Hi Ard,
On Sun, Sep 18, 2022 at 11:35:41PM +0200, Ard Biesheuvel wrote:
> Expose the EFI boot time memory map to the kernel via a configuration
> table. This is arch agnostic and enables future changes that remove the
> dependency on DT on architectures that don't otherwise rely on it.
>
> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> ---
> drivers/firmware/efi/libstub/arm64-stub.c | 2 +-
> drivers/firmware/efi/libstub/efi-stub-helper.c | 2 +-
> drivers/firmware/efi/libstub/efistub.h | 3 ++-
> drivers/firmware/efi/libstub/mem.c | 26 ++++++++++++++++++--
> drivers/firmware/efi/libstub/randomalloc.c | 2 +-
> drivers/firmware/efi/libstub/relocate.c | 2 +-
> include/linux/efi.h | 1 +
> 7 files changed, 31 insertions(+), 7 deletions(-)
>
[..]
> diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c
> index 40721573e494..ed4c145afe11 100644
> --- a/drivers/firmware/efi/libstub/mem.c
> +++ b/drivers/firmware/efi/libstub/mem.c
> @@ -9,14 +9,20 @@
> * efi_get_memory_map() - get memory map
> * @map: pointer to memory map pointer to which to assign the
> * newly allocated memory map
> + * @install_cfg_tbl: whether or not to install the boot memory map as a
> + * configuration table
> *
> * 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_status_t efi_get_memory_map(struct efi_boot_memmap **map,
> + bool install_cfg_tbl)
> {
> + int memtype = install_cfg_tbl ? EFI_ACPI_RECLAIM_MEMORY
> + : EFI_LOADER_DATA;
> + efi_guid_t tbl_guid = LINUX_EFI_BOOT_MEMMAP_GUID;
> struct efi_boot_memmap *m, tmp;
> efi_status_t status;
> unsigned long size;
> @@ -28,11 +34,23 @@ efi_status_t efi_get_memory_map(struct efi_boot_memmap **map)
> return EFI_LOAD_ERROR;
>
> size = tmp.map_size + tmp.desc_size * EFI_MMAP_NR_SLACK_SLOTS;
> - status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*m) + size,
> + status = efi_bs_call(allocate_pool, memtype, sizeof(*m) + size,
> (void **)&m);
> if (status != EFI_SUCCESS)
> return status;
>
> + if (install_cfg_tbl) {
> + /*
> + * Installing a configuration table might allocate memory, and
> + * this may modify the memory map. This means we should install
> + * the configuration table first, and re-install or delete it
> + * as needed.
> + */
> + status = efi_bs_call(install_configuration_table, &tbl_guid, m);
> + if (status != EFI_SUCCESS)
> + goto free_map;
> + }
> +
> m->buff_size = m->map_size = size;
> status = efi_bs_call(get_memory_map, &m->map_size, m->map, &m->map_key,
> &m->desc_size, &m->desc_ver);
> @@ -40,6 +58,10 @@ efi_status_t efi_get_memory_map(struct efi_boot_memmap **map)
> if (status == EFI_SUCCESS) {
> *map = m;
> } else {
> + if (install_cfg_tbl)
> + efi_bs_call(install_configuration_table, &tbl_guid,
> + NULL);
> +free_map:
> efi_bs_call(free_pool, m);
> }
You have another commit about removing goto kludges, so maybe write this like the following,
rather than a goto into an 'else' statement?
diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c
index feef8d4be113..2f22ef7c5232 100644
--- a/drivers/firmware/efi/libstub/mem.c
+++ b/drivers/firmware/efi/libstub/mem.c
@@ -64,10 +64,12 @@ efi_status_t efi_get_memory_map(struct efi_boot_memmap *map)
*map->key_ptr = key;
if (map->desc_ver)
*map->desc_ver = desc_version;
- } else {
- efi_bs_call(free_pool, m);
}
+free_map:
+ if (status != EFI_SUCCESS)
+ efi_bs_call(free_pool, m);
+
fail:
*map->map = m;
return status;
(This is a diff against next-20220920, not your branch, but you get the idea)
Thanks,
Joey
