Commit Graph

171 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
8d8fc146dd nvmem: core: switch to use device_add_groups()
devm_device_add_groups() is being removed from the kernel, so move the
nvmem driver to use device_add_groups() instead.  The logic is
identical, when the device is removed the driver core will properly
clean up and remove the groups, and the memory used by the attribute
groups will be freed because it was created with dev_* calls, so this is
functionally identical overall.

Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240430084921.33387-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-03 07:26:38 +02:00
Markus Schneider-Pargmann
def3173d4f nvmem: core: Print error on wrong bits DT property
The algorithms in nvmem core are built with the constraint that
bit_offset < 8. If bit_offset is greater the results are wrong. Print an
error if the devicetree 'bits' property is outside of the valid range
and abort parsing.

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240224114516.86365-12-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-07 20:21:53 +00:00
Arnd Bergmann
e20f378d99 nvmem: include bit index in cell sysfs file name
Creating sysfs files for all Cells caused a boot failure for linux-6.8-rc1 on
Apple M1, which (in downstream dts files) has multiple nvmem cells that use the
same byte address. This causes the device probe to fail with

[    0.605336] sysfs: cannot create duplicate filename '/devices/platform/soc@200000000/2922bc000.efuse/apple_efuses_nvmem0/cells/efuse@a10'
[    0.605347] CPU: 7 PID: 1 Comm: swapper/0 Tainted: G S                 6.8.0-rc1-arnd-5+ #133
[    0.605355] Hardware name: Apple Mac Studio (M1 Ultra, 2022) (DT)
[    0.605362] Call trace:
[    0.605365]  show_stack+0x18/0x2c
[    0.605374]  dump_stack_lvl+0x60/0x80
[    0.605383]  dump_stack+0x18/0x24
[    0.605388]  sysfs_warn_dup+0x64/0x80
[    0.605395]  sysfs_add_bin_file_mode_ns+0xb0/0xd4
[    0.605402]  internal_create_group+0x268/0x404
[    0.605409]  sysfs_create_groups+0x38/0x94
[    0.605415]  devm_device_add_groups+0x50/0x94
[    0.605572]  nvmem_populate_sysfs_cells+0x180/0x1b0
[    0.605682]  nvmem_register+0x38c/0x470
[    0.605789]  devm_nvmem_register+0x1c/0x6c
[    0.605895]  apple_efuses_probe+0xe4/0x120
[    0.606000]  platform_probe+0xa8/0xd0

As far as I can tell, this is a problem for any device with multiple cells on
different bits of the same address. Avoid the issue by changing the file name
to include the first bit number.

Fixes: 0331c61194 ("nvmem: core: Expose cells through sysfs")
Link: https://github.com/AsahiLinux/linux/blob/bd0a1a7d4/arch/arm64/boot/dts/apple/t600x-dieX.dtsi#L156
Cc:  <regressions@lists.linux.dev>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Rafał Miłecki <rafal@milecki.pl>
Cc: Chen-Yu Tsai <wenst@chromium.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:  <asahi@lists.linux.dev>
Cc: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Eric Curtin <ecurtin@redhat.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20240209163454.98051-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-14 16:28:16 +01:00
Rafał Miłecki
33cf42e68e nvmem: core: add nvmem_dev_size() helper
This is required by layouts that need to read whole NVMEM content. It's
especially useful for NVMEM devices without hardcoded layout (like
U-Boot environment data block).

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231221173421.13737-2-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04 17:01:13 +01:00
Rafał Miłecki
43f60e3fb6 nvmem: drop nvmem_layout_get_match_data()
Thanks for layouts refactoring we now have "struct device" associated
with layout. Also its OF pointer points directly to the "nvmem-layout"
DT node.

All it takes to get match data is a generic of_device_get_match_data().

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231219120104.3422-2-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04 17:01:13 +01:00
Rafał Miłecki
401df0d4f4 nvmem: layouts: refactor .add_cells() callback arguments
Simply pass whole "struct nvmem_layout" instead of single variables.
There is nothing in "struct nvmem_layout" that we have to hide from
layout drivers. They also access it during .probe() and .remove().

Thanks to this change:

1. API gets more consistent
   All layouts drivers callbacks get the same argument

2. Layouts get correct device
   Before this change NVMEM core code was passing NVMEM device instead
   of layout device. That resulted in:
   * Confusing prints
   * Calling devm_*() helpers on wrong device
   * Helpers like of_device_get_match_data() dereferencing NULLs

3. It gets possible to get match data
   First of all nvmem_layout_get_match_data() requires passing "struct
   nvmem_layout" which .add_cells() callback didn't have before this. It
   doesn't matter much as it's rather useless now anyway (and will be
   dropped).
   What's more important however is that of_device_get_match_data() can
   be used now thanks to owning a proper device pointer.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231219120104.3422-1-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04 17:01:13 +01:00
Miquel Raynal
0331c61194 nvmem: core: Expose cells through sysfs
The binary content of nvmem devices is available to the user so in the
easiest cases, finding the content of a cell is rather easy as it is
just a matter of looking at a known and fixed offset. However, nvmem
layouts have been recently introduced to cope with more advanced
situations, where the offset and size of the cells is not known in
advance or is dynamic. When using layouts, more advanced parsers are
used by the kernel in order to give direct access to the content of each
cell, regardless of its position/size in the underlying
device. Unfortunately, these information are not accessible by users,
unless by fully re-implementing the parser logic in userland.

