Re: [PATCH 2/7] pc-bios: s390x: Cleanup jump to ipl code

[Thomas Huth]

On 15/07/2020 11.40, Janosch Frank wrote:
> jump_to_IPL_code takes a 64 bit address, masks it with the short psw
> address mask and later branches to it using a full 64 bit register.
> 
> * As the masking is not necessary, let's remove it
> * Without the mask we can save the ipl address to a static 64 bit
>   function ptr as we later branch to it
> * Let's also clean up the variable names and remove the now unneeded
>   ResetInfo
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  pc-bios/s390-ccw/jump2ipl.c | 27 +++++++++++----------------
>  1 file changed, 11 insertions(+), 16 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c
> index 767012bf0c..aef37cea76 100644
> --- a/pc-bios/s390-ccw/jump2ipl.c
> +++ b/pc-bios/s390-ccw/jump2ipl.c
> @@ -13,20 +13,15 @@
>  #define KERN_IMAGE_START 0x010000UL
>  #define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
>  
> -typedef struct ResetInfo {
> -    uint64_t ipl_psw;
> -    uint32_t ipl_continue;
> -} ResetInfo;
> -
> -static ResetInfo save;
> +static void (*ipl_continue)(void);
> +static uint64_t psw_save;

Christian, do you remember whether there was a reason that we saved the
"ipl_continue" in the low-core in the past?

The changes here look ok to me, but I still wonder why it has been more
"complicated" before...?

Acked-by: Thomas Huth <thuth@redhat.com>