[PATCH V2 1/5] dt-bindings: nvmem: layouts: add U-Boot environment variables layout

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 --- V2: Add "-layout" suffix to compatibles to avoid conflict
.../nvmem/layouts/u-boot,env-layout.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-layout.yaml
diff --git a/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env-layout.yaml new file mode 100644 index 000000000000..3b4d8f2a44e1 --- /dev/null +++ b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env-layout.yaml @@ -0,0 +1,55 @@ +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env-layout.yaml# +$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-layout + - description: Two redundant blocks with active one flagged + const: u-boot,env-redundant-bool-layout + - description: Two redundant blocks with active having higher counter + const: u-boot,env-redundant-count-layout + - description: Broadcom's variant with custom header + const: brcm,env-layout + +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-layout"; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml index 9c36afc7084b..6c2a3ca5f051 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:

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).
Signed-off-by: Rafał Miłecki rafal@milecki.pl Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com --- drivers/nvmem/core.c | 13 +++++++++++++ include/linux/nvmem-consumer.h | 1 + 2 files changed, 14 insertions(+)
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 4ed54076346d..980123fb4dde 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -2163,6 +2163,19 @@ const char *nvmem_dev_name(struct nvmem_device *nvmem) } EXPORT_SYMBOL_GPL(nvmem_dev_name);
+/** + * nvmem_dev_size() - Get the size of a given nvmem device. + * + * @nvmem: nvmem device. + * + * Return: size of the nvmem device. + */ +size_t nvmem_dev_size(struct nvmem_device *nvmem) +{ + return nvmem->size; +} +EXPORT_SYMBOL_GPL(nvmem_dev_size); + static int __init nvmem_init(void) { int ret; diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h index 2d306fa13b1a..34c0e58dfa26 100644 --- a/include/linux/nvmem-consumer.h +++ b/include/linux/nvmem-consumer.h @@ -81,6 +81,7 @@ int nvmem_device_cell_write(struct nvmem_device *nvmem, struct nvmem_cell_info *info, void *buf);
const char *nvmem_dev_name(struct nvmem_device *nvmem); +size_t nvmem_dev_size(struct nvmem_device *nvmem);
void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries);

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 --- V2: Don't introduce memleak when handling nvmem_device_read() failures
drivers/nvmem/u-boot-env.c | 78 ++++++++++++++++++-------------------- 1 file changed, 36 insertions(+), 42 deletions(-)
diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/u-boot-env.c index c4ae94af4af7..111905189341 100644 --- a/drivers/nvmem/u-boot-env.c +++ b/drivers/nvmem/u-boot-env.c @@ -23,13 +23,10 @@ enum u_boot_env_format {
struct u_boot_env { struct device *dev; + struct nvmem_device *nvmem; enum u_boot_env_format format;
struct mtd_info *mtd; - - /* Cells */ - struct nvmem_cell_info *cells; - int ncells; };
struct u_boot_env_image_single { @@ -94,70 +91,70 @@ static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, i 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; - int idx; - - priv->ncells = 0; - for (var = data; var < data + data_len && *var; var += strlen(var) + 1) - priv->ncells++; - - priv->cells = devm_kcalloc(dev, priv->ncells, sizeof(*priv->cells), GFP_KERNEL); - if (!priv->cells) - return -ENOMEM;
- for (var = data, idx = 0; + for (var = data; var < data + data_len && *var; - var = value + strlen(value) + 1, idx++) { + var = value + strlen(value) + 1) { + struct nvmem_cell_info info = {}; + eq = strchr(var, '='); if (!eq) break; *eq = '\0'; value = eq + 1;
- priv->cells[idx].name = devm_kstrdup(dev, var, GFP_KERNEL); - if (!priv->cells[idx].name) + info.name = devm_kstrdup(dev, var, GFP_KERNEL); + if (!info.name) return -ENOMEM; - priv->cells[idx].offset = data_offset + value - data; - priv->cells[idx].bytes = strlen(value); - priv->cells[idx].np = of_get_child_by_name(dev->of_node, priv->cells[idx].name); + 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")) { - priv->cells[idx].raw_len = strlen(value); - priv->cells[idx].bytes = ETH_ALEN; - priv->cells[idx].read_post_process = u_boot_env_read_post_process_ethaddr; + info.raw_len = strlen(value); + info.bytes = ETH_ALEN; + info.read_post_process = u_boot_env_read_post_process_ethaddr; } - }
- if (WARN_ON(idx != priv->ncells)) - priv->ncells = idx; + 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; - size_t bytes; uint8_t *buf; + int bytes; int err;
- buf = kcalloc(1, priv->mtd->size, GFP_KERNEL); + dev_size = nvmem_dev_size(nvmem); + + buf = kcalloc(1, dev_size, GFP_KERNEL); if (!buf) { err = -ENOMEM; goto err_out; }
- err = mtd_read(priv->mtd, 0, priv->mtd->size, &bytes, buf); - if ((err && !mtd_is_bitflip(err)) || bytes != priv->mtd->size) { - dev_err(dev, "Failed to read from mtd: %d\n", err); + bytes = nvmem_device_read(nvmem, 0, dev_size, buf); + if (bytes < 0) { + err = bytes; + goto err_kfree; + } else if (bytes != dev_size) { + err = -EIO; goto err_kfree; }
@@ -179,8 +176,8 @@ static int u_boot_env_parse(struct u_boot_env *priv) break; } crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset)); - crc32_data_len = priv->mtd->size - crc32_data_offset; - data_len = priv->mtd->size - data_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) { @@ -189,7 +186,7 @@ static int u_boot_env_parse(struct u_boot_env *priv) goto err_kfree; }
- buf[priv->mtd->size - 1] = '\0'; + 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); @@ -209,7 +206,6 @@ static int u_boot_env_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct u_boot_env *priv; - int err;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) @@ -224,17 +220,15 @@ static int u_boot_env_probe(struct platform_device *pdev) return PTR_ERR(priv->mtd); }
- err = u_boot_env_parse(priv); - if (err) - return err; - config.dev = dev; - config.cells = priv->cells; - config.ncells = priv->ncells; config.priv = priv; config.size = priv->mtd->size;
- return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config)); + priv->nvmem = devm_nvmem_register(dev, &config); + if (IS_ERR(priv->nvmem)) + return PTR_ERR(priv->nvmem); + + return u_boot_env_parse(priv); }
static const struct of_device_id u_boot_env_of_match_table[] = {

On Tue, Dec 19, 2023 at 06:40:23PM +0100, Rafał Miłecki wrote:
From: Rafał Miłecki rafal@milecki.pl
- Use nvmem_dev_size() and nvmem_device_read() to make this driver less mtd dependent
- Use nvmem_add_one_cell() to simplify adding NVMEM cells
Shouldn't this be 2 different patches?
thanks,
greg k-h

On 19.12.2023 19:13, Greg Kroah-Hartman wrote:
On Tue, Dec 19, 2023 at 06:40:23PM +0100, Rafał Miłecki wrote:
From: Rafał Miłecki rafal@milecki.pl
- Use nvmem_dev_size() and nvmem_device_read() to make this driver less mtd dependent
- Use nvmem_add_one_cell() to simplify adding NVMEM cells
Shouldn't this be 2 different patches?
I used to maintainers complaining my patches are too small and not the other way ;) I think it happened two or three times with mtd subsys.
Sure, I can split it.

Hi Rafał,
zajec5@gmail.com wrote on Tue, 19 Dec 2023 19:16:37 +0100:
On 19.12.2023 19:13, Greg Kroah-Hartman wrote:
On Tue, Dec 19, 2023 at 06:40:23PM +0100, Rafał Miłecki wrote:
From: Rafał Miłecki rafal@milecki.pl
- Use nvmem_dev_size() and nvmem_device_read() to make this driver less mtd dependent
- Use nvmem_add_one_cell() to simplify adding NVMEM cells
Shouldn't this be 2 different patches?
I used to maintainers complaining my patches are too small and not the other way ;) I think it happened two or three times with mtd subsys.
A single patch may be too small if it's alone and we don't see the big picture, otherwise I have no issue with small patches, do I? Anyway, in this case I don't mind the patch being split or kept like this, just keep my R-by applied to both if you do indeed split.
Thanks, Miquèl

From: Rafał Miłecki rafal@milecki.pl
1. Prefer kzalloc() over kcalloc() See memory-allocation.rst which says: "to be on the safe side it's best to use routines that set memory to zero, like kzalloc()" 2. Drop dev_err() for u_boot_env_add_cells() fail It can fail only on -ENOMEM. We don't want to print error then. 3. Add extra "crc32_addr" variable It makes code reading header's crc32 easier to understand / review.
Signed-off-by: Rafał Miłecki rafal@milecki.pl --- V2: New patch with suggestions from Miquel
drivers/nvmem/u-boot-env.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/u-boot-env.c index 111905189341..befbab156cda 100644 --- a/drivers/nvmem/u-boot-env.c +++ b/drivers/nvmem/u-boot-env.c @@ -132,6 +132,7 @@ static int u_boot_env_parse(struct u_boot_env *priv) size_t crc32_data_offset; size_t crc32_data_len; size_t crc32_offset; + __le32 *crc32_addr; size_t data_offset; size_t data_len; size_t dev_size; @@ -143,7 +144,7 @@ static int u_boot_env_parse(struct u_boot_env *priv)
dev_size = nvmem_dev_size(nvmem);
- buf = kcalloc(1, dev_size, GFP_KERNEL); + buf = kzalloc(dev_size, GFP_KERNEL); if (!buf) { err = -ENOMEM; goto err_out; @@ -175,7 +176,8 @@ static int u_boot_env_parse(struct u_boot_env *priv) data_offset = offsetof(struct u_boot_env_image_broadcom, data); break; } - crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset)); + crc32_addr = (__le32 *)(buf + crc32_offset); + crc32 = le32_to_cpu(*crc32_addr); crc32_data_len = dev_size - crc32_data_offset; data_len = dev_size - data_offset;
@@ -188,8 +190,6 @@ static int u_boot_env_parse(struct u_boot_env *priv)
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);