Let's expose the cells and their content through sysfs to avoid these
situations. Of course the relevant NVMEM sysfs Kconfig option must be
enabled for this support to be available.

Not all nvmem devices expose cells. Indeed, the .bin_attrs attribute
group member will be filled at runtime only when relevant and will
remain empty otherwise. In this case, as the cells attribute group will
be empty, it will not lead to any additional folder/file creation.

Exposed cells are read-only. There is, in practice, everything in the
core to support a write path, but as I don't see any need for that, I
prefer to keep the interface simple (and probably safer). The interface
is documented as being in the "testing" state which means we can later
add a write attribute if though relevant.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 13:30:08 +01:00
Miquel Raynal
fc29fd821d nvmem: core: Rework layouts to become regular devices
Current layout support was initially written without modules support in
mind. When the requirement for module support rose, the existing base
was improved to adopt modularization support, but kind of a design flaw
was introduced. With the existing implementation, when a storage device
registers into NVMEM, the core tries to hook a layout (if any) and
populates its cells immediately. This means, if the hardware description
expects a layout to be hooked up, but no driver was provided for that,
the storage medium will fail to probe and try later from
scratch. Even if we consider that the hardware description shall be
correct, we could still probe the storage device (especially if it
contains the rootfs).

One way to overcome this situation is to consider the layouts as
devices, and leverage the native notifier mechanism. When a new NVMEM
device is registered, we can populate its nvmem-layout child, if any,
and wait for the matching to be done in order to get the cells (the
waiting can be easily done with the NVMEM notifiers). If the layout
driver is compiled as a module, it should automatically be loaded. This
way, there is no strong order to enforce, any NVMEM device creation
or NVMEM layout driver insertion will be observed as a new event which
may lead to the creation of additional cells, without disturbing the
probes with costly (and sometimes endless) deferrals.

In order to achieve that goal we create a new bus for the nvmem-layouts
with minimal logic to match nvmem-layout devices with nvmem-layout
drivers. All this infrastructure code is created in the layouts.c file.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 13:30:07 +01:00
Miquel Raynal
1172460e71 nvmem: Move and rename ->fixup_cell_info()
This hook is meant to be used by any provider and instantiating a layout
just for this is useless. Let's instead move this hook to the nvmem
device and add it to the config structure to be easily shared by the
providers.

While at moving this hook, rename it ->fixup_dt_cell_info() to clarify
its main intended purpose.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 13:30:07 +01:00
Miquel Raynal
1b7c298a4e nvmem: Simplify the ->add_cells() hook
The layout entry is not used and will anyway be made useless by the new
layout bus infrastructure coming next, so drop it. While at it, clarify
the kdoc entry.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 13:30:07 +01:00
Miquel Raynal
ec9c08a1cb nvmem: Create a header for internal sharing
Before adding all the NVMEM layout bus infrastructure to the core, let's
move the main nvmem_device structure in an internal header, only
available to the core. This way all the additional code can be added in
a dedicated file in order to keep the current core file tidy.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 13:30:07 +01:00
Miquel Raynal
4a1a40233b nvmem: Move of_nvmem_layout_get_container() in another header
nvmem-consumer.h is included by consumer devices, extracting data from
NVMEM devices whereas nvmem-provider.h is included by devices providing
NVMEM content.

The only users of of_nvmem_layout_get_container() outside of the core
are layout drivers, so better move its prototype to nvmem-provider.h.

While we do so, we also move the kdoc associated with the function to
the header rather than the .c file.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 13:30:07 +01:00
Miquel Raynal
b7c1e53751 nvmem: Do not expect fixed layouts to grab a layout driver
Two series lived in parallel for some time, which led to this situation:
- The nvmem-layout container is used for dynamic layouts
- We now expect fixed layouts to also use the nvmem-layout container but
this does not require any additional driver, the support is built-in the
nvmem core.

Ensure we don't refuse to probe for wrong reasons.

Fixes: 27f699e578 ("nvmem: core: add support for fixed cells *layout*")
Cc: stable@vger.kernel.org
Reported-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

Link: https://lore.kernel.org/r/20231124193814.360552-1-miquel.raynal@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-07 11:19:32 +09:00
Rafał Miłecki
f4cf4e5db3 Revert "nvmem: add new config option"
This reverts commit 517f14d9cf.

Config option "no_of_node" is no longer needed since adding a more
explicit and targeted option "add_legacy_fixed_of_cells".

That "no_of_node" config option was needed *earlier* to help mtd's case.

DT nodes of MTD partitions (that are also NVMEM devices) may contain
subnodes. Those SHOULD NOT be treated as NVMEM fixed cells.

To prevent NVMEM core code from parsing subnodes a "no_of_node" option
was added (and set to true in mtd) to make for_each_child_of_node() in
NVMEM a no-op. That was a bit hacky because it was messing with
"of_node" pointer to achieve some side-effect.

