[U-Boot] [PATCH 08/22] x86: fsp: Mark memory used by U-Boot as reserved in the E820 table for S3

[Simon Glass]

Hi Bin,

On 16 March 2017 at 08:26, Bin Meng <bmeng.cn at gmail.com> wrote:
> U-Boot itself as well as everything that is consumed by U-Boot (like
> heap, stack, dtb, etc) needs to be reserved and reported in the E820
> table when S3 resume is on.
>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
>
>  arch/x86/Kconfig            |  8 ++++++++
>  arch/x86/lib/fsp/fsp_dram.c | 12 ++++++++++++
>  2 files changed, 20 insertions(+)

Reviewed-by: Simon Glass <sjg at chromium.org>

Can you detect if the stack space is too small?

It should be possible to measure the stack size easily enough - e.g.
using cpu_get_sp().

>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 7ea9148..95a65ff 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -583,6 +583,14 @@ config HAVE_ACPI_RESUME
>           is done, U-Boot needs to find out the wakeup vector provided by OSes
>           and jump there.
>
> +config STACK_SIZE
> +       hex
> +       depends on HAVE_ACPI_RESUME
> +       default 0x1000
> +       help
> +         Estimated U-Boot's runtime stack size that needs to be reserved
> +         during an ACPI S3 resume.
> +
>  config MAX_PIRQ_LINKS
>         int
>         default 8
> diff --git a/arch/x86/lib/fsp/fsp_dram.c b/arch/x86/lib/fsp/fsp_dram.c
> index fcfe693..417c611 100644
> --- a/arch/x86/lib/fsp/fsp_dram.c
> +++ b/arch/x86/lib/fsp/fsp_dram.c
> @@ -90,5 +90,17 @@ unsigned install_e820_map(unsigned max_entries, struct e820entry *entries)
>         entries[num_entries].type = E820_RESERVED;
>         num_entries++;
>
> +#ifdef CONFIG_HAVE_ACPI_RESUME
> +       /*
> +        * Everything between U-Boot's stack and ram top needs to be
> +        * reserved in order for ACPI S3 resume to work.
> +        */
> +       entries[num_entries].addr = gd->start_addr_sp - CONFIG_STACK_SIZE;
> +       entries[num_entries].size = gd->ram_top - gd->start_addr_sp + \
> +               CONFIG_STACK_SIZE;
> +       entries[num_entries].type = E820_RESERVED;
> +       num_entries++;
> +#endif
> +
>         return num_entries;
>  }
> --
> 2.9.2
>
Regaeds,
Simon