Hi Michael,
On Wed, 19 Feb 2020 at 11:43, Michael Trimarchi
wrote:
>
> We need to reserve memory and not put in kernel linear mapping.
> This avoid problem during memory remapping from the simple
> frame buffer in linux kernel
>
> Signed-off-by: Michael Trimarchi
> ---
> common/fdt_support.c | 40
> include/fdt_support.h | 11 +++
> 2 files changed, 51 insertions(+)
Reviewed-by: Simon Glass
nits below
>
> diff --git a/common/fdt_support.c b/common/fdt_support.c
> index 02cf5c6241..a3662f4358 100644
> --- a/common/fdt_support.c
> +++ b/common/fdt_support.c
> @@ -410,6 +410,46 @@ static int fdt_pack_reg(const void *fdt, void *buf, u64
> *address, u64 *size,
> return p - (char *)buf;
> }
>
> +int fdt_fixup_reserved_memory(void *blob, const char *area, u64 start[], u64
> size[])
> +{
> + int offs, len;
> + const char *subpath;
> + const char *path = "/reserved-memory";
> + fdt32_t address_cells = cpu_to_fdt32(fdt_address_cells(blob, 0));
> + fdt32_t size_cells = cpu_to_fdt32(fdt_size_cells(blob, 0));
> + u8 temp[16]; /* Up to 64-bit address + 64-bit size */
> +
> + offs = fdt_path_offset(blob, path);
> + if (offs < 0) {
> + debug("Node %s not found\n", path);
> + path = "/";
> + subpath = "reserved-memory";
> + offs = fdt_path_offset(blob, path);
This is always 0 by definition.
> + offs = fdt_add_subnode(blob, offs, subpath);
> + if (offs < 0) {
> + printf("Could not create %s%s node.\n", path,
> subpath);
> + return -1;
This is -EPERM. I think it would be better to return ofs.
> + }
> + path = "/reserved-memory";
> + offs = fdt_path_offset(blob, path);
> +
> + fdt_setprop(blob, offs, "#address-cells", _cells,
> sizeof(address_cells));
> + fdt_setprop(blob, offs, "#size-cells", _cells,
> sizeof(size_cells));
> + fdt_setprop(blob, offs, "ranges", NULL, 0);
> + }
> +
> + offs = fdt_add_subnode(blob, offs, area ? : "private");
> + if (offs < 0) {
> + printf("Could not create %s%s node.\n", path, subpath);
> + return -1;
and here
> + }
> +
> + fdt_setprop(blob, offs, "no-map", NULL, 0);
> + len = fdt_pack_reg(blob, temp, start, size, 1);
> + fdt_setprop(blob, offs, "reg", temp, len);
blank line before return
> + return 0;
> +}
> +
> #if CONFIG_NR_DRAM_BANKS > 4
> #define MEMORY_BANKS_MAX CONFIG_NR_DRAM_BANKS
> #else
> diff --git a/include/fdt_support.h b/include/fdt_support.h
> index ba14acd7f6..7c8a280f53 100644
> --- a/include/fdt_support.h
> +++ b/include/fdt_support.h
> @@ -93,6 +93,17 @@ void do_fixup_by_compat_u32(void *fdt, const char *compat,
> */
> int fdt_fixup_memory(void *blob, u64 start, u64 size);
>
> +/**
> + * Setup the memory reserved node in the DT. Creates one if none was
> existing before.
> + *
> + * @param blob FDT blob to update
> + * @param area Reserved area name
> + * @param startBegin of DRAM mapping in physical memory
> + * @param size Size of the single memory bank
> + * @return 0 if ok, or -1 or -FDT_ERR_... on error
check this
> + */
> +int fdt_fixup_reserved_memory(void *blob, const char *area, u64 start[], u64
> size[]);
> +
> /**
> * Fill the DT memory node with multiple memory banks.
> * Creates the node if none was existing before.
> --
> 2.17.1
>
Regards,
Simon