With the introduction of "add_legacy_fixed_of_cells" config option
things got more explicit. MTD subsystem simply tells NVMEM when to look
for fixed cells and there is no need to hack "of_node" pointer anymore.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231023102759.31529-1-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-27 13:17:54 +02:00
Rafał Miłecki
2cc3b37f5b nvmem: add explicit config option to read old syntax fixed OF cells
Binding for fixed NVMEM cells defined directly as NVMEM device subnodes
has been deprecated. It has been replaced by the "fixed-layout" NVMEM
layout binding.

New syntax is meant to be clearer and should help avoiding imprecise
bindings.

NVMEM subsystem already supports the new binding. It should be a good
idea to limit support for old syntax to existing drivers that actually
support & use it (we can't break backward compatibility!). That way we
additionally encourage new bindings & drivers to ignore deprecated
binding.

It wasn't clear (to me) if rtc and w1 code actually uses old syntax
fixed cells. I enabled them to don't risk any breakage.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
[for meson-{efuse,mx-efuse}.c]
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
[for mtk-efuse.c, nvmem/core.c, nvmem-provider.h]
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[MT8192, MT8195 Chromebooks]
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[for microchip-otpc.c]
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
[SAMA7G5-EK]
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231020105545.216052-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-21 19:19:06 +02:00
Miquel Raynal
eb176cb461 nvmem: core: Notify when a new layout is registered
Tell listeners a new layout was introduced and is now available.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230823132744.350618-23-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-23 16:34:02 +02:00
Miquel Raynal
b97400912a nvmem: core: Do not open-code existing functions
Use of_nvmem_layout_get_container() instead of hardcoding it.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230823132744.350618-22-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-23 16:34:02 +02:00
Miquel Raynal
f4d1d17e1d nvmem: core: Create all cells before adding the nvmem device
Let's pack all the cells creation in one place, so they are all created
before we add the nvmem device.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230823132744.350618-20-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-23 16:34:02 +02:00
Rob Herring
9bf75da0e2 nvmem: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230823132744.350618-14-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-23 16:34:01 +02:00
Rafał Miłecki
27f699e578 nvmem: core: add support for fixed cells *layout*
This adds support for the "fixed-layout" NVMEM layout binding. It allows
defining NVMEM cells in a layout DT node named "nvmem-layout".

While NVMEM subsystem supports layout drivers it has been discussed that
"fixed-layout" may actually be supperted internally. It's because:
1. It's a very basic layout
2. It allows sharing code with legacy syntax parsing
3. It's safer for soc_device_match() due to -EPROBE_DEFER
4. This will make the syntax transition easier

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Message-ID: <20230611140330.154222-26-srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-15 13:42:18 +02:00
Linus Torvalds
b6a7828502 modules-6.4-rc1
The summary of the changes for this pull requests is:
 
  * Song Liu's new struct module_memory replacement
  * Nick Alcock's MODULE_LICENSE() removal for non-modules
  * My cleanups and enhancements to reduce the areas where we vmalloc
    module memory for duplicates, and the respective debug code which
    proves the remaining vmalloc pressure comes from userspace.
 
 Most of the changes have been in linux-next for quite some time except
 the minor fixes I made to check if a module was already loaded
 prior to allocating the final module memory with vmalloc and the
 respective debug code it introduces to help clarify the issue. Although
 the functional change is small it is rather safe as it can only *help*
 reduce vmalloc space for duplicates and is confirmed to fix a bootup
 issue with over 400 CPUs with KASAN enabled. I don't expect stable
 kernels to pick up that fix as the cleanups would have also had to have
 been picked up. Folks on larger CPU systems with modules will want to
 just upgrade if vmalloc space has been an issue on bootup.
 
 Given the size of this request, here's some more elaborate details
 on this pull request.
 
 The functional change change in this pull request is the very first
 patch from Song Liu which replaces the struct module_layout with a new
 struct module memory. The old data structure tried to put together all
 types of supported module memory types in one data structure, the new
 one abstracts the differences in memory types in a module to allow each
 one to provide their own set of details. This paves the way in the
 future so we can deal with them in a cleaner way. If you look at changes
 they also provide a nice cleanup of how we handle these different memory
 areas in a module. This change has been in linux-next since before the
 merge window opened for v6.3 so to provide more than a full kernel cycle
 of testing. It's a good thing as quite a bit of fixes have been found
 for it.
 
 Jason Baron then made dynamic debug a first class citizen module user by
 using module notifier callbacks to allocate / remove module specific
 dynamic debug information.
 
 Nick Alcock has done quite a bit of work cross-tree to remove module
 license tags from things which cannot possibly be module at my request
 so to:
 
   a) help him with his longer term tooling goals which require a
      deterministic evaluation if a piece a symbol code could ever be
      part of a module or not. But quite recently it is has been made
      clear that tooling is not the only one that would benefit.
      Disambiguating symbols also helps efforts such as live patching,
      kprobes and BPF, but for other reasons and R&D on this area
      is active with no clear solution in sight.
 
   b) help us inch closer to the now generally accepted long term goal
      of automating all the MODULE_LICENSE() tags from SPDX license tags
 
