[Skiboot] [PATCH 1/3] core/platform: Add finalise_dt() callback

[Vaidyanathan Srinivasan]

* Oliver O'Halloran <oohall at gmail.com> [2019-07-11 17:41:42]:

> Previously the platform.exit() callback was called before we created the
> flattened device tree blob for Linux. Some platforms used this to add
> various DT properties and this was broken in commit Fixes: 9fc0c1287ada
> ("Move FSP specific op-panel calls to platform.exit()") which moved the
> exit callback to after the DTB had been created.
> 
> The logic for moving the time of the exit call makes some sense since we
> want to terminate the IPMI watchdog timer as late as possible, but we
> still need a way for the platform modify the DTB as late as possible.
> 
> This patch adds another platform callback (yay!) called finalise_dt()
> which can be used to graft stuff into the DT.
> 
> Suggested-by: Vaidyanathan Srinivasan <svaidy at linux.ibm.com>
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
> ---
>  core/init.c        | 3 +++
>  include/platform.h | 6 ++++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/core/init.c b/core/init.c
> index d0f28f26d400..271736be8325 100644
> --- a/core/init.c
> +++ b/core/init.c
> @@ -579,6 +579,9 @@ void __noreturn load_and_boot_kernel(bool is_reboot)
>  
>  	add_fast_reboot_dt_entries();
>  
> +	if (platform.finalise_dt)
> +		platform.finalise_dt(is_reboot);
> +
>  	/* Create the device tree blob to boot OS. */
>  	fdt = create_dtb(dt_root, false);
>  	if (!fdt) {
> diff --git a/include/platform.h b/include/platform.h
> index 0326e1a247e4..da27c03ac363 100644
> --- a/include/platform.h
> +++ b/include/platform.h
> @@ -252,8 +252,14 @@ struct platform {
>  	 */
>  	int		(*resource_loaded)(enum resource_id id, uint32_t idx);
>  
> +	/*
> +	 * Executed just prior to creating the dtb for the kernel.
> +	 */
> +	void		(*finalise_dt)(bool is_reboot);
> +
>  	/*
>  	 * Executed just prior to handing control over to the payload.
> +	 * Used to terminate watchdogs, etc.
>  	 */
>  	void		(*exit)(void);
>  

Thanks Oliver, This is a good idea and cleaner to add more stuff into
the DT callbacks.

Reviewed-by: Vaidyanathan Srinivasan <svaidy at linux.ibm.com>

--Vaidy