On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
> From: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
>
> There are two problems with the UEFI stub DT memory node removal
> routine:
> - it deletes nodes as it traverses the tree, which happens to work
> but is not supported, as deletion invalidates the node iterator;
> - deleting memory nodes entirely may discard annotations in the form
> of additional properties on the nodes.
>
> Since the discovery of DT memory nodes occurs strictly before the
> UEFI init sequence, we can simply clear the memblock memory table
> before parsing the UEFI memory map. This way, it is no longer
> necessary to remove the nodes, so we can remove that logic from the
> stub as well.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
> ---
> drivers/firmware/efi/arm-init.c | 8 ++++++++
> drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
> 2 files changed, 9 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
> index aa1f743..5d6945b 100644
> --- a/drivers/firmware/efi/arm-init.c
> +++ b/drivers/firmware/efi/arm-init.c
> @@ -143,6 +143,14 @@ static __init void reserve_regions(void)
> if (efi_enabled(EFI_DBG))
> pr_info("Processing EFI memory map:\n");
>
> + /*
> + * Discard memblocks discovered so far: if there are any at this
> + * point, they originate from memory nodes in the DT, and UEFI
> + * uses its own memory map instead.
> + */
> + memblock_dump_all();
> + memblock_remove(0, ULLONG_MAX);
> +
Does this change need to be applied to any other architectures given
that deletion code has been removed from libstub below?
Cheers,
--
Steve
> for_each_efi_memory_desc(&memmap, md) {
> paddr = md->phys_addr;
> npages = md->num_pages;
> diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
> index 6dba78a..e58abfa 100644
> --- a/drivers/firmware/efi/libstub/fdt.c
> +++ b/drivers/firmware/efi/libstub/fdt.c
> @@ -24,7 +24,7 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
> unsigned long map_size, unsigned long desc_size,
> u32 desc_ver)
> {
> - int node, prev, num_rsv;
> + int node, num_rsv;
> int status;
> u32 fdt_val32;
> u64 fdt_val64;
> @@ -54,28 +54,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
> goto fdt_set_fail;
>
> /*
> - * Delete any memory nodes present. We must delete nodes which
> - * early_init_dt_scan_memory may try to use.
> - */
> - prev = 0;
> - for (;;) {
> - const char *type;
> - int len;
> -
> - node = fdt_next_node(fdt, prev, NULL);
> - if (node < 0)
> - break;
> -
> - type = fdt_getprop(fdt, node, "device_type", &len);
> - if (type && strncmp(type, "memory", len) == 0) {
> - fdt_del_node(fdt, node);
> - continue;
> - }
> -
> - prev = node;
> - }
> -
> - /*
> * Delete all memory reserve map entries. When booting via UEFI,
> * kernel will use the UEFI memory map to find reserved regions.
> */
> --
> 1.8.3.1
>
>
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