 In so far as a) is concerned, although module license tags are a no-op
 for non-modules, tools which would want create a mapping of possible
 modules can only rely on the module license tag after the commit
 8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin
 or tristate.conf").  Nick has been working on this *for years* and
 AFAICT I was the only one to suggest two alternatives to this approach
 for tooling. The complexity in one of my suggested approaches lies in
 that we'd need a possible-obj-m and a could-be-module which would check
 if the object being built is part of any kconfig build which could ever
 lead to it being part of a module, and if so define a new define
 -DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've
 suggested would be to have a tristate in kconfig imply the same new
 -DPOSSIBLE_MODULE as well but that means getting kconfig symbol names
 mapping to modules always, and I don't think that's the case today. I am
 not aware of Nick or anyone exploring either of these options. Quite
 recently Josh Poimboeuf has pointed out that live patching, kprobes and
 BPF would benefit from resolving some part of the disambiguation as
 well but for other reasons. The function granularity KASLR (fgkaslr)
 patches were mentioned but Joe Lawrence has clarified this effort has
 been dropped with no clear solution in sight [1].
 
 In the meantime removing module license tags from code which could never
 be modules is welcomed for both objectives mentioned above. Some
 developers have also welcomed these changes as it has helped clarify
 when a module was never possible and they forgot to clean this up,
 and so you'll see quite a bit of Nick's patches in other pull
 requests for this merge window. I just picked up the stragglers after
 rc3. LWN has good coverage on the motivation behind this work [2] and
 the typical cross-tree issues he ran into along the way. The only
 concrete blocker issue he ran into was that we should not remove the
 MODULE_LICENSE() tags from files which have no SPDX tags yet, even if
 they can never be modules. Nick ended up giving up on his efforts due
 to having to do this vetting and backlash he ran into from folks who
 really did *not understand* the core of the issue nor were providing
 any alternative / guidance. I've gone through his changes and dropped
 the patches which dropped the module license tags where an SPDX
 license tag was missing, it only consisted of 11 drivers.  To see
 if a pull request deals with a file which lacks SPDX tags you
 can just use:
 
   ./scripts/spdxcheck.py -f \
 	$(git diff --name-only commid-id | xargs echo)
 
 You'll see a core module file in this pull request for the above,
 but that's not related to his changes. WE just need to add the SPDX
 license tag for the kernel/module/kmod.c file in the future but
 it demonstrates the effectiveness of the script.
 
 Most of Nick's changes were spread out through different trees,
 and I just picked up the slack after rc3 for the last kernel was out.
 Those changes have been in linux-next for over two weeks.
 
 The cleanups, debug code I added and final fix I added for modules
 were motivated by David Hildenbrand's report of boot failing on
 a systems with over 400 CPUs when KASAN was enabled due to running
 out of virtual memory space. Although the functional change only
 consists of 3 lines in the patch "module: avoid allocation if module is
 already present and ready", proving that this was the best we can
 do on the modules side took quite a bit of effort and new debug code.
 
 The initial cleanups I did on the modules side of things has been
 in linux-next since around rc3 of the last kernel, the actual final
 fix for and debug code however have only been in linux-next for about a
 week or so but I think it is worth getting that code in for this merge
 window as it does help fix / prove / evaluate the issues reported
 with larger number of CPUs. Userspace is not yet fixed as it is taking
 a bit of time for folks to understand the crux of the issue and find a
 proper resolution. Worst come to worst, I have a kludge-of-concept [3]
 of how to make kernel_read*() calls for modules unique / converge them,
 but I'm currently inclined to just see if userspace can fix this
 instead.
 
 [0] https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/
 [1] https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com
 [2] https://lwn.net/Articles/927569/
 [3] https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCgAwFiEENnNq2KuOejlQLZofziMdCjCSiKcFAmRG4m0SHG1jZ3JvZkBr
 ZXJuZWwub3JnAAoJEM4jHQowkoinQ2oP/0xlvKwJg6Ey8fHZF0qv8VOskE80zoLF
 hMazU3xfqLA+1TQvouW1YBxt3jwS3t1Ehs+NrV+nY9Yzcm0MzRX/n3fASJVe7nRr
 oqWWQU+voYl5Pw1xsfdp6C8IXpBQorpYby3Vp0MAMoZyl2W2YrNo36NV488wM9KC
 jD4HF5Z6xpnPSZTRR7AgW9mo7FdAtxPeKJ76Bch7lH8U6omT7n36WqTw+5B1eAYU
 YTOvrjRs294oqmWE+LeebyiOOXhH/yEYx4JNQgCwPdxwnRiGJWKsk5va0hRApqF/
 WW8dIqdEnjsa84lCuxnmWgbcPK8cgmlO0rT0DyneACCldNlldCW1LJ0HOwLk9pea
 p3JFAsBL7TKue4Tos6I7/4rx1ufyBGGIigqw9/VX5g0Iif+3BhWnqKRfz+p9wiMa
 Fl7cU6u7yC68CHu1HBSisK16cYMCPeOnTSd89upHj8JU/t74O6k/ARvjrQ9qmNUt
 c5U+OY+WpNJ1nXQydhY/yIDhFdYg8SSpNuIO90r4L8/8jRQYXNG80FDd1UtvVDuy
 eq0r2yZ8C0XHSlOT9QHaua/tWV/aaKtyC/c0hDRrigfUrq8UOlGujMXbUnrmrWJI
 tLJLAc7ePWAAoZXGSHrt0U27l029GzLwRdKqJ6kkDANVnTeOdV+mmBg9zGh3/Mp6
 agiwdHUMVN7X
 =56WK
 -----END PGP SIGNATURE-----

Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull module updates from Luis Chamberlain:
 "The summary of the changes for this pull requests is:

   - Song Liu's new struct module_memory replacement

   - Nick Alcock's MODULE_LICENSE() removal for non-modules

   - My cleanups and enhancements to reduce the areas where we vmalloc
     module memory for duplicates, and the respective debug code which
     proves the remaining vmalloc pressure comes from userspace.

