Re: [PATCH v2 3/4] pc-bios/s390-ccw: Move the stack array into start.S

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Tue, 27 Jun 2023 09:47:02 +0200
Thomas Huth <thuth@redhat.com> wrote:

> The stack array is only referenced from the start-up code (which is
> shared between the s390-ccw.img and the s390-netboot.img), but it is
> currently declared twice, once in main.c and once in netmain.c.
> It makes more sense to declare this in start.S instead - which will
> also be helpful in the next patch, since we need to mention the .bss
> section in start.S in that patch.
> 
> While we're at it, let's also drop the huge alignment of the stack,
> since there is no technical requirement for aligning it to page
> boundaries.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

> ---
>  pc-bios/s390-ccw/s390-ccw.h | 1 -
>  pc-bios/s390-ccw/main.c     | 1 -
>  pc-bios/s390-ccw/netmain.c  | 1 -
>  pc-bios/s390-ccw/start.S    | 6 ++++++
>  4 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h
> index b88e0550ab..91afcbbca9 100644
> --- a/pc-bios/s390-ccw/s390-ccw.h
> +++ b/pc-bios/s390-ccw/s390-ccw.h
> @@ -55,7 +55,6 @@ void consume_io_int(void);
>  /* main.c */
>  void write_subsystem_identification(void);
>  void write_iplb_location(void);
> -extern char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
>  unsigned int get_loadparm_index(void);
>  void main(void);
>  
> diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
> index a2def83e82..5506798098 100644
> --- a/pc-bios/s390-ccw/main.c
> +++ b/pc-bios/s390-ccw/main.c
> @@ -17,7 +17,6 @@
>  #include "virtio-scsi.h"
>  #include "dasd-ipl.h"
>  
> -char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
>  static SubChannelId blk_schid = { .one = 1 };
>  static char loadparm_str[LOADPARM_LEN + 1];
>  QemuIplParameters qipl;
> diff --git a/pc-bios/s390-ccw/netmain.c b/pc-bios/s390-ccw/netmain.c
> index 056e93a818..5cd619b2d6 100644
> --- a/pc-bios/s390-ccw/netmain.c
> +++ b/pc-bios/s390-ccw/netmain.c
> @@ -50,7 +50,6 @@ void write_iplb_location(void) {}
>  /* STSI 3.2.2 offset of first vmdb + offset of uuid inside vmdb */
>  #define STSI322_VMDB_UUID_OFFSET ((8 + 12) * 4)
>  
> -char stack[PAGE_SIZE * 8] __attribute__((aligned(PAGE_SIZE)));
>  IplParameterBlock iplb __attribute__((aligned(PAGE_SIZE)));
>  static char cfgbuf[2048];
>  
> diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S
> index 29b0a9ece0..111dea261b 100644
> --- a/pc-bios/s390-ccw/start.S
> +++ b/pc-bios/s390-ccw/start.S
> @@ -120,3 +120,9 @@ external_new_mask:
>      .quad   0x0000000180000000
>  io_new_mask:
>      .quad   0x0000000180000000
> +
> +.bss
> +    .align  8
> +stack:
> +    .space  STACK_SIZE
> +    .size   stack,STACK_SIZE