On 6/28/21 8:40 AM, Ahmad Fatoum wrote:
> The Kconfig symbol already warns users that barebox updates
> that add new instances of machine_id_set_hashable may cause the machine
> ID to change making the future less useful. Recent changes allow the
> board DT to identify a specific nvmem cell to use for supplying a machine
> ID, making the old way of drivers providing machine IDs and possibly
> overriding each other no longer necessary or recommended.
I cannot parse the first sentence of the commit message.
Regards,
Bastian
>
> Make this explicit by allowing the old code to be disabled. As we only
> have a single user now and won't accept any new ones, we can remove the
> warning about it possibly changing after update.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> ---
> common/Kconfig | 18 +++++++++++-------
> common/machine_id.c | 11 ++++++++---
> drivers/nvmem/Kconfig | 1 +
> drivers/nvmem/ocotp.c | 7 ++++++-
> include/machine_id.h | 16 ----------------
> 5 files changed, 26 insertions(+), 27 deletions(-)
> delete mode 100644 include/machine_id.h
>
> diff --git a/common/Kconfig b/common/Kconfig
> index a4a109f04f08..a2aa0b2568de 100644
> --- a/common/Kconfig
> +++ b/common/Kconfig
> @@ -1069,13 +1069,11 @@ config MACHINE_ID
> select NVMEM
> help
> Compute a persistent machine-specific id and store it to $global.machine_id.
> - The id is a hash of device-specific information added either via
> - machine_id_set_hashable() or by hashing the nvmem cell referenced by the
> - /chosen/barebox,machine-id device tree property.
> -
> - With machine_id_set_hashable(), the last call prior to the late initcall
> - set_machine_id() willl be used to generate the machine id. This means
> - updating barebox may change the machine id!
> + The id is a hash of device-specific information. This information
> + comes from the nvmem cell device tree node path described by the
> + /chosen/barebox,machine-id-path property. As a special case, the i.MX6 OCOTP
> + driver supplies the SoC UID as hashable for when /chosen/barebox,machine-id-path
> + is not specified.
>
> global.bootm.provide_machine_id may be used to automatically set
> the linux.bootargs.machine_id global variable with a value of
> @@ -1084,6 +1082,12 @@ config MACHINE_ID
> Note: if no hashable information is available no machine id will be passed
> to the kernel.
>
> +config MACHINE_ID_LEGACY
> + bool
> + help
> + Selected by i.MX OCOTP driver, so it can set the SoC UID as hashable.
> + New platforms should use /chosen/barebox,machine-id-path instead.
> +
> config SYSTEMD_OF_WATCHDOG
> bool "inform devicetree-enabled kernel of used watchdog"
> depends on WATCHDOG && OFTREE && FLEXIBLE_BOOTARGS
> diff --git a/common/machine_id.c b/common/machine_id.c
> index fd2f0888a6cd..8303c0b7aa87 100644
> --- a/common/machine_id.c
> +++ b/common/machine_id.c
> @@ -9,23 +9,24 @@
> #include <globalvar.h>
> #include <magicvar.h>
> #include <crypto/sha.h>
> -#include <machine_id.h>
> #include <linux/err.h>
> #include <linux/nvmem-consumer.h>
> #include <of.h>
>
> #define MACHINE_ID_LENGTH 32
>
> +#ifdef CONFIG_MACHINE_ID_LEGACY
> static void *__machine_id_hashable;
> static size_t __machine_id_hashable_length;
>
> -
> +/* Shouldn't be called from new code */
> +void machine_id_set_hashable(const void *hashable, size_t len);
> void machine_id_set_hashable(const void *hashable, size_t len)
> {
> -
> __machine_id_hashable = xmemdup(hashable, len);
> __machine_id_hashable_length = len;
> }
> +#endif
>
> static const void *machine_id_get_hashable(size_t *len)
> {
> @@ -52,8 +53,12 @@ static const void *machine_id_get_hashable(size_t *len)
> return ret;
>
> no_cell:
> +#ifdef CONFIG_MACHINE_ID_LEGACY
> *len = __machine_id_hashable_length;
> return __machine_id_hashable;
> +#else
> + return NULL;
> +#endif
> }
>
> static int machine_id_set_globalvar(void)
> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
> index 3781f7a839fc..08a5765573a8 100644
> --- a/drivers/nvmem/Kconfig
> +++ b/drivers/nvmem/Kconfig
> @@ -25,6 +25,7 @@ config NVMEM_SNVS_LPGPR
> config IMX_OCOTP
> tristate "i.MX6 On Chip OTP controller"
> depends on ARCH_IMX6 || ARCH_VF610 || ARCH_IMX8M || ARCH_IMX7
> + select MACHINE_ID_LEGACY
> depends on OFDEVICE
> help
> This adds support for the i.MX6 On-Chip OTP controller. Currently the
> diff --git a/drivers/nvmem/ocotp.c b/drivers/nvmem/ocotp.c
> index b2fad3c68770..0b10e52a86ba 100644
> --- a/drivers/nvmem/ocotp.c
> +++ b/drivers/nvmem/ocotp.c
> @@ -29,7 +29,6 @@
> #include <regmap.h>
> #include <linux/clk.h>
> #include <mach/ocotp.h>
> -#include <machine_id.h>
> #include <mach/ocotp-fusemap.h>
> #include <linux/nvmem-provider.h>
>
> @@ -689,6 +688,7 @@ static int imx_ocotp_read(void *ctx, unsigned offset, void *val, size_t bytes)
>
> static void imx_ocotp_set_unique_machine_id(void)
> {
> + extern void machine_id_set_hashable(const void *hashable, size_t len);
> uint32_t unique_id_parts[UNIQUE_ID_NUM];
> int i;
>
> @@ -785,6 +785,11 @@ static int imx_ocotp_probe(struct device_d *dev)
> ethaddr->value, ethaddr);
> }
>
> + /* Special case: new machine id providers should provide a nvmem cell
> + * and reference its path via /chosen/barebox,machine-id-path.
> + * For i.MX, we support the legacy way of the driver supplying the
> + * hash instead
> + */
> if (IS_ENABLED(CONFIG_MACHINE_ID))
> imx_ocotp_set_unique_machine_id();
>
> diff --git a/include/machine_id.h b/include/machine_id.h
> deleted file mode 100644
> index 31d5e0bb2851..000000000000
> --- a/include/machine_id.h
> +++ /dev/null
> @@ -1,16 +0,0 @@
> -#ifndef __MACHINE_ID_H__
> -#define __MACHINE_ID_H__
> -
> -#if IS_ENABLED(CONFIG_MACHINE_ID)
> -
> -void machine_id_set_hashable(const void *hashable, size_t len);
> -
> -#else
> -
> -static inline void machine_id_set_hashable(const void *hashable, size_t len)
> -{
> -}
> -
> -#endif /* CONFIG_MACHINE_ID */
> -
> -#endif /* __MACHINE_ID_H__ */
>
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