  Most of the changes have been in linux-next for quite some time except
  the minor fixes I made to check if a module was already loaded prior
  to allocating the final module memory with vmalloc and the respective
  debug code it introduces to help clarify the issue. Although the
  functional change is small it is rather safe as it can only *help*
  reduce vmalloc space for duplicates and is confirmed to fix a bootup
  issue with over 400 CPUs with KASAN enabled. I don't expect stable
  kernels to pick up that fix as the cleanups would have also had to
  have been picked up. Folks on larger CPU systems with modules will
  want to just upgrade if vmalloc space has been an issue on bootup.

  Given the size of this request, here's some more elaborate details:

  The functional change change in this pull request is the very first
  patch from Song Liu which replaces the 'struct module_layout' with a
  new 'struct module_memory'. The old data structure tried to put
  together all types of supported module memory types in one data
  structure, the new one abstracts the differences in memory types in a
  module to allow each one to provide their own set of details. This
  paves the way in the future so we can deal with them in a cleaner way.
  If you look at changes they also provide a nice cleanup of how we
  handle these different memory areas in a module. This change has been
  in linux-next since before the merge window opened for v6.3 so to
  provide more than a full kernel cycle of testing. It's a good thing as
  quite a bit of fixes have been found for it.

  Jason Baron then made dynamic debug a first class citizen module user
  by using module notifier callbacks to allocate / remove module
  specific dynamic debug information.

  Nick Alcock has done quite a bit of work cross-tree to remove module
  license tags from things which cannot possibly be module at my request
  so to:

   a) help him with his longer term tooling goals which require a
      deterministic evaluation if a piece a symbol code could ever be
      part of a module or not. But quite recently it is has been made
      clear that tooling is not the only one that would benefit.
      Disambiguating symbols also helps efforts such as live patching,
      kprobes and BPF, but for other reasons and R&D on this area is
      active with no clear solution in sight.

   b) help us inch closer to the now generally accepted long term goal
      of automating all the MODULE_LICENSE() tags from SPDX license tags

  In so far as a) is concerned, although module license tags are a no-op
  for non-modules, tools which would want create a mapping of possible
  modules can only rely on the module license tag after the commit
  8b41fc4454 ("kbuild: create modules.builtin without
  Makefile.modbuiltin or tristate.conf").

  Nick has been working on this *for years* and AFAICT I was the only
  one to suggest two alternatives to this approach for tooling. The
  complexity in one of my suggested approaches lies in that we'd need a
  possible-obj-m and a could-be-module which would check if the object
  being built is part of any kconfig build which could ever lead to it
  being part of a module, and if so define a new define
  -DPOSSIBLE_MODULE [0].

  A more obvious yet theoretical approach I've suggested would be to
  have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
  well but that means getting kconfig symbol names mapping to modules
  always, and I don't think that's the case today. I am not aware of
  Nick or anyone exploring either of these options. Quite recently Josh
  Poimboeuf has pointed out that live patching, kprobes and BPF would
  benefit from resolving some part of the disambiguation as well but for
  other reasons. The function granularity KASLR (fgkaslr) patches were
  mentioned but Joe Lawrence has clarified this effort has been dropped
  with no clear solution in sight [1].

  In the meantime removing module license tags from code which could
  never be modules is welcomed for both objectives mentioned above. Some
  developers have also welcomed these changes as it has helped clarify
  when a module was never possible and they forgot to clean this up, and
  so you'll see quite a bit of Nick's patches in other pull requests for
  this merge window. I just picked up the stragglers after rc3. LWN has
  good coverage on the motivation behind this work [2] and the typical
  cross-tree issues he ran into along the way. The only concrete blocker
  issue he ran into was that we should not remove the MODULE_LICENSE()
  tags from files which have no SPDX tags yet, even if they can never be
  modules. Nick ended up giving up on his efforts due to having to do
  this vetting and backlash he ran into from folks who really did *not
  understand* the core of the issue nor were providing any alternative /
  guidance. I've gone through his changes and dropped the patches which
  dropped the module license tags where an SPDX license tag was missing,
  it only consisted of 11 drivers. To see if a pull request deals with a
  file which lacks SPDX tags you can just use:

    ./scripts/spdxcheck.py -f \
	$(git diff --name-only commid-id | xargs echo)

  You'll see a core module file in this pull request for the above, but
  that's not related to his changes. WE just need to add the SPDX
  license tag for the kernel/module/kmod.c file in the future but it
  demonstrates the effectiveness of the script.

  Most of Nick's changes were spread out through different trees, and I
  just picked up the slack after rc3 for the last kernel was out. Those
  changes have been in linux-next for over two weeks.

