Re: [PATCH 2/2] lmb: consider EFI memory map

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

Hi Heinrich, 

This looks reasonable to me as a short term solution, but I'd feel safer if
someone else had a look at it

On Wed, Jan 04, 2023 at 05:26:06AM +0100, Heinrich Schuchardt wrote:
> Add reservations for all EFI memory areas that are not
> EFI_CONVENTIONAL_MEMORY.
> 
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> ---
>  lib/lmb.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/lib/lmb.c b/lib/lmb.c
> index c599608fa3..aee2617593 100644
> --- a/lib/lmb.c
> +++ b/lib/lmb.c
> @@ -7,7 +7,9 @@
>   */
>  
>  #include <common.h>
> +#include <efi_loader.h>
>  #include <image.h>
> +#include <mapmem.h>
>  #include <lmb.h>
>  #include <log.h>
>  #include <malloc.h>
> @@ -153,6 +155,46 @@ void arch_lmb_reserve_generic(struct lmb *lmb, ulong sp, ulong end, ulong align)
>  	}
>  }
>  
> +/**
> + * efi_lmb_reserve() - add reservations for EFI memory
> + *
> + * Add reservations for all EFI memory areas that are not
> + * EFI_CONVENTIONAL_MEMORY.
> + *
> + * @lmb:	lmb environment
> + * Return:	0 on success, 1 on failure
> + */
> +static __maybe_unused int efi_lmb_reserve(struct lmb *lmb)
> +{
> +	struct efi_mem_desc *memmap = NULL, *map;
> +	efi_uintn_t i, map_size = 0;
> +	efi_status_t ret;
> +
> +	ret = efi_get_memory_map(&map_size, memmap, NULL, NULL, NULL);
> +	if (ret == EFI_BUFFER_TOO_SMALL) {
> +		map_size += sizeof(struct efi_mem_desc); /* for my own */
> +		ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, map_size,
> +					(void *)&memmap);
> +		if (ret != EFI_SUCCESS)
> +			return 1;
> +		ret = efi_get_memory_map(&map_size, memmap, NULL, NULL, NULL);
> +	}
> +	if (ret != EFI_SUCCESS) {
> +		efi_free_pool(memmap);
> +		return 1;
> +	}

We got a very similar piece of code in cmd/efidebug.c.  I think we are
better off adding a function that just calls efi_get_memory_map() and
returns the map + map_size, instead of duplicating that 

> +
> +	for (i = 0, map = memmap; i < map_size / sizeof(*map); ++map, ++i) {
> +		if (map->type != EFI_CONVENTIONAL_MEMORY)
> +			lmb_reserve(lmb,
> +				    map_to_sysmem((void *)(uintptr_t)
> +						  map->physical_start),
> +				    map->num_pages * EFI_PAGE_SIZE);
> +	}
> +	efi_free_pool(memmap);
> +	return 0;
> +}
> +
>  static void lmb_reserve_common(struct lmb *lmb, void *fdt_blob)
>  {
>  	arch_lmb_reserve(lmb);
> @@ -160,6 +202,9 @@ static void lmb_reserve_common(struct lmb *lmb, void *fdt_blob)
>  
>  	if (CONFIG_IS_ENABLED(OF_LIBFDT) && fdt_blob)
>  		boot_fdt_add_mem_rsv_regions(lmb, fdt_blob);
> +
> +	if (CONFIG_IS_ENABLED(EFI_LOADER))
> +		efi_lmb_reserve(lmb);
>  }
>  
>  /* Initialize the struct, add memory and call arch/board reserve functions */
> -- 
> 2.37.2
> 

Other than that this looks fine

Cheers
/Ilias