[U-Boot] [PATCH v1 1/2] common: fdt_support: add support for setting usable memory

Oleksandr Suvorov cryosay at gmail.com
Fri Jul 12 11:14:50 UTC 2019


On Fri, 12 Jul 2019 at 13:51, Igor Opaniuk <igor.opaniuk at gmail.com> wrote:
>
> From: Igor Opaniuk <igor.opaniuk at toradex.com>
>
> Add support for setting linux,usable-memory property in the memory
> node of device tree for the kernel [1].
>
> This property holds a base address and size, describing a
> limited region in which memory may be considered available for use by
> the kernel. Memory outside of this range is not available for use.
>
> [1] https://www.kernel.org/doc/Documentation/devicetree/bindings/chosen.txt
>
> Signed-off-by: Igor Opaniuk <igor.opaniuk at toradex.com>
> Signed-off-by: Sanchayan Maity <maitysanchayan at gmail.com>
> Signed-off-by: Stefan Agner <stefan.agner at toradex.com>
> Signed-off-by: Igor Opaniuk <igor.opaniuk at gmail.com>

Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov at toradex.com>
> ---
>
>  common/fdt_support.c  | 35 +++++++++++++++++++++++++++++++++++
>  include/fdt_support.h |  2 ++
>  2 files changed, 37 insertions(+)
>
> diff --git a/common/fdt_support.c b/common/fdt_support.c
> index f31e9b0cc5..57413c7a4d 100644
> --- a/common/fdt_support.c
> +++ b/common/fdt_support.c
> @@ -473,6 +473,41 @@ int fdt_fixup_memory(void *blob, u64 start, u64 size)
>         return fdt_fixup_memory_banks(blob, &start, &size, 1);
>  }
>
> +int fdt_set_usable_memory(void *blob, u64 start[], u64 size[], int areas)
> +{
> +       int err, nodeoffset;
> +       int len;
> +       u8 tmp[8 * 16]; /* Up to 64-bit address + 64-bit size */
> +
> +       if (areas > 8) {
> +               printf("%s: num areas %d exceeds hardcoded limit %d\n",
> +                      __func__, areas, 8);
> +               return -1;
> +       }
> +
> +       err = fdt_check_header(blob);
> +       if (err < 0) {
> +               printf("%s: %s\n", __func__, fdt_strerror(err));
> +               return err;
> +       }
> +
> +       /* find or create "/memory" node. */
> +       nodeoffset = fdt_find_or_add_subnode(blob, 0, "memory");
> +       if (nodeoffset < 0)
> +               return nodeoffset;
> +
> +       len = fdt_pack_reg(blob, tmp, start, size, areas);
> +
> +       err = fdt_setprop(blob, nodeoffset, "linux,usable-memory", tmp, len);
> +       if (err < 0) {
> +               printf("WARNING: could not set %s %s.\n",
> +                      "reg", fdt_strerror(err));
> +               return err;
> +       }
> +
> +       return 0;
> +}
> +
>  void fdt_fixup_ethernet(void *fdt)
>  {
>         int i = 0, j, prop;
> diff --git a/include/fdt_support.h b/include/fdt_support.h
> index 27fe564f0b..a868b6710e 100644
> --- a/include/fdt_support.h
> +++ b/include/fdt_support.h
> @@ -102,6 +102,8 @@ static inline int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[],
>  }
>  #endif
>
> +int fdt_set_usable_memory(void *blob, u64 start[], u64 size[], int banks);
> +
>  void fdt_fixup_ethernet(void *fdt);
>  int fdt_find_and_setprop(void *fdt, const char *node, const char *prop,
>                          const void *val, int len, int create);
> --
> 2.17.1
>
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-- 
Best regards

Oleksandr Suvorov
cryosay at gmail.com


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