  The cleanups, debug code I added and final fix I added for modules
  were motivated by David Hildenbrand's report of boot failing on a
  systems with over 400 CPUs when KASAN was enabled due to running out
  of virtual memory space. Although the functional change only consists
  of 3 lines in the patch "module: avoid allocation if module is already
  present and ready", proving that this was the best we can do on the
  modules side took quite a bit of effort and new debug code.

  The initial cleanups I did on the modules side of things has been in
  linux-next since around rc3 of the last kernel, the actual final fix
  for and debug code however have only been in linux-next for about a
  week or so but I think it is worth getting that code in for this merge
  window as it does help fix / prove / evaluate the issues reported with
  larger number of CPUs. Userspace is not yet fixed as it is taking a
  bit of time for folks to understand the crux of the issue and find a
  proper resolution. Worst come to worst, I have a kludge-of-concept [3]
  of how to make kernel_read*() calls for modules unique / converge
  them, but I'm currently inclined to just see if userspace can fix this
  instead"

Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0]
Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1]
Link: https://lwn.net/Articles/927569/ [2]
Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3]

* tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits)
  module: add debugging auto-load duplicate module support
  module: stats: fix invalid_mod_bytes typo
  module: remove use of uninitialized variable len
  module: fix building stats for 32-bit targets
  module: stats: include uapi/linux/module.h
  module: avoid allocation if module is already present and ready
  module: add debug stats to help identify memory pressure
  module: extract patient module check into helper
  modules/kmod: replace implementation with a semaphore
  Change DEFINE_SEMAPHORE() to take a number argument
  module: fix kmemleak annotations for non init ELF sections
  module: Ignore L0 and rename is_arm_mapping_symbol()
  module: Move is_arm_mapping_symbol() to module_symbol.h
  module: Sync code of is_arm_mapping_symbol()
  scripts/gdb: use mem instead of core_layout to get the module address
  interconnect: remove module-related code
  interconnect: remove MODULE_LICENSE in non-modules
  zswap: remove MODULE_LICENSE in non-modules
  zpool: remove MODULE_LICENSE in non-modules
  x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules
  ...
2023-04-27 16:36:55 -07:00
Nick Alcock
83bc3f3cd8 nvmem: core: remove MODULE_LICENSE in non-modules
Since commit 8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.

So remove it in the files in this commit, none of which can be built as
modules.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 13:13:52 -07:00
Rafał Miłecki
55d4980ce5 nvmem: core: support specifying both: cell raw data & post read lengths
Callback .read_post_process() is designed to modify raw cell content
before providing it to the consumer. So far we were dealing with
modifications that didn't affect cell size (length). In some cases
however cell content needs to be reformatted and resized.

It's required e.g. to provide properly formatted MAC address in case
it's stored in a non-binary format (e.g. using ASCII).

There were few discussions how to optimally handle that. Following
possible solutions were considered:
1. Allow .read_post_process() to realloc (resize) content buffer
2. Allow .read_post_process() to adjust (decrease) just buffer length
3. Register NVMEM cells using post-read sizes

The preferred solution was the last one. The problem is that simply
adjusting "bytes" in NVMEM providers would result in core code NOT
passing whole raw data to .read_post_process() callbacks. It means
callback functions couldn't do their job without somehow manually
reading original cell content on their own.

This patch deals with that by registering NVMEM cells with both lengths:
raw content one and post read one. It allows:
1. Core code to read whole raw cell content
2. Callbacks to return content they want

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-35-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 19:41:13 +02:00
Michael Walle
8a134fd9f9 nvmem: core: provide own priv pointer in post process callback
It doesn't make any more sense to have a opaque pointer set up by the
nvmem device. Usually, the layout isn't associated with a particular
nvmem device. Instead, let the caller who set the post process callback
provide the priv pointer.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-21-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 19:41:11 +02:00
Michael Walle
011e40a166 nvmem: cell: drop global cell_post_process
There are no users anymore for the global cell_post_process callback
anymore. New users should use proper nvmem layouts.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-20-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 19:41:11 +02:00
Michael Walle
de12c96915 nvmem: core: allow to modify a cell before adding it
Provide a way to modify a cell before it will get added. This is useful
to attach a custom post processing hook via a layout.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-18-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 19:41:11 +02:00
Michael Walle
345ec382cd nvmem: core: add per-cell post processing
Instead of relying on the name the consumer is using for the cell, like
it is done for the nvmem .cell_post_process configuration parameter,
provide a per-cell post processing hook. This can then be populated by
the NVMEM provider (or the NVMEM layout) when adding the cell.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-17-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 19:41:11 +02:00
Miquel Raynal
b1c37bec1c nvmem: core: request layout modules loading
When a storage device like an eeprom or an mtd device probes, it
registers an nvmem device if the nvmem subsystem has been enabled (bool
symbol). During nvmem registration, if the device is using layouts to
expose dynamic nvmem cells, the core will first try to get a reference
over the layout driver callbacks. In practice there is not relationship
that can be described between the storage driver and the nvmem
layout. So there is no way we can enforce both drivers will be built-in
or both will be modules. If the storage device driver is built-in but
the layout is built as a module, instead of badly failing with an
endless probe deferral loop, lets just make a modprobe call in case the
driver was made available in an initramfs with
of_device_node_request_module(), and offer a fully functional system to
the user.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-16-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 19:41:11 +02:00
Miquel Raynal
6468a6f451 nvmem: core: handle the absence of expected layouts
Make nvmem_layout_get() return -EPROBE_DEFER while the expected layout
is not available. This condition cannot be triggered today as nvmem
layout drivers are initialed as part of an early init call, but soon
these drivers will be converted into modules and be initialized with a
standard priority, so the unavailability of the drivers might become a
reality that must be taken care of.

