From 4a1202765ddf4e5bb3143c0a859ee37f8fcf9b85 Mon Sep 17 00:00:00 2001 From: Alastair D'Silva Date: Tue, 19 Jul 2016 14:03:52 +1000 Subject: [PATCH] powerpc: Add module autoloading based on CPU features This patch provides the necessary infrastructure to allow drivers to be automatically loaded via udev. It implements the minimum required to be able to use module_cpu_feature_match() to trigger the GENERIC_CPU_AUTOPROBE mechanisms. The features exposed are a mirror of the cpu_user_features (converted to an offset from a mask). This decision was made to ensure that the behavior between features for module loading and userspace are consistent. Signed-off-by: Alastair D'Silva [mpe: Only define the bits we currently need] Signed-off-by: Michael Ellerman --- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/cpufeature.h | 40 +++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) create mode 100644 arch/powerpc/include/asm/cpufeature.h diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 9b6d36b87ee1..a5e0b47f7f20 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -165,6 +165,7 @@ config PPC select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS + select GENERIC_CPU_AUTOPROBE config GENERIC_CSUM def_bool CPU_LITTLE_ENDIAN diff --git a/arch/powerpc/include/asm/cpufeature.h b/arch/powerpc/include/asm/cpufeature.h new file mode 100644 index 000000000000..19e6290699ea --- /dev/null +++ b/arch/powerpc/include/asm/cpufeature.h @@ -0,0 +1,40 @@ +/* + * CPU feature definitions for module loading, used by + * module_cpu_feature_match(), see asm/cputable.h for powerpc CPU features. + * + * Copyright 2016 Alastair D'Silva, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef __ASM_POWERPC_CPUFEATURE_H +#define __ASM_POWERPC_CPUFEATURE_H + +#include + +/* Keep these in step with powerpc/include/asm/cputable.h */ +#define MAX_CPU_FEATURES (2 * 32) + +/* + * Currently we don't have a need for any of the feature bits defined in + * cpu_user_features. When we do, they should be defined such as: + * + * #define PPC_MODULE_FEATURE_32 (ilog2(PPC_FEATURE_32)) + */ + +#define PPC_MODULE_FEATURE_VEC_CRYPTO (32 + ilog2(PPC_FEATURE2_VEC_CRYPTO)) + +#define cpu_feature(x) (x) + +static inline bool cpu_have_feature(unsigned int num) +{ + if (num < 32) + return !!(cur_cpu_spec->cpu_user_features & 1UL << num); + else + return !!(cur_cpu_spec->cpu_user_features2 & 1UL << (num - 32)); +} + +#endif /* __ASM_POWERPC_CPUFEATURE_H */