linux-toradex.git/drivers/base/regmap/regcache-rbtree.c, branch v6.16

regmap: cache: rbtree: use krealloc_array() to replace krealloc()

2024-12-02T00:31:16+00:00

Use krealloc_array() to replace krealloc() with multiplication.
krealloc_array() has multiply overflow check, which will be safer.

Signed-off-by: Andy Shevchenko 
Link: https://patch.msgid.link/20241121123439.4180167-1-andriy.shevchenko@linux.intel.com
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: rbtree: Fix wrong register marked as in-cache when creating new node

2023-09-22T15:54:00+00:00

When regcache_rbtree_write() creates a new rbtree_node it was passing the
wrong bit number to regcache_rbtree_set_register(). The bit number is the
offset __in number of registers__, but in the case of creating a new block
regcache_rbtree_write() was not dividing by the address stride to get the
number of registers.

Fix this by dividing by map->reg_stride.
Compare with regcache_rbtree_read() where the bit is checked.

This bug meant that the wrong register was marked as present. The register
that was written to the cache could not be read from the cache because it
was not marked as cached. But a nearby register could be marked as having
a cached value even if it was never written to the cache.

Signed-off-by: Richard Fitzgerald 
Fixes: 3f4ff561bc88 ("regmap: rbtree: Make cache_present bitmap per node")
Link: https://lore.kernel.org/r/20230922153711.28103-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown

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: 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

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: Fix possible double-free in regcache_rbtree_exit()

2021-10-12T10:48:43+00:00

In regcache_rbtree_insert_to_block(), when 'present' realloc failed,
the 'blk' which is supposed to assign to 'rbnode->block' will be freed,
so 'rbnode->block' points a freed memory, in the error handling path of
regcache_rbtree_init(), 'rbnode->block' will be freed again in
regcache_rbtree_exit(), KASAN will report double-free as follows:

BUG: KASAN: double-free or invalid-free in kfree+0xce/0x390
Call Trace:
 slab_free_freelist_hook+0x10d/0x240
 kfree+0xce/0x390
 regcache_rbtree_exit+0x15d/0x1a0
 regcache_rbtree_init+0x224/0x2c0
 regcache_init+0x88d/0x1310
 __regmap_init+0x3151/0x4a80
 __devm_regmap_init+0x7d/0x100
 madera_spi_probe+0x10f/0x333 [madera_spi]
 spi_probe+0x183/0x210
 really_probe+0x285/0xc30

To fix this, moving up the assignment of rbnode->block to immediately after
the reallocation has succeeded so that the data structure stays valid even
if the second reallocation fails.

Reported-by: Hulk Robot 
Fixes: 3f4ff561bc88b ("regmap: rbtree: Make cache_present bitmap per node")
Signed-off-by: Yang Yingliang 
Link: https://lore.kernel.org/r/20211012023735.1632786-1-yangyingliang@huawei.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

regmap: Remove attribute packed from struct 'regcache_rbtree_node'

2019-01-29T15:23:56+00:00

On one hand commit 28644c809f44 ("regmap: Add the rbtree cache support")
added 'regcache_rbtree_node' as packed structure, while on the other hand
commit e977145aeaad ("[RBTREE] Add explicit alignment to sizeof(long)
for struct rb_node.") declared struct 'rb_node' as aligned.

Solve the ambiguity of placing aligned structure in a packed one by
removing the packed attribute from struct. This seems to be the behavior
of gcc anyway.

This removes the following warning (W=1):

  drivers/base/regmap/regcache-rbtree.c:36:1: warning: alignment 1 of 'struct regcache_rbtree_node' is less than 4 [-Wpacked-not-aligned]

Cc: Dimitris Papastamos 
Cc: David Woodhouse 
Signed-off-by: Mathieu Malaterre 
Signed-off-by: Mark Brown