On Mon, 17 Feb 2020 at 22:14, Heinrich Schuchardt <xypron.glpk@xxxxxx> wrote:
>
> Provide descriptions of:
>
> * efi_get_memory_map()
> * efi_low_alloc_above()
> * efi_free()
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@xxxxxx>
Thanks Heinrich. One comment below.
> ---
> drivers/firmware/efi/libstub/mem.c | 31 ++++++++++++++++++++++++++++--
> 1 file changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c
> index c25fd9174b74..be24c062115f 100644
> --- a/drivers/firmware/efi/libstub/mem.c
> +++ b/drivers/firmware/efi/libstub/mem.c
> @@ -16,6 +16,15 @@ static inline bool mmap_has_headroom(unsigned long buff_size,
> return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS;
> }
>
> +/**
> + * efi_get_memory_map() - get memory map
> + * @map on return pointer to memory map
> + *
> + * Retrieve the UEFI memory map. The allocated memory leaves room for
> + * up to EFI_MMAP_NR_SLACK_SLOTS additional memory map entries.
> + *
> + * Return: status code
> + */
> efi_status_t efi_get_memory_map(struct efi_boot_memmap *map)
> {
> efi_memory_desc_t *m = NULL;
> @@ -109,8 +118,20 @@ efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr,
> }
> return EFI_SUCCESS;
> }
> -/*
> - * Allocate at the lowest possible address that is not below 'min'.
> +/**
> + * efi_low_alloc_above() - allocate pages at or above given address
> + * @size: size of the memory area to allocate
> + * @align: minimum alignment of the allocated memory area. It should
> + * a power of two.
> + * @addr: on exit the address of the allocated memory
> + * @min: minimum address to used for the memory allocation
> + *
> + * Allocate at the lowest possible address that is not below 'min' as
> + * EFI_LOADER_DATA. The allocated pages are aligned according to 'align' but at
> + * least EFI_ALLOC_ALIGN. The first allocated page will not below the address
> + * given by 'min'.
> + *
> + * Return: status code
> */
> efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
> unsigned long *addr, unsigned long min)
> @@ -187,6 +208,12 @@ efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
> return status;
> }
>
> +/**
> + * efi_free() - free memory pages
> + * @size size of the memory area to free in bytes
> + * @addr start of the memory area to free (must be EFI_PAGE_SIZE
> + * aligned)
> + */
It may be good to mention here that the allocation is rounded up to
EFI_ALLOC_ALIGN again, so it should only be used for allocation that
were made using efi_allocate_pages() or efi_low_alloc_above().
> void efi_free(unsigned long size, unsigned long addr)
> {
> unsigned long nr_pages;
> --
> 2.25.0
>
