linux-stable.git/drivers/nvmem/core.c, branch v5.18.2

Merge 5.17-rc6 into char-misc-next

2022-02-28T06:30:32+00:00

We need the char-misc fixes in here.

Signed-off-by: Greg Kroah-Hartman

nvmem: core: Check input parameter for NULL in nvmem_unregister()

2022-02-21T17:00:29+00:00

nvmem_unregister() frees resources and standard pattern is to allow
caller to not care if it's NULL or not. This will reduce burden on
the callers to perform this check.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20220220151527.17216-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: core: Use devm_add_action_or_reset()

2022-02-21T17:00:29+00:00

Slightly simplify the devm_nvmem_register() by using the
devm_add_action_or_reset().

Signed-off-by: Andy Shevchenko 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20220220151527.17216-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: core: Remove unused devm_nvmem_unregister()

2022-02-21T17:00:29+00:00

There are no users and seems no will come of the devm_nvmem_unregister().
Remove the function and remove the unused devm_nvmem_match() along with it.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20220220151527.17216-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: core: Fix a conflict between MTD and NVMEM on wp-gpios property

2022-02-21T16:59:25+00:00

Wp-gpios property can be used on NVMEM nodes and the same property can
be also used on MTD NAND nodes. In case of the wp-gpios property is
defined at NAND level node, the GPIO management is done at NAND driver
level. Write protect is disabled when the driver is probed or resumed
and is enabled when the driver is released or suspended.

When no partitions are defined in the NAND DT node, then the NAND DT node
will be passed to NVMEM framework. If wp-gpios property is defined in
this node, the GPIO resource is taken twice and the NAND controller
driver fails to probe.

It would be possible to set config->wp_gpio at MTD level before calling
nvmem_register function but NVMEM framework will toggle this GPIO on
each write when this GPIO should only be controlled at NAND level driver
to ensure that the Write Protect has not been enabled.

A way to fix this conflict is to add a new boolean flag in nvmem_config
named ignore_wp. In case ignore_wp is set, the GPIO resource will
be managed by the provider.

Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Kerello 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20220220151432.16605-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: core: set size for sysfs bin file

2021-12-03T15:03:37+00:00

For some reason we never set the size for nvmem sysfs binary file.
Set this.

Reported-by: Gilles BULOZ 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20211130133909.6154-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

Merge 5.15-rc6 into char-misc-next

2021-10-18T07:29:27+00:00

We need the char/misc fixes in here for merging and testing.

Signed-off-by: Greg Kroah-Hartman

nvmem: core: add nvmem cell post processing callback

2021-10-13T13:33:17+00:00

Some NVMEM providers have certain nvmem cells encoded, which requires
post processing before actually using it.

For example mac-address is stored in either in ascii or delimited or reverse-order.

Having a post-process callback hook to provider drivers would enable them to
do this vendor specific post processing before nvmem consumers see it.

Tested-by: Joakim Zhang 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20211013131957.30271-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: core: rework nvmem cell instance creation

2021-10-13T13:33:17+00:00

In the existing design, we do not create a instance per nvmem cell consumer
but we directly refer cell from nvmem cell list that are added to provider.

However this design has some limitations when consumers want to assign name
or connection id the nvmem cell instance, ex: via "nvmem-cell-names" or
id in nvmem_cell_get(id).

Having a name associated with nvmem cell consumer instance will help
provider drivers in performing post processing of nvmem cell data if required
before data is seen by the consumers. This is pretty normal with some vendors
storing nvmem cells like mac-address in a vendor specific data layouts that
are not directly usable by the consumer drivers.

With this patch nvmem cell will be created dynamically during nvmem_cell_get
and destroyed in nvmem_cell_put, allowing consumers to associate name with
nvmem cell consumer instance.

With this patch a new struct nvmem_cell_entry replaces struct nvmem_cell
for storing nvmem cell information within the core.
This patch does not change nvmem-consumer interface based on nvmem_cell.

Tested-by: Joakim Zhang 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20211013131957.30271-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: Fix shift-out-of-bound (UBSAN) with byte size cells

2021-10-13T13:09:58+00:00

If a cell has 'nbits' equal to a multiple of BITS_PER_BYTE the logic

 *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0);

will become undefined behavior because nbits modulo BITS_PER_BYTE is 0, and we
subtract one from that making a large number that is then shifted more than the
number of bits that fit into an unsigned long.

UBSAN reports this problem:

 UBSAN: shift-out-of-bounds in drivers/nvmem/core.c:1386:8
 shift exponent 64 is too large for 64-bit type 'unsigned long'
 CPU: 6 PID: 7 Comm: kworker/u16:0 Not tainted 5.15.0-rc3+ #9
 Hardware name: Google Lazor (rev3+) with KB Backlight (DT)
 Workqueue: events_unbound deferred_probe_work_func
 Call trace:
  dump_backtrace+0x0/0x170
  show_stack+0x24/0x30
  dump_stack_lvl+0x64/0x7c
  dump_stack+0x18/0x38
  ubsan_epilogue+0x10/0x54
  __ubsan_handle_shift_out_of_bounds+0x180/0x194
  __nvmem_cell_read+0x1ec/0x21c
  nvmem_cell_read+0x58/0x94
  nvmem_cell_read_variable_common+0x4c/0xb0
  nvmem_cell_read_variable_le_u32+0x40/0x100
  a6xx_gpu_init+0x170/0x2f4
  adreno_bind+0x174/0x284
  component_bind_all+0xf0/0x264
  msm_drm_bind+0x1d8/0x7a0
  try_to_bring_up_master+0x164/0x1ac
  __component_add+0xbc/0x13c
  component_add+0x20/0x2c
  dp_display_probe+0x340/0x384
  platform_probe+0xc0/0x100
  really_probe+0x110/0x304
  __driver_probe_device+0xb8/0x120
  driver_probe_device+0x4c/0xfc
  __device_attach_driver+0xb0/0x128
  bus_for_each_drv+0x90/0xdc
  __device_attach+0xc8/0x174
  device_initial_probe+0x20/0x2c
  bus_probe_device+0x40/0xa4
  deferred_probe_work_func+0x7c/0xb8
  process_one_work+0x128/0x21c
  process_scheduled_works+0x40/0x54
  worker_thread+0x1ec/0x2a8
  kthread+0x138/0x158
  ret_from_fork+0x10/0x20

Fix it by making sure there are any bits to mask out.

Fixes: 69aba7948cbe ("nvmem: Add a simple NVMEM framework for consumers")
Cc: Douglas Anderson 
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Boyd 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20211013124511.18726-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman