[OpenBIOS] [PATCH] Implement new pv_align_mem_alloc romvec interface for allocating aligned memory.

[Blue Swirl]

On Tue, Apr 19, 2011 at 1:31 AM, Mark Cave-Ayland
<mark.cave-ayland at siriusit.co.uk> wrote:
> When attempting to load kadb from a Solaris 8 CD at boot, it seems that in order
> for kadb to allocate enough memory to load the kernel (and its modules) the
> /openprom/aligned-allocator property must be present with length zero.

Awesome work!

> This has the additional side-effect that OpenBIOS memory allocations are
> redirected to a new romvec offset when this property is detected, which appears
> to have a similar interface to obp_dumb_memalloc() but with an extra
> alignment parameter. Hence we include a simple implementation which seems
> to be enough to be able to get kadb to load and attach to the kernel.
>
> ---
>  openbios-devel/arch/sparc32/call-romvec.S |    1 +
>  openbios-devel/arch/sparc32/lib.c         |   28 +++++++++++++++++-----------
>  openbios-devel/arch/sparc32/openprom.h    |    5 ++++-
>  openbios-devel/arch/sparc32/romvec.c      |    2 ++
>  openbios-devel/arch/sparc32/romvec.h      |    2 ++
>  openbios-devel/arch/sparc32/tree.fs       |    3 +++
>  6 files changed, 29 insertions(+), 12 deletions(-)
>
> diff --git a/openbios-devel/arch/sparc32/call-romvec.S b/openbios-devel/arch/sparc32/call-romvec.S
> index 1e8f754..2b2dfe0 100644
> --- a/openbios-devel/arch/sparc32/call-romvec.S
> +++ b/openbios-devel/arch/sparc32/call-romvec.S
> @@ -89,4 +89,5 @@ ROMVEC_HANDLER(obp_proplen)
>  ROMVEC_HANDLER(obp_getprop)
>  ROMVEC_HANDLER(obp_setprop)
>  ROMVEC_HANDLER(obp_nextprop)
> +ROMVEC_HANDLER(obp_align_memalloc)
>
> diff --git a/openbios-devel/arch/sparc32/lib.c b/openbios-devel/arch/sparc32/lib.c
> index 01fa570..b975fd4 100644
> --- a/openbios-devel/arch/sparc32/lib.c
> +++ b/openbios-devel/arch/sparc32/lib.c
> @@ -347,10 +347,25 @@ void ofmem_arch_early_map_pages(phys_addr_t phys, ucell virt, ucell size, ucell
>     map_pages(phys, virt, size, mode);
>  }
>
> -char *obp_dumb_memalloc(char *va, unsigned int size)
> +char *obp_align_memalloc(char *va, unsigned int size, unsigned int align)
>  {
>     phys_addr_t phys;
>     ucell virt;
> +
> +    /* Claim physical memory */
> +    phys = ofmem_claim_phys(-1, size, align);
> +
> +    /* Claim virtual memory */
> +    virt = ofmem_claim_virt(pointer2cell(va), size, 0);
> +
> +    /* Map the memory */
> +    ofmem_map(phys, virt, size, ofmem_arch_default_translation_mode(phys));
> +
> +    return cell2pointer(virt);
> +}
> +
> +char *obp_dumb_memalloc(char *va, unsigned int size)
> +{
>     unsigned long align;
>     int i;
>
> @@ -371,16 +386,7 @@ char *obp_dumb_memalloc(char *va, unsigned int size)
>         align++;
>     }
>
> -    /* Claim physical memory */
> -    phys = ofmem_claim_phys(-1, size, align);
> -
> -    /* Claim virtual memory */
> -    virt = ofmem_claim_virt(pointer2cell(va), size, 0);
> -
> -    /* Map the memory */
> -    ofmem_map(phys, virt, size, ofmem_arch_default_translation_mode(phys));
> -
> -    return cell2pointer(virt);
> +    return obp_align_memalloc(va, size, align);
>  }
>
>  void obp_dumb_memfree(__attribute__((unused))char *va,
> diff --git a/openbios-devel/arch/sparc32/openprom.h b/openbios-devel/arch/sparc32/openprom.h
> index 0a2074b..5f05014 100644
> --- a/openbios-devel/arch/sparc32/openprom.h
> +++ b/openbios-devel/arch/sparc32/openprom.h
> @@ -135,7 +135,10 @@ struct linux_romvec {
>        struct linux_bootargs_v2 pv_v2bootargs;
>        struct linux_dev_v2_funcs pv_v2devops;
>
> -       int filler[15];
> +       /* Allocate memory to specified alignment */
> +       char * (*pv_align_mem_alloc)(char *va, unsigned int size, unsigned int align);
> +
> +       int filler[11];

This would shorten the structure by 12 bytes, please use 14 instead of 11.