[PATCH v2] LoongArch: Load vmlinux.efi to the link address

[Huacai Chen]

Reviewed-by: Huacai Chen <chenhuacai at loongson.cn>

On Sat, Nov 25, 2023 at 2:53 PM WANG Rui <wangrui at loongson.cn> wrote:
>
> Currently, kexec loads vmlinux.efi to address 0 instead of the link
> address. This causes kexec to fail to boot the new vmlinux.efi on qemu.
>
>   pei_loongarch_load: kernel_segment: 0000000000000000
>   pei_loongarch_load: kernel_entry:   00000000013f1000
>   pei_loongarch_load: image_size:     0000000001ca0000
>   pei_loongarch_load: text_offset:    0000000000200000
>   pei_loongarch_load: phys_offset:    0000000000000000
>   pei_loongarch_load: PE format:      yes
>   loongarch_load_other_segments:333: command_line: kexec console=ttyS0,115200
>   kexec_load: entry = 0x13f1000 flags = 0x1020000
>   nr_segments = 2
>   segment[0].buf   = 0x7fffeea38010
>   segment[0].bufsz = 0x1b55200
>   segment[0].mem   = (nil)
>   segment[0].memsz = 0x1ca0000
>   segment[1].buf   = 0x5555570940b0
>   segment[1].bufsz = 0x200
>   segment[1].mem   = 0x1ca0000
>   segment[1].memsz = 0x4000
>
> This patch constrains the range of the kernel segment by `hole_min`
> and `hole_max` to place vmlinux.efi exactly at the link address.
>
>   pei_loongarch_load: kernel_segment: 0000000000200000
>   pei_loongarch_load: kernel_entry:   00000000013f1000
>   pei_loongarch_load: image_size:     0000000001ca0000
>   pei_loongarch_load: text_offset:    0000000000200000
>   pei_loongarch_load: phys_offset:    0000000000000000
>   pei_loongarch_load: PE format:      yes
>   loongarch_load_other_segments:339: command_line: kexec console=ttyS0,115200
>   kexec_load: entry = 0x13f1000 flags = 0x1020000
>   nr_segments = 2
>   segment[0].buf   = 0x7ffff2028010
>   segment[0].bufsz = 0x1b55200
>   segment[0].mem   = 0x200000
>   segment[0].memsz = 0x1ca0000
>   segment[1].buf   = 0x555557498098
>   segment[1].bufsz = 0x200
>   segment[1].mem   = 0x1ea0000
>   segment[1].memsz = 0x4000
>
> Signed-off-by: WANG Rui <wangrui at loongson.cn>
> ---
>
> v1->v2:
>  * Fix the issue preventing it from working on the physical machine.
>
>  kexec/arch/loongarch/kexec-loongarch.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/kexec/arch/loongarch/kexec-loongarch.c b/kexec/arch/loongarch/kexec-loongarch.c
> index 62ff8fd..32a42d2 100644
> --- a/kexec/arch/loongarch/kexec-loongarch.c
> +++ b/kexec/arch/loongarch/kexec-loongarch.c
> @@ -265,9 +265,13 @@ unsigned long loongarch_locate_kernel_segment(struct kexec_info *info)
>                         hole = ULONG_MAX;
>                 }
>         } else {
> -               hole = locate_hole(info,
> -                       loongarch_mem.text_offset + loongarch_mem.image_size,
> -                       MiB(1), 0, ULONG_MAX, 1);
> +               unsigned long hole_min;
> +               unsigned long hole_max;
> +
> +               hole_min = loongarch_mem.text_offset;
> +               hole_max = hole_min + loongarch_mem.image_size;
> +               hole = locate_hole(info, loongarch_mem.image_size,
> +                       MiB(1), hole_min, hole_max, 1);
>
>                 if (hole == ULONG_MAX)
>                         dbgprintf("%s: locate_hole failed\n", __func__);
> --
> 2.42.0
>