| Message ID | 20231218133722.16150-1-zajec5@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/4] dt-bindings: nvmem: layouts: add U-Boot environment variables layout | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | warning | total: 0 errors, 1 warnings, 70 lines checked |
| robh/patch-applied | success | |
| robh/dt-meta-schema | fail | build log |
Hi Rafał, zajec5@gmail.com wrote on Mon, 18 Dec 2023 14:37:21 +0100: > From: Rafał Miłecki <rafal@milecki.pl> > > 1. Use nvmem_dev_size() and nvmem_device_read() to make this driver less > mtd dependent > 2. Use nvmem_add_one_cell() to simplify adding NVMEM cells > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Thanks, Miquèl
Hi Rafał, zajec5@gmail.com wrote on Mon, 18 Dec 2023 14:37:20 +0100: > From: Rafał Miłecki <rafal@milecki.pl> > > 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). Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Thanks, Miquèl
Hi Rafał, zajec5@gmail.com wrote on Mon, 18 Dec 2023 14:37:22 +0100: > From: Rafał Miłecki <rafal@milecki.pl> > > This patch moves all generic (NVMEM devices independent) code from NVMEM > device driver to NVMEM layout driver. Then it adds a simple NVMEM layout > code on top of it. > > Thanks to proper layout it's possible to support U-Boot env data stored > on any kind of NVMEM device. > > For backward compatibility with old DT bindings we need to keep old > NVMEM device driver functional. To avoid code duplication a parsing > function is exported and reused in it. > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > --- I have a couple of comments about the original driver which gets copy-pasted in the new layout driver, maybe you could clean these (the memory leak should be fixed before the migration so it can be backported easily, the others are just style so it can be done after, I don't mind). ... > +int u_boot_env_parse(struct device *dev, struct nvmem_device *nvmem, > + enum u_boot_env_format format) > +{ > + size_t crc32_data_offset; > + size_t crc32_data_len; > + size_t crc32_offset; > + size_t data_offset; > + size_t data_len; > + size_t dev_size; > + uint32_t crc32; > + uint32_t calc; > + uint8_t *buf; > + int bytes; > + int err; > + > + dev_size = nvmem_dev_size(nvmem); > + > + buf = kcalloc(1, dev_size, GFP_KERNEL); Out of curiosity, why kcalloc(1,...) rather than kzalloc() ? > + if (!buf) { > + err = -ENOMEM; > + goto err_out; We could directly return ENOMEM here I guess. > + } > + > + bytes = nvmem_device_read(nvmem, 0, dev_size, buf); > + if (bytes < 0) > + return bytes; > + else if (bytes != dev_size) > + return -EIO; Don't we need to free buf in the above cases? > + switch (format) { > + case U_BOOT_FORMAT_SINGLE: > + crc32_offset = offsetof(struct u_boot_env_image_single, crc32); > + crc32_data_offset = offsetof(struct u_boot_env_image_single, data); > + data_offset = offsetof(struct u_boot_env_image_single, data); > + break; > + case U_BOOT_FORMAT_REDUNDANT: > + crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32); > + crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data); > + data_offset = offsetof(struct u_boot_env_image_redundant, data); > + break; > + case U_BOOT_FORMAT_BROADCOM: > + crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32); > + crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data); > + data_offset = offsetof(struct u_boot_env_image_broadcom, data); > + break; > + } > + crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset)); Looks a bit convoluted, any chances we can use intermediate variables to help decipher this? > + crc32_data_len = dev_size - crc32_data_offset; > + data_len = dev_size - data_offset; > + > + calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L; > + if (calc != crc32) { > + dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32); > + err = -EINVAL; > + goto err_kfree; > + } > + > + buf[dev_size - 1] = '\0'; > + err = u_boot_env_parse_cells(dev, nvmem, buf, data_offset, data_len); > + if (err) > + dev_err(dev, "Failed to add cells: %d\n", err); Please drop this error message, the only reason for which the function call would fail is apparently an ENOMEM case. > + > +err_kfree: > + kfree(buf); > +err_out: > + return err; > +} > +EXPORT_SYMBOL_GPL(u_boot_env_parse); > + > +static int u_boot_env_add_cells(struct device *dev, struct nvmem_device *nvmem) > +{ > + const struct of_device_id *match; > + struct device_node *layout_np; > + enum u_boot_env_format format; > + > + layout_np = of_nvmem_layout_get_container(nvmem); > + if (!layout_np) > + return -ENOENT; > + > + match = of_match_node(u_boot_env_of_match_table, layout_np); > + if (!match) > + return -ENOENT; > + > + format = (uintptr_t)match->data; In the core there is currently an unused helper called nvmem_layout_get_match_data() which does that. I think the original intent of this function was to be used in this driver, so depending on your preference, can you please either use it or remove it? > + > + of_node_put(layout_np); > + > + return u_boot_env_parse(dev, nvmem, format); > +} Thanks, Miquèl