Let's anticipate this by telling the caller the layout might not yet be
available. A probe deferral is requested in this case.

Please note this does not affect any nvmem device not using layouts,
because an early check against the "nvmem-layout" container presence
will return NULL in this case.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-15-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 19:41:11 +02:00
Michael Walle
266570f496 nvmem: core: introduce NVMEM layouts
NVMEM layouts are used to generate NVMEM cells during runtime. Think of
an EEPROM with a well-defined conent. For now, the content can be
described by a device tree or a board file. But this only works if the
offsets and lengths are static and don't change. One could also argue
that putting the layout of the EEPROM in the device tree is the wrong
place. Instead, the device tree should just have a specific compatible
string.

Right now there are two use cases:
 (1) The NVMEM cell needs special processing. E.g. if it only specifies
     a base MAC address offset and you need to add an offset, or it
     needs to parse a MAC from ASCII format or some proprietary format.
     (Post processing of cells is added in a later commit).
 (2) u-boot environment parsing. The cells don't have a particular
     offset but it needs parsing the content to determine the offsets
     and length.

Co-developed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-14-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 19:41:11 +02:00
Michael Walle
06be62083c nvmem: core: return -ENOENT if nvmem cell is not found
Prior to commit 5d8e6e6c10 ("nvmem: core: add an index parameter to
the cell") of_nvmem_cell_get() would return -ENOENT if the cell wasn't
found. Particularly, if of_property_match_string() returned -EINVAL,
that return code was passed as the index to of_parse_phandle(), which
then detected it as invalid and returned NULL. That led to an return
code of -ENOENT.

With the new code, the negative index will lead to an -EINVAL of
of_parse_phandle_with_optional_args() which pass straight to the
caller and break those who expect an -ENOENT.

Fix it by always returning -ENOENT.

Fixes: 5d8e6e6c10 ("nvmem: core: add an index parameter to the cell")
Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/2143916.GUh0CODmnK@steina-w/
Signed-off-by: Michael Walle <michael@walle.cc>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230310094845.139400-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 10:55:49 +01:00
Michael Walle
50014d6596 nvmem: core: use nvmem_add_one_cell() in nvmem_add_cells_from_of()
Convert nvmem_add_cells_from_of() to use the new nvmem_add_one_cell().
This will remove duplicate code and it will make it possible to add a
hook to a nvmem layout in between, which can change fields before the
cell is finally added.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-17-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06 19:06:59 +01:00
Michael Walle
2ded6830d3 nvmem: core: add nvmem_add_one_cell()
Add a new function to add exactly one cell. This will be used by the
nvmem layout drivers to add custom cells. In contrast to the
nvmem_add_cells(), this has the advantage that we don't have to assemble
a list of cells on runtime.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-16-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06 19:06:59 +01:00
Michael Walle
cc5bdd323d nvmem: core: drop the removal of the cells in nvmem_add_cells()
If nvmem_add_cells() fails, the whole nvmem_register() will fail
and the cells will then be removed anyway. This is a preparation
to introduce a nvmem_add_one_cell() which can then be used by
nvmem_add_cells().

This is then the same to what nvmem_add_cells_from_table() and
nvmem_add_cells_from_of() do.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-15-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06 19:06:59 +01:00
Michael Walle
5d8e6e6c10 nvmem: core: add an index parameter to the cell
Sometimes a cell can represend multiple values. For example, a base
ethernet address stored in the NVMEM can be expanded into multiple
discreet ones by adding an offset.

For this use case, introduce an index parameter which is then used to
distiguish between values. This parameter will then be passed to the
post process hook which can then use it to create different values
during reading.

At the moment, there is only support for the device tree path. You can
add the index to the phandle, e.g.

  &net {
          nvmem-cells = <&base_mac_address 2>;
          nvmem-cell-names = "mac-address";
  };

  &nvmem_provider {
          base_mac_address: base-mac-address@0 {
                  #nvmem-cell-cells = <1>;
                  reg = <0 6>;
          };
  };

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-13-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06 19:06:59 +01:00
Russell King (Oracle)
2e8dc541ae nvmem: core: remove spurious white space
Remove a spurious white space in for the ida_alloc() call.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-8-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06 19:06:58 +01:00
Russell King (Oracle)
0c4862b1c1 nvmem: core: fix return value
Dan Carpenter points out that the return code was not set in commit
60c8b4aebd8e ("nvmem: core: fix cleanup after dev_set_name()"), but
this is not the only issue - we also need to zero wp_gpio to prevent
gpiod_put() being called on an error value.

Fixes: 560181d3ac ("nvmem: core: fix cleanup after dev_set_name()")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230127104015.23839-10-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-28 14:39:11 +01:00
Michael Walle
db3546d58b nvmem: core: fix cell removal on error
nvmem_add_cells() could return an error after some cells are already
added to the provider. In this case, the added cells are not removed.
Remove any registered cells if nvmem_add_cells() fails.

