kernel/drivers/base/regmap, branch linux-6.5.y

regmap: Ensure range selector registers are updated after cache sync

2023-11-28T17:15:02Z

commit 0ec7731655de196bc1e4af99e495b38778109d22 upstream. When we sync the register cache we do so with the cache bypassed in order to avoid overhead from writing the synced values back into the cache. If the regmap has ranges and the selector register for those ranges is in a register which is cached this has the unfortunate side effect of meaning that the physical and cached copies of the selector register can be out of sync after a cache sync. The cache will have whatever the selector was when the sync started and the hardware will have the selector for the register that was synced last. Fix this by rewriting all cached selector registers after every sync, ensuring that the hardware and cache have the same content. This will result in extra writes that wouldn't otherwise be needed but is simple so hopefully robust. We don't read from the hardware since not all devices have physical read support. Given that nobody noticed this until now it is likely that we are rarely if ever hitting this case. Reported-by: Hector Martin Cc: stable@vger.kernel.org Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20231026-regmap-fix-selector-sync-v1-1-633ded82770d@kernel.org Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

regmap: prevent noinc writes from clobbering cache

2023-11-20T10:57:21Z

[ Upstream commit 984a4afdc87a1fc226fd657b1cd8255c13d3fc1a ] Currently, noinc writes are cached as if they were standard incrementing writes, overwriting unrelated register values in the cache. Instead, we want to cache the last value written to the register, as is done in the accelerated noinc handler (regmap_noinc_readwrite). Fixes: cdf6b11daa77 ("regmap: Add regmap_noinc_write API") Signed-off-by: Ben Wolsieffer Link: https://lore.kernel.org/r/20231101142926.2722603-2-ben.wolsieffer@hefring.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regmap: debugfs: Fix a erroneous check after snprintf()

2023-11-20T10:56:54Z

[ Upstream commit d3601857e14de6369f00ae19564f1d817d175d19 ] This error handling looks really strange. Check if the string has been truncated instead. Fixes: f0c2319f9f19 ("regmap: Expose the driver name in debugfs") Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/8595de2462c490561f70020a6d11f4d6b652b468.1693857825.git.christophe.jaillet@wanadoo.fr Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regmap: fix NULL deref on lookup

2023-10-25T10:16:10Z

commit c6df843348d6b71ea986266c12831cb60c2cf325 upstream. Not all regmaps have a name so make sure to check for that to avoid dereferencing a NULL pointer when dev_get_regmap() is used to lookup a named regmap. Fixes: e84861fec32d ("regmap: dev_get_regmap_match(): fix string comparison") Cc: stable@vger.kernel.org # 5.8 Cc: Marc Kleine-Budde Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20231006082104.16707-1-johan+linaro@kernel.org Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

regmap: rbtree: Fix wrong register marked as in-cache when creating new node

2023-10-10T20:03:00Z

[ Upstream commit 7a795ac8d49e2433e1b97caf5e99129daf8e1b08 ] 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 Signed-off-by: Sasha Levin

regmap: rbtree: Use alloc_flags for memory allocations

2023-09-13T07:53:02Z

[ Upstream commit 0c8b0bf42c8cef56f7cd9cd876fbb7ece9217064 ] 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 Signed-off-by: Sasha Levin

regmap: maple: Use alloc_flags for memory allocations

2023-09-13T07:53:02Z

[ Upstream commit b0393e1fe40e962574613a5cdc4a470d6c1de023 ] 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 Signed-off-by: Sasha Levin

regmap: Disable locking for RBTREE and MAPLE unit tests

2023-07-20T12:57:01Z

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

2023-07-19T11:58:42Z

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: Account for register length in SMBus I/O limits

2023-07-17T05:15:15Z

The SMBus I2C buses have limits on the size of transfers they can do but do not factor in the register length meaning we may try to do a transfer longer than our length limit, the core will not take care of this. Future changes will factor this out into the core but there are a number of users that assume current behaviour so let's just do something conservative here. This does not take account padding bits but practically speaking these are very rarely if ever used on I2C buses given that they generally run slowly enough to mean there's no issue. Cc: stable@kernel.org Signed-off-by: Mark Brown Reviewed-by: Xu Yilun Link: https://lore.kernel.org/r/20230712-regmap-max-transfer-v1-2-80e2aed22e83@kernel.org Signed-off-by: Mark Brown