On Mon, 18 Dec 2023 14:37:19 +0100, Rafał Miłecki wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > U-Boot env data is a way of storing firmware variables. It's a format > that can be used of top of various storage devices. Its binding should > be an NVMEM layout instead of a standalone device. > > This patch adds layout binding which allows using it on top of MTD NVMEM > device as well as any other. At the same time it deprecates the old > combined binding. > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > --- > .../bindings/nvmem/layouts/u-boot,env.yaml | 55 +++++++++++++++++++ > .../devicetree/bindings/nvmem/u-boot,env.yaml | 6 ++ > 2 files changed, 61 insertions(+) > create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml > My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check' on your patch (DT_CHECKER_FLAGS is new in v5.13): yamllint warnings/errors: dtschema/dtc warnings/errors: /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/nvmem/u-boot,env.example.dtb: partition@40000: 'ethaddr', 'reg' do not match any of the regexes: 'pinctrl-[0-9]+' from schema $id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml# /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/nvmem/u-boot,env.example.dtb: partition-u-boot-env: 'ethaddr' does not match any of the regexes: 'pinctrl-[0-9]+' from schema $id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml# doc reference errors (make refcheckdocs): See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20231218133722.16150-1-zajec5@gmail.com The base for the series is generally the latest rc1. A different dependency should be noted in *this* patch. If you already ran 'make dt_binding_check' and didn't see the above error(s), then make sure 'yamllint' is installed and dt-schema is up to date: pip3 install dtschema --upgrade Please check and re-submit after running the above command yourself. Note that DT_SCHEMA_FILES can be set to your schema file to speed up checking your schema. However, it must be unset to test all examples with your schema.
On 18.12.2023 15:21, Miquel Raynal wrote: > Hi Rafał, > > zajec5@gmail.com wrote on Mon, 18 Dec 2023 14:37:22 +0100: > >> From: Rafał Miłecki <rafal@milecki.pl> >> >> This patch moves all generic (NVMEM devices independent) code from NVMEM >> device driver to NVMEM layout driver. Then it adds a simple NVMEM layout >> code on top of it. >> >> Thanks to proper layout it's possible to support U-Boot env data stored >> on any kind of NVMEM device. >> >> For backward compatibility with old DT bindings we need to keep old >> NVMEM device driver functional. To avoid code duplication a parsing >> function is exported and reused in it. >> >> Signed-off-by: Rafał Miłecki <rafal@milecki.pl> >> --- > > I have a couple of comments about the original driver which gets > copy-pasted in the new layout driver, maybe you could clean these > (the memory leak should be fixed before the migration so it can be > backported easily, the others are just style so it can be done after, I > don't mind). > > ... > >> +int u_boot_env_parse(struct device *dev, struct nvmem_device *nvmem, >> + enum u_boot_env_format format) >> +{ >> + size_t crc32_data_offset; >> + size_t crc32_data_len; >> + size_t crc32_offset; >> + size_t data_offset; >> + size_t data_len; >> + size_t dev_size; >> + uint32_t crc32; >> + uint32_t calc; >> + uint8_t *buf; >> + int bytes; >> + int err; >> + >> + dev_size = nvmem_dev_size(nvmem); >> + >> + buf = kcalloc(1, dev_size, GFP_KERNEL); > > Out of curiosity, why kcalloc(1,...) rather than kzalloc() ? I used kcalloc() initially as I didn't need buffer to be zeroed. I see that memory-allocation.rst however says: > And, to be on the safe side it's best to use routines that set memory to zero, like kzalloc(). It's probably close to zero cost to zero that buffer so it could be kzalloc(). >> + if (!buf) { >> + err = -ENOMEM; >> + goto err_out; > > We could directly return ENOMEM here I guess. > >> + } >> + >> + bytes = nvmem_device_read(nvmem, 0, dev_size, buf); >> + if (bytes < 0) >> + return bytes; >> + else if (bytes != dev_size) >> + return -EIO; > > Don't we need to free buf in the above cases? > >> + switch (format) { >> + case U_BOOT_FORMAT_SINGLE: >> + crc32_offset = offsetof(struct u_boot_env_image_single, crc32); >> + crc32_data_offset = offsetof(struct u_boot_env_image_single, data); >> + data_offset = offsetof(struct u_boot_env_image_single, data); >> + break; >> + case U_BOOT_FORMAT_REDUNDANT: >> + crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32); >> + crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data); >> + data_offset = offsetof(struct u_boot_env_image_redundant, data); >> + break; >> + case U_BOOT_FORMAT_BROADCOM: >> + crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32); >> + crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data); >> + data_offset = offsetof(struct u_boot_env_image_broadcom, data); >> + break; >> + } >> + crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset)); > > Looks a bit convoluted, any chances we can use intermediate variables > to help decipher this? > >> + crc32_data_len = dev_size - crc32_data_offset; >> + data_len = dev_size - data_offset; >> + >> + calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L; >> + if (calc != crc32) { >> + dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32); >> + err = -EINVAL; >> + goto err_kfree; >> + } >> + >> + buf[dev_size - 1] = '\0'; >> + err = u_boot_env_parse_cells(dev, nvmem, buf, data_offset, data_len); >> + if (err) >> + dev_err(dev, "Failed to add cells: %d\n", err); > > Please drop this error message, the only reason for which the function > call would fail is apparently an ENOMEM case. > >> + >> +err_kfree: >> + kfree(buf); >> +err_out: >> + return err; >> +} >> +EXPORT_SYMBOL_GPL(u_boot_env_parse); >> + >> +static int u_boot_env_add_cells(struct device *dev, struct nvmem_device *nvmem) >> +{ >> + const struct of_device_id *match; >> + struct device_node *layout_np; >> + enum u_boot_env_format format; >> + >> + layout_np = of_nvmem_layout_get_container(nvmem); >> + if (!layout_np) >> + return -ENOENT; >> + >> + match = of_match_node(u_boot_env_of_match_table, layout_np); >> + if (!match) >> + return -ENOENT; >> + >> + format = (uintptr_t)match->data; > > In the core there is currently an unused helper called > nvmem_layout_get_match_data() which does that. I think the original > intent of this function was to be used in this driver, so depending on > your preference, can you please either use it or remove it? The problem is that nvmem_layout_get_match_data() uses: layout->dev.driver It doesn't work with layouts driver (since refactoring?) as driver is NULL. That results in NULL pointer dereference when trying to reach of_match_table. That is why I used u_boot_env_of_match_table directly. If you know how to fix nvmem_layout_get_match_data() that would be great. Do we need driver_register() somewhere in NVMEM core? >> + >> + of_node_put(layout_np); >> + >> + return u_boot_env_parse(dev, nvmem, format); >> +} > > Thanks, > Miquèl
On 18.12.2023 15:48, Rob Herring wrote: > > On Mon, 18 Dec 2023 14:37:19 +0100, Rafał Miłecki wrote: >> From: Rafał Miłecki <rafal@milecki.pl> >> >> U-Boot env data is a way of storing firmware variables. It's a format >> that can be used of top of various storage devices. Its binding should >> be an NVMEM layout instead of a standalone device. >> >> This patch adds layout binding which allows using it on top of MTD NVMEM >> device as well as any other. At the same time it deprecates the old >> combined binding. >> >> Signed-off-by: Rafał Miłecki <rafal@milecki.pl> >> --- >> .../bindings/nvmem/layouts/u-boot,env.yaml | 55 +++++++++++++++++++ >> .../devicetree/bindings/nvmem/u-boot,env.yaml | 6 ++ >> 2 files changed, 61 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml >> > > My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check' > on your patch (DT_CHECKER_FLAGS is new in v5.13): > > yamllint warnings/errors: > > dtschema/dtc warnings/errors: > /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/nvmem/u-boot,env.example.dtb: partition@40000: 'ethaddr', 'reg' do not match any of the