On Wed, Aug 26, 2015 at 10:06:30AM +0200, Ard Biesheuvel wrote:
> 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.
>
> Now that the UEFI initialization has moved to an earlier stage, we can
> actually just ignore any memblocks that are installed after we have
> processed 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>
> ---
> arch/arm64/mm/init.c | 10 ++++++++
> drivers/firmware/efi/libstub/fdt.c | 24 +-------------------
> 2 files changed, 11 insertions(+), 23 deletions(-)
Nice cleanup.
Acked-by: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index ab25fde7397c..ecbc051bc66b 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -379,6 +379,16 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
> {
> const u64 phys_offset = __pa(PAGE_OFFSET);
>
> + /*
> + * This callback will be invoked both when booting via UEFI and when
> + * booting via DT only. In the former case, we need to ignore memory
> + * nodes in the DT since UEFI is authoritative when it comes to the
> + * memory map. So ignore any invocations of this callback after
> + * EFI_MEMMAP has been set.
> + */
> + if (efi_enabled(EFI_MEMMAP))
> + return;
> +
> if (!PAGE_ALIGNED(base)) {
> if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
> pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
> diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
> index ef5d764e2a27..343e7992bd8f 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.
> */
> --
> 1.9.1
>
--
To unsubscribe from this list: send the line "unsubscribe linux-efi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
