[PATCH 17/40] lmb: introduce a function to add memory to the lmb memory map

[Simon Glass]

Hi Sughosh,

On Wed, 24 Jul 2024 at 00:04, Sughosh Ganu <sughosh.ganu at linaro.org> wrote:
>
> Introduce a function lmb_add_memory() to add available memory to the
> LMB memory map. Call this function during board init once the LMB data
> structures have been initialised.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> ---
> Changes since rfc: None
>
>  include/lmb.h | 12 ++++++++++++
>  lib/lmb.c     | 42 ++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 54 insertions(+)
>
> diff --git a/include/lmb.h b/include/lmb.h
> index a308796d58..77e2a23c0d 100644
> --- a/include/lmb.h
> +++ b/include/lmb.h
> @@ -40,6 +40,18 @@ struct lmb_region {
>  void lmb_init_and_reserve(struct bd_info *bd, void *fdt_blob);
>  void lmb_init_and_reserve_range(phys_addr_t base, phys_size_t size,
>                                 void *fdt_blob);
> +
> +/**
> + * lmb_add_memory() - Add memory range for LMB allocations
> + *
> + * Add the entire available memory range to the pool of memory that
> + * can be used by the LMB module for allocations.
> + *
> + * Return: None
> + *
> + */
> +void lmb_add_memory(void);
> +
>  long lmb_add(phys_addr_t base, phys_size_t size);
>  long lmb_reserve(phys_addr_t base, phys_size_t size);
>  /**
> diff --git a/lib/lmb.c b/lib/lmb.c
> index 88352e9a25..db0874371a 100644
> --- a/lib/lmb.c
> +++ b/lib/lmb.c
> @@ -239,6 +239,46 @@ void lmb_init_and_reserve(struct bd_info *bd, void *fdt_blob)
>         lmb_reserve_common(fdt_blob);
>  }
>
> +/**
> + * lmb_add_memory() - Add memory range for LMB allocations
> + *
> + * Add the entire available memory range to the pool of memory that
> + * can be used by the LMB module for allocations.
> + *
> + * This can be overridden for specific boards/architectures.

Why is this needed? I'm really not a fan of weak functions...it often
means we should have a proper API for it.

> + *
> + * Return: None
> + *
> + */
> +__weak void lmb_add_memory(void)
> +{
> +       int i;
> +       phys_size_t size;
> +       phys_addr_t rgn_top;
> +       u64 ram_top = gd->ram_top;
> +       struct bd_info *bd = gd->bd;
> +
> +       /* Assume a 4GB ram_top if not defined */
> +       if (!ram_top)
> +               ram_top = 0x100000000ULL;
> +
> +       for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
> +               size = bd->bi_dram[i].size;
> +               if (size) {
> +                       if (bd->bi_dram[i].start > ram_top)
> +                               continue;
> +
> +                       rgn_top = bd->bi_dram[i].start +
> +                               bd->bi_dram[i].size;
> +
> +                       if (rgn_top > ram_top)
> +                               size -= rgn_top - ram_top;
> +
> +                       lmb_add(bd->bi_dram[i].start, size);
> +               }
> +       }
> +}
> +
>  /* Initialize the struct, add memory and call arch/board reserve functions */
>  void lmb_init_and_reserve_range(phys_addr_t base, phys_size_t size,
>                                 void *fdt_blob)
> @@ -728,5 +768,7 @@ int lmb_mem_regions_init(void)
>                 return -1;
>         }
>
> +       lmb_add_memory();
> +
>         return 0;
>  }
> --
> 2.34.1
>

Regards,
Simon