regexes: 'pinctrl-[0-9]+' > from schema $id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml# > /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/nvmem/u-boot,env.example.dtb: partition-u-boot-env: 'ethaddr' does not match any of the regexes: 'pinctrl-[0-9]+' > from schema $id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml# I checked my binding independently using using dt_binding_check and missed that. I'm not aware of any way of limiting possibility of applying binding to specific cases (like "nvmem-layout" node) so I guess I'll just have to avoid duplicated "u-boot,env" compatible string. > doc reference errors (make refcheckdocs): > > See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20231218133722.16150-1-zajec5@gmail.com > > The base for the series is generally the latest rc1. A different dependency > should be noted in *this* patch. > > If you already ran 'make dt_binding_check' and didn't see the above > error(s), then make sure 'yamllint' is installed and dt-schema is up to > date: > > pip3 install dtschema --upgrade > > Please check and re-submit after running the above command yourself. Note > that DT_SCHEMA_FILES can be set to your schema file to speed up checking > your schema. However, it must be unset to test all examples with your schema. >
Hi Rafał, zajec5@gmail.com wrote on Mon, 18 Dec 2023 23:10:20 +0100: > On 18.12.2023 15:21, Miquel Raynal wrote: > > Hi Rafał, > > > > zajec5@gmail.com wrote on Mon, 18 Dec 2023 14:37:22 +0100: > > > >> From: Rafał Miłecki <rafal@milecki.pl> > >> > >> This patch moves all generic (NVMEM devices independent) code from NVMEM > >> device driver to NVMEM layout driver. Then it adds a simple NVMEM layout > >> code on top of it. > >> > >> Thanks to proper layout it's possible to support U-Boot env data stored > >> on any kind of NVMEM device. > >> > >> For backward compatibility with old DT bindings we need to keep old > >> NVMEM device driver functional. To avoid code duplication a parsing > >> function is exported and reused in it. > >> > >> Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > >> --- > > > > I have a couple of comments about the original driver which gets > > copy-pasted in the new layout driver, maybe you could clean these > > (the memory leak should be fixed before the migration so it can be > > backported easily, the others are just style so it can be done after, I > > don't mind). > > > > ... > > > >> +int u_boot_env_parse(struct device *dev, struct nvmem_device *nvmem, > >> + enum u_boot_env_format format) > >> +{ > >> + size_t crc32_data_offset; > >> + size_t crc32_data_len; > >> + size_t crc32_offset; > >> + size_t data_offset; > >> + size_t data_len; > >> + size_t dev_size; > >> + uint32_t crc32; > >> + uint32_t calc; > >> + uint8_t *buf; > >> + int bytes; > >> + int err; > >> + > >> + dev_size = nvmem_dev_size(nvmem); > >> + > >> + buf = kcalloc(1, dev_size, GFP_KERNEL); > > > > Out of curiosity, why kcalloc(1,...) rather than kzalloc() ? > > I used kcalloc() initially as I didn't need buffer to be zeroed. I think kcalloc() initializes the memory to zero. https://elixir.bootlin.com/linux/latest/source/include/linux/slab.h#L659 If you don't need it you can switch to kmalloc() instead, I don't mind, but kcalloc() is meant to be used with arrays, I don't see the point of using kcalloc() in this case. > > I see that memory-allocation.rst however says: > > And, to be on the safe side it's best to use routines that set memory to zero, like kzalloc(). > > It's probably close to zero cost to zero that buffer so it could be kzalloc(). > > > >> + if (!buf) { > >> + err = -ENOMEM; > >> + goto err_out; > > > > We could directly return ENOMEM here I guess. > > > >> + } > >> + > >> + bytes = nvmem_device_read(nvmem, 0, dev_size, buf); > >> + if (bytes < 0) > >> + return bytes; > >> + else if (bytes != dev_size) > >> + return -EIO; > > > > Don't we need to free buf in the above cases? > > > >> + switch (format) { > >> + case U_BOOT_FORMAT_SINGLE: > >> + crc32_offset = offsetof(struct u_boot_env_image_single, crc32); > >> + crc32_data_offset = offsetof(struct u_boot_env_image_single, data); > >> + data_offset = offsetof(struct u_boot_env_image_single, data); > >> + break; > >> + case U_BOOT_FORMAT_REDUNDANT: > >> + crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32); > >> + crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data); > >> + data_offset = offsetof(struct u_boot_env_image_redundant, data); > >> + break; > >> + case U_BOOT_FORMAT_BROADCOM: > >> + crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32); > >> + crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data); > >> + data_offset = offsetof(struct u_boot_env_image_broadcom, data); > >> + break; > >> + } > >> + crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset)); > > > > Looks a bit convoluted, any chances we can use intermediate variables > > to help decipher this? > > > >> + crc32_data_len = dev_size - crc32_data_offset; > >> + data_len = dev_size - data_offset; > >> + > >> + calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L; > >> + if (calc != crc32) { > >> + dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32); > >> + err = -EINVAL; > >> + goto err_kfree; > >> + } > >> + > >> + buf[dev_size - 1] = '\0'; > >> + err = u_boot_env_parse_cells(dev, nvmem, buf, data_offset, data_len); > >> + if (err) > >> + dev_err(dev, "Failed to add cells: %d\n", err); > > > > Please drop this error message, the only reason for which the function > > call would fail is apparently an ENOMEM case. > > > >> + > >> +err_kfree: > >> + kfree(buf); > >> +err_out: > >> + return err; > >> +} > >> +EXPORT_SYMBOL_GPL(u_boot_env_parse); > >> + > >> +static int u_boot_env_add_cells(struct device *dev, struct nvmem_device *nvmem) > >> +{ > >> + const struct of_device_id *match; > >> + struct device_node *layout_np; > >> + enum u_boot_env_format format; > >> + > >> + layout_np = of_nvmem_layout_get_container(nvmem); > >> + if (!layout_np) > >> + return -ENOENT; > >> + > >> + match = of_match_node(u_boot_env_of_match_table, layout_np); > >> + if (!match) > >> + return -ENOENT; > >> + > >> + format = (uintptr_t)match->data; > > > > In the core there is currently an unused helper called > > nvmem_layout_get_match_data() which does that. I think the original > > intent of this function was to be used in this driver, so depending on > > your preference, can you please either use it or remove it? > > The problem is that nvmem_layout_get_match_data() uses: > layout->dev.driver I'm surprised .driver is unset. Well anyway, please either fix the core helper and use it or drop the core helper, because we have no user for it otherwise? > It doesn't work with layouts driver (since refactoring?) as driver is > NULL. That results in NULL pointer dereference when trying to reach > of_match_table. > > That is why I used u_boot_env_of_match_table directly. > > If you know how to fix nvmem_layout_get_match_data() that would be > great. Do we need driver_register() somewhere in NVMEM core? > Thanks, Miquèl
On 19.12.2023 08:55, Miquel Raynal wrote: > Hi Rafał, > > zajec5@gmail.com wrote on Mon, 18 Dec 2023 23:10:20 +0100: > >> On 18.12.2023 15:21, Miquel Raynal wrote: >>> Hi Rafał, >>> >>> zajec5@gmail.com wrote on Mon, 18 Dec 2023 14:37:22 +0100: >>> >>>> From: Rafał Miłecki <rafal@milecki.pl> >>>> >>>> This patch moves all generic (NVMEM devices independent) code from NVMEM >>>> device driver to NVMEM layout driver. Then it adds a simple NVMEM layout >>>> code on top of it. >>>> >>>> Thanks to proper layout it's possible to support U-Boot env data stored >>>> on any kind of NVMEM device. >>>> >>>> For backward compatibility with old DT bindings we need to keep old >>>> NVMEM device driver functional. To avoid code duplication a parsing >>>> function is exported and reused in it. >>>> >>>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl> >>>> --- >>> >>> I have a couple of comments about the original driver which gets >>> copy-pasted in the new layout driver, maybe you could clean these >>> (the memory leak should be fixed before the migration so it can be >>> backported easily, the others are just style so it can be done after, I >>> don't mind). >>> >>> ... >>> >>>> +int u_boot_env_parse(struct device *dev, struct nvmem_device *nvmem, >>>> + enum u_boot_env_format format) >>>> +{ >>>> + size_t crc32_data_offset; >>>> + size_t crc32_data_len; >>>> + size_t crc32_offset; >>>> + size_t data_offset; >>>> + size_t data_len; >>>> + size_t dev_size; >>>> + uint32_t crc32; >>>> + uint32_t calc; >>>> + uint8_t *buf; >>>> + int bytes; >>>> + int err; >>>> + >>>> + dev_size = nvmem_dev_size(nvmem); >>>> + >>>> + buf = kcalloc(1, dev_size, GFP_KERNEL); >>> >>> Out of curiosity, why kcalloc(1,...) rather than kzalloc() ? >> >> I used kcalloc() initially