Hi Rafał,
zajec5@gmail.com wrote on Tue, 19 Dec 2023 18:40:24 +0100:
From: Rafał Miłecki rafal@milecki.pl
- Prefer kzalloc() over kcalloc() See memory-allocation.rst which says: "to be on the safe side it's best to use routines that set memory to zero, like kzalloc()"
- Drop dev_err() for u_boot_env_add_cells() fail It can fail only on -ENOMEM. We don't want to print error then.
- Add extra "crc32_addr" variable It makes code reading header's crc32 easier to understand / review.
Signed-off-by: Rafał Miłecki rafal@milecki.pl
Looks much nicer :)
Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com
Thanks, Miquèl

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 --- V2: Support new compatibles & use device_get_match_data() helper
IMPORTANT: This is based on top of the: [PATCH v6.8 1/2] nvmem: layouts: refactor .add_cells() callback arguments
MAINTAINERS | 1 + drivers/nvmem/Kconfig | 3 +- drivers/nvmem/layouts/Kconfig | 11 ++ drivers/nvmem/layouts/Makefile | 1 + drivers/nvmem/layouts/u-boot-env.c | 204 +++++++++++++++++++++++++++++ drivers/nvmem/layouts/u-boot-env.h | 15 +++ drivers/nvmem/u-boot-env.c | 158 +--------------------- 7 files changed, 235 insertions(+), 158 deletions(-) create mode 100644 drivers/nvmem/layouts/u-boot-env.c create mode 100644 drivers/nvmem/layouts/u-boot-env.h
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..dcd2ffed503c --- /dev/null +++ b/drivers/nvmem/layouts/u-boot-env.c @@ -0,0 +1,204 @@ +// 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 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; + __le32 *crc32_addr; + 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 = kzalloc(dev_size, GFP_KERNEL); + if (!buf) { + err = -ENOMEM; + goto err_out; + } + + bytes = nvmem_device_read(nvmem, 0, dev_size, buf); + if (bytes < 0) { + err = bytes; + goto err_kfree; + } else if (bytes != dev_size) { + err = -EIO; + goto err_kfree; + } + + 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_addr = (__le32 *)(buf + crc32_offset); + crc32 = le32_to_cpu(*crc32_addr); + 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); + +err_kfree: + kfree(buf); +err_out: + return err; +} +EXPORT_SYMBOL_GPL(u_boot_env_parse); + +static int u_boot_env_add_cells(struct nvmem_layout *layout) +{ + struct device *dev = &layout->dev; + enum u_boot_env_format format; + + format = (uintptr_t)device_get_match_data(dev); + + return u_boot_env_parse(dev, layout->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 const struct of_device_id u_boot_env_of_match_table[] = { + { .compatible = "u-boot,env-layout", .data = (void *)U_BOOT_FORMAT_SINGLE, }, + { .compatible = "u-boot,env-redundant-bool-layout", .data = (void *)U_BOOT_FORMAT_REDUNDANT, }, + { .compatible = "u-boot,env-redundant-count-layout", .data = (void *)U_BOOT_FORMAT_REDUNDANT, }, + { .compatible = "brcm,env-layout", .data = (void *)U_BOOT_FORMAT_BROADCOM, }, + {}, +}; + +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 befbab156cda..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) { @@ -69,134 +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; - __le32 *crc32_addr; - 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 = kzalloc(dev_size, GFP_KERNEL); - if (!buf) { - err = -ENOMEM; - goto err_out; - } - - bytes = nvmem_device_read(nvmem, 0, dev_size, buf); - if (bytes < 0) { - err = bytes; - goto err_kfree; - } else if (bytes != dev_size) { - err = -EIO; - goto err_kfree; - } - - 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_addr = (__le32 *)(buf + crc32_offset); - crc32 = le32_to_cpu(*crc32_addr); - 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); - -err_kfree: - kfree(buf); -err_out: - return err; -} - static int u_boot_env_probe(struct platform_device *pdev) { struct nvmem_config config = { @@ -228,7 +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[] = {

Hi Rafał,
zajec5@gmail.com wrote on Tue, 19 Dec 2023 18:40:25 +0100:
From: Rafał Miłecki rafal@milecki.pl
This patch moves all generic (NVMEM devices independent) code from NVMEM
Nit: In general we avoid starting with "This patch does..." and instead use the imperative form, like: "Move all generic code..."
device driver to NVMEM layout driver. Then it adds a simple NVMEM layout
Then add...
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
V2: Support new compatibles & use device_get_match_data() helper
IMPORTANT: This is based on top of the: [PATCH v6.8 1/2] nvmem: layouts: refactor .add_cells() callback arguments
Thanks for the move. Looks good to me:
Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com
Thanks, Miquèl
participants (3)
-
Greg Kroah-Hartman
-
Miquel Raynal
-
Rafał Miłecki