Fixes: fa72d847d6 ("nvmem: check the return value of nvmem_add_cells()")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230127104015.23839-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-28 14:38:49 +01:00
Michael Walle
edcf2fb660 nvmem: core: fix device node refcounting
In of_nvmem_cell_get(), of_get_next_parent() is used on cell_np. This
will decrement the refcount on cell_np, but cell_np is still used later
in the code. Use of_get_parent() instead and of_node_put() in the
appropriate places.

Fixes: 69aba7948c ("nvmem: Add a simple NVMEM framework for consumers")
Fixes: 7ae6478b30 ("nvmem: core: rework nvmem cell instance creation")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230127104015.23839-8-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-28 14:38:44 +01:00
Russell King (Oracle)
ab3428cfd9 nvmem: core: fix registration vs use race
The i.MX6 CPU frequency driver sometimes fails to register at boot time
due to nvmem_cell_read_u32() sporadically returning -ENOENT.

This happens because there is a window where __nvmem_device_get() in
of_nvmem_cell_get() is able to return the nvmem device, but as cells
have been setup, nvmem_find_cell_entry_by_node() returns NULL.

The occurs because the nvmem core registration code violates one of the
fundamental principles of kernel programming: do not publish data
structures before their setup is complete.

Fix this by making nvmem core code conform with this principle.

Fixes: eace75cfdc ("nvmem: Add a simple NVMEM framework for nvmem providers")
Cc: stable@vger.kernel.org
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230127104015.23839-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-28 14:36:29 +01:00
Russell King (Oracle)
560181d3ac nvmem: core: fix cleanup after dev_set_name()
If dev_set_name() fails, we leak nvmem->wp_gpio as the cleanup does not
put this. While a minimal fix for this would be to add the gpiod_put()
call, we can do better if we split device_register(), and use the
tested nvmem_release() cleanup code by initialising the device early,
and putting the device.

This results in a slightly larger fix, but results in clear code.

Note: this patch depends on "nvmem: core: initialise nvmem->id early"
and "nvmem: core: remove nvmem_config wp_gpio".

Fixes: 5544e90c81 ("nvmem: core: add error handling for dev_set_name")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
[Srini: Fixed subject line and error code handing with wp_gpio while applying.]
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230127104015.23839-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-28 14:36:29 +01:00
Russell King (Oracle)
569653f022 nvmem: core: remove nvmem_config wp_gpio
No one provides wp_gpio, so let's remove it to avoid issues with
the nvmem core putting this gpio.

Cc: stable@vger.kernel.org
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230127104015.23839-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-28 14:36:29 +01:00
Russell King (Oracle)
3bd747c7ea nvmem: core: initialise nvmem->id early
The error path for wp_gpio attempts to free the IDA nvmem->id, but
this has yet to be assigned, so will always be zero - leaking the
ID allocated by ida_alloc(). Fix this by moving the initialisation
of nvmem->id earlier.

Fixes: f7d8d7dcd9 ("nvmem: fix memory leak in error path")
Cc: stable@vger.kernel.org
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230127104015.23839-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-28 14:36:28 +01:00
Gaosheng Cui
5544e90c81 nvmem: core: add error handling for dev_set_name
The type of return value of dev_set_name is int, which may return
wrong result, so we add error handling for it to reclaim memory
of nvmem resource, and return early when an error occurs.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220916122100.170016-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-24 14:54:38 +02:00
Gaosheng Cui
bd1244561f nvmem: core: Fix memleak in nvmem_register()
dev_set_name will alloc memory for nvmem->dev.kobj.name in
nvmem_register, when nvmem_validate_keepouts failed, nvmem's
memory will be freed and return, but nobody will free memory
for nvmem->dev.kobj.name, there will be memleak, so moving
nvmem_validate_keepouts() after device_register() and let
the device core deal with cleaning name in error cases.

Fixes: de0534df93 ("nvmem: core: fix error handling while validating keepout regions")
Cc: stable@vger.kernel.org
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220916120402.38753-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-24 14:52:19 +02:00
Rafał Miłecki
dbc2f62061 nvmem: core: support passing DT node in cell info
Some hardware may have NVMEM cells described in Device Tree using
individual nodes. Let drivers pass such nodes to the NVMEM subsystem so
they can be later used by NVMEM consumers.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220429162701.2222-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-09 15:44:21 +02:00
Greg Kroah-Hartman
085686fb84 Merge 5.17-rc6 into char-misc-next
We need the char-misc fixes in here.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-28 07:30:32 +01:00
Andy Shevchenko
8c751e0d9a nvmem: core: Check input parameter for NULL in nvmem_unregister()
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 <andriy.shevchenko@linux.intel.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220220151527.17216-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-21 18:00:29 +01:00
Andy Shevchenko
5825b2c676 nvmem: core: Use devm_add_action_or_reset()
Slightly simplify the devm_nvmem_register() by using the
devm_add_action_or_reset().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220220151527.17216-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-21 18:00:29 +01:00
Andy Shevchenko
190fae4685 nvmem: core: Remove unused devm_nvmem_unregister()
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 <andriy.shevchenko@linux.intel.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220220151527.17216-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-21 18:00:29 +01:00