Independ of my opinion on the whole scheme that I shared last time,
we really should not bloat struct device with function pointers.
On Fri, Sep 25, 2020 at 11:19:18AM -0500, Tony Asleson wrote:
> Function callback and function to be used to write a persistent
> durable name to the supplied character buffer. This will be used to add
> structured key-value data to log messages for hardware related errors
> which allows end users to correlate message and specific hardware.
>
> Signed-off-by: Tony Asleson <tasleson@xxxxxxxxxx>
> ---
> drivers/base/core.c | 24 ++++++++++++++++++++++++
> include/linux/device.h | 4 ++++
> 2 files changed, 28 insertions(+)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 05d414e9e8a4..88696ade8bfc 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -2489,6 +2489,30 @@ int dev_set_name(struct device *dev, const char *fmt, ...)
> }
> EXPORT_SYMBOL_GPL(dev_set_name);
>
> +/**
> + * dev_durable_name - Write "DURABLE_NAME"=<durable name> in buffer
> + * @dev: device
> + * @buffer: character buffer to write results
> + * @len: length of buffer
> + * @return: Number of bytes written to buffer
> + */
> +int dev_durable_name(const struct device *dev, char *buffer, size_t len)
> +{
> + int tmp, dlen;
> +
> + if (dev && dev->durable_name) {
> + tmp = snprintf(buffer, len, "DURABLE_NAME=");
> + if (tmp < len) {
> + dlen = dev->durable_name(dev, buffer + tmp,
> + len - tmp);
> + if (dlen > 0 && ((dlen + tmp) < len))
> + return dlen + tmp;
> + }
> + }
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(dev_durable_name);
> +
> /**
> * device_to_dev_kobj - select a /sys/dev/ directory for the device
> * @dev: device
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 5efed864b387..074125999dd8 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -614,6 +614,8 @@ struct device {
> struct iommu_group *iommu_group;
> struct dev_iommu *iommu;
>
> + int (*durable_name)(const struct device *dev, char *buff, size_t len);
> +
> bool offline_disabled:1;
> bool offline:1;
> bool of_node_reused:1;
> @@ -655,6 +657,8 @@ static inline const char *dev_name(const struct device *dev)
> extern __printf(2, 3)
> int dev_set_name(struct device *dev, const char *name, ...);
>
> +int dev_durable_name(const struct device *d, char *buffer, size_t len);
> +
> #ifdef CONFIG_NUMA
> static inline int dev_to_node(struct device *dev)
> {
> --
> 2.26.2
>
---end quoted text---