as I didn't need buffer to be zeroed. > > I think kcalloc() initializes the memory to zero. > https://elixir.bootlin.com/linux/latest/source/include/linux/slab.h#L659 > > If you don't need it you can switch to kmalloc() instead, I don't mind, > but kcalloc() is meant to be used with arrays, I don't see the point of > using kcalloc() in this case. > >> >> I see that memory-allocation.rst however says: >> > And, to be on the safe side it's best to use routines that set memory to zero, like kzalloc(). >> >> It's probably close to zero cost to zero that buffer so it could be kzalloc(). >> >> >>>> + if (!buf) { >>>> + err = -ENOMEM; >>>> + goto err_out; >>> >>> We could directly return ENOMEM here I guess. >>> >>>> + } >>>> + >>>> + bytes = nvmem_device_read(nvmem, 0, dev_size, buf); >>>> + if (bytes < 0) >>>> + return bytes; >>>> + else if (bytes != dev_size) >>>> + return -EIO; >>> >>> Don't we need to free buf in the above cases? >>> >>>> + switch (format) { >>>> + case U_BOOT_FORMAT_SINGLE: >>>> + crc32_offset = offsetof(struct u_boot_env_image_single, crc32); >>>> + crc32_data_offset = offsetof(struct u_boot_env_image_single, data); >>>> + data_offset = offsetof(struct u_boot_env_image_single, data); >>>> + break; >>>> + case U_BOOT_FORMAT_REDUNDANT: >>>> + crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32); >>>> + crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data); >>>> + data_offset = offsetof(struct u_boot_env_image_redundant, data); >>>> + break; >>>> + case U_BOOT_FORMAT_BROADCOM: >>>> + crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32); >>>> + crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data); >>>> + data_offset = offsetof(struct u_boot_env_image_broadcom, data); >>>> + break; >>>> + } >>>> + crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset)); >>> >>> Looks a bit convoluted, any chances we can use intermediate variables >>> to help decipher this? >>> >>>> + crc32_data_len = dev_size - crc32_data_offset; >>>> + data_len = dev_size - data_offset; >>>> + >>>> + calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L; >>>> + if (calc != crc32) { >>>> + dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32); >>>> + err = -EINVAL; >>>> + goto err_kfree; >>>> + } >>>> + >>>> + buf[dev_size - 1] = '\0'; >>>> + err = u_boot_env_parse_cells(dev, nvmem, buf, data_offset, data_len); >>>> + if (err) >>>> + dev_err(dev, "Failed to add cells: %d\n", err); >>> >>> Please drop this error message, the only reason for which the function >>> call would fail is apparently an ENOMEM case. >>> >>>> + >>>> +err_kfree: >>>> + kfree(buf); >>>> +err_out: >>>> + return err; >>>> +} >>>> +EXPORT_SYMBOL_GPL(u_boot_env_parse); >>>> + >>>> +static int u_boot_env_add_cells(struct device *dev, struct nvmem_device *nvmem) >>>> +{ >>>> + const struct of_device_id *match; >>>> + struct device_node *layout_np; >>>> + enum u_boot_env_format format; >>>> + >>>> + layout_np = of_nvmem_layout_get_container(nvmem); >>>> + if (!layout_np) >>>> + return -ENOENT; >>>> + >>>> + match = of_match_node(u_boot_env_of_match_table, layout_np); >>>> + if (!match) >>>> + return -ENOENT; >>>> + >>>> + format = (uintptr_t)match->data; >>> >>> In the core there is currently an unused helper called >>> nvmem_layout_get_match_data() which does that. I think the original >>> intent of this function was to be used in this driver, so depending on >>> your preference, can you please either use it or remove it? >> >> The problem is that nvmem_layout_get_match_data() uses: >> layout->dev.driver > > I'm surprised .driver is unset. Well anyway, please either fix the core > helper and use it or drop the core helper, because we have no user for > it otherwise? I believe it's because of a very minimalistic "nvmem_bus_type" bus implementation. From a quick look it seems that default expected FORWARD-trace is: driver_register() bus_add_driver() driver_attach() __driver_attach() driver_probe_device() __driver_probe_device() really_probe() It's really_probe() that seems to set dev->driver pointer. >> It doesn't work with layouts driver (since refactoring?) as driver is >> NULL. That results in NULL pointer dereference when trying to reach >> of_match_table. >> >> That is why I used u_boot_env_of_match_table directly. >> >> If you know how to fix nvmem_layout_get_match_data() that would be >> great. Do we need driver_register() somewhere in NVMEM core?
