected configurations.

Signed-off-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20230720032848.1306349-2-linux@roeck-us.net
Signed-off-by: Mark Brown

regmap: Disable locking for RBTREE and MAPLE unit tests

2023-07-20T12:57:01+00:00

REGCACHE_RBTREE and REGCACHE_MAPLE dynamically allocate memory
for regmap operations. This is incompatible with spinlock based locking
which is used for fast_io operations. Disable locking for the associated
unit tests to avoid lockdep splashes.

Fixes: f033c26de5a5 ("regmap: Add maple tree based register cache")
Fixes: 2238959b6ad2 ("regmap: Add some basic kunit tests")
Signed-off-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20230720032848.1306349-1-linux@roeck-us.net
Signed-off-by: Mark Brown

regcache: Push async I/O request down into the rbtree cache

2023-07-19T11:58:42+00:00

Currently the regcache core unconditionally enables async I/O for all cache
types, causing problems for the maple tree cache which dynamically allocates
the buffers used to write registers to the device since async requires the
buffers to be kept around until the I/O has been completed.

This use of async I/O is mainly for the rbtree cache which stores data in
a format directly usable for regmap_raw_write(), though there is a special
case for single register writes which would also have allowed it to be used
with the flat cache. It is a bit of a landmine for other caches since it
implicitly converts sync operations to async, and with modern hardware it
is not clear that async I/O is actually a performance win as shown by the
performance work David Jander did with SPI. In multi core systems the cost
of managing concurrency ends up swamping the performance benefit and almost
all modern systems are multi core.

Address this by pushing the enablement of async I/O down into the rbtree
cache where it is actively used, avoiding surprises for other cache
implementations.

Reported-by: Charles Keepax 
Fixes: bfa0b38c1483 ("regmap: maple: Implement block sync for the maple tree cache")
Reviewed-by: Charles Keepax 
Tested-by: Charles Keepax 
Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20230719-regcache-async-rbtree-v1-1-b03d30cf1daf@kernel.org
Signed-off-by: Mark Brown

regmap: Provide test for regcache_reg_present()

2023-07-18T14:05:11+00:00

Provide a KUnit test for the newly added API.

Reviewed-by: Takashi Iwai 
Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20230717-regmap-cache-check-v1-2-73ef688afae3@kernel.org
Signed-off-by: Mark Brown

regmap: Let users check if a register is cached

2023-07-18T14:05:10+00:00

The HDA driver has a use case for checking if a register is cached which
it bodges in awkwardly and unclearly. Provide an API which allows it to
directly do what it's trying to do.

Reviewed-by: Takashi Iwai 
Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20230717-regmap-cache-check-v1-1-73ef688afae3@kernel.org
Signed-off-by: Mark Brown