From 500899c2cc3e3f06140373b587a69d30650f2d9d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 8 Apr 2016 15:50:23 -0700 Subject: [PATCH] efi: ARM/arm64: ignore DT memory nodes instead of removing them 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. Reviewed-by: Matt Fleming Acked-by: Steve Capper Signed-off-by: Ard Biesheuvel Signed-off-by: David Daney Signed-off-by: Will Deacon --- 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 aa1f743152a2..5d6945b761dc 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); + 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 6dba78aef337..e58abfa953cc 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; @@ -53,28 +53,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, if (status != 0) 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. -- GitLab