| Message ID | 20231218133722.16150-4-zajec5@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/4] dt-bindings: nvmem: layouts: add U-Boot environment variables layout | expand |
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 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
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/MAINTAINERS b/MAINTAINERS index b589218605b4..1f7e6d74cd51 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22282,6 +22282,7 @@ U-BOOT ENVIRONMENT VARIABLES M: Rafał Miłecki <rafal@milecki.pl> S: Maintained F: Documentation/devicetree/bindings/nvmem/u-boot,env.yaml +F: drivers/nvmem/layouts/u-boot-env.c F: drivers/nvmem/u-boot-env.c UACCE ACCELERATOR FRAMEWORK diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig index 283134498fbc..d2c384f58028 100644 --- a/drivers/nvmem/Kconfig +++ b/drivers/nvmem/Kconfig @@ -363,8 +363,7 @@ config NVMEM_SUNXI_SID config NVMEM_U_BOOT_ENV tristate "U-Boot environment variables support" depends on OF && MTD - select CRC32 - select GENERIC_NET_UTILS + select NVMEM_LAYOUT_U_BOOT_ENV help U-Boot stores its setup as environment variables. This driver adds support for verifying & exporting such data. It also exposes variables diff --git a/drivers/nvmem/layouts/Kconfig b/drivers/nvmem/layouts/Kconfig index 9c6e672fc350..5e586dfebe47 100644 --- a/drivers/nvmem/layouts/Kconfig +++ b/drivers/nvmem/layouts/Kconfig @@ -26,6 +26,17 @@ config NVMEM_LAYOUT_ONIE_TLV If unsure, say N. +config NVMEM_LAYOUT_U_BOOT_ENV + tristate "U-Boot environment variables layout" + select CRC32 + select GENERIC_NET_UTILS + help + U-Boot stores its setup as environment variables. This driver adds + support for verifying & exporting such data. It also exposes variables + as NVMEM cells so they can be referenced by other drivers. + + If unsure, say N. + endmenu endif diff --git a/drivers/nvmem/layouts/Makefile b/drivers/nvmem/layouts/Makefile index 2974bd7d33ed..4940c9db0665 100644 --- a/drivers/nvmem/layouts/Makefile +++ b/drivers/nvmem/layouts/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_NVMEM_LAYOUT_SL28_VPD) += sl28vpd.o obj-$(CONFIG_NVMEM_LAYOUT_ONIE_TLV) += onie-tlv.o +obj-$(CONFIG_NVMEM_LAYOUT_U_BOOT_ENV) += u-boot-env.o diff --git a/drivers/nvmem/layouts/u-boot-env.c b/drivers/nvmem/layouts/u-boot-env.c new file mode 100644 index 000000000000..1787cfaf45f8 --- /dev/null +++ b/drivers/nvmem/layouts/u-boot-env.c @@ -0,0 +1,212 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022 - 2023 Rafał Miłecki <rafal@milecki.pl> + */ + +#include <linux/crc32.h> +#include <linux/etherdevice.h> +#include <linux/export.h> +#include <linux/if_ether.h> +#include <linux/nvmem-consumer.h> +#include <linux/nvmem-provider.h> +#include <linux/of.h> +#include <linux/slab.h> + +#include "u-boot-env.h" + +struct u_boot_env_image_single { + __le32 crc32; + uint8_t data[]; +} __packed; + +struct u_boot_env_image_redundant { + __le32 crc32; + u8 mark; + uint8_t data[]; +} __packed; + +struct u_boot_env_image_broadcom { + __le32 magic; + __le32 len; + __le32 crc32; + DECLARE_FLEX_ARRAY(uint8_t, data); +} __packed; + +static const struct of_device_id u_boot_env_of_match_table[] = { + { .compatible = "u-boot,env", .data = (void *)U_BOOT_FORMAT_SINGLE, }, + { .compatible = "u-boot,env-redundant-bool", .data = (void *)U_BOOT_FORMAT_REDUNDANT, }, + { .compatible = "u-boot,env-redundant-count", .data = (void *)U_BOOT_FORMAT_REDUNDANT, }, + { .compatible = "brcm,env", .data = (void *)U_BOOT_FORMAT_BROADCOM, }, + {}, +}; + +static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, int index, + unsigned int offset, void *buf, size_t bytes) +{ + u8 mac[ETH_ALEN]; + + if (bytes != 3 * ETH_ALEN - 1) + return -EINVAL; + + if (!mac_pton(buf, mac)) + return -EINVAL; + + if (index) + eth_addr_add(mac, index); + + ether_addr_copy(buf, mac); + + return 0; +} + +static int u_boot_env_parse_cells(struct device *dev, struct nvmem_device *nvmem, uint8_t *buf, + size_t data_offset, size_t data_len) +{ + char *data = buf + data_offset; + char *var, *value, *eq; + + for (var = data; + var < data + data_len && *var; + var = value + strlen(value) + 1) { + struct nvmem_cell_info info = {}; + + eq = strchr(var, '='); + if (!eq) + break; + *eq = '\0'; + value = eq + 1; + + info.name = devm_kstrdup(dev, var, GFP_KERNEL); + if (!info.name) + return -ENOMEM; + info.offset = data_offset + value - data; + info.bytes = strlen(value); + info.np = of_get_child_by_name(dev->of_node, info.name); + if (!strcmp(var, "ethaddr")) { + info.raw_len = strlen(value); + info.bytes = ETH_ALEN; + info.read_post_process = u_boot_env_read_post_process_ethaddr; + } + + nvmem_add_one_cell(nvmem, &info); + } + + return 0; +} + +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); + if (!buf) { + err = -ENOMEM; + goto err_out; + } + + bytes = nvmem_device_read(nvmem, 0, dev_size, buf); + if (bytes < 0) + return bytes; + else if (bytes != dev_size) + return -EIO; + + 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)); + 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); + +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; + + of_node_put(layout_np); + + return u_boot_env_parse(dev, nvmem, format); +} + +static int u_boot_env_probe(struct nvmem_layout *layout) +{ + layout->add_cells = u_boot_env_add_cells; + + return nvmem_layout_register(layout); +} + +static void u_boot_env_remove(struct nvmem_layout *layout) +{ + nvmem_layout_unregister(layout); +} + +static struct nvmem_layout_driver u_boot_env_layout = { + .driver = { + .owner = THIS_MODULE, + .name = "u-boot-env-layout", + .of_match_table = u_boot_env_of_match_table, + }, + .probe = u_boot_env_probe, + .remove = u_boot_env_remove, +}; +module_nvmem_layout_driver(u_boot_env_layout); + +MODULE_AUTHOR("Rafał Miłecki"); +MODULE_LICENSE("GPL"); +MODULE_DEVICE_TABLE(of, u_boot_env_of_match_table); diff --git a/drivers/nvmem/layouts/u-boot-env.h b/drivers/nvmem/layouts/u-boot-env.h new file mode 100644 index 000000000000..dd5f280ac047 --- /dev/null +++ b/drivers/nvmem/layouts/u-boot-env.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef _LINUX_NVMEM_LAYOUTS_U_BOOT_ENV_H +#define _LINUX_NVMEM_LAYOUTS_U_BOOT_ENV_H + +enum u_boot_env_format { + U_BOOT_FORMAT_SINGLE, + U_BOOT_FORMAT_REDUNDANT, + U_BOOT_FORMAT_BROADCOM, +}; + +int u_boot_env_parse(struct device *dev, struct nvmem_device *nvmem, + enum u_boot_env_format format); + +#endif /* ifndef _LINUX_NVMEM_LAYOUTS_U_BOOT_ENV_H */ diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/u-boot-env.c index ab8c9bf63d99..386b2b255c30 100644 --- a/drivers/nvmem/u-boot-env.c +++ b/drivers/nvmem/u-boot-env.c @@ -3,23 +3,15 @@ * Copyright (C) 2022 Rafał Miłecki <rafal@milecki.pl> */ -#include <linux/crc32.h> -#include <linux/etherdevice.h> -#include <linux/if_ether.