On Mon, Nov 21, 2016 at 11:46:51AM +0000, David Howells wrote: > Lukas Wunner <lukas@xxxxxxxxx> wrote: > > We already have the efi_call_early() macro to call boot services > > in a manner that works across all arches and bitness variants. > > > > In 4.10 there will be an efi_call_proto() macro to allow the same > > for protocol calls: > > http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?h=efi/core&id=3552fdf29f01 > > > > I suggest adding an efi_call_runtime() macro for arch- and bitness- > > agnostic runtime services calls, like this: > > > > #define efi_call_runtime(f, ...) \ > > __efi_early()->call(efi_table_attr(efi_runtime_services, f, \ > > __efi_early()->runtime_services), __VA_ARGS__) > > > > For this to work you need to add a runtime_services attribute to struct > > efi_config, this requires modifying head_32.S and head_64.S, use commit > > 0a637ee61247 ("x86/efi: Allow invocation of arbitrary boot services") > > as a template. > > > > If you define corresponding efi_call_runtime() macros for ARM, you > > should indeed be able to share this function across arches. > > I'm not sure why I need to do this if I replace get_secure_boot() from my > patch with a call to efi_get_secureboot(). You need to do this to make the code run correctly in mixed mode (64 bit CPU, but 32-bit EFI). This dereferences efi_system_table_t *sys_table_arg as well as efi_runtime_services_t *runtime: efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable; The problem is that efi_system_table_t and efi_runtime_services_t uses 64-bit wide elements when compiled on 64-bit (unsigned long or void *). They need to be cast to efi_system_table_32_t and efi_runtime_services_32_t at runtime if EFI is 32-bit. The efi_call_early() and efi_call_proto() macros do this automatically. I suggest that you add efi_call_runtime() for symmetry. Thanks, Lukas -- 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
