[PATCH v2 04/12] arm64/efi: split off EFI init and runtime code for reuse by 32-bit ARM

On 16 November 2015 at 19:48, Russell King - ARM Linux
[off-list ref] wrote:

On Mon, Nov 16, 2015 at 07:32:29PM +0100, Ard Biesheuvel wrote:

quoted

+/*
+ * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
+ * non-early mapping of the UEFI system table and virtual mappings for all
+ * EFI_MEMORY_RUNTIME regions.
+ */
+static int __init arm64_enable_runtime_services(void)
+{
+     u64 mapsize;
+
+     if (!efi_enabled(EFI_BOOT)) {
+             pr_info("EFI services will not be available.\n");
+             return -1;
+     }
+
+     if (efi_runtime_disabled()) {
+             pr_info("EFI runtime services will be disabled.\n");
+             return -1;
+     }
+
+     pr_info("Remapping and enabling EFI services.\n");
+
+     mapsize = memmap.map_end - memmap.map;
+     memmap.map = (__force void *)ioremap_cache(memmap.phys_map,
+                                                mapsize);
+     if (!memmap.map) {
+             pr_err("Failed to remap EFI memory map\n");
+             return -1;
+     }
+     memmap.map_end = memmap.map + mapsize;
+     efi.memmap = &memmap;
+
+     efi.systab = (__force void *)ioremap_cache(efi_system_table,
+                                                sizeof(efi_system_table_t));
+     if (!efi.systab) {
+             pr_err("Failed to remap EFI System Table\n");
+             return -1;
+     }
+     set_bit(EFI_SYSTEM_TABLES, &efi.flags);
+
+     if (!efi_virtmap_init()) {
+             pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
+             return -1;
+     }
+
+     /* Set up runtime services function pointers */
+     efi_native_runtime_setup();
+     set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+
+     efi.runtime_version = efi.systab->hdr.revision;
+
+     return 0;
+}
+early_initcall(arm64_enable_runtime_services);

The above ought to be fixed - initcalls return negative errno numbers,
so returning -1 from them is really not acceptable.  (The original code
was doing the same - so it should be fixed as a separate patch.)

Indeed. I will add a patch to v3 to address this.