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/mtd/mtd.h> -#include <linux/nvmem-consumer.h> #include <linux/nvmem-provider.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/slab.h> -enum u_boot_env_format { - U_BOOT_FORMAT_SINGLE, - U_BOOT_FORMAT_REDUNDANT, - U_BOOT_FORMAT_BROADCOM, -}; +#include "layouts/u-boot-env.h" struct u_boot_env { struct device *dev; @@ -29,24 +21,6 @@ struct u_boot_env { struct mtd_info *mtd; }; -struct u_boot_env_image_single { - __le32 crc32; - uint8_t data[]; -} __packed; - -struct u_boot_env_image_redundant { - __le32 crc32; - u8 mark; - uint8_t data[]; -} __packed; - -struct u_boot_env_image_broadcom { - __le32 magic; - __le32 len; - __le32 crc32; - DECLARE_FLEX_ARRAY(uint8_t, data); -} __packed; - static int u_boot_env_read(void *context, unsigned int offset, void *val, size_t bytes) { @@ -69,131 +43,6 @@ static int u_boot_env_read(void *context, unsigned int offset, void *val, return 0; } -static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, int index, - unsigned int offset, void *buf, size_t bytes) -{ - u8 mac[ETH_ALEN]; - - if (bytes != 3 * ETH_ALEN - 1) - return -EINVAL; - - if (!mac_pton(buf, mac)) - return -EINVAL; - - if (index) - eth_addr_add(mac, index); - - ether_addr_copy(buf, mac); - - return 0; -} - -static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf, - size_t data_offset, size_t data_len) -{ - struct nvmem_device *nvmem = priv->nvmem; - struct device *dev = priv->dev; - char *data = buf + data_offset; - char *var, *value, *eq; - - for (var = data; - var < data + data_len && *var; - var = value + strlen(value) + 1) { - struct nvmem_cell_info info = {}; - - eq = strchr(var, '='); - if (!eq) - break; - *eq = '\0'; - value = eq + 1; - - info.name = devm_kstrdup(dev, var, GFP_KERNEL); - if (!info.name) - return -ENOMEM; - info.offset = data_offset + value - data; - info.bytes = strlen(value); - info.np = of_get_child_by_name(dev->of_node, info.name); - if (!strcmp(var, "ethaddr")) { - info.raw_len = strlen(value); - info.bytes = ETH_ALEN; - info.read_post_process = u_boot_env_read_post_process_ethaddr; - } - - nvmem_add_one_cell(nvmem, &info); - } - - return 0; -} - -static int u_boot_env_parse(struct u_boot_env *priv) -{ - struct nvmem_device *nvmem = priv->nvmem; - struct device *dev = priv->dev; - 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); - if (!buf) { - err = -ENOMEM; - goto err_out; - } - - bytes = nvmem_device_read(nvmem, 0, dev_size, buf); - if (bytes < 0) - return bytes; - else if (bytes != dev_size) - return -EIO; - - switch (priv->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)); - 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_add_cells(priv, buf, data_offset, data_len); - if (err) - dev_err(dev, "Failed to add cells: %d\n", err); - -err_kfree: - kfree(buf); -err_out: - return err; -} - static int u_boot_env_probe(struct platform_device *pdev) { struct nvmem_config config = { @@ -225,7 +74,7 @@ static int u_boot_env_probe(struct platform_device *pdev) if (IS_ERR(priv->nvmem)) return PTR_ERR(priv->nvmem); - return u_boot_env_parse(priv); + return u_boot_env_parse(dev, priv->nvmem, priv->format); } static const struct of_device_id u_boot_env_of_match_table[] = {