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2024-03-07nvmem: core: Print error on wrong bits DT propertyMarkus Schneider-Pargmann
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>
2024-02-14nvmem: include bit index in cell sysfs file nameArnd Bergmann
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: 0331c611949f ("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>
2024-01-04nvmem: core: add nvmem_dev_size() helperRafał Miłecki
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>
2024-01-04nvmem: drop nvmem_layout_get_match_data()Rafał Miłecki
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>
2024-01-04nvmem: layouts: refactor .add_cells() callback argumentsRafał Miłecki
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>
2023-12-15nvmem: core: Expose cells through sysfsMiquel Raynal
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>
2023-12-15nvmem: core: Rework layouts to become regular devicesMiquel Raynal
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>
2023-12-15nvmem: Move and rename ->fixup_cell_info()Miquel Raynal
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>
2023-12-15nvmem: Simplify the ->add_cells() hookMiquel Raynal
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>
2023-12-15nvmem: Create a header for internal sharingMiquel Raynal
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>
2023-12-15nvmem: Move of_nvmem_layout_get_container() in another headerMiquel Raynal
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>
2023-12-07nvmem: Do not expect fixed layouts to grab a layout driverMiquel Raynal
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: 27f699e578b1 ("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>
2023-10-27Revert "nvmem: add new config option"Rafał Miłecki
This reverts commit 517f14d9cf3533d5ab4fded195ab6f80a92e378f. 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>
2023-10-21nvmem: add explicit config option to read old syntax fixed OF cellsRafał Miłecki
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>
2023-08-23nvmem: core: Notify when a new layout is registeredMiquel Raynal
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>
2023-08-23nvmem: core: Do not open-code existing functionsMiquel Raynal
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>
2023-08-23nvmem: core: Create all cells before adding the nvmem deviceMiquel Raynal
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>
2023-08-23nvmem: Explicitly include correct DT includesRob Herring
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>
2023-06-15nvmem: core: add support for fixed cells *layout*Rafał Miłecki
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>
2023-04-27Merge tag 'modules-6.4-rc1' of ↵Linus Torvalds
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 8b41fc4454e ("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 ...
2023-04-13nvmem: core: remove MODULE_LICENSE in non-modulesNick Alcock
Since commit 8b41fc4454e ("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>
2023-04-05nvmem: core: support specifying both: cell raw data & post read lengthsRafał Miłecki
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>
2023-04-05nvmem: core: provide own priv pointer in post process callbackMichael Walle
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>
2023-04-05nvmem: cell: drop global cell_post_processMichael Walle
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>
2023-04-05nvmem: core: allow to modify a cell before adding itMichael Walle
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>
2023-04-05nvmem: core: add per-cell post processingMichael Walle
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>
2023-04-05nvmem: core: request layout modules loadingMiquel Raynal
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>
2023-04-05nvmem: core: handle the absence of expected layoutsMiquel Raynal
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>
2023-04-05nvmem: core: introduce NVMEM layoutsMichael Walle
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>
2023-03-10nvmem: core: return -ENOENT if nvmem cell is not foundMichael Walle
Prior to commit 5d8e6e6c10a3 ("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: 5d8e6e6c10a3 ("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>
2023-02-06nvmem: core: use nvmem_add_one_cell() in nvmem_add_cells_from_of()Michael Walle
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>
2023-02-06nvmem: core: add nvmem_add_one_cell()Michael Walle
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>
2023-02-06nvmem: core: drop the removal of the cells in nvmem_add_cells()Michael Walle
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>
2023-02-06nvmem: core: add an index parameter to the cellMichael Walle
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>
2023-02-06nvmem: core: remove spurious white spaceRussell King (Oracle)
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>
2023-01-28nvmem: core: fix return valueRussell King (Oracle)
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: 560181d3ace6 ("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>
2023-01-28nvmem: core: fix cell removal on errorMichael Walle
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: fa72d847d68d7 ("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>
2023-01-28nvmem: core: fix device node refcountingMichael Walle
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: 69aba7948cbe ("nvmem: Add a simple NVMEM framework for consumers") Fixes: 7ae6478b304b ("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>
2023-01-28nvmem: core: fix registration vs use raceRussell King (Oracle)
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: eace75cfdcf7 ("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>
2023-01-28nvmem: core: fix cleanup after dev_set_name()Russell King (Oracle)
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: 5544e90c8126 ("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>
2023-01-28nvmem: core: remove nvmem_config wp_gpioRussell King (Oracle)
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>
2023-01-28nvmem: core: initialise nvmem->id earlyRussell King (Oracle)
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: f7d8d7dcd978 ("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>
2022-09-24nvmem: core: add error handling for dev_set_nameGaosheng Cui
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>
2022-09-24nvmem: core: Fix memleak in nvmem_register()Gaosheng Cui
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: de0534df9347 ("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>
2022-05-09nvmem: core: support passing DT node in cell infoRafał Miłecki
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>
2022-02-28Merge 5.17-rc6 into char-misc-nextGreg Kroah-Hartman
We need the char-misc fixes in here. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-21nvmem: core: Check input parameter for NULL in nvmem_unregister()Andy Shevchenko
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>
2022-02-21nvmem: core: Use devm_add_action_or_reset()Andy Shevchenko
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>
2022-02-21nvmem: core: Remove unused devm_nvmem_unregister()Andy Shevchenko
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>
2022-02-21nvmem: core: Fix a conflict between MTD and NVMEM on wp-gpios propertyChristophe Kerello
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 <christophe.kerello@foss.st.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20220220151432.16605-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>