On 19.12.2023 10:55, Rafał Miłecki wrote: > On 19.12.2023 08:55, Miquel Raynal wrote: >> Hi Rafał, >> >> zajec5@gmail.com wrote on Mon, 18 Dec 2023 23:10:20 +0100: >> >>> On 18.12.2023 15:21, Miquel Raynal wrote: >>>> Hi Rafał, >>>> >>>> zajec5@gmail.com wrote on Mon, 18 Dec 2023 14:37:22 +0100: >>>>> From: Rafał Miłecki <rafal@milecki.pl> >>>>> >>>>> This patch moves all generic (NVMEM devices independent) code from NVMEM >>>>> device driver to NVMEM layout driver. Then it adds a simple NVMEM layout >>>>> code on top of it. >>>>> >>>>> Thanks to proper layout it's possible to support U-Boot env data stored >>>>> on any kind of NVMEM device. >>>>> >>>>> For backward compatibility with old DT bindings we need to keep old >>>>> NVMEM device driver functional. To avoid code duplication a parsing >>>>> function is exported and reused in it. >>>>> >>>>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl> >>>>> --- >>>> >>>> I have a couple of comments about the original driver which gets >>>> copy-pasted in the new layout driver, maybe you could clean these >>>> (the memory leak should be fixed before the migration so it can be >>>> backported easily, the others are just style so it can be done after, I >>>> don't mind). >>>> >>>> ... >>>>> +int u_boot_env_parse(struct device *dev, struct nvmem_device *nvmem, >>>>> + enum u_boot_env_format format) >>>>> +{ >>>>> + size_t crc32_data_offset; >>>>> + size_t crc32_data_len; >>>>> + size_t crc32_offset; >>>>> + size_t data_offset; >>>>> + size_t data_len; >>>>> + size_t dev_size; >>>>> + uint32_t crc32; >>>>> + uint32_t calc; >>>>> + uint8_t *buf; >>>>> + int bytes; >>>>> + int err; >>>>> + >>>>> + dev_size = nvmem_dev_size(nvmem); >>>>> + >>>>> + buf = kcalloc(1, dev_size, GFP_KERNEL); >>>> >>>> Out of curiosity, why kcalloc(1,...) rather than kzalloc() ? >>> >>> I used kcalloc() initially as I didn't need buffer to be zeroed. >> >> I think kcalloc() initializes the memory to zero. >> https://elixir.bootlin.com/linux/latest/source/include/linux/slab.h#L659 >> >> If you don't need it you can switch to kmalloc() instead, I don't mind, >> but kcalloc() is meant to be used with arrays, I don't see the point of >> using kcalloc() in this case. >> >>> >>> I see that memory-allocation.rst however says: >>> > And, to be on the safe side it's best to use routines that set memory to zero, like kzalloc(). >>> >>> It's probably close to zero cost to zero that buffer so it could be kzalloc(). >>> >>> >>>>> + if (!buf) { >>>>> + err = -ENOMEM; >>>>> + goto err_out; >>>> >>>> We could directly return ENOMEM here I guess. >>>>> + } >>>>> + >>>>> + bytes = nvmem_device_read(nvmem, 0, dev_size, buf); >>>>> + if (bytes < 0) >>>>> + return bytes; >>>>> + else if (bytes != dev_size) >>>>> + return -EIO; >>>> >>>> Don't we need to free buf in the above cases? >>>>> + switch (format) { >>>>> + case U_BOOT_FORMAT_SINGLE: >>>>> + crc32_offset = offsetof(struct u_boot_env_image_single, crc32); >>>>> + crc32_data_offset = offsetof(struct u_boot_env_image_single, data); >>>>> + data_offset = offsetof(struct u_boot_env_image_single, data); >>>>> + break; >>>>> + case U_BOOT_FORMAT_REDUNDANT: >>>>> + crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32); >>>>> + crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data); >>>>> + data_offset = offsetof(struct u_boot_env_image_redundant, data); >>>>> + break; >>>>> + case U_BOOT_FORMAT_BROADCOM: >>>>> + crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32); >>>>> + crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data); >>>>> + data_offset = offsetof(struct u_boot_env_image_broadcom, data); >>>>> + break; >>>>> + } >>>>> + crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset)); >>>> >>>> Looks a bit convoluted, any chances we can use intermediate variables >>>> to help decipher this? >>>>> + crc32_data_len = dev_size - crc32_data_offset; >>>>> + data_len = dev_size - data_offset; >>>>> + >>>>> + calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L; >>>>> + if (calc != crc32) { >>>>> + dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32); >>>>> + err = -EINVAL; >>>>> + goto err_kfree; >>>>> + } >>>>> + >>>>> + buf[dev_size - 1] = '\0'; >>>>> + err = u_boot_env_parse_cells(dev, nvmem, buf, data_offset, data_len); >>>>> + if (err) >>>>> + dev_err(dev, "Failed to add cells: %d\n", err); >>>> >>>> Please drop this error message, the only reason for which the function >>>> call would fail is apparently an ENOMEM case. >>>>> + >>>>> +err_kfree: >>>>> + kfree(buf); >>>>> +err_out: >>>>> + return err; >>>>> +} >>>>> +EXPORT_SYMBOL_GPL(u_boot_env_parse); >>>>> + >>>>> +static int u_boot_env_add_cells(struct device *dev, struct nvmem_device *nvmem) >>>>> +{ >>>>> + const struct of_device_id *match; >>>>> + struct device_node *layout_np; >>>>> + enum u_boot_env_format format; >>>>> + >>>>> + layout_np = of_nvmem_layout_get_container(nvmem); >>>>> + if (!layout_np) >>>>> + return -ENOENT; >>>>> + >>>>> + match = of_match_node(u_boot_env_of_match_table, layout_np); >>>>> + if (!match) >>>>> + return -ENOENT; >>>>> + >>>>> + format = (uintptr_t)match->data; >>>> >>>> In the core there is currently an unused helper called >>>> nvmem_layout_get_match_data() which does that. I think the original >>>> intent of this function was to be used in this driver, so depending on >>>> your preference, can you please either use it or remove it? >>> >>> The problem is that nvmem_layout_get_match_data() uses: >>> layout->dev.driver >> >> I'm surprised .driver is unset. Well anyway, please either fix the core >> helper and use it or drop the core helper, because we have no user for >> it otherwise? > > I believe it's because of a very minimalistic "nvmem_bus_type" bus > implementation. Scratch that, I was looking at "nvmem_bus_type" instead of "nvmem_layout_bus_type". I'll see if I can debug that. > From a quick look it seems that default expected FORWARD-trace is: > driver_register() > bus_add_driver() > driver_attach() > __driver_attach() > driver_probe_device() > __driver_probe_device() > really_probe() > > It's really_probe() that seems to set dev->driver pointer. > > >>> It doesn't work with layouts driver (since refactoring?) as driver is >>> NULL. That results in NULL pointer dereference when trying to reach >>> of_match_table. >>> >>> That is why I used u_boot_env_of_match_table directly. >>> >>> If you know how to fix nvmem_layout_get_match_data() that would be >>> great. Do we need driver_register() somewhere in NVMEM core? >
diff --git a/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml new file mode 100644 index 000000000000..3a7ec02b3535 --- /dev/null +++ b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml @@ -0,0 +1,55 @@ +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: NVMEM layout of U-Boot environment variables + +maintainers: + - Rafał Miłecki <rafal@milecki.pl> + +description: + U-Boot uses environment variables to store device parameters and + configuration. They may be used for booting process, setup or keeping end user + info. + + Data is stored using U-Boot specific formats (variant specific header and NUL + separated key-value pairs). + +properties: + compatible: + oneOf: + - description: A standalone env data block + const: u-boot,env + - description: Two redundant blocks with active one flagged + const: u-boot,env-redundant-bool + - description: Two redundant blocks with active having higher counter + const: u-boot,env-redundant-count + - description: Broadcom's variant with custom header + const: brcm,env + +additionalProperties: false + +examples: + - | + partitions { + compatible = "fixed-partitions"; + #address-cells = <1>; + #size-cells = <1>; + + partition@0 { + reg = <0x0 0x40000>; + label = "u-boot"; + read-only; + }; + + partition@40000 { + reg = <0x40000 0x10000>; + label = "u-boot-env"; + + nvmem-layout { + compatible = "u-boot,env"; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml index 68214b96f5c9..fd95e611322d 100644 --- a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml +++ b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml @@ -26,9 +26,15 @@ description: | Variables can be defined as NVMEM device subnodes. + Introduction of NVMEM layouts exposed a limitation of this binding design. + Description of NVMEM data content should be separated from NVMEM devices. + Since the introduction of U-Boot env data layout this binding is deprecated. + maintainers: - Rafał Miłecki <rafal@milecki.pl> +deprecated: true + properties: compatible: oneOf: